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Results 251 - 300 of 950
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Treier Matthias - - 2012
We report on the formation of photoconductive self-assembled fibres by solvent induced precipitation of a HBC-PMI donor-acceptor dyad. Kelvin Probe Force Microscopy revealed that upon illumination with white light the surface potential of the fibres shifted to negative values due to a build-up of negative charge. When integrated in a ...
Cao Dingcai D Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, 1905 West Taylor Street, Room 149, Chicago, Illinois 60615, USA. - - 2012
To test whether a retinal or cortical mechanism sums contributions from two adapting fields to chromatic discrimination, L/M discrimination was measured with a test annulus surrounded by an inner circular field and an outer rectangular field. A retinal summation mechanism predicted that the discrimination pattern would not change with a ...
Nikiforakis Nikos - - 2012
The rarity of altruistic punishment in small-scale societies should not be interpreted as evidence that altruistic punishment is not an important determinant of cooperation in general. While it is essential to collect field data on altruistic punishment, this kind of data has limitations. Laboratory experiments can help shed light on ...
Bamber C - - 2012
We present a method for measuring the transverse electric field profile of a beam of light which allows for direct phase retrieval. The measured values correspond, within a normalization constant, to the real and imaginary parts of the electric field in a plane normal to the direction of propagation. This ...
Jin Yu - - 2012
The variation of polarization distribution of reflected beam at specular interface and far field caused by spin separation has been studied. Due to the diffraction effect, we find a distinct difference of light polarization at the two regions. The variation of polarization distribution of reflected light provides a new method ...
Hsu Ben B Y - - 2012
The split-gate light emitting field effect transistors (SG-LEFETs) demonstrate a new strategy for ambipolar LEFETs to achieve high brightness and efficiency simultaneously. The SG architecture forces largest quantity of opposite charges on Gate 1 and Gate 2 area to meet in the center of the channel. By actively and independently ...
Luo Yu - - 2012
Metallic structures with sharp corners harvest the energy of incident light through plasmonic resonances, concentrating it in the corners and greatly increasing the local energy density. Despite its wide array of applications, this effect is normally strongly dependent on how sharp the corners are, presenting problems for fabrication. In this ...
Keating Brian B Department of Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii, USA. - - 2012
Subject motion during brain magnetic resonance spectroscopy acquisitions generally reduces the magnetic field (B₀) homogeneity across the volume of interest or voxel. This is the case even if prospective motion correction ensures that the voxel follows the head. We introduce a novel method for rapidly mapping linear variations in B₀ ...
Sleemi Aamar - - 2012
Abstract Background: Bright-light treatment is a safe and effective treatment for the management of winter seasonal affective disorder (SAD). In a recent study, we found that the relative duration of reading was positively associated with likelihood of remission after six weeks of light treatment. Methods: Two technicians measured the illuminance ...
Dias Maria P - - 2012
Long-distance migrants have developed diverse strategies to deal with the challenges imposed by their annual journeys. These are relatively well studied in some avian groups, such as passerines, shorebirds and raptors. In contrast, few studies have addressed the migratory behaviour of pelagic birds in the light of current theories of ...
Zhang Dian - - 2012
[This corrects the article on p. e45792 in vol. 7.].
Wiltschko Roswitha - - 2012
Animals can use the direction of the magnetic field as a compass and the intensity of the magnetic field as a component of the navigational 'map'. Two fundamentally different mechanisms of magnetoreception have been discussed: (1) light-dependent reactions in specialized photopigments lead to radical pairs, with the ratio singlet/ triplet ...
Dypvik Eivind E Red Sea Research Center, 4700 King Abdullah University of Science and Technology, Thuwal, 23955-6900 Saudi - - 2012
The seasonal variations in glacier lanternfish (Benthosema glaciale) vertical distribution and diel vertical migration (DVM) were studied by use of a bottom-mounted upward-facing 38 kHz echo sounder deployed at 392 m depth and cabled to shore in Masfjorden (~60°52'N, ~5°24'E), Norway. Acoustic data from July 2007-October 2008 were analyzed, and scattering layers ...
