Search Results
Results 101 - 150 of 883
1 2 3 4 5 6 7 8 9 10 >
Hanada Mitsuhiko - - 2012
How motion onset asynchrony (MOA) alters the effects of stimulus size on reaction time (RT) for direction discrimination of a drifting grating was examined. MOA is a delay from the stimulus onset to the onset of motion. Without MOA, RTs were found to increase as the stimulus size was increased ...
Falk Marianne - - 2012
Real-time dynamic multileaf collimator (MLC) tracking for management of intrafraction tumor motion can be challenging for highly modulated beams, as the leaves need to travel far to adjust for target motion perpendicular to the leaf travel direction. The plan modulation can be reduced by using a leaf position constraint (LPC) ...
Perrin Douglas P - - 2012
We describe a method to increase the frame rate for 3-dimensional ultrasound sequences of periodically moving cardiac structures by reordering the acquired volume series. The frame rate is especially important in studying intracardiac structures such as valve leaflet motion in which valve closing times are on the order of milliseconds. ...
Nawrot Mark M Center for Visual Neuroscience, Department of Psychology, North Dakota State University, Fargo, ND 58108, USA. - - 2012
The perception of depth from relative motion is believed to be a slow process that "builds-up" over a period of observation. However, in the case of motion parallax, the potential accuracy of the depth estimate suffers as the observer translates during the viewing period. Our recent quantitative model for the ...
Abdellatif Ady - - 2012
Purpose: To investigate experimentally the impact of intrafractional prostate motion on the delivered dose to a dominant intraprostatic lesion (DIL) using volumetric modulated arc therapy (VMAT) and intensity modulated radiation therapy (IMRT) with sequential and simultaneous boost.Methods: A series of six IMRT and VMAT treatment plans were generated, evaluated, and ...
Takahashi Daisuke - - 2012
Carbohydrates play crucial roles in a wide range of biological processes, including serious diseases. The development of novel and innovative methods for selective control of specific oligosaccharide functions has attracted much attention in the fields of chemistry, biology, and medicine. In this feature article, the development of novel chemical tools, ...
Aptekar Jacob W JW Howard Hughes Medical Institute, Department of Integrative Biology and Physiology, University of California, Los Angeles, Los Angeles, CA 90095, - - 2012
Visual figures may be distinguished based on elementary motion or higher-order non-Fourier features, and flies track both. The canonical elementary motion detector, a compact computation for Fourier motion direction and amplitude, can also encode higher-order signals provided elaborate preprocessing. However, the way in which a fly tracks a moving figure ...
Balankin Alexander S - - 2012
We study the effect of weak vibrations on the imbibition of water in granular media. In our experiments, we have observed that as soon as the vibration is applied, an initially pinned wetting front advances in the direction of imbibition. We found that the front motion is governed by the ...
Clark Marin Kristen - - 2012
Because the inertia of tectonic plates is negligible, plate velocities result from the balance of forces acting at plate margins and along their base. Observations of past plate motion derived from marine magnetic anomalies provide evidence of how continental deformation may contribute to plate driving forces. A decrease in convergence ...
Arena A - - 2012
The purpose of this study was to determine the relative contributions of local element speed and/or spatial displacement to age-related deficits in global motion processing. Motion coherence thresholds (79% correct) were measured for discriminating the direction of translational random dot kinematograms (RDKs) as a function of dot speed and spatial ...
Hock Howard S - - 2012
A new method is described for determining how the visual system resolves ambiguities in the compositional structure of multi-surface objects; i.e., how the surfaces of objects are grouped together to form a hierarchical structure. The method entails dynamic grouping motion, a high level process in which changes in a surface ...
Makin Alexis D J - - 2012
Repetitive auditory stimulation (with click trains) and visual velocity signals both have intriguing effects on the subjective passage of time. Previous studies have established that prior presentation of auditory clicks increases the subjective duration of subsequent sensory input, and that faster moving stimuli are also judged to have been presented ...
