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Lara Croft Tomb Raider: The Angel of Darkness
Following a protracted absence from our screens, the original all action heroine makes a long overdue PS2 debut
Release Date: Out Now
Publisher: Eidos
Developer: Core Design
OVERVIEW GAME FEATURES
The world's most celebrated gaming character finally arrives on PS2 for what promises to be her most epic adventure to date. With an altogether darker tone compared previous games in the TR series, a second playable character and all new gameplay elements, Tomb Raider: Angel of Darkness sees the well loved series truly coming of age. While the classic Tomb Raider trappings - huge, expansive environments, tricky timed jumps and fiendish puzzles - are all present and correct, they're supplemented with interaction with non-player characters, RPG-style character development and all new stealth moves. The game's storyline is laced with intrigue and mystery, and sees Lara on the wrong side of law as she trawls across Paris and Prague in search of five 14th Century artworks known as the Obscura Paintings. In the struggle to clear her name and prevent the paintings falling into the wrong hands, Lara uncovers a trail of underworld dealings and grotesque murders, and a history of blood, betrayal and vengeance that spans hundreds of years...
Lara's latest epic adventure begins in Paris, where she meets her former mentor Werner Von Croy, who has been tasked by a mysterious client named Eckhardt to track down five 14th century Obscura paintings. Following a furious argument between the two, Lara discovers her mentor murdered and, as the prime suspect, flees the scene. On the run from the police, Lara follows Eckhardt's trail from the back streets of Paris to Prague, where a dastardly plan to resurrect the mysterious Nephilim race is underway. Lara must track down the paintings and prevent Eckhardt and a cultish group of individuals known as the Cabal from unleashing ancient alchemic powers on the world. On her travels, Lara encounters a fellow adventurer, Kurtis Trent, who's also hot on Eckhardt's trail.
This latest adventure for gaming's first lady is stunningly realised, with hugely detailed envirnoments and spectacular lighting and weather effects. Lara is easier on the eye than ever; she's now comprised of 5,000 polygons (compared to just 500 in previous TS games), and has over 250 animations at her disposal, which is just as well, really, given her astonishing range of abilities. As well as her existing range of moves (climbing, monkey-swinging and somersaulting, to name but a few), Lara can now engage enemies in hand-to-hand combat, perform stealth manouevres and more besides.
For many hardened PlayStation adventurers, the words 'Tomb Raider' are reason enough to check out this latest offering from Core Design. For those less familiar with Lara's running, shooting and jumping antics, Angel of Darkness is the perfect opportunity to see what all the fuss is about.
All new gameplay elements; build up Lara's upper body strength and jumping abilities by solving puzzles and exploring
New moves and abilities include hand-to-hand combat and stealth manoeuvres
Play as Kurtis Trent, a new character with his own distinctive moves and gameplay mechanics, including the terrifying Chirugai blade
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text: Q: Gnome Disk Utility - "SMART Data & Self Tests..." Option greyed out The option for "SMART Data & Self Tests..." is not available (greyed out) in Gnome Disk Utility on 22.04. I have smartmontools installed and can read information about the disk, including test results and errors by running smartctl commands. I'm hoping to get this working in Gnome because I'd like to get notifications if errors start showing up.

redpajama_set_name: RedPajamaStackExchange


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Is This Baboon Skull a Clue to Egypt's Lost Kingdom of Punt
Photo Courtesy The Trustees of the British Museum
New evidence based on a mummified baboon skull may help unlock the secrets of a lost civilization.
Candida Moss
Updated Jan. 04, 2021 3:51PM ET / Published Jan. 04, 2021 5:03AM ET
When we think of the ancient world, we usually think of Egypt, Greece, Rome, Persia, India, and China. But when the ancient Egyptians thought of mysterious and wealthy kingdoms they spoke of "God's Land" or the Land of Punt. Expeditions to this kingdom—which was rich in gold, ebony, ivory, and frankincense—were memorialized by the Egyptians on the walls of temples and alluded to in ancient folklore. But despite the fact that the Land of Punt was a real place and a major trading partner of Egypt's, its precise location had been lost. Now new evidence, based on a mummified baboon skull, may help unlock the secrets of this lost civilization.
The Red Sea and ancient Egypt were part of a trade network that drove maritime technology for thousands of years. Punt also formed part of this ancient spice route and was well known for exporting luxury goods, in particular high-quality incense and prized sacred monkeys. Ancient sources suggest that travelers could reach Punt by journeying south and east of Egypt, leading some to identify the kingdom with Ethiopia or the horn of Africa, but the exact location of this country is a mystery.
One clue to unlocking this mystery is the prevalence of the sacred baboon (Papio hamadryas) in ancient Egyptian art and religion. Baboons can be found on statues, jewelry, amulets, and in temple artwork. Some baboons may have been pets, others are shown in art working as police animals and fruit harvesters, and many are associated with royal tombs. They even achieved quasi-divine status, being particularly associated with the baboon-headed god Thoth (who is also regularly depicted with an Ibis head), who was associated with the moon and wisdom. The image of the male baboon seated with hands on knees and surrounded by a lunar crescent is an archetypal image that was used in Egyptian artwork for a millennium. Figures of the seated baboon spread throughout the Mediterranean in the Middle Bronze Age, but the further you travel away from Egypt the less realistic the image of the baboon gets.
In the bowels of the British Museum, primatologist Professor Nathaniel Dominy of Dartmouth College discovered the remains of two hamadryas baboons. The baboons were mummified in the same seated pose that was so popular in ancient artwork and one has since been dismantled. The remains had been discovered at the Temple of Khons in ancient Thebes and were donated to the museum by the estate of Henry Salt, the British consul-general in Egypt between 1816 and 1827. Salt was one of a cluster of ethically questionable European diplomats-turned-amateur antiquities collectors who competed with one another to acquire as many antiquities as they could. Salt's mummified baboons, however, are a curious discovery because baboons are not native to Egypt. There are no monkey species among the fossil records and ecological modeling suggests that baboon distribution has remained unchanged over the past 20,000 years. Where did these baboons come from? Dominy and his colleagues wanted to find out.
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In an effort to identify their baboon's birthplace, Dominy and his collaborators analyzed the chemical isotopes in the tooth enamel of one of the baboon skulls. The ratio of strontium isotopes in soil and water varies from region to region and is locked into a primate's tooth enamel when they are young. By identifying the baboon tooth's isotopic signature, the team hoped to pinpoint the place where the baboon had been born.
The results of the analysis confirmed what the team had suspected: the baboon had been brought to Egypt from somewhere else. Further comparative analysis of the remains of other baboons found in ancient Egyptian tombs revealed that while some were raised in captivity in Egypt, others had been born outside of the region. A large comparative study of over 150 baboons from 77 locations in East Africa and the Arabian Peninsula suggests that the British Museum baboon was born in a region that overlaps with modern-day Ethiopia, Eritrea, Djibouti, and parts of Somalia and Yemen. Given that many archeologists believe that Punt was roughly equivalent with this region, Dominy et al. argue that the baboon skull is the earliest known Puntite treasure. The discovery is a significant contribution that helps cement the theory that the wealthy Land of the Gods was located in the same area as Ethiopia and Eritreia.
Not every archaeologist agrees that these mummies are the earliest Puntite artifacts, however. Kathryn Bard, an archaeologist at Boston University who excavated a site on Egypt's Red Sea coastline, told Science that ebony and obsidian fragments she discovered at Wadi Gawasis are older. During her excavations there she also uncovered Sudanese/Ethiopic style pottery fragments. For his part Dominy says that while the ebony artifacts from Wadi Gawasis are important, the widespread distribution of ebony throughout Africa means that they cannot be definitively identified as originating in Punt.
Regardless of which ancient remnant is the oldest, Dominy's findings are significant. They help demonstrate the influence that ancient Ethiopia and Eritrea had on the cultural and religious thought of Egypt and, through Egypt, on the rest of the ancient Mediterranean. This recognition is important because Ethiopia and Eritrea rarely figure in popular histories of the ancient world. Instead, popular imagination focuses on ancient empires that have been traditionally—and, often, inaccurately—conceived of as white. Moreover, this research proves quite definitely that the baboon god is the lone non-native interloper in the pantheon of Egyptian deities. The baboon's ascent from luxury import good, to immigrant worker, sacred guard dog, royal pet and, finally, deity is one of history's great success stories.

redpajama_set_name: RedPajamaCommonCrawl


On the evening of April 15—the day two bombs exploded at the Boston Marathon, killing three people and wounding more than two hundred eighty—President Barack Obama vowed that those responsible "will feel the full weight of justice." In light of the country's history of injustice in dealing with suspected terrorists since 9/11, Obama's vow was less a threat than a promise.
In recent months, an increasing number of desperate prisoners have engaged in hunger strikes to call attention to their plight. At the end of April, one hundred detainees were considered by the military to be on hunger strike. Those who have persisted longest are being force-fed—itself a form of abuse, according to the World Medical Association—to prevent them from starving to death. Reporter Carol Rosenberg found that at least four of those being force-fed are among those cleared for release.
