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Yoshizaki Takahiro - - 2013
BACKGROUND: Misalignment of circadian systems is detrimental to human health. However, only a few studies have examined the influence of late meals on the human circadian system. The purpose of this study was to investigate whether delayed meals affect circadian rhythm as assessed by heart rate variability (HRV). METHODS: Seven ...
Chuang Wen-Hsien - - 2012
ABSTRACT: Study Design. The biomechanical effects of disc degeneration and hybrid fixation on the transition and adjacent segments were evaluated using a numerical approach.Objective. This study aimed to evaluate the rigidity-rising effects of the dehydrated disc and bridged fixator on the kinematic and mechanical redistribution of the transition and adjacent ...
Wang Wenhai - - 2012
The current study aimed to compare the biomechanics of the L3-S1 spine segment treated either by fusion or total disc replacement (TDR) using the TRIUMPH(®) Lumbar Disc (Globus Medical, Audubon, PA). A validated three-dimensional, nonlinear finite element model (FEM) of L3-S1 was altered at L4/L5 by fusion and implantation of ...
Arakawa Hisayuki - - 2012
The relationship between Secchi disc depth and amount of suspended material in seawater varies depending on the particular marine area. To identify the cause of this dependence, we calculated the apparent contrast (C (SD)) at each Secchi disc depth in different coastal sea areas. When the turbidity from the surface ...
Kim Jaehyun - - 2012
Mechanical stress on the intervertebral disc (IVD) may contribute significantly to IVD degeneration, although its pathomechanism has not been fully understood. The purpose of this study was to test the hypothesis that sustained application of static shear force would result in IVD degeneration with minimum injury. We applied shear force ...
Mehta Jwalant S - - 2012
The purpose of this study is to assess the degenerative changes in the motion segments above a L5S1 spondylolytic spondylolisthesis and to view these in light of the retrolisthesis in the segment immediately above the slip. A spondylolytic spondylolisthesis causes an abnormal motion and predisposes to degenerative changes at the ...
Christensen-Dalsgaard Jakob J Institute of Biology, University of Southern Denmark, Campusvej 55, 5230 Odense, - - 2012
Turtles, like other amphibious animals, face a trade-off between terrestrial and aquatic hearing. We used laser vibrometry and auditory brainstem responses to measure their sensitivity to vibration stimuli and to airborne versus underwater sound. Turtles are most sensitive to sound underwater, and their sensitivity depends on the large middle ear, ...
Bisschop Arno - - 2012
PURPOSE: Reduced strength and shear stiffness (SS) of lumbar motion segments following laminectomy may lead to instability. The purpose of the present study was to assess a broad range of parameters as potential predictors of shear biomechanical properties of the lumbar spine. METHODS: Radiographs and MRI of all lumbar spines ...
Hein Elisabeth - - 2012
How is the visual system able to maintain object identity as the objects or the eyes move? While many early studies have shown small or no influence of feature information on this correspondence process, more recent studies have shown large feature effects. Here we investigated if this incongruity might be ...
Xi Shuang - - 2011
Large quantities of silica nanowires were synthesized through thermal treatment of silicon wafer in the atmosphere of N<sub>2</sub>/H<sub>2</sub>(5%) under 1200 °C with Cu as catalyst. These nanowires grew to form a natural bright-white mat, which showed highly diffusive reflectivity over the UV-visible range, with more than 60% at the whole ...
Henderson Eric R - - 2011
Familial dysautonomia (FD) is a rare neurological disease with autosomal recessive inheritance and is associated with severe kyphoscoliosis. Investigators have reported subjective observation of decreased cervical motion and high rates of proximal instrumentation failure in this population. A radiographic study of sagittal plane cervical spine motion was performed with 15 ...
Shelton David P - - 2011
A permanent magnet stepper motor is modified to hold a dichroic polarizer inside the motor. Rotation of the polarizer by 90° ± 0.04° is accomplished within 80 ms. This device is used for measurements of the intensity ratio for two orthogonal linear polarized components of a light beam. The two ...
Gao Bin - - 2011
In a transmittance spectrum of air etalon composed of ITO-coated glass plates, stronger spectral modulation is observed by using a focused white-light incident beam compared with that by using a conventionally collimated beam. The light source is a single commercial light-emitting diode. An angular integrated multiple-beam Fabry-Perot model is proposed ...
