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Results 351 - 400 of 950
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Wang Hai-Hua - - 2009
We experimentally demonstrate the slowing and storage of double light pulses in a Pr(3+):Y(2)SiO(5) crystal using a multilevel-tripod scheme. Owing to double dark-state polaritons of the tripod-type system, two signal pulses can be simultaneously slowed. Also, we realize the simultaneous storage (and retrieval) of double light pulses by switching off ...
Colleye O - - 2009
Fourteen individuals of the skunk clownfish Amphiprion akallopisos of different sizes and of different sexual status (non-breeder, male or female) were analysed for four acoustic features. Dominant frequency and pulse duration were highly correlated with standard length (r = 0.97), and were not related to sex. Both the dominant frequency ...
Ma Seong-Min - - 2009
Electromagnetically-induced transparency (EIT) is observed and analyzed for the group velocity of a femtosecond light pulse interacting with GaAs/AlGaAs multiple quantum wells (MQWs) in a transient regime. The calculated slowdown factor of the group velocity inside the medium due to the dynamic refractive index change is approximately 2.10 x 10(3). ...
Franklin Clifford - - 2009
OBJECTIVE: American Speech-Language-Hearing Association (ASHA) guidelines allow pulsed and warbled tones in measuring audiometric thresholds and include test frequencies of 3000 and 6000 Hz. However, no research has examined the relationship between thresholds obtained with these stimuli at these frequencies. This study investigated the relationship between thresholds obtained with pulsed, ...
Kawabe Takahiro T Kyushu University, Fukuoka 812-8581, Japan. - - 2009
When sequential visual flashes are accompanied by a lower number of sequential auditory pulses, the perceived number of visual flashes is lower than the actual number, an illusion termed 'flash fusion'. We examined whether temporal capture of flashes by pulses underlay flash fusion. One of the visual flashes was given ...
van Hoesel Richard J M RJ The Hearing CRC, 550 Swanston St., Carlton, Victoria, 3053, Australia. - - 2009
Electrical interaural time delay (ITD) discrimination was measured using 300-ms bursts applied to binaural pitch matched electrodes at basal, mid, and apical locations in each ear. Six bilateral implant users, who had previously shown good ITD sensitivity at a pulse rate of 100 pulses per second (pps), were assessed. Thresholds ...
Swerdlow Neal R - - 2009
Startle is inhibited when a startling stimulus follows 30-300 ms after a weak prepulse. Prepulse inhibition (PPI) is an operational measure of sensorimotor gating and is deficient in several neuropsychiatric disorders. Previous reports argue both for and against a learned component to the inhibitory effects of prepulses, but this issue ...
Majdak Piotr - - 2009
The effects of center frequency and pulse rate on the sensitivity to ongoing envelope interaural time differences (ITDs) were investigated using bandpass-filtered pulse trains. Three center frequencies (4.6, 6.5, and 9.2 kHz) were tested with bandwidths scaled to stimulate an approximately constant range on the basilar membrane. The pulse rate ...
Cohen Ethan D - - 2009
We examined how stimulation of the local retina by high-level current pulse trains affected the light-evoked responses of the retinal ganglion cells. The spikes of retinal ganglion cell axons were recorded extracellularly using an in vitro eyecup preparation of the rabbit retina. Epiretinal electrical stimulation was delivered via a 500 ...
Jensen Ralph J - - 2009
We and other research groups are designing an electronic retinal prosthesis to provide vision for patients who are blind due to photoreceptor degeneration. In this study, we examined the effect of stimulus waveform on the amount of current needed to activate retinal ganglion cells (RGCs) when the retinal neural network ...
Berón de Astrada Martín - - 2009
In crustaceans, sustaining (SN) and dimming (DN) neurons are readily identified by their distinct responses to a light pulse. However, morphological identification and electrophysiological characterization of these neurons has been achieved only in the crayfish. This study provides a description of SNs and DNs in a second crustacean species, the ...
Moore Brian C J BC Department of Experimental Psychology, University of Cambridge, Downing Street, Cambridge CB2 3EB, England. - - 2009
The audibility of partials was measured for complex tones with partials uniformly spaced on an ERB(N)-number scale. On each trial, subjects heard a sinusoidal "probe" followed by a complex tone. The probe was mistuned downwards or upwards (at random) by 3% or 4.5% from the frequency of one randomly selected ...