At his 2009 inauguration, Obama pledged to close Guantánamo within a year, saying, "We reject as false the choice between our safety and our ideals." But Congress blocked attempts to move detainees to the mainland, transfer others, and try accused terrorists in civil courts. Obama's defense department could still authorize the transfer of the cleared detainees by issuing individual waivers. The president could also do much more to pressure foreign governments to accept those cleared of terrorist charges. But he seems to prefer the scandal of indefinite detention to pursuing the politically awkward remedies that justice and common human decency demand.
The detainees at Guantánamo are starving themselves to death because they have given up on American promises of justice. Their situation is a continuing scandal for the United States, and a reminder of the grave errors made after 9/11. The difficulty of restoring them to justice is reason enough to avoid making the same mistakes again in response to new acts of terror.


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In our earlier article, we have covered about phpPgAdmin configuration on Centos7. In this article, I am going to show how to install the latest PostgreSQL 10 database on Linux and BSD distributions.
Aix download and Install Is there is some free download for this os available to be installed on a home desktop pc with 4 gb ram and 2.7 ibm single proc computer . can some one help me with the download link and installation instructions.
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Articles, Cellular/Molecular
Mechanoelectric Transduction of Adult Inner Hair Cells
Shuping Jia, Peter Dallos and David Z. Z. He
Journal of Neuroscience 31 January 2007, 27 (5) 1006-1014; DOI: https://doi.org/10.1523/JNEUROSCI.5452-06.2007
Shuping Jia
Peter Dallos
David Z. Z. He
Inner hair cells (IHCs) are the true sensory receptors in the cochlea; they transmit auditory information to the brain. IHCs respond to basilar membrane (BM) vibration by producing a transducer current through mechanotransducer (MET) channels located at the tip of their stereocilia when these are deflected. The IHC MET current has not been measured from adult animals. We simultaneously recorded IHC transducer currents and BM motion in a gerbil hemicochlea to examine relationships between these two variables and their variation along the cochlear length. Results show that although maximum transducer currents of IHCs are uniform along the cochlea, their operating range is graded and is narrower in the base. The MET current displays adaptation, which along with response magnitude depends on extracellular calcium concentration. The rate of adaptation is invariant along the cochlear length. We introduce a new method of measuring adaptation using sinusoidal stimuli. There is a phase lead of IHC transducer currents relative to sinusoidal BM displacement, reflecting viscoelastic coupling of their cilia and their adaptation process.
mechanotransduction
inner hair cells
cochlear mechanics
The organ of Corti in the mammalian cochlea, situated between the basilar membrane (BM) and the tectorial membrane (TM), is a matrix of sensory and supporting cells. The organ transforms transversal BM vibration into a radial shear stimulus at the apices of the sensory hair cells (ter Kuile, 1900; Hu et al., 1999). There are two types of sensory receptor cells in the mammalian organ of Corti: the inner hair cells (IHCs) and the outer hair cells (OHCs). Both types of hair cell have elongated actin-based villi named stereocilia emerging from their apical surface. The deflection of the ciliary bundle during BM vibration and the subsequent flow of transducer current through the mechanotransducer (MET) channels at the tips of the stereocilia (Hudspeth, 1982; Denk et al., 1995; Lumpkin and Hudspeth, 1995) produce the receptor potential in both IHCs and OHCs (Russell and Sellick, 1978; Dallos et al., 1982; Dallos, 1985). The receptor potential generated by IHCs facilitates the release of neurotransmitters at their synaptic end (for review, see Sewell, 1996). The receptor potential produced by OHCs, however, provides the stimulus to their motor activity (Brownell et al., 1985; Kachar et al., 1986; Ashmore, 1987), which is believed to power the cochlear amplifier (Dallos, 1992).
Although IHC receptor potentials have been recorded with sharp electrodes from adult animals in vivo (Russell and Sellick, 1978; Dallos, 1985) and culture preparations of neonatal mice (Russell et al., 1986a,b), the MET current has not been measured from the IHCs of adult animals. Therefore, knowledge of the basic properties of IHC transducer currents, quantitative relationships between them and BM displacements, as well as their variation along the cochlear length are still lacking. We simultaneously recorded IHC transducer currents and BM motion in an excised and bisected cochlea, the hemicochlea (Richter et al., 1998; Hu et al., 1999), in the same way that OHC transducer currents were measured previously (He et al., 2004). This preparation permits recordings from adult hair cells in situ at various cochlear locations while the BM is mechanically stimulated. A preliminary report on this work was presented previously (Jia et al., 2005).
Preparation of the hemicochlea.
Details of preparing the gerbil (Meriones unguiculatus) hemicochlea and its quality control were described previously (Richter et al., 1998; Hu et al., 1999). In brief, gerbils ranging in age from 25 to 35 d after birth were used for the experiments. After intraperitoneal injection of a lethal dose of sodium pentobarbital (150 mg/kg), the cochleae were dissected out and placed in artificial perilymph [Leibovitz's (L-15) medium; Invitrogen, San Diego, CA]. The cochlea was glued onto the surface of a small metal block. The block was immersed in the cutting bath of a standard Vibratome (series 1000; TPI, St. Louis, MO) filled with L-15 medium after the glue had hardened (∼5 min). The cochlea was aligned with the cutting edge of the blade until all cochlear-turn boundaries were perpendicular to the blade. After speed and amplitude were selected for cutting, the vibrating blade cut the cochlea into two parts from apex to base along the modiolar axis. Either of the resulting hemicochleae can be used for the experiments. Hair cells started to become swollen in <25 min after the cochlear wall was open and the organ of Corti was exposed to the L-15 medium. Therefore, all of the data presented were collected within 20 min. Experiments were done at room temperature (22 ± 2°C).
Whole-cell voltage clamp.
The hemicochlea was bathed in L-15 medium in an experimental chamber mounted on the stage of an upright microscope (DMLFSA; Leica, Nussloch, Germany) with a Burleigh Instruments (Fishers, NY) platform. The L-15 medium contained the following (in mm): 136 NaCl, 5.8 NaH2PO4, 5.4 KCl, 1.4 CaCl2, 0.9 MgCl2, 0.4 MgSO4, 10 HEPES-NaOH, at pH 7.4 and 300 mOsm L−1. In many experiments, the L-15 medium with 1.4 mm calcium was used as extracellular solution. When the input–output function of the IHC transducer current was determined, the hemicochlea was prepared and bathed in L-15 medium with 50 μm calcium in the extracellular solution. This solution was prepared separately and contained the following (in mm): 136 NaCl, 5.8 NaH2PO4, 5.4 KCl, 0.05 CaCl2, 2 Na-pyruvate, 10 glucose, and 10 HEPES-NaOH, at pH 7.4 and 300 mOsm L−1. To determine the effect of calcium on adaptation, low calcium (50 μm) perilymph was perfused to the bath solution by a perfusion pump after transducer currents were first measured at a 1.4 mm calcium concentration. The pipette solution contained the following (in mm): 140 CsCl, 0.1 CaCl2, 3.5 MgCl2, 2.5 MgATP, 5 EGTA-KOH, 5 HEPES-KOH, at pH 7.4 and 300 mOsm L−1. Pipette resistances were 3–4 MΩ. Recordings were made in whole-cell voltage-clamp mode, using an Axopatch 200B patch-clamp amplifier (Molecular Devices, Palo Alto, CA). Series resistance was 8–12 MΩ, and ∼75% of the series resistance was compensated. Currents were filtered at either 2 or 5 kHz and digitized at 10 or 20 kHz with a 16-bit A/D converter (Digidata 1322A) and pClamp 9.2 software (Molecular Devices). The cells were held at −70 mV.
Mechanical stimulation.
To evoke MET current from IHCs in the hemicochlea, BM displacement was produced by a vibrating paddle. A thin glass fiber was used as a paddle. The glass paddle was pulled from a 1.5 mm outer diameter glass tubing to a tip diameter of 20 μm. The tip was then heat polished and fused to a 60 μm spherule. The paddle was mounted on a piezoelectric actuator (Driver/Amplifier, PZ-150M; Burleigh Instruments), which was mounted on another three-dimensional Narashige micromanipulator (MHW-3). The paddle was positioned below the middle point of the pectinate zone of the BM. Upward motion of the paddle would result in the BM moving toward the scala vestibuli. To determine the relationship between the BM motion and MET current, 500 or 100 Hz sinusoidal voltage bursts with different amplitudes were used. Paddle vibration was coupled through the fluid to the BM, because the paddle was not in direct contact with the BM. To measure adaptation of the MET currents, the paddle was loaded onto the top surface of the TM underneath Reissner's membrane. Fiber-driven downward motion of the TM presumably engaged the stereociliary bundle with the underside of the TM, making it possible to deflect it with a constant displacement. To reduce transients at onset and offset of the step, the DC voltage step was low-pass filtered at either 2.1 or 4 kHz before being fed to the piezoelectric actuator. Because the frequency response of the paddle motion affects the ability to measure fast adaptation, we measured the rise time of paddle motion in response to DC voltage steps by the photodiode displacement measurement system after the paddle was loaded onto the TM. The rise time (between 10 and 90% of the steady-state value) was 0.165 or 0.085 ms, corresponding to a cutoff frequency of ∼2.1 or 4 kHz.
Measurements of BM displacement.
