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Cryptozoology (from Greek κρυπτός, kryptos, "hidden" + zoology; literally, "study of hidden animals") is a pseudoscience involving the search for animals whose existence has not been proven. The animals cryptozoologists study are often referred to as cryptids, a term coined by John Wall in 1983.[1] This includes looking for living examples of animals that are considered extinct, such as non-avian dinosaurs; animals whose existence lacks physical evidence but which appear in myths, legends, or are reported, such as Bigfoot and Chupacabra;[2] and wild animals dramatically outside their normal geographic ranges, such as phantom cats (also known as Alien Big Cats).
Cryptozoology is not a recognized branch of zoology or a discipline of science.[2] It is an example of pseudoscience because it relies heavily upon anecdotal evidence, stories and alleged sightings.[3][4][5]
The coining of the word cryptozoology is often attributed to Belgian-French zoologist Bernard Heuvelmans, though Heuvelmans attributes coinage of the term to the late Scottish explorer and adventurer Ivan T. Sanderson.[6] Heuvelmans' 1955 book On the Track of Unknown Animals traces the scholarly origins of the discipline to Anthonie Cornelis Oudemans and his 1892 study, The Great Sea Serpent.[7] Heuvelmans argued that cryptozoology should be undertaken with scientific rigor, but with an open-minded, interdisciplinary approach. He also stressed that attention should be given to local, urban and folkloric sources regarding such creatures, arguing that while often layered in unlikely and fantastic elements, folktales can have small grains of truth and important information regarding undiscovered organisms. Phantom cats (an example of living animals supposedly found outside of their normal range) are a common subject of cryptozoological interest,[8] largely due to the relative likelihood of existence in comparison to fantastical cryptids lacking any evidence of existence, such as Mothman.[9][10]
Another notable book on the subject is Willy Ley's Exotic Zoology (1959). Ley was best known for his writings on rocketry and related topics, but he was trained in paleontology, and wrote a number of books about animals. Ley's collection Exotic Zoology is of some interest to cryptozoology, as he discusses the Yeti and sea serpents, as well as relict dinosaurs. The book entertains the possibility that some legendary creatures (like the sirrush, the unicorn or the cyclops) might be based on actual animals, through misinterpretation of the animals and/or their remains. Also notable is the work of British zoologist and cryptozoologist Karl Shuker, who has published 12 books and countless articles on numerous cryptozoological subjects since the mid-1980s. Loren Coleman, a modern popularizer of cryptozoology, has chronicled the history and personalities of cryptozoology in his books.[11]
Main article: List of cryptids
An Okapi at Walt Disney's Animal Kingdom, symbol of the defunct International Society of Cryptozoology
Many species appear in cryptozoological literature, including mythical and folkloric animals, such as Bigfoot and the Loch Ness Monster, which have appeared commonly as cultural references, and within TV, movies, and other media. A few extant species such as the okapi and mountain gorilla are also commonly used by cryptozoologists as examples of animals they say were previously thought to be cryptids, but are now known to exist.[12] These species are rarely anticipated by cryptozoologists before their discovery by science, but are nonetheless often depicted as hallmarks of cryptozoology.[citation needed]
The 2003 discovery of the fossil remains of Homo floresiensis was cited by paleontologist Henry Gee, editor of the journal Nature, as possible evidence that humanoid cryptids like the Orang Pendek and yeti were "founded on grains of truth." "Cryptozoology," Gee said, "the study of such fabulous creatures, can come in from the cold."[18] While cryptozoologists are often unable to properly follow the scientific method due to the nature of their work, the vast majority still reject supernatural explanations for cryptid sightings, preferring to keep explanations as plausible as possible without ruling out the cryptid's existence.[citation needed]
Cryptozoology has been criticised because of its reliance on anecdotal information[19] and because some cryptozoologists do not follow the scientific method[20][21] and devote a substantial portion of their efforts to investigations of animals that most scientists believe are unlikely to have existed.[22]
Cryptozoologists contend that because species once considered superstition, hoaxes, delusions, or misidentifications were later accepted as legitimate by the scientific community, descriptions and reports of folkloric creatures should be taken seriously.[23]
According to Mike Dash, a Welsh historian, few scientists doubt there are thousands of unknown animals, particularly invertebrates, awaiting discovery; however, cryptozoologists are largely uninterested in researching and cataloging newly discovered species of ants or beetles, instead focusing their efforts towards "more elusive" creatures that have often defied decades of work aimed at confirming their existence.[22] The majority of mainstream criticism of cryptozoology is thus directed towards the search for megafauna cryptids such as Bigfoot, the Yeti, and the Loch Ness Monster, which appear often in popular culture, but for which there is little or no scientific support. Some scientists argue that megafauna cryptids are unlikely to exist undetected in great enough numbers to maintain a breeding population[24] and are unlikely to be able to survive in their reported habitats owing to issues of climate and food supply.[25]
Another criticism is that actual discoveries of new species have rarely, if ever, been predicted by cryptozoologists. Critics note that while other researchers have stumbled upon real animals, cryptozoologists have focused on finding legendary creatures with no success.[26]
See also[edit]
 1. ^ Coleman, Loren and Clark, Jerome.Cryptozoology A to Z: The Encyclopedia of Loch Monsters, Sasquatch, Chupacabras, and Other Authentic Mysteries of Nature. New York: Fireside/Simon and Schuster, 1999
 2. ^ a b Simpson, George G. (1984). "Mammals and Cryptozoology". Proceedings of the American Philosophical Society (American Philosophical Society.) 128 (1): 1–19. JSTOR 986487.
 3. ^ Carroll, Robert T. (1994–2009). "The Skeptic's Dictionary". Retrieved 26 August 2010.
 4. ^ Shermer, Michael; Linse, Pat (2002). The Skeptic Encyclopedia of Pseudoscience. ABC-CLIO. ISBN 1-57607-653-9.
 5. ^ H. James Birx (6 January 2009). Encyclopedia of time: science, philosophy, theology, & culture. SAGE. pp. 251–. ISBN 978-1-4129-4164-8. Retrieved 2 September 2011.
 6. ^ Heuvelmans, Bernard (1968). In the Wake of the Sea-Serpents. New York: Hill and Wang. ISBN 0-8090-5814-6.
 7. ^ Bernard Heuvelmans (1965). On The Track Of Unknown Animals. New York: Hill and Wang. ISBN 0-7103-0498-6.
 8. ^ Cryptozoology/Big Cats at DMOZ
 9. ^ "Big Cat evidence gets stronger, as society calls for government study". British Big Cats Society. Retrieved 2010-02-09.
 10. ^ Brad Fear (2008). A Macabre Myth of a Moth-Man. ISBN 1-4389-0264-6.
 11. ^ Loren Coleman (2002). Tom Slick: True Life Encounters in Cryptozoology. Fresno, California: Craven Street Books/Linden Press. ISBN 0-941936-74-0.
 12. ^ Margaret Mittelbach; Michael Crewdson (2 April 2009). Carnivorous Nights: On the Trail of the Tasmanian Tiger. Random House Digital, Inc. pp. 10–. ISBN 978-0-307-51683-1. Retrieved 1 February 2013.
 13. ^ Channel, Eden (October 2, 2012). "Komodo Dragons | Reptiles | Animals | Nature | Eden Channel". Retrieved April 11, 2013.
 14. ^ Ciofi, Claudio. "The Komodo Dragon". Scientific American. Retrieved April 11, 2013.
 15. ^ Coleman, Loren; Patrick Huyghe (2003). The Field Guide to Lake Monsters, Sea Serpents, and other mystery denizens of the deep. Penguin Books. ISBN 1-58542-252-5.
 16. ^ News Service, Vietnam (May 28, 2006). "The legend of the Hoan Kiem Turtle". Asian Turtle Conservation Network. Retrieved 20 December 2010.
 17. ^ Krystek, Lee. "A Gallery of Crypto


Seed: Conceal
Illusion (Glamer)
Spellcraft DC: 17
Components: V, S
Casting Time: 1 minute
Range: Personal or touch
Target: You or a creature or object of up to 2,000 lb.
Duration: 200 minutes or until expended (D)
Saving Throw: None or Will negates (harmless, object)
Spell Resistance: No or Yes (harmless, object)
This seed can conceal a creature or object touched from sight, even from darkvision. If the subject is a creature carrying gear, the gear vanishes too, rendering the creature invisible. A spell using the conceal seed ends if the subject attacks any creature. Actions directed at unattended objects do not break the spell, and causing harm indirectly is not an attack. To create invisibility that lasts regardless of the actions of the subject, increase the Spellcraft DC by +4. Alternatively, this seed can conceal the exact location of the subject so that it appears to be about 2 feet away from its true location; this increases the Spellcraft DC by +2. The subject benefits from a 50% miss chance as if it had total concealment. However, unlike actual total concealment, this displacement effect does not prevent enemies from targeting him or her normally. The conceal seed can also be used to block divination spells, spell-like effects, and epic spells developed using the reveal seed; this increases the Spellcraft DC by +6. In all cases where divination magic of any level, including epic level, is employed against the subject of a spell using the conceal seed for this purpose, an opposed caster level check determines which spell works.