Brockmeyer Alison M AM Washington University School of Medicine, USA. - - 2011
Difficulty understanding in background noise is a common complaint of cochlear implant (CI) recipients. Programming options are available to improve speech recognition in noise for CI users including automatic dynamic range optimization (ADRO), autosensitivity control (ASC), and a two-stage adaptive beamforming algorithm (BEAM). However, the processing option that results in ...
Swanson William H WH School of Optometry, Indiana University, Bloomington, Indiana 47405-3680, USA. - - 2011
Perimetry is used clinically to assess glaucomatous ganglion cell loss. It has been proposed that frequency-doubling stimuli are better than the conventional size III perimetric stimulus in preferentially stimulating magnocellular (M) versus parvocellular (P) ganglion cells. However, little is known about how primate ganglion cells respond to perimetric stimuli. The ...
Falk Ben B Department of Psychology, University of Maryland, College Park, MD 20742, - - 2011
This study examined behavioral strategies for texture discrimination by echolocation in free-flying bats. Big brown bats, Eptesicus fuscus, were trained to discriminate a smooth 16 mm diameter object (S+) from a size-matched textured object (S-), both of which were tethered in random locations in a flight room. The bat's three-dimensional ...
Clark Ross A - - 2011
Objectives: Commercial timing light systems (CTLS) provide precise measurement of athletes running velocity, however they are often expensive and difficult to transport. In this study an inexpensive, wireless and portable timing light system was created using the infrared camera in Nintendo Wii hand controllers (NWHC). Design: System creation with gold-standard ...
Sullivan John M - - 2011
INTRODUCTION: Previous studies have shown that increased risk in darkness is particularly great for pedestrian crashes, suggesting that attempts to improve headlighting should focus on factors that likely influence those crashes. The current analysis was designed to provide information about how details of pedestrian crashes may differ between daylight and ...
Hackett Deborah A - - 2011
Evidence for ganglion cell visual dysfunction in human glaucoma is often indirect, being either measured at the cellular level in animal models or being inferred from the pooled responses of a large number of ganglion cells in human observers. Rarebit perimetry (RBP) uses repeated, intense (150 cd/m2) stimuli-whose size is ...
Price Richard B - - 2011
Purpose: To quantify the effect of distance on the irradiance and beam homogeneity from 4 curing lights. Methods: Four light-emitting diode curing lights were evaluated: Fusion, Bluephase 16i, Demi and FlashLite Magna. The irradiance at the centre of the light beam (ICB) was measured at 1.0 to 9.0 mm from ...
Shmueli Karin - - 2011
Recent high-field MRI studies based on resonance frequency contrast have revealed brain structure with unprecedented detail. Although subtle magnetic susceptibility variations caused by iron and myelin seem to be important to this contrast, recent research on protein solutions suggests that chemical exchange between water and macromolecular protons may contribute substantially ...
O'Dwyer D P - - 2010
Conical diffraction of linearly polarised light in a biaxial crystal produces a beam with a crescent-shaped intensity profile. Rotation of the plane of polarisation produces the unique effect of spatially moving the crescent-shaped beam around a ring. We use this effect to trap microspheres and white blood cells and to ...
Bowker Colleen - - 2010
A research study has been performed to determine the ultraviolet (UV) fluence-response of several target non-pathogenic microorganisms to UV light emitting diodes (UV-LEDs) by performing collimated beam tests. UV-LEDs do not contain toxic mercury, offer design flexibility due to their small size, and have a longer operational life than mercury ...
Quinteiro G F - - 2010
We theoretically investigate the effect of inhomogeneous light beams with (twisted light) and without (plane-wave light) orbital angular momentum on semiconductor-based nanostructures, when the symmetry axes of the beam and the nanostructure are displaced parallel to each other. Exact analytical results are obtained by expanding the off-centered light field in ...
Jaekl Philip M - - 2010
Although it has been previously reported that audiovisual integration can modulate performance on some visual tasks, multisensory interactions have not been explicitly assessed in the context of different visual processing pathways. In the present study, we test auditory influences on visual processing employing a psychophysical paradigm that reveals distinct spatial ...