Seno Takeharu - - 2012
Visually induced illusions of self-motion (vection) are often induced using constant velocity optic flow. However, adding simulated viewpoint jitter and oscillation to these displayscan significantly improve the vection experience (especially when this jitter/oscillation is orthogonal to the constant flow component - Nakamura, 2010; Palmisano et al., 2008). In the present ...
Otten Marcus - - 2012
Intracellular transport is a complex interplay of ballistic transport along filaments and of diffusive motion, reliably delivering material and allowing for cell differentiation, migration, and proliferation. The diffusive regime, including subdiffusive, Brownian, and superdiffusive motion, is of particular interest for inferring information about the dynamics of the cytoskeleton morphology during ...
Jin Jing - - 2012
Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain-computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, ...
Antón-Méndez Inés - - 2012
The present study uses tip-of-the-tongue (TOT) states as a unique source of evidence to test the hypothesis of lexical access benefits for homophones-that is, whether low-frequency homophones, such as tee, inherit the lexical access benefits of their high-frequency homophonic counterparts, such as tea. We compared retrieval success rates for low-frequency ...
Karmonik Christof - - 2012
To quantify longitudinal changes in intra-arterial septum (IS) motion with two-dimensional (2D) phase-contrast magnetic resonance imaging (2D pcMRI) in type B aortic dissections (AD) to improve the understanding of AD and its midterm development. From a database of 42 patients who underwent a dynamic magnetic resonance imaging (MRI) examination at ...
Ghosh Attreyee - - 2012
Delineating the driving forces behind plate motions is important for understanding the processes that have shaped Earth throughout its history. However, the accurate prediction of plate motions, boundary-zone deformation, rigidity, and stresses remains a difficult frontier in numerical modeling. We present a global dynamic model that produces a good fit ...
Hutchinson Claire V - - 2012
The consequences of visual decline in aging have a fundamental and wide-reaching impact on age-related quality of life. It is of concern therefore that evidence suggests that normal aging is accompanied by impairments in the ability to effectively encode global motion. Global motion perception is a fundamentally important process. It ...
Weschke Sarah - - 2012
Although a moderate blood alcohol concentration already affects attention, an effect on early visual processing is still questionable. Using psychophysical measures and visually evoked potentials (VEP), we examined the effects of alcohol on the processing of contrast and motion features. In our tasks, two lateralized stimuli were briefly presented, and ...
Vousdoukas M I - - 2012
This article presents a Matlab-based stereo-vision motion tracking system (SVMT) for the detection of human motor reactivity elicited by sensory stimulation. It is a low-cost, non-intrusive system supported by Graphical User Interface (GUI) software, and has been successfully tested and integrated in a broad array of physiological recording devices at ...
Debono Kurt - - 2012
To pursue a small target moving in front of a drifting background, motion vectors from the target need to be integrated and segmented from those belonging to the background. Smooth pursuit eye movements typically integrate target and background directions initially and after some time shift towards the veridical target direction. ...
Skliros Aris - - 2012
Loops in proteins that connect secondary structures such as alpha-helix and beta-sheet, are often on the surface and may play a critical role in some functions of a protein. The mobility of loops is central for the motional freedom and flexibility requirements of active-site loops and may play a critical ...
Prete Frederick R - - 2012
In comparison to other similarly sized mantis species examined in previous studies, Euchomenella macrops has a significantly smaller head, shorter foreleg tibia, but longer prothorax which have been interpreted as specializations for the capture of smaller, slower prey. We tested this conjecture by assessing the rates at which computer generated ...
Cheng Joseph Y JY Magnetic Resonance Systems Research Laboratory, Department of Electrical Engineering, Stanford University, Stanford, California, USA. - - 2012
MR scans are sensitive to motion effects due to the scan duration. To properly suppress artifacts from nonrigid body motion, complex models with elements such as translation, rotation, shear, and scaling have been incorporated into the reconstruction pipeline. However, these techniques are computationally intensive and difficult to implement for online ...