The preparation was obliquely illuminated by a 100 W lamp. The BM was imaged using a 40× water-immersion objective and magnified by an additional 20× relay lens. The magnified image of the edge of the BM was projected onto the photodiode (Hammamatsu, Shizuoka, Japan) through a slit. During measurements, the magnified image of the edge of the BM was positioned near the edge of the slit. The output signal from the photodiode amplifier represented the BM displacement. The photodiode system had a cutoff (3 dB) frequency of 1100 Hz at the highest gain of the amplifier and 4300 Hz at the reduced gain. The signal was then amplified by a 60 dB fixed-gain DC-coupled amplifier. The amplified signal was then low-pass filtered (at 1.1, 2.1, and 4.1 kHz at 60 dB/octave) before being delivered to one of the A/D inputs of a Digidata (1322A; Molecular Devices) signal processor. Calibration of motion was obtained by moving the slit a known amount (0.5 μm) using a piezo driver attached to it (Jia and He, 2005).
Input–output functions of IHC transducer currents
The BM displacement shows shallow and broad tonotopic tuning in the hemicochlea (Richter et al., 1998), probably reflecting the local resonance properties of the cochlear partition. The approximate recording locations were 2.7–3.2 and 8.6–8.9 mm from the base of the cochlea, representing 18–13 and 1–0.6 kHz of the best frequencies in vivo (Müller, 1996). The corresponding best frequencies in the passive hemicochlea are between 0.5 and 1 octave lower (C. P. Richter and P. Dallos, personal communication). Sinusoidal signals at 500 Hz were used to evoke BM vibration. This stimulating frequency is close to the characteristic frequency for the recording location in the apex but is well below the characteristic frequency of the measured location in the base. This frequency is, however, high enough to minimize the effect of adaptation on the magnitude of the transducer currents even at an extracellular calcium concentration of 1.4 mm (see Results). Furthermore, unless otherwise noted, the hemicochleae were bathed in L-15 medium containing 50 μm calcium, a concentration that is close to the calcium concentration of endolymph in vivo (Bosher and Warren, 1978). Lowering the calcium concentration has been demonstrated to significantly slow the rate of adaptation in both mammalian and nonmammalian hair cells (Ricci et al., 2000, 2005; Kennedy et al., 2003).
Transducer currents were recorded using the tight-seal whole-cell voltage-clamp technique from IHCs in hemicochleae that showed no obvious signs of damage or deterioration under the light microscope. Recordings were all made from IHCs two to three layers down from the cutting edge. The criteria for a "good hemicochlea" were described previously (Richter et al., 1998; He et al., 2004). We measured from >90 cells from healthy-looking preparations. The magnitude of the maximal current response varied significantly. We assumed that small responses signified damage to the MET apparatus during preparation. Therefore, we only included data from IHCs with the largest responses for analysis and comparison. Figure 1, A and B, shows an example of simultaneous recordings of the MET current and BM displacement from one IHC each from the apical and basal locations. The BM displacement was essentially symmetrical and linear in magnitude within the range of stimulation. The transducer current at a holding potential of −70 mV was, however, highly asymmetric; BM motion toward scala vestibuli (plotted upward) produced a large increase in inward current, whereas BM displacement toward scala tympani yielded a small decrease in inward current. Similar asymmetry of the transducer current was observed in all cells with large current responses. The upward motion of BM toward scala vestibuli and the subsequent excitation of hair cells are consistent with the general assumption that BM movement toward scala vestibuli rotates the hair bundle in the direction of the tallest stereocilia and thus open transducer channels (Flock, 1965; Hudspeth and Corey, 1977; Kros et al., 1992).
Simultaneous recordings of IHC transducer currents and BM displacement from adult gerbil hemicochleae. Tight-seal recordings are made from two IHCs in the apical and basal turns at a holding potential of −70 mV. Basolateral potassium conductances are blocked by 140 mm CsCl in the patch electrodes. The stimulus frequency is 500 Hz. A, B, An Apical-turn IHC (A) and basal-turn IHC (B) are shown. Upward-plotted displacement represents the BM moving toward the scala media, which evokes an increase in inward current (plotted downward). The calibration bars apply to both apical- and basal-turn IHCs. C, Steady-state transducer current, slope (sensitivity), and conductance plotted as a function of BM displacement for 10 cells (5 cells from each turn). The magnitude of base-to-peak current is plotted against corresponding magnitude of base-to-peak BM displacement. An increase in inward current is plotted upward. For the sake of simplicity, the transducer current (itr) is fitted with first-order Boltzmann functions (solid lines with open and filled circles), and the slope of the current-fit functions (dashed lines) are plotted for the two cells shown in A and B. Curve fitting was accomplished by using IGORPro (WaveMetrics, Lake Oswego, OR), as follows: where x is BM displacement and imax, x1, and α are constants. Curve-fit parameters for the plots shown are for the basal cell and are as follows: imax = 2031.9 pA, x1 = 35.3 nm, α = 16.1 nm. For the apical cell, the curve-fit parameters are as follows: imax = 2195.2 pA, x1 = 82.1 nm, α = 34.4 nm. Slope functions are obtained by differentiating the Boltzmann curves. Open and filled symbols represent the apical- and basal-turn IHCs, respectively.
In Figure 1C, magnitudes of transducer currents, slopes of the current plots, and estimated conductances are presented as a function of BM displacement for the two examples shown in Figure 1, A and B. Current data are fit with first-order Boltzmann functions (see figure legend) for the example shown in Figure 1, A and B. The derivatives (slope functions) of the Boltzmann fits are also shown (dotted lines). To determine whether the magnitude of IHC transducer currents varies along the longitudinal axis of the cochlea, as it does for OHCs (He et al., 2004), we measured IHC transducer currents from 23 cells. Data from 10 cells (5 cells from each location) with the largest responses are included in Figure 1C. These data show that IHC currents saturate at 2088 ± 148.9 and 2025 ± 177.9 pA (mean ± SD) for the apical- and basal-turn IHCs, respectively. Student's t test indicates that the means are not significantly different (p = 0.13). Maximal MET conductance is 29.8 ± 0.26 and 28.9 ± 0.65 nS for the apical- and basal-turn IHCs, respectively. The present numbers from adult IHCs are considerably in excess of those obtained from immature mouse IHCs measured in high calcium (1.4 mm) perilymph in vitro of 4.2 nS (Kros et al., 1992). Although maximum MET currents are very similar, the slopes of the functions differ between apical and basal IHCs. The mean maximal slopes for the basal and apical IHCs are 28.6 ± 3.6 and 15.1 ± 1.1 pA/nm, respectively. The difference, which is significant at the 1% level, simply reflects their different operating ranges: transducer currents of apical cells saturate at ∼200 nm BM displacement and those of basal cells saturate at approximately one-half of that. As a consequence, the slopes also differ by approximately a factor of 2. The operating ranges of IHCs are similar to those of OHCs at a given cochlear location (He et al., 2004). We also measured MET currents from another 12 IHCs (six from each location) in perilymph with 1.4 mm calcium using 100 Hz sinusoidal signals. These measurements showed that the current saturated at 1244.5 ± 45.2 and 1234.9 ± 70.4 pA for the apical- and basal-turn IHCs, respectively. Student's t test shows that the means are not significantly different (p = 0.78). This again demonstrates that magnitude of IHC transducer currents is uniform along the length of the cochlea. The mean maximal slopes for the basal and apical IHCs are 26.5 ± 4.9 pA/nm (n = 6) and 14.7 ± 3.4 pA/nm (n = 6), respectively. Again, the mean maximal slopes differ by approximately a factor of 2.
IHC transducer currents were asymmetrical in response to symmetrical BM displacement (Fig. 1A,B). There was considerable resting current when the preparation was bathed in L-15 medium with 50 μm calcium; ∼13.7 and 12.9% of the transducer channels were open for those apical and basal cells illustrated in Fig. 1, A and B. In L-15 medium with 1.4 mm calcium, the response was more asymmetrical, with ∼2.2 and 2.6% of the transducer channels open at rest for apical and basal cells (data not shown). The asymmetry seen at low calcium concentration appears to approach that in receptor potentials recorded from IHCs in vivo (Russell and Sellick, 1978; Dallos, 1985, 1986; Cheatham and Dallos, 1993). However, the MET currents measured from neonatal IHCs (Kros et al., 1992) and in adult OHCs (He et al., 2004) are more asymmetrical. The explanation is sought from the differences in calcium levels. As we show above (Crawford et al., 1991; Ricci et al., 2005), resting open probability of the MET channels is greater in low external Ca2+ (Ricci et al., 1998).
