Dataset Viewer
prompt
stringlengths 2.91k
132k
| answer
stringlengths 4
245
|
|---|---|
Relavent Documents:
Document 0:::
Following is a list of dams and reservoirs in Puerto Rico.
The below list is incomplete. The National Inventory of Dams, maintained by the U.S. Army Corps of Engineers, defines any "major dam" as being tall with a storage capacity of at least , or of any height with a storage capacity of .
Dams and reservoirs in Puerto Rico
Lago Caonillas, Utuado, Puerto Rico Electric Power Authority (PREPA)
Lago Carite, Guayama, PREPA
Carraízo Dam and Lago Loíza, Trujillo Alto, Puerto Rico Aqueducts and Sewers Authority (PRASA)
Lago Cerrillos, Ponce, United States Army Corps of Engineers (USACE)
Lago de Cidra, Cidra, PRASA
Coamo Dam, between Coamo and Santa Isabel, PREPA
Lago Dos Bocas, between Arecibo and Utuado municipalities, PREPA
Lago Guajataca, between San Sebastián, Quebradillas and Isabela municipalities, PREPA
Lago Guayabal, Juana Díaz, PREPA
Lago El Guineo (Río Toro Negro), Villalba, PREPA
Lago Garzas, Peñuelas, PREPA
Lago La Plata, Toa Alta, PRASA
Patillas Dam, Patillas, PREPA
Portugués Dam, Ponce, USACE
Río Blanco Project, Naguabo, PREPA
El Salto #1 and El Salto #2, Comerío
Lago Toa Vaca, Villalba, PRASA
Yauco Project, Yauco, PREPA
Gallery
See also
List of rivers in Puerto Rico
References
External links
USGS List of Reservoirs in Puerto Rico
Document 1:::
Magnetic 2D materials or magnetic van der Waals materials are two-dimensional materials that display ordered magnetic properties such as antiferromagnetism or ferromagnetism. After the discovery of graphene in 2004, the family of 2D materials has grown rapidly. There have since been reports of several related materials, all except for magnetic materials. But since 2016 there have been numerous reports of 2D magnetic materials that can be exfoliated with ease, similarly to graphene.
The first few-layered van der Waals magnetism was reported in 2017 (Cr2Ge2Te6, and CrI3). One reason for this seemingly late discovery is that thermal fluctuations tend to destroy magnetic order for 2D magnets more easily compared to 3D bulk. It is also generally accepted in the community that low dimensional materials have different magnetic properties compared to bulk. This academic interest that transition from 3D to 2D magnetism can be measured has been the driving force behind much of the recent works on van der Waals magnets. Much anticipated transition of such has been since observed in both antiferromagnets and ferromagnets: FePS3, Cr2Ge2Te6, CrI3, NiPS3, MnPS3, Fe3GeTe2
Although the field has been only around since 2016, it has become one of the most active fields in condensed matter physics and materials science and engineering. There have been several review articles written up to highlight its future and promise.
Overview
Magnetic van der Waals materials is a new addition to the growing list of 2d materials. The special feature of these new materials is that they exhibit a magnetic ground state, either antiferromagnetic or ferromagnetic, when they are thinned down to very few sheets or even one layer of materials. Another, probably more important, feature of these materials is that they can be easily produced in few layers or monolayer form using simple means such as scotch tape, which is rather uncommon among other magnetic materials like oxide magnets.
Interest in these
Document 2:::
Unified Video Decoder (UVD, previously called Universal Video Decoder) is the name given to AMD's dedicated video decoding ASIC. There are multiple versions implementing a multitude of video codecs, such as H.264 and VC-1.
UVD was introduced with the Radeon HD 2000 Series and is integrated into some of AMD's GPUs and APUs. UVD occupies a considerable amount of the die surface at the time of its introduction and is not to be confused with AMD's Video Coding Engine (VCE).
As of AMD Raven Ridge (released January 2018), UVD and VCE were succeeded by Video Core Next (VCN).
Overview
The UVD is based on an ATI Xilleon video processor, which is incorporated onto the same die as the GPU and is part of the ATI Avivo HD for hardware video decoding, along with the Advanced Video Processor (AVP). UVD, as stated by AMD, handles decoding of H.264/AVC, and VC-1 video codecs entirely in hardware.
The UVD technology is based on the Cadence Tensilica Xtensa processor, which was originally licensed by ATI Technologies Inc. in 2004.
UVD/UVD+
In early versions of UVD, video post-processing is passed to the pixel shaders and OpenCL kernels. MPEG-2 decoding is not performed within UVD, but in the shader processors. The decoder meets the performance and profile requirements of Blu-ray and HD DVD, decoding H.264 bitstreams up to a bitrate of 40 Mbit/s. It has context-adaptive binary arithmetic coding (CABAC) support for H.264/AVC.
Unlike video acceleration blocks in previous generation GPUs, which demanded considerable host-CPU involvement, UVD offloads the entire video-decoder process for VC-1 and H.264 except for video post-processing, which is offloaded to the shaders. MPEG-2 decode is also supported, but the bitstream/entropy decode is not performed for MPEG-2 video in hardware.
Previously, neither ATI Radeon R520 series' ATI Avivo nor NVidia Geforce 7 series' PureVideo assisted front-end bitstream/entropy decompression in VC-1 and H.264 - the host CPU performed this work. UVD han
Document 3:::
Sliplining is a technique for repairing leaks or restoring structural stability to an existing pipeline. It involves installing a smaller, "carrier pipe" into a larger "host pipe", grouting the annular space between the two pipes, and sealing the ends. Sliplining has been used since the 1940s.
The most common material used to slipline an existing pipe is high-density polyethylene (HDPE), but fiberglass-reinforced pipe (FRP) and PVC are also common. Sliplining can be used to stop infiltration and restore structural integrity to an existing pipe. The most common size is (8"-60"), but sliplining can occur in any size given appropriate access and a new pipe small or large enough to install.
Installation methods
There are two methods used to install a slipline: continuous and segmental.
Continuous sliplining uses a long continuous pipe, such as HDPE, Fusible PVC, or Welded Steel Pipe, that are connected into continuous pieces of any length prior to installation. The continuous carrier pipe is pulled through the existing host pipe starting at an insertion pit and continuing to a receiving pit. Either the insertion pit, the receiving pit, or both can be manholes or other existing access points if the size and material of the new carrier pipe can manoeuvre the existing facilities.
Segmental sliplining is very similar to continuous sliplining. The difference is primarily based on the pipe material used as the new carrier pipe. When using any bell and spigot pipe such as FRP, PVC, HDPE or Spirally Welded Steel Pipe, the individual pieces of pipe are lowered into place, pushed together, and pushed along the existing pipe corridor.
Using either method the annular space between the two pipes must be grouted. In the case of sanitary sewer lines, the service laterals must be reconnected via excavation.
Advantages
Sliplining is generally a very cost-effective rehabilitation method. It is also very easy to install and requires tools and equipment widely available to any pi
Document 4:::
In organic chemistry, a moiety ( ) is a part of a molecule that is given a name because it is identified as a part of other molecules as well.
Typically, the term is used to describe the larger and characteristic parts of organic molecules, and it should not be used to describe or name smaller functional groups of atoms that chemically react in similar ways in most molecules that contain them. Occasionally, a moiety may contain smaller moieties and functional groups.
A moiety that acts as a branch extending from the backbone of a hydrocarbon molecule is called a substituent or side chain, which typically can be removed from the molecule and substituted with others.
The term is also used in pharmacology, where an active moiety is the part of a molecule responsible for the physiological or pharmacological action of a drug.
Active moiety
In pharmacology, an active moiety is the part of a molecule or ion—excluding appended inactive portions—that is responsible for the physiological or pharmacological action of a drug substance. Inactive appended portions of the drug substance may include either the alcohol or acid moiety of an ester, a salt (including a salt with hydrogen or coordination bonds), or other noncovalent derivative (such as a complex, chelate, or clathrate). The parent drug may itself be an inactive prodrug and only after the active moiety is released from the parent in free form does it become active.
See also
Moiety conservation
Moiety, each of the two kinship groups in some Indigenous societies
References
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is a sag in geological terms?
A. A raised area of land
B. A depressed, persistent, low area
C. A type of mountain
D. A large body of water
Answer: | B. A depressed, persistent, low area |
Relavent Documents:
Document 0:::
Madrid Río is an urban park in the Spanish capital Madrid, built along an urban stretch of the Manzanares River following the burial of the M-30 bypass road in this area. It is the result of a project led by the architect Ginés Garrido, who won the international ideas competition organised by the Madrid City Council in 2005 to redevelop the area.
The project started with the idea of recovering the banks of the Manzanares River for the use and enjoyment of the citizens. The section of the river that is now known as Madrid Río is the section that was boxed in by the M-30 bypass road, a road that isolated the river between the two directions of the highway as well as creating a barrier and fracture between the two sides of the city, the district of Arganzuela on the left bank, and the districts of Latina, Carabanchel and Usera on the right bank. The connection of the M-30 with the A-5 motorway, the road to Extremadura, separated the city in an impassable way from Casa de Campo, Madrid's largest park. The project involved the undergrounding of the M-30 in this area as well as that section of the A-5 running parallel to Casa de Campo.
There are seven dams that regulate the river as it passes through the city. They receive the waters of the Manzanares River after passing through the Santillana reservoir, in Manzanares el Real, and the El Pardo reservoir, in the municipality of Madrid, which is why they are numbered from 3 to 9. Their mechanisms and locks have been repaired and the dams have been used for the new system of crossings. Initially, the project for the renaturation of the Manzanares River as it passes through Madrid Río contemplated the opening of all the dams, except the last one, to create the conditions that would make it possible for the Madrid Río rowing school to train, but finally, contrary to what was first agreed and due to pressure from the local residents, it was also decided to also open the last one so that the river could flow freely.
The water level has been dropped as the natural flow of the river has been restored. Accessible wooden boards and fish ladders have been added to encourage the continuity of the underwater fauna along the river. There has been a noticeable improvement in avian biodiversity along the river with herons and kingfishers being regular visitors.
The Madrid Río has received the Veronica Rudge Green Prize in Urban Design from Harvard University's Graduate School of Design in 2015. The architects were Ginés Garrido (of Burgos & Garrido), Porras La Casta, Rubio & Álvarez-Sala, and West 8.
Notes
External links
Document 1:::
1B-LSD (N1-butyryl-lysergic acid diethylamide) is an acylated derivative of lysergic acid diethylamide (LSD), which has been sold as a designer drug. In tests on mice it was found to be an active psychedelic, though with only around 1/7 the potency of LSD itself.
Legal status
1B-LSD is illegal in Singapore. Sweden's public health agency suggested classifying 1B-LSD as a hazardous substance, on June 24, 2019.
Document 2:::
Digistar is the first computer graphics-based planetarium projection and content system. It was designed by Evans & Sutherland and released in 1983. The technology originally focused on accurate and high quality display of stars, including for the first time showing stars from points of view other than Earth's surface, travelling through the stars, and accurately showing celestial bodies from different times in the past and future. Beginning with the Digistar 3 the system now projects full-dome video.
Projector
Unlike modern full-dome systems, which use LCD, DLP, SXRD, or laser projection technology, the Digistar projection system was designed for projecting bright pinpoints of light representing stars. This was accomplished using a calligraphic display, a form of vector graphics, rather than raster graphics. The heart of the Digistar projector is a large cathode-ray tube (CRT). A phosphor plate is mounted atop the tube, and light is then dispersed by a large lens with a 160 degree field of view to cover the planetarium dome. The original lens bore the inscription: "August 1979 mfg. by Lincoln Optical Corp., L.A., CA for Evans and Sutherland Computer Corp., SLC, UT, Digital planetarium CRT projection lens, 43mm, f2.8, 160 degree field of view".
The coordinates of the stars and wire-frame models to be displayed by the projector were stored in computer RAM in a display list. The display would read each set of coordinates in turn and drive the CRT's electron beam directly to those coordinates. If the electron beam was enabled while being moved a line would be painted on the phosphor plate. Otherwise, the electron beam would be enabled once at its destination and a star would be painted. Once all coordinates in the display list had been processed, the display would repeat from the top of the display list.
Thus, the shorter the display list the more frequently the electron beam would refresh the charge on a given point on the phosphor plate, making the projection of t
Document 3:::
Cooling load is the rate at which sensible and latent heat must be removed from the space to maintain a constant space dry-bulb air temperature and humidity. Sensible heat into the space causes its air temperature to rise while latent heat is associated with the rise of the moisture content in the space. The building design, internal equipment, occupants, and outdoor weather conditions may affect the cooling load in a building using different heat transfer mechanisms. The SI units are watts.
Overview
The cooling load is calculated to select HVAC equipment that has the appropriate cooling capacity to remove heat from the zone. A zone is typically defined as an area with similar heat gains, similar temperature and humidity control requirements, or an enclosed space within a building with the purpose to monitor and control the zone's temperature and humidity with a single sensor e.g. thermostat. Cooling load calculation methodologies take into account heat transfer by conduction, convection, and radiation. Methodologies include heat balance, radiant time series, cooling load temperature difference, transfer function, and sol-air temperature. Methods calculate the cooling load in either steady state or dynamic conditions and some can be more involved than others. These methodologies and others can be found in ASHRAE handbooks, ISO Standard 11855, European Standard (EN) 15243, and EN 15255. ASHRAE recommends the heat balance method and radiant time series methods.
Differentiation from heat gains
The cooling load of a building should not be confused with its heat gains. Heat gains refer to the rate at which heat is transferred into or generated inside a building. Just like cooling loads, heat gains can be separated into sensible and latent heat gains that can occur through conduction, convection, and radiation. Thermophysical properties of walls, floors, ceilings, and windows, lighting power density (LPD), plug load density, occupant density, and equipment efficiency
Document 4:::
A Hagenhufendorf (German: also Bachhufendorf, Hagenhufensiedlung or Hägerhufensiedlung) is an elongated settlement, similar to a Reihendorf, laid out along a road running parallel to a stream, whereby only one side of the road has houses, whilst on the opposite side are the hides (Hufen), the handkerchief-shaped farmer's fields of medieval origin, about 20 to 40 morgens in area.
Name
This German term is probably derived from Hagenrecht ("hedging right"), i.e. the owner had a right to enclose the land he used. This went even further for the Hägerhufensiedlungen, where there was a Hägerjunker in charge and special courts dealing with enclosure issues, the Hägergerichte.
Description
The Hagenhufensiedlung was a form of planned settlement typical of the High Middle Ages that consisted of individually owned strips of land that were strung together in a line. The hides were as wide as the farmstead, but could be several hundred metres long.
The enclosed plots were used as vegetable gardens and for keeping small animals. The stream at the back of the farmhouses supplied the necessary water. From this type of settlement, long linear villages developed like Auhagen, Wiedensahl, Isernhagen, Kathrinhagen or Rodewald in Lower Saxony. Hagenhufensiedlungen may be found from the Taunus region as far as Western Pomerania. The Hägerhufensiedlung is restricted to a region in the area of the Weser Uplands, Leine Uplands and Lippe.
Origin
The Hagenhufendörfer arose from the planned settlement of forested areas, predominantly in the 13th century, with the aim of clearing and cultivating the land. These villages had a lokator with a double hide (Doppelhufe).
The Hägerhufensiedlungen go back to the 11th-century Eschershausen Treaty. Although they had no double hide and no lokator, they did have special enclosure rights (Hägerrecht).
Extent
Hagenhufendörfer are especially common in the Börde regions, on the North German Plain immediately north of the German Central Uplands. The be
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What was the main goal of the Madrid Río project initiated by Ginés Garrido?
A. To construct a new highway
B. To recover the banks of the Manzanares River for public use
C. To build luxury apartments along the river
D. To create a dam system for flood prevention
Answer: | B. To recover the banks of the Manzanares River for public use |
Relavent Documents:
Document 0:::
In the Taroom district in the Dawson River valley of Queensland, Australia, a boggomoss (pl. boggomossi or boggomosses) is a mound spring. Boggomosses range in form from small muddy swamps to elevated peat bogs or swamps, up to 150 meters across scattered among dry woodland communities, which form part of the Springsure Group of Great Artesian Basin springs. They are rich in invertebrates and form a vital chain of permanently moist oases in an otherwise dry environment.
The origin of the term boggomoss is not known, but is most likely a compound of the words bog and moss. "Boggomoss creek" in the Parish of Fernyside appears on very early maps.
Environment
The spring flow rate is usually in the range of 0.5 to 2.0 litres per second (8th magnitude spring), however some large boggomosses have a flow rate of up to 10.0 litres per second (7th magnitude spring).
A report commissioned by the Queensland Department of Environment defined four boggomoss vegetation types with distinct environmental relations:
Group 1 associated with sandy and relatively infertile soils.
Group 2 associated with fertile and heavy surface soils and relatively large mounds.
Group 3 associated with fertile and heavy surface soils, but with little or no mound development (probably young springs).
Group 4 are linear in shape and flood prone at the base of a gorge
Sources
Adclarkia dawsonensis (Boggomoss Snail, Dawson Valley Snail)
Document 1:::
A col in geomorphology is the lowest point on a mountain ridge between two peaks. It may also be called a gap or pass. Particularly rugged and forbidding cols in the terrain are usually referred to as notches. They are generally unsuitable as mountain passes, but are occasionally crossed by mule tracks or climbers' routes. Derived from the French ("collar, neck") from Latin collum, "neck", the term tends to be associated more with mountain than hill ranges. The distinction with other names for breaks in mountain ridges such as saddle, wind gap or notch is not sharply defined and may vary from place to place. Many double summits are separated by prominent cols.
The height of a summit above its highest col (called the key col) is effectively a measure of a mountain's topographic prominence.
Cols lie on the line of the watershed between two mountains, often on a prominent ridge or arête. For example, the highest col in Austria, the ("Upper Glockner Col", ) lies between the Kleinglockner () and Grossglockner () mountains, giving the Kleinglockner a minimum prominence of 17 metres.
See also
Saddle (landform)
Document 2:::
Mammoplasia is the normal or spontaneous enlargement of human breasts. Mammoplasia occurs normally during puberty and pregnancy in women, as well as during certain periods of the menstrual cycle. When it occurs in males, it is called gynecomastia and is considered to be pathological. When it occurs in females and is extremely excessive, it is called macromastia (also known as gigantomastia or breast hypertrophy) and is similarly considered to be pathological. Mammoplasia may be due to breast engorgement, which is temporary enlargement of the breasts caused by the production and storage of breast milk in association with lactation and/or galactorrhea (excessive or inappropriate production of milk). Mastodynia (breast tenderness/pain) frequently co-occurs with mammoplasia.
During the luteal phase (latter half) of the menstrual cycle, due to increased mammary blood flow and/or premenstrual fluid retention caused by high circulating concentrations of estrogen and/or progesterone, the breasts temporarily increase in size, and this is experienced by women as fullness, heaviness, swollenness, and a tingling sensation.
Mammoplasia can be an effect or side effect of various drugs, including estrogens, antiandrogens such as spironolactone, cyproterone acetate, bicalutamide, and finasteride, growth hormone, and drugs that elevate prolactin levels such as D2 receptor antagonists like antipsychotics (e.g., risperidone), metoclopramide, and domperidone and certain antidepressants like selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs). The risk appears to be less with serotonin-norepinephrine reuptake inhibitors (SNRIs) like venlafaxine. The "atypical" antidepressants mirtazapine and bupropion do not increase prolactin levels (bupropion may actually decrease prolactin levels), and hence there may be no risk with these agents. Other drugs that have been associated with mammoplasia include D-penicillamine, bucillamine, neothetazone, ciclosporin,
Document 3:::
Glycoprotein 130 (also known as gp130, IL6ST, IL6R-beta or CD130) is a transmembrane protein which is the founding member of the class of tall cytokine receptors. It forms one subunit of the type I cytokine receptor within the IL-6 receptor family. It is often referred to as the common gp130 subunit, and is important for signal transduction following cytokine engagement. As with other type I cytokine receptors, gp130 possesses a WSXWS amino acid motif that ensures correct protein folding and ligand binding. It interacts with Janus kinases to elicit an intracellular signal following receptor interaction with its ligand. Structurally, gp130 is composed of five fibronectin type-III domains and one immunoglobulin-like C2-type (immunoglobulin-like) domain in its extracellular portion.
