Revealing the Relationship between Reading Interest and Critical Thinking Skills through Remap GI and Remap Jigsaw

ERIC Educational Resources Information Center

Zubaidah, Siti; Corebima, Aloysius Duran; Mahanal, Susriyati; Mistianah

2018-01-01

The aim of this research was to reveal the relationship between student's reading interest and critical thinking skills through Reading Concept Map Group Investigation (Remap GI) and Reading Concept Map Jigsaw (Remap Jigsaw) learning models. To do so, two science classes from first grade of two Senior High Schools in Malang, Indonesia were…

Common-Path Interferometric Wavefront Sensing for Space Telescopes

NASA Technical Reports Server (NTRS)

Wallace, James Kent

2011-01-01

This paper presents an optical configuration for a common-path phase-shifting interferometric wavefront sensor.1 2 This sensor has a host of attractive features which make it well suited for space-based adaptive optics. First, it is strictly reflective and therefore operates broadband, second it is common mode and therefore does not suffer from systematic errors (like vibration) that are typical in other interferometers, third it is a phase-shifting interferometer and therefore benefits from both the sensitivity of interferometric sensors as well as the noise rejection afforded by synchronous detection. Unlike the Shack-Hartman wavefront sensor, it has nearly uniform sensitivity to all pupil modes. Optical configuration, theory and simulations for such a system will be discussed along with predicted performance.

Long Baseline Nulling Interferometry with the Keck Telescopes: A Progress Report

NASA Technical Reports Server (NTRS)

Mennesson, Bertrand; Akeson, R.; Appleby, E.; Bell, J.; Booth, A.; Colavita, M. M.; Crawford, S.; Creech-Eakman, M. J.; Dahl, W.; Fanson, J.;

Transfer of contextual cueing in full-icon display remapping.

PubMed

Shi, Zhuanghua; Zang, Xuelian; Jia, Lina; Geyer, Thomas; Müller, Hermann J

2013-02-25

Invariant spatial context can expedite visual search, an effect that is known as contextual cueing (e.g., Chun & Jiang, 1998). However, disrupting learned display configurations abolishes the effect. In current touch-based mobile devices, such as the iPad, icons are shuffled and remapped when the display mode is changed. However, such remapping also disrupts the spatial relationships between icons. This may hamper usability. In the present study, we examined the transfer of contextual cueing in four different methods of display remapping: position-order invariant, global rotation, local invariant, and central invariant. We used full-icon landscape mode for training and both landscape and portrait modes for testing, to check whether the cueing transfers to portrait mode. The results showed transfer of contextual cueing but only with the local invariant and the central invariant remapping methods. We take the results to mean that the predictability of target locations is a crucial factor for the transfer of contextual cueing and thus icon remapping design for mobile devices.

Extinction of Learned Fear Induces Hippocampal Place Cell Remapping

PubMed Central

Wang, Melissa E.; Yuan, Robin K.; Keinath, Alexander T.; Ramos Álvarez, Manuel M.

2015-01-01

The extinction of learned fear is a hippocampus-dependent process thought to embody new learning rather than erasure of the original fear memory, although it is unknown how these competing contextual memories are represented in the hippocampus. We previously demonstrated that contextual fear conditioning results in hippocampal place cell remapping and long-term stabilization of novel representations. Here we report that extinction learning also induces place cell remapping in C57BL/6 mice. Specifically, we observed cells that preferentially remapped during different stages of learning. While some cells remapped in both fear conditioning and extinction, others responded predominantly during extinction, which may serve to modify previous representations as well as encode new safe associations. Additionally, we found cells that remapped primarily during fear conditioning, which could facilitate reacquisition of the original fear association. Moreover, we also observed cells that were stable throughout learning, which may serve to encode the static aspects of the environment. The short-term remapping observed during extinction was not found in animals that did not undergo fear conditioning, or when extinction was conducted outside of the conditioning context. Finally, conditioning and extinction produced an increase in spike phase locking to the theta and gamma frequencies. However, the degree of remapping seen during conditioning and extinction only correlated with gamma synchronization. Our results suggest that the extinction learning is a complex process that involves both modification of pre-existing memories and formation of new ones, and these traces coexist within the same hippocampal representation. PMID:26085635

Optimal dynamic remapping of parallel computations

NASA Technical Reports Server (NTRS)

Nicol, David M.; Reynolds, Paul F., Jr.

1987-01-01

A large class of computations are characterized by a sequence of phases, with phase changes occurring unpredictably. The decision problem was considered regarding the remapping of workload to processors in a parallel computation when the utility of remapping and the future behavior of the workload is uncertain, and phases exhibit stable execution requirements during a given phase, but requirements may change radically between phases. For these problems a workload assignment generated for one phase may hinder performance during the next phase. This problem is treated formally for a probabilistic model of computation with at most two phases. The fundamental problem of balancing the expected remapping performance gain against the delay cost was addressed. Stochastic dynamic programming is used to show that the remapping decision policy minimizing the expected running time of the computation has an extremely simple structure. Because the gain may not be predictable, the performance of a heuristic policy that does not require estimnation of the gain is examined. The heuristic method's feasibility is demonstrated by its use on an adaptive fluid dynamics code on a multiprocessor. The results suggest that except in extreme cases, the remapping decision problem is essentially that of dynamically determining whether gain can be achieved by remapping after a phase change. The results also suggest that this heuristic is applicable to computations with more than two phases.

High resolution broad-band spectroscopy in the NIR using the Triplespec externally dispersed interferometer at the Hale telescope

NASA Astrophysics Data System (ADS)

Erskine, David J.; Edelstein, J.; Sirk, M.; Wishnow, E.; Ishikawa, Y.; McDonald, E.; Shourt, W. V.

2014-07-01

High resolution broad-band spectroscopy at near-infrared wavelengths has been performed using externally dis- persed interferometry (EDI) at the Hale telescope at Mt. Palomar. The EDI technique uses a field-widened Michelson interferometer in series with a dispersive spectrograph, and is able to recover a spectrum with a resolution 4 to 10 times higher than the existing grating spectrograph. This method increases the resolution well beyond the classical limits enforced by the slit width and the detector pixel Nyquist limit and, in principle, decreases the effect of pupil variation on the instrument line-shape function. The EDI technique permits arbi- trarily higher resolution measurements using the higher throughput, lower weight, size, and expense of a lower resolution spectrograph. Observations of many stars were performed with the TEDI interferometer mounted within the central hole of the 200 inch primary mirror. Light from the interferometer was then dispersed by the TripleSpec near-infrared echelle spectrograph. Continuous spectra between 950 and 2450 nm with a resolution as high as ~27,000 were recovered from data taken with TripleSpec at a native resolution of ˜2,700. Aspects of data analysis for interferometric spectral reconstruction are described. This technique has applications in im- proving measurements of high-resolution stellar template spectra, critical for precision Doppler velocimetry using conventional spectroscopic methods. A new interferometer to be applied for this purpose at visible wavelengths is under construction.

The background is remapped across saccades.

PubMed

Cha, Oakyoon; Chong, Sang Chul

2014-02-01

Physiological studies have found that neurons prepare for impending eye movements, showing anticipatory responses to stimuli presented at the location of the post-saccadic receptive fields (RFs) (Wurtz in Vis Res 48:2070-2089, 2008). These studies proposed that visual neurons with shifting RFs prepared for the stimuli they would process after an impending saccade. Additionally, psychophysical studies have shown behavioral consequences of those anticipatory responses, including the transfer of aftereffects (Melcher in Nat Neurosci 10:903-907, 2007) and the remapping of attention (Rolfs et al. in Nat Neurosci 14:252-258, 2011). As the physiological studies proposed, the shifting RF mechanism explains the transfer of aftereffects. Recently, a new mechanism based on activation transfer via a saliency map was proposed, which accounted for the remapping of attention (Cavanagh et al. in Trends Cogn Sci 14:147-153, 2010). We hypothesized that there would be different aspects of the remapping corresponding to these different neural mechanisms. This study found that the information in the background was remapped to a similar extent as the figure, provided that the visual context remained stable. We manipulated the status of the figure and the ground in the saliency map and showed that the manipulation modulated the remapping of the figure and the ground in different ways. These results suggest that the visual system has an ability to remap the background as well as the figure, but lacks the ability to modulate the remapping of the background based on the visual context, and that different neural mechanisms might work together to maintain visual stability across saccades.

Image remapping strategies applied as protheses for the visually impaired

NASA Technical Reports Server (NTRS)

Johnson, Curtis D.

1993-01-01

Maculopathy and retinitis pigmentosa (rp) are two vision defects which render the afflicted person with impaired ability to read and recognize visual patterns. For some time there has been interest and work on the use of image remapping techniques to provide a visual aid for individuals with these impairments. The basic concept is to remap an image according to some mathematical transformation such that the image is warped around a maculopathic defect (scotoma) or within the rp foveal region of retinal sensitivity. NASA/JSC has been pursuing this research using angle invariant transformations with testing of the resulting remapping using subjects and facilities of the University of Houston, College of Optometry. Testing is facilitated by use of a hardware device, the Programmable Remapper, to provide the remapping of video images. This report presents the results of studies of alternative remapping transformations with the objective of improving subject reading rates and pattern recognition. In particular a form of conformal transformation was developed which provides for a smooth warping of an image around a scotoma. In such a case it is shown that distortion of characters and lines of characters is minimized which should lead to enhanced character recognition. In addition studies were made of alternative transformations which, although not conformal, provide for similar low character distortion remapping. A second, non-conformal transformation was studied for remapping of images to aid rp impairments. In this case a transformation was investigated which allows remapping of a vision field into a circular area representing the foveal retina region. The size and spatial representation of the image are selectable. It is shown that parametric adjustments allow for a wide variation of how a visual field is presented to the sensitive retina. This study also presents some preliminary considerations of how a prosthetic device could be implemented in a practical sense, vis-a-vis, size, weight and portability.

Quasi-conformal remapping for compensation of human visual field defects - Advances in image remapping for human field defects

NASA Technical Reports Server (NTRS)

Juday, Richard D.; Loshin, David S.

1989-01-01

Image coordinate transformations are investigated for possible use in a low vision aid for human patients. These patients typically have field defects with localized retinal dysfunction predominately central (age related maculopathy) or peripheral (retinitis pigmentosa). Previously simple eccentricity-only remappings which do not maintain conformality were shown. Initial attempts on developing images which hold quasi-conformality after remapping are presented. Although the quasi-conformal images may have less local distortion, there are discontinuities in the image which may counterindicate this type of transformation for the low vision application.

Regional Environmental Monitoring and Assessment Program Data (REMAP)

EPA Pesticide Factsheets

The Regional Environmental Monitoring and Assessment Program (REMAP) was initiated to test the applicability of the Environmental Monitoring and Assessment Program (EMAP) approach to answer questions about ecological conditions at regional and local scales. Using EMAP's statistical design and indicator concepts, REMAP conducts projects at smaller geographic scales and in shorter time frames than the national EMAP program.

The piecewise-linear predictor-corrector code - A Lagrangian-remap method for astrophysical flows

NASA Technical Reports Server (NTRS)

Lufkin, Eric A.; Hawley, John F.

1993-01-01

We describe a time-explicit finite-difference algorithm for solving the nonlinear fluid equations. The method is similar to existing Eulerian schemes in its use of operator-splitting and artificial viscosity, except that we solve the Lagrangian equations of motion with a predictor-corrector and then remap onto a fixed Eulerian grid. The remap is formulated to eliminate errors associated with coordinate singularities, with a general prescription for remaps of arbitrary order. We perform a comprehensive series of tests on standard problems. Self-convergence tests show that the code has a second-order rate of convergence in smooth, two-dimensional flow, with pressure forces, gravity, and curvilinear geometry included. While not as accurate on idealized problems as high-order Riemann-solving schemes, the predictor-corrector Lagrangian-remap code has great flexibility for application to a variety of astrophysical problems.

Quasi-Conformal Remapping For Compensation Of Human Visual Field Defects: Advances In Image Remapping For Human Field Defects

NASA Astrophysics Data System (ADS)

Juday, Richard D.; Loshin, David S.

1989-06-01

We are investigating image coordinate transformations possibly to be used in a low vision aid for human patients. These patients typically have field defects with localized retinal dysfunction predominately central (age related maculopathy) or peripheral (retinitis pigmentosa). Previously we have shown simple eccentricity-only remappings which do not maintain conformality. In this report we present our initial attempts on developing images which hold quasi-conformality after remapping. Although the quasi-conformal images may have less local distortion, there are discontinuities in the image which may counterindicate this type of transformation for the low vision application.

Wavefront measurements of phase plates combining a point-diffraction interferometer and a Hartmann-Shack sensor.

PubMed

Bueno, Juan M; Acosta, Eva; Schwarz, Christina; Artal, Pablo

2010-01-20

A dual setup composed of a point diffraction interferometer (PDI) and a Hartmann-Shack (HS) wavefront sensor was built to compare the estimates of wavefront aberrations provided by the two different and complementary techniques when applied to different phase plates. Results show that under the same experimental and fitting conditions both techniques provide similar information concerning the wavefront aberration map. When taking into account all Zernike terms up to 6th order, the maximum difference in root-mean-square wavefront error was 0.08 microm, and this reduced up to 0.03 microm when excluding lower-order terms. The effects of the pupil size and the order of the Zernike expansion used to reconstruct the wavefront were evaluated. The combination of the two techniques can accurately measure complicated phase profiles, combining the robustness of the HS and the higher resolution and dynamic range of the PDI.

Spatial updating in human parietal cortex

NASA Technical Reports Server (NTRS)

Merriam, Elisha P.; Genovese, Christopher R.; Colby, Carol L.

2003-01-01

Single neurons in monkey parietal cortex update visual information in conjunction with eye movements. This remapping of stimulus representations is thought to contribute to spatial constancy. We hypothesized that a similar process occurs in human parietal cortex and that we could visualize it with functional MRI. We scanned subjects during a task that involved remapping of visual signals across hemifields. We observed an initial response in the hemisphere contralateral to the visual stimulus, followed by a remapped response in the hemisphere ipsilateral to the stimulus. We ruled out the possibility that this remapped response resulted from either eye movements or visual stimuli alone. Our results demonstrate that updating of visual information occurs in human parietal cortex.

Testing the TPF Interferometry Approach before Launch

NASA Technical Reports Server (NTRS)

Serabyn, Eugene; Mennesson, Bertrand

2006-01-01

One way to directly detect nearby extra-solar planets is via their thermal infrared emission, and with this goal in mind, both NASA and ESA are investigating cryogenic infrared interferometers. Common to both agencies' approaches to faint off-axis source detection near bright stars is the use of a rotating nulling interferometer, such as the Terrestrial Planet Finder interferometer (TPF-I), or Darwin. In this approach, the central star is nulled, while the emission from off-axis sources is transmitted and modulated by the rotation of the off-axis fringes. Because of the high contrasts involved, and the novelty of the measurement technique, it is essential to gain experience with this technique before launch. Here we describe a simple ground-based experiment that can test the essential aspects of the TPF signal measurement and image reconstruction approaches by generating a rotating interferometric baseline within the pupil of a large singleaperture telescope. This approach can mimic potential space-based interferometric configurations, and allow the extraction of signals from off-axis sources using the same algorithms proposed for the space-based missions. This approach should thus allow for testing of the applicability of proposed signal extraction algorithms for the detection of single and multiple near-neighbor companions...

ReMap 2018: an updated atlas of regulatory regions from an integrative analysis of DNA-binding ChIP-seq experiments

PubMed Central

Chèneby, Jeanne; Gheorghe, Marius; Artufel, Marie

2018-01-01

Abstract With this latest release of ReMap (http://remap.cisreg.eu), we present a unique collection of regulatory regions in human, as a result of a large-scale integrative analysis of ChIP-seq experiments for hundreds of transcriptional regulators (TRs) such as transcription factors, transcriptional co-activators and chromatin regulators. In 2015, we introduced the ReMap database to capture the genome regulatory space by integrating public ChIP-seq datasets, covering 237 TRs across 13 million (M) peaks. In this release, we have extended this catalog to constitute a unique collection of regulatory regions. Specifically, we have collected, analyzed and retained after quality control a total of 2829 ChIP-seq datasets available from public sources, covering a total of 485 TRs with a catalog of 80M peaks. Additionally, the updated database includes new search features for TR names as well as aliases, including cell line names and the ability to navigate the data directly within genome browsers via public track hubs. Finally, full access to this catalog is available online together with a TR binding enrichment analysis tool. ReMap 2018 provides a significant update of the ReMap database, providing an in depth view of the complexity of the regulatory landscape in human. PMID:29126285

The Generalization of Visuomotor Learning to Untrained Movements and Movement Sequences Based on Movement Vector and Goal Location Remapping

PubMed Central

Wu, Howard G.

2013-01-01

The planning of goal-directed movements is highly adaptable; however, the basic mechanisms underlying this adaptability are not well understood. Even the features of movement that drive adaptation are hotly debated, with some studies suggesting remapping of goal locations and others suggesting remapping of the movement vectors leading to goal locations. However, several previous motor learning studies and the multiplicity of the neural coding underlying visually guided reaching movements stand in contrast to this either/or debate on the modes of motor planning and adaptation. Here we hypothesize that, during visuomotor learning, the target location and movement vector of trained movements are separately remapped, and we propose a novel computational model for how motor plans based on these remappings are combined during the control of visually guided reaching in humans. To test this hypothesis, we designed a set of experimental manipulations that effectively dissociated the effects of remapping goal location and movement vector by examining the transfer of visuomotor adaptation to untrained movements and movement sequences throughout the workspace. The results reveal that (1) motor adaptation differentially remaps goal locations and movement vectors, and (2) separate motor plans based on these features are effectively averaged during motor execution. We then show that, without any free parameters, the computational model we developed for combining movement-vector-based and goal-location-based planning predicts nearly 90% of the variance in novel movement sequences, even when multiple attributes are simultaneously adapted, demonstrating for the first time the ability to predict how motor adaptation affects movement sequence planning. PMID:23804099

Edge remap for solids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamm, James R.; Love, Edward; Robinson, Allen C.

We review the edge element formulation for describing the kinematics of hyperelastic solids. This approach is used to frame the problem of remapping the inverse deformation gradient for Arbitrary Lagrangian-Eulerian (ALE) simulations of solid dynamics. For hyperelastic materials, the stress state is completely determined by the deformation gradient, so remapping this quantity effectively updates the stress state of the material. A method, inspired by the constrained transport remap in electromagnetics, is reviewed, according to which the zero-curl constraint on the inverse deformation gradient is implicitly satisfied. Open issues related to the accuracy of this approach are identified. An optimization-based approachmore » is implemented to enforce positivity of the determinant of the deformation gradient. The efficacy of this approach is illustrated with numerical examples.« less

Perisaccadic Updating of Visual Representations and Attentional States: Linking Behavior and Neurophysiology

PubMed Central

Marino, Alexandria C.; Mazer, James A.

2016-01-01

During natural vision, saccadic eye movements lead to frequent retinal image changes that result in different neuronal subpopulations representing the same visual feature across fixations. Despite these potentially disruptive changes to the neural representation, our visual percept is remarkably stable. Visual receptive field remapping, characterized as an anticipatory shift in the position of a neuron’s spatial receptive field immediately before saccades, has been proposed as one possible neural substrate for visual stability. Many of the specific properties of remapping, e.g., the exact direction of remapping relative to the saccade vector and the precise mechanisms by which remapping could instantiate stability, remain a matter of debate. Recent studies have also shown that visual attention, like perception itself, can be sustained across saccades, suggesting that the attentional control system can also compensate for eye movements. Classical remapping could have an attentional component, or there could be a distinct attentional analog of visual remapping. At this time we do not yet fully understand how the stability of attentional representations relates to perisaccadic receptive field shifts. In this review, we develop a vocabulary for discussing perisaccadic shifts in receptive field location and perisaccadic shifts of attentional focus, review and synthesize behavioral and neurophysiological studies of perisaccadic perception and perisaccadic attention, and identify open questions that remain to be experimentally addressed. PMID:26903820

ReMap 2018: an updated atlas of regulatory regions from an integrative analysis of DNA-binding ChIP-seq experiments.

PubMed

Chèneby, Jeanne; Gheorghe, Marius; Artufel, Marie; Mathelier, Anthony; Ballester, Benoit

2018-01-04

With this latest release of ReMap (http://remap.cisreg.eu), we present a unique collection of regulatory regions in human, as a result of a large-scale integrative analysis of ChIP-seq experiments for hundreds of transcriptional regulators (TRs) such as transcription factors, transcriptional co-activators and chromatin regulators. In 2015, we introduced the ReMap database to capture the genome regulatory space by integrating public ChIP-seq datasets, covering 237 TRs across 13 million (M) peaks. In this release, we have extended this catalog to constitute a unique collection of regulatory regions. Specifically, we have collected, analyzed and retained after quality control a total of 2829 ChIP-seq datasets available from public sources, covering a total of 485 TRs with a catalog of 80M peaks. Additionally, the updated database includes new search features for TR names as well as aliases, including cell line names and the ability to navigate the data directly within genome browsers via public track hubs. Finally, full access to this catalog is available online together with a TR binding enrichment analysis tool. ReMap 2018 provides a significant update of the ReMap database, providing an in depth view of the complexity of the regulatory landscape in human. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Right-hemispheric dominance for visual remapping in humans.

PubMed

Pisella, L; Alahyane, N; Blangero, A; Thery, F; Blanc, S; Pelisson, D

2011-02-27

We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans--and present additional original data--which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward. This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized.

Right-hemispheric dominance for visual remapping in humans

PubMed Central

Pisella, L.; Alahyane, N.; Blangero, A.; Thery, F.; Blanc, S.; Pelisson, D.

2011-01-01

We review evidence showing a right-hemispheric dominance for visuo-spatial processing and representation in humans. Accordingly, visual disorganization symptoms (intuitively related to remapping impairments) are observed in both neglect and constructional apraxia. More specifically, we review findings from the intervening saccade paradigm in humans—and present additional original data—which suggest a specific role of the asymmetrical network at the temporo-parietal junction (TPJ) in the right hemisphere in visual remapping: following damage to the right dorsal posterior parietal cortex (PPC) as well as part of the corpus callosum connecting the PPC to the frontal lobes, patient OK in a double-step saccadic task exhibited an impairment when the second saccade had to be directed rightward. This singular and lateralized deficit cannot result solely from the patient's cortical lesion and, therefore, we propose that it is due to his callosal lesion that may specifically interrupt the interhemispheric transfer of information necessary to execute accurate rightward saccades towards a remapped target location. This suggests a specialized right-hemispheric network for visuo-spatial remapping that subsequently transfers target location information to downstream planning regions, which are symmetrically organized. PMID:21242144

A Mach-Zehnder interferometer based on orbital angular momentum for improved vortex coronagraph efficiency

NASA Astrophysics Data System (ADS)

Piron, P.; Delacroix, C.; Huby, E.; Mawet, D.; Karlsson, M.; Ruane, G.; Habraken, S.; Absil, O.; Surdej, J.

2015-09-01

The Annular Groove Phase Mask (AGPM) is a vectorial vortex phase mask. It acts as a half-wave plate with a radial fast axis orientation operating in the mid infrared domain. When placed at the focus of a telescope element provides a continuous helical phase ramp for an on axis sources, which creates the orbital angular momentum. Thanks to that phase, the intensity of the central source is canceled by a down-stream pupil stop, while the off axis sources are not affected. However due to experimental conditions the nulling is hardly perfect. To improve the null, a Mach-Zehnder interferometer containing Dove prisms differently oriented can be proposed to sort out light based on its orbital angular momentum (OAM). Thanks to the differential rotation of the beam, a π phase shift is achieved for the on axis light affected by a non zero OAM. Therefore the contrast between the star and its faint companion is enhanced. Nevertheless, due the Dove prisms birefringence, the performance of the interferometer is relatively poor. To solve this problem, we propose to add a birefringent wave-plate in each arm to compensate this birefringence. In this paper, we will develop the mathematical model of the wave front using the Jones formalism. The performance of the interferometer is at first computed for the simple version without the birefringent plate. Then the effect of the birefringent plate is be mathematically described and the performance is re-computed.

Adaptation of Dunn Solar Telescope for Jovian Doppler spectro imaging

NASA Astrophysics Data System (ADS)

Underwood, Thomas A.; Voelz, David; Schmider, François-Xavier; Jackiewicz, Jason; Dejonghe, Julien; Bresson, Yves; Hull, Robert; Goncalves, Ivan; Gualme, Patrick; Morand, Frédéric; Preis, Olivier

2017-09-01

This paper describes instrumentation used to adapt the Dunn Solar Telescope (DST) located on Sacramento Peak in Sunspot, NM for observations using the Doppler Spectro Imager (DSI). The DSI is based on a Mach-Zehnder interferometer and measures the Doppler shift of solar lines allowing for the study of atmospheric dynamics of giant planets and the detection of their acoustic oscillations. The instrumentation is being designed and built through a collaborative effort between a French team from the Observatoire de la Cote d'Azur (OCA) that designed the DSI and a US team at New Mexico State University (NMSU). There are four major components that couple the DSI to the DST: a guider/tracker, fast steering mirror (FSM), pupil stabilizer and transfer optics. The guider/tracker processes digital video to centroid-track the planet and outputs voltages to the DST's heliostat controls. The FSM removes wavefront tip/tilt components primarily due to turbulence and the pupil stabilizer removes any slow pupil "wander" introduced by the telescope's heliostat/turret arrangement. The light received at a science port of the DST is sent through the correction and stabilization components and into the DSI. The FSM and transfer optics designs are being provided by the OCA team and serve much the same functions as they do for other telescopes at which DSI observations have been conducted. The pupil stabilization and guider are new and are required to address characteristics of the DST.