IHC receptor potentials recorded in vivo using sharp electrodes show a phase lead relative to BM displacement (Nuttall et al., 1981; Russell and Sellick, 1983; Dallos, 1985). We examined the phase relationship between the transducer current and BM displacement. To best study response phases, measurements were made at the 100 Hz stimulus frequency. Phase was determined from the time difference between response and BM displacement peaks. Figure 2 shows an example of such recording from an apical-turn IHC. To reveal the phase relationship between the transducer current and BM displacement, both of these variables are plotted on an expanded time scale for low and high stimulus level signals in Figure 2. It is apparent that the MET current phase leads to BM displacement. The phase lead persisted at all stimulus levels. Among the cells measured, the phase lead was always seen at 100 Hz, but its magnitude was variable between 0.1 and 0.25 cycles at low input levels. The average phase lead at the lowest stimulus level was 0.15 cycle, or 54° (±0.036 cycles SD; n = 11). We measured the phase relationship from six apical- and six basal-turn IHCs at 100 Hz with 1.4 mm calcium. The basal and apical cells did not show different behavior. IHC receptor potentials recorded in vivo using sharp electrodes also show a phase lead approaching 0.25 cycle (90°) relative to BM displacement (Nuttall et al., 1981; Russell and Sellick, 1983; Dallos, 1985). These results are consistent with the notion that the IHC hair-bundle displacement is related to BM velocity at low frequencies (Dallos et al., 1972). The variability and occasional level dependence of the phase lead probably reflect subtly different apposition from experiment to experiment between ciliary bundle and the TM (Freeman and Weiss, 1990; Fridberger et al., 2004). In vivo data obtained with sharp electrodes also reveal significant variability of the IHC phase lead (Cheatham and Dallos, 1999). As we show below, the operation of the adaptation machinery may also contribute to the recorded phase.
A, Transducer current and BM motion measured using 100 Hz sinusoidal stimulation to reveal phase relationship between BM motion and transducer current. BM motion (dotted lines) and transducer current (solid lines) are plotted on an expanded time scale for the lowest and highest stimulation levels applied. Upward-plotted displacement represents the BM moving toward the scala media. This preparation was bathed in perilymph with 1.4 mm calcium. The recording was made from an apical-turn IHC. Note that the current responses show a phase lead relative to the BM displacements. B, A video image of an IHC hair bundle and the TM from a gerbil hemicochlea in the basal turn is shown. The bundle is closely apposed to the Hensen's stripe on the underside of the TM but not in direct contact with it. Scale bar, 10 μm.
Adaptation of the MET currents
For a sustained deflection of the hair bundle, the response in most types of hair cell adapts; the transduction current decays with time constants from tens of microseconds to tens of milliseconds (Eatock et al., 1987; Ohmori, 1987; Assad et al., 1989; Crawford et al., 1989; Holt et al., 1997; Ricci et al., 2000; Kennedy et al., 2003). The adaptation may be a means of ensuring that the sensitivity of the transducer is always maximized at the resting position of the bundle (Eatock, 2000; Holt and Corey, 2000). To determine whether IHC transducer currents also display adaptation and whether the adaptation rate is cochlear location dependent, as it is in nonmammalian hair cells and OHCs (Ricci et al., 2005), we measured this current in response to a sustained deflection of the hair bundles from apical- and basal-turn IHCs. To accomplish this, a different stimulation approach was required. To provide a steady displacement of the cilia within the hemicochlea environment, firm coupling between them and the TM needed to be established. To this end, the driving fiber was loaded onto the upper side of the TM. Under this condition, the IHC hair bundle was deflected by direct contact with the TM during the downward motion of the latter. This presumably engaged the stereociliary bundle with the underside of the TM, probably with Hensen's stripe (Fig. 2B), making it possible to deflect it with a constant displacement. To assess the frequency-dependent properties of the adaptation process, the magnitude of the MET currents was obtained when the TM motion was driven by the paddle (in contact mode). A series of sinusoidal bursts from 20 to 2000 Hz was used to drive the paddle. MET currents were monitored to examine the frequency response obtained with such an approach. The cells were held at −70 mV, and the hemicochlea was bathed in perilymph with 1.4 mm calcium content (to maximize adaptation). Figure 3 shows an example of such recordings. As Figure 3A demonstrates, the magnitude of the MET current increases as the vibration frequency of the paddle increases. The current magnitude reaches a plateau around 500 Hz. The magnitude plots (Fig. 3B) clearly reflect a high-pass character, but with both low- and high-frequency slopes approaching zero. The figure shows fitting the normalized magnitude data with a pole-zero pair having respective corner frequencies at 455 and 25 Hz. It is also apparent that at the intermediate frequencies there is a phase lead with respect to the driving stimulus. The maximal phase lead varies between 23 and 63° in four cells that were included in the analysis (these cells had the largest transducer currents). Using the appropriate phase function computed to correspond to the magnitude of fit (i.e., its Hilbert pair), good agreement with the phase data is obtained. We emphasize that curve fitting was done for the magnitude of data, whereas the good fit of the phase data occurred automatically with the theoretically derived phase function. The data presented are the first frequency-domain description of hair cell MET channel adaptation. The plateau seen in the MET current response, between 500 and 2000 Hz, indicates that our approach of deflecting the IHC bundle by fiber-driven downward motion of the TM is appropriate for examining adaptation with minimal influence of viscoelastic properties of the TM. It also indicates that the use of a sinusoidal stimulus at 500 Hz (Fig. 1) is adequate to describe the properties of the IHC MET channel without significant influence by the adaptation process. To extend these observations, we measured three additional basal- and three apical-turn IHCs with stimulating frequencies up to 4 kHz. Two examples from such recordings are presented in Figure 3D. It is apparent that the plateau in the MET current response is maintained at 4 kHz in both apical- and basal-turn IHCs. The undiminished MET current responses at 4 kHz suggest that the interposed TM itself does not significantly modify (i.e., slow down) the force delivered to the cilia.
A, Transducer current responses (top trace) and TM-loaded fiber motion (bottom trace) measured at different frequencies for an apical-turn IHC, obtained with 1.4 mm calcium in the bath. The driving fiber made contact with the top of the TM, and its displacement was kept constant from frequency to frequency (20, 50, 100, 200, 500, 1000, and 2000 Hz) by adjusting the magnitude of individual voltage bursts to the driver to compensate for small peaks and dips of the response because of the mechanical properties of the vibrating fiber. The recording location was ∼8.6–8.9 mm from the base of the cochlea, representing ∼1–0.6 kHz of the best frequencies in vivo. B, The magnitude (peak to peak) and phase of the current relative to the TM displacement as a function of frequency (data points) is shown. The magnitude plot is normalized to the 2000 Hz response. Magnitude data points are fitted with the real part of the following function: where ω = 2πf and i = (−1)1/2. The fitting constants are as follows: R1 = 1.75 × 107, R2 = 106, K = 3.7 × 10−10 or A = 0.054, τ1 = 6.5 ms, τ2 = 0.35 ms. The imaginary part of the above equation provides the fit to the phase data in the bottom panel without any parameter adjustment. Note that as set up, the high-frequency magnitude asymptote is 1 and the low-frequency asymptote is A = R2/(R1 + R2), which in this case is 0.054. Both low- and high-frequency phase asymptotes are 0. The fitting equation represents a combination high-pass and low-pass filter (or lead–lag network), with a high-pass cutoff frequency at 1/2πτ1 (24.6 Hz) and a low-pass cutoff frequency at 1/2πτ2 (454.7 Hz). deg., Degree. C, Adaptation data obtained from an apical IHC. Black thin lines are single-exponential fits to the decaying part of the plots. Filled circles and the heavy black line are obtained by inverse Laplace transform of the frequency response plot shown in B, with step input and scaling with a Boltzmann fit as shown in Figure 1. D, Transducer current responses and TM-loaded fiber motion measured at different frequencies (20, 50, 100, 200, 500, 1000, 2000, and 4000 Hz) for apical (top) and basal (bottom) IHCs. All of the measurements were performed with 1.4 mm calcium in the bath.
In our next set of experiments, step stimuli with a duration of 20 ms were used to drive the fiber. This is the conventional way of assessing adaptation with steady deflection of the stereocilia. Transducer currents were recorded at the holding potential of −70 mV in the whole-cell voltage-clamp mode. Figure 4A shows an example of such recordings. The transducer current responded to the step stimuli with rapid onset followed by decay. Similar to that seen in mammalian hair cells (Holt et al., 1997; Kennedy et al., 2003; Ricci et al., 2005) and nonmammalian hair cells (Eatock et al., 1987; Ohmori, 1987; Assad et al., 1989; Crawford et al., 1989; Ricci et al., 2000, 2005), the decay of the current responses occurs on two time scales. For the two examples shown in Figure 4, the dominant shorter time constants vary between 0.42 and 1.66 ms (apical) and between 0.41 and 1.55 ms (basal) from smaller to larger current. We measured the adaptation rate from 15 additional cells (a total of 8 cells from the apex and 7 cells from the base) at the lowest stimulus level. These cells had the largest transducer currents, indicating that their MET channels suffered the least damage. The shortest time constants are 0.55 ± 0.12 ms (n = 8) and 0.58 ± 0.14 ms (n = 7) for the apical- and basal-turn IHCs, respectively. Student's t test shows that there is no statistically significant difference between them (p = 0.62). Although it is usual to fit adaptation with two exponential functions, for most of our IHCs, curve fitting with a single exponential would have been adequate. For example, for the heavy black curve in Figure 3C, the ratio of magnitudes of the two fitting exponentials is 6.5. Thus, the shorter time constant accounts for much of the response behavior.