Characteristics
The members of the IL-6 receptor family are all complex with gp130 for signal transduction. For example, IL-6 binds to the IL-6 Receptor. The complex of these two proteins then associates with gp130. This complex of 3 proteins then homodimerizes to form a hexameric complex which can produce downstream signals. There are many other proteins which associate with gp130, such as cardiotrophin 1 (CT-1), leukemia inhibitory factor (LIF), ciliary neurotrophic factor (CNTF), oncostatin M (OSM), and IL-11. There are also several other proteins which have structural similarity to gp130 and contain the WSXWS motif and preserved cysteine residues. Members of this group include LIF-R, OSM-R, and G-CSF-R.
Loss of gp130
gp130 is an important part of many different types of signaling complexes. Inactivation of gp130 is lethal to mice. Homozygous mice who are born show a number of defects including impaired development of the ventricular myocardium. Haematopoietic effects included reduced numbers of stem cells in the spleen and liver.
Signal transduction
gp130 has no intrinsic tyrosine kinase activity. Instead, it is phosphorylated on tyrosine residues after complexing with other
Document 4:::
Peter Cameron (1847 – 1 December 1912 in New Mills, Derbyshire) was an English amateur entomologist who specialised in Hymenoptera.
An artist, Cameron worked in the dye industry and in calico printing. He described many new species; his collection, including type material, is now in the Natural History Museum. He suffered from poor health and lack of employment. Latterly, he lived in New Mills and was supported by scholarships from the Royal Society.
He loaned specimens to Jean-Jacques Kieffer, a teacher and Catholic priest in Bitche, Lorraine, who also named species after Cameron.
Some of Cameron's taxonomic work is not very well regarded. Upon his death Claude Morley wrote, "Peter Cameron is dead, as was announced by most of the halfpenny papers on December 4th. What can we say of his life? Nothing; for it concerns us in no way. What shall we say of his work? Much, for it is entirely ours, and will go down to posterity as probably the most prolific and chaotic output of any individual for many years past." Similarly, American entomologist Richard M. Bohart "wound up with the thankless task of sorting through Cameron's North American contributions to a small group of wasps known as the Odynerini. Of the hundred or so names Cameron proposed within the group, almost all, Bohart found, were invalid."
The Panamanian oak gall wasp Callirhytis cameroni described 2014 is named in his honor.
Works
A Monograph of the British Phytophagous Hymenoptera Ray Society (1882–1893)
Hymenoptera volumes of the Biologia Centrali-Americana, volumes 1–2 (1883–1900) and (1888–1900)
A complete list is given in external links below.
External links
Publications of Peter Cameron
Manuscript collection
BHL Hymenoptera Orientalis: or contributions to a knowledge of the Hymenoptera of the Oriental zoological region. Manchester :Literary and Philosophical Society,1889–1903.
Digital Version of Biologia Centrali-Americana
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the main argument presented by critics of the GAARlandia hypothesis regarding the colonization of the Greater Antilles?
A. They support the hypothesis based on geological evidence.
B. They believe oceanic dispersal is the best explanation for colonization.
C. They argue that multiple lineages colonized simultaneously.
D. They find ample support from studies of individual lineages.
Answer: | B. They believe oceanic dispersal is the best explanation for colonization. |
Relavent Documents:
Document 0:::
Sonata was a 3D building design software application developed in the early 1980s and now regarded as the forerunner of today's building information modeling applications.
Sonata was commercially released in 1986, having been developed by Jonathan Ingram independently and was sold to T2 Solutions (renamed from GMW Computers in 1987 - which was eventually bought by Alias|Wavefront), and was sold as a successor to GMW's RUCAPS. It ran on workstation computer hardware (by contrast, other 2D computer-aided design (CAD) systems could run on personal computers). The system was not expensive, according to Michael Phiri. Reiach Hall purchased "three Sonata workstations on Silicon Graphics machines, at a total cost of approximately £2000 each" [1990 prices]. Approximately 1,000 seats were sold between 1985 and 1992. However, as a BIM application, in addition to geometric modelling, it could model complete buildings, including complex parametrics, costs and staging of the construction process.
Archicad founder Gábor Bojár has acknowledged that Sonata "was more advanced in 1986 than Archicad at that time", adding that it "surpassed already the matured definition of 'BIM' specified only about one and a half decade later".
Many projects were designed and built using Sonata, including Peddle Thorp Architect's Rod Laver Arena in 1987, and Gatwick Airport North Terminal Domestic Facility by Taylor Woodrow. The US-based architect HKS used the software in 1992 to design a horse racing facility (Lone Star Park in Grand Prairie, Texas) and subsequently purchased the successor product, Reflex.
Target Australia Pty. Ltd. the Australian discount department store retailer bought two Sonata licences in 1992 to replace two RUCAPS workstations originally from Coles Supermarkets. The software was run on two Silicon Graphics IRIS Indigo workstations. Staff were trained to use the software including the parametric language. The simple but powerful parametrics enable productivity gains in doc
Document 1:::
EL Aquilae, also known as Nova Aquilae 1927 was a nova that appeared in 1927. It was discovered by Max Wolf on photographic plates taken at Heidelberg Observatory on 30 and 31 July 1927 when it had a photographic magnitude of 9. Subsequent searches of plates taken at the Harvard College Observatory showed the nova was fainter than magnitude 11.1 on 8 June 1927 and had flared to magnitude 6.4 on 15 June 1927. It declined from peak brightness at an average rate of 0.105 magnitudes per day, making it a fast nova, and ultimately dimmed to about magnitude 21. The 14.5 magnitude change from peak brightness to quiescence was unusually large for a nova.
All novae are binary stars, with a "donor" star orbiting a white dwarf so closely that matter is transferred from the donor to the white dwarf. Pagnotta & Schaefer argued that the donor star for the EL Aquilae system is a red giant, based on its position in an infrared color–color diagram. Tappert et al. suggest that Pagnotta & Schaefer misidentified EL Aquilae, and claim that EL Aquilae is probably an intermediate polar, a nova with a main sequence donor star, based on its eruption amplitude and color.
Notes
References
Document 2:::
The Barton decarboxylation is a radical reaction in which a carboxylic acid is converted to a thiohydroxamate ester (commonly referred to as a Barton ester). The product is then heated in the presence of a radical initiator and a suitable hydrogen donor to afford the decarboxylated product. This is an example of a reductive decarboxylation. Using this reaction it is possible to remove carboxylic acid moieties from alkyl groups and replace them with other functional groups. (See Scheme 1) This reaction is named after its developer, the British chemist and Nobel laureate Sir Derek Barton (1918–1998).
Mechanism
The reaction is initiated by homolytic cleavage of a radical initiator, in this case 2,2'-azobisisobutyronitrile (AIBN), upon heating. A hydrogen is then abstracted from the hydrogen source (tributylstannane in this case) to leave a tributylstannyl radical that attacks the sulfur atom of the thiohydroxamate ester. The N-O bond of the thiohydroxamate ester undergoes homolysis to form a carboxyl radical which then undergoes decarboxylation and carbon dioxide (CO2) is lost. The remaining alkyl radical (R·) then abstracts a hydrogen atom from remaining tributylstannane to form the reduced alkane (RH). (See Scheme 2) The tributyltin radical enters into another cycle of the reaction until all thiohydroxamate ester is consumed.
N-O bond cleavage of the Barton ester can also occur spontaneously upon heating or by irradiation with light to initiate the reaction. In this case a radical initiator is not required but a hydrogen-atom (H-atom) donor is still necessary to form the reduced alkane (RH). Alternative H-atom donors to tributylstannane include tertiary thiols and organosilanes. The relative expense, smell, and toxicity associated with tin, thiol or silane reagents can be avoided by carrying the reaction out using chloroform as both solvent and H-atom donor.
It is also possible to functionalize the alkyl radical by use of other radical trapping species (X-Y + R·
Document 3:::
Inspur Group is an information technology conglomerate in the People's Republic of China focusing on cloud computing, big data, key application hosts, servers, storage, artificial intelligence and ERP. On April 18, 2006, Inspur changed its English name from Langchao to Inspur. It is listed on the SSE, SZSE, and SEHK.
History
In 2005, Microsoft invested US$20 million in the company. Inspur announced several agreements with virtualization software developer VMware on research and development of cloud computing technologies and related products. In 2009, Inspur acquired the Xi'an-based research and development facilities of Qimonda AG for 30 million Chinese yuan (around US$4 million). The centre had been responsible for design and development of Qimonda's DRAM products.
In 2011, Shandong Inspur Software Co., Ltd., Inspur Electronic Information Co., Ltd. and Inspur (Shandong) Electronic Information Company, established a cloud computing joint venture, with each holding a third.
U.S. sanctions
In June 2020, the United States Department of Defense published a list of Chinese companies operating in the U.S. that have ties to the People's Liberation Army, which included Inspur. In November 2020, Donald Trump issued an executive order prohibiting any American company or individual from owning shares in companies that the U.S. Department of Defense has listed as having links to the People's Liberation Army.
In March 2023, the United States Department of Commerce added Inspur to the Bureau of Industry and Security's Entity List. In March 2025, several Inspur subsidiaries were also added to the Entity List, including its Aivres Systems subsidiary.
See also
Inspur Server Series
References
Document 4:::
NIST Special Publication 800-92, "Guide to Computer Security Log Management", establishes guidelines and recommendations for securing and managing sensitive log data. The publication was prepared by Karen Kent and Murugiah Souppaya of the National Institute of Science and Technology and published under the SP 800-Series; a repository of best practices for the InfoSec community. Log management is essential to ensuring that computer security records are stored in sufficient detail for an appropriate period of time.
Background
Effective security event logging and log analysis is a critical component of any comprehensive security program within an organization. It is used to monitor system, network and application activity. It serves as a deterrent for unauthorized activity, as well as provides a means to detect and analyze an attack in order to allow the organization to mitigate or prevent similar attacks in the future. However, security professionals have a significant challenge to determine what events must be logged, where and how long to retain those logs, and how to analyze the enormous amount of information that can be generated. A deficiency in any of these areas can cause an organization to miss signs of unauthorized activity, intrusion, and loss of data, which creates additional risk.
Scope
NIST SP 800-92 provides a high-level overview and guidance for the planning, development and implementation of an effective security log management strategy. The intended audience for this publication include the general information security (InfoSec) community involved in incident response, system/application/network administration and managers.
NIST SP 800-92 defines a log management infrastructure as having 4 major functions:
General - log parsing, event filtering and event aggregation;
Log Storage - rotation, archival, compression, reduction, normalization, integrity checking;
Log Analysis - event correlation, viewing and reporting;
Disposal - clearing;
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What significant event occurred in 2006 regarding Inspur's branding?
A. Inspur changed its name from Langchao.
B. Inspur was acquired by Microsoft.
C. Inspur launched its first cloud computing product.
D. Inspur established a joint venture with VMware.
Answer: | A. Inspur changed its name from Langchao. |
Relavent Documents:
Document 0:::
Controlled vocabularies provide a way to organize knowledge for subsequent retrieval. They are used in subject indexing schemes, subject headings, thesauri, taxonomies and other knowledge organization systems. Controlled vocabulary schemes mandate the use of predefined, preferred terms that have been preselected by the designers of the schemes, in contrast to natural language vocabularies, which have no such restriction.
In library and information science
In library and information science, controlled vocabulary is a carefully selected list of words and phrases, which are used to tag units of information (document or work) so that they may be more easily retrieved by a search. Controlled vocabularies solve the problems of homographs, synonyms and polysemes by a bijection between concepts and preferred terms. In short, controlled vocabularies reduce unwanted ambiguity inherent in normal human languages where the same concept can be given different names and ensure consistency.
For example, in the Library of Congress Subject Headings (a subject heading system that uses a controlled vocabulary), preferred terms—subject headings in this case—have to be chosen to handle choices between variant spellings of the same word (American versus British), choice among scientific and popular terms (cockroach versus Periplaneta americana), and choices between synonyms (automobile versus car), among other difficult issues.
Choices of preferred terms are based on the principles of user warrant (what terms users are likely to use), literary warrant (what terms are generally used in the literature and documents), and structural warrant (terms chosen by considering the structure, scope of the controlled vocabulary).
Controlled vocabularies also typically handle the problem of homographs with qualifiers. For example, the term pool has to be qualified to refer to either swimming pool or the game pool to ensure that each preferred term or heading refers to only one concept.
Types u
Document 1:::
The HP Precision bus (also called HP-PB and HP-NIO)
is the data transfer bus of the proprietary Hewlett Packard architecture HP 3000 and later many variants of the HP 9000 series of UNIX systems. This bus has a 32-bit data path with an 8 MHz clock. It supports a maximum transfer rate of 23 MB/s in burst mode. That bus was also used to directly support the Programmable Serial Interface (PSI) cards, which offered multi-protocol support for networking, notably IBM Bisync and similar systems.The 920, 922 and 932 series supported up to three PSI cards, and up to five cards in the 948 and 958 series.
Two form factors/sizes of HP-PB expansion cards were sold: single and double.
32-bit data path width
32 MB/s maximum data rate
8 MHz maximum frequency
5 V signalling voltage
96-pin (32×3) female pin+socket card connector (Is this a DIN 41612 connector?)
External links
HP 3000 manuals
HP/PA buses on Openpa.net
Notes
Document 2:::
In the hyperbolic plane, as in the Euclidean plane, each point can be uniquely identified by two real numbers. Several qualitatively different ways of coordinatizing the plane in hyperbolic geometry are used.
This article tries to give an overview of several coordinate systems in use for the two-dimensional hyperbolic plane.
In the descriptions below the constant Gaussian curvature of the plane is −1. Sinh, cosh and tanh are hyperbolic functions.
Polar coordinate system
The polar coordinate system is a two-dimensional coordinate system in which each point on a plane is determined by a distance from a reference point and an angle from a reference direction.
The reference point (analogous to the origin of a Cartesian system) is called the pole, and the ray from the pole in the reference direction is the polar axis. The distance from the pole is called the radial coordinate or radius, and the angle is called the angular coordinate, or polar angle.
From the hyperbolic law of cosines, we get that the distance between two points given in polar coordinates is
Let , differentiating at :
we get the corresponding metric tensor:
The straight lines are described by equations of the form
where r0 and θ0 are the coordinates of the nearest point on the line to the pole.
Quadrant model system
The Poincaré half-plane model is closely related to a model of the hyperbolic plane in the quadrant Q = {(x,y): x > 0, y > 0}. For such a point the geometric mean and the hyperbolic angle produce a point (u,v) in the upper half-plane. The hyperbolic metric in the quadrant depends on the Poincaré half-plane metric. The motions of the Poincaré model carry over to the quadrant; in particular the left or right shifts of the real axis correspond to hyperbolic rotations of the quadrant. Due to the study of ratios in physics and economics where the quadrant is the universe of discourse, its points are said to be located by hyperbolic coordinates.
Cartesian-style coordinate systems
I
Document 3:::
A deadband or dead-band (also known as a dead zone or a neutral zone) is a band of input values in the domain of a transfer function in a control system or signal processing system where the output is zero (the output is 'dead' - no action occurs). Deadband regions can be used in control systems such as servoamplifiers to prevent oscillation or repeated activation-deactivation cycles (called 'hunting' in proportional control systems). A form of deadband that occurs in mechanical systems, compound machines such as gear trains is backlash.
Voltage regulators
In some power substations there are regulators that keep the voltage within certain predetermined limits, but there is a range of voltage in-between during which no changes are made, such as between 112 and 118 volts (the deadband is 6 volts), or between 215 and 225 volts (deadband is 10 volts).
Backlash
Gear teeth with slop (backlash) exhibit deadband. There is no drive from the input to the output shaft in either direction while the teeth are not meshed. Leadscrews generally also have backlash and hence a deadband, which must be taken into account when making position adjustments, especially with CNC systems. If mechanical backlash eliminators are not available, the control can compensate for backlash by adding the deadband value to the position vector whenever direction is reversed.
Hysteresis versus Deadband
Deadband is different from hysteresis. With hysteresis, there is no deadband and so the output is always in one direction or another. Devices with hysteresis have memory, in that previous system states dictate future states. Examples of devices with hysteresis are single-mode thermostats and smoke alarms. Deadband is the range in a process where no changes to output are made. Hysteresis is the difference in a variable depending on the direction of travel.
Thermostats
Simple (single mode) thermostats exhibit hysteresis. For example, the furnace in the basement of a house is adjusted automatically by
Document 4:::
A micronucleus is a small nucleus that forms whenever a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei during cell division. It usually is a sign of genotoxic events and chromosomal instability. Micronuclei are commonly seen in cancerous cells and may indicate genomic damage events that can increase the risk of developmental or degenerative diseases.
Micronuclei form during anaphase from lagging acentric chromosomes or chromatid fragments caused by incorrectly repaired or unrepaired DNA breaks or by nondisjunction of chromosomes. This improper segregation of chromosomes may result from hypomethylation of repeat sequences present in pericentromeric DNA, irregularities in kinetochore proteins or their assembly, a dysfunctional spindle apparatus, or flawed anaphase checkpoint genes. Micronuclei can contribute to genome instability by promoting a catastrophic mutational event called chromothripsis. Many micronucleus assays have been developed to test for the presence of these structures and determine their frequency in cells exposed to certain chemicals or subjected to stressful conditions.
The term micronucleus may also refer to the smaller nucleus in ciliate protozoans, such as the Paramecium. In mitosis it divides by fission, and in conjugation a pair of gamete micronuclei undergo reciprocal fusion to form a zygote nucleus, which gives rise to the macronuclei and micronuclei of the individuals of the next cycle of fission.
Discovery
Micronuclei in newly formed red blood cells in humans are known as Howell-Jolly bodies because these structures were first identified and described in erythrocytes by hematologists William Howell and Justin Jolly. These structures were later found to be associated with deficiencies in vitamins such as folate and B12. The relationship between formation of micronuclei and exposure to environmental factors was first reported in root tip cells exposed to ionizing radiation. Micronucleus inducti
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the maximum transfer rate of the HP Precision bus in burst mode?
A. 23 MB/s
B. 32 MB/s
C. 5 MB/s
D. 8 MB/s
Answer: | A. 23 MB/s |
Relavent Documents:
Document 0:::
The National Board for Respiratory Care (NBRC Inc. is a non-profit organization formed in 1960 with the purpose of awarding and maintaining credentialing for Respiratory Therapists in the United States. The NBRC is the only organization in the United States which develops certification examinations for Registered Respiratory Therapists (RRTs) and Certified Respiratory Therapists (CRTs). The NBRC also offers additional specialization credentialing for respiratory practitioners that hold its certifications. The CRT and RRT designations are the standard credential in respiratory care for licensure requirements in the portions of the United States that have enacted a Respiratory Care Act. States that license respiratory therapists sometimes require the practitioner to maintain their NBRC credentialing to maintain their license to practice. The NBRC is headquartered in Overland Park, Kansas. It has been in the Kansas City metropolitan area since 1974. The NBRC is located at 10801 Mastin St, Suite 300, Overland Park, KS 66210.