Simple Fourier optics formalism for high-angular-resolution systems and nulling interferometry.

PubMed

Hénault, François

2010-03-01

Reviewed are various designs of advanced, multiaperture optical systems dedicated to high-angular-resolution imaging or to the detection of exoplanets by nulling interferometry. A simple Fourier optics formalism applicable to both imaging arrays and nulling interferometers is presented, allowing their basic theoretical relationships to be derived as convolution or cross-correlation products suitable for fast and accurate computation. Several unusual designs, such as a "superresolving telescope" utilizing a mosaicking observation procedure or a free-flying, axially recombined interferometer are examined, and their performance in terms of imaging and nulling capacity are assessed. In all considered cases, it is found that the limiting parameter is the diameter of the individual telescopes. A final section devoted to nulling interferometry shows an apparent superiority of axial versus multiaxial recombining schemes. The entire study is valid only in the framework of first-order geometrical optics and scalar diffraction theory. Furthermore, it is assumed that all entrance subapertures are optically conjugated with their associated exit pupils.

Wavefront-aberration measurement and systematic-error analysis of a high numerical-aperture objective

NASA Astrophysics Data System (ADS)

Liu, Zhixiang; Xing, Tingwen; Jiang, Yadong; Lv, Baobin

2018-02-01

A two-dimensional (2-D) shearing interferometer based on an amplitude chessboard grating was designed to measure the wavefront aberration of a high numerical-aperture (NA) objective. Chessboard gratings offer better diffraction efficiencies and fewer disturbing diffraction orders than traditional cross gratings. The wavefront aberration of the tested objective was retrieved from the shearing interferogram using the Fourier transform and differential Zernike polynomial-fitting methods. Grating manufacturing errors, including the duty-cycle and pattern-deviation errors, were analyzed with the Fourier transform method. Then, according to the relation between the spherical pupil and planar detector coordinates, the influence of the distortion of the pupil coordinates was simulated. Finally, the systematic error attributable to grating alignment errors was deduced through the geometrical ray-tracing method. Experimental results indicate that the measuring repeatability (3σ) of the wavefront aberration of an objective with NA 0.4 was 3.4 mλ. The systematic-error results were consistent with previous analyses. Thus, the correct wavefront aberration can be obtained after calibration.

LANDFIRE Remap: A New National Baseline Product Suite

NASA Astrophysics Data System (ADS)

Dockter, D.; Peterson, B.; Picotte, J. J.; Long, J.; Tolk, B.; Callahan, K.; Davidson, A.; Earnhardt, T.

2017-12-01

LANDFIRE, also known as the Landscape Fire and Resource Management Planning Tools Program, is a vegetation, fire, and fuel characteristic data creation program managed by both the U.S. Department of Agriculture Forest Service and the U.S. Department of the Interior with involvement from The Nature Conservancy. LANDFIRE represents the first and only complete, nationally consistent collection of over 20 geo-spatial layers (e.g., vegetation type and structure, fuels, fire regimes), databases, and ecological models that can be used across multiple disciplines to support cross-boundary planning, management, and operations across all lands of the United States and insular areas. Since 2004, LANDFIRE has produced comprehensive, consistent, and scientifically based suites of mapped products and associated databases for the United States and affiliated territories. These products depict the nation's major ecosystems and wildlife habitats. Over a decade has passed since the development of the first LANDFIRE base map, and an overhaul of the data products, i.e., a "Remap", is needed to maintain their functionality and relevance. To prepare for Remap production LANDFIRE has invested in a prototyping phase that focused on exploring various input data sources and new modeling and mapping techniques. While still grounded in a solid base consisting of Landsat imagery and high-quality field observations, the prototyping efforts explored different image compositing techniques, the integration of lidar data, modeling approaches as well as other factors that will inform Remap production. Several of these various research efforts are highlighted here and are currently being integrated into an end-to-end data processing flow that will drive the Remap production. The current Remap prototype effort has focused on several study areas throughout CONUS, with additional studies anticipated for Alaska, Hawaii and the territories. The LANDFIRE Remap effort is expected to take three to four years, with production commencing in northwestern CONUS.

Clinical Verification of Image Warping as a Potential Aid for the Visually Handicapped

NASA Technical Reports Server (NTRS)

Loshin, David

1996-01-01

The bulk of this research was to designed determine potential of the Programmable Remapper (PR) as a device to enhance vision for the visually handicapped. This research indicated that remapping would have potential as a low vision device if the eye position could be monitored with feedback to specify the proper location of the remapped image. This must be accomplished at high rate so that there is no lag of the image behind the eye position. Since at this time, there is no portable eye monitor device (at a reasonable cost) that will operate under the required conditions, it would not be feasible to continue with remapping experiments for patients with central field defects. However, since patients with peripheral field defects do not have the same eye positioning requirements, they may indeed benefit from this technology. Further investigations must be performed to determine plausibility of this application of remapping.

Parallax-sensitive remapping of visual space in occipito-parietal alpha-band activity during whole-body motion

PubMed Central

Selen, L. P. J.; Medendorp, W. P.

2014-01-01

Despite the constantly changing retinal image due to eye, head, and body movements, we are able to maintain a stable representation of the visual environment. Various studies on retinal image shifts caused by saccades have suggested that occipital and parietal areas correct for these perturbations by a gaze-centered remapping of the neural image. However, such a uniform, rotational, remapping mechanism cannot work during translations when objects shift on the retina in a more complex, depth-dependent fashion due to motion parallax. Here we tested whether the brain's activity patterns show parallax-sensitive remapping of remembered visual space during whole-body motion. Under continuous recording of electroencephalography (EEG), we passively translated human subjects while they had to remember the location of a world-fixed visual target, briefly presented in front of or behind the eyes' fixation point prior to the motion. Using a psychometric approach we assessed the quality of the memory update, which had to be made based on vestibular feedback and other extraretinal motion cues. All subjects showed a variable amount of parallax-sensitive updating errors, i.e., the direction of the errors depended on the depth of the target relative to fixation. The EEG recordings show a neural correlate of this parallax-sensitive remapping in the alpha-band power at occipito-parietal electrodes. At parietal electrodes, the strength of these alpha-band modulations correlated significantly with updating performance. These results suggest that alpha-band oscillatory activity reflects the time-varying updating of gaze-centered spatial information during parallax-sensitive remapping during whole-body motion. PMID:25505108

Dissociation between Emotional Remapping of Fear and Disgust in Alexithymia

PubMed Central

Scarpazza, Cristina; Làdavas, Elisabetta; di Pellegrino, Giuseppe

2015-01-01

There is growing evidence that individuals are able to understand others’ emotions because they “embody” them, i.e., re-experience them by activating a representation of the observed emotion within their own body. One way to study emotion embodiment is provided by a multisensory stimulation paradigm called emotional visual remapping of touch (eVRT), in which the degree of embodiment/remapping of emotions is measured as enhanced detection of near-threshold tactile stimuli on one’s own face while viewing different emotional facial expressions. Here, we measured remapping of fear and disgust in participants with low (LA) and high (HA) levels of alexithymia, a personality trait characterized by a difficulty in recognizing emotions. The results showed that fear is remapped in LA but not in HA participants, while disgust is remapped in HA but not in LA participants. To investigate the hypothesis that HA might exhibit increased responses to emotional stimuli producing a heightened physical and visceral sensations, i.e., disgust, in a second experiment we investigated participants’ interoceptive abilities and the link between interoception and emotional modulations of VRT. The results showed that participants’ disgust modulations of VRT correlated with their ability to perceive bodily signals. We suggest that the emotional profile of HA individuals on the eVRT task could be related to their abnormal tendency to be focalized on their internal bodily signals, and to experience emotions in a “physical” way. Finally, we speculated that these results in HA could be due to a enhancement of insular activity during the perception of disgusted faces. PMID:26462241

Contact lens design with slope-constrained Q-type aspheres for myopia correction

NASA Astrophysics Data System (ADS)

Peng, Wei-Jei; Cheng, Yuan-Chieh; Hsu, Wei-Yao; Yu, Zong-Ru; Ho, Cheng-Fang; Abou-El-Hossein, Khaled

2017-08-01

The design of the rigid contact lens (CL) with slope-constrained Q-type aspheres for myopia correction is presented in this paper. The spherical CL is the most common type for myopia correction, however the spherical aberration (SA) caused from the pupil dilation in dark leads to the degradation of visual acuity which cannot be corrected by spherical surface. The spherical and aspheric CLs are designed respectively based on Liou's schematic eye model, and the criterion is the modulation transfer function (MTF) at the frequency of 100 line pair per mm, which corresponds to the normal vision of one arc-minute. After optimization, the MTF of the aspheric design is superior to that of the spherical design, because the aspheric surface corrects the SA for improving the visual acuity in dark. For avoiding the scratch caused from the contact profilometer, the aspheric surface is designed to match the measurability of the interferometer. The Q-type aspheric surface is employed to constrain the root-mean-square (rms) slope of the departure from a best-fit sphere directly, because the fringe density is limited by the interferometer. The maximum sag departure from a best-fit sphere is also controlled according to the measurability of the aspheric stitching interferometer (ASI). The inflection point is removed during optimization for measurability and appearance. In this study, the aspheric CL is successfully designed with Q-type aspheres for the measurability of the interferometer. It not only corrects the myopia but also eliminates the SA for improving the visual acuity in dark based on the schematic eye model.

IMPACT OF η{sub Earth} ON THE CAPABILITIES OF AFFORDABLE SPACE MISSIONS TO DETECT BIOSIGNATURES ON EXTRASOLAR PLANETS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Léger, Alain; Defrère, Denis; Malbet, Fabien

2015-08-01

We present an analytic model to estimate the capabilities of space missions dedicated to the search for biosignatures in the atmosphere of rocky planets located in the habitable zone of nearby stars. Relations between performance and mission parameters, such as mirror diameter, distance to targets, and radius of planets, are obtained. Two types of instruments are considered: coronagraphs observing in the visible, and nulling interferometers in the thermal infrared. Missions considered are: single-pupil coronagraphs with a 2.4 m primary mirror, and formation-flying interferometers with 4 × 0.75 m collecting mirrors. The numbers of accessible planets are calculated as a functionmore » of η{sub Earth}. When Kepler gives its final estimation for η{sub Earth}, the model will permit a precise assessment of the potential of each instrument. Based on current estimations, η{sub Earth} = 10% around FGK stars and 50% around M stars, the coronagraph could study in spectroscopy only ∼1.5 relevant planets, and the interferometer ∼14.0. These numbers are obtained under the major hypothesis that the exozodiacal light around the target stars is low enough for each instrument. In both cases, a prior detection of planets is assumed and a target list established. For the long-term future, building both types of spectroscopic instruments, and using them on the same targets, will be the optimal solution because they provide complementary information. But as a first affordable space mission, the interferometer looks the more promising in terms of biosignature harvest.« less

ESMPy and OpenClimateGIS: Python Interfaces for High Performance Grid Remapping and Geospatial Dataset Manipulation

NASA Astrophysics Data System (ADS)

O'Kuinghttons, Ryan; Koziol, Benjamin; Oehmke, Robert; DeLuca, Cecelia; Theurich, Gerhard; Li, Peggy; Jacob, Joseph

2016-04-01

The Earth System Modeling Framework (ESMF) Python interface (ESMPy) supports analysis and visualization in Earth system modeling codes by providing access to a variety of tools for data manipulation. ESMPy started as a Python interface to the ESMF grid remapping package, which provides mature and robust high-performance and scalable grid remapping between 2D and 3D logically rectangular and unstructured grids and sets of unconnected data. ESMPy now also interfaces with OpenClimateGIS (OCGIS), a package that performs subsetting, reformatting, and computational operations on climate datasets. ESMPy exposes a subset of ESMF grid remapping utilities. This includes bilinear, finite element patch recovery, first-order conservative, and nearest neighbor grid remapping methods. There are also options to ignore unmapped destination points, mask points on source and destination grids, and provide grid structure in the polar regions. Grid remapping on the sphere takes place in 3D Cartesian space, so the pole problem is not an issue as it can be with other grid remapping software. Remapping can be done between any combination of 2D and 3D logically rectangular and unstructured grids with overlapping domains. Grid pairs where one side of the regridding is represented by an appropriate set of unconnected data points, as is commonly found with observational data streams, is also supported. There is a developing interoperability layer between ESMPy and OpenClimateGIS (OCGIS). OCGIS is a pure Python, open source package designed for geospatial manipulation, subsetting, and computation on climate datasets stored in local NetCDF files or accessible remotely via the OPeNDAP protocol. Interfacing with OCGIS has brought GIS-like functionality to ESMPy (i.e. subsetting, coordinate transformations) as well as additional file output formats (i.e. CSV, ESRI Shapefile). ESMPy is distinguished by its strong emphasis on open source, community governance, and distributed development. The user base has grown quickly, and the package is integrating with several other software tools and frameworks. These include the Ultrascale Visualization Climate Data Analysis Tools (UV-CDAT), Iris, PyFerret, cfpython, and the Community Surface Dynamics Modeling System (CSDMS). ESMPy minimum requirements include Python 2.6, Numpy 1.6.1 and an ESMF installation. Optional dependencies include NetCDF and OCGIS-related dependencies: GDAL, Shapely, and Fiona. ESMPy is regression tested nightly, and supported on Darwin, Linux and Cray systems with the GNU compiler suite and MPI communications. OCGIS is supported on Linux, and also undergoes nightly regression testing. Both packages are installable from Anaconda channels. Upcoming development plans for ESMPy involve development of a higher order conservative grid remapping method. Future OCGIS development will focus on mesh and location stream interoperability and streamlined access to ESMPy's MPI implementation.

20th century Betula pubescens subsp. czerepanovii tree- and forest lines in Norway.

PubMed

Bryn, Anders; Potthoff, Kerstin

2017-01-01

Georeferenced tree- and forest line data has a wide range of applications and are increasingly used for e.g. monitoring of climate change impacts and range shift modelling. As part of a research project, registrations of previously re-mapped tree- and forest lines have been georeferenced. The data described in this paper contains 100 re-mapped registrations of Betula pubescens subsp. czerepanovii throughout Norway. All of the re-mapped tree- and forest line localities are georeferenced, elevation and aspect are given, elevational and spatial uncertainty are provided, and the re-mapping methods are explained. The published data weremapped for the first time between 1819 and 1963. The same sites were re-mapped between 1928 and 1996, but have until now been missing spatial coordinates. The entries contain 40 x 2 tree lines and 60 x 2 forest lines, most likely presenting the regionally highest registered tree- and forest lines at the given time. The entire material is stored and available for download through the GBIF server. Previously, the entries have been published in journals or reports, partly in Norwegian or German only. Without the provision of the spatial coordinates, the specific locations have been unknown. The material is now available for modelling and monitoring of tree- and forest line range shifts: The recordings are useful for interpretation of climate change impacts on tree- and forest lines, and the locations of re-mapped tree- and forest lines can be implemented in future monitoring projects. Since the recordings most likely provide the highest registered Betula pubescens subsp. czerepanovii locations within their specific regions, they are probably representing the contemporary physiognomic range limits.

WV R-EMAP STUDY: MULTIPLE-OBJECTIVE SAMPLING DESIGN FRAMEWORK

EPA Science Inventory

A multi-objective sampling design has been implemented through Regional Monitoring and Assessment Program (R-EMAP) support of a cooperative agreement with the state of West Virginia. Goals of the project include: 1) development and testing of a temperature-adjusted fish IBI for t...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klima, Matej; Kucharik, MIlan; Shashkov, Mikhail Jurievich

We analyze several new and existing approaches for limiting tensor quantities in the context of deviatoric stress remapping in an ALE numerical simulation of elastic flow. Remapping and limiting of the tensor component-by-component is shown to violate radial symmetry of derived variables such as elastic energy or force. Therefore, we have extended the symmetry-preserving Vector Image Polygon algorithm, originally designed for limiting vector variables. This limiter constrains the vector (in our case a vector of independent tensor components) within the convex hull formed by the vectors from surrounding cells – an equivalent of the discrete maximum principle in scalar variables.more » We compare this method with a limiter designed specifically for deviatoric stress limiting which aims to constrain the J 2 invariant that is proportional to the specific elastic energy and scale the tensor accordingly. We also propose a method which involves remapping and limiting the J 2 invariant independently using known scalar techniques. The deviatoric stress tensor is then scaled to match this remapped invariant, which guarantees conservation in terms of elastic energy.« less

DISTRIBUTION OF MERCURY IN USEPA REGION IX R-EMAP STUDY AREAS

EPA Science Inventory

Mercury distribution within U .S. EP A Region IX Regional Environmental Monitoring and Assessment Program (R-EMAP) study units is associated with geology and land-use practices. Stream water and sediment data indicate mercury is mobilized from weathering of ore bearing rock, and ...

Transverse Pupil Shifts for Adaptive Optics Non-Common Path Calibration

NASA Technical Reports Server (NTRS)

Bloemhof, Eric E.

2011-01-01

A simple new way of obtaining absolute wavefront measurements with a laboratory Fizeau interferometer was recently devised. In that case, the observed wavefront map is the difference of two cavity surfaces, those of the mirror under test and of an unknown reference surface on the Fizeau s transmission flat. The absolute surface of each can be determined by applying standard wavefront reconstruction techniques to two grids of absolute surface height differences of the mirror under test, obtained from pairs of measurements made with slight transverse shifts in X and Y. Adaptive optics systems typically provide an actuated periscope between wavefront sensor (WFS) and commonmode optics, used for lateral registration of deformable mirror (DM) to WFS. This periscope permits independent adjustment of either pupil or focal spot incident on the WFS. It would be used to give the required lateral pupil motion between common and non-common segments, analogous to the lateral shifts of the two phase contributions in the lab Fizeau. The technique is based on a completely new approach to calibration of phase. It offers unusual flexibility with regard to the transverse spatial frequency scales probed, and will give results quite quickly, making use of no auxiliary equipment other than that built into the adaptive optics system. The new technique may be applied to provide novel calibration information about other optical systems in which the beam may be shifted transversely in a controlled way.

A 3D finite element ALE method using an approximate Riemann solution

DOE PAGES

Chiravalle, V. P.; Morgan, N. R.

2016-08-09

Arbitrary Lagrangian–Eulerian finite volume methods that solve a multidimensional Riemann-like problem at the cell center in a staggered grid hydrodynamic (SGH) arrangement have been proposed. This research proposes a new 3D finite element arbitrary Lagrangian–Eulerian SGH method that incorporates a multidimensional Riemann-like problem. Here, two different Riemann jump relations are investigated. A new limiting method that greatly improves the accuracy of the SGH method on isentropic flows is investigated. A remap method that improves upon a well-known mesh relaxation and remapping technique in order to ensure total energy conservation during the remap is also presented. Numerical details and test problemmore » results are presented.« less

A 3D finite element ALE method using an approximate Riemann solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiravalle, V. P.; Morgan, N. R.

Arbitrary Lagrangian–Eulerian finite volume methods that solve a multidimensional Riemann-like problem at the cell center in a staggered grid hydrodynamic (SGH) arrangement have been proposed. This research proposes a new 3D finite element arbitrary Lagrangian–Eulerian SGH method that incorporates a multidimensional Riemann-like problem. Here, two different Riemann jump relations are investigated. A new limiting method that greatly improves the accuracy of the SGH method on isentropic flows is investigated. A remap method that improves upon a well-known mesh relaxation and remapping technique in order to ensure total energy conservation during the remap is also presented. Numerical details and test problemmore » results are presented.« less

Integration of Hand and Finger Location in External Spatial Coordinates for Tactile Localization

ERIC Educational Resources Information Center

Heed, Tobias; Backhaus, Jenny; Roder, Brigitte

2012-01-01

Tactile stimulus location is automatically transformed from somatotopic into external spatial coordinates, rendering information about the location of touch in three-dimensional space. This process is referred to as tactile remapping. Whereas remapping seems to occur automatically for the hands and feet, the fingers may constitute an exception in…

IBIS FOR FISH AND MACROINVERTEBRATES DEVELOPED FOR GREAT LAKES COASTAL WETLANDS: AN EPA REGIONAL ENVIRONMENTAL MONITORING AND ASSESSMENT PROGRAM (REMAP) PROJECT

EPA Science Inventory

The research from this REMAP project produced results that demonstrate various stages of an assessment strategy and produced tools including an inventory classification, field methods and multimetric biotic indices that are now available for use by environmental resource managers...

Compatible, energy conserving, bounds preserving remap of hydrodynamic fields for an extended ALE scheme

DOE PAGES

Burton, Donald E.; Morgan, Nathaniel Ray; Charest, Marc Robert Joseph; ...

2017-11-22

From the very origins of numerical hydrodynamics in the Lagrangian work of von Neumann and Richtmyer [83], the issue of total energy conservation as well as entropy production has been problematic. Because of well known problems with mesh deformation, Lagrangian schemes have evolved into Arbitrary Lagrangian–Eulerian (ALE) methods [39] that combine the best properties of Lagrangian and Eulerian methods. Energy issues have persisted for this class of methods. We believe that fundamental issues of energy conservation and entropy production in ALE require further examination. The context of the paper is an ALE scheme that is extended in the sense thatmore » it permits cyclic or periodic remap of data between grids of the same or differing connectivity. The principal design goals for a remap method then consist of total energy conservation, bounded internal energy, and compatibility of kinetic energy and momentum. We also have secondary objectives of limiting velocity and stress in a non-directional manner, keeping primitive variables monotone, and providing a higher than second order reconstruction of remapped variables. Particularly, the new contributions fall into three categories associated with: energy conservation and entropy production, reconstruction and bounds preservation of scalar and tensor fields, and conservative remap of nonlinear fields. Our paper presents a derivation of the methods, details of implementation, and numerical results for a number of test problems. The methods requires volume integration of polynomial functions in polytopal cells with planar facets, and the requisite expressions are derived for arbitrary order.« less

Compatible, energy conserving, bounds preserving remap of hydrodynamic fields for an extended ALE scheme

NASA Astrophysics Data System (ADS)

Burton, D. E.; Morgan, N. R.; Charest, M. R. J.; Kenamond, M. A.; Fung, J.

2018-02-01

From the very origins of numerical hydrodynamics in the Lagrangian work of von Neumann and Richtmyer [83], the issue of total energy conservation as well as entropy production has been problematic. Because of well known problems with mesh deformation, Lagrangian schemes have evolved into Arbitrary Lagrangian-Eulerian (ALE) methods [39] that combine the best properties of Lagrangian and Eulerian methods. Energy issues have persisted for this class of methods. We believe that fundamental issues of energy conservation and entropy production in ALE require further examination. The context of the paper is an ALE scheme that is extended in the sense that it permits cyclic or periodic remap of data between grids of the same or differing connectivity. The principal design goals for a remap method then consist of total energy conservation, bounded internal energy, and compatibility of kinetic energy and momentum. We also have secondary objectives of limiting velocity and stress in a non-directional manner, keeping primitive variables monotone, and providing a higher than second order reconstruction of remapped variables. In particular, the new contributions fall into three categories associated with: energy conservation and entropy production, reconstruction and bounds preservation of scalar and tensor fields, and conservative remap of nonlinear fields. The paper presents a derivation of the methods, details of implementation, and numerical results for a number of test problems. The methods requires volume integration of polynomial functions in polytopal cells with planar facets, and the requisite expressions are derived for arbitrary order.

An online-coupled NWP/ACT model with conserved Lagrangian levels

NASA Astrophysics Data System (ADS)

Sørensen, B.; Kaas, E.; Lauritzen, P. H.

2012-04-01

Numerical weather and climate modelling is under constant development. Semi-implicit semi-Lagrangian (SISL) models have proven to be numerically efficient in both short-range weather forecasts and climate models, due to the ability to use long time steps. Chemical/aerosol feedback mechanism are becoming more and more relevant in NWP as well as climate models, since the biogenic and anthropogenic emissions can have a direct effect on the dynamics and radiative properties of the atmosphere. To include chemical feedback mechanisms in the NWP models, on-line coupling is crucial. In 3D semi-Lagrangian schemes with quasi-Lagrangian vertical coordinates the Lagrangian levels are remapped to Eulerian model levels each time step. This remapping introduces an undesirable tendency to smooth sharp gradients and creates unphysical numerical diffusion in the vertical distribution. A semi-Lagrangian advection method is introduced, it combines an inherently mass conserving 2D semi-Lagrangian scheme, with a SISL scheme employing both hybrid vertical coordinates and a fully Lagrangian vertical coordinate. This minimizes the vertical diffusion and thus potentially improves the simulation of the vertical profiles of moisture, clouds, and chemical constituents. Since the Lagrangian levels suffer from traditional Lagrangian limitations caused by the convergence and divergence of the flow, remappings to the Eulerian model levels are generally still required - but this need only be applied after a number of time steps - unless dynamic remapping methods are used. For this several different remapping methods has been implemented. The combined scheme is mass conserving, consistent, and multi-tracer efficient.

