Search Results
Results 51 - 100 of 1324
1 2 3 4 5 6 7 8 9 10 >
Harvey Michael - - 2012
Inhibitory interneurons play a critical role in the generation of gamma (20-50 Hz) oscillations, either by forming mutually inhibitory networks or as part of recurrent networks with pyramidal cells. A key property of fast spiking interneurons is their ability to generate brief spikes and high-frequency spike trains with little accommodation. ...
Vonderschen Katrin - - 2012
Birds and mammals exploit interaural time differences (ITDs) for sound localization. Subsequent to ITD detection by brainstem neurons, ITD processing continues in parallel midbrain and forebrain pathways. In the barn owl, both ITD detection and processing in the midbrain are specialized to extract ITDs independent of frequency, which amounts to ...
Fredrickson-Hemsing Lea - - 2012
In vitro, attachment to the overlying membrane was found to affect the resting position of the hair cell bundles of the bullfrog sacculus. To assess the effects of such a deflection on mechanically decoupled hair bundles, comparable offsets were imposed on decoupled spontaneously oscillating bundles. Strong modulation was observed in their ...
Neff Michael M - - 2012
In this issue of Developmental Cell, Cho et al. (2012) uncover the mechanisms linking the light-regulated trigger and hormone-mediated induction of seed germination in Arabidopsis. When phytochrome B is activated by red light, seed germination is promoted by epigenetic transcriptional activation of gibberellic acid biosynthetic enzymes via histone demethylation.
Lu Shena - - 2012
Two types of the attentional network, alerting and orienting, help organisms respond to environmental events for survival in the temporal and spatial dimensions, respectively. Here, we applied chromatic flicker beyond the critical fusion frequency to address whether awareness was necessary for activation of the two attentional networks. We found that ...
Rinaldi Jimena - - 2012
Light-oxygen-voltage (LOV) domains are blue light activated signaling modules present in a wide range of sensory proteins. Among them, the histidine kinases are the largest group in prokaryotes (LOV-HK). Light modulates the virulence of the pathogenic bacteria Brucella abortus through LOV-HK. One of the striking characteristic of Brucella LOV-HK is ...
van Nuenen Bart F L - - 2012
The dorsal premotor cortex (PMd) uses prior sensory information for motor preparation. Here, we used a conditioning-and-map approach in 11 healthy male humans (mean age 27 years) to further clarify the role of PMd in anticipatory motor control. We transiently disrupted neuronal processing in PMd, using either continuous theta burst ...
Kaliukhovich Dzmitry A - - 2012
Repetition of a visual stimulus reduces the firing rate of macaque inferior temporal (IT) neurons. The neural mechanisms underlying this adaptation or repetition suppression are still unclear. In particular, we do not know how the IT circuit is affected by stimulus repetition. To address this, we measured simultaneously local field ...
Alonso José Luis - - 2012
Cytoskeletal reorganization processes can be analyzed by studying the nanometer-scale spontaneous motion of beads bound to the cytoskeleton. The bead motion is determined by force fluctuations within the cytoskeletal network that originates from myosin motor activity and dynamic restructuring of cytoskeletal filaments. We investigated to what extend the spontaneous bead ...
Carney Laurel H - - 2012
Neural representations of speech at every level of the neuraxis have nonlinear features that are not described by spectrograms or linear filter-banks. In this study, recent computational models for populations of cells in the auditory periphery, brainstem, and midbrain were used to explore the implications of vowel features for neural ...
Chen Jessica - - 2012
A study of the humpback whale song in the Northwestern Hawaiian Islands (NWHI) and the Main Hawaiian Islands (MHI) during the 2009 season suggests that humpback whale song may be more variable than previously suggested. Data from five autonomous acoustic recorders deployed at locations in the NWHI and MHI were ...
Ketterling Jeffrey A - - 2012
Polymer-shelled ultrasound contrast agents (UCAs) can undergo a "compression only" behavior leading to shell rupture and nonlinear response of the released gas bubbles when excited below 10 MHz. This study investigated if polymer-shelled UCAs exhibited a similar behavior when excited at frequencies above 10 MHz. Four varieties of polylactide-shelled UCAs, ...