Wiatrek Andrzej - - 2009
This article describes a new approach to cancel the pulse broadening in a cascaded slow-light system. With the help of a simple experimental setup a method with significant potential to achieve a high pulse delay at almost zero pulse broadening is shown. Since the pulse reshaping is done inside a ...
Zhang Baile - - 2009
We present a full-wave analysis method on the transmission of a Gaussian light pulse through a spherical invisibility cloak with causal dispersions. The spatial energy distribution of the Gaussian light pulse is distorted after the transmission. A volcano-shaped spatial time-delay distribution of the transmitted light pulse is demonstrated as a ...
Ryu Sang Baek - - 2009
For successful restoration of visual function by retinal implant, a method for electrical stimulation should be devised so that the evoked activities of retinal ganglion cells (RGCs) should convey sufficient information on visual input. By observing RGC activities under different stimulation constraints, it may be possible to determine optimal pulse ...
Castellote Manuel - - 2009
Seafloor recorders were deployed along the Spanish Mediterranean coast during 2006-2009 to further contribute to the little knowledge regarding Mediterranean fin whale (Balaenoptera physalus) movement patterns. Typical long patterned sequences of 20-Hz pulses were identified in different periods. Detection results suggest that at least part of the Mediterranean fin whales ...
Supin Alexander Ya - - 2009
Auditory evoked potentials (AEPs) were recorded during echolocation in a false killer whale Pseudorca crassidens. An electronically synthesized and played-back ("phantom") echo was used. Each electronic echo was triggered by an emitted biosonar pulse. The echo had a spectrum similar to that of the emitted biosonar clicks, and its intensity ...
Flecke Christian - - 2009
In moths octopamine improved pheromone-dependent mate search time dependently. In the nocturnal hawkmoth Manduca sexta long-term tip recordings of trichoid sensilla were performed to investigate whether biogenic amines modulate pheromone transduction time dependently. At three Zeitgebertimes octopamine, tyramine and the octopamine antagonist epinastine were applied during non-adapting pheromone-stimulation. At ZT ...
Gonzalez-Herraez Miguel - - 2009
The dispersion experienced by a signal in a slow light system leads to a significant pulse broadening and sets a limit to the maximum delay actually achievable by the system. To overcome this limitation, a substantial research effort is currently being carried out, and successful strategies to reduce distortion in ...
Du Huini H Department of Biomedical Engineering, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA. - - 2009
We investigate a novel detector using a lutetium oxyorthosilicate (LSO) scintillator and YGG (yttrium-aluminum-gallium oxide:cerium, Y(3)(Al,Ga)(5)O(12):Ce) phosphor to construct a detector with continuous depth-of-interaction (DOI) information. The far end of the LSO scintillator is coated with a thin layer of YGG phosphor powder which absorbs some fraction of the LSO ...
Lapshin D N - - 2009
The auditory system of noctuoid moths capable to respond to ultrasounds has long been a model for anti-predator studies in neuroethology. Many moths avoid hunting bats by listening for their echolocation calls and taking evasive manoeuvres to escape predation. Besides these flight defences, certain tiger moths (Arctiidae) emit high-frequency clicks ...
Fortune Brad - - 2009
The purpose of the present study was to compare standard multifocal visual evoked potential (mfVEP) pattern-reversal responses with those produced by pattern-onset, pattern-offset, and pulsed pattern stimuli. mfVEP recordings were obtained from five normal subjects using VERIS and a 4-electrode array. The standard reversal stimulus had 2(15) m-sequence steps (7.5-min ...
Verfuss Ursula K - - 2009
Synchronized video and high-frequency audio recordings of two trained harbour porpoises searching for and capturing live fish were used to study swimming and echolocation behaviour. One animal repeated the tasks blindfolded. A splash generated by the fish being thrown into the pool or - in controls - by a boat ...
Brondon Philip - - 2009
BACKGROUND AND OBJECTIVES: Skin pigmentation can adversely affect phototherapy outcomes. Delivering pulsed light has been suggested as a means of enhancing efficacy. Suitable pulse frequencies remain indeterminate, often being selected empirically. This study was undertaken to determine whether pulsed light delivery mitigates the filtering effect of melanin pigment on photomodulation ...