Maus Gerrit W GW Department of Psychology, University of California Berkeley, Berkeley, CA 94720, USA. - - 2013
How does the visual system assign the perceived position of a moving object? This question is surprisingly complex, since sluggish responses of photoreceptors and transmission delays along the visual pathway mean that visual cortex does not have immediate information about a moving object's position. In the flash-lag effect (FLE), a ...
Vandemeulebroucke Jef - - 2012
Purpose: Deformable registration generally relies on the assumption that the sought spatial transformation is smooth. Yet, breathing motion involves sliding of the lung with respect to the chest wall, causing a discontinuity in the motion field, and the smoothness assumption can lead to poor matching accuracy. In response, alternative registration ...
Alcock Alison - - 2012
Initial ball flight characteristics of curve and instep kicks were investigated. Fifteen international female footballers performed curve and instep kicks from a distance of 20 m from goal and at a 1 m2 target. Seventeen Vicon cameras tracked three-dimensional coordinates of four reflective markers adhered to the ball. Ball flight ...
Huisman Sander G - - 2012
We present accurate measurements of the relative motion and deformation of two large bubbles released consecutively in a quiescent liquid confined in a thin-gap cell. Although the second injected bubble was smaller, we observed that, in all cases, it accelerated and caught up with the leading bubble. This acceleration is ...
Auvray Roman - - 2012
Based on results from the literature, a description of sound generation in a recorder is developed. Linear and non-linear analysis are performed to study the dependence of the frequency on the jet velocity. The linear analysis predicts that the frequency is a function of the jet velocity. The non-linear resolution ...
Font Enrique - - 2012
Under certain circumstances, prey may inform potential predators of their unprofitability by means of pursuit-deterrent signals. The evidence for pursuit-deterrent signaling in reptiles is scant and taxonomically biased. Wall lizards, Podarcis muralis (Squamata: Lacertidae) produce several distinct types of stereotyped foot shake displays, of which one, performed in antipredator contexts, ...
Eddins David A - - 2012
The coordinate response measure (CRM) corpus has gained broad acceptance as a research tool for investigating speech intelligibility in background competition and has been widely used in studies of informational masking. The purpose of this study is to establish the psychometric characteristics of CRM target-word identification in various backgrounds with ...
Courtney Michael W - - 2012
The sound of a bullet hitting a target is sometimes discernable in an audio recording of a shooting event and can be used to determine the distance from shooter to target. This paper provides an example where the microphone is adjacent to the shooter and presents the simple mathematics needed ...
Jain S - - 2012
This paper studies the problem of 3D-rigid motion invariant texture discrimination for discrete 3D-textures that are spatially homogeneous by modeling them as stationary Gaussian random fields. The latter property and our formulation of a 3D-rigid motion of a texture reduce the problem to the study of 3D-rotations of discrete textures. ...
Kuhlman Thomas S - - 2012
We found that specific nuclear motion along low-frequency modes is effective in coupling electronic states and that this motion prevail in some small molecules. Thus, in direct contradiction to what is expected based on the standard models, the internal conversion process can proceed faster for smaller molecules. Specifically, we focus ...
Linnenschmidt Meike - - 2012
Animals that use echolocation (biosonar) listen to acoustic signals with a large range of intensities, because echo levels vary with the fourth power of the animal's distance to the target. In man-made sonar, engineers apply automatic gain control to stabilize the echo energy levels, thereby rendering them independent of distance ...
Zimmermann Juliane - - 2012
Cells migrate through a crowded environment during processes such as metastasis or wound healing, and must generate and withstand substantial forces. The cellular motility responses to environmental forces are represented by their force-velocity relation, which has been measured for fish keratocytes but remains unexplained. Even pN opposing forces slow down ...