Certification levels
Entry level certification
Certification is the entry level and is separated as such by the NBRC. Certified Respiratory Therapists and Certified Pulmonary Function Technologists may require oversight and supervision by their advanced-practice counterparts.
Specialties
The NBRC has sub-specialties for the Respiratory Therapist designations. Both the CRT and the RRT are eligible to sit for additional credentialing but the CRT still requires the same supervision by the RRT in clinical applications.
Sleep Disorders Specialist — The sleep disorder specialist (RRT-SDS or CRT-SDS) is a credential recognized by the American Academy of Sleep Medicine for the role of Scoring in sleep studies.
Neonatal & Pediatric Specialist — The neonatal and pediatric specialist (RRT-NPS or CRT-NPS) is a respiratory therapist that may work in advanced care in pediatrics and neonatology centers and units.
Adult Critical Care Specialist — Th
Document 1:::
In architecture, the term xystum refers to a wall, promenade, alley, or open path. It can also refer to an atrium, ambulacrum, or parvis in front of a basilica. The term should not be confused with the ancient Greek architectural term xystus, meaning the covered portico of a gymnasium.
Sources
Document 2:::
An electronic control unit (ECU), also known as an electronic control module (ECM), is an embedded system in automotive electronics that controls one or more of the electrical systems or subsystems in a car or other motor vehicle.
Modern vehicles have many ECUs, and these can include some or all of the following: engine control module (ECM), powertrain control module (PCM), transmission control module (TCM), brake control module (BCM or EBCM), central control module (CCM), central timing module (CTM), general electronic module (GEM), body control module (BCM), and suspension control module (SCM). These ECUs together are sometimes referred to collectively as the car's computer though technically they are all separate computers, not a single one. Sometimes an assembly incorporates several individual control modules (a PCM often controls both the engine and the transmission).
Some modern motor vehicles have up to 150 ECUs. Embedded software in ECUs continues to increase in line count, complexity, and sophistication. Managing the increasing complexity and number of ECUs in a vehicle has become a key challenge for original equipment manufacturers (OEMs).
Types
Generic industry controller namingIs the naming of controllers where the logical thought of the controller's name implies the system the controller is responsible for controlling
Generic powertrainThe generic powertrain pertains to a vehicle's emission system and is the only regulated controller name.
Other controllersAll other controller names are decided upon by the individual OEM. The engine controller may have several different names, such as "DME", "Enhanced Powertrain", "PGM-FI" and many others.
Door control unit (DCU)
Engine control unit (ECU)not to be confused with electronic control unit, the generic term for all these devices
Electric power steering control unit (PSCU)Generally this will be integrated into the EPS power pack.
Human–machine interface (HMI)
Powertrain control module (PCM)Somet
Document 3:::
An aridity index (AI) is a numerical indicator of the degree of dryness of the climate at a given location. The American Meteorological Society defined it in meteorology and climatology, as "the degree to which a climate lacks effective, life-promoting moisture". Aridity is different from drought because aridity is permanent whereas drought is temporary. A number of aridity indices have been proposed (see below); these indicators serve to identify, locate or delimit regions that suffer from a deficit of available water, a condition that can severely affect the effective use of the land for such activities as agriculture or stock-farming.
Historical background and indices
Köppen
At the turn of the 20th century, Wladimir Köppen and Rudolf Geiger developed the concept of a climate classification where arid regions were defined as those places where the annual rainfall accumulation (in centimetres) is less than , where:
if rainfall occurs mainly in the cold season,
if rainfall is evenly distributed throughout the year, and
if rainfall occurs mainly in the hot season.
where is the mean annual temperature in Celsius.
This was one of the first attempts at defining an aridity index, one that reflects the effects of the thermal regime and the amount and distribution of precipitation in determining the native vegetation possible in an area. It recognizes the significance of temperature in allowing colder places such as northern Canada to be seen as humid with the same level of precipitation as some tropical deserts because of lower levels of potential evapotranspiration in colder places. In the subtropics, the allowance for the distribution of rainfall between warm and cold seasons recognizes that winter rainfall is more effective for plant growth that can flourish in the winter and go dormant in the summer than the same amount of summer rainfall during a warm-to-hot season. Thus a place like Athens, Greece that gets most of its rainfall in winter can be conside
Document 4:::
The Sepsis Six is the name given to a bundle of medical therapies designed to reduce mortality in patients with sepsis.
Drawn from international guidelines that emerged from the Surviving Sepsis Campaign the Sepsis Six was developed by The UK Sepsis Trust. (Daniels, Nutbeam, Laver) in 2006 as a practical tool to help healthcare professionals deliver the basics of care rapidly and reliably.
In 2011, The UK Sepsis Trust published evidence that use of the Sepsis Six was associated with a 50% reduction in mortality, a decreased length of stay in hospital, and fewer intensive care days. Though the authors urge caution in a causal interpretation of these findings.
The Sepsis Six consists of three diagnostic and three therapeutic steps – all to be delivered within one hour of the initial diagnosis of sepsis:
Titrate oxygen to a saturation target of 94%
Take blood cultures and consider source control
Administer empiric intravenous antibiotics
Measure serial serum lactates
Start intravenous fluid resuscitation
Commence accurate urine output measurement.
References
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What does the term "xystum" refer to in architecture?
A. A covered portico of a gymnasium
B. An open path or promenade
C. A type of decorative wall
D. A specific style of basilica
Answer: | B. An open path or promenade |
Relavent Documents:
Document 0:::
Vachellia rigidula, commonly known as blackbrush acacia or chaparro prieto, and also known as Acacia rigidula, is a species of shrub or small tree in the legume family, Fabaceae. Its native range stretches from Texas in the United States south to central Mexico. This perennial is not listed as being threatened. It reaches a height of . Blackbrush acacia grows on limestone hillsides and canyons.
Phytochemistry
A phytochemical study of V. rigidula by workers at the Texas A & M University Agricultural Research and Extension Center at Uvalde, TX, reported the presence of over forty alkaloids, including low amounts (up to around 15 ppm) of several phenolic amines that had previously been found by the same research group in the related species Senegalia berlandieri, but which otherwise are known only as products of laboratory synthesis. Compounds found in the highest concentrations (ranging from a few hundred to a few thousand ppm) were phenethylamine, tryptamine, tyramine, and β-Methylphenethylamine (that it can be misidentified as amphetamine). Other notable compounds reported were N,N-dimethyltryptamine, mescaline, and nicotine, although these were found in low concentrations (e.g. mescaline at 3-28 ppm).
The presence of such an unprecedented chemical range of psychoactive compounds, including ones not previously found in nature, in a single plant species has led to the suggestion that some of these findings may have resulted from cross-contamination or were possibly artifacts of the analytical technique.
Uses
Vachellia rigidula is used in weight loss dietary supplements because of the presence of chemical compounds claimed to stimulate beta-receptors to increase lipolysis and metabolic rate and decrease appetite.
Vachellia rigidula is also known as a large honey producer and early blooming plant for its native region.
Safety
In 2015, 52% of supplements labeled as containing Acacia rigidula were found to be adulterated with synthetic BMPEA, an amphetamine iso
Document 1:::
Foraminoplasty is a type of endoscopic surgery used to operate on the spine. It is considered a minimally invasive surgery technique and its endoscopic laser is legally regulated. Although most patients have benefited from foraminoplasty, the National Institute for Health and Care Excellence does not fully support it due to it not completing its randomised controlled clinical trial.
External links
http://ijssurgery.com/10.14444/1026
https://www.nice.org.uk/guidance/ipg31/informationforpublic
Document 2:::
A voltage doubler is an electronic circuit which charges capacitors from the input voltage and switches these charges in such a way that, in the ideal case, exactly twice the voltage is produced at the output as at its input.
The simplest of these circuits is a form of rectifier which take an AC voltage as input and outputs a doubled DC voltage. The switching elements are simple diodes and they are driven to switch state merely by the alternating voltage of the input. DC-to-DC voltage doublers cannot switch in this way and require a driving circuit to control the switching. They frequently also require a switching element that can be controlled directly, such as a transistor, rather than relying on the voltage across the switch as in the simple AC-to-DC case.
Voltage doublers are a variety of voltage multiplier circuits. Many, but not all, voltage doubler circuits can be viewed as a single stage of a higher order multiplier: cascading identical stages together achieves a greater voltage multiplication.
Voltage doubling rectifiers
Villard circuit
The Villard circuit, conceived by Paul Ulrich Villard, consists simply of a capacitor and a diode. While it has the great benefit of simplicity, its output has very poor ripple characteristics. Essentially, the circuit is a diode clamp circuit. The capacitor is charged on the negative half cycles to the peak AC voltage (Vpk). The output is the superposition of the input AC waveform and the steady DC of the capacitor. The effect of the circuit is to shift the DC value of the waveform. The negative peaks of the AC waveform are "clamped" to 0 V (actually −VF, the small forward bias voltage of the diode) by the diode, therefore the positive peaks of the output waveform are 2Vpk. The peak-to-peak ripple is an enormous 2Vpk and cannot be smoothed unless the circuit is effectively turned into one of the more sophisticated forms. This is the circuit (with diode reversed) used to supply the negative high voltage for the
Document 3:::
Majorana 1 is a hardware device developed by Microsoft, with potential applications to quantum computing. It is the first device produced by Microsoft intended for use in quantum computing. It is an indium arsenide-aluminium hybrid device that admits superconductivity at low temperatures. Microsoft claims that it shows some signals of hosting boundary Majorana zero modes. The device can fit eight qubits. Majorana zero modes, if confirmed, could have potential application to making topological qubits, and eventually a large-scale topological quantum computers.
In its February 2025 announcement, Microsoft claimed that the Majorana 1 represents progress in its long-running project to create a quantum computer based on topological qubits. The announcement has generated both excitement and skepticism within the scientific community, in the absence of definitive public evidence that the Majorana 1 device exhibits Majorana zero modes.
Background
Quantum computing research has historically faced challenges in achieving qubit stability and scalability. Traditional qubits, such as those based on superconducting circuits or trapped ions, are highly susceptible to noise and decoherence, which can introduce errors in computations. To overcome these limitations, researchers have been exploring various approaches to building more robust and fault-tolerant quantum computers. Topological qubits, first theorized in 1997 by Alexei Kitaev and Michael Freedman, offer a promising solution by encoding quantum information in a way that is inherently protected from environmental disturbances. This protection stems from the topological properties of the system, which are resistant to local perturbations. Microsoft's approach, based on Majorana fermions in semiconductor-superconductor heterostructures, is one of several efforts to realize topological quantum computing.
Controversy
Microsoft's quantum hardware has been the subject of controversy since its high-profile retracted articl
Document 4:::
In algebra and number theory, a distribution is a function on a system of finite sets into an abelian group which is analogous to an integral: it is thus the algebraic analogue of a distribution in the sense of generalised function.
The original examples of distributions occur, unnamed, as functions φ on Q/Z satisfying
Such distributions are called ordinary distributions. They also occur in p-adic integration theory in Iwasawa theory.
Let ... → Xn+1 → Xn → ... be a projective system of finite sets with surjections, indexed by the natural numbers, and let X be their projective limit. We give each Xn the discrete topology, so that X is compact. Let φ = (φn) be a family of functions on Xn taking values in an abelian group V and compatible with the projective system:
for some weight function w. The family φ is then a distribution on the projective system X.
A function f on X is "locally constant", or a "step function" if it factors through some Xn. We can define an integral of a step function against φ as
The definition extends to more general projective systems, such as those indexed by the positive integers ordered by divisibility. As an important special case consider the projective system Z/nZ indexed by positive integers ordered by divisibility. We identify this with the system (1/n)Z/Z with limit Q/Z.
For x in R we let ⟨x⟩ denote the fractional part of x normalised to 0 ≤ ⟨x⟩ < 1, and let {x} denote the fractional part normalised to 0 < {x} ≤ 1.
Examples
Hurwitz zeta function
The multiplication theorem for the Hurwitz zeta function
gives a distribution relation
Hence for given s, the map is a distribution on Q/Z.
Bernoulli distribution
Recall that the Bernoulli polynomials Bn are defined by
for n ≥ 0, where bk are the Bernoulli numbers, with generating function
They satisfy the distribution relation
Thus the map
defined by
is a distribution.
Cyclotomic units
The cyclotomic units satisfy distribution relations. Let a be an element of Q
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What was the primary cause of the Gerrards Cross Tunnel collapse as confirmed by a later investigation in 2022?
A. Heavy rainfall
B. Insufficient safety checks
C. Backfilling operation
D. Design flaws
Answer: | C. Backfilling operation |
Relavent Documents:
Document 0:::
The free surface effect is a mechanism which can cause a watercraft to become unstable and capsize.
It refers to the tendency of liquids — and of unbound aggregates of small solid objects, like seeds, gravel, or crushed ore, whose behavior approximates that of liquids — to move in response to changes in the attitude of a craft's cargo holds, decks, or liquid tanks in reaction to operator-induced motions (or sea states caused by waves and wind acting upon the craft). When referring to the free surface effect, the condition of a tank that is not full is described as a "slack tank", while a full tank is "pressed up".
Stability and equilibrium
In a normally loaded vessel any rolling from perpendicular is countered by a righting moment generated from the increased volume of water displaced by the hull on the lowered side. This assumes the center of gravity of the vessel is relatively constant. If a moving mass inside the vessel moves in the direction of the roll, this counters the righting effect by moving the center of gravity towards the lowered side. The free surface effect can become a problem in a craft with large partially full bulk cargo compartments, fuel tanks, or water tanks (especially if they span the full breadth of the ship), or from accidental flooding, such as has occurred in several accidents involving roll-on/roll-off ferries.
If a compartment or tank is either empty or full, there is no change in the craft's center of mass as it rolls from side to side (in strong winds, heavy seas, or on sharp motions or turns). However, if the compartment is only partially full, the liquid in the compartment will respond to the vessel's heave, pitch, roll, surge, sway or yaw. For example, as a vessel rolls to port, liquid will displace to the port side of a compartment, and this will move the vessel's center of mass to port. This has the effect of slowing the vessel's return to vertical.
The momentum of large volumes of moving liquids cause significant dynamic for
Document 1:::
The Truth About Crime is a British television documentary series inspired and presented by Nick Ross in association with the film-maker Roger Graef, executive producer Sam Collyns and series producer Alice Perman. It was first broadcast on BBC One in July and August 2009.
Region
The show focused on a single city, Oxford, which has demographics and crime rates broadly representative of urban Britain, and used a multitude of techniques to measure the real extent of crime and victimisation. In a two-week crime audit, camera teams followed police, fire services and paramedics and an on-line questionnaire, based closely on the national British Crime Survey, invited residents and businesspeople to describe their personal experiences of victimisation. A survey of 14- and 15-year-olds in Oxford schools was one of the biggest of its kind ever undertaken to discover how under-16s are affected by, and involved in, crime. Random children from some of the schools were then chosen to take part in the series being quizzed on crime by Ross on such topics as theft, drugs, alcohol and many other things.
Programme 1
The first programme (BBC One 9pm Tuesday 21 July 2009) looked at violent crime and revealed that almost all woundings involved victims who had been drinking or who had been assaulted by someone who was drunk, and took place close to a licensed premise.
Lack of commensuration with official statistics
Most of the seriously injured, as measured by those treated in hospital, did not report what had happened to the police. One senior physician told Nick Ross that police figures on crime are virtually "meaningless". The physician interviewed was Jonathan Shepherd, a professor of Oral and Maxillofacial Surgery at the Cardiff University Dental School. Domestic violence was shown to be a major problem, though mostly resulting only in minor injuries, and with women as perpetrators as well as men. Women were interviewed in a Women's shelter.
Crime mapping
Helmet cameras were show
Document 2:::
{{DISPLAYTITLE:Lp space}}
In mathematics, the spaces are function spaces defined using a natural generalization of the -norm for finite-dimensional vector spaces. They are sometimes called Lebesgue spaces, named after Henri Lebesgue , although according to the Bourbaki group they were first introduced by Frigyes Riesz .
spaces form an important class of Banach spaces in functional analysis, and of topological vector spaces. Because of their key role in the mathematical analysis of measure and probability spaces, Lebesgue spaces are used also in the theoretical discussion of problems in physics, statistics, economics, finance, engineering, and other disciplines.
Preliminaries
The -norm in finite dimensions
The Euclidean length of a vector in the -dimensional real vector space is given by the Euclidean norm:
The Euclidean distance between two points and is the length of the straight line between the two points. In many situations, the Euclidean distance is appropriate for capturing the actual distances in a given space. In contrast, consider taxi drivers in a grid street plan who should measure distance not in terms of the length of the straight line to their destination, but in terms of the rectilinear distance, which takes into account that streets are either orthogonal or parallel to each other. The class of -norms generalizes these two examples and has an abundance of applications in many parts of mathematics, physics, and computer science.
For a real number the -norm or -norm of is defined by
The absolute value bars can be dropped when is a rational number with an even numerator in its reduced form, and is drawn from the set of real numbers, or one of its subsets.
The Euclidean norm from above falls into this class and is the -norm, and the -norm is the norm that corresponds to the rectilinear distance.
The -norm or maximum norm (or uniform norm) is the limit of the -norms for , given by:
For all the -norms and maximum norm satisfy the properties of a "length function" (or norm), that is:
only the zero vector has zero length,
the length of the vector is positive homogeneous with respect to multiplication by a scalar (positive homogeneity), and
the length of the sum of two vectors is no larger than the sum of lengths of the vectors (triangle inequality).
Abstractly speaking, this means that together with the -norm is a normed vector space. Moreover, it turns out that this space is complete, thus making it a Banach space.
Relations between -norms
The grid distance or rectilinear distance (sometimes called the "Manhattan distance") between two points is never shorter than the length of the line segment between them (the Euclidean or "as the crow flies" distance). Formally, this means that the Euclidean norm of any vector is bounded by its 1-norm:
This fact generalizes to -norms in that the -norm of any given vector does not grow with :
For the opposite direction, the following relation between the -norm and the -norm is known:
This inequality depends on the dimension of the underlying vector space and follows directly from the Cauchy–Schwarz inequality.
In general, for vectors in where
This is a consequence of Hölder's inequality.
When
In for the formula
defines an absolutely homogeneous function for however, the resulting function does not define a norm, because it is not subadditive. On the other hand, the formula
defines a subadditive function at the cost of losing absolute homogeneity. It does define an F-norm, though, which is homogeneous of degree
Hence, the function
defines a metric. The metric space is denoted by
Although the -unit ball around the origin in this metric is "concave", the topology defined on by the metric is the usual vector space topology of hence is a locally convex topological vector space. Beyond this qualitative statement, a quantitative way to measure the lack of convexity of is to denote by the smallest constant such that the scalar multiple of the -unit ball contains the convex hull of which is equal to The fact that for fixed we have
shows that the infinite-dimensional sequence space defined below, is no longer locally convex.
When
There is one norm and another function called the "norm" (with quotation marks).
The mathematical definition of the norm was established by Banach's Theory of Linear Operations. The space of sequences has a complete metric topology provided by the F-norm on the product metric:
The -normed space is studied in functional analysis, probability theory, and harmonic analysis.
Another function was called the "norm" by David Donoho—whose quotation marks warn that this function is not a proper norm—is the number of non-zero entries of the vector Many authors abuse terminology by omitting the quotation marks. Defining the zero "norm" of is equal to
This is not a norm because it is not homogeneous. For example, scaling the vector by a positive constant does not change the "norm". Despite these defects as a mathematical norm, the non-zero counting "norm" has uses in scientific computing, information theory, and statistics–notably in compressed sensing in signal processing and computational harmonic analysis. Despite not being a norm, the associated metric, known as Hamming distance, is a valid distance, since homogeneity is not required for distances.
spaces and sequence spaces
The -norm can be extended to vectors that have an infinite number of components (sequences), which yields the space This contains as special cases:
the space of sequences whose series are absolutely convergent,
the space of square-summable sequences, which is a Hilbert space, and
the space of bounded sequences.
