Fragile X syndrome (FXS) is characterized by the impairment of the magnocellular/dorsal visual system. In this study, we explored how fragile X protein (FMRP) expression may affect visual functions in healthy participants. The percentage of FMRP-positive lymphocytes was measured using a rapid antibody test in blood smears of 100 male ...

The source characteristics of biosonar signals from sympatric killer whales and long-finned pilot whales in a Norwegian fjord were compared. A total of 137 pilot whale and more than 2000 killer whale echolocation clicks were recorded using a linear four-hydrophone array. Of these, 20 pilot whale clicks and 28 killer ...

A 51-years-old patient with polyadenopathies presents a non monotypic chronic lymphocytic leukemia (CLL): lymphocytes B CD5+, CD23+, CD22-,CD79b dim, FMC7- express κ (71%) and λ (21%) light chains withoutcoexpression. The caryotype shows two clones with one in evolution. Lymphoid clonality analysis by PCR (polymerase chain reaction) of the heavy and ...

This study examined the role of broadly distributed sensor populations in chemosensory searching, especially cross-stream heading adjustment. We used three-dimensional laser-induced fluorescence to collect chemical concentration data simultaneously with behavior observations of actively tracking blue crabs (Callinectes sapidus). Our analysis indicates that the spatial distribution of the odorant concentration field ...

Rhodopsin is a canonical member of the family of G protein-coupled receptors, which transmit signals across cellular membranes and are linked to many drug interventions in humans. Here we show that solid-state (2)H NMR relaxation allows investigation of light-induced changes in local ps-ns time scale motions of retinal bound to ...

NMR order parameters are calculated from molecular dynamics computer simulations of ubiquitin and the apo (Ca(2+)-free) state of calbindin D(9k). Calculations are performed in an expanding reference frame so as to discriminate between the effects of short- and long-range motions. This approach reveals that the dominant contributions to the order ...

Analysis of sagittal vertical axis (SVA) on lateral spine radiographs in healthy normal volunteers. To determine the optimal arm position with the smallest negative shift in SVA. Radiographic visualization of spinal and pelvic sagittal morphology is difficult with the participant in a relaxed standing position because of interference from the ...

Samples of three humic acids and one fulvic acid with 1% loading of benzene-d(6) in sealed glass tubes have been studied with solid-state deuterium quadrupole-echo nuclear magnetic resonance spectroscopy. Calculated spectra combining three motional models, two isotropic models and a third more restricted small-angle wobble (SAW) motional model, are fit ...

We studied the effect of UV light (240-390 nm) in doses of 75.5-4530 J/m(2)on functional properties and level of intracellular messengers (cAMP, Ca(2+), NO) in lymphocytic cells of the peripheral blood. Correcting effects of UV light in a dose of 151 J/m(2)on cytotoxic activity of lymphocytes against Ehrlich ascetic carcinoma ...

During backstroke, an optimum shoulder entry angle of 180° has been anecdotally suggested; however, this has yet to be investigated biomechanically. The aim of this study was to quantify shoulder entry angles for advanced and intermediate backstroke swimmers. Six advanced (season's best <150 s) and six intermediate (season's best >160 s) 200-m backstroke swimmers ...

The internal rotations and interconformational jumps of ibuprofen in the solid state are fully characterized by the simultaneous analysis of a variety of low- and high-resolution NMR experiments for the measurement of several (13) C and (1) H spectral and relaxation properties, performed at different temperatures and, in some cases, ...

Experiment I examined detection and discrimination of monaural four-tone sequences composed of 400-, 500-, and 625-Hz sinusoids. In the baseline conditions, the masker was monaural composed of 25-Hz-wide bands of random noise centered on 320, 400, 500, 625, and 781 Hz. In the binaural masking release conditions, the noise was ...

OBJECTIVE: With advanced electroencephalography (EEG) technology, 'wideband EEG' ranging from slow shift to high frequency oscillation (HFO) is clinically available to study human epileptogenesis. The purpose of our study is to clarify the relationship between slow shift, HFO and conventional electrocorticographic (ECoG) change. METHODS: A patient with right temporal lobe ...

We have recently demonstrated that persistent, passive exposure of adult cats to bandlimited tone pip ensembles at moderate intensities (˜70 dB SPL) leads to a long-term suppression of neural activity in auditory cortex, in the absence of hearing loss. With wideband ensembles (4-20 kHz), the suppression is limited to the ...

A method for characterizing the noise figure of preamplifiers at NMR frequencies is presented. The noise figure of preamplifiers as used for NMR and MRI detection varies with source impedance and with the operating frequency. Therefore, to characterize a preamplifier's noise behavior, it is necessary to perform noise measurements at ...

PURPOSE: To determine whether perceptual adaptation improves voice gender discrimination of spectrally shifted vowels, and if so, which acoustic cues contribute to the improvement. METHOD: Voice gender discrimination was measured for ten normal-hearing subjects, during 5 days of adaptation to spectrally shifted vowels, produced by processing the speech of five ...