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Reasons Why People Like Sports Cars
Sports cars are performance vehicles that offer driving satisfaction and pleasure. They permit someone to participate in the complete driving experience and become in contact directly using the highway or road, as diametrically as you possibly can. Within the automobile industry where economy vehicles, "family sedans" and SUV's dominate the area, sports cars certainly stick out.
Like Sports CarsDue to this driving pleasure, so many people are attracted to some sports vehicle. This is among the numerous explanations why people such as these vehicles. Some other reasons include:
1. Appearance. The aerodynamic style of a sports vehicle causes it to be attractive to vehicle fans. Although when you're making a car investment, this shouldn't be the main or only need to purchase that vehicle. Functionality ought to be the primary consideration despite the fact that beauty may also enter your choice.
2. Driving characteristics. While other motor vehicles mostly are created for affordability and performance, sports cars gives focus on performance and execution. The trait and condition of driving a sports vehicle is definitely an experience frequently unmatched.
Bearing in mind their discriminating vehicle motorists, sports cars easily beat the street execution of other automobiles. Motorists can rapidly accelerate when needed, hug turns, and also have a certain driving management not given by most vehicles.
3. Excitement and fun. The driving characteristics of the sports vehicle can offer excitement and fun.
An individual can spend hrs speaking about exciting encounters for example curve hugging wile not implementing one's feet from the accelerator or zooming past slow moving traffic yet residing in full control or discuss the sense of gratification, and understanding that the first is driving a vehicle with superb engineering.
4. Duration and resale value. Each new automobile depreciates the second it's driven. However, sports cars will end up worth more after a while, due to their above-pointed out characteristics and therefore are likely to become potential classics which will retain their value.
One doesn't need to make their vehicle choice an announcement, although if a person chooses, the chance is appropriate there. Having a sports vehicle creates a statement concerning the owner's personality.

source: openbmb/Ultra-FineWeb


The origin of the Rificolona lead back before twentieth century, when many peasants and mountain dwellers come to the city from the hills of Vallombrosa and Impruneta to celebrate the nativity of Madonna nella Basilica della Santissima Annunziata. They praised the Vergin 8 september and sold their products under the open Gallery of the Ospedale degli Innocenti.
To light the way during the walk, the peasants carrry small lanterns, open at the top to allow the candle to burn. This is an occasion when Florentine youngsters and teenagers party all night, teasing the peasants, calling them fierucolone or fieruculone, (on account of their animated participation and their rather abundant bottoms). Over the course of time, the party is a little changed but still today, on the night of the celebration, between 7 and 8 september, there are two groups: the boys march with their blowpipe and the children march in the city center supporting the rificolone and singing:
Ona, ona, ona
Oh che bella rificolona!
La mia l'è co' fiocchi
E la tua l'è co' pidocchi.
E l'è più bella la mia
Di quella della tu zia.
The word "rificolona" derives from the ancient "fierucola", little feast but important.


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On this page:
Definition of the noun algerian capital
What does algerian capital mean as a name of something?
- an ancient port on the Mediterranean; the capital and largest city of Algeria
- lexical domain: Locations - nouns denoting spatial position
- synonym of Algerian capital: Algiers
- instance of: port = a place (seaport or airport) where people and merchandise can enter or leave a country; national capital = the capital city of a nation
- part of: Algeria / Algerie / Democratic and Popular Republic of Algeria = a republic in northwestern Africa on the Mediterranean Sea with a population that is predominantly Sunni Muslim
Printed encyclopedias and other books with definitions for Algerian capital
Click on a title to look inside that book (if available):
Encyclopedia of World Trade (2015)
From Ancient Times to the Present by Cynthia Clark Northrup, Jerry H. Bentley, Alfred E. Eckes, Jr, Patrick Manning, Kenneth Pomeranz, Steven Topik
Algerian capital, Algiers. During.
Encyclopedia of Warfare (2013)
From the Earliest Times to the Present Day by Adrian Gilbert
area of the Algerian capital, Algiers, and from its warren of narrow streets and small houses carried out terrorist attacks in the European part of the city. In January 1957...
Online dictionaries and encyclopedias with entries for Algerian capital
Click on a label to prioritize search results according to that topic:
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Go to the usage examples of Algerian capital to see it in context!


text:
- a durable, lustrous, reversible fabric as of silk or linen, in figured weave, used for table linen, upholstery, etc.
- Damascus steel
- the wavy markings of such steel
- deep pink or rose
Origin of damaskItalian damasco, after Classical Latin Damascus (the city)
- Obs. of or from Damascus
- made of damask
- like damask
- deep-pink or rose
- to ornament with flowered designs or wavy lines
- to make deep-pink or rose
- A rich patterned fabric of cotton, linen, silk, or wool.
- A fine, twilled table linen.
- Damascus steel.
- The wavy pattern on Damascus steel.
transitive verbdam·asked, dam·ask·ing, dam·asks
- To damascene.
- To decorate or weave with rich patterns.
Origin of damaskMiddle English Damascus, damask from Latin Damascus from Greek Damaskos
(comparative more Damask, superlative most Damask)
- Relating to, or originating at, the city of Damascus.


this answer
Although it's nice to use OpenXML, this solution wont work on tables with colspans or rowspans without lots of work on the javascript generator – Eduardo Molteni Oct 11 '12 at 2:35
First, I would not recommend trying export Html and hope that the user's instance of Excel picks it up. My experience that this solution is fraught with problems including incompatibilities with Macintosh clients and throwing an error to the user that the file in question is not of the format specified. The most bullet-proof, user-friendly solution is a server-side one where you use a library to build an actual Excel file and send that back to the user. The next best solution and more universal solution would be to use the Open XML format. I've run into a few rare compatibility issues with older versions of Excel but on the whole this should give you a solution that will work on any version of Excel including Macs.
Open XML
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Excel has a little known feature called "Web queries" which let you retrieve data from almost every web page without additional programming.
A web query basicly runs a HTTP request directly from within Excel and copies some or all of the received data (and optionally formatting) into the worksheet.
After you've defined the web query you can refresh it at any time without even leaving excel. So you don't have to actually "export" data and save it to a file - you'd rather refresh the data just like from a database.
You can even make use of URL parameters by having excel prompt you for certain filter criteria etc...
However the cons I've noticed so far are:
 - dynamicly loaded data is not accessible, because Javascript is not executed
 - URL length is limited
Here is a question about how to create web queries in Excel. It links to a Microsoft Help site about How-To Get external data from a Web page
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mozilla still support base 64 URIs. This allows you to compose dynamically the binary content using javascript:
 download xls
if your excel file is not very fancy (no diagrams, formulas, macroses) you can dig into the format and compose bytes for your file, then encode them with base64 and put in to the href
refer to _URL_
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This code is IE only so it is only useful in situations where you know all of your users will be using IE (like, for example, in some corporate environments.)


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Women's and Gender Studies Clothesline Project
The Clothesline project is a participatory exhibit and a visual display that bears witness and attempts to break the silence surrounding violence against women and girls. The exhibit is comprised of t-shirts decorated to represent a particular woman's or girl's experience, by the survivor herself or by someone who cares about her, or cares about the issue. The shirts are hung on a clothesline for viewing. Participants walk through the rows of clothesline to bear witness to these tragedies. The project focuses on providing healing for survivors of violence, educating the public about violence, and preventing violence. The t-shirts on the clothesline were made by VSU students, faculty, staff and persons from the Valdosta community. The Clothesline is displayed each year in October, during Domestic Violence Awareness Month.

source: HuggingFaceFW/fineweb-edu


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Reflecting on UNISDR's reviews of the HFA, as well as GNDR's Views from the Frontline review of progress at the local level, this Reality Checklist highlights 10 essentials for local level impact.
Can we make sure that the HFA2 has an impact at the frontline?
We can enhance impact if we:
1. Understand local perspectives of risk
Listen and understand the experiences of people most at-risk
2. Consider the local context
Recognise the real life challenges of fragility, insecurity, and informality
3. Leave no one behind
Ensure the inclusion of all groups, particularly those most at-risk
Work with and across all groups and levels
5. Mobilise local resources
Build on existing capacities, knowledge and other sources of resilience
6. Align across policies
Ensure coherence across development and climate change activities
7. Hold people to account
Ensure accountability to local communities
8. Learn from the past and look to the future
Learn lessons and recognise future trends to inform recovery and development planning
9. Be environmentally aware
Recognise, protect and strengthen the functions of ecosystems
10. Recognise the potential of civil society
Actively work with civil society to achieve these essentials
How can I participate?
- In the run up to, during, and after the WCDRR in March, GNDR will be working to build support for these 10 essentials. In particular we want GNDR members to lobby with their national governments to utilise the checklist when designing their implementation plans. Share your stories of lobbying with governments on the GNDR Advocacy Facebook Group.
- Have a reality check with your partners. Use the Reality Checklist to develop and assess implementation strategies for the Post-2015 DRR Framework.


Colleges Soon Required to Give Students Access to Free Sluttery-Causing Birth Control
On Friday, the Obama administration released a 32-page document clarifying some rules about the Affordable Care Act's Preventative Care Mandate. Namely, since birth control is preventative care and since preventative care is required to be fully covered by employer-sponsored insurance, colleges and universities will also have to offer plans that give their students access to free birth control. Even religious schools. The girls are about to go so much more wild than you could possibly imagine.
Anticipating The Holy Stink Eye from The Holy See and others who think that it's an affront to their personal freedom when women associated with them are involved in crazy Magdalene-esque things like recreational sex or non-pregnancy, the President also offered a compromise that would remove conscientious oppressors from funding women's harlotry. Religious universities that object to paying for contraception would pass the cost onto the insurance company, just like religious employers.
Despite the administration's attempts to compromise, religious institutions have sued in recent months, claiming the contraception mandate requires them to finance things that they find morally objectionable. Religious institutions say that it's hypocritical for them to tell their students that birth control and premarital sex are morally objectionable and then offer no-cost birth control to their students. (Apt points, both, coming from a group that enjoys tax-exempt status while paying untold millions to the families of child victims that suffered sexual abuse at the hands of its employees.)
Complaining institutions are crying religious freedom, but what they really seen to want is for birth control to be as difficult and expensive to obtain as possible.
Religious academic institutions don't have to pay for the cost of contraceptive coverage — the administration says insurers must do that. So, to appeal to the year's most hilarious analogy, if contraception is like a ham sandwich and churches that object to contraceptives are like some Jewish people who object to ham, in this scenario, it's okay for nonbelieving students at the religious school to eat all the ham sandwiches they want, and they'll be financed by The Ham Sandwich Fund, which is not administered by the school. In fact, the ham sandwiches will likely be consumed in secret, and so no one will know who has chosen to eat ham sandwiches, because it's really not the University's business to know what students are eating. In fact, the university shouldn't blame the government for its students choosing ham sandwiches; rather, it should blame itself for having weak anti-ham sandwich arguments that fail to convince people to agree with them in the first place.
At the very least, the new law will save some girls in South Bend, Indiana a cab ride to the Planned Parenthood behind the car dealership just off Grape Road in Mishawaka.
New Rules for Health Plans [Inside Higher Ed]


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Danny and Katherine built a gorgeous house made of cob – a sustainable and natural material made from sand, clay, and straw. You'd never know that a house made from such material could be so beautiful!
source/image(PrtSc): Tiny House Giant Journey
Take a tour, learn how cob is made, and get inspired by this wonderful, debt-free family and their sustainable lifestyle. Watch the video from Tiny House Giant Journey for more info:
Cob, cobb or clom (in Wales) is a natural building material made from subsoil, water, fibrous organic material (typically straw), and sometimes lime. The contents of subsoil naturally vary, and if it does not contain the right mixture it can be modified with sand or clay.
Cob is fireproof, resistant to seismic activity,and uses low-cost materials, although it is very labour intensive. It can be used to create artistic and sculptural forms, and its use has been revived in recent years by the natural building and sustainability movements./wikipedia


Sayings of Dada J.P. Vaswani
Man's destiny is to be a divine bird, - to grow wings and fly from this world of darkness to the radiant world of light.
Know Thyself, - said Socrates. But no one Knows himself until he is opposed. Knowledge comes through conflict.
What is death? A gate to another life. To understand this is to be fearless.