The space of sequences has a natural vector space structure by applying scalar addition and multiplication. Explicitly, the vector sum and the scalar action for infinite sequences of real (or complex) numbers are given by:
Define the -norm:
Here, a complication arises, namely that the series on the right is not always convergent, so for example, the sequence made up of only ones, will have an infinite -norm for The space is then defined as the set of all infinite sequences of real (or complex) numbers such that the -norm is finite.
One can check that as increases, the set grows larger. For example, the sequence
is not in but it is in for as the series
diverges for (the harmonic series), but is convergent for
One also defines the -norm using the supremum:
and the corresponding space of all bounded sequences. It turns out that
if the right-hand side is finite, or the left-hand side is infinite. Thus, we will consider spaces for
The -norm thus defined on is indeed a norm, and together with this norm is a Banach space.
General ℓp-space
In complete analogy to the preceding definition one can define the space over a general index set (and ) as
where convergence on the right means that only countably many summands are nonzero (see also Unconditional convergence).
With the norm
the space becomes a Banach space.
In the case where is finite with elements, this construction yields with the -norm defined above.
If is countably infinite, this is exactly the sequence space defined above.
For uncountable sets this is a non-separable Banach space which can be seen as the locally convex direct limit of -sequence spaces.
For the -norm is even induced by a canonical inner product called the , which means that holds for all vectors This inner product can expressed in terms of the norm by using the polarization identity.
On it can be defined by
Now consider the case Define
where for all
The index set can be turned into a measure space by giving it the discrete σ-algebra and the counting measure. Then the space is just a special case of the more general -space (defined below).
Lp spaces and Lebesgue integrals
An space may be defined as a space of measurable functions for which the -th power of the absolute value is Lebesgue integrable, where functions which agree almost everywhere are identified. More generally, let be a measure space and
When , consider the set of all measurable functions from to or whose absolute value raised to the -th power has a finite integral, or in symbols:
To define the set for recall that two functions and defined on are said to be , written , if the set is measurable and has measure zero.
Similarly, a measurable function (and its absolute value) is (or ) by a real number written , if the (necessarily) measurable set has measure zero.
The space is the set of all measurable functions that are bounded almost everywhere (by some real ) and is defined as the infimum of these bounds:
When then this is the same as the essential supremum of the absolute value of :
For example, if is a measurable function that is equal to almost everywhere then for every and thus for all
For every positive the value under of a measurable function and its absolute value are always the same (that is, for all ) and so a measurable function belongs to if and only if its absolute value does. Because of this, many formulas involving -norms are stated only for non-negative real-valued functions. Consider for example the identity which holds whenever is measurable, is real, and (here when ). The non-negativity requirement can be removed by substituting in for which gives
Note in particular that when is finite then the formula relates the -norm to the -norm.
Seminormed space of -th power integrable functions
Each set of functions forms a vector space when addition and scalar multiplication are defined pointwise.
That the sum of two -th power integrable functions and is again -th power integrable follows from
although it is also a consequence of Minkowski's inequality
which establishes that satisfies the triangle inequality for (the triangle inequality does not hold for ).
That is closed under scalar multiplication is due to being absolutely homogeneous, which means that for every scalar and every function
Absolute homogeneity, the triangle inequality, and non-negativity are the defining properties of a seminorm.
Thus is a seminorm and the set of -th power integrable functions together with the function defines a seminormed vector space. In general, the seminorm is not a norm because there might exist measurable functions that satisfy but are not equal to ( is a norm if and only if no such exists).
Zero sets of -seminorms
If is measurable and equals a.e. then for all positive
On the other hand, if is a measurable function for which there exists some such that then almost everywhere. When is finite then this follows from the case and the formula mentioned above.
Thus if is positive and is any measurable function, then if and only if almost everywhere. Since the right hand side ( a.e.) does not mention it follows that all have the same zero set (it does not depend on ). So denote this common set by
This set is a vector subspace of for every positive
Quotient vector space
Like every seminorm, the seminorm induces a norm (defined shortly) on the canonical quotient vector space of by its vector subspace
This normed quotient space is called and it is the subject of this article. We begin by defining the quotient vector space.
Given any the coset consists of all measurable functions that are equal to almost everywhere.
The set of all cosets, typically denoted by
forms a vector space with origin when vector addition and scalar multiplication are defined by and
This particular quotient vector space will be denoted by
Two cosets are equal if and only if (or equivalently, ), which happens if and only if almost everywhere; if this is the case then and are identified in the quotient space. Hence, strictly speaking consists of equivalence classes of functions.
The -norm on the quotient vector space
Given any the value of the seminorm on the coset is constant and equal to denote this unique value by so that:
This assignment defines a map, which will also be denoted by on the quotient vector space
This map is a norm on called the .
The value of a coset is independent of the particular function that was chosen to represent the coset, meaning that if is any coset then for every (since for every ).
The Lebesgue space
The normed vector space is called or the of -th power integrable functions and it is a Banach space for every (meaning that it is a complete metric space, a result that is sometimes called the [[Riesz–Fischer theorem#Completeness of Lp, 0 < p ≤ ∞|Riesz–Fischer theorem]]).
When the underlying measure space is understood then is often abbreviated or even just
Depending on the author, the subscript notation might denote either or
If the seminorm on happens to be a norm (which happens if and only if ) then the normed space will be linearly isometrically isomorphic to the normed quotient space via the canonical map (since ); in other words, they will be, up to a linear isometry, the same normed space and so they may both be called " space".
The above definitions generalize to Bochner spaces.
In general, this process cannot be reversed: there is no consistent way to define a "canonical" representative of each coset of in For however, there is a theory of lifts enabling such recovery.
Special cases
For the spaces are a special case of spaces; when are the natural numbers and is the counting measure. More generally, if one considers any set with the counting measure, the resulting space is denoted For example, is the space of all sequences indexed by the integers, and when defining the -norm on such a space, one sums over all the integers. The space where is the set with elements, is with its -norm as defined above.
Similar to spaces, is the only Hilbert space among spaces. In the complex case, the inner product on is defined by
Functions in are sometimes called square-integrable functions, quadratically integrable functions or square-summable functions, but sometimes these terms are reserved for functions that are square-integrable in some other sense, such as in the sense of a Riemann integral .
As any Hilbert space, every space is linearly isometric to a suitable where the cardinality of the set is the cardinality of an arbitrary basis for this particular
If we use complex-valued functions, the space is a commutative C*-algebra with pointwise multiplication and conjugation. For many measure spaces, including all sigma-finite ones, it is in fact a commutative von Neumann algebra. An element of defines a bounded operator on any space by multiplication.
When
If then can be defined as above, that is:
In this case, however, the -norm does not satisfy the triangle inequality and defines only a quasi-norm. The inequality valid for implies that
and so the function
is a metric on The resulting metric space is complete.
In this setting satisfies a reverse Minkowski inequality, that is for
This result may be used to prove Clarkson's inequalities, which are in turn used to establish the uniform convexity of the spaces for .
The space for is an F-space: it admits a complete translation-invariant metric with respect to which the vector space operations are continuous. It is the prototypical example of an F-space that, for most reasonable measure spaces, is not locally convex: in or every open convex set containing the function is unbounded for the -quasi-norm; therefore, the vector does not possess a fundamental system of convex neighborhoods. Specifically, this is true if the measure space contains an infinite family of disjoint measurable sets of finite positive measure.
The only nonempty convex open set in is the entire space. Consequently, there are no nonzero continuous linear functionals on the continuous dual space is the zero space. In the case of the counting measure on the natural numbers (i.e. ), the bounded linear functionals on are exactly those that are bounded on , i.e., those given by sequences in Although does contain non-trivial convex open sets, it fails to have enough of them to give a base for the topology.
Having no linear functionals is highly undesirable for the purposes of doing analysis. In case of the Lebesgue measure on rather than work with for it is common to work with the Hardy space whenever possible, as this has quite a few linear functionals: enough to distinguish points from one another. However, the Hahn–Banach theorem still fails in for .
Properties
Hölder's inequality
Suppose satisfy . If and then and
This inequality, called Hölder's inequality, is in some sense optimal since if and is a measurable function such that
where the supremum is taken over the closed unit ball of then and
Generalized Minkowski inequality
Minkowski inequality, which states that satisfies the triangle inequality, can be generalized:
If the measurable function is non-negative (where and are measure spaces) then for all
Atomic decomposition
If then every non-negative has an , meaning that there exist a sequence of non-negative real numbers and a sequence of non-negative functions called , whose supports are pairwise disjoint sets of measure such that
and for every integer
and
and where moreover, the sequence of functions depends only on (it is independent of ).
These inequalities guarantee that for all integers while the supports of being pairwise disjoint implies
An atomic decomposition can be explicitly given by first defining for every integer
and then letting
where denotes the measure of the set and denotes the indicator function of the set
The sequence is decreasing and converges to as Consequently, if then and so that is identically equal to (in particular, the division by causes no issues).
The complementary cumulative distribution function of that was used to define the also appears in the definition of the weak -norm (given below) and can be used to express the -norm (for ) of as the integral
where the integration is with respect to the usual Lebesgue measure on
Dual spaces
The dual space of for has a natural isomorphism with where is such that . This isomorphism associates with the functional defined by
for every
is a well defined continuous linear mapping which is an isometry by the extremal case of Hölder's inequality. If is a -finite measure space one can use the Radon–Nikodym theorem to show that any can be expressed this way, i.e., is an isometric isomorphism of Banach spaces. Hence, it is usual to say simply that is the continuous dual space of
For the space is reflexive. Let be as above and let be the corresponding linear isometry. Consider the map from to obtained by composing with the transpose (or adjoint) of the inverse of
This map coincides with the canonical embedding of into its bidual. Moreover, the map is onto, as composition of two onto isometries, and this proves reflexivity.
If the measure on is sigma-finite, then the dual of is isometrically isomorphic to (more precisely, the map corresponding to is an isometry from onto
The dual of is subtler. Elements of can be identified with bounded signed finitely additive measures on that are absolutely continuous with respect to See ba space for more details. If we assume the axiom of choice, this space is much bigger than except in some trivial cases. However, Saharon Shelah proved that there are relatively consistent extensions of Zermelo–Fraenkel set theory (ZF + DC + "Every subset of the real numbers has the Baire property") in which the dual of is
Embeddings
Colloquially, if then contains functions that are more locally singular, while elements of can be more spread out. Consider the Lebesgue measure on the half line A continuous function in might blow up near but must decay sufficiently fast toward infinity. On the other hand, continuous functions in need not decay at all but no blow-up is allowed. More formally:
If : if and only if does not contain sets of finite but arbitrarily large measure (e.g. any finite measure).
If : if and only if does not contain sets of non-zero but arbitrarily small measure (e.g. the counting measure).
Neither condition holds for the Lebesgue measure on the real line while both conditions holds for the counting measure on any finite set. As a consequence of the closed graph theorem, the embedding is continuous, i.e., the identity operator is a bounded linear map from to in the first case and to in the second. Indeed, if the domain has finite measure, one can make the following explicit calculation using Hölder's inequality
leading to
The constant appearing in the above inequality is optimal, in the sense that the operator norm of the identity is precisely
the case of equality being achieved exactly when -almost-everywhere.
Dense subspaces
Let and be a measure space and consider an integrable simple function on given by
where are scalars, has finite measure and is the indicator function of the set for By construction of the integral, the vector space of integrable simple functions is dense in
More can be said when is a normal topological space and its Borel –algebra.
Suppose is an open set with Then for every Borel set contained in there exist a closed set and an open set such that
for every . Subsequently, there exists a Urysohn function on that is on and on with
If can be covered by an increasing sequence of open sets that have finite measure, then the space of –integrable continuous functions is dense in More precisely, one can use bounded continuous functions that vanish outside one of the open sets
This applies in particular when and when is the Lebesgue measure. For example, the space of continuous and compactly supported functions as well as the space of integrable step functions are dense in .
Closed subspaces
If is any positive real number, is a probability measure on a measurable space (so that ), and is a vector subspace, then is a closed subspace of if and only if is finite-dimensional ( was chosen independent of ).
In this theorem, which is due to Alexander Grothendieck, it is crucial that the vector space be a subset of since it is possible to construct an infinite-dimensional closed vector subspace of (which is even a subset of ), where is Lebesgue measure on the unit circle and is the probability measure that results from dividing it by its mass
Applications
Statistics
In statistics, measures of central tendency and statistical dispersion, such as the mean, median, and standard deviation, can be defined in terms of metrics, and measures of central tendency can be characterized as solutions to variational problems.
In penalized regression, "L1 penalty" and "L2 penalty" refer to penalizing either the norm of a solution's vector of parameter values (i.e. the sum of its absolute values), or its squared norm (its Euclidean length). Techniques which use an L1 penalty, like LASSO, encourage sparse solutions (where the many parameters are zero). Elastic net regularization uses a penalty term that is a combination of the norm and the squared norm of the parameter vector.
Hausdorff–Young inequality
The Fourier transform for the real line (or, for periodic functions, see Fourier series), maps to (or to ) respectively, where and This is a consequence of the Riesz–Thorin interpolation theorem, and is made precise with the Hausdorff–Young inequality.
By contrast, if the Fourier transform does not map into
Hilbert spaces
Hilbert spaces are central to many applications, from quantum mechanics to stochastic calculus. The spaces and are both Hilbert spaces. In fact, by choosing a Hilbert basis i.e., a maximal orthonormal subset of or any Hilbert space, one sees that every Hilbert space is isometrically isomorphic to (same as above), i.e., a Hilbert space of type
Generalizations and extensions
Weak
Let be a measure space, and a measurable function with real or complex values on The distribution function of is defined for by
If is in for some with then by Markov's inequality,
A function is said to be in the space weak , or if there is a constant such that, for all
The best constant for this inequality is the -norm of and is denoted by
The weak coincide with the Lorentz spaces so this notation is also used to denote them.
The -norm is not a true norm, since the triangle inequality fails to hold. Nevertheless, for in
and in particular
In fact, one has
and raising to power and taking the supremum in one has
Under the convention that two functions are equal if they are equal almost everywhere, then the spaces are complete .
For any the expression
is comparable to the -norm. Further in the case this expression defines a norm if Hence for the weak spaces are Banach spaces .
A major result that uses the -spaces is the Marcinkiewicz interpolation theorem, which has broad applications to harmonic analysis and the study of singular integrals.
Weighted spaces
As before, consider a measure space Let be a measurable function. The -weighted space is defined as where means the measure defined by
or, in terms of the Radon–Nikodym derivative, the norm for is explicitly
As -spaces, the weighted spaces have nothing special, since is equal to But they are the natural framework for several results in harmonic analysis ; they appear for example in the Muckenhoupt theorem: for the classical Hilbert transform is defined on where denotes the unit circle and the Lebesgue measure; the (nonlinear) Hardy–Littlewood maximal operator is bounded on Muckenhoupt's theorem describes weights such that the Hilbert transform remains bounded on and the maximal operator on
spaces on manifolds
One may also define spaces on a manifold, called the intrinsic spaces of the manifold, using densities.
Vector-valued spaces
Given a measure space and a locally convex space (here assumed to be complete), it is possible to define spaces of -integrable -valued functions on in a number of ways. One way is to define the spaces of Bochner integrable and Pettis integrable functions, and then endow them with locally convex TVS-topologies that are (each in their own way) a natural generalization of the usual topology. Another way involves topological tensor products of with Element of the vector space are finite sums of simple tensors where each simple tensor may be identified with the function that sends This tensor product is then endowed with a locally convex topology that turns it into a topological tensor product, the most common of which are the projective tensor product, denoted by and the injective tensor product, denoted by In general, neither of these space are complete so their completions are constructed, which are respectively denoted by and (this is analogous to how the space of scalar-valued simple functions on when seminormed by any is not complete so a completion is constructed which, after being quotiented by is isometrically isomorphic to the Banach space ). Alexander Grothendieck showed that when is a nuclear space (a concept he introduced), then these two constructions are, respectively, canonically TVS-isomorphic with the spaces of Bochner and Pettis integral functions mentioned earlier; in short, they are indistinguishable.
space of measurable functions
The vector space of (equivalence classes of) measurable functions on is denoted . By definition, it contains all the and is equipped with the topology of convergence in measure. When is a probability measure (i.e., ), this mode of convergence is named convergence in probability. The space is always a topological abelian group but is only a topological vector space if This is because scalar multiplication is continuous if and only if If is -finite then the weaker topology of local convergence in measure is an F-space, i.e. a completely metrizable topological vector space. Moreover, this topology is isometric to global convergence in measure for a suitable choice of probability measure
The description is easier when is finite. If is a finite measure on the function admits for the convergence in measure the following fundamental system of neighborhoods
The topology can be defined by any metric of the form
where is bounded continuous concave and non-decreasing on with and when (for example, Such a metric is called Lévy-metric for Under this metric the space is complete. However, as mentioned above, scalar multiplication is continuous with respect to this metric only if . To see this, consider the Lebesgue measurable function defined by . Then clearly . The space is in general not locally bounded, and not locally convex.
For the infinite Lebesgue measure on the definition of the fundamental system of neighborhoods could be modified as follows
The resulting space , with the topology of local convergence in measure, is isomorphic to the space for any positive –integrable density
See also
Notes
References
.
.
.
.
.
.
External links
Proof that Lp spaces are complete
Document 3:::
Street reclaiming is the process of converting, or otherwise returning streets to a stronger focus on non-car use — such as walking, cycling and active street life. It is advocated by many urban planners and urban economists, of widely varying political points of view. Its primary benefits are thought to be:
Decreased automobile traffic with less noise pollution, fewer automobile accidents, reduced smog and air pollution
Greater safety and access for pedestrians and cyclists
Less frequent surface maintenance than car-driven roads
Reduced summer temperatures due to less asphalt and more green spaces
Increased pedestrian traffic which also increases social and commercial opportunities
Increased gardening space for urban residents
Better support for co-housing and infirm residents, e.g. suburban eco-villages built around former streets
Campaigns
An early example of street reclamation was the Stockholm carfree day in 1969.
Some consider the best advantages to be gained by redesigning streets, for example as shared space, while others, such as campaigns like "Reclaim the Streets", a widespread "dis-organization", run a variety of events to physically reclaim the streets for political and artistic actions, often called street parties. David Engwicht is also a strong proponent of the concept that street life, rather than physical redesign, is the primary tool of street reclamation.
See also
References
External links
RTS — Reclaim the Streets
Park(ing)
– 22 September
What if everyone had a car? by the BBC World News
Document 4:::
In organometallic chemistry, agostic interaction refers to the intramolecular interaction of a coordinatively-unsaturated transition metal with an appropriately situated C−H bond on one of its ligands. The interaction is the result of two electrons involved in the C−H bond interaction with an empty d-orbital of the transition metal, resulting in a three-center two-electron bond. It is a special case of a C–H sigma complex. Historically, agostic complexes were the first examples of C–H sigma complexes to be observed spectroscopically and crystallographically, due to intramolecular interactions being particularly favorable and more often leading to robust complexes. Many catalytic transformations involving oxidative addition and reductive elimination are proposed to proceed via intermediates featuring agostic interactions. Agostic interactions are observed throughout organometallic chemistry in alkyl, alkylidene, and polyenyl ligands.
History
The term agostic, derived from the Ancient Greek word for "to hold close to oneself", was coined by Maurice Brookhart and Malcolm Green, on the suggestion of the classicist Jasper Griffin, to describe this and many other interactions between a transition metal and a C−H bond. Often such agostic interactions involve alkyl or aryl groups that are held close to the metal center through an additional σ-bond.