A, Adaptation of the transducer current obtained from apical- and basal-turn IHCs. Glass fiber was loaded onto the top of the TM, and step stimuli with durations of 20 ms were applied. The motion of the fiber (measured by the photodiode technique) is plotted in the top panels. Downward deflections of fiber motions resulted in the downward motion of the TM and thereby deflected the hair bundle in the excitatory direction. The photodiode signal was low-pass filtered at 2.5 kHz. As shown in the inset, the rise time of the step displacement is ∼0.165 ms, corresponding to a cutoff frequency of ∼2.1 kHz. The IHCs were voltage clamped at −70 mV. The current displays rapid activation and adaptation. The adaptation time constants increase from small to large current. Time constants were calculated using a double-exponential fit (red lines). The shorter time constants are 0.41, 0.93, 1.18, and 1.65 ms (apical-turn IHC) and 0.42, 0.83, 1.0, and 1.52 ms (basal-turn IHC), from small to large currents. The time constants significantly increased (response decay slowed down) after the calcium concentration in the bath medium was reduced to ∼50 μm. In the insets, MET currents at the lowest stimulation levels are plotted on expanded time scales to demonstrate the change in magnitude and adaptation of the MET current between the calcium concentrations of 1.4 mm and 50 μm. B, Effect of onset speed (rise time) on the fast time constant of adaptation. The recording was made from a basal-turn IHC. The driving voltage step to the piezoelectric actuator was low-pass filtered with an eight-pole Bessel filter set at either 2.1 or 4 kHz. MET current and TM-loaded fiber motion were measured and plotted on the expanded time scale. The rise times of fiber motion were ∼0.165 and 0.085 ms, respectively. For the sake of comparison, the current response obtained with the low-pass filter set at 2.1 kHz was superimposed (dotted line; only the decay response is plotted) on the response obtained with a 4 kHz cutoff frequency (solid line in the right panel). Note that no significant difference in the current magnitude and adaptation rate was observed with the two different rise times.
We also examined adaptation when calcium concentration was altered. Figure 4A shows examples recorded from apical and basal IHCs when the calcium concentration in the bath was reduced from 1.4 mm to ∼50 μm. Lowering extracellular calcium increased the maximum current by a factor of 1.62 ± 0.23 (n = 5) and slowed the low-level adaptation time constant by approximately twofold (2.1 ± 0.78-fold; n = 5 from apical-turn IHCs). The demonstrated susceptibility of adaptation to the calcium content of the medium is another argument in favor of the adequacy of the method of stimulation used here. To explain, if the dynamic properties of the response were dominated by the properties of the TM interposed between the driving fiber and cilia, a change in response with altered calcium would be less likely.
An important experimental variable that can influence the magnitude and rate of adaptation is the onset speed of the displacement step (Wu et al., 1999). In the data presented in Figure 4A, the driving voltage to the piezoelectric stimulator was low-pass filtered with an eight-pole Bessel filter set at 2.1 kHz. This yielded a rise time (10–90%) in the TM-loaded fiber motion of 0.165 ms. To confirm that this is adequate for examining the rate of adaptation, we measured the magnitude and adaptation rate of the MET current from three basal-turn IHCs when the rise time was changed from 0.165 to 0.085 ms. An example is presented in Figure 4B. Despite the fact that current activation was more rapid with the shortened rise time, no significant difference in magnitude and rate of adaptation (0.42 vs 0.44 ms) was observed. This result clearly shows that our stimuli are fast enough to accurately portray fast adaptation in IHCs.
Finally, it is possible to use the measured frequency response (Fig. 3B) to predict the corresponding time response. To this end, the derived frequency response function (shown in the legend of Fig. 3) was generalized from the harmonic representation to a general Laplace transform. The time response of this function (inverse Laplace transform) was then computed with a step input. The obtained linear time response was modified by the Boltzmann function representing the transducer (as in Fig. 1) to account for the nonlinearity of the MET process. The resulting predicted time pattern is superimposed on a set of adaptation functions obtained with DC displacement of the TM. This is shown in Figure 3C (circles and heavy lines). It is apparent that measuring adaptation with sinusoidal inputs yields results very similar to those obtained with the conventional DC displacement of the cilia. The harmonic method of measuring adaptation should allow for a more controllable and precise determination of the frequency-dependent properties of adaptation than the commonly used method that relies on step stimuli. We note that even if the input transducer has a relatively narrow bandwidth, it is possible to adjust its output signal at higher frequencies to provide constant magnitude drive to the hair cells. This is the principal advantage of the steady-state harmonic method.
We have used the hemicochlea preparation previously to obtain transducer currents and receptor potentials from adult gerbil OHCs (He et al., 2004). In the present work, the same approach is used to record these variables from IHCs. In the hemicochlea, hair cells are stimulated through the naturally occurring sequence of BM displacement, organ of Corti micromechanical movements, and shearing motions between the reticular lamina and TM, resulting in ciliary deflection. In other preparations, the stereocilia are usually directly deflected mechanically. We consider the hemicochlea approach to be less susceptible to damage to the transduction apparatus and stimulation artifacts.
We find that for both locations, transducer currents approach 2 nA at large BM displacements toward scala vestibuli, the excitatory direction. The maximum transducer conductance obtained in the present study is 30.1 nS in low Ca2+. This value is 7.1 times greater than that seen from immature IHCs in culture, using 100 Hz stimuli and high Ca2+ (Kros et al., 1992). The differences are likely because of lowering calcium, minimal influence by adaptation (at 500 Hz), possible maturation effects, and the more in vivo-like stimulation in the hemicochlea compared with organotypic cultures. The uniformity of maximum transducer currents and conductances between basal- and apical-turn IHCs is consistent with the morphological data showing that the total number of stereocilia of IHCs is essentially the same along the cochlear length (Lim, 1986). The uniformity of transducer conductance of IHCs is in contrast to OHCs, which show a twofold change in conductance, being larger in the base (He et al., 2004), and to changes seen along the papilla in turtle and OHCs (Ricci et al., 2003, 2005).
When currents are measured using sinusoidal stimulation, it is important to take into account possible adaptation effects. To explain, because of its finite reaction time, the adaptation machinery has a high-pass filter effect on the signal (Fig. 3A). If the stimulus period is long compared with the adaptation time, the latter will influence the response. To consider this in a different light, assume that the signal is very fast, as in a transient or a high-frequency sinusoid. Because the adaptation process has a definite activation time, if the signal is faster than this time, adaptation cannot take place. As the frequency of the input decreases, the rise time (one-quarter cycle) becomes commensurate with the adaptation time and the current–displacement (I–X) curve shifts somewhat along the stimulus axis. This yields a reduced response. As stimulus frequency is further lowered, the shift of the I–X curves becomes complete, and full adaptation ensues, with a concomitant reduction in the response. We are describing here the progression along the function of Figure 3B, from high frequency to low frequency. In the example in Figure 3, the lead–lag network representing the frequency response has a pole at 455 Hz. This frequency is equivalent to the fast time constant that is usually obtained from step responses, which in this example is 0.35 ms. Because even at full adaptation, step responses show nonzero magnitude during the sustained portion of the input, the corresponding frequency-domain representation is an obligatory low-frequency plateau. As we see in the example of Figure 3B, the 500 Hz stimulus used for obtaining the data in Figure 1 is above the corner frequency and the corresponding response should be minimally affected by adaptation. However, the OHC data reported in our previous study were obtained at 100 Hz (He et al., 2004), a frequency below the cutoff frequency. Moreover, adaptation in OHCs appears to be faster and location dependent (Kennedy et al., 2003; Ricci et al., 2005). The consequence of this is that MET channel conductances were significantly underestimated in our previous work, on account of the high calcium in the bathing medium and the low-frequency harmonic stimuli.
If we take our maximal 30.1 nS IHC conductance and the measured single MET channel conductance (Géléoc et al., 1997) of ∼112 pS obtained in 1.3 mm Ca2+ medium, one can estimate the number of channels per tip link. We measured IHC stereocilia numbers in three gerbils, at three cochlear locations: base, middle, and apex. Stereocilia are arranged in three rows with numerous additional microvilli that were not counted. We find no difference in stereocilia numbers along the cochlea. The average number of stereocilia is 68. D. Furness (personal communication) finds an average of 46 cilia for both basal and apical locations of CD-1 mice. Taking our average of 68 cilia in three rows, the number of tip links is 45. From 30.1 nS conductance, 45 tip links, and an assumed 181.2 pS unitary conductance that was obtained by correcting the 112 pS conductance found by Géléoc et al. (1997) from calculating the ratio of low/high calcium bundle conductance, or 112 × 30.1/18.6 = 181.2 pS, one computes 3.7 channels per tip link. Alternatively, if we start from the assumption of two channels per tip link (Denk et al., 1995; Lumpkin and Hudspeth, 1995), yielding 90 channels, we compute a unitary conductance of 344 pS for IHC transducer channels.
Whereas the transducer conductance and maximum IHC transducer current appear uniform along the length of the cochlea, the operating range of the cells is not. As Figure 1 demonstrates, it requires approximately twice as large BM displacement in the apex to reach a given level of excitation. This finding is the same as was shown before for OHCs (He et al., 2004). Thus, the sensitivities (slope, in picoamperes per nanometer) are different for basal and apical IHCs (Fig. 1C). The reason for the difference is found in BM–organ of Corti geometry; a given BM displacement produces larger cilia displacement in the base than in the apex (Dallos, 2003). Because IHC stereocilia are not firmly imbedded in the TM (Lindeman et al., 1971; Lim, 1980), their angular rotation, corresponding to BM displacement, is frequency dependent and difficult to estimate.