Compatible, energy conserving, bounds preserving remap of hydrodynamic fields for an extended ALE scheme

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burton, Donald E.; Morgan, Nathaniel Ray; Charest, Marc Robert Joseph

From the very origins of numerical hydrodynamics in the Lagrangian work of von Neumann and Richtmyer [83], the issue of total energy conservation as well as entropy production has been problematic. Because of well known problems with mesh deformation, Lagrangian schemes have evolved into Arbitrary Lagrangian–Eulerian (ALE) methods [39] that combine the best properties of Lagrangian and Eulerian methods. Energy issues have persisted for this class of methods. We believe that fundamental issues of energy conservation and entropy production in ALE require further examination. The context of the paper is an ALE scheme that is extended in the sense thatmore » it permits cyclic or periodic remap of data between grids of the same or differing connectivity. The principal design goals for a remap method then consist of total energy conservation, bounded internal energy, and compatibility of kinetic energy and momentum. We also have secondary objectives of limiting velocity and stress in a non-directional manner, keeping primitive variables monotone, and providing a higher than second order reconstruction of remapped variables. Particularly, the new contributions fall into three categories associated with: energy conservation and entropy production, reconstruction and bounds preservation of scalar and tensor fields, and conservative remap of nonlinear fields. Our paper presents a derivation of the methods, details of implementation, and numerical results for a number of test problems. The methods requires volume integration of polynomial functions in polytopal cells with planar facets, and the requisite expressions are derived for arbitrary order.« less

Reactivation of Rate Remapping in CA3.

PubMed

Schwindel, C Daniela; Navratilova, Zaneta; Ali, Karim; Tatsuno, Masami; McNaughton, Bruce L

2016-09-07

The hippocampus is thought to contribute to episodic memory by creating, storing, and reactivating patterns that are unique to each experience, including different experiences that happen at the same location. Hippocampus can combine spatial and contextual/episodic information using a dual coding scheme known as "global" and "rate" remapping. Global remapping selects which set of neurons can activate at a given location. Rate remapping readjusts the firing rates of this set depending on current experience, thus expressing experience-unique patterns at each location. But can the experience-unique component be retrieved spontaneously? Whereas reactivation of recent, spatially selective patterns in hippocampus is well established, it is never perfect, raising the issue of whether the experiential component might be absent. This question is key to the hypothesis that hippocampus can assist memory consolidation by reactivating and broadcasting experience-specific "index codes" to neocortex. In CA3, global remapping exhibits attractor-like dynamics, whereas rate remapping apparently does not, leading to the hypothesis that only the former can be retrieved associatively and casting doubt on the general consolidation hypothesis. Therefore, we studied whether the rate component is reactivated spontaneously during sleep. We conducted neural ensemble recordings from CA3 while rats ran on a circular track in different directions (in different sessions) and while they slept. It was shown previously that the two directions of running result in strong rate remapping. During sleep, the most recent rate distribution was reactivated preferentially. Therefore, CA3 can retrieve patterns spontaneously that are unique to both the location and the content of recent experience. The hippocampus is required for memory of events and their spatial contexts. The primary correlate of hippocampal activity is location in space, but multiple memories can occur in the same location. To be useful for distinguishing these memories, the hippocampus must be able, not only to express, but also to retrieve both spatial and nonspatial information about events. Whether it can retrieve nonspatial information has been challenged recently. We exposed rats to two different experiences (running in different directions) in the same locations and showed that even the nonspatial components of hippocampal cell firing are reactivated spontaneously during sleep, supporting the conclusion that both types of information about a recent experience can be retrieved. Copyright © 2016 the authors 0270-6474/16/369342-09$15.00/0.

44 CFR 65.14 - Remapping of areas for which local flood protection systems no longer provide base flood protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... local flood protection systems no longer provide base flood protection. 65.14 Section 65.14 Emergency... § 65.14 Remapping of areas for which local flood protection systems no longer provide base flood protection. (a) General. (1) This section describes the procedures to follow and the types of information...

44 CFR 65.14 - Remapping of areas for which local flood protection systems no longer provide base flood protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... local flood protection systems no longer provide base flood protection. 65.14 Section 65.14 Emergency... § 65.14 Remapping of areas for which local flood protection systems no longer provide base flood protection. (a) General. (1) This section describes the procedures to follow and the types of information...

44 CFR 65.14 - Remapping of areas for which local flood protection systems no longer provide base flood protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... local flood protection systems no longer provide base flood protection. 65.14 Section 65.14 Emergency... § 65.14 Remapping of areas for which local flood protection systems no longer provide base flood protection. (a) General. (1) This section describes the procedures to follow and the types of information...

Decoding position, velocity, or goal: does it matter for brain-machine interfaces?

PubMed

Marathe, A R; Taylor, D M

2011-04-01

Arm end-point position, end-point velocity, and the intended final location or 'goal' of a reach have all been decoded from cortical signals for use in brain-machine interface (BMI) applications. These different aspects of arm movement can be decoded from the brain and used directly to control the position, velocity, or movement goal of a device. However, these decoded parameters can also be remapped to control different aspects of movement, such as using the decoded position of the hand to control the velocity of a device. People easily learn to use the position of a joystick to control the velocity of an object in a videogame. Similarly, in BMI systems, the position, velocity, or goal of a movement could be decoded from the brain and remapped to control some other aspect of device movement. This study evaluates how easily people make transformations between position, velocity, and reach goal in BMI systems. It also evaluates how different amounts of decoding error impact on device control with and without these transformations. Results suggest some remapping options can significantly improve BMI control. This study provides guidance on what remapping options to use when various amounts of decoding error are present.

Decoding position, velocity, or goal: Does it matter for brain-machine interfaces?

NASA Astrophysics Data System (ADS)

Marathe, A. R.; Taylor, D. M.

2011-04-01

Arm end-point position, end-point velocity, and the intended final location or 'goal' of a reach have all been decoded from cortical signals for use in brain-machine interface (BMI) applications. These different aspects of arm movement can be decoded from the brain and used directly to control the position, velocity, or movement goal of a device. However, these decoded parameters can also be remapped to control different aspects of movement, such as using the decoded position of the hand to control the velocity of a device. People easily learn to use the position of a joystick to control the velocity of an object in a videogame. Similarly, in BMI systems, the position, velocity, or goal of a movement could be decoded from the brain and remapped to control some other aspect of device movement. This study evaluates how easily people make transformations between position, velocity, and reach goal in BMI systems. It also evaluates how different amounts of decoding error impact on device control with and without these transformations. Results suggest some remapping options can significantly improve BMI control. This study provides guidance on what remapping options to use when various amounts of decoding error are present.

A self-organizing model of perisaccadic visual receptive field dynamics in primate visual and oculomotor system.

PubMed

Mender, Bedeho M W; Stringer, Simon M

2015-01-01

We propose and examine a model for how perisaccadic visual receptive field dynamics, observed in a range of primate brain areas such as LIP, FEF, SC, V3, V3A, V2, and V1, may develop through a biologically plausible process of unsupervised visually guided learning. These dynamics are associated with remapping, which is the phenomenon where receptive fields anticipate the consequences of saccadic eye movements. We find that a neural network model using a local associative synaptic learning rule, when exposed to visual scenes in conjunction with saccades, can account for a range of associated phenomena. In particular, our model demonstrates predictive and pre-saccadic remapping, responsiveness shifts around the time of saccades, and remapping from multiple directions.

A self-organizing model of perisaccadic visual receptive field dynamics in primate visual and oculomotor system

PubMed Central

Mender, Bedeho M. W.; Stringer, Simon M.

2015-01-01

We propose and examine a model for how perisaccadic visual receptive field dynamics, observed in a range of primate brain areas such as LIP, FEF, SC, V3, V3A, V2, and V1, may develop through a biologically plausible process of unsupervised visually guided learning. These dynamics are associated with remapping, which is the phenomenon where receptive fields anticipate the consequences of saccadic eye movements. We find that a neural network model using a local associative synaptic learning rule, when exposed to visual scenes in conjunction with saccades, can account for a range of associated phenomena. In particular, our model demonstrates predictive and pre-saccadic remapping, responsiveness shifts around the time of saccades, and remapping from multiple directions. PMID:25717301

Efficient Load Balancing and Data Remapping for Adaptive Grid Calculations

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Biswas, Rupak

1997-01-01

Mesh adaption is a powerful tool for efficient unstructured- grid computations but causes load imbalance among processors on a parallel machine. We present a novel method to dynamically balance the processor workloads with a global view. This paper presents, for the first time, the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. Previous results indicated that mesh repartitioning and data remapping are potential bottlenecks for performing large-scale scientific calculations. We resolve these issues and demonstrate that our framework remains viable on a large number of processors.

Assessment of genetic diversity among Indian potato (Solanum tuberosum L.) collection using microsatellite and retrotransposon based marker systems.

PubMed

Sharma, Vishakha; Nandineni, Madhusudan R

2014-04-01

Potato (Solanum tuberosum) is an important non-cereal crop throughout the world and is highly recommended for ensuring global food security. Owing to the complexities in genetics and inheritance pattern of potato, the conventional method of cross breeding for developing improved varieties has been difficult. Identification and tagging of desirable traits with informative molecular markers would aid in the development of improved varieties. Insertional polymorphism of copia-like and gypsy-like long terminal repeat retrotransposons (RTN) were investigated among 47 potato varieties from India using Inter-Retrotransposon Amplified Polymorphism (IRAP) and Retrotransposon Microsatellite Amplified Polymorphism (REMAP) marker techniques and were compared with the DNA profiles obtained with simple sequence repeats (SSRs). The genetic polymorphism, efficiency of polymorphism and effectiveness of marker systems were evaluated to assess the extent of genetic diversity among Indian potato varieties. A total of 139 polymorphic SSR alleles, 270 IRAP and 98 REMAP polymorphic bands, showing polymorphism of 100%, 87.9% and 68.5%, respectively, were used for detailed characterization of the genetic relationships among potato varieties by using cluster analysis and principal coordinate analysis (PCoA). IRAP analysis resulted in the highest number of polymorphic bands with an average of 15 polymorphic bands per assay unit when compared to the other two marker systems. Based on pair-wise comparison, the genetic similarity was calculated using Dice similarity coefficient. The SSRs showed a wide range in genetic similarity values (0.485-0.971) as compared to IRAP (0.69-0.911) and REMAP (0.713-0.947). A Mantel's matrix correspondence test showed a high positive correlation (r=0.6) between IRAP and REMAP, an intermediate value (r=0.58) for IRAP and SSR and the lowest value (r=0.17) for SSR and REMAP. Statistically significant cophenetic correlation coefficient values, of 0.961, 0.941 and 0.905 were observed for REMAP, IRAP and SSR, respectively. The widespread presence and distinct DNA profiles for copia-like and gypsy-like RTNs in the examined genotypes indicate that these elements are active in the genome and may have even contributed to the potato genome organization. Although the three marker systems were capable of distinguishing all the 47 varieties; high reproducibility, low cost and ease of DNA profiling data collection make IRAP and REMAP markers highly efficient whole-genome scanning molecular probes for population genetic studies. Information obtained from the present study regarding the genetic association and distinctiveness provides an useful guide for selection of germplasm for plant breeding and conservation efforts. Copyright © 2014. Published by Elsevier Inc.

It "Feels" like It's Me: Interpersonal Multisensory Stimulation Enhances Visual Remapping of Touch from Other to Self

ERIC Educational Resources Information Center

Cardini, Flavia; Tajadura-Jimenez, Ana; Serino, Andrea; Tsakiris, Manos

2013-01-01

Understanding other people's feelings in social interactions depends on the ability to map onto our body the sensory experiences we observed on other people's bodies. It has been shown that the perception of tactile stimuli on the face is improved when concurrently viewing a face being touched. This Visual Remapping of Touch (VRT) is enhanced the…

Redshift remapping and cosmic acceleration in dark-matter-dominated cosmological models

NASA Astrophysics Data System (ADS)

Wojtak, Radosław; Prada, Francisco

2017-10-01

The standard relation between the cosmological redshift and cosmic scalefactor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the Λ cold-dark-matter (ΛCDM) cosmological model. This relation is not a fundamental theory and thus observational determination of this function (redshift remapping) should be regarded as an insightful alternative to holding its standard form in analyses of cosmological data. Here we present non-parametric reconstructions of redshift remapping in dark-matter-dominated models and constraints on cosmological parameters from a joint analysis of all primary cosmological probes including the local measurement of the Hubble constant, Type Ia supernovae, baryon acoustic oscillations (BAO), Planck observations of the cosmic microwave background (CMB) radiation (temperature power spectrum) and cosmic chronometers. The reconstructed redshift remapping points to an additional boost of redshift operating in late epoch of cosmic evolution, but affecting both low-redshift observations and the CMB. The model predicts a significant difference between the actual Hubble constant, h = 0.48 ± 0.02, and its local determination, hobs = 0.73 ± 0.02. The ratio of these two values coincides closely with the maximum expansion rate inside voids formed in the corresponding open cosmological model with Ωm = 0.87 ± 0.03, whereas the actual value of the Hubble constant implies the age of the Universe that is compatible with the Planck ΛCDM cosmology. The model with redshift remapping provides excellent fits to all data and eliminates recently reported tensions between the PlanckΛCDM cosmology, the local determination of the Hubble constant and the BAO measurements from the Ly α forest of high-redshift quasars.

Learning Peri-saccadic Remapping of Receptive Field from Experience in Lateral Intraparietal Area.

PubMed

Wang, Xiao; Wu, Yan; Zhang, Mingsha; Wu, Si

2017-01-01

Our eyes move constantly at a frequency of 3-5 times per second. These movements, called saccades, induce the sweeping of visual images on the retina, yet we perceive the world as stable. It has been suggested that the brain achieves this visual stability via predictive remapping of neuronal receptive field (RF). A recent experimental study disclosed details of this remapping process in the lateral intraparietal area (LIP), that is, about the time of the saccade, the neuronal RF expands along the saccadic trajectory temporally, covering the current RF (CRF), the future RF (FRF), and the region the eye will sweep through during the saccade. A cortical wave (CW) model was also proposed, which attributes the RF remapping as a consequence of neural activity propagating in the cortex, triggered jointly by a visual stimulus and the corollary discharge (CD) signal responsible for the saccade. In this study, we investigate how this CW model is learned naturally from visual experiences at the development of the brain. We build a two-layer network, with one layer consisting of LIP neurons and the other superior colliculus (SC) neurons. Initially, neuronal connections are random and non-selective. A saccade will cause a static visual image to sweep through the retina passively, creating the effect of the visual stimulus moving in the opposite direction of the saccade. According to the spiking-time-dependent-plasticity rule, the connection path in the opposite direction of the saccade between LIP neurons and the connection path from SC to LIP are enhanced. Over many such visual experiences, the CW model is developed, which generates the peri-saccadic RF remapping in LIP as observed in the experiment.

Learning Peri-saccadic Remapping of Receptive Field from Experience in Lateral Intraparietal Area

PubMed Central

Wang, Xiao; Wu, Yan; Zhang, Mingsha; Wu, Si

2017-01-01

Our eyes move constantly at a frequency of 3–5 times per second. These movements, called saccades, induce the sweeping of visual images on the retina, yet we perceive the world as stable. It has been suggested that the brain achieves this visual stability via predictive remapping of neuronal receptive field (RF). A recent experimental study disclosed details of this remapping process in the lateral intraparietal area (LIP), that is, about the time of the saccade, the neuronal RF expands along the saccadic trajectory temporally, covering the current RF (CRF), the future RF (FRF), and the region the eye will sweep through during the saccade. A cortical wave (CW) model was also proposed, which attributes the RF remapping as a consequence of neural activity propagating in the cortex, triggered jointly by a visual stimulus and the corollary discharge (CD) signal responsible for the saccade. In this study, we investigate how this CW model is learned naturally from visual experiences at the development of the brain. We build a two-layer network, with one layer consisting of LIP neurons and the other superior colliculus (SC) neurons. Initially, neuronal connections are random and non-selective. A saccade will cause a static visual image to sweep through the retina passively, creating the effect of the visual stimulus moving in the opposite direction of the saccade. According to the spiking-time-dependent-plasticity rule, the connection path in the opposite direction of the saccade between LIP neurons and the connection path from SC to LIP are enhanced. Over many such visual experiences, the CW model is developed, which generates the peri-saccadic RF remapping in LIP as observed in the experiment. PMID:29249953

Embodying an outgroup: the role of racial bias and the effect of multisensory processing in somatosensory remapping.

PubMed

Fini, Chiara; Cardini, Flavia; Tajadura-Jiménez, Ana; Serino, Andrea; Tsakiris, Manos

2013-01-01

We come to understand other people's physical and mental states by re-mapping their bodily states onto our sensorimotor system. This process, also called somatosensory resonance, is an essential ability for social cognition and is stronger when observing ingroup than outgroup members. Here we investigated, first, whether implicit racial bias constrains somatosensory resonance, and second, whether increasing the ingroup/outgroup perceived physical similarity results in an increase in the somatosensory resonance for outgroup members. We used the Visual Remapping of Touch effect as an index of individuals' ability in resonating with the others, and the Implicit Association Test to measure racial bias. In Experiment 1, participants were asked to detect near-threshold tactile stimuli delivered to their own face while viewing either an ingroup or an outgroup face receiving a similar stimulation. Our results showed that individuals' tactile accuracy when viewing an outgroup face being touched was negatively correlated to their implicit racial bias. In Experiment 2, participants received the interpersonal multisensory stimulation (IMS) while observing an outgroup member. IMS has been found to increase the perceived physical similarity between the observer's and the observed body. We tested whether such increase in ingroup/outgroup perceived physical similarity increased the remapping ability for outgroup members. We found that after sharing IMS experience with an outgroup member, tactile accuracy when viewing touch on outgroup faces increased. Interestingly, participants with stronger implicit bias against the outgroup showed larger positive change in the remapping. We conclude that shared multisensory experiences might represent one key way to improve our ability to resonate with others by overcoming the boundaries between ingroup and outgroup categories.

Redshift remapping and cosmic acceleration in dark-matter-dominated cosmological models

DOE PAGES

Wojtak, Radosław; Prada, Francisco

2017-06-21

The standard relation between the cosmological redshift and cosmic scale factor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the LambdaCDM cosmological model. This relation is not a fundamental theory and thus observational determination of this function (redshift remapping) should be regarded as an insightful alternative to holding its standard form in analyses of cosmological data. We present non-parametric reconstructions of redshift remapping in dark-matter-dominated models and constraints on cosmological parameters from a joint analysis of all primary cosmological probes including the local measurement of the Hubble constant, Type Ia supernovae, baryonic acousticmore » oscillations (BAO), Planck observations of the cosmic microwave background (CMB) radiation (temperature power spectrum) and cosmic chronometers. The reconstructed redshift remapping points to an additional boost of redshift operating in late epoch of cosmic evolution, but affecting both low-redshift observations and the CMB. The model then predicts a significant difference between the actual Hubble constant, h=0.48±0.02, and its local determination, h obs=0.73±0.02. The ratio of these two values coincides closely with the maximum expansion rate inside voids formed in the corresponding open cosmological model with Ω m=0.87±0.03, whereas the actual value of the Hubble constant implies the age of the Universe that is compatible with the Planck LambdaCDM cosmology. The new dark-matter-dominated model with redshift remapping provides excellent fits to all data and eliminates recently reported tensions between the Planck LambdaCDM cosmology, the local determination of the Hubble constant and the BAO measurements from the Ly α forest of high-redshift quasars.« less

Embodying an outgroup: the role of racial bias and the effect of multisensory processing in somatosensory remapping

PubMed Central

Fini, Chiara; Cardini, Flavia; Tajadura-Jiménez, Ana; Serino, Andrea; Tsakiris, Manos

2013-01-01

We come to understand other people's physical and mental states by re-mapping their bodily states onto our sensorimotor system. This process, also called somatosensory resonance, is an essential ability for social cognition and is stronger when observing ingroup than outgroup members. Here we investigated, first, whether implicit racial bias constrains somatosensory resonance, and second, whether increasing the ingroup/outgroup perceived physical similarity results in an increase in the somatosensory resonance for outgroup members. We used the Visual Remapping of Touch effect as an index of individuals' ability in resonating with the others, and the Implicit Association Test to measure racial bias. In Experiment 1, participants were asked to detect near-threshold tactile stimuli delivered to their own face while viewing either an ingroup or an outgroup face receiving a similar stimulation. Our results showed that individuals' tactile accuracy when viewing an outgroup face being touched was negatively correlated to their implicit racial bias. In Experiment 2, participants received the interpersonal multisensory stimulation (IMS) while observing an outgroup member. IMS has been found to increase the perceived physical similarity between the observer's and the observed body. We tested whether such increase in ingroup/outgroup perceived physical similarity increased the remapping ability for outgroup members. We found that after sharing IMS experience with an outgroup member, tactile accuracy when viewing touch on outgroup faces increased. Interestingly, participants with stronger implicit bias against the outgroup showed larger positive change in the remapping. We conclude that shared multisensory experiences might represent one key way to improve our ability to resonate with others by overcoming the boundaries between ingroup and outgroup categories. PMID:24302900

Failure to use corollary discharge to remap visual target locations is associated with psychotic symptom severity in schizophrenia

PubMed Central

Rösler, Lara; Rolfs, Martin; van der Stigchel, Stefan; Neggers, Sebastiaan F. W.; Cahn, Wiepke; Kahn, René S.

2015-01-01

Corollary discharge (CD) refers to “copies” of motor signals sent to sensory areas, allowing prediction of future sensory states. They enable the putative mechanisms supporting the distinction between self-generated and externally generated sensations. Accordingly, many authors have suggested that disturbed CD engenders psychotic symptoms of schizophrenia, which are characterized by agency distortions. CD also supports perceived visual stability across saccadic eye movements and is used to predict the postsaccadic retinal coordinates of visual stimuli, a process called remapping. We tested whether schizophrenia patients (SZP) show remapping disturbances as evidenced by systematic transsaccadic mislocalizations of visual targets. SZP and healthy controls (HC) performed a task in which a saccadic target disappeared upon saccade initiation and, after a brief delay, reappeared at a horizontally displaced position. HC judged the direction of this displacement accurately, despite spatial errors in saccade landing site, indicating that their comparison of the actual to predicted postsaccadic target location relied on accurate CD. SZP performed worse and relied more on saccade landing site as a proxy for the presaccadic target, consistent with disturbed CD. This remapping failure was strongest in patients with more severe psychotic symptoms, consistent with the theoretical link between disturbed CD and phenomenological experiences in schizophrenia. PMID:26108951

Optimizing visual comfort for stereoscopic 3D display based on color-plus-depth signals.

PubMed

Shao, Feng; Jiang, Qiuping; Fu, Randi; Yu, Mei; Jiang, Gangyi

2016-05-30

Visual comfort is a long-facing problem in stereoscopic 3D (S3D) display. In this paper, targeting to produce S3D content based on color-plus-depth signals, a general framework for depth mapping to optimize visual comfort for S3D display is proposed. The main motivation of this work is to remap the depth range of color-plus-depth signals to a new depth range that is suitable to comfortable S3D display. Towards this end, we first remap the depth range globally based on the adjusted zero disparity plane, and then present a two-stage global and local depth optimization solution to solve the visual comfort problem. The remapped depth map is used to generate the S3D output. We demonstrate the power of our approach on perceptually uncomfortable and comfortable stereoscopic images.

Chronic In Vivo Imaging Shows No Evidence of Dendritic Plasticity or Functional Remapping in the Contralesional Cortex after Stroke

PubMed Central

Johnston, David G.; Denizet, Marie; Mostany, Ricardo

2013-01-01

Most stroke survivors exhibit a partial recovery from their deficits. This presumably occurs because of remapping of lost capabilities to functionally related brain areas. Functional brain imaging studies suggest that remapping in the contralateral uninjured cortex might represent a transient stage of compensatory plasticity. Some postmortem studies have also shown that cortical lesions, including stroke, can trigger dendritic plasticity in the contralateral hemisphere, but the data are controversial. We used longitudinal in vivo two-photon microscopy in the contralateral homotopic cortex to record changes in dendritic spines of layer 5 pyramidal neurons in green fluorescent protein mice. We could not detect de novo growth of dendrites or changes in the density or turnover of spines for up to 4 weeks after stroke. We also used intrinsic optical signal imaging to investigate whether the forepaw (FP) sensory representation is remapped to the spared homotopic cortex after stroke. Stimulation of the contralateral FP reliably produced strong intrinsic signals in the spared hemisphere, but we could never detect a signal with ipsilateral FP stimulation after stroke. This lack of contralateral plasticity at the level of apical dendrites of layer 5 pyramidal neurons and FP sensory maps suggests that the contralesional cortex may not contribute to functional recovery after stroke and that, at least in mice, the peri-infarct cortex plays the dominant role in postischemic plasticity. PMID:22499800

Chronic in vivo imaging shows no evidence of dendritic plasticity or functional remapping in the contralesional cortex after stroke.