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fall and spring candidates for directed teaching will spend at least 10 days in a school setting shadowing a teacher. This activity begins on the first day teachers return to school for pre-planning. The purpose for this experience is to provide insight into the procedures in the opening of school and everything that is involved in preparing for and receiving the students. These two weeks do not count toward the 550 hours of directed teaching. This activity is called the August Experience.
Directed Teaching/Seminar (4895—550 clock hours)
Candidates who successfully complete Methods Block II, as well as meet the additional program criteria, are admitted into Directed Teaching/Seminar and enroll in a 12-semester hour directed teaching culminating clinical experience. Directed Teaching involves a 550-clock hour, all day clinical experience over a 15 week period. Candidates work closely with both a university supervisor and a clinical supervisor in a classroom setting. Candidates are expected to perform all the duties and responsibilities of a veteran teacher, with a minimum of two weeks (10 days) of full-time, all day teaching.
For more information, please contact the Office of Field Experiences, William Hubbard Education Building, Room 307, or call _PHONE_.
Assessment measures used to assess candidate knowledge, skills, and dispositions are identified at each phase of the program and are presented in data tables in the Unit Assessment System.
The first transition point occurs when candidates enter Phase I, Entrance to the Teacher Education Program. In Phase I data collected from candidates include: GPAs, Georgia Assessments for the Certification of Educators (GACE) Basic Skills scores, pre-professional portfolios, interviews for entrance to the program, Regents' Exam, writing sample, background check, dispositions assessments, Pre-Professional Block courses and field experiences, letters of recommendation, proof of liability insurance, membership in a professional organization. Information from these sources combined with faculty observation, and performance in selected courses and activities allows the unit to determine if prospective candidates are prepared for study at the professional education level of the teacher education program.
These data are collected on an ongoing basis as requirements for entrance to the Teacher Education Program (just prior to the beginning of a candidate's junior year).
The second transition point occurs when candidates enter Phase II, Entrance to Clinical Practice (Directed Teaching). In Phase II data collected on candidates include GPAs, GACE Subject Assessment scores, dispositions assessments, interviews for directed teaching, and professional portfolios. These data determine if candidates meet the requirements for entrance to directed teaching.
These data are collected on an ongoing basis and are formally assessed at the beginning of a candidate's senior year.
The third transition point occurs when candidates enter Phase III, Exit from Clinical Practice (Directed Teaching). In Phase III data collected include GPAs, GACE Subject Assessment scores, professional portfolios, dispositions assessments, exit surveys, directed teaching evaluations and completion of the Teacher Education Program. Information from Phase III measures allows the unit to determine the extent to which candidates have mastered the identified outcomes of being competent in content, being competent in pedagogy, possessing a caring disposition, appreciating diversity, and being skilled in the use of technology at the level of proficient educators.
These data are collected on an ongoing basis and are formally collected/assessed at the end of a candidate's senior year. They are a requirement for a recommendation for completion of the Teacher Education Program and for certification.
The fourth transition point occurs when graduates enter Phase IV, Entrance to the Profession. In Phase IV data collected include Graduate Surveys, Employer Surveys, and Alumni Surveys. Information from Phase IV measures allows the unit to determine the extent to which graduates have mastered the identified outcomes.
These data are collected at the end of a graduate's first year of teaching.
The progress of all students who are admitted into or are applying for admission into any initial or advanced program is monitored from the point of entrance to the program until they exit the program and enter the profession. This scrutiny begins in the first two years when candidates are enrolled in introductory education courses. It continues as candidates are admitted to the Teacher Education Program. Included are multiple assessments at four major Phases (transition points) in the program. A full description of the assessments used is included in the Unit Assessment System. The table below outlines the transition points and examples of assessments for each:
Transition Points (Phases) and Assessments – Initial Program
Phase I – Entrance to the Teacher Education Program
(Should be completed by the beginning of junior year)
- 2.70 or better GPA
- Georgia Assessments for the Certification of Educators (GACE) Basic Skills
- Pre-professional electronic portfolio
- Successful interview and presentation
- Background Check
- Satisfactory ratings on Dispositions Assessments
- Satisfactory completion of Pre-Professional Block
- Satisfactory completion of Educator Ethics – Program Entry (350)
Block courses and field experiences
- Acceptable Letters of Recommendation (3)
- Proof of Liability Insurance
- Membership in Professional Organization (GAESP, SPAGE or NAAE)
Phase II – Entrance to Clinical Practice
(Directed Teaching – Should be completed by beginning of senior year)
- 2.90 or better GPA
- Georgia Assessments for the Certification of Educators (GACE) Subject Assessment
- Satisfactory Ratings on Dispositions Assessments
- Interviews for Directed Teaching
- Development of Professional Electronic Portfolio
- Educator Ethics – Program Exit (360)
Phase III – Exit from Clinical Practice
(Directed Teaching/Exit from Program – Should be completed by end of Senior Year)
- 2.90 or Better GPA
- Georgia Assessments for the Certification of Educators (GACE) Subject Assessment
- Professional Portfolio
- Dispositions Assessments
- Exit surveys
- Directed Teaching Evaluations
- Completion of the Teacher Education Program
Phase IV Entrance to the Profession
(Should be completed at the end of a graduate's first year of teaching)
- Graduate Surveys
- Employer Surveys
- Alumni Surveys


Center for Global Change Science 2014-07-14T17:37:05Z The Mercury Game: Evaluating a Negotiation Simulation that Teaches Students about Science–Policy Interactions The Mercury Game: Evaluating a Negotiation Simulation that Teaches Students about Science–Policy Interactions Stokes, Leah C.; Selin, Noelle E. Environmental negotiations and policy decisions take place at the science–policy interface. While this is well known in academic literature, it is often difficult to convey how science and policy interact to students in environmental studies and sciences courses. We argue that negotiation simulations, as an experiential learning tool, are one effective way to teach students about how science and policy interact in decision-making. We developed a negotiation simulation, called the Mercury Game, based on the global mercury treaty negotiations. To evaluate the game, we conducted surveys before and after the game was played in university classrooms across North America. For science students, the simulation communicates how politics and economics affect environmental negotiations. For environmental studies and policy students, the mercury simulation demonstrates how scientific uncertainty can affect decision-making. Using the mercury game as an education tool allows students to learn about complex interactions between science and society and develop communication skills. 2014-01-01T00:00:00Z The Future of Global Water Stress: An Integrated Assessment The Future of Global Water Stress: An Integrated Assessment Schlosser, C. Adam; Strzepek, Kenneth M.; Gao, Xiang; Gueneau, Arthur; Fant, Charles; Paltsev, Sergey; Rasheed, Bilhuda; Smith-Greico, Tony; Blanc, Elodie; Jacoby, Henry D.; Reilly, John M. We assess the ability of global water systems, resolved at 282 large river basins or Assessment Sub Regions (ASRs), to the meet water requirements over the coming decades under integrated projections of socioeconomic growth and climate change. We employ a Water Resource System (WRS) component embedded within the MIT Integrated Global System Model (IGSM) framework in a suite of simulations that consider a range of climate policies and regional hydroclimatic changes through the middle of this century. We find that for many developing nations water-demand increases due to population growth and economic activity have a much stronger effect on water stress than climate change. By 2050, economic growth and population change alone can lead to an additional 1.8 billion people living in regions with at least moderate water stress. Of this additional 1.8 billion people, 80% are found in developing countries. Uncertain regional climate change can play a secondary role to either exacerbate or dampen the increase in water stress due to socioeconomic growth. The strongest climate impacts on relative changes in water stress are seen over many areas in Africa, but strong impacts also occur over Europe, Southeast Asia and North America. The combined effects of socioeconomic growth and uncertain climate change lead to a 1.0 to 1.3 billion increase of the world's 2050 projected population living in regions with overly exploited water conditions— where total potential water requirements will consistently exceed surface-water supply. Under the context of the WRS model framework, this would imply that adaptive measures would be taken to meet these surface-water shortfalls and would include: water-use efficiency, reduced and/or redirected consumption, recurrent periods of water emergencies or curtailments, groundwater depletion, additional inter-basin transfers, and overdraw from flow intended to maintain environmental requirements. 2014-01-01T00:00:00Z An Analogue Approach to Identify Extreme Precipitation Events: Evaluation and Application to CMIP5 Climate Models in the United States An Analogue Approach to Identify Extreme Precipitation Events: Evaluation and Application to CMIP5 Climate Models in the United States Gao, Xiang; Schlosser, C. Adam; Xie, Pingping; Monier, Erwan; Entekhabi, Dara Global warming is expected to alter the frequency, intensity, and risk of extreme precipitation events. However, global climate models in general do not correctly reproduce the frequency and intensity distribution of precipitation, especially at the regional scale. We present an analogue method to detect the occurrence of extreme precipitation events without relying on modeled precipitation. Our approach is based on the use of composites to identify the distinct large-scale atmospheric conditions associated with widespread outbreaks of extreme precipitation events across local scales. The development of composite maps, exemplified in the South-Central United States and the Western United States, is achieved through the joint analysis of 27-yr (1979–2005) CPC gridded station data and NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA). Various circulation features and moisture plumes associated with extreme precipitation events are examined. This analogue method is evaluated against the MERRA reanalysis with a success rate of around 80% in detecting extreme events within one or two days. When applied to the climate model simulations of the 20th century from Coupled Model Intercomparison Project Phase 5 (CMIP5), we find the analogues from the CMIP5 models produces more consistent (and less uncertain) total number of extreme events compared against observations as opposed to using their corresponding simulated precipitation over the three regions examined. The analogues also perform better to characterize the interannual range of extreme days with the smaller RMSE across all the models for all the descriptive statistics (minimum, lower and higher quartile, median, and maximum). These results suggest the capability of CMIP5 models to simulate the realistic large-scale atmospheric conditions associated with widespread local-scale extreme events, with a credible frequency. Collectively speaking, the presented analyses clearly highlight the comparative and enhanced nature of these results to studies that consider only modeled precipitation output to assess extreme-event frequency. 2013-11-01T00:00:00Z Synergy between Pollution and Carbon Emissions Control: Comparing China and the U.S. Synergy between Pollution and Carbon Emissions Control: Comparing China and the U.S. Nam, Kyung-Min; Waugh, Caleb J.; Paltsev, Sergey; Reilly, John M.; Karplus, V.J. We estimate the potential synergy between pollution and climate control in the U.S. and China, summarizing the results as emissions cross-elasticities of control. We set a range of NOx and SO2 targets, and record the ancillary reduction in CO2 to calculate the percentage change in CO2 divided by the percentage change in NOx (SO2) denoted as ECO2,NOx (ECO2,SO2). Then we conduct the opposite experiment, setting targets for CO2 and recording the ancillary reduction in NOx and SO2 to compute ENOx,CO2 and ESO2,CO2. For ECO2,NOx and ECO2,SO2 we find low values (0.06‒0.23) in both countries with small (10%) reduction targets that rise to 0.40‒0.67 in the U.S. and 0.83‒1.03 in China when targets are more stringent (75% reduction). This pattern reflects the availability of pollution control to target individual pollutants for smaller reductions but the need for wholesale change toward non-fossil technologies when large reductions are required. We trace the especially high cross elasticities in China to its higher dependence on coal. These results are promising in that China may have more incentive to greatly reduce SO2 and NOx with readily apparent pollution benefits in China, that at the same time would significantly reduce CO2 emissions. The majority of existing studies have focused on the effect of CO2 abatement on other pollutants, typically finding strong cross effects. We find similar strong effects but with less dependence on the stringency of control, and stronger effects in the U.S. than in China. 2013-10-01T00:00:00Z