We now address the different phase measurements reported here. When the cilia are displaced by direct contact with the TM, this mode of stimulation reveals the dynamic effects of adaptation. In the frequency domain, these are manifested as a modest phase lead between ∼50 and 200 Hz. Because the time constant of adaptation is level dependent, so is the cutoff frequency. We do note here the apparent consistency of measuring adaptation with DC or sinusoidal displacement of the ciliary bundle (Fig. 3C). In addition to the phase lead inherent in the adaptation process, there is a phase lead resulting from the viscoelastic coupling of the cilia to the TM. Because IHC cilia are not imbedded in the bottom surface of the TM (Fig. 2B), under normal stimulating conditions, as in Figure 1, they are displaced by viscous drag of the surrounding fluid. As a result, they respond to some function of BM velocity (Dallos et al., 1972) and thus show a phase lead. When the mechanical stimulus is coupled to the BM, the cilia bundle is stimulated via its normal micromechanical route. In this situation, both the viscoelastic coupling and the adaptation process should produce phase leads. This combined phase is revealed when transducer currents are compared with BM displacement (Fig. 2A). It is remarked that because a derivative relationship was first suggested 34 years ago (Dallos et al., 1972), a large literature has accumulated on assessing relationships between IHC response and BM displacement. When phase leads are obtained and used to support the idea of viscoelastic coupling, it has not been appreciated that the phase also includes that because of adaptation. In fact, we demonstrate here that a frequency-domain description of adaptation yields a low-frequency phase lead of the IHC transducer current. Similar phase lead should be measurable for any hair cell that expresses the adaptation process.
The fastest adaptation rate is always seen for the smallest stimulus. In the present sample, the smallest time constant measured with step inputs was 0.38 ms, corresponding to a cutoff frequency of 419 Hz. Time constants of adaptation in IHCs appear to be longer than those of OHCs, or ∼0.083 ms in the apical turn (Kennedy et al., 2003; Ricci et al., 2005). Although the time constant may be shorter in vivo after adjusting for differences in temperature and the driving force (Kennedy et al., 2003), the time constant of adaptation is uniform along the cochlea, as shown here. This is in contrast to OHCs and turtle hair cells, the adaptation rate of which is cochlear location dependent (Ricci et al., 2003, 2005). It is conceivable that IHCs have a different isoform of MET channels than those in OHCs. IHCs do not require rapid adaptation that is on the same time scale as found in OHCs. Because they are fluid coupled to the TM, their input is already high-pass filtered. Furthermore, if indeed rapid adaptation of OHCs were linked to amplifier action (Chan and Hudspeth, 2005; Kennedy et al., 2005), their need for speed is not duplicated in IHCs, which are not proposed to be active elements in the amplifying feedback loop. It is apparent from this work that, in contrast to amplifying OHCs, MET channel properties of IHCs appear uniform along the cochlear length.
Recently, Beurg et al. (2006) reported that the fast adaptation time constant of neonatal 1HCs was ∼0.45 ms and was invariant at two cochlear locations. Our data are consistent with their findings. However, the maximal amplitude of MET current is significantly larger in the present study, probably reflecting less damage to the mechanotransduction apparatus in the hemicochlea preparation.
This work was supported by National Institutes of Health–National Institute on Deafness and Other Communication Disorders Grants R01 DC 004696 and R21 DC 006039 (D.Z.Z.H.) and R01 DC00089 (P.D.), by the Health Future Foundation of Creighton University, and by the 2005 Sandy and David Marshall Grant in Auditory Science from the National Organization for Hearing Research Foundation. We thank Dr. David Furness for providing mouse inner hair cell (IHC) cilia counts and Ben Currall for providing gerbil IHC cilia counts. Preliminary work was presented in February 2005 at the annual meeting of the Association for Research in Otolaryngology in New Orleans, Louisiana.
Correspondence should be addressed to David Z. Z. He, Hair Cell Biophysics Laboratory, Department of Biomedical Sciences, Creighton University School of Medicine, 2500 California Plaza, Omaha, NE 68178. hed{at}creighton.edu
Ashmore JF
(1987) A fast motile response in guinea-pig outer hair cells: the cellular basis of the cochlear amplifier. J Physiol (Lond) 388:323–347.
Assad JA,
Hacohen N,
Corey DP
(1989) Voltage dependence of adaptation and active bundle movement in bullfrog saccular hair cells. Proc Natl Acad Sci USA 86:2918–2922.
Beurg M,
Evans MG,
Hackney CM,
Fettiplace R
(2006) A large-conductance calcium-selective mechanotransducer channel in mammalian cochlear hair cells. J Neurosci 26:10992–110000.
Bosher SK,
Warren RL
(1978) Very low calcium content of cochlear endolymph, an extracellular fluid. Nature 273:377–378.
Brownell WE,
Bader CR,
Bertrand D,
de Ribaupierre Y
(1985) Evoked mechanical responses in isolated cochlear outer hair cells. Science 227:194–196.
Chan DK,
Hudspeth AJ
(2005) Ca(2+) current-driven nonlinear amplification by the mammalian cochlea in vitro. Nat Neurosci 8:149–155.
Cheatham MA,
Dallos P
(1993) Longitudinal comparisons of IHC ac and dc receptor potentials recorded from the guinea pig cochlea. Hear Res 68:107–114.
(1999) Response phase: a view from the inner hair cell. J Acoust Soc Am 105:799–810.
Crawford AC,
(1989) Activation and adaptation of transducer currents in turtle hair cells. J Physiol (Lond) 419:405–434.
(1991) The actions of calcium on the mechano-electrical transducer current of turtle hair cells. J Physiol (Lond) 434:369–398.
(1985) Response characteristics of mammalian cochlear hair cells. J Neurosci 5:1591–1608.
OpenUrlAbstract
(1986) Neurobiology of cochlear inner and outer hair cells: intracellular recordings. Hear Res 22:185–198.
(1992) The active cochlea. J Neurosci 12:4575–4585.
(2003) Organ of Corti kinematics. J Assoc Res Otolaryngol 4:416–421.
Dallos P,
Billone MC,
Durrant JD,
Wang C,
Raynor S
(1972) Cochlear inner and outer hair cells: functional differences. Science 177:356–358.
Santos-Sacchi J,
Flock Å
(1982) Intracellular recordings from cochlear outer hair cells. Science 218:582–584.
Denk W,
Holt JR,
Shepherd GM,
(1995) Calcium imaging of single stereocilia in hair cells: localization of transduction channels at both ends of tip links. Neuron 15:1311–1321.
Eatock RA
(2000) Adaptation in hair cells. Annu Rev Neurosci 23:285–314.
Eatock RA,
Corey DP,
(1987) Adaptation of mechanoelectrical transduction in hair cells of the bullfrog's sacculus. J Neurosci 7:2821–2836.
(1965) Transducing mechanisms in the lateral line canal organ receptors. Cold Spring Harb Symp Quant Biol 30:133–145.
Freeman DM,
Weiss TF
(1990) Hydrodynamic forces on hair bundles at low frequencies. Hear Res 48:17–30.
Fridberger A,
de Monvel JB,
Zheng JF,
Hu N,
Zou Y,
Ren TY,
Nuttall A
(2004) Organ of Corti potentials and the motion of the basilar membrane. J Neurosci 24:10057–10063.
Géléoc GS,
Lennan GW,
Richardson GP,
Kros CJ
(1997) A quantitative comparison of mechanoelectrical transduction in vestibular and auditory hair cells of neonatal mice. Proc Biol Sci 264:611–621.
He DZZ,
Jia SP,
(2004) Mechanoelectrical transduction of adult outer hair cells studied in a gerbil hemicochlea. Nature 429:766–770.
(2000) Two mechanisms for transducer adaptation in vertebrate hair cells. Proc Natl Acad Sci USA 97:11730–11735.
(1997) Mechanoelectrical transduction and adaptation in hair cells of the mouse utricle, a low-frequency vestibular organ. J Neurosci 17:8739–8748.
Hu XT,
Evans BN,
(1999) Direct visualization of organ of Corti kinematics in a hemicochlea. J Neurophysiol 82:2798–2807.
(1982) Extracellular current flow and the site of transduction by vertebrate hair cells. J Neurosci 2:1–10.
Hudspeth AJ,
(1977) Sensitivity, polarity and conductance change in the response of vertebrate hair cells to controlled mechanical stimuli. Proc Natl Acad Sci USA 74:2407–2411.
Jia S,
He DZ
(2005) Motility-associated hair bundle motion of outer hair cells. Nat Neurosci 8:1028–1034.
He D
(2005) Mechanoelectrical transduction in adult inner hair cells. Assoc Res Otolaryngol Abstr 28:169.
Kachar B,
Altschuler R,
Fex J
(1986) Electrokinetic shape changes of cochlear outer hair cells. Nature 322:365–368.
Kennedy HJ,
(2003) Fast adaptation of mechanoelectrical transducer channels in mammalian cochlear hair cells. Nat Neurosci 6:832–836.
(2005) Force generation by mammalian hair bundles supports a role in cochlear amplification. Nature 433:880–883.
Kros CJ,
Rüsch A,
Richardson GP
(1992) Mechano-electrical transducer currents in hair cells of the cultured neonatal mouse cochlea. Proc R Soc Lond B Biol Sci 249:185–193.