Bai Yan - - 2012
In this study, heterodyne detection is adopted to measure the velocity of a target simulated by a rapidly rotating plate by using a mode-locked pulse laser as the resource. The coherent beat frequency of the signal light reflected by target and local oscillation light occurred on the surface of the ...
Saito Hide-Aki - - 2012
The neural representation of motion aftereffects induced by various visual flows (translational, rotational, motion-in-depth, and translational transparent flows) was studied under the hypothesis that the imbalances in discharge activities would occur in favor in the direction opposite to the adapting stimulation in the monkey MST cells (cells in the medial ...
Campos Daniel - - 2012
Random search theory has been previously explored for both continuous and intermittent scanning modes with full target detection capacity. Here we present a new class of random search problems in which a single searcher performs flights of random velocities, the detection probability when it passes over a target location being ...
Bauer Markus - - 2012
Oscillatory synchronization of neuronal populations has been proposed to play a role in perceptual integration and attentional processing. However, some conflicting evidence has been found with respect to its causal relevance for sensory processing, particularly when using flickering visual stimuli with the aim of driving oscillations. We tested psychophysically whether ...
Teramoto Wataru - - 2012
Auditory temporal or semantic information often modulates visual motion events. However, the effects of auditory spatial information on visual motion perception were reported to be absent or of smaller size at perceptual level. This could be caused by a superiority of vision over hearing in reliability of motion information. Here, ...
Pavan Andrea - - 2012
In the present study, we investigated whether motion streaks, produced by fast moving dots Geisler 1999, distort the positional map of stationary flashed objects producing the well-known motion-induced position shift illusion (MIPS). The illusion relies on motion-processing mechanisms that induce local distortions in the positional map of the stimulus which ...
Bhardwaj Rishi - - 2012
Sensory storage shows a short-lived part-report advantage that survives an aftercoming visual noise pattern (Smithson & Mollon, 2006). We tested whether such an advantage survives different types of high-contrast mask. The target was a 3 × 4 array of digits. The mask could be (a) a noise pattern, (b) an ...
Daye Pierre M - - 2012
We examined subjects' behavior when they tracked periodic oscillating targets moving along a randomly oriented ramp with the head free to move. This study focuses on the effect of target motion direction on pursuit performance and on head tracking strategies used by human subjects to coordinate eye and head movements. ...
Hay Sam - - 2012
Fast motions (femtosecond to picosecond) and their potential involvement during enzyme-catalysed reactions have ignited considerable interest in recent years. Their influence on reaction chemistry has been inferred indirectly from studies of the anomalous temperature dependence of kinetic isotope effects and computational simulations. But can such motion reduce the width and ...
Au Ricky K C - - 2012
Time perception of visual events depends on the visual attributes of the scene. Previous studies reported that motion of object can induce an illusion of lengthened time. In the present study, we asked the question whether such time dilation effect depends on the actual physical motion of the object (spatiotopic ...
Malgaretti Paolo - - 2012
We analyze the rectified motion of a Brownian particle in a confined environment. We show the emergence of strong cooperativity between the inherent rectification of the ratchet mechanism and the entropic bias of the fluctuations caused by spatial confinement. Net particle transport may develop even in situations where separately the ...
Yamamoto Kentaro - - 2012
Several studies have shown that visual motion distorts perceived duration: The duration of fast-moving stimuli is judged to be longer than the same duration of stationary or slow-moving stimuli. However, it is still unclear which stages of motion processing are involved in this apparent dilation of the perceived duration. In ...
Ridgway S H - - 2012
Bottlenose dolphins (Tursiops truncatus) wore opaque suction cups over their eyes while stationing behind an acoustically opaque door. This put the dolphins in a known position and orientation. When the door opened, the dolphin clicked to detect targets. Trainers specified that Dolphin S emit a whistle if the target was ...
1 2 3 4 5 6 7 8 9 10 >