PubMed

Johnston, David G; Denizet, Marie; Mostany, Ricardo; Portera-Cailliau, Carlos

2013-04-01

Most stroke survivors exhibit a partial recovery from their deficits. This presumably occurs because of remapping of lost capabilities to functionally related brain areas. Functional brain imaging studies suggest that remapping in the contralateral uninjured cortex might represent a transient stage of compensatory plasticity. Some postmortem studies have also shown that cortical lesions, including stroke, can trigger dendritic plasticity in the contralateral hemisphere, but the data are controversial. We used longitudinal in vivo two-photon microscopy in the contralateral homotopic cortex to record changes in dendritic spines of layer 5 pyramidal neurons in green fluorescent protein mice. We could not detect de novo growth of dendrites or changes in the density or turnover of spines for up to 4 weeks after stroke. We also used intrinsic optical signal imaging to investigate whether the forepaw (FP) sensory representation is remapped to the spared homotopic cortex after stroke. Stimulation of the contralateral FP reliably produced strong intrinsic signals in the spared hemisphere, but we could never detect a signal with ipsilateral FP stimulation after stroke. This lack of contralateral plasticity at the level of apical dendrites of layer 5 pyramidal neurons and FP sensory maps suggests that the contralesional cortex may not contribute to functional recovery after stroke and that, at least in mice, the peri-infarct cortex plays the dominant role in postischemic plasticity.

Large-Scale Off-Target Identification Using Fast and Accurate Dual Regularized One-Class Collaborative Filtering and Its Application to Drug Repurposing.

PubMed

Lim, Hansaim; Poleksic, Aleksandar; Yao, Yuan; Tong, Hanghang; He, Di; Zhuang, Luke; Meng, Patrick; Xie, Lei

2016-10-01

Target-based screening is one of the major approaches in drug discovery. Besides the intended target, unexpected drug off-target interactions often occur, and many of them have not been recognized and characterized. The off-target interactions can be responsible for either therapeutic or side effects. Thus, identifying the genome-wide off-targets of lead compounds or existing drugs will be critical for designing effective and safe drugs, and providing new opportunities for drug repurposing. Although many computational methods have been developed to predict drug-target interactions, they are either less accurate than the one that we are proposing here or computationally too intensive, thereby limiting their capability for large-scale off-target identification. In addition, the performances of most machine learning based algorithms have been mainly evaluated to predict off-target interactions in the same gene family for hundreds of chemicals. It is not clear how these algorithms perform in terms of detecting off-targets across gene families on a proteome scale. Here, we are presenting a fast and accurate off-target prediction method, REMAP, which is based on a dual regularized one-class collaborative filtering algorithm, to explore continuous chemical space, protein space, and their interactome on a large scale. When tested in a reliable, extensive, and cross-gene family benchmark, REMAP outperforms the state-of-the-art methods. Furthermore, REMAP is highly scalable. It can screen a dataset of 200 thousands chemicals against 20 thousands proteins within 2 hours. Using the reconstructed genome-wide target profile as the fingerprint of a chemical compound, we predicted that seven FDA-approved drugs can be repurposed as novel anti-cancer therapies. The anti-cancer activity of six of them is supported by experimental evidences. Thus, REMAP is a valuable addition to the existing in silico toolbox for drug target identification, drug repurposing, phenotypic screening, and side effect prediction. The software and benchmark are available at https://github.com/hansaimlim/REMAP.

Large-Scale Off-Target Identification Using Fast and Accurate Dual Regularized One-Class Collaborative Filtering and Its Application to Drug Repurposing

PubMed Central

Poleksic, Aleksandar; Yao, Yuan; Tong, Hanghang; Meng, Patrick; Xie, Lei

2016-01-01

Target-based screening is one of the major approaches in drug discovery. Besides the intended target, unexpected drug off-target interactions often occur, and many of them have not been recognized and characterized. The off-target interactions can be responsible for either therapeutic or side effects. Thus, identifying the genome-wide off-targets of lead compounds or existing drugs will be critical for designing effective and safe drugs, and providing new opportunities for drug repurposing. Although many computational methods have been developed to predict drug-target interactions, they are either less accurate than the one that we are proposing here or computationally too intensive, thereby limiting their capability for large-scale off-target identification. In addition, the performances of most machine learning based algorithms have been mainly evaluated to predict off-target interactions in the same gene family for hundreds of chemicals. It is not clear how these algorithms perform in terms of detecting off-targets across gene families on a proteome scale. Here, we are presenting a fast and accurate off-target prediction method, REMAP, which is based on a dual regularized one-class collaborative filtering algorithm, to explore continuous chemical space, protein space, and their interactome on a large scale. When tested in a reliable, extensive, and cross-gene family benchmark, REMAP outperforms the state-of-the-art methods. Furthermore, REMAP is highly scalable. It can screen a dataset of 200 thousands chemicals against 20 thousands proteins within 2 hours. Using the reconstructed genome-wide target profile as the fingerprint of a chemical compound, we predicted that seven FDA-approved drugs can be repurposed as novel anti-cancer therapies. The anti-cancer activity of six of them is supported by experimental evidences. Thus, REMAP is a valuable addition to the existing in silico toolbox for drug target identification, drug repurposing, phenotypic screening, and side effect prediction. The software and benchmark are available at https://github.com/hansaimlim/REMAP. PMID:27716836

FIRST, a fibered aperture masking instrument: Results of the Lick observing campaign

NASA Astrophysics Data System (ADS)

Bordwell, Baylee; Duchene, Gaspard; Huby, Elsa; Goebel, Sean; Marchis, Franck; Perrin, Guy; Lacour, Sylvestre; Kotani, Takayuki; Gates, Elinor L.; Choquet, Elodie

2015-01-01

FIRST is a prototype instrument aimed at achieving high dynamic range and angular resolution in ground-based images at visible wavelengths near the diffraction limit. FIRST utilizes an aperture masking-like technique that makes use of single-mode fibers and pupil remapping to maximize the area of the telescope mirror in use. While located at Lick observatory in 2011 and 2012, FIRST observed 25 binary systems with the Shane 3m telescope, with separations ranging from 20 to 200 mas, comparable to the 50 mas diffraction limit for our central wavelength. Huby et al. (2013) has reported results for the Capella system that established the utility of FIRST for characterizing stellar binaries using the directly measured spectral flux ratio. Using an improved data analysis pipeline, we obtained closure phase measurements for a majority of the targets observed at Lick, and derived angular separations and spectral flux ratios. From the spectral flux ratios we obtained spectra for the companions over at least 600-850 nm with R~300. Finally, by obtaining results for many binary systems we have better constrained the current performance of FIRST, which has an exciting future ahead at its current location behind SCExAO at the Subaru 8.2 m telescope, where it will eventually become available for general use by the astronomical community.

Spectral dispersion and fringe detection in IOTA

NASA Technical Reports Server (NTRS)

Traub, W. A.; Lacasse, M. G.; Carleton, N. P.

1990-01-01

Pupil plane beam combination, spectral dispersion, detection, and fringe tracking are discussed for the IOTA interferometer. A new spectrometer design is presented in which the angular dispersion with respect to wavenumber is nearly constant. The dispersing element is a type of grism, a series combination of grating and prism, in which the constant parts of the dispersion add, but the slopes cancel. This grism is optimized for the display of channelled spectra. The dispersed fringes can be tracked by a matched-filter photon-counting correlator algorithm. This algorithm requires very few arithmetic operations per detected photon, making it well-suited for real-time fringe tracking. The algorithm is able to adapt to different stellar spectral types, intensity levels, and atmospheric time constants. The results of numerical experiments are reported.

A general higher-order remap algorithm for ALE calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiravalle, Vincent P

2011-01-05

A numerical technique for solving the equations of fluid dynamics with arbitrary mesh motion is presented. The three phases of the Arbitrary Lagrangian Eulerian (ALE) methodology are outlined: the Lagrangian phase, grid relaxation phase and remap phase. The Lagrangian phase follows a well known approach from the HEMP code; in addition the strain rate andflow divergence are calculated in a consistent manner according to Margolin. A donor cell method from the SALE code forms the basis of the remap step, but unlike SALE a higher order correction based on monotone gradients is also added to the remap. Four test problemsmore » were explored to evaluate the fidelity of these numerical techniques, as implemented in a simple test code, written in the C programming language, called Cercion. Novel cell-centered data structures are used in Cercion to reduce the complexity of the programming and maximize the efficiency of memory usage. The locations of the shock and contact discontinuity in the Riemann shock tube problem are well captured. Cercion demonstrates a high degree of symmetry when calculating the Sedov blast wave solution, with a peak density at the shock front that is similar to the value determined by the RAGE code. For a flyer plate test problem both Cercion and FLAG give virtually the same velocity temporal profile at the target-vacuum interface. When calculating a cylindrical implosion of a steel shell, Cercion and FLAG agree well and the Cercion results are insensitive to the use of ALE.« less

Hippocampal Remapping Is Constrained by Sparseness rather than Capacity

PubMed Central

Kammerer, Axel; Leibold, Christian

2014-01-01

Grid cells in the medial entorhinal cortex encode space with firing fields that are arranged on the nodes of spatial hexagonal lattices. Potential candidates to read out the space information of this grid code and to combine it with other sensory cues are hippocampal place cells. In this paper, we investigate a population of grid cells providing feed-forward input to place cells. The capacity of the underlying synaptic transformation is determined by both spatial acuity and the number of different spatial environments that can be represented. The codes for different environments arise from phase shifts of the periodical entorhinal cortex patterns that induce a global remapping of hippocampal place fields, i.e., a new random assignment of place fields for each environment. If only a single environment is encoded, the grid code can be read out at high acuity with only few place cells. A surplus in place cells can be used to store a space code for more environments via remapping. The number of stored environments can be increased even more efficiently by stronger recurrent inhibition and by partitioning the place cell population such that learning affects only a small fraction of them in each environment. We find that the spatial decoding acuity is much more resilient to multiple remappings than the sparseness of the place code. Since the hippocampal place code is sparse, we thus conclude that the projection from grid cells to the place cells is not using its full capacity to transfer space information. Both populations may encode different aspects of space. PMID:25474570

Observed touch on a non-human face is not remapped onto the human observer's own face.

PubMed

Beck, Brianna; Bertini, Caterina; Scarpazza, Cristina; Làdavas, Elisabetta

2013-01-01

Visual remapping of touch (VRT) is a phenomenon in which seeing a human face being touched enhances detection of tactile stimuli on the observer's own face, especially when the observed face expresses fear. This study tested whether VRT would occur when seeing touch on monkey faces and whether it would be similarly modulated by facial expressions. Human participants detected near-threshold tactile stimulation on their own cheeks while watching fearful, happy, and neutral human or monkey faces being concurrently touched or merely approached by fingers. We predicted minimal VRT for neutral and happy monkey faces but greater VRT for fearful monkey faces. The results with human faces replicated previous findings, demonstrating stronger VRT for fearful expressions than for happy or neutral expressions. However, there was no VRT (i.e. no difference between accuracy in touch and no-touch trials) for any of the monkey faces, regardless of facial expression, suggesting that touch on a non-human face is not remapped onto the somatosensory system of the human observer.

Observed Touch on a Non-Human Face Is Not Remapped onto the Human Observer's Own Face

PubMed Central

Beck, Brianna; Bertini, Caterina; Scarpazza, Cristina; Làdavas, Elisabetta

2013-01-01

Visual remapping of touch (VRT) is a phenomenon in which seeing a human face being touched enhances detection of tactile stimuli on the observer's own face, especially when the observed face expresses fear. This study tested whether VRT would occur when seeing touch on monkey faces and whether it would be similarly modulated by facial expressions. Human participants detected near-threshold tactile stimulation on their own cheeks while watching fearful, happy, and neutral human or monkey faces being concurrently touched or merely approached by fingers. We predicted minimal VRT for neutral and happy monkey faces but greater VRT for fearful monkey faces. The results with human faces replicated previous findings, demonstrating stronger VRT for fearful expressions than for happy or neutral expressions. However, there was no VRT (i.e. no difference between accuracy in touch and no-touch trials) for any of the monkey faces, regardless of facial expression, suggesting that touch on a non-human face is not remapped onto the somatosensory system of the human observer. PMID:24250781

Planet detection and spectroscopy in visible light with a single aperture telescope and a nulling coronagraph

NASA Technical Reports Server (NTRS)

Shao, Michael; Serabyn, Eugene; Levine, Bruce Martin; Beichman, Charles; Liu, Duncan; Martin, Stefan; Orton, Glen; Mennesson, Bertrand; Morgan, Rhonda; Velusamy, Thangasamy;

Far field and wavefront characterization of a high-power semiconductor laser for free space optical communications

NASA Technical Reports Server (NTRS)

Cornwell, Donald M., Jr.; Saif, Babak N.

1991-01-01

The spatial pointing angle and far field beamwidth of a high-power semiconductor laser are characterized as a function of CW power and also as a function of temperature. The time-averaged spatial pointing angle and spatial lobe width were measured under intensity-modulated conditions. The measured pointing deviations are determined to be well within the pointing requirements of the NASA Laser Communications Transceiver (LCT) program. A computer-controlled Mach-Zehnder phase-shifter interferometer is used to characterize the wavefront quality of the laser. The rms phase error over the entire pupil was measured as a function of CW output power. Time-averaged measurements of the wavefront quality are also made under intensity-modulated conditions. The measured rms phase errors are determined to be well within the wavefront quality requirements of the LCT program.

Method and apparatus for white-light dispersed-fringe interferometric measurement of corneal topography

NASA Technical Reports Server (NTRS)

Hochberg, Eric B. (Inventor); Baroth, Edmund C. (Inventor)

1994-01-01

An novel interferometric apparatus and method for measuring the topography of aspheric surfaces, without requiring any form of scanning or phase shifting. The apparatus and method of the present invention utilize a white-light interferometer, such as a white-light Twyman-Green interferometer, combined with a means for dispersing a polychromatic interference pattern, using a fiber-optic bundle and a disperser such as a prism for determining the monochromatic spectral intensities of the polychromatic interference pattern which intensities uniquely define the optical path differences or OPD between the surface under test and a reference surface such as a reference sphere. Consequently, the present invention comprises a snapshot approach to measuring aspheric surface topographies such as the human cornea, thereby obviating vibration sensitive scanning which would otherwise reduce the accuracy of the measurement. The invention utilizes a polychromatic interference pattern in the pupil image plane, which is dispersed on a point-wise basis, by using a special area-to-line fiber-optic manifold, onto a CCD or other type detector comprising a plurality of columns of pixels. Each such column is dedicated to a single point of the fringe pattern for enabling determination of the spectral content of the pattern. The auto-correlation of the dispersed spectrum of the fringe pattern is uniquely characteristic of a particular optical path difference between the surface under test and a reference surface.

SACR ADVance 3-D Cartesian Cloud Cover (SACR-ADV-3D3C) product

DOE Data Explorer

Meng Wang, Tami Toto, Eugene Clothiaux, Katia Lamer, Mariko Oue

2017-03-08

SACR-ADV-3D3C remaps the outputs of SACRCORR for cross-wind range-height indicator (CW-RHI) scans to a Cartesian grid and reports reflectivity CFAD and best estimate domain averaged cloud fraction. The final output is a single NetCDF file containing all aforementioned corrected radar moments remapped on a 3-D Cartesian grid, the SACR reflectivity CFAD, a profile of best estimate cloud fraction, a profile of maximum observable x-domain size (xmax), a profile time to horizontal distance estimate and a profile of minimum observable reflectivity (dBZmin).

REDSPEC: NIRSPEC data reduction

NASA Astrophysics Data System (ADS)

Kim, S.; Prato, L.; McLean, I.

2015-07-01

REDSPEC is an IDL based reduction package designed with NIRSPEC in mind though can be used to reduce data from other spectrographs as well. REDSPEC accomplishes spatial rectification by summing an A+B pair of a calibration star to produce an image with two spectra; the image is remapped on the basis of polynomial fits to the spectral traces and calculation of gaussian centroids to define their separation, producing straight spectral traces with respect to the detector rows. The raw images are remapped onto a coordinate system with uniform intervals in spatial extent along the slit and in wavelength along the dispersion axis.

An Attention-Sensitive Memory Trace in Macaque MT Following Saccadic Eye Movements

PubMed Central

Yao, Tao; Treue, Stefan; Krishna, B. Suresh

2016-01-01

We experience a visually stable world despite frequent retinal image displacements induced by eye, head, and body movements. The neural mechanisms underlying this remain unclear. One mechanism that may contribute is transsaccadic remapping, in which the responses of some neurons in various attentional, oculomotor, and visual brain areas appear to anticipate the consequences of saccades. The functional role of transsaccadic remapping is actively debated, and many of its key properties remain unknown. Here, recording from two monkeys trained to make a saccade while directing attention to one of two spatial locations, we show that neurons in the middle temporal area (MT), a key locus in the motion-processing pathway of humans and macaques, show a form of transsaccadic remapping called a memory trace. The memory trace in MT neurons is enhanced by the allocation of top-down spatial attention. Our data provide the first demonstration, to our knowledge, of the influence of top-down attention on the memory trace anywhere in the brain. We find evidence only for a small and transient effect of motion direction on the memory trace (and in only one of two monkeys), arguing against a role for MT in the theoretically critical yet empirically contentious phenomenon of spatiotopic feature-comparison and adaptation transfer across saccades. Our data support the hypothesis that transsaccadic remapping represents the shift of attentional pointers in a retinotopic map, so that relevant locations can be tracked and rapidly processed across saccades. Our results resolve important issues concerning the perisaccadic representation of visual stimuli in the dorsal stream and demonstrate a significant role for top-down attention in modulating this representation. PMID:26901857

Your place or mine: shared sensory experiences elicit a remapping of peripersonal space.

PubMed

Maister, Lara; Cardini, Flavia; Zamariola, Giorgia; Serino, Andrea; Tsakiris, Manos

2015-04-01

Our perceptual systems integrate multisensory information about objects that are close to our bodies, which allow us to respond quickly and appropriately to potential threats, as well as act upon and manipulate useful tools. Intriguingly, the representation of this area close to our body, known as the multisensory 'peripersonal space' (PPS), can expand or contract during social interactions. However, it is not yet known how different social interactions can alter the representation of PPS. In particular, shared sensory experiences, such as those elicited by bodily illusions such as the enfacement illusion, can induce feelings of ownership over the other's body which has also been shown to increase the remapping of the other's sensory experiences onto our own bodies. The current study investigated whether such shared sensory experiences between two people induced by the enfacement illusion could alter the way PPS was represented, and whether this alteration could be best described as an expansion of one's own PPS towards the other or a remapping of the other's PPS onto one's own. An audio-tactile integration task allowed us to measure the extent of the PPS before and after a shared sensory experience with a confederate. Our results showed a clear increase in audio-tactile integration in the space close to the confederate's body after the shared experience. Importantly, this increase did not extend across the space between participant and confederate, as would be expected if the participant's PPS had expanded. Thus, the pattern of results is more consistent with a partial remapping of the confederate's PPS onto the participant's own PPS. These results have important consequences for our understanding of interpersonal space during different kinds of social interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojtak, Radosław; Prada, Francisco

The standard relation between the cosmological redshift and cosmic scale factor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the LambdaCDM cosmological model. This relation is not a fundamental theory and thus observational determination of this function (redshift remapping) should be regarded as an insightful alternative to holding its standard form in analyses of cosmological data. We present non-parametric reconstructions of redshift remapping in dark-matter-dominated models and constraints on cosmological parameters from a joint analysis of all primary cosmological probes including the local measurement of the Hubble constant, Type Ia supernovae, baryonic acousticmore » oscillations (BAO), Planck observations of the cosmic microwave background (CMB) radiation (temperature power spectrum) and cosmic chronometers. The reconstructed redshift remapping points to an additional boost of redshift operating in late epoch of cosmic evolution, but affecting both low-redshift observations and the CMB. The model then predicts a significant difference between the actual Hubble constant, h=0.48±0.02, and its local determination, h obs=0.73±0.02. The ratio of these two values coincides closely with the maximum expansion rate inside voids formed in the corresponding open cosmological model with Ω m=0.87±0.03, whereas the actual value of the Hubble constant implies the age of the Universe that is compatible with the Planck LambdaCDM cosmology. The new dark-matter-dominated model with redshift remapping provides excellent fits to all data and eliminates recently reported tensions between the Planck LambdaCDM cosmology, the local determination of the Hubble constant and the BAO measurements from the Ly α forest of high-redshift quasars.« less

Foreword

NASA Astrophysics Data System (ADS)

Aime, C.; Soummer, R.

This book reports the proceedings of the second Journées d'Imagerie grave{a} Très Haute Dynamique et Détection d'Exoplanètes (Days on High Contrast Imaging and Exoplanets Detection) that were held in Nice in October, 6-10, 2003 with the joint efforts of the Collège de France, the Observatoire de la Côte d'Azur, the CNRS (Centre National de la Recherche Scientifique) and the Laboratoire Universitaire d'Astrophysique de Nice which organized the meeting. The first Journées led to the publication of Volume 8, 2003 EAS Publications Series: Astronomy with High Contrast Imaging: From Planetary Systems to Active Galactic Nuclei that collected 33 papers presented during the session of May, 13-16, 2002. It covered a very large domain of research in high contrast imaging for exoplanet detection: astrophysical science (from protoplanetary disks to AGNs), instruments and techniques (from coronagraphy to nulling), data processing. These Journées took place because of the need of a working session giving enough time to the participants to explain their work and understand that of their colleagues. The second Journées took the form of an École thématique du CNRS. The courses were held in French, but the reports are in English. The present edition reports 29 courses and short presentations given at this occasion. The texts correspond to original presentations, and a few communications, too similar to those of 2002, were not reported here to avoid duplication. This makes the two books complementary. The general theme of the school was similar to that of the former meeting, with a marked teaching objective. The courses and presentations were also more centered in optics and instrumental techniques. The main idea was to study what we could call “exoplanetographs”, instruments using apodisation, coronagraphy, nulling or other techniques to directly record the light of an exoplanet. Fundamental aspects of signal processing were deferred to a third edition of the school. A very short explanation of how the reports are ordered is given here. The Journées of 2003 started with the delocalized lectures (delocalized means here “not in Paris”!) of the Collège de France, of Antoine Labeyrie who wrote a report on Removal of coronagraphy residues with an adaptive hologram. Three invited seminars follow: Olivier Guyon (Pupil remapping techniques), Daniel Rouan (Ultra-nulling interferometers), and Kjetil Dohlen (Phase masks in astronomy). An illustration from Daniel Rouan's talk on the properties of Prouhet-Thué-Morse series was also selected for the cover figure of this edition. These papers are followed by the courses and communications given during the 4 days of the school, in a slightly different order of their presentation. The first two days were on atmospheric turbulence and adaptive optics for coronagraphy, and also coronagraphic space projects. Steve Ridgway gives a general introduction to the problem (Astronomy with high contrast imaging). This is followed by a presentation on Fourier and Statistical Optics: Shaped and Apodized apertures (Claude Aime), The effect of a coronagraph on the statistics of adaptive optics pinned speckles (Claude Aime and Rémi Soummer). A general introduction to the problem of atmospheric turbulence is made by Julien Borgnino. A presentation of the Concordia site with emphasis on its advantages for high contrast imaging is given by Eric Fossat. Several presentations relative to numerical simulations of Adaptive Optics and coronagraphy follow: Marcel Carbillet (AO for very high contrast imaging), Lyu Abe and Anthony Boccaletti share two presentations on Numerical simulations for coronagraphy. These presentations are followed by reports on experiments: Sandrine Thomas (SAM-the SOAR adaptive module), Pierre Baudoz (Cryogenic IR test of the 4QPM coronagraph), Anthony Boccaletti (Coronagraphy with JWST in the thermal IR). Pierre Bourget (Hg-Mask Coronagraph) ends this part with a coronagraph using a mercury drop as a Lyot mask. The next session focused on nulling interferometry and we gather here the corresponding contribution. Two complementary reports on theory and experiment of Bracewell interferometry were made by Yves Rabbia (Theoretical aspects of Darwin) and Marc Ollivier (Experimental aspects of Darwin). Olivier Absil gave a report on the ground based nulling interferometer experiment (Effects of atmospheric turbulence on GENIE) and Valérie Weber on MAII (Nulling interferometric broadbord). A comparison between nulling and different classes of coronagraphs was made by Olivier Guyon (Coronagraphy vs. nulling). A few prospective papers have been regrouped at the end of the book: Interferometric remapped array nulling (Lyu Abe), Multiple-stage apodized Lyot coronagraph (Claude Aime and Rémi Soummer), Piston sensor using dispersed speckles (Virginie Borkowski), Principle of a coaxial achromatic interfero coronagraph (Jean Gay), Coronagraphic imaging on the VLTI with VIDA (Olivier Lardière), Phase contrast apodisation (Frantz Martinache) The last section regroups science aspects and results on sky, using high contrast imaging: Low mass companions searches using high dynamic range imaging (Jean-Luc Beuzit). The last paper by Claire Moutou (Ground-based direct imaging of exoplanets) can be read as a prospective conclusion of the Journées. C. Aime and R. Soummer

Maxis-A rezoning and remapping code in two dimensional cylindrical geometry

NASA Astrophysics Data System (ADS)

Lin, Zhiwei; Jiang, Shaoen; Zhang, Lu; Kuang, Longyu; Li, Hang

2018-06-01

This paper presents the new version of our code Maxis (Lin et al., 2011). Maxis is a local rezoning and remapping code in two dimensional cylindrical geometry, which can be employed to address the grid distortion problem of unstructured meshes. The new version of Maxis is mostly programmed in the C language which considerably improves its computational efficiency with respect to the former Matlab version. A new algorithm for determining the intersection of two arbitrary convex polygons is also incorporated into the new version. Some additional linking functions are further provided in the new version for the purpose of combining Maxis and MULTI2D.