Short interactions between hydrocarbon substituents and coordinatively unsaturated metal complexes have been noted since the 1960s. For example, in tris(triphenylphosphine) ruthenium dichloride, a short interaction is observed between the ruthenium(II) center and a hydrogen atom on the ortho position of one of the nine phenyl rings. Complexes of borohydride are described as using the three-center two-electron bonding model.
The nature of the interaction was foreshadowed in main group chemistry in the structural chemistry of trimethylaluminium.
Characteristics of agostic bonds
Agostic interactions are best demonstrated
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the significance of Lp spaces in mathematics and other disciplines according to the text?
A. They are only useful in abstract mathematics.
B. They are crucial for mathematical analysis and have applications in physics, statistics, and finance.
C. They are primarily concerned with the geometric properties of shapes.
D. They are only relevant in the study of finite-dimensional vector spaces.
Answer: | B. They are crucial for mathematical analysis and have applications in physics, statistics, and finance. |
Relavent Documents:
Document 0:::
In electrochemistry, CO stripping is a special process of voltammetry where a monolayer of carbon monoxide already adsorbed on the surface of an electrocatalyst is electrochemically oxidized and thus removed from the surface. A well-known process of this type is CO stripping on Pt/C electrocatalysts in which the electrooxidation peak occurs somewhere between 0.5 and 0.9 V depending on the characteristics and structural properties of the specimen.
Principle
Some metals, such as platinum, readily adsorb carbon monoxide, which is usually undesirable as it results in catalyst poisoning.
However, the strong affinity of CO to such catalysts also presents an opportunity: since carbon monoxide is a small molecule with a strong affinity to the catalyst, a large enough amount of CO will adsorb to the entire available surface area of the catalyst. That, in turn, means that by evaluating the amount of CO adsorbed, the catalyst's available surface area can be indirectly measured.
That surface area - also known as "real surface area" or "electrochemically active surface area" - can be measured by electrochemically oxidizing the adsorbed carbon monoxide, as the charge expended in oxidizing CO is directly proportional to the amount of CO adsorbed on the surface and therefore, the surface area of the catalyst.
Usage
CO stripping is one of the methods used to determine the electrochemically active surface area of electrodes and catalysts that irreversibly adsorb carbon monoxide, most notably ones containing platinum and other transition metals.
Document 1:::
In quantum mechanics, the Schrödinger equation describes how a system changes with time. It does this by relating changes in the state of the system to the energy in the system (given by an operator called the Hamiltonian). Therefore, once the Hamiltonian is known, the time dynamics are in principle known. All that remains is to plug the Hamiltonian into the Schrödinger equation and solve for the system state as a function of time.
Often, however, the Schrödinger equation is difficult to solve (even with a computer). Therefore, physicists have developed mathematical techniques to simplify these problems and clarify what is happening physically. One such technique is to apply a unitary transformation to the Hamiltonian. Doing so can result in a simplified version of the Schrödinger equation which nonetheless has the same solution as the original.
Transformation
A unitary transformation (or frame change) can be expressed in terms of a time-dependent Hamiltonian and unitary operator . Under this change, the Hamiltonian transforms as:
.
The Schrödinger equation applies to the new Hamiltonian. Solutions to the untransformed and transformed equations are also related by . Specifically, if the wave function satisfies the original equation, then will satisfy the new equation.
Derivation
Recall that by the definition of a unitary matrix, . Beginning with the Schrödinger equation,
,
we can therefore insert the identity at will. In particular, inserting it after and also premultiplying both sides by , we get
.
Next, note that by the product rule,
.
Inserting another and rearranging, we get
.
Finally, combining (1) and (2) above results in the desired transformation:
.
If we adopt the notation to describe the transformed wave function, the equations can be written in a clearer form. For instance, can be rewritten as
,
which can be rewritten in the form of the original Schrödinger equation,
The original wave function can be recovered as .
Relation to
Document 2:::
Ogataea is a genus of ascomycetous yeasts in the family Saccharomycetaceae. It was separated from the former genus Hansenula via an examination of their 18S and 26S rRNA partial base sequencings by Yamada et al. 1994.
The genus name of Ogataea is in honour of Koichi Ogata (x - 1977), who was a Japanese microbiologist from the Department of Agricultural Chemistry, Faculty of Agriculture, at Kyoto University. It was stated in the journal; "The genus is named in honor of the late Professor Dr. Koichi Ogata, Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Kyoto, Japan, in recognition of his studies on the oxidation and assimilation of methanol (C1 compound) in methanol-utilizing yeasts."
The genus was circumscribed by Yuzo Yamada, Kojiro Maeda and Kozaburo Mikata in Biosc., Biotechn. Biochem. vol.58 (Issue 7) on page 1253 in 1994.
Diagnosis
Like other yeasts, also the species within the genus Ogataea are single-celled or build pseudohyphae of only a few elongated cells; true hyphae are not formed.
They are able to reproduce sexually or asexually. The latter case happens with a cell division by multilateral budding on a narrow base with spherical to ellipsoidal budded cells. In the sexual reproduction the asci are deliquescent and may be unconjugated or show conjugation between a cell and its bud or between independent cells. Asci produce one to four, sometimes more, ascospores which are hat-shaped, allantoid or spherical with a ledge. The species are homothallic or infrequently heterothallic.
Ogataea cells are able to ferment glucose or other sugars and some species assimilate nitrate. All known species are able to utilize methanol as carbon source. The predominant ubiquinone is coenzyme Q-7 and the diazonium blue B test is negative. Some species are used and cultured for microbiological and genetic research e.g. Ogataea polymorpha, Ogataea minuta or Ogataea methanolica. Ogataea minuta (Wickerham) Y. Yamada, K. Maeda & Mikata is th
Document 3:::
An explosimeter is a gas detector which is used to measure the amount of combustible gases present in a sample. When a percentage of the lower explosive limit (LEL) of an atmosphere is exceeded, an alarm signal on the instrument is activated.
The device, also called a combustible gas detector, operates on the principle of resistance proportional to heat—a wire is heated, and a sample of the gas is introduced to the hot wire. Combustible gases burn in the presence of the hot wire, thus increasing the resistance and disturbing a Wheatstone bridge, which gives the reading. A flashback arrestor is installed in the device to avoid the explosimeter igniting the sample external to the device.
Note, that the detection readings of an explosimeter are only accurate if the gas being sampled has the same characteristics and response as the calibration gas. Most explosimeters are calibrated to methane, hydrogen, and carbon monoxide.
Explosimeters are important because workspaces may contain a flammable or explosive atmosphere due to the accumulation of flammable gases or vapors. Sparks from ordinary battery-powered portable equipment, including cameras, cell phones, laptop computers, or anything else located on the job site may serve as an ignition source. The explosimeter warns the user of dangerous atmospheric conditions before a possible explosion can occur.
Explosimetry
Explosimetry simply means the measurement of flammable or explosive conditions, normally in the atmosphere around us. In modern times, jobsites both above ground and below ground can have a wide range of dangerous flammable materials present. The danger of these flammable materials are mitigated by detection systems. Explosimetry sensors are integrated into stationary and portable devices to detect the concentration of the calibrated gas in air. The explosimeter is an example of a detection system with an explosimetry sensor in it.
For explosimeters to work properly they must be calibrated for a parti
Document 4:::
The Chicago Lake Tunnel was the first of several tunnels built from the city of Chicago's shore on Lake Michigan two miles out into the lake to access unpolluted fresh water far from the city's sewage.
Waterborne disease in early Chicago
In the early decades of its existence, the growing city was only about three feet above the surface of Lake Michigan, and the areas of early European settlement were flat and sandy with a high water table. European settlers in Chicago only needed to dig 6 to 12 feet to create a private well. The same settlers, however, would also dig privy vaults for human waste nearby. Because the sandy soil topped a layer of hard clay, human waste would sink from the outhouse, meet the impervious clay, and travel laterally into the freshwater supply. As a result, Chicago suffered numerous widespread outbreaks of waterborne diseases. The Chicago Board of Health was organized in 1835, in response to the threat of a cholera epidemic, and later outbreaks of cholera in 1852 and 1854 killed thousands.
Chesbrough's Water Plan
In 1855 the city’s newly formed Board of Sewerage Commissioners hired the 42-year-old Ellis S. Chesbrough (1813–1886), the first city engineer of Boston to study the problem. In 1863, Chesbrough completed a design for a water and sewer system for the city that included a tunnel five feet wide and lined with brick that would extend through the clay bed of Lake Michigan to a distance of 10,567 feet. Work started in 1864 and the tunnel was opened in 1867.
Construction
Gravity forces water into the tunnel through a structure called a crib. The crib for the Lake Tunnel was forty feet high and had five sides. Each side was fifty-eight feet long. The crib had outer, middle, inner walls bolted together, and each was sealed with caulk and tar in the same way ships of the day were made. The crib comprised fifteen separate water-tight compartments with an opening at the bottom twenty-five feet in diameter referred to as "the well," which d
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What was the primary goal of the Brotherhood in "The Invisible Empire"?
A. To create a new world religion
B. To gain control over the entire world
C. To protect the innocent from evil
D. To develop advanced technology for peace
Answer: | B. To gain control over the entire world |
Relavent Documents:
Document 0:::
Plants may reproduce sexually or asexually. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Vegetative reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur. In asexual reproduction, only one parent is involved.
Asexual reproduction
Asexual reproduction does not involve the production and fusion of male and female gametes. Asexual reproduction may occur through budding, fragmentation, spore formation, regeneration and vegetative propagation.
Asexual reproduction is a type of reproduction where the offspring comes from one parent only, thus inheriting the characteristics of the parent. Asexual reproduction in plants occurs in two fundamental forms, vegetative reproduction and agamospermy. Vegetative reproduction involves a vegetative piece of the original plant producing new individuals by budding, tillering, etc. and is distinguished from apomixis, which is a replacement of sexual reproduction, and in some cases involves seeds. Apomixis occurs in many plant species such as dandelions (Taraxacum species) and also in some non-plant organisms. For apomixis and similar processes in non-plant organisms, see parthenogenesis.
Natural vegetative reproduction is a process mostly found in perennial plants, and typically involves structural modifications of the stem or roots and in a few species leaves. Most plant species that employ vegetative reproduction do so as a means to perennialize the plants, allowing them to survive from one season to the next and often facilitating their expansion in size. A plant that persists in a location through vegetative reproduction of individuals gives rise to a clonal colony. A single ramet, or apparent individual, of a clonal colony is genetically identical to all others in the same colony. The distance that a plant can move during vegetative reproduction is limited, though some plants can produce ramets from branching rhizomes or stolons that cover a wide area, often in only a few growing seasons. In a sense, this process is not one of reproduction but one of survival and expansion of biomass of the individual. When an individual organism increases in size via cell multiplication and remains intact, the process is called vegetative growth. However, in vegetative reproduction, the new plants that result are new individuals in almost every respect except genetic. A major disadvantage of vegetative reproduction is the transmission of pathogens from parent to offspring. It is uncommon for pathogens to be transmitted from the plant to its seeds (in sexual reproduction or in apomixis), though there are occasions when it occurs.
Seeds generated by apomixis are a means of asexual reproduction, involving the formation and dispersal of seeds that do not originate from the fertilization of the embryos. Hawkweeds (Hieracium), dandelions (Taraxacum), some species of Citrus and Kentucky blue grass (Poa pratensis) all use this form of asexual reproduction. Pseudogamy occurs in some plants that have apomictic seeds, where pollination is often needed to initiate embryo growth, though the pollen contributes no genetic material to the developing offspring. Other forms of apomixis occur in plants also, including the generation of a plantlet in replacement of a seed or the generation of bulbils instead of flowers, where new cloned individuals are produced.
Structures
A rhizome is a modified underground stem serving as an organ of vegetative reproduction; the growing tips of the rhizome can separate as new plants, e.g., polypody, iris, couch grass and nettles.
Prostrate aerial stems, called runners or stolons, are important vegetative reproduction organs in some species, such as the strawberry, numerous grasses, and some ferns.
Adventitious buds form on roots near the ground surface, on damaged stems (as on the stumps of cut trees), or on old roots. These develop into above-ground stems and leaves. A form of budding called suckering is the reproduction or regeneration of a plant by shoots that arise from an existing root system. Species that characteristically produce suckers include elm (Ulmus) and many members of the rose family such as Rosa, Kerria and Rubus.
Bulbous plants such as onion (Allium cepa), hyacinths, narcissi and tulips reproduce vegetatively by dividing their underground bulbs into more bulbs. Other plants like potatoes (Solanum tuberosum) and dahlias reproduce vegetatively from underground tubers. Gladioli and crocuses reproduce vegetatively in a similar way with corms.
Gemmae are single cells or masses of cells that detach from plants to form new clonal individuals. These are common in Liverworts and mosses and in the gametophyte generation of some filmy fern. They are also present in some Club mosses such as Huperzia lucidula . They are also found in some higher plants such as species of Drosera.
Usage
The most common form of plant reproduction used by people is seeds, but a number of asexual methods are used which are usually enhancements of natural processes, including: cutting, grafting, budding, layering, division, sectioning of rhizomes, roots, tubers, bulbs, stolons, tillers, etc., and artificial propagation by laboratory tissue cloning. Asexual methods are most often used to propagate cultivars with individual desirable characteristics that do not come true from seed. Fruit tree propagation is frequently performed by budding or grafting desirable cultivars (clones), onto rootstocks that are also clones, propagated by stooling.
In horticulture, a cutting is a branch that has been cut off from a mother plant below an internode and then rooted, often with the help of a rooting liquid or powder containing hormones. When a full root has formed and leaves begin to sprout anew, the clone is a self-sufficient plant, genetically identical.
Examples include cuttings from the stems of blackberries (Rubus occidentalis), African violets (Saintpaulia), verbenas (Verbena) to produce new plants. A related use of cuttings is grafting, where a stem or bud is joined onto a different stem. Nurseries offer for sale trees with grafted stems that can produce four or more varieties of related fruits, including apples. The most common usage of grafting is the propagation of cultivars onto already rooted plants, sometimes the rootstock is used to dwarf the plants or protect them from root damaging pathogens.
Since vegetatively propagated plants are clones, they are important tools in plant research. When a clone is grown in various conditions, differences in growth can be ascribed to environmental effects instead of genetic differences.
Sexual reproduction
Sexual reproduction involves two fundamental processes: meiosis, which rearranges the genes and reduces the number of chromosomes, and fertilization, which restores the chromosome to a complete diploid number. In between these two processes, different types of plants and algae vary, but many of them, including all land plants, undergo alternation of generations, with two different multicellular structures (phases), a gametophyte and a sporophyte. The evolutionary origin and adaptive significance of sexual reproduction are discussed in the pages Evolution of sexual reproduction and Origin and function of meiosis.
The gametophyte is the multicellular structure (plant) that is haploid, containing a single set of chromosomes in each cell. The gametophyte produces male or female gametes (or both), by a process of cell division, called mitosis. In vascular plants with separate gametophytes, female gametophytes are known as mega gametophytes (mega=large, they produce the large egg cells) and the male gametophytes are called micro gametophytes (micro=small, they produce the small sperm cells).
The fusion of male and female gametes (fertilization) produces a diploid zygote, which develops by mitotic cell divisions into a multicellular sporophyte.
The mature sporophyte produces spores by meiosis, sometimes referred to as reduction division because the chromosome pairs are separated once again to form single sets.
In mosses and liverworts, the gametophyte is relatively large, and the sporophyte is a much smaller structure that is never separated from the gametophyte. In ferns, gymnosperms, and flowering plants (angiosperms), the gametophytes are relatively small and the sporophyte is much larger. In gymnosperms and flowering plants the megagametophyte is contained within the ovule (that may develop into a seed) and the microgametophyte is contained within a pollen grain.
History of sexual reproduction of plants
Unlike animals, plants are immobile, and cannot seek out sexual partners for reproduction. In the evolution of early plants, abiotic means, including water and much later, wind, transported sperm for reproduction. The first plants were aquatic, as described in the page Evolutionary history of plants, and released sperm freely into the water to be carried with the currents. Primitive land plants such as liverworts and mosses had motile sperm that swam in a thin film of water or were splashed in water droplets from the male reproduction organs onto the female organs. As taller and more complex plants evolved, modifications in the alternation of generations evolved. In the Paleozoic era progymnosperms reproduced by using spores dispersed on the wind. The seed plants including seed ferns, conifers and cordaites, which were all gymnosperms, evolved about 350 million years ago. They had pollen grains that contained the male gametes for protection of the sperm during the process of transfer from the male to female parts.
It is believed that insects fed on the pollen, and plants thus evolved to use insects to actively carry pollen from one plant to the next. Seed producing plants, which include the angiosperms and the gymnosperms, have a heteromorphic alternation of generations with large sporophytes containing much-reduced gametophytes. Angiosperms have distinctive reproductive organs called flowers, with carpels, and the female gametophyte is greatly reduced to a female embryo sac, with as few as eight cells. Each pollen grains contains a greatly reduced male gametophyte consisting of three or four cells. The sperm of seed plants are non-motile, except for two older groups of plants, the Cycadophyta and the Ginkgophyta, which have flagella.
Flowering plants
Flowering plants, the dominant plant group, reproduce both by sexual and asexual means. Their distinguishing feature is that their reproductive organs are contained in flowers. Sexual reproduction in flowering plants involves the production of separate male and female gametophytes that produce gametes.
The anther produces pollen grains that contain male gametophytes. The pollen grains attach to the stigma on top of a carpel, in which the female gametophytes (inside ovules) are located. Plants may either self-pollinate or cross-pollinate. The transfer of pollen (the male gametophytes) to the female stigmas occurs is called pollination. After pollination occurs, the pollen grain germinates to form a pollen tube that grows through the carpel's style and transports male nuclei to the ovule to fertilize the egg cell and central cell within the female gametophyte in a process termed double fertilization. The resulting zygote develops into an embryo, while the triploid endosperm (one sperm cell plus a binucleate female cell) and female tissues of the ovule give rise to the surrounding tissues in the developing seed. The fertilized ovules develop into seeds within a fruit formed from the ovary. When the seeds are ripe they may be dispersed together with the fruit or freed from it by various means to germinate and grow into the next generation.
Pollination
Plants that use insects or other animals to move pollen from one flower to the next have developed greatly modified flower parts to attract pollinators and to facilitate the movement of pollen from one flower to the insect and from the insect to the next flower. Flowers of wind-pollinated plants tend to lack petals and or sepals; typically large amounts of pollen are produced and pollination often occurs early in the growing season before leaves can interfere with the dispersal of the pollen. Many trees and all grasses and sedges are wind-pollinated.
Plants have a number of different means to attract pollinators including color, scent, heat, nectar glands, edible pollen and flower shape. Along with modifications involving the above structures two other conditions play a very important role in the sexual reproduction of flowering plants, the first is the timing of flowering and the other is the size or number of flowers produced. Often plant species have a few large, very showy flowers while others produce many small flowers, often flowers are collected together into large inflorescences to maximize their visual effect, becoming more noticeable to passing pollinators. Flowers are attraction strategies and sexual expressions are functional strategies used to produce the next generation of plants, with pollinators and plants having co-evolved, often to some extraordinary degrees, very often rendering mutual benefit.
The largest family of flowering plants is the orchids (Orchidaceae), estimated by some specialists to include up to 35,000 species, which often have highly specialized flowers that attract particular insects for pollination. The stamens are modified to produce pollen in clusters called pollinia, which become attached to insects that crawl into the flower. The flower shapes may force insects to pass by the pollen, which is "glued" to the insect. Some orchids are even more highly specialized, with flower shapes that mimic the shape of insects to attract them to attempt to 'mate' with the flowers, a few even have scents that mimic insect pheromones.