text:
Thomas Hockenhull, curator, British Museum
The 2008 banking crisis plunged the UK into a recession from which it has been struggling to recover ever since. However, this crisis is not the first to have affected Britain and it is unlikely to be the last. Here in the Department of Coins and Medals we decided to look at the bigger picture in an exhibition looking back at Britain's financial crises since the 1700s.
Drawing upon our extensive collection, we found we had an object that related to almost every crisis to affect Britain since the advent of organised banking. This material ranged from share certificates for companies that failed and notes from failed banks, to reports and recriminations about crises. In some cases these objects are fragile and sensitive to light, meaning that they can never go on permanent display.
For the rest of the exhibition we wanted to show how ordinary people have, and will continue, to respond to financial crisis. Numerous cartoons and satirical prints have been produced over hundreds of years relating to crises, including a James Gillray print from 1797.
Additionally, the artist Steve Bell – perhaps best known for his work in The Guardian newspaper – has loaned a work from 2011 entitled 'Bank Levy' that depicts a banker as a distraught fat cat in a suit having its claws clipped by the Chancellor George Osborne.
Other exhibits, for example, include a champagne bottle given out by Northern Rock to its employees when the Building Society demutualised to become a bank in 1997. This object was retained by its recipient, a former employee, and provides an ironic reminder that demutualisation was greeted optimistically, supposedly enabling Northern Rock to expand its business more easily.
Instead, history records that its investment portfolio would fail within 10 years, triggering the first run on a UK bank since that which occurred during the collapse of Overend, Gurney and Co. in 1866.
The collapse of Overend, Gurney and Co. features elsewhere in the exhibition and, in both instances the banks failed because their customers lost faith in their ability to protect and reinvest their savings.
The centrepiece of the exhibition is a contemporary sculpture by Justine Smith, a London-based artist. Made from real UK banknotes built into a house of cards, the artwork neatly symbolises the occasionally precarious nature of financial investment.
I hope many people will get a chance to come and see the display, to find out how 300 years of boom and bust have helped to shape Britain's financial landscape.


text:
During this pandemic, eyes have been opened on the impact we have had on the planet. Images are circulating of the City of Los Angeles before quarantine and after a few weeks of quarantine. The hazy smog over the city lifted after just a few weeks. This shows how resilient our planet is at clearing the mess we as humans have inflicted upon it. Nausicaä of the Valley of the Wind is set in a post-apocalyptic earth, devastated by pollution. Princess Nausicaä is a pacifist who struggles to stop two warring kingdoms from destroying the planet along with themselves.
Despite knowing the consequences of taking her mask off, Princess Nausicaä (Allison Lohman) reflects on the beauty of the spores that float around her. Once she lifts the eye casing off the dead Ohm, she puts it over her head to continue watching the spores. The mask looks like an insect face in addition to keeping her safe from the toxic air. She is interrupted by the sound of someone in trouble. While investigating, she sees that an adult Ohm is chasing Lord Yupa (Patrick Stewart). The scene is complemented by excellent chase music. Nausicaä is calm and notices the beauty in the giant insect despite the dangerous situation they are in. Another scene Nausicaä lands on a group of insects and apologizes for disturbing them. She understands that while she can navigate their world in the forest; it is still their world while the Valley of the Wind is hers.
The Ohm's eyes reflect their emotional state. When an Ohm is enraged and defensive, its eyes are red. Once the Ohm calms down, the eye color changes to the color of harmony and stability, greenish-blue. The villagers know this, stating in several scenes that the Ohm are blind with rage. When Nausicaä returns with the eye casing of the Ohm, the villagers get the rest of the creature; it is used as a resource for building and creating. The forest may be toxic, but they rely on the resources and warn the warring Tolmekian and Pejite against disrupting the delicate balance that they have with the toxic forest and its inhabitants.
Before the Tolmekian army takes Nausicaä, Lord Yupa finds her in a hidden garden below the castle. She brings samples when she explores the toxic forest and grows them in the castle. From her experiments, she learns they are no longer poisonous and the air in the castle remains clean. She tells Lord Yupa that she discovered the freshwater and soil from deep beneath the castle is what separates her plants from the ones in the forest. The topsoil is toxic, and the deep soil is not.
Nausicaä and Asbel (Shia LaBeouf) sink in the 80's films number one natural enemy, quicksand. They fall deep beneath the toxic forest, and to their surprise, the air is clean. After investigating, Nausicaä concludes that the trees die, petrify, crumble, and turn into sand. It is the sand that filters and cleanses the earth, which is why the deep soil is not toxic. The area they fell into was formed from the trees dying fossilizing and turning into sand. Asbel notes that it would take centuries for the trees to purify and cleanse the entire earth due to all the pollution the humans have done. The insects protect forests from any more human intervention and are necessary for life to continue at all.
In her rage after the invading Tolmekian's murder of her father, she kills some men to avenge her father's death. After this, she is left feeling guilty and attempts to stop the killing, which nearly gets Nausicaä killed. A baby Ohm is used to bait an angry stampede of Ohm to come and destroy the Valley of the Wind to evoke a plan to destroy the toxic forest and the insects that live in it. She risks her life to take a stolen baby Ohm to a stampede of Ohm to save her village. When the Ohm lifts her into the air to heal her from her injuries, a section of Handel's "Music for the funeral of Queen Mary" is playing, fitting for a princess.
Drenched in the blue blood of the Ohm, she is lifted by their gold glowing tentacles. This image of her solidifies to Nausicaä's aunt, Obaba (Tress MacNeille), that she is the fulfillment of the prophecy to save the humans. With Nausicaä's gentle leadership and demonstration to the onlookers of all the kingdoms, even the most volatile creature can be stopped by compassion and understanding. Once we can understand our monsters, they stop being monsters. When we stop seeing things as monsters, we can value life regardless of its form.


I am looking at servos to make a robot claw, and I want to make sure the one i am getting can turn under a specific amount of weight. The servos specify their torque in oz-in. I am not sure how to read this.
What i need to know is, how to I convert oz-in into the specific weight it can withstand in lbs.
If you are not familiar with the unit of measurement:
1 oz-in = 0.00706 Nm
if you are not familiar with torque:
1 Nm torque translates to 1N of force at a radial distance from the shaft of the motor of 1 m. As 1N gravitational force corresponds to an approx. 0.1kg weight, 1 Nm torque can lift* 0.1kg weight 1m away from the shaft, or 1 kg weight 0.1m away from the shaft.
*Lift in this case means that if such weight is attached to the rotor, the rotor would be in equilibrium, less weight then this would start to rotate.
 - $\begingroup$ So, if i had a length of 2M with 1Nm, would that make 0.5N? _USER_ $\endgroup$ – X Builder Oct 21 '20 at 22:54
 - $\begingroup$ exactly, 2m radial distance, 0.5N $\endgroup$ – 50k4 Oct 21 '20 at 23:06
Your Answer