Tempest: Tools for Addressing the Needs of Next-Generation Climate Models

NASA Astrophysics Data System (ADS)

Ullrich, P. A.; Guerra, J. E.; Pinheiro, M. C.; Fong, J.

2015-12-01

Tempest is a comprehensive simulation-to-science infrastructure that tackles the needs of next-generation, high-resolution, data intensive climate modeling activities. This project incorporates three key components: TempestDynamics, a global modeling framework for experimental numerical methods and high-performance computing; TempestRemap, a toolset for arbitrary-order conservative and consistent remapping between unstructured grids; and TempestExtremes, a suite of detection and characterization tools for identifying weather extremes in large climate datasets. In this presentation, the latest advances with the implementation of this framework will be discussed, and a number of projects now utilizing these tools will be featured.

Perceptual evaluation of color transformed multispectral imagery

NASA Astrophysics Data System (ADS)

Toet, Alexander; de Jong, Michael J.; Hogervorst, Maarten A.; Hooge, Ignace T. C.

2014-04-01

Color remapping can give multispectral imagery a realistic appearance. We assessed the practical value of this technique in two observer experiments using monochrome intensified (II) and long-wave infrared (IR) imagery, and color daylight (REF) and fused multispectral (CF) imagery. First, we investigated the amount of detail observers perceive in a short timespan. REF and CF imagery yielded the highest precision and recall measures, while II and IR imagery yielded significantly lower values. This suggests that observers have more difficulty in extracting information from monochrome than from color imagery. Next, we measured eye fixations during free image exploration. Although the overall fixation behavior was similar across image modalities, the order in which certain details were fixated varied. Persons and vehicles were typically fixated first in REF, CF, and IR imagery, while they were fixated later in II imagery. In some cases, color remapping II imagery and fusion with IR imagery restored the fixation order of these image details. We conclude that color remapping can yield enhanced scene perception compared to conventional monochrome nighttime imagery, and may be deployed to tune multispectral image representations such that the resulting fixation behavior resembles the fixation behavior corresponding to daylight color imagery.

Relocating cued goals induces population remapping in CA1 related to memory performance in a two-platform water task in rats.

PubMed

Lee, Justin Quinn; LeDuke, Deryn O; Chua, Kate; McDonald, Robert J; Sutherland, Robert J

2018-06-01

The activity of CA1 neurons in the rodent hippocampus represents multiple aspects of learning episodes, including cue and place information. Previous reports on cue and place representation in CA1 have examined activity in single neurons and population recordings during free exploration of an environment or when actions are directed to either cue or place aspects of memory tasks. To better understand cue and place memory representation in CA1, and how these interact during goal-directed navigation, we investigated population activity in CA1 during memory encoding and retrieval in a novel water task with two visibly distinct platforms, using mRNA for immediate early genes Arc and Homer1a as markers of neural activity. After training, relocating cues to new places induces an extensive, perhaps global, remapping of the memory code that is accompanied by altered navigation and rapid learning of new cue-place information. In addition, we have found a significant relationship between the extent of reactivation and overall cue choice accuracy. These findings demonstrate an important relationship between population remapping in CA1 and memory-guided behavior. © 2018 Wiley Periodicals, Inc.

A conceptual scheme for cophasing across gaps in segmented pupils with a laser guide star Fizeau interferometer

NASA Astrophysics Data System (ADS)

Tuthill, Peter

2016-08-01

Finding and maintaining an accurate cophasing solution for the large primary mirrors which comprise the coming generation of Extremely Large Telescopes has required a significant technological development effort that is still ongoing. Mirrors based on an assembly of a few large segments, such as the Giant Magellan Telescope (GMT - under construction) and the Large Binocular Telescope (LBT - operational) face a particular challenge: elements must be cophased across a gaps ranging from tens of centimeters to meters. Although it is widely believed that laser guide stars are not useful for this specific application, this paper advances a new concept that challenges this orthodoxy. By projecting a Fizeau interference pattern into the sky, and analyzing the form of the backscattered image, it is shown that at least in principle it is possible to cophase across arbitrary gaps.

Spatial updating in area LIP is independent of saccade direction.

PubMed

Heiser, Laura M; Colby, Carol L

2006-05-01

We explore the world around us by making rapid eye movements to objects of interest. Remarkably, these eye movements go unnoticed, and we perceive the world as stable. Spatial updating is one of the neural mechanisms that contributes to this perception of spatial constancy. Previous studies in macaque lateral intraparietal cortex (area LIP) have shown that individual neurons update, or "remap," the locations of salient visual stimuli at the time of an eye movement. The existence of remapping implies that neurons have access to visual information from regions far beyond the classically defined receptive field. We hypothesized that neurons have access to information located anywhere in the visual field. We tested this by recording the activity of LIP neurons while systematically varying the direction in which a stimulus location must be updated. Our primary finding is that individual neurons remap stimulus traces in multiple directions, indicating that LIP neurons have access to information throughout the visual field. At the population level, stimulus traces are updated in conjunction with all saccade directions, even when we consider direction as a function of receptive field location. These results show that spatial updating in LIP is effectively independent of saccade direction. Our findings support the hypothesis that the activity of LIP neurons contributes to the maintenance of spatial constancy throughout the visual field.

HEVC for high dynamic range services

NASA Astrophysics Data System (ADS)

Kim, Seung-Hwan; Zhao, Jie; Misra, Kiran; Segall, Andrew

2015-09-01

Displays capable of showing a greater range of luminance values can render content containing high dynamic range information in a way such that the viewers have a more immersive experience. This paper introduces the design aspects of a high dynamic range (HDR) system, and examines the performance of the HDR processing chain in terms of compression efficiency. Specifically it examines the relation between recently introduced Society of Motion Picture and Television Engineers (SMPTE) ST 2084 transfer function and the High Efficiency Video Coding (HEVC) standard. SMPTE ST 2084 is designed to cover the full range of an HDR signal from 0 to 10,000 nits, however in many situations the valid signal range of actual video might be smaller than SMPTE ST 2084 supported range. The above restricted signal range results in restricted range of code values for input video data and adversely impacts compression efficiency. In this paper, we propose a code value remapping method that extends the restricted range code values into the full range code values so that the existing standards such as HEVC may better compress the video content. The paper also identifies related non-normative encoder-only changes that are required for remapping method for a fair comparison with anchor. Results are presented comparing the efficiency of the current approach versus the proposed remapping method for HM-16.2.

Hippocampal place-cell firing during movement in three-dimensional space

NASA Technical Reports Server (NTRS)

Knierim, J. J.; McNaughton, B. L.

2001-01-01

"Place" cells of the rat hippocampus are coupled to "head direction" cells of the thalamus and limbic cortex. Head direction cells are sensitive to head direction in the horizontal plane only, which leads to the question of whether place cells similarly encode locations in the horizontal plane only, ignoring the z axis, or whether they encode locations in three dimensions. This question was addressed by recording from ensembles of CA1 pyramidal cells while rats traversed a rectangular track that could be tilted and rotated to different three-dimensional orientations. Cells were analyzed to determine whether their firing was bound to the external, three-dimensional cues of the environment, to the two-dimensional rectangular surface, or to some combination of these cues. Tilting the track 45 degrees generally provoked a partial remapping of the rectangular surface in that some cells maintained their place fields, whereas other cells either gained new place fields, lost existing fields, or changed their firing locations arbitrarily. When the tilted track was rotated relative to the distal landmarks, most place fields remapped, but a number of cells maintained the same place field relative to the x-y coordinate frame of the laboratory, ignoring the z axis. No more cells were bound to the local reference frame of the recording apparatus than would be predicted by chance. The partial remapping demonstrated that the place cell system was sensitive to the three-dimensional manipulations of the recording apparatus. Nonetheless the results were not consistent with an explicit three-dimensional tuning of individual hippocampal neurons nor were they consistent with a model in which different sets of cells are tightly coupled to different sets of environmental cues. The results are most consistent with the statement that hippocampal neurons can change their "tuning functions" in arbitrary ways when features of the sensory input or behavioral context are altered. Understanding the rules that govern the remapping phenomenon holds promise for deciphering the neural circuitry underlying hippocampal function.

Social and novel contexts modify hippocampal CA2 representations of space

PubMed Central

Alexander, Georgia M.; Farris, Shannon; Pirone, Jason R.; Zheng, Chenguang; Colgin, Laura L.; Dudek, Serena M.

2016-01-01

The hippocampus supports a cognitive map of space and is critical for encoding declarative memory (who, what, when and where). Recent studies have implicated hippocampal subfield CA2 in social and contextual memory but how it does so remains unknown. Here we find that in adult male rats, presentation of a social stimulus (novel or familiar rat) or a novel object induces global remapping of place fields in CA2 with no effect on neuronal firing rate or immediate early gene expression. This remapping did not occur in CA1, suggesting this effect is specific for CA2. Thus, modification of existing spatial representations might be a potential mechanism by which CA2 encodes social and novel contextual information. PMID:26806606

Evaluating Remapped Physical Reach for Hand Interactions with Passive Haptics in Virtual Reality.

PubMed

Han, Dustin T; Suhail, Mohamed; Ragan, Eric D

2018-04-01

Virtual reality often uses motion tracking to incorporate physical hand movements into interaction techniques for selection and manipulation of virtual objects. To increase realism and allow direct hand interaction, real-world physical objects can be aligned with virtual objects to provide tactile feedback and physical grasping. However, unless a physical space is custom configured to match a specific virtual reality experience, the ability to perfectly match the physical and virtual objects is limited. Our research addresses this challenge by studying methods that allow one physical object to be mapped to multiple virtual objects that can exist at different virtual locations in an egocentric reference frame. We study two such techniques: one that introduces a static translational offset between the virtual and physical hand before a reaching action, and one that dynamically interpolates the position of the virtual hand during a reaching motion. We conducted two experiments to assess how the two methods affect reaching effectiveness, comfort, and ability to adapt to the remapping techniques when reaching for objects with different types of mismatches between physical and virtual locations. We also present a case study to demonstrate how the hand remapping techniques could be used in an immersive game application to support realistic hand interaction while optimizing usability. Overall, the translational technique performed better than the interpolated reach technique and was more robust for situations with larger mismatches between virtual and physical objects.

One-shot phase-shifting phase-grating interferometry with modulation of polarization: case of four interferograms.

PubMed

Rodriguez-Zurita, Gustavo; Meneses-Fabian, Cruz; Toto-Arellano, Noel-Ivan; Vázquez-Castillo, José F; Robledo-Sánchez, Carlos

2008-05-26

An experimental setup for optical phase extraction from 2-D interferograms using a one-shot phase-shifting technique able to achieve four interferograms with 90 degrees phase shifts in between is presented. The system uses a common-path interferometer consisting of two windows in the input plane and a phase grating in Fourier plane as its pupil. Each window has a birefringent wave plate attached in order to achieve nearly circular polarization of opposite rotations one respect to the other after being illuminated with a 45 degrees linear polarized beam. In the output, interference of the fields associated with replicated windows (diffraction orders) is achieved by a proper choice of the windows spacing with respect to the grating period. The phase shifts to achieve four interferograms simultaneously to perform phase-shifting interferometry can be obtained by placing linear polarizers on each diffraction orders before detection at an appropriate angle. Some experimental results are shown.

Parallel DSMC Solution of Three-Dimensional Flow Over a Finite Flat Plate

NASA Technical Reports Server (NTRS)

Nance, Robert P.; Wilmoth, Richard G.; Moon, Bongki; Hassan, H. A.; Saltz, Joel

1994-01-01

This paper describes a parallel implementation of the direct simulation Monte Carlo (DSMC) method. Runtime library support is used for scheduling and execution of communication between nodes, and domain decomposition is performed dynamically to maintain a good load balance. Performance tests are conducted using the code to evaluate various remapping and remapping-interval policies, and it is shown that a one-dimensional chain-partitioning method works best for the problems considered. The parallel code is then used to simulate the Mach 20 nitrogen flow over a finite-thickness flat plate. It is shown that the parallel algorithm produces results which compare well with experimental data. Moreover, it yields significantly faster execution times than the scalar code, as well as very good load-balance characteristics.

Enhanced canopy fuel mapping by integrating lidar data

USGS Publications Warehouse

Peterson, Birgit E.; Nelson, Kurtis J.

2016-10-03

BackgroundThe Wildfire Sciences Team at the U.S. Geological Survey’s Earth Resources Observation and Science Center produces vegetation type, vegetation structure, and fuel products for the United States, primarily through the Landscape Fire and Resource Management Planning Tools (LANDFIRE) program. LANDFIRE products are used across disciplines for a variety of applications. The LANDFIRE data retain their currency and relevancy through periodic updating or remapping. These updating and remapping efforts provide opportunities to improve the LANDFIRE product suite by incorporating data from other sources. Light detection and ranging (lidar) is uniquely suitable for gathering information on vegetation structure and spatial arrangement because it can collect data in three dimensions. The Wildfire Sciences Team has several completed and ongoing studies focused on integrating lidar into vegetation and fuels mapping.

Stroboscopic Interferometer for Measuring Mirror Vibrations

NASA Technical Reports Server (NTRS)

Stahl, H. Philip; Robers, Ted

2005-01-01

Stroboscopic interferometry is a technique for measuring the modes of vibration of mirrors that are lightweight and, therefore, unavoidably flexible. The technique was conceived especially for modal characterization of lightweight focusing mirror segments to be deployed in outer space; however, the technique can be applied to lightweight mirrors designed for use on Earth as well as the modal investigation of other optical and mechanical structures. To determine the modal structure of vibration of a mirror, it is necessary to excite the mirror by applying a force that varies periodically with time at a controllable frequency. The excitation can utilize sinusoidal, square, triangular, or even asynchronous waveforms. Because vibrational modes occur at specific resonant frequencies, it is necessary to perform synchronous measurements and sweep the frequency to locate the significant resonant modes. For a given mode it is possible to step the phase of data acquisition in order to capture the modal behavior over a single cycle of the resonant frequency. In order to measure interferometrically the vibrational response of the mirror at a given frequency, an interferometer must be suitably aligned with the mirror and adjustably phase-locked with the excitation signal. As in conventional stroboscopic photography, the basic idea in stroboscopic interferometry is to capture an image of the shape of a moving object (in this case, the vibrating mirror) at a specified instant of time in the vibration cycle. Adjusting the phase difference over a full cycle causes the interference fringes to vary over the full range of motion for the mode at the excitation frequency. The interference-fringe pattern is recorded as a function of the phase difference, and, from the resulting data, the surface shape of the mirror for the given mode is extracted. In addition to the interferometer and the mirror to be tested, the equipment needed for stroboscopic interferometry includes an arbitrary-function generator (that is, a signal generator), an oscilloscope, a trigger filter, and an advanced charge-coupled-device (CCD) camera. The optical components are positioned to form a pupil image of the mirror under test on the CCD chip, so that the interference pattern representative of the instantaneous mirror shape is imaged on the CCD chip.

Postprocessing classification images

NASA Technical Reports Server (NTRS)

Kan, E. P.

1979-01-01

Program cleans up remote-sensing maps. It can be used with existing image-processing software. Remapped images closely resemble familiar resource information maps and can replace or supplement classification images not postprocessed by this program.

Redundant Remapping Reform Act of 2011

THOMAS, 112th Congress

Sen. Moran, Jerry [R-KS

2011-12-16

Senate - 12/16/2011 Read twice and referred to the Committee on Banking, Housing, and Urban Affairs. (All Actions) Tracker: This bill has the status IntroducedHere are the steps for Status of Legislation:

Remapping of border ownership in the visual cortex.

PubMed

O'Herron, Philip; von der Heydt, Rüdiger

2013-01-30

We see objects as having continuity although the retinal image changes frequently. How such continuity is achieved is hard to understand, because neurons in the visual cortex have small receptive fields that are fixed on the retina, which means that a different set of neurons is activated every time the eyes move. Neurons in areas V1 and V2 of the visual cortex signal the local features that are currently in their receptive fields and do not show "remapping" when the image moves. However, subsets of neurons in these areas also carry information about global aspects, such as figure-ground organization. Here we performed experiments to find out whether figure-ground organization is remapped. We recorded single neurons in macaque V1 and V2 in which figure-ground organization is represented by assignment of contours to regions (border ownership). We found previously that border-ownership signals persist when a figure edge is switched to an ambiguous edge by removing the context. We now used this paradigm to see whether border ownership transfers when the ambiguous edge is moved across the retina. In the new position, the edge activated a different set of neurons at a different location in cortex. We found that border ownership was transferred to the newly activated neurons. The transfer occurred whether the edge was moved by a saccade or by moving the visual display. Thus, although the contours are coded in retinal coordinates, their assignment to objects is maintained across movements of the retinal image.

A robust and efficient polyhedron subdivision and intersection algorithm for three-dimensional MMALE remapping

NASA Astrophysics Data System (ADS)

Chen, Xiang; Zhang, Xiong; Jia, Zupeng

2017-06-01

The Multi-Material Arbitrary Lagrangian Eulerian (MMALE) method is an effective way to simulate the multi-material flow with severe surface deformation. Comparing with the traditional Arbitrary Lagrangian Eulerian (ALE) method, the MMALE method allows for multiple materials in a single cell which overcomes the difficulties in grid refinement process. In recent decades, many researches have been conducted for the Lagrangian, rezoning and surface reconstruction phases, but less attention has been paid to the multi-material remapping phase especially for the three-dimensional problems due to two complex geometric problems: the polyhedron subdivision and the polyhedron intersection. In this paper, we propose a ;Clipping and Projecting; algorithm for polyhedron intersection whose basic idea comes from the commonly used method by Grandy (1999) [29] and Jia et al. (2013) [34]. Our new algorithm solves the geometric problem by an incremental modification of the topology based on segment-plane intersections. A comparison with Jia et al. (2013) [34] shows our new method improves the efficiency by 55% to 65% when calculating polyhedron intersections. Moreover, the instability caused by the geometric degeneracy can be thoroughly avoided because the geometry integrity is preserved in the new algorithm. We also focus on the polyhedron subdivision process and describe an algorithm which could automatically and precisely tackle the various situations including convex, non-convex and multiple subdivisions. Numerical studies indicate that by using our polyhedron subdivision and intersection algorithm, the volume conversation of the remapping phase can be exactly preserved in the MMALE simulation.

LANDFIRE 2015 Remap – Utilization of Remotely Sensed Data to Classify Existing Vegetation Type and Structure to Support Strategic Planning and Tactical Response

USGS Publications Warehouse

Picotte, Joshua J.; Long, Jordan; Peterson, Birgit; Nelson, Kurtis

2017-01-01

The LANDFIRE Program produces national scale vegetation, fuels, fire regimes, and landscape disturbance data for the entire U.S. These data products have been used to model the potential impacts of fire on the landscape [1], the wildfire risks associated with land and resource management [2, 3], and those near population centers and accompanying Wildland Urban Interface zones [4], as well as many other applications. The initial LANDFIRE National Existing Vegetation Type (EVT) and vegetation structure layers, including vegetation percent cover and height, were mapped circa 2001 and released in 2009 [5]. Each EVT is representative of the dominant plant community within a given area. The EVT layer has since been updated by identifying areas of landscape change and modifying the vegetation types utilizing a series of rules that consider the disturbance type, severity of disturbance, and time since disturbance [6, 7]. Non-disturbed areas were adjusted for vegetation growth and succession. LANDFIRE vegetation structure layers also have been updated by using data modeling techniques [see 6 for a full description]. The subsequent updated versions of LANDFIRE include LANDFIRE 2008, 2010, 2012, and LANDFIRE 2014 is being incrementally released, with all data being released in early 2017. Additionally, a comprehensive remap of the baseline data, LANDFIRE 2015 Remap, is being prototyped, and production is tentatively planned to begin in early 2017 to provide a more current baseline for future updates.

Photogrammetric aspects of remapping procedures

NASA Technical Reports Server (NTRS)

Mikhail, E. M.

1982-01-01

Photogrammetric control generation is discussed. Techniques in remote sensing data reduction are described. Emphasis is placed on methods of rectification of aerial photography and frame photography. Examples of multispectral band scanner data that were processed are presented.

REGIONAL EMAP PROPOSALS

EPA Science Inventory

The US EPA's Environmental Assessment and Monitoring Program (EMAP) annually funds regional EMAP (REMAP) projects through each of the regions to support the improvement of monitoring activities by the states. The last call for proposals emphasized the need to support biological m...

Contextual remapping in visual search after predictable target-location changes.

PubMed

Conci, Markus; Sun, Luning; Müller, Hermann J

2011-07-01

Invariant spatial context can facilitate visual search. For instance, detection of a target is faster if it is presented within a repeatedly encountered, as compared to a novel, layout of nontargets, demonstrating a role of contextual learning for attentional guidance ('contextual cueing'). Here, we investigated how context-based learning adapts to target location (and identity) changes. Three experiments were performed in which, in an initial learning phase, observers learned to associate a given context with a given target location. A subsequent test phase then introduced identity and/or location changes to the target. The results showed that contextual cueing could not compensate for target changes that were not 'predictable' (i.e. learnable). However, for predictable changes, contextual cueing remained effective even immediately after the change. These findings demonstrate that contextual cueing is adaptive to predictable target location changes. Under these conditions, learned contextual associations can be effectively 'remapped' to accommodate new task requirements.

Change of reference frame for tactile localization during child development.

PubMed

Pagel, Birthe; Heed, Tobias; Röder, Brigitte

2009-11-01

Temporal order judgements (TOJ) for two tactile stimuli, one presented to the left and one to the right hand, are less precise when the hands are crossed over the midline than when the hands are uncrossed. This 'crossed hand' effect has been considered as evidence for a remapping of tactile input into an external reference frame. Since late, but not early, blind individuals show such remapping, it has been hypothesized that the use of an external reference frame develops during childhood. Five- to 10-year-old children were therefore tested with the tactile TOJ task, both with uncrossed and crossed hands. Overall performance in the TOJ task improved with age. While children older than 5 1/2 years displayed a crossed hand effect, younger children did not. Therefore the use of an external reference frame for tactile, and possibly multisensory, localization seems to be acquired at age 5.

Impaired hippocampal rate coding after lesions of the lateral entorhinal cortex.

PubMed

Lu, Li; Leutgeb, Jill K; Tsao, Albert; Henriksen, Espen J; Leutgeb, Stefan; Barnes, Carol A; Witter, Menno P; Moser, May-Britt; Moser, Edvard I

2013-08-01

In the hippocampus, spatial and non-spatial parameters may be represented by a dual coding scheme, in which coordinates in space are expressed by the collective firing locations of place cells and the diversity of experience at these locations is encoded by orthogonal variations in firing rates. Although the spatial signal may reflect input from medial entorhinal cortex, the sources of the variations in firing rate have not been identified. We found that rate variations in rat CA3 place cells depended on inputs from the lateral entorhinal cortex (LEC). Hippocampal rate remapping, induced by changing the shape or the color configuration of the environment, was impaired by lesions in those parts of the ipsilateral LEC that provided the densest input to the hippocampal recording position. Rate remapping was not observed in LEC itself. The findings suggest that LEC inputs are important for efficient rate coding in the hippocampus.

Perisaccadic Receptive Field Expansion in the Lateral Intraparietal Area.