Another large group of flowering plants is the Asteraceae or sunflower family with close to 22,000 species, which also have highly modified inflorescences composed of many individual flowers called florets. Heads with florets of one sex, when the flowers are pistillate or functionally staminate or made up of all bisexual florets, are called homogamous and can include discoid and liguliflorous type heads. Some radiate heads may be homogamous too. Plants with heads that have florets of two or more sexual forms are called heterogamous and include radiate and disciform head forms.
Ferns
Ferns typically produce large diploids with stem, roots, and leaves. On fertile leaves sporangia are produced, grouped together in sori and often protected by an indusium. If the spores are deposited onto a suitable moist substrate they germinate to produce short, thin, free-living gametophytes called prothalli that are typically heart-shaped, small and green in color. The gametophytes produce both motile sperm in the antheridia and egg cells in separate archegonia. After rains or when dew deposits a film of water, the motile sperm are splashed away from the antheridia, which are normally produced on the top side of the thallus, and swim in the film of water to the antheridia where they fertilize the egg. To promote out crossing or cross-fertilization the sperm is released before the eggs are receptive of the sperm, making it more likely that the sperm will fertilize the eggs of the different thallus. A zygote is formed after fertilization, which grows into a new sporophytic plant. The condition of having separate sporophyte and gametophyte plants is called alternation of generations. Other plants with similar reproductive strategies include Psilotum, Lycopodium, Selaginella and Equisetum.
Bryophytes
The bryophytes, which include liverworts, hornworts and mosses, can reproduce both sexually and vegetatively. The life cycles of these plants start with haploid spores that grow into the dominant form, which is a multicellular haploid gametophyte, with thalloid or leaf-like structures that photosynthesize. The gametophyte is the most commonly known phase of the plant. Bryophytes are typically small plants that grow in moist locations and like ferns, have motile sperm which swim to the ovule using flagella and therefore need water to facilitate sexual reproduction. Bryophytes show considerable variation in their reproductive structures, and a basic outline is as follows: Haploid gametes are produced in antheridia and archegonia by mitosis. The sperm released from the antheridia respond to chemicals released by ripe archegonia and swim to them in a film of water and fertilize the egg cells, thus producing zygotes that are diploid. The zygote divides repeatedly by mitotic division and grows into a diploid sporophyte. The resulting multicellular diploid sporophyte produces spore capsules called sporangia. The spores are produced by meiosis, and when ripe, the capsules burst open to release the spores. In some species each gametophyte is one sex while other species may be monoicous, producing both antheridia and archegonia on the same gametophyte which is thus hermaphrodite.
Algae
Sexual reproduction in the multicellular facultatively sexual green alga Volvox carteri is induced by oxidative stress. A two-fold increase in cellular reactive oxygen species (associated with oxidative stress) activates the V. carteri genes needed for sexual reproduction. Exposure to antioxidants inhibits the induction of sex in V. carteri. It was proposed on the basis of these observations that sexual reproduction emerged in V. carteri evolution as an adaptive response to oxidative stress and the DNA damage induced by reactive oxygen species. Oxidative stress induced DNA damage may be repaired during the meiotic event associated with germination of the zygospore and the start of a new generation.
Dispersal and offspring care
One of the outcomes of plant reproduction is the generation of seeds, spores, and fruits that allow plants to move to new locations or new habitats.
Plants do not have nervous systems or any will for their actions. Even so, scientists are able to observe mechanisms that help their offspring thrive as they grow. All organisms have mechanisms to increase survival in offspring.
Offspring care is observed in the Mammillaria hernandezii, a small cactus found in Mexico. A cactus is a type of succulent, meaning it retains water when it is available for future droughts. M. hernandezii also stores a portion of its seeds in its stem, and releases the rest to grow. This can be advantageous for many reasons. By delaying the release of some of its seeds, the cactus can protect these from potential threats from insects, herbivores, or mold caused by micro-organisms. A study found that the presence of adequate water in the environment causes M. Hernandezii to release more seeds to allow for germination. The plant was able to perceive a water potential gradient in the surroundings, and act by giving its seeds a better chance in this preferable environment. This evolutionary strategy gives a better potential outcome for seed germination.
External links
Simple Video Tutorial on Reproduction in Plant
Document 1:::
This is a list of simultaneous localization and mapping (SLAM) methods. The KITTI Vision Benchmark Suite website has a more comprehensive list of Visual SLAM methods.
List of methods
EKF SLAM
FastSLAM 1.0
FastSLAM 2.0
L-SLAM (Matlab code)
QSLAM
GraphSLAM
Occupancy Grid SLAM
DP-SLAM
Parallel Tracking and Mapping (PTAM)
LSD-SLAM (available as open-source)
S-PTAM (available as open-source)
ORB-SLAM (available as open-source)
ORB-SLAM2 (available as open-source)
ORB-SLAM3 (available as open-source)
OrthoSLAM
MonoSLAM
GroundSLAM
CoSLAM
SeqSlam
iSAM (Incremental Smoothing and Mapping)
CT-SLAM (Continuous Time) - referred to as Zebedee (SLAM)
RGB-D SLAM
BranoSLAM
Kimera (open-source)
Wildcat-SLAM
References
Document 2:::
Repeated implantation failure (RIF) is the repeated failure of the embryo to implant onto the side of the uterus wall following IVF treatment. Implantation happens at 6–7 days after conception and involves the embedding of the growing embryo into the mothers uterus and a connection being formed. A successful implantation can be determined by using an ultrasound to view the sac which the baby grows in, inside the uterus.
However, the exact definition of RIF is debated. Recently the most commonly accepted definition is when a woman under 40 has gone through three unsuccessful cycles of IVF, when in each cycle four good quality eggs have been transferred.
Repeated implantation failure should not be confused with recurrent IVF failure. Recurrent IVF failure is a much more broad term and includes all repeated failures to get pregnant from IVF. Repeated implantation failure specifically refers to those failures due to unsuccessful implanting to the uterus wall.
An unsuccessful implantation can result from problems with the mother or with the embryo. It is essential that the mother and embryo are able to communicate with each other during all stages of pregnancy, and an absence of this communication can lead to an unsuccessful implantation and a further unsuccessful pregnancy.
Contributing maternal factors
During implantation, the embryo must cross the epithelial layer of the maternal endometrium before invading and implanting in the stroma layer. Maternal factors, including congenital uterine abnormalities, fibroids, endometrial polyps, intrauterine adhesions, adenomyosis, thrombophilia and endometriosis, can reduce the chances of implantation and result in RIF.
Congenital uterine abnormalities
Congenital uterine abnormalities are irregularities in the uterus which occur during the mothers foetal development.
Hox genes
Two Hox genes have been identified to assist in the development and receptivity of the uterus and endometrium, Hoxa10 and Hoxa11. Hoxa10 has been s
Document 3:::
The Debus–Radziszewski imidazole synthesis is a multi-component reaction used for the synthesis of imidazoles from a 1,2-dicarbonyl, an aldehyde, and ammonia or a primary amine. The method is used commercially to produce several imidazoles. The process is an example of a multicomponent reaction.
The reaction can be viewed as occurring in two stages. In the first stage, the dicarbonyl and two ammonia molecules condense with the two carbonyl groups to give a diimine:
In the second stage, this diimine condenses with the aldehyde:
However, the actual reaction mechanism is not certain.
This reaction is named after Heinrich Debus and .
A modification of this general method, where one equivalent of ammonia is replaced by an amine, affords N-substituted imidazoles in good yields.
This reaction has been applied to the synthesis of a range of 1,3-dialkylimidazolium ionic liquids by using various readily available alkylamines.
References
Document 4:::
Heteroduplex analysis (HDA) is a method in biochemistry used to detect point mutations in DNA (Deoxyribonucleic acid) since 1992. Heteroduplexes are dsDNA molecules that have one or more mismatched pairs, on the other hand homoduplexes are dsDNA which are perfectly paired. This method of analysis depend up on the fact that heteroduplexes shows reduced mobility relative to the homoduplex DNA. heteroduplexes are formed between different DNA alleles. In a mixture of wild-type and mutant amplified DNA, heteroduplexes are formed in mutant alleles and homoduplexes are formed in wild-type alleles. There are two types of heteroduplexes based on type and extent of mutation in the DNA. Small deletions or insertion create bulge-type heteroduplexes which is stable and is verified by electron microscope. Single base substitutions creates more unstable heteroduplexes called bubble-type heteroduplexes, because of low stability it is difficult to visualize in electron microscopy. HDA is widely used for rapid screening of mutation of the 3 bp p.F508del deletion in the CFTR gene.
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the main disadvantage of vegetative reproduction in plants?
A. It requires two parents for offspring.
B. It limits genetic diversity among offspring.
C. It is not effective for perennial plants.
D. It does not allow for the use of seeds.
Answer: | B. It limits genetic diversity among offspring. |
Relavent Documents:
Document 0:::
Erich Otto Engel (29 September 1866, in Alt-Malisch Frankfurt – 11 February 1944, in Dachau) was a German entomologist, who specialised in Diptera.
He was a graphic artist and administrator of the Diptera collection in Zoologische Staatssammlung München.
Selected works
Engel, E. O. (1925) Neue paläarktische Asiliden (Dipt.). Konowia. 4, 189-194.
Engel, E. O., & Cuthbertson A. (1934) Systematic and biological notes on some Asilidae of Southern Rhodesia with a description of a species new to science. Proceedings of the Rhodesia Scientific Association. 34,
Engel, E.O. 1930. Asilidae (Part 24), in E. Lindner (ed.) Die Fliegen der Paläarktischen Region, vol. 4. Schweizerbart'sche, Stuttgart. 491 pp.
Engel, E.O. 1938-1954 Empididae. in Lindner, E. (Ed.). Die Fliegen der Paläarktischen Region, vol.4, 28, 1-400.
Engel, E. O., & Cuthbertson A. (1939). Systematic and biological notes on some brachycerous Diptera of southern Rhodesia. Journal of the Entomological Society of Southern Africa. 2, 181–185.
References
Anonym 1936: [Engel, E. O.] Insektenbörse, Stuttgart 53 (37)
Horn, W. 1936: [Engel, E. O.] Arb. morph. taxon. Ent. Berlin-Dahlem, Berlin 3 (4) 301*
Reiss, F. 1992: Die Sektion Diptera der Zoologischen Staatssammlung München. Spixiana Suppl., München 17 : 72-82, 9 Abb. 72-75, Portrait
External links
DEI Portrait
Document 1:::
In mathematics, the Browder–Minty theorem (sometimes called the Minty–Browder theorem) states that a bounded, continuous, coercive and monotone function T from a real, separable reflexive Banach space X into its continuous dual space X∗ is automatically surjective. That is, for each continuous linear functional g ∈ X∗, there exists a solution u ∈ X of the equation T(u) = g. (Note that T itself is not required to be a linear map.)
The theorem is named in honor of Felix Browder and George J. Minty, who independently proved it.
See also
Pseudo-monotone operator; pseudo-monotone operators obey a near-exact analogue of the Browder–Minty theorem.
References
(Theorem 10.49)
Document 2:::
Alcohol is generally disallowed in spaceflight, but space agencies have previously allowed its consumption. NASA has been stricter about alcohol consumption than the Roscosmos, both according to regulations and in practice. Astronauts and cosmonauts are restricted from being intoxicated at launch. Despite restrictions on consumption, there have been experiments in making and keeping alcoholic drinks in space.
The effects of alcohol on human physiology in microgravity have not been researched, though because medications can differ in their effects NASA expects that the effects of alcohol will also differ. Beer and other carbonated drinks are not suitable for spaceflight as the bubbles cause "wet burps"; also, a foamy head cannot form as the bubbles do not rise.
United States
On July 20, 1969, Apollo 11 astronaut Buzz Aldrin drank some wine when he took communion while on the Moon in the Lunar Module Eagle. The ceremony was not broadcast following earlier protests against religious activity that opponents believed to breach the separation between church and state.
In the 1970s, NASA's Charles Bourland planned to send sherry with the astronauts visiting Skylab, but the idea was scrapped because the smell was found to induce a gag reflex in zero-gravity flight tests, there was ambivalence among the astronauts, and angry letters were received after plans were discussed in public by Gerry Carr. Alcohol is prohibited aboard the International Space Station due to the impact it can have on the Environmental Control and Life Support System (ECLSS).
A 1985 NASA report on extended spaceflight predicted that alcohol would be missed, but would only become common in stable settlements.
Russia
The Russian state media Russia Beyond says drinking has been officially banned, but the first alcoholic drink sent into space by cosmonauts was a bottle of cognac, to the Salyut 7 in 1984. Cosmonaut Igor Volk said they would lose weight and hide alcohol in their spacesuits or hide bott
Document 3:::
Introduced by Martin Hellman and Susan K. Langford in 1994, the differential-linear attack is a mix of both linear cryptanalysis and differential cryptanalysis.
The attack utilises a differential characteristic over part of the cipher with a probability of 1 (for a few rounds—this probability would be much lower for the whole cipher). The rounds immediately following the differential characteristic have a linear approximation defined, and we expect that for each chosen plaintext pair, the probability of the linear approximation holding for one chosen plaintext but not the other will be lower for the correct key. Hellman and Langford have shown that this attack can recover 10 key bits of an 8-round DES with only 512 chosen plaintexts and an 80% chance of success.
The attack was generalised by Eli Biham et al. to use differential characteristics with probability less than 1. Besides DES, it has been applied to FEAL, IDEA, Serpent, Camellia, and even the stream cipher Phelix.
References
Document 4:::
Sir Richard Spencer (1593 − 1 November 1661) was an English nobleman, gentleman, knight, and politician who sat in the House of Commons from 1621 to 1629 and in 1661. He supported the Royalist cause in the English Civil War.
Early life
Spencer was the son of Robert Spencer, 1st Baron Spencer of Wormleighton and his wife Margaret, daughter of Sir Francis Willoughby and Elizabeth Lyttelton. He was baptised on 21 October 1593. He was educated at Corpus Christi College, Oxford in 1609 and was awarded BA in 1612. His brothers were Sir Edward Spencer, Sir John Spencer, and William Spencer, 2nd Baron Spencer of Wormleighton.
Parliamentary career
In 1621, Spencer was selected Member of Parliament for Northampton. He was a student of Gray's Inn in 1624. In 1624 and 1625 he was re-elected MP for Northampton. He became a gentleman of the bedchamber in 1626. He was re-elected MP for Northampton in 1626 and 1628 and sat until 1629 when King Charles decided to rule without parliament for eleven years.
Post-parliament actions
He was a J.P. for Kent by 1636. Spencer stood for parliament for Kent for the Long Parliament in November 1640, but withdrew before the election took place. He was imprisoned twice by the Long Parliament for promoting the moderate Kentish petition of 1642. He was a commissioner of array for the King in 1642, stood security for loans amounting to £60,000 and helped to raise two regiments of horse, which he commanded at the Battle of Edgehill. He gave up his command in 1643 and was claimed the benefit of the Oxford Articles. He settled £40 a year on the minister of Orpington and was allowed to compound for a mere £300.
However he became involved in the canal schemes of William Sandys and his financial condition became precarious. In 1651 he obtained a pass to France for himself and his family and settled in Brussels. He returned to England in about 1653 and was imprisoned and forced to pay off his debts.
At the Restoration, Spencer petitioned unsucce
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is one of the primary advantages of using the Schmidt–Kalman filter over increasing the dimensionality of the state space?
A. Improved accuracy in bias estimation
B. Reduction in computational complexity
C. Enhanced ability to observe residual biases
D. Simplicity in linear state transition models
Answer: | B. Reduction in computational complexity |
Relavent Documents:
Document 0:::
James Wood (14 December 1760 – 23 April 1839) was a mathematician, and Master of St John's College, Cambridge. In his later years he was Dean of Ely.
Life
Wood was born in Holcombe, Bury where his father ran an evening school and taught his son the elements of arithmetic and algebra. From Bury Grammar School he proceeded to St John's College, Cambridge in 1778, graduating as senior wrangler in 1782. On graduating he became a fellow of the college and in his long tenure there produced several successful academic textbooks for students of mathematics. Between 1795 and 1799 his The principles of mathematics and natural philosophy, was printed, in four volumes, by J. Burges. Vol.I: 'The elements of algebra', by Wood; Vol.II: 'The principles of fluxions' by Samuel Vince; Vol.III Part I: 'The principles of mechanics" by Wood; and Vol.III Part II: "The principles of hydrostatics" by Samuel Vince; Vol.IV "The principles of astronomy" by Samuel Vince. Three other volumes -"A treatise on plane and spherical trigonometry" and "The elements of the conic sections" by Samuel Vince (1800) and "The elements of optics" by Wood (1801" may have been issued as part of the series.
Wood remained for sixty years at St. John's, serving as both President (1802–1815) and Master (1815–1839); on his death in 1839 he was interred in the college chapel and bequeathed his extensive library to the college, comprising almost 4,500 printed books on classics, history, mathematics, theology and travel, dating from the 17th to the 19th centuries.
Wood was also ordained as a priest in 1787 and served as Dean of Ely from 1820 until his death.
Publications
The Elements of Algebra (1795)
The Principles of Mechanics (1796)
The Elements of Optics (1798)
References
Notes
Other sources
W. W. Rouse Ball, A History of the Study of Mathematics at Cambridge University, 1889, repr. Cambridge University Press, 2009, , p. 110
Document 1:::
A hawk is a tool used to hold a plaster, mortar, or a similar material, so that the user can repeatedly, quickly and easily get some of that material on the tool which then applies it to a surface. A hawk consists of a board about 13 inches square with a perpendicular handle fixed centrally on the reverse. The user holds the hawk horizontally with the non-dominant hand and applies the material on the hawk with a tool held in the dominant hand.
Hawks are most often used by plasterers, along with finishing trowels, to apply a smooth finish of plaster to a wall. Brick pointers use hawks to hold mortar while they work. Hawks are also used to hold joint compound for taping and jointing.
The name "hawk" probably derives from the way the object rides on the user's arm, like a bird of prey.
References
de:Glättkelle
Document 2:::
The Dublin Institute of Technology (DIT) School of Electrical and Electronic Engineering (SEEE) was the largest and one of the longest established Schools of Electrical and Electronic Engineering in Ireland. It was located at the DIT Kevin Street Campus in Dublin City, as part of the College of Engineering & Built Environment (CEBE).
In 2019, DIT along with the Institute of Technology Blanchardstown (ITB) and the Institute of Technology Tallaght (ITT) became the founding institutes of the new Technological University Dublin (TU Dublin).
Overview
The DIT School of Electrical and Electronic Engineering was the largest education provider of Electrical and Electronic Engineering in Ireland in terms of programme diversity, staff and student numbers, covering a wide range of engineering disciplines including; Communications Engineering, Computer Engineering, Power Engineering, Electrical Services Engineering, Control Engineering, Energy Management and Electronic Engineering. The school included well established research centres in areas such as photonics, energy, antennas, communications and electrical power, with research outputs in; biomedical engineering, audio engineering, sustainable design, assistive technology and health informatics.
Educational courses in technical engineering commenced at Kevin St. Dublin 8 in 1887. The school sought accreditation for its programmes from the appropriate Irish and international professional body organisations, such as the Institution of Engineers of Ireland, offering education across the full range of third level National Framework of Qualifications (NFQ) Levels, from Level 6 to Level 10 (apprenticeships to post-doctoral degrees).
During the 2010s, the school delivered 23 individual programmes to over 1,200 students and had an output of approximately 350 graduates per year.
In 2015, the head of the school was Professor Michael Conlon.