Common Protein Analysis Methods to New Developments
Originally Published: November 21, 2014
Last Updated: March 3, 2021
Common protein analysis methods to new developments.
November 21, 2014 – Protein is vast and complicated and, as such, needs equally complex methodologies to analyze it. Joe Katzenmeyer, Chemistry Supervisor of rtech Labs, provided a crash course on common protein analysis methods to new developments used in determining protein quality.
"I like to tell people that the work my lab does bridges the gap between very traditional technology and very modern technology," Katzenmeyer said, adding that his lab analyzes between 1,500-2,000 protein samples per month.
On the traditional side, there's the Kjeldahl Method, which has evolved quite a bit since 1883 and is still widely used. In it, samples are boiled in sulfuric acid to convert the nitrogen into ammonium sulfate. The distillation involves adding sodium hydroxide and steam heat to release the nitrogen as ammonia; then the ammonia is captured in a boric acid solution that is titrated with hydrochloric acid.
"The majority of our work is done by this method. In a good day, we have two shifts that can run about 10 racks of samples," Katzenmeyer said. "It's our most high-throughput method and the most commonly used for nutritional labeling."
The Dumas Method is another traditional technique for protein analysis that involves the combustion of the sample and collection of the resulting gases. It involves far fewer chemicals and far less time than Kjeldahl, which is increasing its popularity, Katzenmeyer said. It involves applying high heat in a pure oxygen atmosphere; collecting gases; removing carbon dioxide and water; and analyzing the remaining nitrogen with a thermal-conductivity detector.
Both the Dumas and Kjeldahl methods are highly precise, with easily comparable results, but they have some obvious drawbacks. Non-protein nitrogen can be interpreted as protein, so one doesn't know which proteins are involved, and one needs a multiplication factor to turn the nitrogen content data into protein.
More modern methodologies rectify those issues, and separation systems have been developed to determine the presence and amount of non-protein nitrogens and individual proteins, such as myoglobin, denatured/undenatured whey, casein and alpha-lactalbumin.
Gel electrophoresis, for instance, uses electricity to separate and quantify protein macromolecules and fragments based on their size and charge. Liquid chromatography is another example, which takes liquid proteins (often dairy) and passes them through a column for the same purpose.
There is also mass spectrometry, which ionizes the components of a sample with an electron beam and then separates them with electromagnetic fields.
Of the more recent methods, however, near-infrared reflectance is most on the rise because of its incredible speed. It uses an infrared light directed at the sample, which causes vibrations in the chemical bonds and creates an energy spectrum that is analyzed and calibrated. "You could have a protein content reading on the production line in, say, 30 seconds," Katzenmeyer added.
These recently developed methods, while more informative and specific, are generally more costly to execute. "They don't separate very well, which is the difficulty with proteins. Imagine you have 10,000 proteins—you can't fit all those peaks [one for each protein] in one little window. So, it gets much more complicated; more labor-intensive; and more expensive," Katzenmeyer said.
Joseph Katzenmeyer, Chemistry Supervisor of rtech Laboratories,, _PHONE_
The summary above is an excerpt from the "2014 Protein Trends & Technology Seminar Magazine: Formulating with Proteins."
Tags: Nutrition
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does the above code look like? It looks like ordinary imperative synchronous code. Read this value, then read this value, then read this value. Except it's not synchronous, and it's not imperative. It's functional and asynchronous. We've taken our building blocks, and composed them into a piece of very readable code that makes it completely clear exactly what we are doing.
Now in case you're not 100% sure about the above syntax, the values to the left of the <- signs are the results of the iteratees to the right. These are able to be used anywhere in any subsequent lines, including in the end yield statement. Underscores are used to say we're not interested in the value, we're using this for the expect iteratee since that just returns Unit anyway. The statement after the yield is a map function, which gives us the opportunity to take all the intermediate values and turn them into a single result.
So now that we understand that, let's rewrite our quoted iteratee to support escaped quotes. After reading our quote, we want to peek at the next character. If it's a quote, then we want to append the value we just read, plus a quote to our cumulated value, and recursively invoke the quoted iteratee again. Otherwise, we've reached the end of the value.
def quoted(value: Seq[Char] = IndexedSeq[Char]()): Iteratee[Char, String] = for {
 _ <- expect('"')
 maybeValue <- takeWhile(_!= '"')
 _ <- expect('"')
 nextChar <- peek
 value <- nextChar match {
 case Some('"') => quoted(value ++ maybeValue :+ '"')
 case _ => Done[Char, String]((value ++ maybeValue).mkString)
} yield value
Now we need to write an iteratee that can parse either a quoted or unquoted value. We choose which one by peeking at the first character, and then accordingly returning the right iteratee.
def value = for {
 char <- peek
 value <- char match {
 case Some('"') => quoted()
 case None => Error[Char]("Premature end of input, expected a value", Input.EOF)
 case _ => unquoted
} yield value
Let's now parse an entire line, reading until the end of line character.
def values(state: Seq[String] = IndexedSeq[String]()): Iteratee[Char, Seq[String]] = for {
 _ <- dropSpaces
 value <- value
 _ <- dropSpaces
 nextChar <- takeOne
 values <- nextChar match {
 case Some('\n') | None => Done[Char, Seq[String]](state :+ value)
 case Some(',') => values(state :+ value)
 case Some(other) => Error("Expected comma, newline or EOF, but found " + other, Input.El(other))
} yield values
Now, in a similar way to how we parse the values, we could also parse each line of a CSV file until we reach EOF. But this time we're going to do something a little different. We've seen how we can sequence iteratees using flatMap, but there are further possibilities for composing iteratees. Another concept in iteratees is enumeratees. Enumeratees adapt a stream to be consumed by an iteratee. The simplest enumeratees simply map the input values of the stream to be something else. So, for example, here's an enumeratee that converts a stream of strings to a stream of ints:
def toInt: Enumeratee[String,Int] =[String](_.toInt)
One of the methods on Enumeratee is transform. We can use this method to apply an enumeratee to an iteratee:
val someIteratee: Iteratee[Int, X] =...
val adaptedIteratee: Iteratee[String, X] = toInt.transform(someIteratee)
This method is also aliased to an operator, &>>, and so this code below is equivalent to the code above:
val adaptedIteratee: Iteratee[String, X] = toInt &>> someIteratee
We can also make an enumeratee out of another iteratee, and this is exactly what we're going to do with our values iteratee. The Enumeratee.grouped method takes an iteratee and applies it to the stream over and over, the result of each application being an input to feed into the the iteratee that will be transformed. Let's have a look:
def csv = Enumeratee.grouped(values())
Now let's get a little bit more creative with enumeratees. Let's say that our CSV file is very big, so we don't want to load it into memory. Each line is a series of 3 integer columns, and we want to sum each column. So, let's define an enumeratee that converts each set of values to integers:
def toInts =[Seq[String]](
And another enumeratee to convert the sequence to a 3-tuple:
def toThreeTuple =[Seq[Int]](s => (s(0), s(1), s(2)))
And finally an iteratee to sum the them:
def sumThreeTuple(a: Int = 0, b: Int = 0, c: Int = 0): Iteratee[(Int, Int, Int), (Int, Int, Int)] = Cont {
 case Input.El((x, y, z)) => sumThreeTuple(a + x, b + y, c + z)
 case Input.Empty => sumThreeTuple(a, b, c)
 case in @ Input.EOF => Done((a, b, c), in)
Now to put them all together. There is another method on enumeratee called compose, which, you guessed it, let's you compose enumeratees. This has an alias operator, ><>. Let's use it:
Finally, if an iteratee consumes a stream, what produces a stream? The answer is an enumerator. An enumerator can be applied to an iteratee using its apply method, which is also aliased to >>>. This will leave the iteratee in a cont state, ready to receive more input. If however the enumerator contains the entirety of the stream, then the run method can be used instead which will send the iteratee an EOF once it's finished. This is aliased to |>>>.
The Play enumerator API makes it easy to create an enumerator by passing a sequence of inputs to the Enumerator companion objects apply method. So, we can create an enumerator of characters using the following code:
val csvFile = Enumerator(
And we can feed this into our iteratee like so:
val result = csvFile |>>> processCsvFile
And our result in this case will be a future that is eventually redeemed with (5, 7, 9).
Well, it's been a long journey, but hopefully if you're an imperative programmer, you not only understand iteratees, you understand the reasoning behind their design, and how easily they compose. I also hope you have a better understanding of both functional and asynchronous programming in general. The functional mindset is quite different to the imperative mindset, and I'm still getting my head around it, but particularly after seeing how nice and simple iteratees can be to work with (once you understand them), I'm becoming convinced that functional programming is the way to go.
If you are interested in downloading the code from this blog post, or if you want to see a more complex JSON parsing iteratee/enumeratee, checkout this GitHub project, which has a few examples, including parsing byte/character streams in array chunks, rather than one at a time.


_USER_ {13591, title = {Logo Retrieval in Document Images}, booktitle = {Document Analysis Systems}, year = {2012}, month = {2012///}, abstract = {This paper presents a scalable algorithm for segmentation free logo retrieval in document images. The contributions of this paper include the use of the SURF feature for logo retrieval, a novel indexing algorithm for efficient retrieval of SURF features and a method to filter results using the orientation of local features and geometric constraints. Results demonstrate that logo retrieval can be performed with high accurately and efficiently scaled to a large datasets.}, author = {Jain,Rajiv and David Doermann} }


text:
Elicitation of Diagnosis Strategy During Scanning Chest X-Rays from Eye Tracking Stimulated Retrospections
Authors: Hirotaka Aoki, Koji Morishita, Marie Takahashi, Rea Machida, Kousuke Hirata, Atsushi Kudoh, Tsuyoshi Shirai
Abstract: In the present paper, we apply a debriefing technique aided by eye movement recordings to elicitation of clinical reasoning processes during chest x-rays diagnosis. It can be expected that this technique allows us to obtain elaborated information regarding hidden cognitive processes compared to conventional verbal protocol approach. Two experiments where medical tasks of 20 medical doctors (10 majoring in radiology/ respiratology and 10 majoring in surgery/acute medicine) on diagnosis of chest x-rays images were recorded with a video camera and an eye tracking system were performed. In the first experiment, each one of 5 chest x-rays having four patterns of cancer, pneumonia, normal and others were shown. A participant was asked to make his/her diagnosis decisions about whether each of chest x-rays. Immediately afterwards, a debriefing where each eye tracking recording was used as a cue to verbalize the participant's implicit diagnosis processes was conducted. In the second experiment, a comparative diagnosis on the current patient's status was carried out. Five pairs of x-rays images were shown to each participant. In each pair, one was a current image and the other one was an image taken a year ago. The participant examined the current patient's status by identifying small changes with time. The debriefing stimulated by eye movement recordings was performed just after the task. Based on the verbal protocols form the debriefing session, each participant's reasoning processes were traced. The results indicated that there were mainly four effective reasoning strategies as followings: Postponement of lung field interpretation, avoidance of preconception by applying redundant scanning rule, critical area revisited, and complying with one's mental check-list at any moment. At the same time, one problematic strategy was also identified that can be named as "single lesion focusing strategy." Based on all results as well as implications obtained, we discuss insights relating to effective medical reasoning processes as well as validity of verbal protocols/comments on eye mark recordings.
Keywords: Expertise analysis, clinical reasoning process, chest x-rays, debriefing using eye movement recording
Cite this paper:


text:
this information, I'm not sure if the program will accept reference changes at all
You can edit references in the reference area (which is pink by default). You can safely delete reference fields, but you need to decide if that change should be local (for that element only) or global (for all elements using this reference). You will not be able to delete _TAG_ or _TAG_ fields because they are added automatically to references (not being a part of reference). You can freely change the text of references. Illegal changes are all changes that do not comply with the reference format, e.g. lines that do not start with reference field tags, or lines that start with unknown reference field tags (e.g. _TAG_). If you are unsure how this process works, import a single article from Wikipedia to a newly created collection, create some extracts and play with editing to see how references are processed.
Should items be
converted to plain text in the end?
(marjur, Oct 29, 2009, 20:51:00)
Once fully processed, do you recommend changing ready items from HTML into plain text?
Plain text takes much less space. Your collections will be faster to back up. All you need to make sure is that HTML does not contain information that may be needed to effectively remember the item (e.g. is the context fully retained once references are removed)? In the long run, simple plain text items might do their work better by depriving you of additional cues as to the correct answer. However, you will always get the best answer to your question by simply experimenting on your material. Leave some of your items as HTML and convert some to plain text. After some time you will probably have your own conclusions and preferences.
You can make cloze
deletion keyword styles invisible
(jm lopez, Wednesday, November 24, 2010 9:33 PM)
Is there any way to turn off marking words in the clozed deletion? In 2001, I found the following FAQ: Currently you cannot customize cloze deletion behavior. In the future, cloze formats are likely to be customizable. That was 9 years ago, and I could not read any documentation that made the statement clearer.
You can turn off cloze deletion styles using stylesheets. Note, however, that those markings are vital for efficient processing of topic extracts. If you turn off the markings, you will effectively disable incremental reading. If you would like to turn off the markings only in generated cloze deletions, you can use a separate template for generated cloze deletitions that would use styles with invisible cloze styles. In the future, SuperMemo will remove cloze keyword marking from cloze deletions, while leaving them in the processed topic. This will allow of applying incremental reading without generating "unclean" looking clozes
A-Factors can be
(Henrik, Thursday, May 26, 2011 22:16)
What is your recommended strategy for assigning A-Factors?
Now that you have a priority queue, A-Factors are best left unattended. In items, A-Factors play an important role in the learning algorithm and cannot be changed. However, in topics, the main function of A-Factors is to determine the speed at which the material is getting diluted in incremental reading. For most important articles, you will probably set the next interval manually and thus ignore the A-Factor altogether. For the remaining articles, speed of dilution is of less concern. The sequence of learning is determined by topic priority. Low-priority topics with high A-factors will simply be slightly less likely to be subject to review than topics with lower A-Factors
Is it possible to read PDF articles
(Karolina, Poland, Nov 21, 2011, 13:57:39)
Is it possible to read PDF articles incrementally?
You cannot import PDF to HTML components, unless you convert them to HTML (or plain text) first. Alternatively, you can copy and paste from Acrobat to SuperMemo, however, Acrobat will not let you do multipage selections that would paste fast and nicely. Some PDF documents do not even allow of selecting texts. If you want to work incrementally, you can use an alternative strategy:
Cloze deletions work on topics (not on items)
(Benoit, France, Sat, 25 Feb 2012 15:05:28 +0100 (CET))
I have a problem with clozed questions. I click on Add New, then I select a word, click on the "T" or "Alt+Z". But it doesn't work. Logically, the word selected after having pressed "Alt+Z" should be missing in the question and present in the answer. But in the answer I can only see "_TAG_" or "_TAG_" and the word selected is still in the question.
Add New should be used for adding items, while cloze deletion works on topics. You have two choices:
After you execute Cloze deletion, you will not see the cloze (because its appearance is obvious from the shape of the topic). Instead, to save time, you will remain in your topic ready for generating more cloze deletions.
Conglomerating information in spaced repetition results in slower learning
(L.S., Nov 09, 2012, 11:04:45)
I tend to disagree with some of your "20 rules claims". For example,
Q: What was decided at the Council of Trent, beginning in 1545, and how long did the Council go on? A: The basic beliefs of the Catholic Church; 18 years.
Mixing two questions in one is more efficient and also links related pieces of information together that should be linked together. It is more effortful to remember the answers, I agree, and that is a concern. Occasionally I'll rewrite or simplify a question, or break it into two, if it becomes too difficult.
E.g., asking what the Council of Trent was and how long it went on makes sense because they are both very basic questions about the Council of Trent. If I were to separate them, the neurons wouldn't fire together. It would take a little extra effort to discover that the thing that formed the basic beliefs of the Catholic Church lasted for 18 years. Since he'll be learning both facts at about the same time, why not learn them together?
In the same way, contrary to your advice (sorry!), I do still have full sentence and even two-sentence questions--only occasionally. But the point is that sometimes, the thing that needs to be committed to memory is a narrative, a whole sequence of events and not just particular items from the sequence. Maybe I am wrong, but I think a narrative is best remembered by practicing the narrative.
Two separate memories should be separated in SuperMemo due to the fact that they nearly always will require different timing of repetitions. If you can always activate the same mental pathway in thinking about the Council of Trent ("neurons firing together" in the same pattern), your particular item has a good chance of surviving long in the process without a memory lapse. However, once you build a large database of similar items, and you review your sizeable material under the pressure of time, your review will always tend to strip redundant pieces of information. Overtime, your nice item will be reduced to the bare bones of information that will often fail its primary test: applicability in real life. It may happen, that despite zero memory lapses, in 2-3 years, someone will ask you about a Council of Trent in a new context and you will be amazed that you won't be able to reasonably answer the question despite having all the necessary pieces of information included in your item. Two memories of different difficulty might be compared to two different planes of different flying characteristics. The difficult piece (e.g. 18 year duration of the Council) might be compared to a slow flying plane. The easy piece (here the reference to the Catholic Church) might be compared to a modern jet. Review of the conglomerated item might be compared to flying both planes at the same speed. In an extreme case, this might be impossible. The compromise speed might be too high for a slow plane, which might disintegrate beyond a certain speed limit, while the faster plane cannot slow down enough without stalling. In our memory, forgetting is equivalent to forgetting, while stalling is caused by the spacing effect. By doing complex and repeatable reasoning at each repetition, you might act as if handling both planes using remote control. However, this is always difficult and requires lots of focus and deliberation at repetitions. Your brain has natural defenses against such "enforced repetitive reasoning". It is designed to be "intellectually lazy" and thus energetically efficient. Practice shows that incremental reading produces many more items. However, those items are usually much easier to remember. In the end, you spend less time on reviewing 5-10 items than you would spend on an item that would conglomerate information and suffered repeated memory lapses or very short intervals.
In the course of the evolution, the brain developed strategies for abstracting away from the details and retaining only the most essential, useful and frequently used information. Those strategies are great for survival, but aren't as good in reaching our educational goals. Council of Trent is a typical example of knowledge we wish to have, but that is pretty expensive. This is because, for most people, it does not get reinforced in run-of-the-mill conversations, TV shows, daily applicability, or at water cooler at work. The situation might differ if you, in particular, read a lot on the subject matter. This might help the memory establish itself in an efficient manner. Incremental reading makes it possible to root such difficult


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Daily 9x9 Nurikabe for 2013-08-20
Nurikabe is a binary determination puzzle. You must decide for each cell if it is white or black (by clicking on them) according to the following rules:
- All of the black cells must be connected.
- Each numbered cell must be part of a white island of connected white cells.
- Each island must have the same number of white cells as the number it contains (including the numbered cell).
- Two islands may not be connected.
- There cannot be any 2x2 blocks of black cells.
Read more about the history and methods behind nurikabe in the Wikipedia nurikabe article.


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Guide to buying the Perfect Mattress
To obtain a child mattress does not require very expensive mattresses since children are light, not exerting much force on the mattress. Also, it is necessary to remember that these mattresses need to be changed in a short time due to the natural growth of the child.
When to change the Mattress
It is advisable to replace the mattress every ten years because it is normal to have an accumulation of viruses, bacteria, and trillions of mites, which favor respiratory problems and allergy, including the skin.
It is also recommended to change whenever you think the mattress is dirty or when it already has the shape of your body. However, you can flip the mattress once a year to lessen the risk of the mattress being marked.
Know the Best Mattress and Pillow for You to Sleep Better
An incorrect pillow can cause headache, neck or spine and so your choice is just as important as the mattress. So, to choose a suitable pillow should visit sleepjunkie.online.
- Lie down and check that the spine and neck are aligned and straight;
- Inform yourself about pillow materials, whether they are biodegradable or if they contain antimicrobial tissue that prevents the development and buildup of fungi and bacteria;
- If you sleep on your side, you need a medium or high pillow, if you sleep on your belly up, on a low or medium pad, and you sleep on your stomach you do not need a pad.
- As with the mattress, the proper pillow should not be too high or too low and should be the ideal height to ensure that the neck is straight. It is essential that the cushion helps to align the spine so that it is not bent, so some orthopedic pillows have a small curvature, which serves to support the neck well.