PubMed

Wang, Xiaolan; Fung, C C Alan; Guan, Shaobo; Wu, Si; Goldberg, Michael E; Zhang, Mingsha

2016-04-20

Humans and monkeys have access to an accurate representation of visual space despite a constantly moving eye. One mechanism by which the brain accomplishes this is by remapping visual receptive fields around the time of a saccade. In this process a neuron can be excited by a probe stimulus in the current receptive field, and also simultaneously by a probe stimulus in the location that will be brought into the neuron's receptive field by the saccade (the future receptive field), even before saccade begins. Here we show that perisaccadic neuronal excitability is not limited to the current and future receptive fields but encompasses the entire region of visual space across which the current receptive field will be swept by the saccade. A computational model shows that this receptive field expansion is consistent with the propagation of a wave of activity across the cerebral cortex as saccade planning and remapping proceed. Copyright © 2016 Elsevier Inc. All rights reserved.

PLUM: Parallel Load Balancing for Adaptive Unstructured Meshes

NASA Technical Reports Server (NTRS)

Oliker, Leonid; Biswas, Rupak; Saini, Subhash (Technical Monitor)

1998-01-01

Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. We present a novel method called PLUM to dynamically balance the processor workloads with a global view. This paper presents the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. A data redistribution model is also presented that predicts the remapping cost on the SP2. This model is required to determine whether the gain from a balanced workload distribution offsets the cost of data movement. Results presented in this paper demonstrate that PLUM is an effective dynamic load balancing strategy which remains viable on a large number of processors.

Noiseless Vlasov-Poisson simulations with linearly transformed particles

DOE PAGES

Pinto, Martin C.; Sonnendrucker, Eric; Friedman, Alex; ...

2014-06-25

We introduce a deterministic discrete-particle simulation approach, the Linearly-Transformed Particle-In-Cell (LTPIC) method, that employs linear deformations of the particles to reduce the noise traditionally associated with particle schemes. Formally, transforming the particles is justified by local first order expansions of the characteristic flow in phase space. In practice the method amounts of using deformation matrices within the particle shape functions; these matrices are updated via local evaluations of the forward numerical flow. Because it is necessary to periodically remap the particles on a regular grid to avoid excessively deforming their shapes, the method can be seen as a development ofmore » Denavit's Forward Semi-Lagrangian (FSL) scheme (Denavit, 1972 [8]). However, it has recently been established (Campos Pinto, 2012 [20]) that the underlying Linearly-Transformed Particle scheme converges for abstract transport problems, with no need to remap the particles; deforming the particles can thus be seen as a way to significantly lower the remapping frequency needed in the FSL schemes, and hence the associated numerical diffusion. To couple the method with electrostatic field solvers, two specific charge deposition schemes are examined, and their performance compared with that of the standard deposition method. Finally, numerical 1d1v simulations involving benchmark test cases and halo formation in an initially mismatched thermal sheet beam demonstrate some advantages of our LTPIC scheme over the classical PIC and FSL methods. Lastly, benchmarked test cases also indicate that, for numerical choices involving similar computational effort, the LTPIC method is capable of accuracy comparable to or exceeding that of state-of-the-art, high-resolution Vlasov schemes.« less

Geologic Map of the San Luis Hills Area, Conejos and Costilla Counties, Colorado

USGS Publications Warehouse

Thompson, Ren A.; Machette, Michael N.

1989-01-01

This report is a digital image of the U.S. Geological Survey Miscellaneous Investigations Series Map I-1906, 'Geologic map of the San Luis Hills area, Conejos and Costilla Counties, Colorado,' which was published in 1989 by Thompson and Machette, scale 1:50,000 but has been unavailable in a digital version. The map area represents the southwestern portion of the Alamosa 30' x 60' quadrangle, which is currently being remapped by the U.S. Geological Survey. The northern and eastern margins of the San Luis Hills area have been remapped at greater detail and thus small portions of the map area have been updated. The northern margin is shown on U.S. Geological Survey Open-File Report 2005-1392, the northeastern portion is shown on U.S. Geological Survey Open-File Report 2008-1124, and the eastern margin is shown on U.S. Geological Survey Open-File Report 2007-1074. The most significant changes to the 1989 map area are recognition of Lake Alamosa and its deposits (Alamosa Formation), remapping of bedrock in the northeastern San Luis Hills, and redating of volcanic units in the San Luis Hills. Although unpublished, new 40Ar/39Ar ages for volcanic units in the Conejos and Hinsdale Formations add precision to the previous K/Ar-dated rocks, but do not change the basic chronology of the units. The digital version of this map was prepared by Theodore R. Brandt by scanning the original map at 300 pixels per inch, prior to creating the press-quality (96 Mb) and standard (5 Mb) .pdf files.

Scalable Failure Masking for Stencil Computations using Ghost Region Expansion and Cell to Rank Remapping

DOE PAGES

Gamell, Marc; Teranishi, Keita; Kolla, Hemanth; ...

2017-10-26

In order to achieve exascale systems, application resilience needs to be addressed. Some programming models, such as task-DAG (directed acyclic graphs) architectures, currently embed resilience features whereas traditional SPMD (single program, multiple data) and message-passing models do not. Since a large part of the community's code base follows the latter models, it is still required to take advantage of application characteristics to minimize the overheads of fault tolerance. To that end, this paper explores how recovering from hard process/node failures in a local manner is a natural approach for certain applications to obtain resilience at lower costs in faulty environments.more » In particular, this paper targets enabling online, semitransparent local recovery for stencil computations on current leadership-class systems as well as presents programming support and scalable runtime mechanisms. Also described and demonstrated in this paper is the effect of failure masking, which allows the effective reduction of impact on total time to solution due to multiple failures. Furthermore, we discuss, implement, and evaluate ghost region expansion and cell-to-rank remapping to increase the probability of failure masking. To conclude, this paper shows the integration of all aforementioned mechanisms with the S3D combustion simulation through an experimental demonstration (using the Titan system) of the ability to tolerate high failure rates (i.e., node failures every five seconds) with low overhead while sustaining performance at large scales. In addition, this demonstration also displays the failure masking probability increase resulting from the combination of both ghost region expansion and cell-to-rank remapping.« less

Scalable Failure Masking for Stencil Computations using Ghost Region Expansion and Cell to Rank Remapping

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamell, Marc; Teranishi, Keita; Kolla, Hemanth

In order to achieve exascale systems, application resilience needs to be addressed. Some programming models, such as task-DAG (directed acyclic graphs) architectures, currently embed resilience features whereas traditional SPMD (single program, multiple data) and message-passing models do not. Since a large part of the community's code base follows the latter models, it is still required to take advantage of application characteristics to minimize the overheads of fault tolerance. To that end, this paper explores how recovering from hard process/node failures in a local manner is a natural approach for certain applications to obtain resilience at lower costs in faulty environments.more » In particular, this paper targets enabling online, semitransparent local recovery for stencil computations on current leadership-class systems as well as presents programming support and scalable runtime mechanisms. Also described and demonstrated in this paper is the effect of failure masking, which allows the effective reduction of impact on total time to solution due to multiple failures. Furthermore, we discuss, implement, and evaluate ghost region expansion and cell-to-rank remapping to increase the probability of failure masking. To conclude, this paper shows the integration of all aforementioned mechanisms with the S3D combustion simulation through an experimental demonstration (using the Titan system) of the ability to tolerate high failure rates (i.e., node failures every five seconds) with low overhead while sustaining performance at large scales. In addition, this demonstration also displays the failure masking probability increase resulting from the combination of both ghost region expansion and cell-to-rank remapping.« less

A heuristic re-mapping algorithm reducing inter-level communication in SAMR applications.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steensland, Johan; Ray, Jaideep

2003-07-01

This paper aims at decreasing execution time for large-scale structured adaptive mesh refinement (SAMR) applications by proposing a new heuristic re-mapping algorithm and experimentally showing its effectiveness in reducing inter-level communication. Tests were done for five different SAMR applications. The overall goal is to engineer a dynamically adaptive meta-partitioner capable of selecting and configuring the most appropriate partitioning strategy at run-time based on current system and application state. Such a metapartitioner can significantly reduce execution times for general SAMR applications. Computer simulations of physical phenomena are becoming increasingly popular as they constitute an important complement to real-life testing. In manymore » cases, such simulations are based on solving partial differential equations by numerical methods. Adaptive methods are crucial to efficiently utilize computer resources such as memory and CPU. But even with adaption, the simulations are computationally demanding and yield huge data sets. Thus parallelization and the efficient partitioning of data become issues of utmost importance. Adaption causes the workload to change dynamically, calling for dynamic (re-) partitioning to maintain efficient resource utilization. The proposed heuristic algorithm reduced inter-level communication substantially. Since the complexity of the proposed algorithm is low, this decrease comes at a relatively low cost. As a consequence, we draw the conclusion that the proposed re-mapping algorithm would be useful to lower overall execution times for many large SAMR applications. Due to its usefulness and its parameterization, the proposed algorithm would constitute a natural and important component of the meta-partitioner.« less

Group Delay Tracking with the Sydney University Stellar Interferometer

NASA Astrophysics Data System (ADS)

Lawson, Peter R.

1994-08-01

The Sydney University Stellar Interferometer (SUSI) is a long baseline optical interferometer, located at the Paul Wild Observatory near Narrabri, in northern New South Wales, Australia. It is designed to measure stellar angular diameters using light collected from a pair of siderostats, with 11 fixed siderostats giving separations between 5 and 640 m. Apertures smaller than Fried's coherence length, r_0, are used and active tilt-compensation is employed. This ensures that when the beams are combined in the pupil plane the wavefronts are parallel. Fringes are detected when the optical path-difference between the arriving wavefronts is less than tne coherence length of light used for the observation. While observing a star it is necessary to compensate for the changes in pathlength due to the earth's rotation. It is also highly desirable to compensate for path changes due to the effects of atmospheric turbulence. Tracking the path-difference permits an accurate calibration of the fringe visibility, allows larger bandwidths to be used, and therefore improves the sensitivity of the instrument. I describe a fringe tracking system which I developed for SUSI, based on group delay tracking with a PAPA (Precision Analog Photon Address) detector. The method uses short exposure images of fringes, 1-10 ms, detected in the dispersed spectra of the combined starlight. The number of fringes across a fixed bandwidth of channeled spectrum is directly proportional to the path-difference between the arriving wavefronts. A Fast Fourier Transform, implemented in hardware, is used to calculate the spatial power spectrum of the fringes, thereby locating the delay. The visibility loss due to a non-constant fringe spacing on the detector is investigated, and the improvements obtained from rebinning the photon data are shown. The low light level limitations of group delay tracking are determined theoretically with emphasis on the probability of tracking error, rather than the signal-to-noise ratio. Experimental results from both laboratory studies and stellar observations are presented. These show the first closed-loop operation of a fringe tracking system based on observations of group delay with a stellar interferometer. The Sydney University PAPA camera, a photon counting array detector developed for use in this work, is also described. The design principles of the PAPA camera are outlined and the potential sources of image artifacts are identified. The artifacts arise from the use of optical encoding with Gray coded masks, and teh new camera is distinguished by its mask-plate, which was designed to overcome artifacts due to vignetting. Nw lens mounts are also presented which permit a simplified optical alignment without the need for tilt-plates. The performance of the camera is described. (SECTION: Dissertation Summaries)

Remapping Revisionist Historiography

ERIC Educational Resources Information Center

Gold, David

2012-01-01

Rhetoric and composition historiography has recently undergone a rapid transformation as scholars have complicated and challenged earlier narratives by examining diverse local histories and alternative rhetorical traditions. This revisionist scholarship has in turn created new research challenges, as scholars must now demonstrate connections…

ANALYSIS OF LOTIC MACROINVERTEBRATE ASSEMBLAGES IN CALIFORNIA'S CENTRAL VALLEY

EPA Science Inventory

Using multivariate and cluster analyses, we examined the relaitonships between chemical and physical characteristics and macroinvertebrate assemblages at sites sampled by R-EMAP in California's Central Valley. By contrasting results where community structure was summarized as met...

Wavefront sensing in space: flight demonstration II of the PICTURE sounding rocket payload

NASA Astrophysics Data System (ADS)

Douglas, Ewan S.; Mendillo, Christopher B.; Cook, Timothy A.; Cahoy, Kerri L.; Chakrabarti, Supriya

2018-01-01

A NASA sounding rocket for high-contrast imaging with a visible nulling coronagraph, the Planet Imaging Concept Testbed Using a Rocket Experiment (PICTURE) payload, has made two suborbital attempts to observe the warm dust disk inferred around Epsilon Eridani. The first flight in 2011 demonstrated a 5 mas fine pointing system in space. The reduced flight data from the second launch, on November 25, 2015, presented herein, demonstrate active sensing of wavefront phase in space. Despite several anomalies in flight, postfacto reduction phase stepping interferometer data provide insight into the wavefront sensing precision and the system stability for a portion of the pupil. These measurements show the actuation of a 32 × 32-actuator microelectromechanical system deformable mirror. The wavefront sensor reached a median precision of 1.4 nm per pixel, with 95% of samples between 0.8 and 12.0 nm per pixel. The median system stability, including telescope and coronagraph wavefront errors other than tip, tilt, and piston, was 3.6 nm per pixel, with 95% of samples between 1.2 and 23.7 nm per pixel.

CLUSTER ANALYSIS OF GREAT BASIN ECOREGIONS USING R-EMAP STREAM DATA

EPA Science Inventory

Ecological regions ( ecoregions ) are defined as areas of relative homogeneity in ecosystem type, quality and quantity of environmental resources. Ecoregions are identified by analyzing biotic and abiotic geographic patterns, which are natural and human related. Parameters used i...

Generalization of Prism Adaptation

ERIC Educational Resources Information Center

Redding, Gordon M.; Wallace, Benjamin

2006-01-01

Prism exposure produces 2 kinds of adaptive response. Recalibration is ordinary strategic remapping of spatially coded movement commands to rapidly reduce performance error. Realignment is the extraordinary process of transforming spatial maps to bring the origins of coordinate systems into correspondence. Realignment occurs when spatial…

ANALYSIS OF MACROINVERTEBRATE ASSEMBLAGES IN RELATION TO ENVIRONMENTAL GRADIENTS IN ROCKY MOUNTAIN STREAMS

EPA Science Inventory

Using redundancy analysis (RDA) and canonical correspondence analysis (CCA), we assessed relationships among chemical and physical characteristics and macroinvertebrate assemblages at stream sites sampled by the Regional Environmental Monitoring and Assessment Program (R-EMAP) in...

Binocular fusion and invariant category learning due to predictive remapping during scanning of a depthful scene with eye movements

PubMed Central

Grossberg, Stephen; Srinivasan, Karthik; Yazdanbakhsh, Arash

2015-01-01

How does the brain maintain stable fusion of 3D scenes when the eyes move? Every eye movement causes each retinal position to process a different set of scenic features, and thus the brain needs to binocularly fuse new combinations of features at each position after an eye movement. Despite these breaks in retinotopic fusion due to each movement, previously fused representations of a scene in depth often appear stable. The 3D ARTSCAN neural model proposes how the brain does this by unifying concepts about how multiple cortical areas in the What and Where cortical streams interact to coordinate processes of 3D boundary and surface perception, spatial attention, invariant object category learning, predictive remapping, eye movement control, and learned coordinate transformations. The model explains data from single neuron and psychophysical studies of covert visual attention shifts prior to eye movements. The model further clarifies how perceptual, attentional, and cognitive interactions among multiple brain regions (LGN, V1, V2, V3A, V4, MT, MST, PPC, LIP, ITp, ITa, SC) may accomplish predictive remapping as part of the process whereby view-invariant object categories are learned. These results build upon earlier neural models of 3D vision and figure-ground separation and the learning of invariant object categories as the eyes freely scan a scene. A key process concerns how an object's surface representation generates a form-fitting distribution of spatial attention, or attentional shroud, in parietal cortex that helps maintain the stability of multiple perceptual and cognitive processes. Predictive eye movement signals maintain the stability of the shroud, as well as of binocularly fused perceptual boundaries and surface representations. PMID:25642198

Figure-ground organization and the emergence of proto-objects in the visual cortex.

PubMed

von der Heydt, Rüdiger

2015-01-01

A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world and producing a structure that provides perceptual continuity and enables object-based attention. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields (CRF), but in addition their responses are modulated (enhanced or suppressed) depending on the location of a 'figure' relative to the edge in their receptive field. Each neuron has a fixed preference for location on one side or the other. This selectivity is derived from the image context far beyond the CRF. This paper reviews evidence indicating that border ownership selectivity reflects the formation of early object representations ('proto-objects'). The evidence includes experiments showing (1) reversal of border ownership signals with change of perceived object structure, (2) border ownership specific enhancement of responses in object-based selective attention, (3) persistence of border ownership signals in accordance with continuity of object perception, and (4) remapping of border ownership signals across saccades and object movements. Findings 1 and 2 can be explained by hypothetical grouping circuits that sum contour feature signals in search of objectness, and, via recurrent projections, enhance the corresponding low-level feature signals. Findings 3 and 4 might be explained by assuming that the activity of grouping circuits persists and can be remapped. Grouping, persistence, and remapping are fundamental operations of vision. Finding these operations manifest in low-level visual areas challenges traditional views of visual processing. New computational models need to be developed for a comprehensive understanding of the function of the visual cortex.

Figure–ground organization and the emergence of proto-objects in the visual cortex

PubMed Central

von der Heydt, Rüdiger

2015-01-01

A long history of studies of perception has shown that the visual system organizes the incoming information early on, interpreting the 2D image in terms of a 3D world and producing a structure that provides perceptual continuity and enables object-based attention. Recordings from monkey visual cortex show that many neurons, especially in area V2, are selective for border ownership. These neurons are edge selective and have ordinary classical receptive fields (CRF), but in addition their responses are modulated (enhanced or suppressed) depending on the location of a ‘figure’ relative to the edge in their receptive field. Each neuron has a fixed preference for location on one side or the other. This selectivity is derived from the image context far beyond the CRF. This paper reviews evidence indicating that border ownership selectivity reflects the formation of early object representations (‘proto-objects’). The evidence includes experiments showing (1) reversal of border ownership signals with change of perceived object structure, (2) border ownership specific enhancement of responses in object-based selective attention, (3) persistence of border ownership signals in accordance with continuity of object perception, and (4) remapping of border ownership signals across saccades and object movements. Findings 1 and 2 can be explained by hypothetical grouping circuits that sum contour feature signals in search of objectness, and, via recurrent projections, enhance the corresponding low-level feature signals. Findings 3 and 4 might be explained by assuming that the activity of grouping circuits persists and can be remapped. Grouping, persistence, and remapping are fundamental operations of vision. Finding these operations manifest in low-level visual areas challenges traditional views of visual processing. New computational models need to be developed for a comprehensive understanding of the function of the visual cortex. PMID:26579062

The programmable remapper: clinical applications for patients with field defects.

PubMed

Loshin, D S; Juday, R D

1989-06-01

NASA, Johnson Space Center is developing an electronic image remapper which will warp an image from one coordinate system onto another with great flexibility and speed. The Programmable Remapper will transform images at conventional video frame rate. The Remapper was designed to be used in conjunction with an optical correlator to enhance object recognition through "real time" Fourier analysis. We are investigating an additional potential application for the Remapper as a low-vision aid. In diseases which result in obvious field defects such as age-related maculopathy (ARM) or retinitis pigmentosa (RP), the Remapper can be used to redistribute onto the still-functioning retina the image information that would otherwise be lost due to the associated field defect. Compared with eccentric viewing, this process makes use of the acuity of a larger area of the retina. We envision the future aid to consist of a portable spectacle-mounted display with miniaturized camera input and the Remapper. The patient will view the remapped world on this display. Patients may require training with feedback as to eye and scotoma position in order to use the Remapper most effectively. The Remapper might be reduced in cost, weight, and size to the point of being a feasible low-vision prosthesis as a result of development required by military, space, and industrial utilization. In order to demonstrate how such an aid may work, we have generated static images on an image processor which have undergone radial-only remapping; i.e., image points are slid along radii, with their azimuths unchanged. The remapping process and the application to low vision along with static images are presented in this paper.

A high order cell-centered semi-Lagrangian scheme for multi-dimensional kinetic simulations of neutral gas flows

NASA Astrophysics Data System (ADS)

Güçlü, Y.; Hitchon, W. N. G.

2012-04-01

The term 'Convected Scheme' (CS) refers to a family of algorithms, most usually applied to the solution of Boltzmann's equation, which uses a method of characteristics in an integral form to project an initial cell forward to a group of final cells. As such the CS is a 'forward-trajectory' semi-Lagrangian scheme. For multi-dimensional simulations of neutral gas flows, the cell-centered version of this semi-Lagrangian (CCSL) scheme has advantages over other options due to its implementation simplicity, low memory requirements, and easier treatment of boundary conditions. The main drawback of the CCSL-CS to date has been its high numerical diffusion in physical space, because of the 2nd order remapping that takes place at the end of each time step. By means of a modified equation analysis, it is shown that a high order estimate of the remapping error can be obtained a priori, and a small correction to the final position of the cells can be applied upon remapping, in order to achieve full compensation of this error. The resulting scheme is 4th order accurate in space while retaining the desirable properties of the CS: it is conservative and positivity-preserving, and the overall algorithm complexity is not appreciably increased. Two monotone (i.e. non-oscillating) versions of the fourth order CCSL-CS are also presented: one uses a common flux-limiter approach; the other uses a non-polynomial reconstruction to evaluate the derivatives of the density function. The method is illustrated in simple one- and two-dimensional examples, and a fully 3D solution of the Boltzmann equation describing expansion of a gas into vacuum through a cylindrical tube.

Binocular fusion and invariant category learning due to predictive remapping during scanning of a depthful scene with eye movements.

PubMed

Grossberg, Stephen; Srinivasan, Karthik; Yazdanbakhsh, Arash

2014-01-01

How does the brain maintain stable fusion of 3D scenes when the eyes move? Every eye movement causes each retinal position to process a different set of scenic features, and thus the brain needs to binocularly fuse new combinations of features at each position after an eye movement. Despite these breaks in retinotopic fusion due to each movement, previously fused representations of a scene in depth often appear stable. The 3D ARTSCAN neural model proposes how the brain does this by unifying concepts about how multiple cortical areas in the What and Where cortical streams interact to coordinate processes of 3D boundary and surface perception, spatial attention, invariant object category learning, predictive remapping, eye movement control, and learned coordinate transformations. The model explains data from single neuron and psychophysical studies of covert visual attention shifts prior to eye movements. The model further clarifies how perceptual, attentional, and cognitive interactions among multiple brain regions (LGN, V1, V2, V3A, V4, MT, MST, PPC, LIP, ITp, ITa, SC) may accomplish predictive remapping as part of the process whereby view-invariant object categories are learned. These results build upon earlier neural models of 3D vision and figure-ground separation and the learning of invariant object categories as the eyes freely scan a scene. A key process concerns how an object's surface representation generates a form-fitting distribution of spatial attention, or attentional shroud, in parietal cortex that helps maintain the stability of multiple perceptual and cognitive processes. Predictive eye movement signals maintain the stability of the shroud, as well as of binocularly fused perceptual boundaries and surface representations.

Influence of spherical aberration, stimulus spatial frequency, and pupil apodisation on subjective refractions

PubMed Central

Bradley, Arthur; Xu, Renfeng; Thibos, Larry; Marin, Gildas; Hernandez, Martha

2014-01-01

Purpose To test competing hypotheses (Stiles Crawford pupil apodising or superior imaging of high spatial frequencies by the central pupil) for the pupil size independence of subjective refractions in the presence of primary spherical aberration. Methods Subjective refractions were obtained with a variety of test stimuli (high contrast letters, urban cityscape, high and low spatial frequency gratings) while modulating pupil diameter, levels of primary spherical aberration and pupil apodisation. Subjective refractions were also obtained with low-pass and high-pass stimuli and using “darker” and “sharper” subjective criteria. Results Subjective refractions for stimuli containing high spatial frequencies focus a near paraxial region of the pupil and are affected only slightly by level of Seidel spherical aberration, degree of pupil apodisation and pupil diameter, and generally focused a radius of about 1 to 1.5 mm from the pupil centre. Low spatial frequency refractions focus a marginal region of the pupil, and are significantly affected by level of spherical aberration, amount of pupil apodisation, and pupil size. Clinical refractions that employ the “darker” or “sharper” subjective criteria bias the patient to use lower or higher spatial frequencies respectively. Conclusions In the presence of significant levels of spherical aberration, the pupil size independence of subjective refractions occurs with or without Stiles Crawford apodisation for refractions that optimise high spatial frequency content in the image. If low spatial frequencies are optimised by a subjective refraction, spherical refractive error varies with spherical aberration, pupil size, and level of apodisation. As light levels drop from photopic to scotopic, therefore, we expect a shift from pupil size independent to pupil size dependent subjective refractions. Emphasising a “sharper” criterion during subjective refractions will improve image quality for high spatial frequencies and generate pupil size independent refractions. PMID:24397356

The Voice of the Pupils: An Experimental Comparison of Decisions Made by Elected Pupil Councils, Pupils in Referenda, and Teaching Staff

ERIC Educational Resources Information Center

Gilljam, Mikael; Esaiasson, Peter; Lindholm, Torun

2010-01-01

This article tests whether the form of decision-making used in school environments affects pupils' views on the legitimacy of the decisions made, and of the decision-making procedure. Building on political science theory on democratic decision-making, it compares pupils' reactions towards decisions made by pupil councils, by pupils via referendum,…

MULTIVARIATE ANALYSIS OF MACROINVERTEBRATE ASSEMBLAGES TO DETERMINE IMPACTS ON ROCKY MOUNTAIN STREAM ECOSYSTEMS

EPA Science Inventory

Using reduncancy (RDA) and canonical correlation analysis (CCA) we assessed relationships between chemical and physical characteristics and periphyton at 105 stream sites sampled by REMAP in the mineral belt of the southern Rockies ecoregion in Colorado. We contrasted results ob...