Chen Zhaocong - - 2012
It has been well documented that sensory responses to self-produced speech/vocalization are suppressed when compared to the sounds that are produced externally. Some recent studies, however, reported enhancement effect for active vocalization relative to passive listening. The present study was to address whether speaking-induced cortical activation can be modulated by ...
Ling Lin Shao - - 2012
The aim of this study was to verify the bactericidal effect and the damage of photodynamic inactivation (PDI) using methylene blue (MB) and tungsten-halogen lamp over Listeria monocytogenes via atomic force microscopy (AFM), absorption spectrophotometry, agarose gel electrophoresis, real-time PCR and SDS-PAGE. The obtained data indicated that the viability of ...
Chaudhary Vidhi - - 2012
The regulation of fungicidal and hydrolytic enzyme activity was investigated in a set of cyanobacterial strains belonging to the genus Anabaena (Anabaena laxa RPAN8, Anabaena iyengarii RPAN9, Anabaena variabilis RPAN59 and Anabaena oscillarioides RPAN69), with A. variabilis RPAN16 serving as negative control. Time course studies undertaken with cultures incubated under ...
Xiao Fu-Gui - - 2012
Nonradioactive dissipation of excitation energy is the most important photoprotective mechanism in plants. In high light, the trans-thylakoid ΔpH can activate the xanthophyll cycle and protonate the PsbS protein, which are important in regulating the process of non-photochemical quenching. Despite it has been proven that the ΔpH can directly switch ...
Peng Amy - - 2012
Synaptic vesicle exo- and endocytosis are usually driven by neuronal activity but can also occur spontaneously. The identity and differences between vesicles supporting evoked and spontaneous neurotransmission remain highly debated. Here we combined nanometer-resolution imaging with a transient motion analysis approach to examine the dynamics of individual synaptic vesicles in ...
Oudre L - - 2012
In this article we introduce a novel nonparametric classification technique based on the use of the Wasserstein distance. The proposed scheme is applied in a biomedical context for the analysis of recorded accelerometer data: the aim is to retrieve 3 types of periodic activities (walking, biking and running) from a ...
Dong Fan - - 2012
This research represents a highly enhanced visible light photocatalytic removal of 450ppb level of nitric oxide (NO) in air by utilizing flower-like hierarchical porous BiOI/BiOCl composites synthesized by a room temperature template free method for the first time. The facile synthesis method avoids high temperature treatment, use of organic precursors ...
Santos-Lozano Alejandro - - 2012
To analyze the intra- and inter-instrument reliability of the ActiGraph GT3X accelerometer using a vibration table on each orthogonal axis and at five frequencies of motion. Ten GT3X units were subjected to a specific vibration using a motorized vibration table along the vertical, horizontal right-left and horizontal front-back axis, and ...
Bozzola Angelo - - 2012
We theoretically investigate the light-trapping properties of one- and two-dimensional periodic patterns etched on the front surface of c-Si and a-Si thin film solar cells with a silver back reflector and an anti-reflection coating. For each active material and configuration, absorbance A and short-circuit current density Jsc are calculated by ...
Ebrahimi Mehdi - - 2012
The importance and applicability of ionic liquids (ILs) in biocatalysis have been well recognized. ILs have growing interest as new and highly efficient reaction mediums for biocatalytic reactions, but as a reaction milieu for firefly luciferase has not been tested. In this report, the effects of two tetramethylguanidine-based ionic liquids ...
Hou Yang - - 2012
A ternary Ag/AgBr/TiO2 nanotube array electrode with enhanced visible-light activity was synthesized by a two-step approach including electrochemical process of anodization and an in situ photo-assisted deposition strategy. The dramatically enhanced photoelectrocatalytic activity of the composite electrode was evaluated via the inactivation of Escherichia coli under visible light irradiation (λ ...
Kastelein Ronald A - - 2012
Mid-frequency and low-frequency sonar systems produce frequency-modulated sweeps which may affect harbor porpoises. To study the effect of sweeps on behavioral responses (specifically "startle" responses, which we define as sudden changes in swimming speed and/or direction), a harbor porpoise in a large pool was exposed to three pairs of sweeps: ...
Bergevin Christopher - - 2012
It has been proposed that OAEs be classified not on the basis of the stimuli used to evoke them, but on the mechanisms that produce them (Shera and Guinan, 1999). One branch of this taxonomy focuses on a coherent reflection model and explicitly describes interrelationships between spontaneous emissions (SOAEs) and ...