Lemoult Fabrice - - 2012
Breaking the diffraction barrier in the visible part of the electromagnetic spectrum is of fundamental importance. Far-field subwavelength focusing of light could, for instance, drastically broaden the possibilities available in nanolithography, light-matter interactions and sensing at the nanoscale. Similarly, imaging with a nanometric resolution could result in incredible breakthroughs in ...
Njeh Christopher F - - 2012
The radiation field on most megavoltage radiation therapy units are shown by a light field projected through the collimator by a light source mounted inside the collimator. The light field is traditionally used for patient alignment. Hence it is imperative that the light field is congruent with the radiation field. ...
Kroes Thomas - - 2012
The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR) by integrating a number of ...
Fortenbaugh Francesca C - - 2012
Previous studies of localization of stationary targets in the peripheral visual field have found either underestimations (foveal biases) or overestimations (peripheral biases) of target eccentricity. In the present study, we help resolve this inconsistency by demonstrating the influence of visual boundaries on the type of localization bias. Using a Goldmann ...
Norris Barnaby R M - - 2012
An intermediate-mass star ends its life by ejecting the bulk of its envelope in a slow, dense wind. Stellar pulsations are thought to elevate gas to an altitude cool enough for the condensation of dust, which is then accelerated by radiation pressure, entraining the gas and driving the wind. Explaining ...
Palmisano Stephen - - 2012
Previous research has shown that vection can be enhanced by adding horizontal simulated viewpoint oscillation to radial flow. Adding a horizontally oscillating fixation target to purely radial flow induces a superficially similar illusion of self-motion, where the observer's perceived heading oscillates left and right as their eyes pursue the moving ...
Suzuki Hiroyuki H Graduate School of Engineering, Chiba University, Chiba, Japan. - - 2012
Recently, it has been reported that finger motions could be recognized from the forearm signal detected by accelerometers. However, accelerometers are sensitive to vibration or unintended motions, which could cause large noise when classifying different hand motions. This is why our research group wanted to explore the usability of other ...
Yu Chengjiao - - 2012
Friction characteristics with respect to surface topographic orientation were investigated using surfaces of different materials and fabricated with grooves of different scales. Scratching friction tests were conducted using a nano-indentation-scratching system with the tip motion parallel or perpendicular to the groove orientation. Similar friction anisotropy trends were observed for all ...
Fiedler P P Ilmenau University of Technology, Germany. - - 2012
The acquisition of physiological parameters using textile and textile-integrated sensors has become an important alternative for mobile and long-term monitoring. We analyzed to different commercially available electrically conductive textiles concerning their applicability for textile-based impedance pneumography. We immersed the textiles to four corroding solutions and observed no considerable changes in ...
Frings Stephan - - 2012
In the course of evolution, the strong and unremitting selective pressure on sensory performance has driven the acuity of sensory organs to its physical limits. As a consequence, the study of primary sensory processes illustrates impressively how far a physiological function can be improved, if the survival of a species ...
Yan Qingwen - - 2012
In this paper we present recent work on the design, fabrication by silicon micromachining, and packaging of a new gyroscope for stabilizing the autopilot of rotating aircraft. It operates based on oscillation of the silicon pendulum between two torsion girders for detecting the Coriolis force. The oscillation of the pendulum ...
Zucker Robert Martin - - 2012
Scientific evaluation of potential environmental hazards resulting from man-made nanomaterials has been hampered by the inability to optimally detect cell-associated nanoparticles. We have successfully imaged TiO(2) nanoparticles in ARPE-19 cells using different light microscope modalities commonly available to investigators including fluorescence, dark field, phase, interference, and confocal. In this report, ...
Pospisil Eric R ER CARIS Lab, Department of Mechanical Engineering, University of British Columbia, Vancouver, BC V6T 1Z4 Canada. - - 2012
We present a validation study for the effectiveness of an additional ankle-tilt platform to enhance somatosensory ankle feedback available to subjects actuating a 6-axis robotic balance simulator platform. To address this need, we have developed and integrated a device to permit independent manipulation of ankle rotation while the whole-body is ...