COMPARATIVE APPLICATION OF PERIPHYTON, MACROINVERTEBRATE AND FISH INDICES OF BIOTIC INTEGRITY TO SOUTHERN ROCKY MOUNTAIN STREAMS

EPA Science Inventory

We compared three assessments using macroinvertebrate, periphyton, and fish assemblages in streams sampled by the Regional Environmental Monitoring and Assessment Program (REMAP) in Colorado's Southern Rockies Ecoregion. We contrasted analyses using metrics for each group selecte...

Engagement of neural circuits underlying 2D spatial navigation in a rodent virtual reality system

PubMed Central

Aronov, Dmitriy; Tank, David W.

2015-01-01

SUMMARY Virtual reality (VR) enables precise control of an animal’s environment and otherwise impossible experimental manipulations. Neural activity in navigating rodents has been studied on virtual linear tracks. However, the spatial navigation system’s engagement in complete two-dimensional environments has not been shown. We describe a VR setup for rats, including control software and a large-scale electrophysiology system, which supports 2D navigation by allowing animals to rotate and walk in any direction. The entorhinal-hippocampal circuit, including place cells, grid cells, head direction cells and border cells, showed 2D activity patterns in VR similar to those in the real world. Hippocampal neurons exhibited various remapping responses to changes in the appearance or the shape of the virtual environment, including a novel form in which a VR-induced cue conflict caused remapping to lock to geometry rather than salient cues. These results suggest a general-purpose tool for novel types of experimental manipulations in navigating rats. PMID:25374363

A low diffusive Lagrange-remap scheme for the simulation of violent air-water free-surface flows

NASA Astrophysics Data System (ADS)

Bernard-Champmartin, Aude; De Vuyst, Florian

2014-10-01

In 2002, Després and Lagoutière [17] proposed a low-diffusive advection scheme for pure transport equation problems, which is particularly accurate for step-shaped solutions, and thus suited for interface tracking procedure by a color function. This has been extended by Kokh and Lagoutière [28] in the context of compressible multifluid flows using a five-equation model. In this paper, we explore a simplified variant approach for gas-liquid three-equation models. The Eulerian numerical scheme has two ingredients: a robust remapped Lagrange solver for the solution of the volume-averaged equations, and a low diffusive compressive scheme for the advection of the gas mass fraction. Numerical experiments show the performance of the computational approach on various flow reference problems: dam break, sloshing of a tank filled with water, water-water impact and finally a case of Rayleigh-Taylor instability. One of the advantages of the present interface capturing solver is its natural implementation on parallel processors or computers.

Automated cell-type classification in intact tissues by single-cell molecular profiling

PubMed Central

2018-01-01

A major challenge in biology is identifying distinct cell classes and mapping their interactions in vivo. Tissue-dissociative technologies enable deep single cell molecular profiling but do not provide spatial information. We developed a proximity ligation in situ hybridization technology (PLISH) with exceptional signal strength, specificity, and sensitivity in tissue. Multiplexed data sets can be acquired using barcoded probes and rapid label-image-erase cycles, with automated calculation of single cell profiles, enabling clustering and anatomical re-mapping of cells. We apply PLISH to expression profile ~2900 cells in intact mouse lung, which identifies and localizes known cell types, including rare ones. Unsupervised classification of the cells indicates differential expression of ‘housekeeping’ genes between cell types, and re-mapping of two sub-classes of Club cells highlights their segregated spatial domains in terminal airways. By enabling single cell profiling of various RNA species in situ, PLISH can impact many areas of basic and medical research. PMID:29319504

Eating behaviours of middle- and secondary-school pupils from the upper Silesian region in Poland.

PubMed

Szczepańska, Elżbieta; Szeja, Nicola; Szymkiewicz, Anna; Kowalska, Aleksandra; Lenard, Biruta; Bulwicka, Anna

2014-01-01

Eating behaviours of school-aged youth condition their emotional and psychophysical development. Moreover, they influence the effectiveness of learning and affect one's health and the quality of life at older age. The objective of the study was the evaluation of eating behaviours of the group of pupils from cities of the Upper Silesian region, as well as the identification of differences between middle-school and secondary-school pupils' eating behaviours. 902 pupils (474 middle-school and 428 secondary-school pupils) participated in the study. The research materials included questionnaires prepared by the author of the study, containing the questions about the pupils' eating habits. The middle-school pupils constituted 52.5% of the 902 pupils and the secondary-school pupils were 47.5% of the total. On average, 38.2% of the pupils consumed 4 meals daily. Wholemeal bread and/or groats were eaten daily by 34.4% of the pupils. Milk and/or milk drinks were consumed by 56.3% of the pupils every day and 33.5% of the respondents had also fermented milk drinks daily. 61.3% of the participants declared eating meat at least once a day and 44.9% of the pupils had fish once or twice a week. Vegetables and fruit were eaten daily by 61.4% and 66.6% of the pupils respectively. Sweets were consumed at least once a day by 50.6% of the pupils. Occasional consumption of fast-food products and ready-made meals was declared by 63.9% and 49.7% of the pupils respectively. Eating behaviours of the discussed group of pupils are mostly incorrect. There were differences found between the middle-school and secondary-school pupils' eating habits. The differences concerned the frequency of eating cheese and curd cheese, fruit, leguminous plant seeds, sweets, fast food products, sweetened drinks and ready-to made food products. eating behaviours, eating habits, eating frequency, pupils.

The Pupil Premium: Next Steps

ERIC Educational Resources Information Center

Sutton Trust, 2015

2015-01-01

The pupil premium was introduced by the Coalition government in April 2011 to provide additional funding for disadvantaged pupils. The main difference between the premium and previous funding for disadvantaged pupils is that the premium is linked to individual pupils. On July 1, 2015, The Pupil Premium Summit organized by the Education Endowment…

Improvement of reliability in multi-interferometer-based counterfactual deterministic communication with dissipation compensation.

PubMed

Liu, Chao; Liu, Jinhong; Zhang, Junxiang; Zhu, Shiyao

2018-02-05

The direct counterfactual quantum communication (DCQC) is a surprising phenomenon that quantum information can be transmitted without using any carriers of physical particles. The nested interferometers are promising devices for realizing DCQC as long as the number of interferometers goes to be infinity. Considering the inevitable loss or dissipation in practical experimental interferometers, we analyze the dependence of reliability on the number of interferometers, and show that the reliability of direct communication is being rapidly degraded with the large number of interferometers. Furthermore, we simulate and test this counterfactual deterministic communication protocol with a finite number of interferometers, and demonstrate the improvement of the reliability using dissipation compensation in interferometers.

Does the "Pupil Enterprise Programme" Influence Grades among Pupils with Special Needs?

ERIC Educational Resources Information Center

Johansen, Vegard; Somby, Hege M.

2016-01-01

This paper asks whether the Pupil Enterprise Programme (PEP) is a suitable working method for improving academic performance among pupils with special needs. Overall, 20% of pupils participate in PEP at some point during lower secondary school. Results from multilevel regression modelling indicate that pupils with special needs who have…

Pedagogy, Democracy, and Feminism: Rethinking the Public Sphere.

ERIC Educational Resources Information Center

Hernandez, Adriana

This book provides a shifting interplay of the terms pedagogy, democracy, and feminism around the idea of an emancipatory political project. Chapter 1, "Remapping Pedagogical Boundaries: Critical Pedagogy, Feminism, and a Discourse of Possibility," examines the pedagogical within a discourse of critique and possibility, and discusses the…

Pupil and Staff Perceptions of Rewards at a Pupil Referral Unit

ERIC Educational Resources Information Center

Capstick, Joanna

2005-01-01

The present study investigated the perceptions of both pupils and staff at a pupil referral unit (PRU) towards the reward system currently in use. The main aims were to establish whether teachers and pupils perceived the same rewards as effective, to determine whether staff and pupils perceived that rewards changed behaviour, and finally whether…

Robust pupil center detection using a curvature algorithm

NASA Technical Reports Server (NTRS)

Zhu, D.; Moore, S. T.; Raphan, T.; Wall, C. C. (Principal Investigator)

1999-01-01

Determining the pupil center is fundamental for calculating eye orientation in video-based systems. Existing techniques are error prone and not robust because eyelids, eyelashes, corneal reflections or shadows in many instances occlude the pupil. We have developed a new algorithm which utilizes curvature characteristics of the pupil boundary to eliminate these artifacts. Pupil center is computed based solely on points related to the pupil boundary. For each boundary point, a curvature value is computed. Occlusion of the boundary induces characteristic peaks in the curvature function. Curvature values for normal pupil sizes were determined and a threshold was found which together with heuristics discriminated normal from abnormal curvature. Remaining boundary points were fit with an ellipse using a least squares error criterion. The center of the ellipse is an estimate of the pupil center. This technique is robust and accurately estimates pupil center with less than 40% of the pupil boundary points visible.

Quantum Interferometry

NASA Technical Reports Server (NTRS)

Dowling, Jonathan P.

2000-01-01

Recently, several researchers, including yours truly, have been able to demonstrate theoretically that quantum photon entanglement has the potential to also revolutionize the entire field of optical interferometry, by providing many orders of magnitude improvement in interferometer sensitivity. The quantum entangled photon interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like 1/Sqrt[N], where N is the number of particles (photons, electrons, atoms, neutrons) passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of Sqrt[N] (square root of N) to scale like 1/N, which is the limit imposed by the Heisenberg Uncertainty Principle. For optical (laser) interferometers operating at milliwatts of optical power, this quantum sensitivity boost corresponds to an eight-order-of-magnitude improvement of signal to noise. Applications are to tests of General Relativity such as ground and orbiting optical interferometers for gravity wave detection, Laser Interferometer Gravity Observatory (LIGO) and the European Laser Interferometer Space Antenna (LISA), respectively.

Pupil-mimicry conditions trust in partners: moderation by oxytocin and group membership

PubMed Central

De Dreu, Carsten K. W.

2017-01-01

Across species, oxytocin, an evolutionarily ancient neuropeptide, facilitates social communication by attuning individuals to conspecifics' social signals, fostering trust and bonding. The eyes have an important signalling function; and humans use their salient and communicative eyes to intentionally and unintentionally send social signals to others, by contracting the muscles around their eyes and pupils. In our earlier research, we observed that interaction partners with dilating pupils are trusted more than partners with constricting pupils. But over and beyond this effect, we found that the pupil sizes of partners synchronize and that when pupils synchronously dilate, trust is further boosted. Critically, this linkage between mimicry and trust was bound to interactions between ingroup members. The current study investigates whether these findings are modulated by oxytocin and sex of participant and partner. Using incentivized trust games with partners from ingroup and outgroup whose pupils dilated, remained static or constricted, this study replicates our earlier findings. It further reveals that (i) male participants withhold trust from partners with constricting pupils and extend trust to partners with dilating pupils, especially when given oxytocin rather than placebo; (ii) female participants trust partners with dilating pupils most, but this effect is blunted under oxytocin; (iii) under oxytocin rather than placebo, pupil dilation mimicry is weaker and pupil constriction mimicry stronger; and (iv) the link between pupil constriction mimicry and distrust observed under placebo disappears under oxytocin. We suggest that pupil-contingent trust is parochial and evolved in social species in and because of group life. PMID:28250181

In-Line Fiber Optic Interferometric Sensors in Single-Mode Fibers

PubMed Central

Zhu, Tao; Wu, Di; Liu, Min; Duan, De-Wen

2012-01-01

In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It's known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented. PMID:23112608

Adaptive optics retinal imaging with automatic detection of the pupil and its boundary in real time using Shack-Hartmann images.

PubMed

de Castro, Alberto; Sawides, Lucie; Qi, Xiaofeng; Burns, Stephen A

2017-08-20

Retinal imaging with an adaptive optics (AO) system usually requires that the eye be centered and stable relative to the exit pupil of the system. Aberrations are then typically corrected inside a fixed circular pupil. This approach can be restrictive when imaging some subjects, since the pupil may not be round and maintaining a stable head position can be difficult. In this paper, we present an automatic algorithm that relaxes these constraints. An image quality metric is computed for each spot of the Shack-Hartmann image to detect the pupil and its boundary, and the control algorithm is applied only to regions within the subject's pupil. Images on a model eye as well as for five subjects were obtained to show that a system exit pupil larger than the subject's eye pupil could be used for AO retinal imaging without a reduction in image quality. This algorithm automates the task of selecting pupil size. It also may relax constraints on centering the subject's pupil and on the shape of the pupil.

WV R-EMAP SMALL WATERSHED CHARACTERIZATION, CLASSIFICATION, AND ASSESSMENT FOR WEST VIRGINIA UTILIZING EMAP DESIGN AND TOOLS

EPA Science Inventory

A probabilistic watershed-based framework was developed to encompass wadeable streams within all three ecoregions of West Virginia, with the exclusion noted below. In Phase I of the project (year 2001), we developed and applied a probabilistic watershed-based sampling framework ...

Remapping Place and Narrative in Native American Literature: David Treuer's "The Hiawatha"

ERIC Educational Resources Information Center

Kirwan, Padraig

2007-01-01

David Treuer's 1997 novel, "The Hiawatha," engages the traditional literary strategies employed by Native American writing, compares those strategies to earlier narratives (Native American and canonically American), offers a reassessment of indigenous novelistic structures, engages critical responses to tribal fiction, and does so in response to…

Remapping Nominal Features in the Second Language

ERIC Educational Resources Information Center

Cho, Ji-Hyeon Jacee

2012-01-01

This dissertation investigates second language (L2) development in the domains of morphosyntax and semantics. Specifically, it examines the acquisition of definiteness and specificity in Russian within the Feature Re-assembly framework (Lardiere, 2009), according to which the hardest L2 learning task is not to reset parameters but to reconfigure,…

A Design Rationale Capture Using REMAP/MM

DTIC Science & Technology

1994-06-01

company-wide down-sizing, the power company has determined that an automated service order processing system is the most economical solution. This new...service order processing system for a large power company can easily be 37 led. A system of this complexity would typically require three to five years

Power and Identity in the Creative Writing Classroom

ERIC Educational Resources Information Center

Leahy, Anna, Ed.

2005-01-01

This book remaps theories and practices for teaching creative writing at university and college level. This collection critiques well-established approaches for teaching creative writing in all genres and builds a comprehensive and adaptable pedagogy based on issues of authority, power, and identity. A long-needed reflection, this book shapes…

Development of Benthic Indicators for Nearshore Coastal Waters of New Jersey - A REMAP Project

EPA Science Inventory

EPA's National Coastal Assessment (NCA) is providing the first complete, consistent dataset on the condition of benthic communities in the nation's estuaries. Prior to NCA, New Jersey based its evaluation of the ecological condition of its coastal waters solely on dissolved oxyg...

Cryogenic Pupil Alignment Test Architecture for Aberrated Pupil Images

NASA Technical Reports Server (NTRS)

Bos, Brent; Kubalak, David A.; Antonille, Scott; Ohl, Raymond; Hagopian, John G.

2009-01-01

A document describes cryogenic test architecture for the James Webb Space Telescope (JWST) integrated science instrument module (ISIM). The ISIM element primarily consists of a mechanical metering structure, three science instruments, and a fine guidance sensor. One of the critical optomechanical alignments is the co-registration of the optical telescope element (OTE) exit pupil with the entrance pupils of the ISIM instruments. The test architecture has been developed to verify that the ISIM element will be properly aligned with the nominal OTE exit pupil when the two elements come together. The architecture measures three of the most critical pupil degrees-of-freedom during optical testing of the ISIM element. The pupil measurement scheme makes use of specularly reflective pupil alignment references located inside the JWST instruments, ground support equipment that contains a pupil imaging module, an OTE simulator, and pupil viewing channels in two of the JWST flight instruments. Pupil alignment references (PARs) are introduced into the instrument, and their reflections are checked using the instrument's mirrors. After the pupil imaging module (PIM) captures a reflected PAR image, the image will be analyzed to determine the relative alignment offset. The instrument pupil alignment preferences are specularly reflective mirrors with non-reflective fiducials, which makes the test architecture feasible. The instrument channels have fairly large fields of view, allowing PAR tip/tilt tolerances on the order of 0.5deg.

Variations of pupil centration and their effects on video eye tracking.

PubMed

Wildenmann, Ulrich; Schaeffel, Frank

2013-11-01

To evaluate measurement errors that are introduced in video eye tracking when pupil centration changes with pupil size. Software was developed under Visual C++ to track both pupil centre and corneal centre at 87 Hz sampling rate at baseline pupil sizes of 4.75 mm (800 lux room illuminance) and while pupil constrictions were elicited by a flashlight. Corneal centres were determined by a circle fit through the pixels detected at the corneal margin by an edge detection algorithm. Standard deviations for repeated measurements were ± 0.04 mm for horizontal pupil centre position and ± 0.04 mm for horizontal corneal centre positions and ±0.03 mm for vertical pupil centre position and ± 0.05 mm for vertical corneal centre position. Ten subjects were tested (five female, five male, age 25-58 years). At 4 mm pupil sizes, the pupils were nasally decentred relative to the corneal centre by 0.18 ± 0.19 mm in the right eyes and -0.14 ± 0.22 mm in the left eyes. Vertical decentrations were 0.30 ± 0.30 mm and 0.27 ± 0.29 mm, respectively, always in a superior direction. At baseline pupil sizes (the natural pupil sizes at 800 lux) of 4.75 ± 0.52 mm, the decentrations became less (right and left eyes: horizontal 0.17 ± 0.20 mm and -0.12 ± 0.22 mm, and vertical 0.26 ± 0.28 mm and 0.20 ± 0.25 mm). While pupil decentration changed minimally in eight of the subjects, it shifted considerably in two others. Averaged over all subjects, the shift of the pupil centre position per millimetre pupil constriction was not significant (right and left eyes: -0.03 ± 0.07 mm and 0.03 ± 0.04 mm nasally per mm pupil size change, respectively, and -0.04 ± 0.06 mm and -0.05 ± 0.12 mm superiorly). Direction and magnitude of the changes in pupil centration could not be predicted from the initial decentration at baseline pupil sizes. In line with data in the literature, the pupil centre was significantly decentred relative to the corneal centre in the nasal and superior direction. Pupil decentration changed significantly with pupil size by 0.05 mm on average for 1 mm of constriction. Assuming a Hirschberg ratio of 12° mm(-1) , a shift of 0.05 mm is equivalent to a measurement error in a Purkinje image-based eye tracker of 0.6°. However, the induced measurement error could also exceed 1.5° in some subjects for only a 1 mm change in pupil size. © 2013 The Authors Ophthalmic & Physiological Optics © 2013 The College of Optometrists.

New methods of multimode fiber interferometer signal processing

NASA Astrophysics Data System (ADS)

Vitrik, Oleg B.; Kulchin, Yuri N.; Maxaev, Oleg G.; Kirichenko, Oleg V.; Kamenev, Oleg T.; Petrov, Yuri S.

1995-06-01

New methods of multimode fiber interferometers signal processing are suggested. For scheme of single fiber multimode interferometers with two excited modes, the method based on using of special fiber unit is developed. This unit provides the modes interaction and further sum optical field filtering. As a result the amplitude of output signal is modulated by external influence on interferometer. The stabilization of interferometer sensitivity is achieved by using additional special modulation of output signal. For scheme of single fiber multimode interferometers with excitation of wide mode spectrum, the signal of intermode interference is registered by photodiode matrix and then special electronic unit performs correlation processing. For elimination of temperature destabilization, the registered signal is adopted to multimode interferometers optical signal temperature changes. The achieved parameters for double mode scheme: temporary stability--0.6% per hour, sensitivity to interferometer length deviations--3,2 nm; for multimode scheme: temperature stability--(0.5%)/(K), temporary nonstability--0.2% per hour, sensitivity to interferometer length deviations--20 nm, dynamic range--35 dB.

Examining the Effect of Class Size on Classroom Engagement and Teacher-Pupil Interaction: Differences in Relation to Pupil Prior Attainment and Primary vs. Secondary Schools

ERIC Educational Resources Information Center

Blatchford, Peter; Bassett, Paul; Brown, Penelope

2011-01-01

It is widely recognized that we need to know more about effects of class size on classroom interactions and pupil behavior. This paper extends research by comparing effects on pupil classroom engagement and teacher-pupil interaction, and examining if effects vary by pupil attainment level and between primary and secondary schools. Systematic…

Investigation of Space Interferometer Control Using Imaging Sensor Output Feedback

NASA Technical Reports Server (NTRS)

Leitner, Jesse A.; Cheng, Victor H. L.

2003-01-01

Numerous space interferometry missions are planned for the next decade to verify different enabling technologies towards very-long-baseline interferometry to achieve high-resolution imaging and high-precision measurements. These objectives will require coordinated formations of spacecraft separately carrying optical elements comprising the interferometer. High-precision sensing and control of the spacecraft and the interferometer-component payloads are necessary to deliver sub-wavelength accuracy to achieve the scientific objectives. For these missions, the primary scientific product of interferometer measurements may be the only source of data available at the precision required to maintain the spacecraft and interferometer-component formation. A concept is studied for detecting the interferometer's optical configuration errors based on information extracted from the interferometer sensor output. It enables precision control of the optical components, and, in cases of space interferometers requiring formation flight of spacecraft that comprise the elements of a distributed instrument, it enables the control of the formation-flying vehicles because independent navigation or ranging sensors cannot deliver the high-precision metrology over the entire required geometry. Since the concept can act on the quality of the interferometer output directly, it can detect errors outside the capability of traditional metrology instruments, and provide the means needed to augment the traditional instrumentation to enable enhanced performance. Specific analyses performed in this study include the application of signal-processing and image-processing techniques to solve the problems of interferometer aperture baseline control, interferometer pointing, and orientation of multiple interferometer aperture pairs.

Pupil-mimicry conditions trust in partners: moderation by oxytocin and group membership.

PubMed

Kret, Mariska E; De Dreu, Carsten K W

2017-03-15

Across species, oxytocin, an evolutionarily ancient neuropeptide, facilitates social communication by attuning individuals to conspecifics' social signals, fostering trust and bonding. The eyes have an important signalling function; and humans use their salient and communicative eyes to intentionally and unintentionally send social signals to others, by contracting the muscles around their eyes and pupils. In our earlier research, we observed that interaction partners with dilating pupils are trusted more than partners with constricting pupils. But over and beyond this effect, we found that the pupil sizes of partners synchronize and that when pupils synchronously dilate, trust is further boosted. Critically, this linkage between mimicry and trust was bound to interactions between ingroup members. The current study investigates whether these findings are modulated by oxytocin and sex of participant and partner. Using incentivized trust games with partners from ingroup and outgroup whose pupils dilated, remained static or constricted, this study replicates our earlier findings. It further reveals that (i) male participants withhold trust from partners with constricting pupils and extend trust to partners with dilating pupils, especially when given oxytocin rather than placebo; (ii) female participants trust partners with dilating pupils most, but this effect is blunted under oxytocin; (iii) under oxytocin rather than placebo, pupil dilation mimicry is weaker and pupil constriction mimicry stronger; and (iv) the link between pupil constriction mimicry and distrust observed under placebo disappears under oxytocin. We suggest that pupil-contingent trust is parochial and evolved in social species in and because of group life. © 2017 The Authors.

Nonlocal polarization interferometer for entanglement detection

DOE PAGES

Williams, Brian P.; Humble, Travis S.; Grice, Warren P.

2014-10-30

We report a nonlocal interferometer capable of detecting entanglement and identifying Bell states statistically. This is possible due to the interferometer's unique correlation dependence on the antidiagonal elements of the density matrix, which have distinct bounds for separable states and unique values for the four Bell states. The interferometer consists of two spatially separated balanced Mach-Zehnder or Sagnac interferometers that share a polarization-entangled source. Correlations between these interferometers exhibit nonlocal interference, while single-photon interference is suppressed. This interferometer also allows for a unique version of the Clauser-Horne-Shimony-Holt Bell test where the local reality is the photon polarization. In conclusion, wemore » present the relevant theory and experimental results.« less

A Comparison of Structurally Connected and Multiple Spacecraft Interferometers

NASA Technical Reports Server (NTRS)

Surka, Derek M.; Crawley, Edward F.