Jafarzadeh Hamid - - 2009
Tests relying on the passage of light through a tooth have been considered to be a suitable means of assessing vascularity and pulp vitality. Pulse oximetry is an effective, objective oxygen saturation monitoring technique broadly used in medicine for recording blood oxygen saturation levels. It can also be used in ...
van der Heide Esther M - - 2009
: Changing the amplitude of single rectangular pulse stimuli (SP) has the disadvantage of recruiting tactile and nociceptive fibers in a changing, unknown proportion. Keeping the amplitude constant, but applying a varying number of pulses in a train is another way of stimulus variation, keeping the proportion constant. So, pulse ...
Manolea H H Department of Morphology and Semiology of Stomatognate System, Dental Materials and Dental Prosthesis Technology , Faculty of Dentistry, UMF - - 2009
The mechanical properties of the light-cured composite resins are related to the material composition, but also vary according to the light-source characteristics used for polymerization. In this study we followed the compressive strength variation for a light-cured composite resin according to the time of exposure to the curing light. With ...
Cannesson Maxime - - 2009
Conventional pulse oximetry uses two wavelengths of light (red and infrared) transmitted through a finger and a photodetector to analyze arterial hemoglobin oxygen saturation and pulse rate. Recent advances in pulse oximetry include: extended analysis of the photo plethysmographic waveform; use of multiple wavelengths of light to quantify methemoglobin, carboxyhemoglobin ...
Tsai D D Graduate School of Biomedical Engineering, University of New South Wales, Sydney, - - 2009
Recent advances in the design and implementation of vision prostheses have made these devices a promising therapeutic option for restoring sight to blind patients in the near future. The success of vision prostheses in providing clinically useful vision, however, depends critically on our understanding of the retinal neural mechanisms evoked ...
Baba Toshihiko - - 2009
Slow light with a markedly low group velocity is a promising solution for optical buffering and advanced time-domain optical signal processing. It is also anticipated to enhance linear and nonlinear effects and so miniaturize functional photonic devices because slow light compresses optical energy in space. Photonic crystal waveguide devices generate ...
Jeng Fuh-Cherng - - 2009
The electrically evoked compound action potential (ECAP) of the auditory nerve in response to amplitude-modulated pulse trains varies over time, but the response amplitudes are not linearly proportional to the level of stimulus pulses. At least two mechanisms could contribute to the deviations of the ECAP response pattern from that ...
Tsuyama Michito - - 2009
During steady-state photosynthesis in low-light, 830-nm absorption (A(830)) by leaves was close to that in darkness in Arabidopsis, indicating that the primary donor P700 in the reaction center of photosystem I (PSI) was in reduced form. However, P700 was not fully oxidized by a saturating light pulse, suggesting the presence ...
Wilson Maria - - 2008
Most fish cannot hear frequencies above 3 kHz, but a few species belonging to the subfamily Alosinae (family Clupeidae) can detect intense ultrasound. The response of adult specimens of the European allis shad (Alosa alosa) to sinusoidal ultrasonic pulses at 70 and 120 kHz is tested. The fish showed an ...
Badiey Mohsen - - 2008
Fluctuations of the sound pulse phase front propagating approximately perpendicular to the direction of motion of a train of intensive internal waves in the experiment Shallow Water 2006 (SW06) are studied. Acoustic data received by a horizontalvertical line array (WHOI-Shark array) during 3 h are analyzed. Low-frequency modulated signals with ...
Supin Alexander - - 2008
In a false killer whale Pseudorca crassidens, auditory evoked potentials (AEPs) were recorded in conditions of echolocation using both real targets and electronically synthesized and played-back (phantom) echoes. The electronic echoes were triggered by emitted sonar pulses, their spectra were similar to that of the emitted sonar clicks of the ...
Bee Mark A - - 2008
'Sequential integration' represents a form of auditory grouping in which temporally separated sounds produced by the same source are perceptually bound together over time into a coherent 'auditory stream'. In humans, sequential integration plays important roles in music and speech perception. In this study of the grey treefrog (Hyla chrysoscelis), ...
Gerhardt H Carl HC Division of Biological Sciences, University of Missouri, Columbia, MO 6521, USA. - - 2008
The two main spectral components of the advertisement calls of two species of North American gray treefrogs (Hyla chrysoscelis and H. versicolor) overlap broadly in frequency, and the frequency of each component matches the sensitivity of one of the two different auditory inner ear organs. The calls of the two ...