The binaural beat has been used for over 100 years as a stimulus for generating the percept of motion. Classically the beat consists of a pure tone at one ear (e.g., 500 Hz) and the same pure tone at the other ear but shifted upward or downward in frequency (e.g., ...

Falling onto the outstretched hand is the most common cause of upper extremity injury. This study develops an experimental model for evaluating the shoulder load during a simulated forward fall onto one hand with three different forearm axially rotated postures, and examines the shoulder abduction angle and shoulder flexion angle ...

The underwater hearing sensitivity of a young male harbor porpoise for tonal signals of various signal durations was quantified by using a behavioral psychophysical technique. The animal was trained to respond only when it detected an acoustic signal. Fifty percent detection thresholds were obtained for tonal signals (15 frequencies between ...

The tendency to hear a sequence of alternating low (L) and high (H) frequency tones as two streams can be increased by a preceding induction sequence, even one composed only of same-frequency tones. Four experiments used such an induction sequence (10 identical L tones) to promote segregation in a shorter ...

Harmonic analysis was used to characterize the rabbit flicker ERG elicited by sinusoidally modulated full-field stimuli under light-adapted conditions. The frequency-response function for fundamental amplitude, derived from Fourier analysis of the ERG waveforms, exhibited two limbs, with an amplitude minimum at approximately 30Hz, and a high-frequency region peaking at around ...

Our goal was to challenge both normal controls and patients with seasonal affective disorders (SAD) to various light histories and then measure their retinal response modulation using the electroretinogram (ERG) in both winter and summer. In winter and summer, 11 normal controls and 12 SAD patients were exposed to three ...

In normal subjects the later part of the cone a-wave to a brief flash increases in amplitude after 50-100 ms darkness due to a contribution from secondary hyperpolarising cells. We recorded these responses along with clinical ON and OFF ERGs in patients with inner retinal dysfunction to see if this ...

It is well established that nitric oxide (NO) participates in retinal signal processing through stimulation of its receptor enzyme, soluble guanylyl cyclase (sGC). However, under pathological conditions such as uveoretinitis, diabetic or ischemic retinopathy, elevated NO concentrations may cause protein S-nitrosation and peroxynitrite formation in the retina, promoting cellular injury and ...

In response to progressively stronger flashes delivered against a rod saturating background light, the amplitude of the photopic ERG b-wave first increases, reaches a maximal value (V (max)) and then decreases gradually to a plateau where the amplitude of the b-wave equals that of the a-wave, a phenomenon known as ...

We investigated the possibility of performing electroretinography (ERG) in non-pharmacologically dilated eyes using brighter flash (time-integrated) luminance. Photopic (N = 26; background 25.5 cd·m(-2), white LED flashes) and scotopic ERG (N = 23, green LED flashes) luminance response functions were obtained simultaneously in a dilated (DE) and non-dilated eye (NDE). In the NDE, photopic V ...

This study characterizes differences in human ERGs based on ocular pigmentation. Light- and dark-adapted luminance-response (LR) series for a-, b- and i-waves and light-adapted oscillatory potentials (OPs) were recorded in 14 healthy volunteers (7 blue-eyed Caucasians; 7 brown-eyed Asians, aged 20-22 years). Amplitude interpolations were by logistic growth (Naka-Rushton), Gaussian or the ...

The chirp-evoked ABR has been regarded as a more synchronous response than the click-evoked ABR, referring to the belief that the chirp stimulates lower-, mid-, and higher-frequency regions of the cochlea simultaneously. In this study a variety of tools were used to analyze the synchronicity of ABRs evoked by chirp- ...

Full-field electroretinograms were recorded from five normal human subjects using white light (mean luminance: 250 cd/m2) sine wave stimuli at different frequencies and contrasts. In agreement with previous studies, we found that the amplitude of the fundamental component displayed a dip at about 12 Hz, coinciding with a maximum in ...

The paradigm of sine-wave electrical stimuli has been used for sensory neurological assessment in humans. In the present study, we applied the paradigm to the dog for the quantitative assessment of sensory function. Sine-wave electrical current stimuli at frequencies of 2000, 250, and 5Hz were delivered to bipolar electrodes attached ...

We studied the contribution of retinal on and off-mechanisms in the multifocal electroretinogram (mfERG) by measuring responses to saw tooth stimuli. Six healthy subjects participated in this study. Rapid-on and rapid-off sawtooth stimuli with a period of 427 ms were presented in a multifocal pattern composed of 19 hexagons. The ...

PURPOSE: This study aims to ascertain the characteristics of the response triggered by the global flash multifocal electroretinogram (MOFO mfERG) under various combinations of global and focal flash luminance, and to determine the optimal conditions for this measurement. METHODS: Ten normal subjects with mean age 23.2 yrs (+/- 1.14 yrs) ...

This demonstration shows how standing waves on a spring can be generated by having two people simulate boundary conditions. If one person holds the end of the spring at rest while the other drives the opposite end in an up and down motion, the spring will begin to oscillate. By ...