In 2015, Electrical & Electronic Engineering was expected to be the first School from the C
Document 3:::
Sister chromatid cohesion refers to the process by which sister chromatids are paired and held together during certain phases of the cell cycle. Establishment of sister chromatid cohesion is the process by which chromatin-associated cohesin protein becomes competent to physically bind together the sister chromatids. In general, cohesion is established during S phase as DNA is replicated, and is lost when chromosomes segregate during mitosis and meiosis. Some studies have suggested that cohesion aids in aligning the kinetochores during mitosis by forcing the kinetochores to face opposite cell poles.
Cohesin loading
Cohesin first associates with the chromosomes during G1 phase. The cohesin ring is composed of two SMC (structural maintenance of chromosomes) proteins and two additional Scc proteins. Cohesin may originally interact with chromosomes via the ATPase domains of the SMC proteins. In yeast, the loading of cohesin on the chromosomes depends on proteins Scc2 and Scc4.
Cohesin interacts with the chromatin at specific loci. High levels of cohesin binding are observed at the centromere. Cohesin is also loaded at cohesin attachment regions (CARs) along the length of the chromosomes. CARs are approximately 500-800 base pair regions spaced at approximately 9 kilobase intervals along the chromosomes. In yeast, CARs tend to be rich in adenine-thymine base pairs. CARs are independent of origins of replication.
Establishment of cohesion
Establishment of cohesion refers to the process by which chromatin-associated cohesin becomes cohesion-competent. Chromatin association of cohesin is not sufficient for cohesion. Cohesin must undergo subsequent modification ("establishment") to be capable of physically holding the sister chromosomes together. Though cohesin can associate with chromatin earlier in the cell cycle, cohesion is established during S phase. Early data suggesting that S phase is crucial to cohesion was based on the fact that after S phase, sister chromatids are always found in the bound state. Tying establishment to DNA replication allows the cell to institute cohesion as soon as the sister chromatids are formed. This solves the problem of how the cell might properly identify and pair sister chromatids by ensuring that the sister chromatids are never separate once replication has occurred.
The Eco1/Ctf7 gene (yeast) was one of the first genes to be identified as specifically required for the establishment of cohesion. Eco1 must be present in S phase to establish cohesion, but its continued presence is not required to maintain cohesion. Eco1 interacts with many proteins directly involved in DNA replication, including the processivity clamp PCNA, clamp loader subunits, and a DNA helicase. Though Eco1 contains several functional domains, it is the acetyltransferase activity of the protein which is crucial for establishment of cohesion. During S phase, Eco1 acetylates lysine residues in the Smc3 subunit of cohesin. Smc3 remains acetylated until at least anaphase. Once cohesin has been removed from the chromatin, Smc3 is deacetylated by Hos1.
The Pds5 gene was also identified in yeast as necessary for the establishment of cohesion. In humans, the gene has two homologs, Pds5A and Pds5B. Pds5 interacts with chromatin-associated cohesin. Pds5 is not strictly establishment-specific, as Pds5 is necessary for maintenance of cohesion during G2 and M phase. The loss of Pds5 negates the requirement for Eco1. As such, Pds5 is often termed an "anti-establishment" factor.
In addition to interacting with cohesin, Pds5 also interacts with Wapl (wings apart-like), another protein that has been implicated in the regulation of sister chromatid cohesion. Human Wapl binds cohesin through the Scc cohesin subunits (in humans, Scc1 and SA1). Wapl has been tied to the loss of cohesin from the chromatids during M phase. Wapl interacts with Pds5 through phenylalanine-glycine-phenylalanine (FGF) sequence motifs.
One model of establishment of cohesion suggests that establishment is mediated by the replacement of Wapl in the Wapl-Pds5-cohesin complex with the Sororin protein. Like Wapl, Sororin contains an FGF domain and is capable of interacting with Pds5. In this model, put forward by Nishiyama et al., Wapl interacts with Pds5 and cohesin during G1, before establishment. During S phase, Eco1 (Esco1/Esco2 in humans) acetylates Smc3. This results in recruitment of Sororin. Sororin then replaces Wapl in the Pds5-cohesin complex. This new complex is the established, cohesion-competent cohesin state. At entry to mitosis, Sororin is phosphorylated and replaced again by Wapl, leading to loss of cohesion. Sororin also has chromatin binding activity independent of its ability to mediate cohesion.
Meiosis
Cohesion proteins SMC1ß, SMC3, REC8 and STAG3 appear to participate in the cohesion of sister chromatids throughout the meiotic process in human oocytes. SMC1ß, REC8 and STAG3 are meiosis specific cohesin proteins. The STAG3 protein is essential for female meiosis and fertility. Cohesins are involved in meiotic recombination.
Ties to DNA replication
A growing body of evidence ties establishment of cohesion to DNA replication. As mentioned above, functional coupling of these two processes prevents the cell from having to later distinguish which chromosomes are sisters by ensuring that the sister chromatids are never separate after replication.
Another significant tie between DNA replication and cohesion pathways is through Replication Factor C (RFC). This complex, the "clamp loader," is responsible for loading PCNA onto DNA. An alternative form of RFC is required for sister chromatin cohesion. This alternative form is composed of core RFC proteins RFC2, RFC3, RFC4, and RFC5, but replaces the RFC1 protein with cohesion specific proteins Ctf8, Ctf18, and Dcc1. A similar function-specific alternative RFC (replacing RFC1 with Rad24) plays a role in the DNA damage checkpoint. The presence of an alternative RFC in the cohesion pathway can be interpreted as evidence in support of the polymerase switch model for cohesion establishment. Like the non-cohesion RFC, the cohesion RFC loads PCNA onto DNA.
Some of the evidence tying cohesion and DNA replication comes from the multiple interactions of Eco1. Eco1 interacts with PCNA, RFC subunits, and a DNA helicase, Chl1, either physically or genetically. Studies have also found replication-linked proteins which influence cohesion independent of Eco1. The Ctf18 subunit of the cohesion-specific RFC can interact with cohesin subunits Smc1 and Scc1.
Polymerase switch model
Though the protein was originally identified as a Topoisomerase I redundant factor, the TRF4 gene product was later shown to be required for sister chromatid cohesion. Wang et al. showed that Trf4 is actually a DNA polymerase, which they called Polymerase κ. This polymerase is also referred to as Polymerase σ. In the same paper in which they identified Pol σ, Wang et al. suggested a polymerase switch model for establishment of cohesion. In this model, upon reaching a CAR, the cell switches DNA polymerases in a mechanism similar to that used in Okazaki fragment synthesis. The cell off-loads the processive replication polymerase and instead uses Pol σ for synthesis of the CAR region. It has been suggested that the cohesion-specific RFC could function in off-loading or on-loading PNCA and polymerases in such a switch.
Ties to DNA damage pathways
Changes in patterns of sister chromatid cohesion have been observed in cases of DNA damage. Cohesin is required for repair of DNA double-strand breaks (DSBs). One mechanism of DSB repair, homologous recombination (HR), requires the presence of the sister chromatid for repair at the break site. Thus, it is possible that cohesion is required for this process because it ensures that the sister chromatids are physically close enough to undergo HR. DNA damage can lead to cohesin loading at non-CAR sites and establishment of cohesion at these sites even during G2 phase. In the presence of ionizing radiation (IR), the Smc1 subunit of cohesin is phosphorylated by the ataxia telangiectasia mutated (ATM) kinase. ATM is a key kinase in the DNA damage checkpoint. Defects in cohesion can increase genome instability, a result consistent with the ties between cohesion and DNA damage pathways.
In the bacterium Escherichia coli, repair of mitomycin C-induced DNA damages occurs by a sister chromatid cohesion process involving the RecN protein. Sister chromatid interaction followed by homologous recombination appears to significantly contribute to the repair of DNA double-strand damages.
Medical relevance
Defects in the establishment of sister chromatid cohesion have serious consequences for the cell and are therefore tied to many human diseases. Failure to establish cohesion correctly or inappropriate loss of cohesion can lead to missegregation of chromosomes during mitosis, which results in aneuploidy. The loss of the human homologs of core cohesin proteins or of Eco1, Pds5, Wapl, Sororin, or Scc2 has been tied to cancer. Mutations affecting cohesion and establishment of cohesion are also responsible for Cornelia de Lange Syndrome and Roberts Syndrome. Diseases arising from defects in cohesin or other proteins involved in sister chromatid cohesion are referred to as cohesinopathies.
Cornelia de Lange Syndrome
Genetic alterations in genes NIPBL, SMC1A, SMC3, RAD21 and HDAC8 are associated with Cornelia de Lange Syndrome. The proteins encoded by these genes all function in the chromosome cohesion pathway that is employed in the cohesion of sister chromatids during mitosis, DNA repair, chromosome segregation and the regulation of developmental gene expression. Defects in these functions likely underlie many of the features of Cornelia de Lang Syndrome.
Document 4:::
David Negrete Fernández () was a Mexican colonel who participated in the Mexican Revolution. He was also a musician.
Biography
David fought alongside military officer Felipe Ángeles as a part of División del Norte.
He married Emilia Moreno Anaya, who bore him:
Consuelo Negrete Moreno
Jorge Alberto Negrete Moreno
Emilia Negrete Moreno
Teresa Negrete Moreno
David Negrete Moreno
Rubén Negrete Moreno
David was a math teacher in Mexico City. He was also a father-in-law of Elisa Christy and María Félix.
References
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the role of the Eco1/Ctf7 gene in the establishment of sister chromatid cohesion during the cell cycle?
A. It is required for maintaining cohesion after S phase.
B. It is necessary for the initial loading of cohesin on chromosomes.
C. It acetylates lysine residues in the Smc3 subunit of cohesin during S phase.
D. It interacts with chromatin-associated cohesin only in G1 phase.
Answer: | C. It acetylates lysine residues in the Smc3 subunit of cohesin during S phase. |
Relavent Documents:
Document 0:::
Homothallic refers to the possession, within a single organism, of the resources to reproduce sexually; i.e., having male and female reproductive structures on the same thallus. The opposite sexual functions are performed by different cells of a single mycelium.
It can be contrasted to heterothallic.
It is often used to categorize fungi. In yeast, heterothallic cells have mating types a and α. An experienced mother cell (one that has divided at least once) will switch mating type every cell division cycle because of the HO allele.
Sexual reproduction commonly occurs in two fundamentally different ways in fungi. These are outcrossing (in heterothallic fungi) in which two different individuals contribute nuclei to form a zygote, and self-fertilization or selfing (in homothallic fungi) in which both nuclei are derived from the same individual. Homothallism in fungi can be defined as the capability of an individual spore to produce a sexually reproducing colony when propagated in isolation. Homothallism occurs in fungi by a wide variety of genetically distinct mechanisms that all result in sexually reproducing cultures from a single cell.
Among the 250 known species of aspergilli, about 36% have an identified sexual state. Among those Aspergillus species for which a sexual cycle has been observed, the majority in nature are homothallic (self-fertilizing). Selfing in the homothallic fungus Aspergillus nidulans involves activation of the same mating pathways characteristic of sex in outcrossing species, i.e. self-fertilization does not bypass required pathways for outcrossing sex but instead requires activation of these pathways within a single individual. Fusion of haploid nuclei occurs within reproductive structures termed cleistothecia, in which the diploid zygote undergoes meiotic divisions to yield haploid ascospores.
Several ascomycete fungal species of the genus Cochliobolus (C. luttrellii, C. cymbopogonis, C. kusanoi and C. homomorphus) are homothalli
Document 1:::
In cosmology, a static universe (also referred to as stationary, infinite, static infinite or static eternal) is a cosmological model in which the universe is both spatially and temporally infinite, and space is neither expanding nor contracting. Such a universe does not have so-called spatial curvature; that is to say that it is 'flat' or Euclidean. A static infinite universe was first proposed by English astronomer Thomas Digges (1546–1595).
In contrast to this model, Albert Einstein proposed a temporally infinite but spatially finite model - static eternal universe - as his preferred cosmology during 1917, in his paper Cosmological Considerations in the General Theory of Relativity.
After the discovery of the redshift-distance relationship (deduced by the inverse correlation of galactic brightness to redshift) by American astronomers Vesto Slipher and Edwin Hubble, the Belgian astrophysicist and priest Georges Lemaître interpreted the redshift as evidence of universal expansion and thus a Big Bang, whereas Swiss astronomer Fritz Zwicky proposed that the redshift was caused by the photons losing energy as they passed through the matter and/or forces in intergalactic space. Zwicky's proposal would come to be termed 'tired light'—a term invented by the major Big Bang proponent Richard Tolman.
The Einstein universe
During 1917, Albert Einstein added a positive cosmological constant to his equations of general relativity to counteract the attractive effects of gravity on ordinary matter, which would otherwise cause a static, spatially finite universe to either collapse or expand forever.
This model of the universe became known as the Einstein World or Einstein's static universe.
This motivation ended after the proposal by the astrophysicist and Roman Catholic priest Georges Lemaître that the universe seems to be not static, but expanding. Edwin Hubble had researched data from the observations made by astronomer Vesto Slipher to confirm a relationship between reds
Document 2:::
gaaa The Britten–Davidson model, also known as the gene-battery model, is a hypothesis for the regulation of protein synthesis in eukaryotes. Proposed by Roy John Britten and Eric H. Davidson in 1969, the model postulates four classes of DNA sequence: an integrator gene, a producer gene, a receptor site, and a sensor site. The sensor site regulates the integrator gene, responsible for synthesis of activator RNA. The integrator gene cannot synthesize activator RNA unless the sensor site is activated. Activation and deactivation of the sensor site is done by external stimuli, such as hormones. The activator RNA then binds with a nearby receptor site, which stimulates the synthesis of mRNA at the structural gene.
This theory would explain how several different integrators could be concurrently synthesized, and would explain the pattern of repetitive DNA sequences followed by a unique DNA sequence that exists in genes.
See also
Transcriptional regulation
Operon
References
Document 3:::
The Internetowy System Aktów Prawnych ( in Polish), shortly ISAP, is a database with information about the legislation in force in Poland, which is part of the oldest and one of the most famous Polish legal information systems, and is publicly available on the website of the Sejm of the Republic of Poland.
References
Document 4:::
Antifragility is a property of systems in which they increase in capability to thrive as a result of stressors, shocks, volatility, noise, mistakes, faults, attacks, or failures. The concept was developed by Nassim Nicholas Taleb in his book, Antifragile, and in technical papers. As Taleb explains in his book, antifragility is fundamentally different from the concepts of resiliency (i.e. the ability to recover from failure) and robustness (that is, the ability to resist failure). The concept has been applied in risk analysis, physics, molecular biology, transportation planning, engineering, aerospace (NASA), and computer science.
Taleb defines it as follows in a letter to Nature responding to an earlier review of his book in that journal:
Antifragile versus robust/resilient
In his book, Taleb stresses the differences between antifragile and robust/resilient. "Antifragility is beyond resilience or robustness. The resilient resists shocks and stays the same; the antifragile gets better." The concept has now been applied to ecosystems in a rigorous way. In their work, the authors review the concept of ecosystem resilience in its relation to ecosystem integrity from an information theory approach. This work reformulates and builds upon the concept of resilience in a way that is mathematically conveyed and can be heuristically evaluated in real-world applications: for example, ecosystem antifragility. The authors also propose that for socio-ecosystem governance, planning or in general, any decision making perspective, antifragility might be a valuable and more desirable goal to achieve than a resilience aspiration. In the same way, Pineda and co-workers have proposed a simply calculable measure of antifragility, based on the change of “satisfaction” (i.e., network complexity) before and after adding perturbations, and apply it to random Boolean networks (RBNs). They also show that several well known biological networks such as Arabidopsis thaliana cell-cycle are as ex
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What role does the Foundation for Biomedical Research (FBR) play in relation to animal research?
A. It advocates against the use of animals in research.
B. It informs various groups about the necessity of animal research in medicine.
C. It solely focuses on legislative activism related to animal rights.
D. It provides funding exclusively for research on nonhuman primates.
Answer: | B. It informs various groups about the necessity of animal research in medicine. |
Relavent Documents:
Document 0:::
The 12-bit ND812, produced by Nuclear Data, Inc., was a commercial minicomputer developed for the scientific computing market.
Nuclear Data introduced it in 1970 at a price under $10,000 ().
Description
The architecture has a simple programmed I/O bus, plus a DMA channel.
The programmed I/O bus typically runs low to medium-speed peripherals, such as printers,
teletypes, paper tape punches and readers, while DMA is used for cathode ray tube
screens with a light pen, analog-to-digital converters, digital-to-analog converters,
tape drives, disk drives.
The word size, 12 bits, is large enough to handle unsigned integers from 0 to 4095 –
wide enough for controlling simple machinery. This is also enough to handle signed numbers from -2048 to +2047.
This is higher precision than a slide rule or most analog computers. Twelve bits could also store two
six-bit characters (note, six-bit isn't enough for two cases, unlike "fuller" ASCII
character set). "ND Code" was one such 6-bit character encoding that included upper-case alphabetic, digit,
a subset of punctuation and a few control characters.
The ND812's basic configuration has a main memory of 4,096 twelve-bit words
with a 2 microsecond cycle time. Memory is expandable to 16K words in 4K word increments. Bits within the word
are numbered from most significant bit (bit 11) to
least significant bit (bit 0).
The programming model consists of four accumulator registers: two main accumulators, J and K,
and two sub accumulators, R and S. A rich set of arithmetic and logical operations are provided for the
main accumulators and instructions are provided to exchange data between the main and sub accumulators.
Conditional execution is provided through "skip" instructions. A condition is tested and the subsequent
instruction is either executed or skipped depending on the result of the test. The subsequent instruction
is usually a jump instruction when more than one instruction is needed for the case where the test fails.
Document 1:::
The Fischer oxazole synthesis is a chemical synthesis of an oxazole from a cyanohydrin and an aldehyde in the presence of anhydrous hydrochloric acid. This method was discovered by Emil Fischer in 1896. The cyanohydrin itself is derived from a separate aldehyde. The reactants of the oxazole synthesis itself, the cyanohydrin of an aldehyde and the other aldehyde itself, are usually present in equimolar amounts. Both reactants usually have an aromatic group, which appear at specific positions on the resulting heterocycle.
A more specific example of Fischer oxazole synthesis involves reacting mandelic acid nitrile with benzaldehyde to give 2,5-diphenyl-oxazole.
History
Fischer developed the Fischer oxazole synthesis during his time at Berlin University. The Fischer oxazole synthesis was one of the first syntheses developed to produce 2,5-disubstituted oxazoles.
Mechanism
The Fischer oxazole synthesis is a type of dehydration reaction which can occur under mild conditions in a rearrangement of the groups that would not seem possible. The reaction occurs by dissolving the reactants in dry ether and passing through the solution dry, gaseous hydrogen chloride. The product, which is the 2,5-disubstituted oxazole, precipitates as the hydrochloride and can be converted to the free base by the addition of water or by boiling with alcohol.
The cyanohydrins and aldehydes used for the synthesis are usually aromatic, however there have been instances where aliphatic compounds have been used.
The first step of the mechanism is the addition of gaseous HCl to the cyanohydrin 1. The cyanohydrin abstracts the hydrogen from HCl while the chloride ion attacks the carbon in the cyano group. This first step results in the formation of an iminochloride intermediate 2, probably as the hydrochloride salt. This intermediate then reacts with the aldehyde; the lone pair of the nitrogen attacks the electrophilic carbonyl carbon on the aldehyde.
The following step results in an SN2 attack fo
Document 2:::
Base Number (BN) is a measurement of basicity that is expressed in terms of the number of milligrams of potassium hydroxide per gram of oil sample (mg KOH/g). BN is an important measurement in petroleum products, and the value varies depending on its application. BN generally ranges from 6–8 mg KOH/g in modern lubricants, 7–10 mg KOH/g for general internal combustion engine use and 10–15 mg KOH/g for diesel engine operations. BN is typically higher for marine grade lubricants, approximately 15-80 mg KOH/g, as the higher BN values are designed to increase the operating period under harsh operating conditions, before the lubricant requires replacement.