Leguire L E - - 2011
The purpose of this study was to ascertain whether visual acuity or contrast sensitivity function (CSF) is proportional to visual cortical function based on fMRI volume and level of activation or Z-score. Forced choice procedures were utilized to measure the monocular log minimal angle of resolution (logMAR) visual acuity and ...
Hanke Frederike D - - 2011
In this study, the contrast sensitivity function (CSF) of one harbor seal was determined behaviorally in a go-/no-go-experiment at an ambient light of 0.9 lx in air. Contrast sensitivity was assessed as the reciprocal value of the threshold contrast for spatial frequencies varying between 0.03 and 1.5 cycles/deg, which were displayed ...
Ling Sam - - 2010
When dissimilar images are presented to the two eyes, the human visual system lapses into binocular rivalry, a unique perceptual state characterized by stochastic alternations in dominance of one of the two source images over the other. Probe targets delivered to an eye during suppression phases are more difficult to ...
Kingdom Frederick A A - - 2011
The past quarter century has witnessed considerable advances in our understanding of Lightness (perceived reflectance), Brightness (perceived luminance) and perceived Transparency (LBT). This review poses eight major conceptual questions that have engaged researchers during this period, and considers to what extent they have been answered. The questions concern 1. the ...
Boogaard Hanna - - 2010
Recent interest has focused on the health effects of ultrafine particles because of the documented toxicity and the larger concentration contrast near motorways of UFP than for PM10 or PM2.5. There are only few studies that have measured UFP at inner-city streets simultaneously with other PM components. The aim of ...
van der Kooij Katinka - - 2010
We investigated whether a shape contrast bias is caused by local contrast enhancement or by a global mechanism. In a baseline condition, observers performed a shape discrimination task on an isolated hinged plane. But in the experimental conditions, five dihedral surfaces, of which we varied the dihedral angle distribution, were ...
Gruppetta Steve - - 2010
A differential amplitude scanning system for ophthalmoscopy is described theoretically. The differential scanning ophthalmoscope (DSO) samples the retina with two laterally displaced spots. The signal measured is the difference between the irradiance from these two locations. The theoretical analysis of the DSO shows it offers increased contrast at high spatial ...
Gomes B D - - 2010
Transient visual evoked cortical potentials (VECP) were recorded from the scalp of healthy normal trichromats (n = 12). VECPs were elicited by onset/offset presentation of patterned stimuli of two kinds: isochromatic luminance-modulated, and equiluminant red-green modulated, sine wave gratings. The amplitude and latency of the major onset components of the ...
Shapiro Arthur G AG American University, Washington, DC 20016, USA. - - 2010
Recent work in the Shapiro laboratory has suggested that the visual response to changes in chromaticity/luminance can be separated from the visual response to changes in spatial contrast. Here, we examine how spatial edges affect the relative perceptual weighting of these two types of responses. In the experiments, we separate ...
Eperjesi Frank - - 2011
Yellow filters are sometimes recommended to people with low vision. Our aim was investigate the effects of three commercial yellow filters on visual acuity and contrast sensitivity (with and without glare) and reading (without glare) under conditions of forward light scatter (FLS). Fifty-five healthy subjects were assessed with Corning Photochromic ...
Almoqbel Fahad M - - 2011
There are many parameters that may impact the thresholds obtained with sweep visually evoked potentials (sVEP), yet a number of these parameters have not been systematically studied, and there is no recognised standard for sVEP recording. In this study, the effects of electrode placement, temporal frequency, sweep direction, presence of ...
Koh Hwan Cui - - 2010
Adolescents with autism spectrum disorders (ASD) and typically developing (TD) controls underwent a rigorous psychophysical assessment that measured contrast sensitivity to seven spatial frequencies (0.5-20 cycles/degree). A contrast sensitivity function (CSF) was then fitted for each participant, from which four measures were obtained: visual acuity, peak spatial frequency, peak contrast ...
Hess Robert F - - 2010
Although there is general agreement that the fMRI cortical response is reduced in humans with amblyopia, the deficit is subtle and has little correlation with threshold-based psychophysics. From a purely contrast sensitivity perspective, one would expect fMRI responses to be selectively reduced for stimuli of low contrasts. However, to date, ...