Lim DJ
(1980) Cochlear anatomy related to cochlear micromechanics. A review. J Acoust Soc Am 67:1686–1695.
(1986) Functional structure of the organ of Corti: a review. Hear Res 22:117–146.
Lindeman HH,
Ades HW,
Bredberg G,
Engstrom H
(1971) The sensory hairs and the tectorial membrane in the development of the cat s organ of Corti. A scanning electron microscopic study. Acta Otolaryngol 72:229–242.
Lumpkin EA,
(1995) Detection of Ca2+ entry through mechanosensitive channels localizes the site of mechanoelectrical transduction in hair cells. Proc Natl Acad Sci USA 92:10297–10301.
Müller M
(1996) The cochlear place-frequency map of the adult and developing Mongolian gerbil. Hear Res 94:148–156.
Nuttall AL,
Brown MC,
Masta RI,
Lawrence M
(1981) Inner hair cell responses to the velocity of basilar membrane motion in the guinea pig. Brain Res 211:171–174.
Ohmori H
(1987) Gating properties of the mechano-electrical transducer channel in the dissociated vestibular hair cell of the chick. J Physiol (Lond) 387:589–609.
Ricci AJ,
Wu YC,
(1998) The endogenous calcium buffer and the time course of transducer adaptation in auditory hair cells. J Neurosci 18:8261–8277.
(2000) Active hair bundle motion linked to fast transducer adaptation in auditory hair cells. J Neurosci 20:7131–7142.
(2003) Tonotopic variation in the conductance of the hair cell mechanotransducer channel. Neuron 40:983–990.
(2005) The transduction channel filter in auditory hair cells. J Neurosci 25:7831–7839.
Richter CP,
Edge R,
(1998) Basilar membrane vibration in the gerbil hemicochlea. J Neurophysiol 79:2255–2264.
Russell IJ,
Sellick PM
(1978) Intracellular studies of hair cells in the mammalian cochlea. J Physiol (Lond) 284:261–290.
(1983) Low-frequency characteristics of intracellularly recorded receptor potentials in guinea-pig cochlear hair cells. J Physiol (Lond) 338:179–206.
Cody AR,
(1986a) The responses of inner and outer hair cells in the basal turn of the guinea-pig cochlea and in the mouse cochlea grown in vitro. Hear Res 22:199–216.
Cody AR
(1986b) Mechanosensitivity of mammalian auditory hair cells in vitro. Nature 321:517–519.
Popper AN,
Fay RR
Sewell WF
(1996) in The cochlea, Neurotransmitters and synaptic transmission, eds Dallos P, Popper AN, Fay RR (Springer, New York), pp 503–533.
ter Kuile E
(1900) Die uebertragung der energie von der grundmembran auf die haarzellen. Pflügers Arch 79:146–157.
(1999) Two components of transducer adaptation in auditory hair cells. J Neurophysiol 82:2171–2181.
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Shuping Jia, Peter Dallos, David Z. Z. He
Journal of Neuroscience 31 January 2007, 27 (5) 1006-1014; DOI: 10.1523/JNEUROSCI.5452-06.2007
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Finding her still won't end the crisis. Her unreleased scream could kill her and everyone on Avalon…unless he figures out a way to release it safely. The solution blows them so far apart, Duncan winds back to square one.
Doing whatever he has to—including sacrificing his job with the FID—in order to save her.
Because secretly, he's been in love with her for a decade.


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Afternoon of Jazz
Sunday, April 21st, 2013, 10:26am
Spring Hill, Florida -- April 21, at the Wellington Clubhouse will have some jazz presented by the Hudson Middle School Jazz Band.
The event is free for members of the Hernandon Jazz Society, for non-members tickets cost $10.00.
For more information visit www.hernandojazzsociety.org
HART suggests students apply for youth summit in Washington, D.C.
Friday, April 19th, 2013, 8:25am
Hillsborough County, Florida-- In honor of Earth Day, the Hillsborough Area Regional Transit Authority says high school juniors and seniors are eligible to apply for an upcoming summit in Washignton D.C., where they'll have a chance to learn all about how eco-friendly public transportation can be.
Details on the Generation Green on Board: A Youth Summit to Advance Public Transportation are as follows:
High school students awarded Broadway Stars of the Future Awards by Straz Center
Tuesday, April 16th, 2013, 11:23am
Tampa, Florida-- Two fortunate and talented Florida high school students were recently awarded the David A. Straz, Jr. Center for the Performing Arts' Broadway Stars of the Future Award.
Chandler Morehead and Tim Hart will have the chance to compete this June in the National High School Musical Theater Awards, named after Chairman of the Nederlander Organization, James Nederlander.
Patel Conservatory offers free arts services
Sunday, April 14th, 2013, 8:22pm
The Patel Conservatory at the David A. Straz, Jr. Center for the Performing Arts seeks to provide high-quality arts enhancement programs for local schools and organizations through outreach partnerships. Applications for the 2013-2014 Community Partnerships program are available now and will be accepted through April 26.
Hillsborough County Public Schools to host 2nd Parent University
Sunday, April 14th, 2013, 11:16am
Tampa, Florida-- Parent University, a series of free informational sessions to support the academic life of children, will be held on Saturday, April 27, at Riverview High School from 8:00 a.m. to Noon.
Free Homework and resume help in Hillsborough
Monday, March 25th, 2013, 10:50am
Carrollwood, Florida - The Hillsborough County Public Library Cooperative offers FREE online homework help resources for children, teens and adult learners through Tutor.com
Broadway performer judges Straz contest at Thespian Festival
Saturday, March 23rd, 2013, 11:57am
Tampa, Florida -- Hundreds of high school performers are in Tampa from around the state to participate in the Florida Thespian Festival at the Straz Center downtown!
Broadway performer Quentin Darrington, (Ragtime) is here at the Festival helping to select the winner of the David A. Straz, Jr. Center for the Performing Art's Broadway Stars of the Future Awards. Patel Conservatory Theater Chair Ami Sallee also will judge the contest. Two winners will be chosen to go to New York to compete for scholarship money in the national Jimmy Awards competition.
Walgreens - 3016 W. Gandy Blvd.Tampa 33611


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theremouse

redpajama_set_name: RedPajamaGithub


text:
Breton – person fra antikken.
 Breton (hund) – hunderace fra Bretagne.

pl:Rasy z serii gier The Elder Scrolls#Breton

redpajama_set_name: RedPajamaWikipedia


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What is passive voice?
What is active voice?
Active vs passive voice: why is one considered better than the other?
How to fix passive voice in 2 easy steps
Free Download: Ace your English class
Download our master list of literary and rhetorical devices today!
Blog > Perfecting your Craft	– Posted on May 16, 2019
Passive Voice vs. Active Voice: FINALLY Understand the Difference
When you look over the following sentences, can you identify the ones written in passive voice and the ones using active voice?
The blog post was being published by Reedsy.
Reedsy had published the blog post.
The blog post is published by Reedsy.
The blog post will be published by Reedsy.
If you answered: "The only active sentence is '2,' and the rest are passive" — you are correct! And if you're not sure why that's the right answer? Don't fear: that's why this post is here. In this article, we'll show you exactly how to spot passive voice, how to fix it, and also it's a-okay to use passive voice.
Passive voice vs. active voice: check out the ultimate grammatical showdown here!
A sentence written with passive voice puts emphasis on the person or thing that experiences the action, instead of the person or thing driving the action.
For example, consider this line from Douglas Adams' The Restaurant At The End Of The Universe:
"In the beginning the Universe was created."
The subject of the sentence is "the Universe." The action of the sentence is "created." Because the subject is receiving the action (the creation is happening to the Universe), this is a passive sentence.
Passive sentences are comprised of the auxiliary verb 'to be' and the past tense of the main verb. For example:
"Am / Are / Is" + past verb tense — The dog is walked by his owner.
"Am / Are / Is being" + past verb tense — The dogs are being walked by their owners.
"Was / Were" + past verb tense — The dog was walked by his owner.
"Was / Were being" + past verb tense — The dogs were being walked by their owners.
"Will be" + past verb tense — The dog will be walked by its owner.
"Will have been" + past verb tense — The dog will have been walked by its owner.
"Have / Has been" + past verb tense — The dog has been walked by its owner.
"Had been" + past verb tense — The dog had been walked by its owner.
An important thing to note about passive voice is that it is not the same thing as past tense. Passive voice refers to who the action relates to, while past tense refers to when the action happened. For example, the sentence "The chef cooked dinner" is past tense because "cooked" is the past tense of "cooking." However, the subject of the sentence is the chef, who is performing the action, so the sentence is active, not passive.
There are two types of passive sentences
Short passive, in which the subject or performer of the action is not known. For instance, the above example is short passive because it does not identify who/what the Universe was created by.
Long passive, In which the agent performing the action is known but it is not the subject of the sentence. For instance, the The Restaurant At The End Of The Universe example turns into a long passive sentence if changed to: "In the beginning, the Universe was created by the aliens."
Let's take a look at a few more examples of passive voice to ensure we're all on the same page.
Passive Voice Examples
The following sentences all feature the action happening to the subject.
"He was born with a gift of laughter and a sense that the world was made." — Scaramouche: A Romance Of The French Revolution by Rafael Sabatini
(The action "was born" is happening to the subject "he.")