Shepherd Robert F - - 2011
This manuscript describes a unique class of locomotive robot: A soft robot, composed exclusively of soft materials (elastomeric polymers), which is inspired by animals (e.g., squid, starfish, worms) that do not have hard internal skeletons. Soft lithography was used to fabricate a pneumatically actuated robot capable of sophisticated locomotion (e.g., ...
Macrum Elisabeth - - 2011
CONTEXT: Limitations in gastrocnemius/soleus flexibility, which restricts ankle dorsiflexion during dynamic tasks, have been reported in individuals with patellofemoral pain (PFP) and are theorized to play a role in the development of PFP. OBJECTIVE: To determine the effect of restricted ankle dorsiflexion range of motion (ROM) on lower extremity kinematics ...
Demura Tomohiro - - 2012
This study aimed to examine the effect of shoes with a rounded soft sole (Stretch Walker: SW) on gait. Fifteen healthy male (mean age: 23.2) walked under three conditions (SW, Flat-bottomed Shoe: FS, Barefoot: BF). Including walking speed, stance time, step length were selected as temporal-spatial parameters. The angle of ...
Dypvik Eivind E Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, 23955-6900 Saudi Arabia ; Department of Biology, University of Oslo, P.O. Box 1066, Blindern, 0316 Oslo, - - 2012
A bottom-mounted upward-facing 38-kHz echo sounder was deployed at ~400 m and cabled to shore in Masfjorden (~60(°)52'N, ~5(°)24'E), Norway. The scattering layers seen during autumn (September-October) 2008 were identified by trawling. Glacier lanternfish (Benthosema glaciale) were mainly distributed below ~200 m and displayed three different diel behavioral strategies: normal diel vertical ...
Marlow Phillip - - 2011
One function of the visual system is to combine the different views of the two eyes so that each object appears in a single direction. Using pairs of isolated dots, previous studies have found that binocular fusion gives way to diplopia if the disparity gradient between the dots is steep. ...
Reichard Dustin G - - 2011
Abstract Research on the function of acoustic signals has focused on high-amplitude long-range songs (LRS) and largely ignored low-amplitude songs produced by many species during close-proximity, conspecific interactions. Low-amplitude songs can be structurally identical to LRS (soft LRS), or they can be widely divergent, sharing few spectral and temporal attributes ...
Whissell Cynthia - - 2011
This research was designed to test the hypothesis that Milton's poem Paradise Lost is meaningfully patterned with respect to sound. Thirty-six segments from 12 Books of Paradise Lost were scored (Whissell, 2000) in terms of their proportional use of Pleasant, Cheerful, Active, Nasty, Unpleasant, Sad, Passive, and Soft sounds. Paradise ...
Jie Tan - - 2011
In computer animation, the proportional-derivative (PD) controller is a common technique for tracking characters' motion. A new formulation of the PD controller-stable PD (SPD)-allows arbitrarily high gains, even at large time steps. The key is to determine joint forces and torques while taking into account the character's positions and velocities ...
Ziegler Lucía - - 2011
The structure of the environment surrounding signal emission produces different patterns of degradation and attenuation. The expected adjustment of calls to ensure signal transmission in an environment was formalized in the acoustic adaptation hypothesis. Within this framework, most studies considered anuran calls as fixed attributes determined by local adaptations. However, ...
Weynberg Karen D - - 2011
Ostreococcus tauri, a unicellular marine green alga, is the smallest known free-living eukaryote and is ubiquitous in the surface oceans. The ecological success of this organism has been attributed to distinct low- and high-light-adapted ecotypes existing in different niches at a range of depths in the ocean. Viruses have already ...
Redi Carloalberto - - 2011
The first part of the book (six chapters) is devoted to some selected applications of bright-field microscopy while the second part (eight chapters) to some fluorescence microscopy studies. Both animal and plant biology investigations are presented covering multiple fields like immunology, cell signaling, cancer biology and, surprisingly to me, ecology. ...
Munar Enric - - 2011
Improvements in neuroimaging methods have afforded significant advances in our knowledge of the cognitive and neural foundations of aesthetic appreciation. We used magnetoencephalography (MEG) to register brain activity while participants decided about the beauty of visual stimuli. The data were analyzed with event-related field (ERF) and Time-Frequency (TF) procedures. ERFs ...