Wei D H - - 2010
Periodic Ag line arrays with different line pitches from 500 nm to 950 nm on ITO coated glass substrates have been fabricated by using electron-beam lithography (EBL) technique for studying the color light guide in a display system. The patterned Ag line array is used as a light outcoupling and ...
O'Donell Beatriz M - - 2010
We present a series of experiments exploring the effect of chromaticity on reaction time (RT) for a variety of stimulus conditions, including chromatic and luminance contrast, luminance, and size. The chromaticity of these stimuli was varied along a series of vectors in color space that included the two chromatic-opponent-cone axes, ...
Beaufrère Hugues - - 2010
Contrast fluoroscopy is a valuable tool to examine avian gastrointestinal motility. However, the lack of a standardized examination protocol and reference ranges prevents the objective interpretation of motility disorders and other gastrointestinal abnormalities. Our goals were to evaluate gastrointestinal motility in 20 Hispaniolan Amazon parrots (Amazona ventralis) by contrast fluoroscopy. ...
van der Smagt Maarten J - - 2010
We investigated whether center-surround interactions affect perceived speed in a manner similar to their effects on direction discrimination thresholds [e.g. Tadin, D., Lappin, J. S., Gilroy, L. A., & Blake, R. (2003). Perceptual consequences of center-surround antagonism in visual motion processing. Nature, 424, 312-315]. Observers were asked to match the ...
Freeman Daniel K - - 2010
To accommodate the wide input range over which the visual system operates within the narrow output range of spiking neurons, the retina adjusts its sensitivity to the mean light level so that retinal ganglion cells can faithfully signal contrast, or relative deviations from the mean luminance. Given the large operating ...
Bosten J M - - 2010
Individuals differ in their susceptibility to simultaneous contrast. Are the underlying differences in neural machinery conserved across different stimulus dimensions? We measured the extent to which 101 subjects perceived simultaneous contrast on the dimensions of luminance, colour, luminance contrast, colour contrast, orientation, spatial frequency, motion and numerosity. Individual differences showed ...
Connolly Desmond M - - 2010
INTRODUCTION: Visual performance in dim light is compromised by lack of oxygen (hypoxia). The possible influence of altered oxygenation on foveal contrast sensitivity under mesopic (twilight) viewing conditions is relevant to aircrew flying at night, including when using night vision devices, but is poorly documented. METHODS: Foveal contrast sensitivity was ...
Sartucci F F Department of Neuroscience, Unit of Neurology, Pisa University Medical School, Pisa, Italy. - - 2010
Visuo-spatial disturbances could represent a clinical feature of early stage Alzheimer's disease (AD). The magnocellular (M) pathway has anatomo-physiological characteristic which make it more suitable for detecting form, motion and depth compared with parvocellular one (P). Aim of our study was to evaluate specific visual subsystem involvement in a group ...
Sund Patrik - - 2010
The DICOM part 14 greyscale standard display function provides one way of harmonising image appearance under different monitor luminance settings. This function is based on ideal observer conditions, where the eye is always adapted to the target luminance and thereby also at peak contrast sensitivity. Clinical workstations are, however, often ...
Tajima Satohiro - - 2010
Spatial context in vision has profound effects on neural responses and perception. Recent animal studies suggest that the effect of surround on a central stimulus can dramatically change its character depending on the contrast of the center stimulus, but such a drastic change has not been demonstrated in the human ...
Risner Michael L - - 2010
Retinal ganglion cells (RGCs) are highly sensitive to changes in contrast, which is crucial for the detection of edges in a visual scene. However, in the natural environment, edges do not just vary in contrast, but edges also vary in the degree of blur, which can be caused by distance ...
Giacomelli Giovanni - - 2010
PURPOSE: To investigate the reliability of the Reading Explorer (REX) charts and to assess the impact of text contrast reduction (1.5 cycle/degree) on reading speed in subjects with normal and low vision. METHODS: Standard visual acuity (ETDRS charts), reading speed (MNread charts), and contrast sensitivity (Pelli-Robson charts) measurements were obtained ...
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