Warner Erica T ET Department of Epidemiology, Human Development and Health, Harvard School of Public Health, Boston, MA, - - 2012
To examine whether agreement between self-reported and accelerometer-measured physical activity varies by BMI category in a low-income black sample. Participants completed a questionnaire and wore an accelerometer for 4-6 days. Using one- and 10-minute bouts, accelerometers measured light, moderate, and vigorous physical activity time. Correlations varied by obesity (nonobese: one-minute ...
Hahn Petra - - 2013
The aim of this in vitro study was to evaluate the colour stability of bleaching after light activation with halogen unit, laser, LED unit or chemical activation up to 3 months after treatment. Four groups of teeth (n = 20) were bleached with Opalescence Xtra Boost (38% hydrogen peroxide) using four different methods: ...
Kashiwase Yoshiyuki - - 2012
Endogenous attention modulates the amplitude and phase coherence of steady-state visual-evoked potentials (SSVEPs). In efforts to decipher the neural mechanisms of attentional modulation, we compared the time course of attentional modulation of SSVEP amplitude (thought to reflect the magnitude of neural population activity) and phase coherence (thought to reflect neural ...
Howard Mary F MF Department of Linguistics, University of Maryland, College Park, Maryland 20742, USA. - - 2012
Speech elicits a phase-locked response in the auditory cortex that is dominated by theta (3-7 Hz) frequencies when observed via magnetoencephalography (MEG). This phase-locked response is potentially explained as new phase-locked activity superimposed on the ongoing theta oscillation or, alternatively, as phase-resetting of the ongoing oscillation. The conventional method used ...
Xing Chengfen - - 2012
The recent emergence of antibioticresistant micro-organisms has been a public-health problem world wide. A cationic polythiophene-porphyrin dyad (PTP) is shown to exhibit efficient lightactivated antifungal activity. The positive charges and amphiphilic structure of PTP encourage its adsorption to the fungus cell surface based on electrostatic and hydrophobic interactions. Higher efficiency ...
Thakral Preston P - - 2012
Aesthetic experience associated with viewing art has been hypothesized to depend on both low-level sensory processing and high-level conceptual processing. To test these hypotheses, we used functional MRI to evaluate the magnitude of activity in sensory motion processing region MT+ and in the prefrontal cortex while participants viewed van Gogh ...
Ellis Lee David - - 2012
The analysis of behavioural hyperactivity can provide insights into how perturbations in normal activity may be linked to the altered function of the nervous system and possibly the symptoms of disease. As a small vertebrate zebrafish have numerous experimental advantages that are making them a powerful model for these types ...
Lawson N C - - 2012
Recent studies confirmed that resin-modified glass ionomers (RMGIs) set on the basis of two competing mechanisms, an acid-base reaction and a light-activated resin polymerization. This study evaluated the effect of the setting mechanism on bond strength by measuring the shear bond strength of three RMGIs to dentin with and without ...
Müller Notger G - - 2012
Upon repetition, certain stimuli induce reduced neural responses (i.e., repetition suppression), whereas others evoke stronger signals (i.e., repetition enhancement). It has been hypothesized that stimulus properties (e.g., visibility) determine the direction of the repetition effect. Here, we show that the very same stimuli can induce both repetition suppression and enhancement, ...
Burgstaller Maria - - 2012
In many sensory systems adaptation acts as a gain control mechanism that optimizes sensory performance by trading increased sensitivity to low stimulus intensity for decreased sensitivity to high stimulus intensity. Adaptation of insect antennal olfactory receptor neurons (ORNs) has been studied for strong odour concentrations, either pulsed or constant. Here, ...
Doty Richard L - - 2012
Despite the fact that acute cases of multiple sclerosis (MS)-related pure-tone hearing loss have been reported in the literature, consensus is lacking as to the chronic influences of MS on pure-tone thresholds. Most studies examining such influences have been limited by small sample sizes, lack of statistical comparisons between patients ...
Wiertlewski Michael - - 2012
We describe a feedback-controlled active mechanical probe which can achieve a very low mechanical impedance, uniformly over a wide frequency range. The feedback produces a state of quasi-resonance which transforms the probe into a source of force used to excite an unknown load, resulting in a precise measurement of the ...