To evaluate the effects of induced hypercapnia on the electroretinogram (ERG) in beagle dogs anaesthetized with isoflurane and sevoflurane. Binocular, full-field flash photopic and scotopic ERGs were obtained from six healthy neutered female beagle dogs. In order to determine Vmax and the photopic negative response (PhNR), photopic ERG luminance-response curves ...

BACKGROUND: The aim of our study was to assess the effect of physical exercise with increasing intensity on neuroretinal activity in healthy subjects (n = 30). METHOD: We analysed the amplitude and implicit time of b-wave electroretinogram (ERG) responses in two experiments: (1) for a scotopic blue 10 Hz flicker ...

We demonstrate ultrabroad-bandwidth low-power frequency conversion of continuous-wave light in a dispersion engineered silicon nanowaveguide via four-wave mixing. Our process produces continuously tunable four-wave mixing wavelength conversion over two-thirds of an octave from 1241-nm to 2078-nm wavelength light with a pump wavelength in the telecommunications C-band.

When required to identify the orientation of an item outside the center of the visual field, the mean orientation predicts performance better than the orientation of any individual item in that region. Here I examine whether the visual system also preserves the variance of orientations in these so-called "crowded" displays. ...

A simple experiment with a rotating office chair demonstrates that the extent of counter-rotation we experience when imposed rotation has stopped is the same as the angular inaccuracy of pointing to a previously fixated object. This suggests that our conscious percept of rotation and the updating signal for the egocentric ...

A middle-aged asymptomatic woman presented with multiple yellow-white flecks in the retinal pigment epithelium (RPE) affecting both fundi in a symmetrical pattern. The lesions were distributed around the posterior pole and midperiphery but sparing the macula, a picture similar to what was defined by Gass as benign fleck retina. Visual ...

Experience has long-term effects on perceptual appearance (Q. Haijiang, J. A. Saunders, R. W. Stone, & B. T. Backus, 2006). We asked whether experience affects the appearance of structure-from-motion stimuli when the optic flow is caused by observer ego-motion. Optic flow is an ambiguous depth cue: a rotating object and ...

The effect of blockade of voltage-gated sodium (Na(v)) channels by tetrodotoxin (TTX) on the V-log I function of the ERG b- and d-waves was investigated in light and dark adapted frog eyecups. TTX diminished the b- and d-wave amplitude under both conditions of adaptation at all stimulus intensities except for ...

Classical apparent motion stimuli exhibit an inherent ambiguity with respect to the onsets and offsets of the stimulus elements. Sigman and Rock (1974, Perception 3 9-28) presented evidence suggesting that occlusion cues are used to resolve this ambiguity. We present results from experiments designed to further test predictions of this ...

BACKGROUND: ZK 200775 is an antagonist at the alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptor and had earned attention as a possible neuroprotective agent in cerebral ischemia. Probands receiving the agent within phase I trials reported on an alteration of visual perception. In this trial, the effects of ZK 200775 on the visual system ...

PURPOSE: To study the influence of retinal adaptation on oscillatory potential (OP) using repeated-flash electroretinography. METHODS: Subjects were 28 adult eyes with normal retinas. Four stimuli (four flashes) of white light from a light-emitting diode built into a contact lens that also served as the recording electrode were presented at ...

We report the observation of a remarkably strong coupling between light and a multinode-type exciton. The observed radiative decay time reaches the order of 100 fs, which is much faster than the dephasing process of nonradiative scattering. In this high-speed superradiance, the light wave and the excitonic wave in a ...

To assess the safety and to quantify the effects of a single application of all-trans-N-retinylacetamide on the rat retina measured by electroretinography (ERG). Brown Norway rats were assigned to either a control group (n = 13) or to one of the three groups treated with a single intra-peritoneal dose of ...

AIMS: In optic nerve hypoplasia (ONH), the extent of functional loss of retinal ganglion cells cannot be determined by ophthalmoscopic examination. The prognostic value of visual electrodiagnostic tests in infants and toddlers with ONH was assessed by comparison with visual outcome. METHODS: 85 participants with ONH had electroretinogram (ERG) and ...

When the eye is stimulated by a flickering light, the electroretinogram (ERG) and other electrophysiological responses in the visual pathway often exhibit period doubling. This phenomenon is manifested as an alternation in the shape of the response waveform from cycle to cycle, and also as spectral components at the half-fundamental ...

The purpose of the present study was to investigate the effect of red ginseng (Panax ginseng) extracts on the visual process in bullfrog's eye. The results obtained indicated that both dark-adapted and light-adapted ERG b-wave peak amplitude was increased with red ginseng treatment. Furthermore, the ERG sensitivity was elevated by ...

Propagation of light in a negative dispersion regime (antiparallel phase and group velocities) may be attributed to either fast light or a backward wave. We show that by applying causality, only one of these is valid for each scenario. A nanoplasmonic structure is shown to support both types of solution ...