"Scarlet O'Hara was not beautiful, but men seldom realized it when caught by her charm as the Tarleton twins were." — Gone With The Wind by Margaret Mitchell
(The action "caught by her charm" is happening to a subject "the Tarleton twins.")
"When he was nearly thirteen, my brother Jem got his arm badly broken at the elbow." — To Kill A Mockingbird by Harper Lee
(The action "got his arm badly broken" is happening to the subject "Jem.")
"When Gregor Samsa woke up one morning from unsettling dreams, he found himself changed in his bed into a monstrous vermin." — The Metamorphosis by Franz Kafka
(The second part of this sentence sees the action "changed into a monstrous vermin" happening to subject "Gregor Samsa.")
Active voice is a sentence or clause that puts emphasis on the person or thing that drives the action, instead of the person or thing experiencing the action.
Think of the opening line from George Orwell's 1984:
"It was a bright cold day in April, and the clocks were striking thirteen."
The subject of the sentence is "the clocks." The action of the sentence is "striking." Because the subject is driving the action (the clocks are doing the striking), this is an active sentence.
Check out further instances of active voice at play in the following examples.
Active voice examples
The following sentences all feature the subject enacting some kind of action.
"It was the day my grandmother exploded." — The Crow Road by Iain M. Banks
(The subject "grandmother" is doing the action "exploded").
"Mother died today." — The Stranger by Albert Kamus
(The subject "mother" is doing the action "died.")
"I write this sitting at the kitchen sink." — I Capture the Castle by Dodie Smith
(The subject "I" is doing the action "write" and "sitting.")
"You know, at one time, I used to break into pet shops to liberate the canaries." — Harold and Maud by Colin Higgins
(The subject "I" is doing the action "break into pet shops" and "liberate the canaries.")
It's not a big secret in the world of grammar that passive voice is often considered as bad form. Supposedly, active voice produces stronger, more direct sentences that make your writing feel — surprise, surprise — more active.
But is passive voice actually grammatically incorrect? Nope! There are definitely times when using the passive voice can enhance a statement's clarity.
When to use passive voice
If you are writing something that requires objectivity, like a research paper, passive voice can be your friend: It allows you to more easily avoid personal pronouns and to present information in a that sounds unbiased.
Or maybe you want to leave the perpetrator behind the action unclear. If the action itself or the thing/person receiving the action is more significant than the perpetrator, place emphasis on either of those elements by writing a short passive sentence, leaving the driving force of the action out.
For example, if you write: "The woman was sentenced to five years in jail" — the emphasis here is on the fact that the woman has received a sentence of jail. If you were to write: "The judge sentenced the woman to five years in jail" — the emphasis here is on the judge's ruling instead.
As you can see, passive voice isn't something you need to avoid at all costs: There are times when it's the right choice. However, if you're writing something meant to invite readers in — like a novel, for example — then relying too heavily on passive voice can result in writing that feels a little flat and loses a reader's interest.
To avoid that, let's take a look at how you can fix the use of passive voice in instances where active will serve you better.
To show you the two fool-proof steps to fixing passive voice, we'll use the following passive sentence as an example: "The dress was being made by the tailor."
1. Remove the auxiliary verb
As mentioned, passive sentences often contain some form of the auxiliary verb "to be." In this example, the auxiliary verb is "was being."
Quick note: Not all passive sentences contain an auxiliary verb. For instance, "The dress was made by the tailor" is still passive, even though it doesn't contain any tense of "to be" (in this example, "was being.")
Take the auxiliary verb out and the sentence becomes:
The dress was made by the tailor.
But this is still passive, so the next step is to...
2. Change the subject of the sentence
The subject is currently "the dress" because the action in this sentence is happening to it ("the dress is being made.") The subject of this sentence can be changed by attributing the action to the person performing it — in this case, the tailor. The sentence now becomes:
The tailor made the dress.
Congratulations! The subject is now the action-performer, meaning this sentence is now active!
Let's put these two steps into action, and change a few more passive sentences into active ones.
Passive: The dinner was cooked by the chef.
Active: The chef cooked dinner.
Passive: The flowers were being planted by the gardener.
Active: The gardener was planting the flowers.
Passive: I had been interviewed by the manager.
Active: The manager interviewed me.
Passive: The students had been graded by the teacher.
Active: The teacher was grading the students.
Passive: The book was written by the author.
Active: The author wrote the book.
Passive: The house is being built by the construction workers.
Active: The construction workers are building the house.
Passive voice vs. active voice: finally understand the difference for once and for all!
We hope we've helped you understand how to identify and fix passive voice! If you feel like you could still use a hand, you can also turn to automatic passive voice checkers, such as Hemingway, Passive Voice Detector, Analyze My Writing — which are all free and web-based. Simply copy and paste the writing you want to check, and the tool will highlight instances of passive voice for you.
How do you feel about the "active voice is better than passive voice" rule? Leave any thoughts or questions in the comments below!
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The University of Denver had existed for less than 30 years when the decision was made to relocate the campus from its original site downtown to a place several miles to the south, a move completed in 1892. The town of South Denver grew up around University Park. At first both a university town and a neighboring suburb of Denver, South Denver was soon annexed into the larger city. In the coming decades, South Denver would establish its own residential and business identities apart from the influence of the University of Denver, known as DU, though it would remain a central character in the shaping and growth of the community. In the 21st century, University Park and South Denver have flourished with beautiful homes, attractive parks, and highly rated schools.
In the Rocky Mountain West, Denver is considered the big city. Yet its urban core consists of numerous neighborhoods developed in the late 19th century that act today as virtual small towns. South-central Denver's Washington Park is one of those "small towns," and its name refers both to a 166-acre historic park and to the surrounding blend of residential and commercial neighborhoods. Cited as a model for new urbanism, this area serves as an enduring example of the City Beautiful movement. Touted in the late 19th century for its "rapid transit," clean air, and pure water, the area once known as Broadway Terrace, Myrtle Hill, and the Miracle Mile of South Denver continues to serve as a recreational mecca for Denverites. Over a span of 100 years, it has transformed from prairie to potato fields to "posh."
University Park was founded in the 1880s when the University of Denver (Colorado Seminary) moved from downtown Denver to land donated by potato farmer Rufus Clark. The University, founded by Methodists, wanted to escape the urban blight of the city and build an oasis for education. Liquor production or consumption was not allowed, and though today the area has many pubs a number of home mortgages to this day contain old covenants forbidding the making or selling of spirits. Around University Park grew the town of South Denver, which was annexed to the city of Denver in the early twentieth century. For many years in the late 1800s the primary employer was the University of Denver, but over time others moved into the area for its attractive homes and well respected schools. The area has traditionally been upper middle class and has enjoyed one of the lowest crime rates in the city. At the geographic center of University Park is Observatory Park, named for the famous Chamberlain Observatory, built in the 1890s and still fully operational with popular public viewing nights. In the early part of the century Colorado Governor Henry Buchtel lived in the park, as did a number of famed early DU faculty such as Ammi Hyde, who beat the freshman boys in an annual foot race well into his 90's. The area boomed after World War II as many from other parts of the country who were stationed in Colorado chose to remain and make it their home. The area has remained prosperous and continues to grow, sharing in the overall success that the Denver metro area has experienced.
Nowhere better than in the history of its railroads is the growth of the Old West revealed, and for Colorado the development of the Denver and Rio Grande Western epitomizes the changes that took place between 1870 and the present. Robert G. Athearn's intimate knowledge of the West has enabled him to write a gripping account of the famous narrow-gauge Denver and Rio Grande as it inched its way south, then turned west into the Rockies. By f1883 it had joined with the Rio Grande Western to become Colorado's only line across the mountains. The Dotsero Cutoff and the six-mile Moffat Tunnel put Denver on a transcontinental line for the first time. Twelve maps and fifty-five illustrations help tell the story.
Where are Colorado's very best campgrounds? Gil Folsom's indispensible guide takes the guesswork out of sorting through the confusing jumble of campground lists found in most guides. Whether you're pitching your tent or parking your RV, this guide is all you'll ever need. Color-coded regions and practical information regarding directions, facilities, and facts about the area make planning a snap. Full-color scenic photographs will whet your appetite before you even leave home! Let Gil lead you to Colorado's 100 best -- in addition to the 334 other campgrounds that make Colorado one of the best camping states in the country.
Images of Baseball: Baseball in Denver shares the city's prominent role in America's great game. The lore of baseball's first pioneers plays out in a real-life soap opera for this Western city. From the early Hall-of-Fame players to the storied baseball-talent barons of Denver's primitive days, baseball has always been on the forefront of the Denver sports horizon. From Tinker to Satchel Paige to "The Babe" himself, the Mile High City has been a barnstormer's oasis in a town that was nothing short of the Wild West. The Denver Post Tournament and the rich history of the Denver Bears are highlighted, as well as the many fields and landmarks throughout the city. With the inception of the Colorado Rockies, Denver once again set the stage for big-league baseball, which many of Denver's local baseball legends have been no stranger to.
Rocky Mountain News dining critic reviews over 200 restaurants in the Denver, Colorado area. Includes indexes by type of dining, cuisine and location. Also lists top picks and specialty food sources.