Oil Additives
An oil formulation consists of the base or stock oil and oil additives. Most oil formulations contain basic additives and detergents, designed to react with and neutralise acids, preventing damage to engine parts, including corrosion of metal surfaces.
Potentiometric determination
Although IP Standard test methods exist, the more common methods for BN are ASTM standardised, such as the potentiometric titration for fresh oils (Test method BN ASTM D2896). A sample is typically dissolved in a pre-mixed solvent of chlorobenzene and acetic acid and titrated with standardised perchloric acid in glacial acetic acid for fresh oil samples. The end point is detected using a glass electrode which is immersed in an aqueous solution containing the sample, and connected to a voltmeter/potentiometer. This causes an ion exchange in the outer solvated layer at the glass membrane, so a change in potential is generated which can be measured by the electrode. When the end point of the chemical reaction is reached, which is shown by an inflection point on the titration curve using a specified detection system, the amount of titrant required is used to generate a result which is reported in milligrams of potassium hydroxide equivalent per gram of sample (mg of KOH/g). Potentiometric titration for used oils (Test method BN A
Document 3:::
The Health Products and Food Branch (HPFB) of Health Canada manages the health-related risks and benefits of health products and food by minimizing risk factors while maximizing the safety provided by the regulatory system and providing information to Canadians so they can make healthy, informed decisions about their health.
HPFB has ten operational Directorates with direct regulatory responsibilities:
Biologics and Genetic Therapies Directorate
Food Directorate
Marketed Health Products Directorate (with responsibility for post-market surveillance)
Medical Devices Directorate
Natural Health Products Directorate
Office of Nutrition Policy and Promotion
Pharmaceutical Drugs Directorate
Policy, Planning and International Affairs Directorate
Resource Management and Operations Directorate
Veterinary Drugs Directorate
Extraordinary Use New Drugs
Extraordinary Use New Drugs (EUNDs) is a regulatory programme under which, in times of emergency, drugs can be granted regulatory approval under the Food and Drug Act and its regulations. An EUND approved through this pathway can only be sold to federal, provincial, territorial and municipal governments. The text of the EUNDs regulations is available.
On 25 March 2011 and after the pH1N1 pandemic, amendments were made to the Food and Drug Regulations (FDR) to include a specific regulatory pathway for EUNDs. Typically, clinical trials in human subjects are conducted and the results are provided as part of the clinical information package of a New Drug Submission (NDS) to Health Canada, the federal authority that reviews the safety and efficacy of human drugs.
Health Canada recognizes that there are circumstances in which sponsors cannot reasonably provide substantial evidence demonstrating the safety and efficacy of a therapeutic product for NDS as there are logistical or ethical challenges in conducting the appropriate human clinical trials. The EUND pathway was developed to allow a mechanism for authorization of th
Document 4:::
The Rogue River–Siskiyou National Forest is a United States National Forest in the U.S. states of Oregon and California. The formerly separate Rogue River and Siskiyou National Forests were administratively combined in 2004. Now, the Rogue River–Siskiyou National Forest ranges from the crest of the Cascade Range west into the Siskiyou Mountains, covering almost . Forest headquarters are located in Medford, Oregon.
Geography
The former Rogue River portion of the Rogue River–Siskiyou National Forest is located in parts of five counties in southern Oregon and northern California. In descending order of land area they are Jackson, Klamath, Douglas, Siskiyou, and Josephine counties, with Siskiyou County being the only one in California. It has a land area of . There are local ranger district offices located in Ashland, Butte Falls, Grants Pass, Jacksonville, and Prospect.
The former Siskiyou portion of the Rogue River–Siskiyou National Forest is located in parts of four counties in southwestern Oregon and northwestern California. In descending order of land area they are Curry, Josephine, and Coos counties in Oregon and Del Norte County in California. It has a land area of . There are local ranger district offices located in Cave Junction, Gold Beach, and Powers.
Nearly all of the national forest is mountainous and includes parts of the Southern Oregon Coast Range, the Klamath Mountains, and the Cascade Range.
The largest river in the national forest is the Rogue River, which originates in the Cascade Range and flows through the Klamath Mountains and Coast Range. The Illinois River is a major tributary of the Rogue in the Klamath Mountains, while the Sixes, Elk, Pistol, Chetco, and Winchuck rivers drain the Coast Range directly to the Pacific Ocean.
Climate
History
The Siskiyou National Forest was established on October 5, 1906. On July 1, 1908, it absorbed Coquille National Forest and other lands. Rogue River National Forest traces its establishment back to the creation of the Ashland Forest Reserve on September 28, 1893, by the United States General Land Office. The lands were transferred to the Forest Service in 1906, and it became a National Forest on March 4, 1907. On July 1, 1908, Ashland was combined with other lands from Cascade, Klamath and Siskiyou National Forests to establish Crater National Forest. On July 18, 1915, part of Paulina National Forest was added, and on July 9, 1932, the name was changed to Rogue River.
World War II bombing
On September 9, 1942, an airplane dropped bombs on Mount Emily in the Siskiyou National Forest, turned around, and flew back over the Pacific Ocean. The bombs exploded and started a fire, which was put out by several forest service employees. Bomb fragments were said to have Japanese markings. Stewart Holbrook vividly described this event in his essay "First Bomb". It was later confirmed that the plane was indeed Japanese, and the incident became known as the Lookout Air Raids. It was the second bombing of the continental United States by an enemy aircraft, three months after the air attack by Japan on Dutch Harbor three months earlier on June 3–4.
Natural features
The national forest is home to some stands of old growth, including Port Orford cedar and Douglas fir in the Copper Salmon area. A 1993 Forest Service study estimated that the extent of old growth in the forest was some of which occurs in the Red Buttes Wilderness. Blue oak, Quercus douglasii, and Canyon live oak, Quercus chrysolepis occur in the Siskiyou National Forest. For the California endemic Blue Oak, the disjunctive stands are occurring near the northern limit of its range, which occur no farther north than Del Norte County. The world's tallest pine tree is a ponderosa and is located in the national forest.
In 2002, the massive Biscuit Fire burned nearly , including much of the Kalmiopsis Wilderness.
Protected areas
The Rogue River–Siskiyou National Forest contains all or part of eight separate wilderness areas, which together add up to :
Copper Salmon Wilderness -
Grassy Knob Wilderness -
Kalmiopsis Wilderness -
Red Buttes Wilderness -
Rogue–Umpqua Divide Wilderness -
Siskiyou Wilderness -
Sky Lakes Wilderness -
Wild Rogue Wilderness -
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What significant event occurred on September 9, 1942, in the Siskiyou National Forest?
A. The establishment of the forest
B. A bombing incident by a Japanese airplane
C. The first recorded fire in the forest
D. The combination of Rogue River and Siskiyou National Forests
Answer: | B. A bombing incident by a Japanese airplane |
Relavent Documents:
Document 0:::
A spring house, or springhouse, is a small building, usually of a single room, constructed over a spring. While the original purpose of a springhouse was to keep the spring water clean by excluding fallen leaves, animals, etc., the enclosing structure was also used for refrigeration before the advent of ice delivery and, later, electric refrigeration. The water of the spring maintains a constant cool temperature inside the spring house throughout the year. Food that would otherwise spoil, such as meat, fruit, or dairy products, could be kept there, safe from animal depredations as well. Springhouses thus often also served as pumphouses, milkhouses and root cellars.
The Tomahawk Spring spring house at Tomahawk, West Virginia, was listed on the National Register of Historic Places in 1994.
Gallery
See also
Ice house (building)
Smokehouse
Windcatcher
External links
Document 1:::
Biodermogenesi is a procedure adopted in dermatology to promote skin regeneration. The system makes it possible to reorganize the skin layers and stimulate the regeneration of collagen, elastic fibers and basal cells through the reactivation of intra- and extracellular exchange. The therapy is based on the combined delivery of electromagnetic fields, vacuum and electrostimulation (V-EMF therapy). The literature shows that it is generally pleasant and relaxing for patients and has been found to be effective in the anti-aging therapy, of stretch marks and scars, always in the absence of side effects.
See Also
V-EMF therapy
Document 2:::
Mycroft was a free and open-source software virtual assistant that uses a natural language user interface. Its code was formerly copyleft, but is now under a permissive license. It was named after a fictional computer from the 1966 science fiction novel The Moon Is a Harsh Mistress.
Unusually for a voice-controlled assistant, Mycroft did all of its processing locally, not on a cloud server belonging to the vendor. It could access online resources, but it could also function without an internet connection.
In early 2023, Mycroft AI ceased development. A community-driven platform continues with OpenVoiceOS.
History
Inspiration for Mycroft came when Ryan Sipes and Joshua Montgomery were visiting a makerspace in Kansas City, MO, where they came across a simple and basic intelligent virtual assistant project. They were interested in the technology, but did not like its inflexibility. Montgomery believes that the burgeoning industry of intelligent personal assistance poses privacy concerns for users, and has promised that Mycroft will protect privacy through its open source machine learning platform.
Mycroft AI, Inc., has won several awards, including the prestigious Techweek's KC Launch competition in 2016. They were part of the Sprint Accelerator 2016 class in Kansas City and joined 500 Startups Batch 20 in February 2017. The company accepted a strategic investment from Jaguar Land Rover during this same time period. The company had raised more than $2.5 million from institutional investors before they opted to offer shares of the company to the public through StartEngine, an equity crowdfunding platform.
In early 2023, Mycroft AI ceased development.
Software
Mycroft voice stack
Mycroft provides free software for most parts of the voice stack.
Wake Word
Mycroft does Wake Word spotting, also called keyword spotting, through its Precise Wake Word engine. Prior to Precise becoming the default Wake Word engine, Mycroft employed PocketSphinx. Instead of being ba
Document 3:::
A memory protection unit (MPU) is a computer hardware unit that provides memory protection. It is usually implemented as part of the central processing unit (CPU). MPU is a trimmed down version of memory management unit (MMU) providing only memory protection support. It is usually implemented in low power processors that require only memory protection and do not need the full-fledged feature of a MMU like virtual memory management.
Overview
The MPU allows the privileged software to define memory regions and assign memory access permission and memory attributes to each of them. Depending on the implementation of the processor, the number of supported memory regions will vary. The MPU on ARMv8-M processors supports up to 16 regions. The memory attributes define the ordering and merging behaviors of these regions, as well as caching and buffering attributes. Cache attributes can be used by internal caches, if available, and can be exported for use by system caches.
MPU monitors transactions, including instruction fetches and data accesses from the processor, which can trigger a fault exception when an access violation is detected. The main purpose of memory protection is to prevent a process from accessing memory that has not been allocated to it. This prevents a bug or malware within a process from affecting other processes, or the operating system itself.
References
Document 4:::
The Minkowski content (named after Hermann Minkowski), or the boundary measure, of a set is a basic concept that uses concepts from geometry and measure theory to generalize the notions of length of a smooth curve in the plane, and area of a smooth surface in space, to arbitrary measurable sets.
It is typically applied to fractal boundaries of domains in the Euclidean space, but it can also be used in the context of general metric measure spaces.
It is related to, although different from, the Hausdorff measure.
Definition
For , and each integer m with , the m-dimensional upper Minkowski content is
and the m-dimensional lower Minkowski content is defined as
where is the volume of the (n−m)-ball of radius r and is an -dimensional Lebesgue measure.
If the upper and lower m-dimensional Minkowski content of A are equal, then their common value is called the Minkowski content Mm(A).
Properties
The Minkowski content is (generally) not a measure. In particular, the m-dimensional Minkowski content in Rn is not a measure unless m = 0, in which case it is the counting measure. Indeed, clearly the Minkowski content assigns the same value to the set A as well as its closure.
If A is a closed m-rectifiable set in Rn, given as the image of a bounded set from Rm under a Lipschitz function, then the m-dimensional Minkowski content of A exists, and is equal to the m-dimensional Hausdorff measure of A.
Footnotes
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the primary purpose of a memory protection unit (MPU) in computer systems?
A. To manage virtual memory for applications
B. To provide memory protection and prevent unauthorized access
C. To enhance the speed of data processing
D. To control power consumption in processors
Answer: | B. To provide memory protection and prevent unauthorized access |
Relavent Documents:
Document 0:::
Difelikefalin, sold under the brand name Korsuva, is an opioid peptide used for the treatment of moderate to severe itch. It acts as a peripherally-restricted, highly selective agonist of the κ-opioid receptor (KOR).
Difelikefalin acts as an analgesic by activating KORs on peripheral nerve terminals and KORs expressed by certain immune system cells. Activation of KORs on peripheral nerve terminals results in the inhibition of ion channels responsible for afferent nerve activity, causing reduced transmission of pain signals, while activation of KORs expressed by immune system cells results in reduced release of proinflammatory, nerve-sensitizing mediators (e.g., prostaglandins).
Difelikefalin was approved for medical use in the United States in August 2021. The U.S. Food and Drug Administration considers it to be a first-in-class medication.
Society and culture
Legal status
On 24 February 2022, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Kapruvia, intended for treatment of moderate-to-severe pruritus associated with chronic kidney disease. The applicant for this medicinal product is Vifor Fresenius Medical Care Renal Pharma France. Difelikefalin was approved for medical use in the European Union in April 2022.
Research
It is under development by Cara Therapeutics as an intravenous agent for the treatment of postoperative pain. An oral formulation has also been developed. Due to its peripheral selectivity, difelikefalin lacks the central side effects like sedation, dysphoria, and hallucinations of previous KOR-acting analgesics such as pentazocine and phenazocine. In addition to use as an analgesic, difelikefalin is also being investigated for the treatment of pruritus (itching). Difelikefalin has completed phase II clinical trials for postoperative pain and has demonstrated significant and "robust" clinical
Document 1:::
The World Vegetable Center (WorldVeg) (), previously known as the Asian Vegetable Research and Development Center (AVRDC), is an international, nonprofit institute for vegetable research and development. It was founded in 1971 in Shanhua, southern Taiwan, by the Asian Development Bank, Taiwan, South Korea, Japan, the Philippines, Thailand, the United States and South Vietnam.
WorldVeg aims to reduce malnutrition and alleviate poverty in developing nations through improving production and consumption of vegetables.
History
The World Vegetable Center was founded as the Asian Vegetable Research and Development Center (AVRDC) in 1971 by the Asian Development Bank, Taiwan, South Korea, Japan, the Philippines, Thailand, the United States and South Vietnam. The main campus was opened in 1973. In 2008 the center was rebranded as the World Vegetable Center.
For the first 20 years of its existence the World Vegetable Center was a major global sweet potato research center with over 1,600 accessions in their first two years of operation. In 1991 the World Vegetable Center chose to end its sweet potato research due to high costs and other institutions with a tighter focus coming into existence. The WVC duplicated and transferred its research and germplasm to the International Potato Center and Taiwan Agricultural Research institute.
Research and development
The use of vegetables as crops that are of high worth is important in the Sustainable Development Goals of the United Nations Development Program and the World Vegetable Center. The vegetables bred by the Center can be used in poorer areas, where they can serve as an important source of income and can help fight micronutrient deficiencies.
The Center's current crop portfolio focuses on several groups of globally important vegetables, according to the WorldVeg:
solanaceous crops: (tomato, sweet pepper, chili pepper, eggplant)
bulb alliums (onion, shallot, garlic)
cucurbits (Cucurbitaceae): (cucumbers, pumpkins)
Indigeno
Document 2:::
In memory addressing for Intel x86 computer architectures, segment descriptors are a part of the segmentation unit, used for translating a logical address to a linear address. Segment descriptors describe the memory segment referred to in the logical address.
The segment descriptor (8 bytes long in 80286 and later) contains the following fields:
A segment base address
The segment limit which specifies the segment size
Access rights byte containing the protection mechanism information
Control bits
Structure
The x86 and x86-64 segment descriptor has the following form:
What the fields stand for:
Base Address Starting memory address of the segment. Its length is 32 bits and it is created from the lower part bits 16 to 31, and the upper part bits 0 to 7, followed by bits 24 to 31.
Segment Limit Its length is 20 bits and is created from the lower part bits 0 to 15 and the upper part bits 16 to 19. It defines the address of the last accessible data. The length is one more than the value stored here. How exactly this should be interpreted depends on the Granularity bit of the segment descriptor.
G=Granularity If clear, the limit is in units of bytes, with a maximum of 220 bytes. If set, the limit is in units of 4096-byte pages, for a maximum of 232 bytes.
D/B
D = Default operand size : If clear, this is a 16-bit code segment; if set, this is a 32-bit segment.
B = Big: If set, the maximum offset size for a data segment is increased to 32-bit 0xffffffff. Otherwise it's the 16-bit max 0x0000ffff. Essentially the same meaning as "D".
L=Long If set, this is a 64-bit segment (and D must be zero), and code in this segment uses the 64-bit instruction encoding. "L" cannot be set at the same time as "D" aka "B". (Bit 21 in the image)
AVL=Available For software use, not used by hardware (Bit 20 in the image with the label A)
P=Present If clear, a "segment not present" exception is generated on any reference to this segment
DPL=Descriptor privilege lev
Document 3:::
Botanical gardens in Bulgaria sometimes have collections consisting entirely of native and endemic species; most have a collection that include plants from around the world. There are botanical gardens and arboreta in all states and territories of Bulgaria, most are administered by local governments, some are privately owned.
– Balchik
– Varna
Sofia University Botanical garden, Sofia – Sofia
– Sofia
University of Forestry Botanical garden – Sofia
Document 4:::
Bridgwater tidal barrier will be a flood control gate located on the River Parrett in Bridgwater, Somerset, England. The River Parrett is tidal for some upstream of Bridgwater, and the combination of flooding on the Somerset Levels and high tides reaching up the Bristol Channel, have a detrimental effect on the whole area. In 2022, a tidal flood gate was approved to be installed at a cost of £249 million, which is expected to be operational by 2027.
History
Historically, flooding on the River Parrett has occurred when both excess rainwater and high tides in the Bristol Channel, backflow upstream on the river. In December 1929, serious flooding upstream at Lyng and Athelney was in danger of overwhelming those villages, and to prevent this, the locals suggested cutting the dykes, but this would release a "tidal wave" high, and combined with near incoming tide, it was feared mass flooding would occur in the Bridgwater area. However, by early 1930, the locals had abandoned this idea and they seem "resigned to their fate." Several times, locals on the Somerset Levels have complained that their settlements have been sacrificed to save Bridgwater, but one Environment Agency official noted that that is what the Somerset Levels are supposed to do; retain the floodwater and release it slowly.
Serious floods occurred in 1960, and as a result, defences against flooding were built along the Parrett catchment. One of the suggestions put forward after the 2014 floods was to build a giant lagoon in Bridgwater Bay which could generate electricity through the flowing of the tides, but could be allowed to store fresh floodwater and release it into the sea at low tide. Future flooding is based on modelling and estimates from the Environment Agency, which detail an increase of 20% of peak flow in all watercourses, coupled with a sea level rise of by the year 2100.
In December 2019, proposals for the barrier were submitted in response to severe flooding in Somerset in 2014. The
The following are multiple choice questions (with answers) about knowledge and skills in advanced master-level STEM courses.
What is the primary purpose of botanical gardens in Bulgaria?
A. To showcase only native species
B. To preserve global plant diversity
C. To serve as private recreational spaces
D. To exclusively collect endemic species
Answer: | B. To preserve global plant diversity |
End of preview. Expand
in Data Studio
No dataset card yet
- Downloads last month
- 26