Soltes Barbara - - 2010
Intense Pulsed Light (IPL) is an FDA-approved photo therapy for the treatment of a variety of conditions such as acne and hirsutism. It utilizes the principle of selective photothermolysis. Photothermolysis allows a specific wavelength to be delivered to a chromophore of a designated tissue while leaving the surrounding tissue unaffected. ...
Long Chloe V - - 2010
Bat mortality resulting from actual or near-collision with operational wind turbine rotors is a phenomenon that is widespread but not well understood. Because bats rely on information contained in high-frequency echoes to determine the nature and movement of a target, it is important to consider how ultrasonic pulses similar to ...
Koblitz Jens C - - 2010
Recordings of the echolocation signals of landing big brown bats with a two-dimensional 16-microphone array revealed that the source level reduction of 7 dB per halving of distance is superimposed by a variation of up to 12 dB within single call groups emitted during the approach. This variation correlates with ...
Li J - - 2010
The major objective of the study was to evaluate the enhanced germicidal effects of low-frequency pulsed ultraviolet A (UVA)-light-emitting diode (LED) on biofilms. The germicidal effects of UVA-LED irradiation (365 nm, 0·28 mW cm(-2) , in pulsed or continuous mode) on Candida albicans or Escherichia coli biofilms were evaluated by ...
Genty Goëry - - 2010
We analyze the coherence properties of supercontinuum generated in photonic crystal fibers by applying the second-order coherence theory of nonstationary light. Using an ensemble of simulated realizations, we construct two-frequency cross-spectral density and two-time mutual coherence functions. This allows us to introduce measures of temporal and spectral coherence. We show ...
Bae In-Ho - - 2010
We report an experimental demonstration of slow and superluminal propagation of pseudo-thermal (chaotic) light in the Λ-type system of the 5S(1/2)-5P(1/2) transition of (87)Rb atom. The slowed propagation of pulsed pseudo-thermal light was demonstrated in an electromagnetically-induced transparency medium while the superluminal propagation was demonstrated with the enhanced absorption scheme ...
Davidovics Natan S NS Departments of Otolaryngology/Head and Neck Surgery and Biomedical Engineering, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA. - - 2011
An implantable prosthesis that stimulates vestibular nerve branches to restore sensation of head rotation and vision-stabilizing reflexes could benefit individuals disabled by bilateral loss of vestibular (inner ear balance) function. We developed a prosthesis that partly restores normal function in animals by delivering pulse frequency modulated (PFM) biphasic current pulses ...
Jelinek Herbert F - - 2010
OBJECTIVES: To investigate the effect that electric pulse frequency has on the perceived magnitude of sensation and to quantify the relationship between electric pulse frequency and perceived magnitude of sensation during low-intensity electrocutaneous stimulation. DESIGN: A repeated-measures research design was applied to evaluate the effect of electric pulse frequency on ...
Mettler Joni A - - 2010
Muscle force potentiation affects force output during electrical stimulation. Few studies have examined stimulation train parameters that influence potentiation such as pulse number, stimulation frequency, train duration, and force-time integral and peak force produced during the train. Pulse-matched trains (100 pulses) at 7.5, 15, 25, 30, 50, and 100 Hz, and ...
Palgan I - - 2011
High Intensity Light Pulses (HILP) represent an emerging processing technology which uses short (100-400 μs) light pulses (200-1100 nm) for product decontamination. In this study, model and real foods of differing transparencies (maximum recovery diluent (MRD), apple and orange juices and milk) were exposed to HILP in a batch system ...
Lo Hsiang-Yu - - 2010
We report on an experimental demonstration of applying the beat-note interferometer to simultaneously measure the phase and amplitude variations of light pulses after propagating through an electromagnetically induced transparency medium at femtowatt-light levels. Furthermore, we observe that the measured phase noise approaches the shot-noise level arising from the fluctuations of ...
Saito Yuji - - 2010
We propose a simple technique of stopping light pulses using a slow-light device based on photonic crystal coupled waveguide (PCCW). Dynamically tuning the material index chirp in the PCCW adiabatically transforms slow-light pulses into stopped ones. We demonstrate this in finite-difference time-domain simulation assuming ideal and actual tuning of the ...
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