Hiryu Shizuko - - 2008
Echolocation pulses emitted by wild Pipistrellus abramus were investigated while foraging for insects in the field. Similar to other European pipistrelles, the frequency structure during foraging varied. During the search phase, the bats emitted long shallow frequency-modulated pulses 9-11 ms in duration, whereas the maximum pulse duration of the bats ...
Schwartz Joshua J - - 2008
Male gray treefrogs call to attract females under challenging acoustic conditions. At higher chorus densities, there is considerable background noise and a good chance that a male's calls will often be overlapped by calls of other individuals. Call overlap may reduce the probability of mating because females prefer calls with ...
Supin Alexander Ya - - 2008
In a false killer whale Pseudorca crassidens, echo perception thresholds were measured using a go/no-go psychophysical paradigm and one-up-one-down staircase procedure. Computer controlled echoes were electronically synthesized pulses that were played back through a transducer and triggered by whale emitted biosonar pulses. The echo amplitudes were proportional to biosonar pulse ...
Goulielmakis E - - 2008
Self-channeling of few-cycle laser pulses in helium at high pressure generates coherent light supercontinua spanning the range of 270-1000 nm, with the highest efficiency demonstrated to date. Our results open the door to the synthesis of powerful light waveforms shaped within the carrier field oscillation cycle and hold promise for ...
Rivers Trevor J - - 2008
In the western Caribbean Sea, about an hour after the sun sets, a complex and ritualized light show of precise, vertically placed luminescent pulses erupts over shallow grassbeds. These are among the most complex displays known in marine systems. Displays consist of repeated trains of secreted bioluminescent pulses in a ...
Smotherman Michael M Department of Biology, Texas A&M University, College Station, Texas 77843-3258, - - 2008
Doppler-shift compensation behavior (DSC) is a highly specialized vocal response displayed by bats that emit pulses with a prominent constant frequency (CF) component and adjust the frequency of their CF component to compensate for flight-speed induced Doppler shifts in the frequency of the returning echoes. DSC has only been observed ...
Savolainen Janne - - 2008
Adaptive femtosecond pulse shaping in an evolutionary learning loop is applied to a bioinspired dyad molecule that closely mimics the early-time photophysics of the light-harvesting complex 2 (LH2) photosynthetic antenna complex. Control over the branching ratio between the two competing pathways for energy flow, internal conversion (IC) and energy transfer ...
Ahmed Zaghloul - - 2008
The influence of a pulsed magnetic field (PMF) on hippocampal evoked potentials has been investigated in vitro. The exposure to PMF (0.16 Hz, 15 mT) applied for 30 min amplified the population spike and the slope of EPSP recorded from stratum pyramidale and stratum radiatum respectively. This amplification was additive ...
Kastelein Ronald A - - 2008
Two harbor porpoises in a floating pen were subjected to five pure tone underwater signals of 70 or 120 kHz with different signal durations, amplitudes and duty cycles (% of time sound is produced). Some signals were continuous, others were intermittent (duty cycles varied between 8% and 100%). The effect ...
Riquimaroux Hiroshi - - 2008
It has been reported that the bats communicate with conspecifics by various types of vocalizations, which are different from echolocation pulses. However, we have found pulses used for communication, which were emitted when a bat walked to another individual, appeared to be very similar to those for echolocation. Data have ...
Simard Peter - - 2008
Dolphin vocalizations are generally categorized as tonal whistles or pulsed clicks. Pulsed signals in dolphins are usually associated with echolocation, however an increasing number of species are found to produce burst pulse signals which may be used for communication. Groups of white-beaked dolphins (Lagenorhynchus albirostris) were recorded from a 4.2 ...
Carlyon Robert P - - 2008
Modern cochlear implants (CIs) convey fundamental frequency (F0) information using a purely temporal code. However, temporal pitch processing - as measured by the discrimination of the changes in the rate of a pulse train applied to a single electrode - is often worse than in normal hearing (NH) at low ...
Luo Ercang - - 2008
In this talk, recent progress on thermoacoustic heat engines and refrigerators developed at the Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS), is covered, which mainly includes three aspects: (i) Energy-focused thermoacoustic-Stirling heat engines (EF-TASHE) by using tapered resonators are highlighted for both low-frequency (50Hz) and ...
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