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Fostering an ecological worldview: What's love go to do with it?
Despite the growth of interest in nature based leisure pursuits, including ecotourism, there is little understanding of the environmental orientation of those who are more interested in nature based leisure experiences when compared with those who are not. This research sought to gain deeper insights into the psychological profile of the person who prefers nature based leisure activities, such as ecotourism, over other types of leisure activities by extending existing models of pro-environmental altruism (conceptualised as an ecological worldview) and incorporating a new and explicitly emotional construct of love and care for nature. This construct, variously termed 'biophilia' or a 'land ethic', has not been previously measured in spite of its apparent importance in the development of an environmental ethic. In order to achieve the aims of this research a psychometrically sound scale that measured the construct of love and caring for nature was developed. The development process, involving 568 respondents, led to a final scale that exhibited good psychometric properties, including high reliability and good content, criterion-related, and construct validity. The findings of this research show that an ecological worldview, comprising deep love for nature and pro-environmental biospheric values, does significantly influence people's pro-environmental interests, attitudes, and choices, including preferences for nature based leisure experiences. More specifically, love and caring for nature was the most important influence (more than values or beliefs) on pro-environmental choices and behaviours, which were indicative of a stronger environmental ethic. Such behaviours and choices involved more effort and commitment on the part of the individual, including willingness to make personal sacrifices to protect the environment. The new 15-item measure of the construct of love for nature, the Love and Care for Nature (LCN) scale (Perkins, 2010), is easily administered and has potential application across a wide variety of contexts for predicting a pro-environmental orientation and pro-environmental behaviour, as well as interest in nature based leisure experiences.
Leisure, Living, Learning: Education in Sport, Tourism and the Outdoors
Psychology and Cognitive Sciences


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Social context: group
Typical strategies: guided discovery
Outdoor learning extends the classroom into the great outdoors, where a wider range of activities can be undertaken, typically for team-building and leadership development. Most outdoor learning is experiential: participants are allocated to groups and are set tasks, perhaps crossing a lake or building a shelter; when the task has been completed they then review how they went about the task and make new generalisations about the process they should follow in future.
Outdoor learning is:
- at its best when voluntary, open in terms of outcomes, designed to suit all ages and fitness levels, facilitated by skilled trainers;
- best avoided when mandatory, contrived in terms of outcomes, overly demanding physically.


were stressed and dying. The conservatory started pH testing and treating their water with acid, and the remaining palms were saved though many beautiful trees had already died.
(a moment of silence for the palms)
The sad story of the palms goes to show that sources of water can be pretty radically different and have a big effect on plants. Truly pure water essentially doesn't exist. Water is sometimes called the universal solvent because almost anything can, and does, dissolve into it. Even ultra-super-extra-triple distilled water won't stay perfectly pure for long. As soon as it is exposed to air, carbon dioxide will dissolve into it and make it slightly acidic. So don't be fooled by "pure" bottled waters. If it was truly pure, it would cost a lot more (ultrapure, research-grade water costs about $25 a liter), and besides, extremely pure water tastes unpleasant, and isn't good for you.
City water comes from various sources like wells, lakes, rivers and treated sewage (yum...) and picks up all sorts of different minerals, salts, and gasses along the way. Water treatment plants remove some of those compounds, add others, and sterilize it to make it safe for people to drink. The emphasis here is on people, and some water treatments aren't all that good for plants. Some plants are sensitive to chlorine, and water softeners take out excess dissolved minerals in water (which are mostly fine for people or plants) and by replacing them with dissolved salts (which are very bad for plants). Rain water generally has less stuff dissolved in it than tap water, but it isn't pure either, not by a long shot. Clouds contain not just water, but also various dust, gasses, and (unfortunately) industrial air pollution, making rain water chemically different than tap water.
So how might the difference between rain water and tap water be effecting your plants? As demonstrated by the palm story I started with, pH could be a big one. Rain water is slightly acidic (or not so slightly, if you've got acid rain) whereas most tap water is alkaline due to dissolved minerals. It may be that over the summer your soil pH slowly goes up, out of the plant comfort zone, and then gets brought back down with the arrival of the fall rains. You could test this theory pretty easily be measuring your pH before and after the rains start.
Another option would be mineral and salt build up. Most tap water contains a fair amount of dissolved minerals, and fertilizers (of any sort -- organic or synthetic) are salts. As water evaporates from the soil, it leaves the minerals and salts behind, which over time can affect the health of the plants. In extreme cases, like house plant that have been around forever, you might even see a crusty white layer on the surface of the soil. Rain water is purer than most tap water, and coming in large amounts could flush out the excess minerals and salts letting plants grow more happily. You could sort of test this one by comparing your soil's salt concentration before and after the rains with an EC (electical condictivity) meter.
It could also be nitrogen. I didn't realize this until I started researching this answer, but rain water can have significant amounts of nitrogen in it (but, then again, so can tap water, especially in agricultural areas). The papers I've looked at on the subject find the amount to be pretty variable by region and season, so your local fall rains may or may not be giving your plants a fertilizer boost along with hydration.
Finally, as I mentioned above, the water treatment process adds chemicals like chlorine to tap water, which some plants are sensitive to. These may be slowly building up in the soil over the watering season gradually hurting the health of the plant.
In short, rain water is very different from most tap water, and the "inner happiness" your plant exhibit with the arrival of fall rains isn't a figment of your imagination nor a drug-addled hallucination, though it is hard to say for sure which factor or combination of factors are responsible for their joy.


You asked: How often should you get acupuncture for headaches?
A clinical study of acupuncture for cluster headaches recommended treatment twice a week for two weeks, followed by one treatment per week for eight weeks, and maintenance treatments of once every other week after that.
How many sessions of acupuncture do you need for migraines?
Treatment takes about an hour, and patients are advised to undergo at least six sessions, usually once a week. The acupuncturist may also suggest dietary changes.
How often is too often for headaches?
How does acupuncture cure headaches?
The needle stimulates the nerves to release hormones, such as endorphins, that trigger a response from your body. This immune and circulation system stimulation is what proponents of acupuncture claim relieves migraines and tension headaches.
IT IS INTERESTING: Is chemotherapy contraindicated for massage?
How long do the effects of an acupuncture treatment last?
Since acupuncture helps to develop new habits of healing, chronic symptoms and issues are known to take a longer time to reap the full benefits of acupuncture. However, once your body is used to the new nerve pathway that has been built, the benefits of acupuncture are shown to last for months longer.
What gets rid of migraines fast?
In this Article
 1. Try a Cold Pack.
 2. Use a Heating Pad or Hot Compress.
 3. Ease Pressure on Your Scalp or Head.
 4. Dim the Lights.
 5. Try Not to Chew.
 6. Hydrate.
 7. Get Some Caffeine.
 8. Practice Relaxation.
What are the negative side effects of acupuncture?
Is it bad to have headaches everyday?
Most people get headaches once in a while but it's not normal to have a headache every day. Make an appointment with your primary care provider to get checked. In the meantime it's a good idea to keep a diary of your headaches.
Why am I getting frequent headaches?
How many headaches a week is normal?
Experts say that getting more than two headaches a week for longer than a fortnight could signal a serious condition, and it is best to consult a doctor about it. It has come to light that people take the effects of headache very lightly.
IT IS INTERESTING: What are the educational requirements for a doctor of osteopathy?
What pressure point makes you fall asleep instantly?
Spirit gate
The spirit gate point is located at the crease on your outer wrist, below your pinkie finger. To treat insomnia: Feel for the small, hollow space in this area and apply gentle pressure in a circular or up-and-down movement. Continue for two to three minutes.
Is Acupuncture good for tension headaches?
Is acupuncture on the head safe?
Since the skull protects the brain and there are no organs in the scalp to injure it is a very safe treatment. Scalp Acupuncture works by stimulating the brain cells that are related to the impaired functions.
Should you drink water after acupuncture?
How do you know if acupuncture is working?
What should you not do after acupuncture?
IT IS INTERESTING: You asked: Is seeing a chiropractor good for you?


Know The Major Components Of Your UPS Power Supply System
A UPS power supply system is an indispensable part of almost any kind of industry. But you would definitely ask, why should I learn what is inside the UPS?
The answer is, when you know the key components, you can easily understand its working procedure, identify a potential trouble and try to avoid them in the course.


Hippocampal remapping as hidden state inference
TitleHippocampal remapping as hidden state inference
Publication TypeJournal Article
Year of Publication2020
AuthorsSanders, H, Wilson, MA, Gershman, SJ
Date Published06/2020
Cells in the hippocampus tuned to spatial location (place cells) typically change their tuning when an animal changes context, a phenomenon known as remapping. A fundamental challenge to understanding remapping is the fact that what counts as a ‚Äò‚Äòcontext change‚Äô‚Äô has never been precisely defined. Furthermore, different remapping phenomena have been classified on the basis of how much the tuning changes after different types and degrees of context change, but the relationship between these variables is not clear. We address these ambiguities by formalizing remapping in terms of hidden state inference. According to this view, remapping does not directly reflect objective, observable properties of the environment, but rather subjective beliefs about the hidden state of the environment. We show how the hidden state framework can resolve a number of puzzles about the nature of remapping.
Associated Module:
CBMM Relationship:
 - CBMM Funded