Hekler Eric B - - 2012
Recent research highlights the potential value of differentiating between categories of physical activity intensities as predictors of health and well-being. This study sought to assess reliability and concurrent validity of sedentary (ie, 1 METs), low-light (ie, >1 and ≤2 METs; eg, playing cards), high-light (ie, >2 and <3 METs; eg, ...
Li Ying - - 2012
The role of genetic inheritance in brain development has been well characterized, but little is known about the contributions of natural environmental stimuli, such as the effect of light-dark cycles, to brain development. In this study, we determined the role of light stimuli in neuronal cell migration to elucidate how ...
Shieh Dong-Lin - - 2012
Nitrogen-doped, porous rutile has been prepared by hydrothermal reaction of TiN in nitric acid, with the nitrogen atoms present in the interstitial sites and in the form of adsorbed nitrate ions. The N-rutile powder exhibits outstanding photocatalytic activity toward degradation of adsorbed methylene blue under visible light irradiation.
Razak Khaleel A - - 2012
Frequency modulated (FM) sweeps are common components of species-specific vocalizations. The intensity of FM sweeps can cover a wide range in the natural environment, but whether intensity affects neural selectivity for FM sweeps is unclear. Bats, such as the pallid bat, which use FM sweeps for echolocation, are suited to ...
Ó Maoiléidigh Dáibhid - - 2012
Hair cells in the auditory, vestibular, and lateral-line systems of vertebrates receive inputs through a remarkable variety of accessory structures that impose complex mechanical loads on the mechanoreceptive hair bundles. Although the physiological and morphological properties of the hair bundles in each organ are specialized for detecting the relevant inputs, ...
Domysławska J - - 2012
Absolute positions of several oxygen B-band lines were measured with the Pound-Drever-Hall-locked frequency-stabilized cavity ring-down spectrometer. The frequency axis of spectra was linked to the optical frequency comb. Achieved uncertainties of line positions are between 0.9 and 2.9 MHz. Self-pressure shifts coefficients are also reported.
Willcockson Michael A - - 2012
INTRODUCTION: Although both humans and quadrupeds frequently coordinate breathing and limb movement during running, early studies in humans focused on how increased breathing flexibility in humans allowed for relaxed or even transient coordination during locomotion. This difference was used to explain why quadrupeds had an optimal running speed while humans ...
Le Khai Q - - 2012
We theoretically investigate and compare the influence of square silver gratings and one-dimensional photonic crystal (1D PC) based nanostructures on the light absorption of organic solar cells with a thin active layer. We show that, by integrating the grating inside the active layer, excited localized surface plasmon modes may cause ...
Price Nicholas S C - - 2012
Perception depends on the relative activity of populations of sensory neurons with a range of tunings and response gains. Each neuron's tuning and gain are malleable and can be modified by sustained exposure to an adapting stimulus. Here, we used a combination of human psychophysical testing and models of neuronal ...
Berman Jeffrey I JI Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, - - 2012
There is an increasing interest in examining cross-frequency coupling (CFC) between groups of oscillating neurons. Most CFC studies examine how the phase of lower-frequency brain activity modulates the amplitude of higher-frequency brain activity. This study focuses on the signal filtering that is required to isolate the higher-frequency neuronal activity which ...
Luvizotto Andre - - 2012
It has been proposed that the dense excitatory local connectivity of the neo-cortex plays a specific role in the transformation of spatial stimulus information into a temporal representation or a temporal population code (TPC). TPC provides for a rapid, robust, and high-capacity encoding of salient stimulus features with respect to ...
Schaefer Andreas T AT Department of Neuroscience, Physiology and Pharmacology University College London, - - 2012
Electrophysiological and population imaging data in rodents show that olfactory bulb (OB) activity is profoundly modulated by the odor sampling process while behavioral experiments indicate that odor discrimination can occur within a single sniff. This paper addresses the question of whether action potential (AP) latencies occurring across the mitral and ...
Vanhelst Jérémy - - 2012
Most accelerometers are worn around the waist (hip or lower back) to assess habitual physical activity. Wrist-worn accelerometers may be an alternative to the waist-worn monitors and may improve compliance in studies with prolonged wear. The aim of this study was to validate the Vivago® Wrist-Worn Accelerometer at various intensities ...
1 2 3 4 5 6 7 8 9 10 >