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bathotpix - locate and mask out hot pixels in a BAT detector image
bathotpix infile outfile
bathotpix locates hot pixels in a BAT detector plane image. Hot
pixels can be a source of noise in subsequent image processing steps,
and so should usually be excised.
This tool uses a histogram-based approach to locate the hottest and
coldest pixels in the image. Given a distribution of counts, the
"centermost" portion is selected as being good (the "keepfract"
amount). If keepfract is 0.98, then 98% of the detectors are selected
as good. The selection window is further enlarged by bands on either
side using the guardfract and guardval parameters. Values outside the
selection window are considered to be "cold" (too low) or "hot" (too
The output of the tool is a quality map of the same dimensions as the
detector image. Values stored in the map are determined by the
keywords below, but typically a value of 0 indicates a good pixel.
This mask can be input into downstream image processing stages. The
second extension, BADPIX, is a binary table containing a list of bad
Users can submit an existing detector mask using the detmask
parameter. Pixels with bad quality are ignored by bathotpix in
computing the distribution and selection windows. By default, the
input mask is logically AND'd with the result, so that the output is
the cumulative record of excised pixels. By default, BAT detector
gaps are also excised.
- infile [filename]
- Input file name containing a detector plane image.
- outfile [filename]
- Output detector mask image.
- (detmask = "NONE") [string]
- Input detector mask image. Pixels with bad quality are ignored in
the bathotpix analysis.
- (row = 1) [integer]
- Image number to process, where the first image is number 1. This
applies both to files with multiple image extensions (where 'row'
selects the extension number) and to files with one binary table
extension (where 'row' selects the table row).
- (keepfract = 0.98) [real]
- Fraction of non-zero detectors to select as good, initially.
- (guardfract = 0.25) [real]
- Fractional amount to enlarge initially selected detectors,
relative to the median value. A value of 0.25 indicates an
enlargement of 0.25 x the median on both sides of the distribution.
- (guardval = 5.0) [real]
- Further amount to enlarge the selection window, this time in
counts. This keyword is present for the case of an image with very
small dynamic range, where guardfract may be too small to be
- (applygaps = yes) [boolean]
- If yes, then positions of BAT detector gaps are excised.
- (mergemask = yes) [boolean]
- If yes, then the input mask is merged with the result before
writing to the output. If no, then only the pixels adjusted within
this run of bathotpix are written.
- (zerothresh = 20.0) [real]
- Threshold value. If the median is above zerothresh, then pixels
with zero are considered to be COLD. If the median is below
zerothresh, i.e. the total number of counts is very low, then pixels
with zero are considered to be okay.
- (goodval = 0) [integer]
- Value to be used in detector mask maps to indicate a good pixel.
- (badval = 1) [integer]
- Value to be used in detector mask maps to indicate a bad pixel, such
as a detector gap.
- (hotval = 1) [integer]
- Value to be used in detector mask maps to indicate a hot pixel.
- (coldval = 1) [integer]
- Value to be used in detector mask maps to indicate a cold pixel.
- (clobber = NO) [boolean]
- If the output file already exists, then setting "clobber = yes" will cause it to be overwritten.
- (chatter = 1) [integer, 0 - 5]
- Controls the amount of informative text written to standard
output. Setting chatter = 1 produces a basic summary and image
statistics; chatter = 2 (default) additionally prints a summary of
input parameters; chatter = 3 prints detailed information on which hot
and cold detectors; chatter = 5 prints debugging information.
- (history = YES) [boolean]
- If history = YES, then a set of HISTORY keywords will be written to
the header of the specified HDU in the output file to record the value
of all the task parameters that were used to produce the output
1. Locate hot pixels in a detector plane image
bathotpix image.dpi image.mask
2. Same as example 1, but an input mask is also supplied
bathotpix image.dpi image.mask detmask=apriori.mask


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A combination product containing damiana, tryptophan, boron and royal jelly to ensure feminine wellbeing.
Pack of 60 capsules.
Royal jelly is a substance that worker bees secrete as nutrition for all the larvae of the bee colony. The queen bee is fed with royal jelly throughout its life.
Damiana is also considered to be an aphrodisiac. It grows as a bush in South America and in western India, where it has been used for about a thousand years as an aphrodisiac.
Tryptophan is one of the essential amino acids, i.e. it cannot be produced in sufficient amounts by the human body itself. Like all other amino acids, tryptophan is needed to make proteins. Tryptophan formed in the body is used in various compounds, such as the neurotransmitter serotonin, the hormone melatonin, and niacin.
Your email address will not be published. Required fields are marked *


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Imagine that you are a nutritionist trying to explore the nutritional content of food. What is the best way to differentiate food items? By vitamin content? Protein levels? Or perhaps a combination of both?
Knowing the variables that best differentiate your items has several uses:
1. Visualization. Using the right variables to plot items will give more insights.
2. Uncovering Clusters. With good visualizations, hidden categories or clusters could be identified. Among food items for instance, we may identify broad categories like meat and vegetables, as well as sub-categories such as types of vegetables.
The question is, how do we derive the variables that best differentiate items?
Principal Components Analysis (PCA) is a technique that finds underlying variables (known as principal components) that best differentiate your data points. Principal components are dimensions along which your data points are most spread out:
A principal component can be expressed by one or more existing variables. For example, we may use a single variable – vitamin C – to differentiate food items. Because vitamin C is present in vegetables but absent in meat, the resulting plot (below, left) will differentiate vegetables from meat, but meat items will clumped be together.
To spread the meat items out, we can use fat content in addition to vitamin C levels, since fat is present in meat but absent in vegetables. However, fat and vitamin C levels are measured in different units. To combine the two variables, we first have to normalize them, meaning to shift them onto a uniform standard scale, which would allow us to calculate a new variable – vitamin C minus fat. Combining the two variables helps to spread out both vegetable and meat items.
The spread can be further improved by adding fiber, of which vegetable items have varying levels. This new variable – (vitamin C + fiber) minus fat – achieves the best data spread yet.
While in this demonstration we tried to derive principal components by trial-and-error, PCA does this by systematic computation.
Using data from the United States Department of Agriculture, we analyzed the nutritional content of a random sample of food items. Four nutrition variables were analyzed: Vitamin C, Fiber, Fat and Protein. For fair comparison, food items were raw and measured by 100g.
Among food items, the presence of certain nutrients appear correlated. This is illustrated in the barplot below with 4 example items:
Specifically, fat and protein levels seem to move in the same direction with each other, and in the opposite direction from fiber and vitamin C levels. To confirm our hypothesis, we can check for correlations (tutorial: correlation analysis) between the nutrition variables. As expected, there are large positive correlations between fat and protein levels (r = 0.56), as well as between fiber and vitamin C levels (r = 0.57).
Therefore, instead of analyzing all 4 nutrition variables, we can combine highly-correlated variables, leaving just 2 dimensions to consider. This is the same strategy used in PCA – it examines correlations between variables to reduce the number of dimensions in the dataset. This is why PCA is called a dimension reduction technique.
Applying PCA to this food dataset results in the following principal components:
The numbers represent weights used in combining variables to derive principal components. For example, to get the top principal component (PC1) value for a particular food item, we add up the amount of Fiber and Vitamin C it contains, with slightly more emphasis on Fiber, and then from that we subtract the amount of Fat and Protein it contains, with Protein negated to a larger extent.
We observe that the top principal component (PC1) summarizes our findings so far – it has paired fat with protein, and fiber with vitamin C. It also takes into account the inverse relationship between the pairs. Hence, PC1 likely serves to differentiate meat from vegetables. The second principal component (PC2) is a combination of two unrelated nutrition variables – fat and vitamin C. It serves to further differentiate sub-categories within meat (using fat) and vegetables (using vitamin C).
Using the top 2 principal components to plot food items results in the best data spread thus far:
Meat items (blue) have low PC1 values, and are thus concentrated on the left of the plot, on the opposite side from vegetable items (orange). Among meats, seafood items (dark blue) have lower fat content, so they have lower PC2 values and are at the bottom of the plot. Several non-leafy vegetarian items (dark orange), having lower vitamin C content, also have lower PC2 values and appear at the bottom.
Choosing the Number of Components. As principal components are derived from existing variables, the information available to differentiate data points is constrained by the number of variables you start with. Hence, the above PCA on food items only generated 4 principal components, corresponding to the original number of variables in the dataset.
Principal components are also ordered by their effectiveness in differentiating data points, with the first principal component doing so to the largest degree. To keep results simple and generalizable, only the first few principal components are selected for visualization and further analysis. The number of principal components to consider is determined by something called a scree plot:
A scree plot shows the decreasing effectiveness of subsequent principal components in differentiating data points. A rule of thumb is to use the number of principal components corresponding to the location of a kink. In the plot above, the kink is located at the second component. This means that even though having three or more principal components would better differentiate data points, this extra information may not justify the resulting complexity of the solution. As we can see from the scree plot, the top 2 principal components already account for about 70% of data spread. Using fewer principal components to explain the current data sample better ensures that the same components can be generalized to another data sample.
Maximizing Spread. The main assumption of PCA is that dimensions that reveal the largest spread among data points are the most useful. However, this may not be true. A popular counter example is the task of counting pancakes arranged in a stack, with pancake mass representing data points:
To count the number of pancakes, one pancake is differentiated from the next along the vertical axis (i.e. height of the stack). However, if the stack is short, PCA would erroneously identify a horizontal axis (i.e. diameter of the pancakes) as a useful principal component for our task, as it would be the dimension along which there is largest spread.
Interpreting Components. If we are able to interpret the principal components of the pancake stack, with intelligible labels such as "height of stack" or "diameter of pancakes", we might be able to select the correct principal components for analysis. However, this is often not the case. Interpretations of generated components have to be inferred, and sometimes we may struggle to explain the combination of variables in a principal component.
Nonetheless, having prior domain knowledge could help. In our example with food items, prior knowledge of major food categories help us to comprehend why nutrition variables are combined the way they are to form principal components.
Orthogonal Components. One major drawback of PCA is that the principal components it generates must not overlap in space, otherwise known as orthogonal components. This means that the components are always positioned at 90 degrees to each other. However, this assumption is restrictive as informative dimensions may not necessarily be orthogonal to each other:
To resolve this, we can use an alternative technique called Independent Component Analysis (ICA).
ICA allows its components to overlap in space, thus they do not need to be orthogonal. Instead, ICA forbids its components to overlap in the information they contain, aiming to reduce mutual information shared between components. Hence, ICA's components are independent, with each component revealing unique information on the data set.
Information has thus far been represented by the degree of data spread, with dimensions along which data is more spread out being more informative. This is may not always be true, as seen from the pancake example. However, ICA is able to overcome this by taking into account other sources of information apart from data spread.
Therefore, ICA may be a backup technique to use if we suspect that components need to be derived based on information beyond data spread, or that components may not be orthogonal.
PCA is a classic technique to derive underlying variables, reducing the number of dimensions we need to consider in a dataset. In our example above, we were able to visualize the food dataset in a 2-dimensional graph, even though it originally had 4 variables. However, PCA makes several assumptions, such as relying on data spread and orthogonality to derive components. On the other hand, ICA is not subjected to these assumptions. Therefore, when in doubt, one could consider running a ICA to verify and complement results from a PCA.
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Thanks to Aram Dovlatyan for pointing out a typo in this post.
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