1996-01-01

Structurally connected and multiple spacecraft interferometers are compared in an attempt to establish the maximum baseline (referred to as the "cross-over baseline") for which it is preferable to operate a single-structure interferometer in space rather than an interferometer composed of numerous, smaller spacecraft. This comparison is made using the total launched mass of each configuration as the comparison metric. A framework of study within which structurally connected and multiple spacecraft interferometers can be compared is presented in block diagram form. This methodology is then applied to twenty-two different combinations of trade space parameters to investigate the effects of different orbits, orientations, truss materials, propellants, attitude control actuators, onboard disturbance sources, and performance requirements on the cross-over baseline. Rotating interferometers and the potential advantages of adding active structural control to the connected truss of the structurally connected interferometer are also examined. The minimum mass design of the structurally connected interferometer that meets all performance-requirements and satisfies all imposed constraints is determined as a function of baseline. This minimum mass design is then compared to the design of the multiple spacecraft interferometer. It is discovered that the design of the minimum mass structurally connected interferometer that meets all performance requirements and constraints in solar orbit is limited by the minimum allowable aspect ratio, areal density, and gage of the struts. In the formulation of the problem used in this study, there is no advantage to adding active structural control to the truss for interferometers in solar orbit. The cross-over baseline for missions of practical duration (ranging from one week to thirty years) in solar orbit is approximately 400 m for non-rotating interferometers and 650 m for rotating interferometers.

Urban Density and Pupil Attainment. CEE DP 80

ERIC Educational Resources Information Center

Gibbons, Stephen; Silva, Olmo

2007-01-01

We explore the association between urban density and pupil attainment using three cohorts of pupils in schooling in England. Although--as widely recognised--attainment in dense urban places is low on average, this is not because urban environments disadvantage pupils, but because the most disadvantaged pupils with low average attainments attend…

Pupils' Understanding of Air Pollution

ERIC Educational Resources Information Center

Dimitriou, Anastasia; Christidou, Vasilia

2007-01-01

This paper reports on a study of pupils' knowledge and understanding of atmospheric pollution. Specifically, the study is aimed at identifying: 1) the extent to which pupils conceptualise the term "air pollution" in a scientifically appropriate way; 2) pupils' knowledge of air pollution sources and air pollutants; and 3) pupils'…

Comparison of exact pupil astigmatism conditions with Seidel approximations

NASA Astrophysics Data System (ADS)

Zhao, Chunyu; Burge, James H.

2002-12-01

The aberrations of axisymmetric imaging systems can be calculated to third order by use of the Seidel formulas. The Coddington equations give aberrations that have quadratic dependence on the pupil, for all field points. The pupil astigmatism conditions were recently developed to predict and control aberrations that have quadratic field dependence and arbitrary pupil dependence. We investigate the relationship between the exact pupil astigmatism conditions and the classical Seidel treatment of pupil aberrations.

Safe and sensible preprocessing and baseline correction of pupil-size data.

PubMed

Mathôt, Sebastiaan; Fabius, Jasper; Van Heusden, Elle; Van der Stigchel, Stefan

2018-02-01

Measurement of pupil size (pupillometry) has recently gained renewed interest from psychologists, but there is little agreement on how pupil-size data is best analyzed. Here we focus on one aspect of pupillometric analyses: baseline correction, i.e., analyzing changes in pupil size relative to a baseline period. Baseline correction is useful in experiments that investigate the effect of some experimental manipulation on pupil size. In such experiments, baseline correction improves statistical power by taking into account random fluctuations in pupil size over time. However, we show that baseline correction can also distort data if unrealistically small pupil sizes are recorded during the baseline period, which can easily occur due to eye blinks, data loss, or other distortions. Divisive baseline correction (corrected pupil size = pupil size/baseline) is affected more strongly by such distortions than subtractive baseline correction (corrected pupil size = pupil size - baseline). We discuss the role of baseline correction as a part of preprocessing of pupillometric data, and make five recommendations: (1) before baseline correction, perform data preprocessing to mark missing and invalid data, but assume that some distortions will remain in the data; (2) use subtractive baseline correction; (3) visually compare your corrected and uncorrected data; (4) be wary of pupil-size effects that emerge faster than the latency of the pupillary response allows (within ±220 ms after the manipulation that induces the effect); and (5) remove trials on which baseline pupil size is unrealistically small (indicative of blinks and other distortions).

A Novel Method of High Accuracy, Wavefront Phase and Amplitude Correction for Coronagraphy

NASA Technical Reports Server (NTRS)

Bowers, Charles W.; Woodgate, Bruce E.; Lyon, Richard G.

2003-01-01

Detection of extra-solar, and especially terrestrial-like planets, using coronagraphy requires an extremely high level of wavefront correction. For example, the study of Woodruff et al. (2002) has shown that phase uniformity of order 10(exp -4)lambda(rms) must be achieved over the critical range of spatial frequencies to produce the approx. 10(exp 10) contrast needed for the Terrestrial Planet Finder (TPF) mission. Correction of wavefront phase errors to this level may be accomplished by using a very high precision deformable mirror (DM). However, not only phase but also amplitude uniformity of the same scale (approx. 10(exp -4)) and over the same spatial frequency range must be simultaneously obtained to remove all residual speckle in the image plane. We present a design for producing simultaneous wavefront phase and amplitude uniformity to high levels from an input wavefront of lower quality. The design uses a dual Michelson interferometer arrangement incorporating two DM and a single, fixed mirror (all at pupils) and two beamsplitters: one with unequal (asymmetric) beam splitting and one with symmetric beam splitting. This design allows high precision correction of both phase and amplitude using DM with relatively coarse steps and permits a simple correction algorithm.

Comparative Sensitivities of Gravitational Wave Detectors Based on Atom Interferometers and Light Interferometers

NASA Technical Reports Server (NTRS)

Baker, John G.; Thorpe, J. I.

2012-01-01

We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.

A compact semiconductor digital interferometer and its applications

NASA Astrophysics Data System (ADS)

Britsky, Oleksander I.; Gorbov, Ivan V.; Petrov, Viacheslav V.; Balagura, Iryna V.

2015-05-01

The possibility of using semiconductor laser interferometers to measure displacements at the nanometer scale was demonstrated. The creation principles of miniature digital Michelson interferometers based on semiconductor lasers were proposed. The advanced processing algorithm for the interferometer quadrature signals was designed. It enabled to reduce restrictions on speed of measured movements. A miniature semiconductor digital Michelson interferometer was developed. Designing of the precision temperature stability system for miniature low-cost semiconductor laser with 0.01ºС accuracy enabled to use it for creation of compact interferometer rather than a helium-neon one. Proper firmware and software was designed for the interferometer signals real-time processing and conversion in to respective shifts. In the result the relative displacement between 0-500 mm was measured with a resolution of better than 1 nm. Advantages and disadvantages of practical use of the compact semiconductor digital interferometer in seismometers for the measurement of shifts were shown.

A Martin-Puplett cartridge FIR interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Roger J.; Penniman, Edwin E.; Jarboe, Thomas R.

2004-10-01

A compact prealigned Martin-Puplett interferometer (MPI) cartridge for plasma interferometry is described. The MPI cartridge groups all components of a MP interferometer, with the exception of the end mirror for the scene beam, on a stand-alone rigid platform. The interferometer system is completed by positioning a cartridge anywhere along and coaxial with the scene beam, considerably reducing the amount of effort in alignment over a discrete component layout. This allows the interferometer to be expanded to any number of interferometry chords consistent with optical access, limited only by the laser power. The cartridge interferometer has been successfully incorporated as amore » second chord on the Helicity Injected Torus II (HIT-II) far infrared interferometer system and a comparison with the discrete component system is presented. Given the utility and compactness of the cartridge, a possible design for a five-chord interferometer arrangement on the HIT-II device is described.« less

The impact of luminance on tonic and phasic pupillary responses to sustained cognitive load.

PubMed

Peysakhovich, Vsevolod; Vachon, François; Dehais, Frédéric

2017-02-01

Pupillary reactions independent of light conditions have been linked to cognition for a long time. However, the light conditions can impact the cognitive pupillary reaction. Previous studies underlined the impact of luminance on pupillary reaction, but it is still unclear how luminance modulates the sustained and transient components of pupillary reaction - tonic pupil diameter and phasic pupil response. In the present study, we investigated the impact of the luminance on these two components under sustained cognitive load. Fourteen participants performed a novel working memory task combining mathematical computations with a classic n-back task. We studied both tonic pupil diameter and phasic pupil response under low (1-back) and high (2-back) working memory load and two luminance levels (gray and white). We found that the impact of working memory load on the tonic pupil diameter was modulated by the level of luminance, the increase in tonic pupil diameter with the load being larger under lower luminance. In contrast, the smaller phasic pupil response found under high load remained unaffected by luminance. These results showed that luminance impacts the cognitive pupillary reaction - tonic pupil diameter (phasic pupil response) being modulated under sustained (respectively, transient) cognitive load. These findings also support the relationship between the locus-coeruleus system, presumably functioning in two firing modes - tonic and phasic - and the pupil diameter. We suggest that the tonic pupil diameter tracks the tonic activity of the locus-coeruleus while phasic pupil response reflects its phasic activity. Besides, the designed novel cognitive paradigm allows the simultaneous manipulation of sustained and transient components of the cognitive load and is useful for dissociating the effects on the tonic pupil diameter and phasic pupil response. Copyright © 2016 Elsevier B.V. All rights reserved.

Pupillometry in brain death: differences in pupillary diameter between paediatric and adult subjects.

PubMed

Olgun, Gokhan; Newey, Christopher R; Ardelt, Agnieszka

2015-11-01

The determination of brain death in neonates, infants, children and adults relies on a clinical diagnosis based on the absence of neurological function with a known irreversible cause of brain injury. Evaluation of pupil size and non-reactivity is a requisite for determination of brain death. There are no studies in the literature that quantitatively assess pupil size in brain dead children and adults. Infants, children and adults diagnosed with brain death were included in the study. Pupils were measured with a quantitative pupillometer (Forsite; Neuroptics, Irvine, CA, USA). Median, minimum and maximum pupil sizes were documented and the results were adjudicated for age, vasopressor use and temperature. Median right and left pupil sizes were 5.01 ± 0.85 mm and 5.12 ± 0.87 mm, respectively, with a range between 3.69 and 7.34 mm. Paediatric pupils were larger than adult pupils (right pupil 5.53 vs 4.73 mm p: 0.018; left pupil 5.87 vs 4.77 mm P: 0.03), and there was no correlation of pupil size with temperature or increasing number of vasopressors. This is the first study in the literature objectively evaluating pupil sizes in infants, children and adults diagnosed with brain death. We observed variation between observed pupil size and that expected based on brain death determination guidelines.

Pupil-class determinants of aggressive and victim behaviour in pupils.

PubMed

Mooij, T

1998-09-01

Aggressive behaviour in pupils is expressed in, e.g., bullying, sexual harassment, and violence. Different kinds of variables could be relevant in explaining a pupil's aggressive or victim behaviour. To develop a multilevel theoretical and empirical explanation for different kinds of aggressive and victim behaviour displayed by pupils in a classroom and school environment. A national survey was carried out to identify different kinds of aggressive and victim behaviour displayed by pupils and to assess other variables related to pupils, classes, and schools. A total of 1998 pupils from 100 third and fourth year classes attending 71 different secondary schools took part in the research. Data were analysed by a series of secondary multilevel analyses using the MLA-program. Being a boy, being more extravert, being more disagreeable, coming across fewer teachers with positive teaching behaviour, and attending a lower type of secondary school, help explain why someone is a perpetrator as such. Being a boy, being more disagreeable, being more emotionally unstable, being open to new ideas, and seeing more teachers as being strict, function as explanatory pupil variables for victim behaviour. Other pupil level variables determine more specific aggressive and victim behaviour aspects. Various other class level and school level variables are relevant, too. Personal and environmental pupil variables are more important than class variables but class variables are in turn more important than school variables in explaining a pupil's aggressive and victim behaviour.

Recent observations with phase-contrast x-ray computed tomography

NASA Astrophysics Data System (ADS)

Momose, Atsushi; Takeda, Tohoru; Itai, Yuji; Tu, Jinhong; Hirano, Keiichi

1999-09-01

Recent development in phase-contrast X-ray computed tomography using an X-ray interferometer is reported. To observe larger samples than is possible with our previous X-ray interferometer, a large monolithic X-ray interferometer and a separated-type X-ray interferometer were studied. At the present time, 2.5 cm X 1.5 cm interference patterns have been generated with the X-ray interferometers using synchrotron X-rays. The large monolithic X-ray interferometer has produced interference fringes with 80% visibility, and has been used to measure various tissues. To produce images with higher spatial resolution, we fabricated another X-ray interferometer whose wafer was partially thinned by chemical etching. A preliminary test suggested that the spatial resolution has been improved.

A heterodyne interferometer with periodic nonlinearities smaller than ±10 pm

NASA Astrophysics Data System (ADS)

Weichert, C.; Köchert, P.; Köning, R.; Flügge, J.; Andreas, B.; Kuetgens, U.; Yacoot, A.

2012-09-01

The PTB developed a new optical heterodyne interferometer in the context of the European joint research project ‘Nanotrace’. A new optical concept using plane-parallel plates and spatially separated input beams to minimize the periodic nonlinearities was realized. Furthermore, the interferometer has the resolution of a double-path interferometer, compensates for possible angle variations between the mirrors and the interferometer optics and offers a minimal path difference between the reference and the measurement arm. Additionally, a new heterodyne phase evaluation based on an analogue to digital converter board with embedded field programmable gate arrays was developed, providing a high-resolving capability in the single-digit picometre range. The nonlinearities were characterized by a comparison with an x-ray interferometer, over a measurement range of 2.2 periods of the optical interferometer. Assuming an error-free x-ray interferometer, the nonlinearities are considered to be the deviation of the measured displacement from a best-fit line. For the proposed interferometer, nonlinearities smaller than ±10 pm were observed without any quadrature fringe correction.

The use of x-ray interferometry to investigate the linearity of the NPL Differential Plane Mirror Optical Interferometer

NASA Astrophysics Data System (ADS)

Yacoot, Andrew; Downs, Michael J.

2000-08-01

The x-ray interferometer from the combined optical and x-ray interferometer (COXI) facility at NPL has been used to investigate the performance of the NPL Jamin Differential Plane Mirror Interferometer when it is fitted with stabilized and unstabilized lasers. This Jamin interferometer employs a common path design using a double pass configuration and one fringe is realized by a displacement of 158 nm between its two plane mirror retroreflectors. Displacements over ranges of several optical fringes were measured simultaneously using the COXI x-ray interferometer and the Jamin interferometer and the results were compared. In order to realize the highest measurement accuracy from the Jamin interferometer, the air paths were shielded to prevent effects from air turbulence and electrical signals generated by the photodetectors were analysed and corrected using an optimizing routine in order to subdivide the optical fringes accurately. When an unstabilized laser was used the maximum peak-to-peak difference between the two interferometers was 80 pm, compared with 20 pm when the stabilized laser was used.

Phase and Pupil Amplitude Recovery for JWST Space-Optics Control

NASA Technical Reports Server (NTRS)

Dean, B. H.; Zielinski, T. P.; Smith, J. S.; Bolcar, M. R.; Aronstein, D. L.; Fienup, J. R.

2010-01-01

This slide presentation reviews the phase and pupil amplitude recovery for the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam). It includes views of the Integrated Science Instrument Module (ISIM), the NIRCam, examples of Phase Retrieval Data, Ghost Irradiance, Pupil Amplitude Estimation, Amplitude Retrieval, Initial Plate Scale Estimation using the Modulation Transfer Function (MTF), Pupil Amplitude Estimation vs lambda, Pupil Amplitude Estimation vs. number of Images, Pupil Amplitude Estimation vs Rotation (clocking), and Typical Phase Retrieval Results Also included is information about the phase retrieval approach, Non-Linear Optimization (NLO) Optimized Diversity Functions, and Least Square Error vs. Starting Pupil Amplitude.

[The role of physical education teachers to support overweight and obese pupils].

PubMed

Jodkowska, Maria; Oblacińska, Anna; Tabak, Izabela; Radiukiewicz, Katarzyna

2010-01-01

School-based physical education (PE) is often proposed as a strategy for obesity prevention and treatment. Thus the role of PE teachers is crucial on this field. The purpose of this study was to investigate the perception of PE teachers towards overweight and obese pupils aged 13-15 years, especially psychosomatic problems and support for obese adolescents in realisation of physical activity programme. A random sample of 185 PE teachers from 112 lower secondary schools in Poland were surveyed regarding their perception of pupils obesity and their support for obese adolescents. PE teachers observed many negative features among obese pupils: Two thirds of teachers (67% male and 74% teachers with work experience 6-10 years) observed decreased physical fitness and exercise capacity in this group of pupils. Body-related barriers in obese pupils and anxiety caused by weight related peer teasing were observed by respectively 30% and 20% teachers more often women teachers and teachers with shorter work experience. PE teachers were engaged in activities to support obese pupils: 90% of them assessed obese pupils by personal development, 70% conducted counseling and 20% cooperated with obese pupils' parents. Two third of teachers reported successes in their work with obese pupils. Their difficulties were connected with body-related barriers in pupils (24%), and aversion to exercise and physical efforts and location of PE lessons at school (9-16%). 1. The PE teachers can play an important role in preventing and combating obesity in pupils. 2. PE teachers should be motivated to organize interesting PE lessons, school sport and competitions for both normal and overweight pupils.

Special relativity and interferometers

NASA Technical Reports Server (NTRS)

Han, D.; Kim, Y. S.

1988-01-01

A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

Optically guided atom interferometer tuned to magic wavelength

NASA Astrophysics Data System (ADS)

Akatsuka, Tomoya; Takahashi, Tadahiro; Katori, Hidetoshi

2017-11-01

We demonstrate an atom interferometer operating on the 1S0-3P0 clock transition of 87Sr atoms in a “magic” optical guide, where the light shift perturbations of the guiding potential are canceled. As a proof-of-principle demonstration, a Mach-Zehnder interferometer is set horizontally to map the acceleration introduced by the focused optical guide. This magic guide interferometer on the clock transition is applicable to atomic elements where magic wavelengths can be found. Possible applications of the magic guide interferometer, including a hollow-core fiber interferometer and gradiometer, are discussed.

Ecological Condition of Streams in Northern Nevada EPA R-MAP Humboldt Basin Project

EPA Science Inventory

This report presents stream data on the Humboldt River Basin in northern Nevada using the R-EMAP Program. Water is of primary importance to both the economy and the ecology of the region. Many of the waters of Nevada have previously received relatively little attention in regar...

A Neural Theory of Visual Attention: Bridging Cognition and Neurophysiology

ERIC Educational Resources Information Center

Bundesen, Claus; Habekost, Thomas; Kyllingsbaek, Soren

2005-01-01

A neural theory of visual attention (NTVA) is presented. NTVA is a neural interpretation of C. Bundesen's (1990) theory of visual attention (TVA). In NTVA, visual processing capacity is distributed across stimuli by dynamic remapping of receptive fields of cortical cells such that more processing resources (cells) are devoted to behaviorally…

QUANTIFYING THE REGIONAL EFFECTS OF MINE DRAINAGE ON STREAM ECOLOGICAL CONDITION IN THE COLORADO ROCKIES FROM PROBABILITY SURVEY DATA

EPA Science Inventory

Runoff from both active and inactive metal mining has contaminated waters and sediments in the Southern Rockies Ecoregion. In 1994 and 1995, as part of its Regional Environmental Monitoring and Assessment Program (REMAP), the USEPA conducted a probability survey of wadeable stre...

A SMALL WATERSHED CHARACTERIZATION, CLASSIFICATION, AND ASSESSMENT FOR WEST VIRGINIA UTILIZING EMAP DESIGN AND TOOLS

EPA Science Inventory

A multi-objective sampling design has been implemented through R-EMAP support of a cooperative agreement with the state of West Virginia. Goals of the project include: 1) development and testing of a temperature-adjusted fish IBI for the Central Appalachian Plateau and Western Al...

IDENTIFICATION OF SPECIES-ENVIRONMENT RELATIONSHIPS IN THE HUDSON-RARITAN ESTUARY AND RELATED SUB-BASINS

EPA Science Inventory

The US EP A's Regional Environmental Monitoring and Assessment Program (REMAP) conducted a study in 1993/94 to assess the effects of sediment contamination in the Hudson- Raritan area (Upper New York, Raritan Bay, Jamaica Bay, western Long Island Sound and the Bight Apex). This s...

A COMPARATIVE ANALYSIS OF INDICES IN REMAP MONITORING STUDIES IN NEW YORK/NEW JERSEY HARBOR

EPA Science Inventory

Two regional monitoring efforts (1993/1994 and 1998) were conducted in the New York/New Jersey Harbor system. U.S. EPA-Region II (Edison, New Jersey) sought to evaluate the condition of the Harbor sediments and the changes over time as part of the Regional Environmental Monitor...

The Role of Somatosensory Information in Speech Perception: Imitation Improves Recognition of Disordered Speech

ERIC Educational Resources Information Center

Borrie, Stephanie A.; Schäfer, Martina C. M.

2015-01-01

Purpose: Perceptual learning paradigms involving written feedback appear to be a viable clinical tool to reduce the intelligibility burden of dysarthria. The underlying theoretical assumption is that pairing the degraded acoustics with the intended lexical targets facilitates a remapping of existing mental representations in the lexicon. This…

Absolute Pitch in Boreal Chickadees and Humans: Exceptions that Test a Phylogenetic Rule

ERIC Educational Resources Information Center

Weisman, Ronald G.; Balkwill, Laura-Lee; Hoeschele, Marisa; Moscicki, Michele K.; Bloomfield, Laurie L.; Sturdy, Christopher B.

2010-01-01

This research examined generality of the phylogenetic rule that birds discriminate frequency ranges more accurately than mammals. Human absolute pitch chroma possessors accurately tracked transitions between frequency ranges. Independent tests showed that they used note naming (pitch chroma) to remap the tones into ranges; neither possessors nor…

Speech Rate Normalization and Phonemic Boundary Perception in Cochlear-Implant Users

ERIC Educational Resources Information Center

Jaekel, Brittany N.; Newman, Rochelle S.; Goupell, Matthew J.

2017-01-01

Purpose: Normal-hearing (NH) listeners rate normalize, temporarily remapping phonemic category boundaries to account for a talker's speech rate. It is unknown if adults who use auditory prostheses called cochlear implants (CI) can rate normalize, as CIs transmit degraded speech signals to the auditory nerve. Ineffective adjustment to rate…

EVERGLADES ECOSYSTEM ASSESSMENT: WATER MANAGEMENT AND QUALITY, EUTROPHICATION, MERCURY CONTAMINATION, SOILS AND HABITAT: MONITORING FOR ADAPTIVE MANAGEMENT: A R-EMAP STATUS REPORT

EPA Science Inventory

The United States Environmental Protection Agency’s Everglades Ecosystem Assessment Program is a long-term research, monitoring and assessment effort. Its goal is to provide critical, timely, scientific information needed for management decisions on the Everglades ecosystem and i...

Ecological Condition of Streams in Eastern and Southern NevadaEPA R-EMAP Muddy-Virgin River Project

EPA Science Inventory

The report presents data collected during a one year study period beginning in May of 2000. Sampling sites were selected using a probability-based design (as opposed to subjectively selected sites) using the USEPA River Reach File version 3 (RF3). About 37 sites were sampled. ...

Visual attention and stability

PubMed Central

Mathôt, Sebastiaan; Theeuwes, Jan

2011-01-01

In the present review, we address the relationship between attention and visual stability. Even though with each eye, head and body movement the retinal image changes dramatically, we perceive the world as stable and are able to perform visually guided actions. However, visual stability is not as complete as introspection would lead us to believe. We attend to only a few items at a time and stability is maintained only for those items. There appear to be two distinct mechanisms underlying visual stability. The first is a passive mechanism: the visual system assumes the world to be stable, unless there is a clear discrepancy between the pre- and post-saccadic image of the region surrounding the saccade target. This is related to the pre-saccadic shift of attention, which allows for an accurate preview of the saccade target. The second is an active mechanism: information about attended objects is remapped within retinotopic maps to compensate for eye movements. The locus of attention itself, which is also characterized by localized retinotopic activity, is remapped as well. We conclude that visual attention is crucial in our perception of a stable world. PMID:21242140

Image splitting and remapping method for radiological image compression

NASA Astrophysics Data System (ADS)

Lo, Shih-Chung B.; Shen, Ellen L.; Mun, Seong K.

1990-07-01

A new decomposition method using image splitting and gray-level remapping has been proposed for image compression, particularly for images with high contrast resolution. The effects of this method are especially evident in our radiological image compression study. In our experiments, we tested the impact of this decomposition method on image compression by employing it with two coding techniques on a set of clinically used CT images and several laser film digitized chest radiographs. One of the compression techniques used was full-frame bit-allocation in the discrete cosine transform domain, which has been proven to be an effective technique for radiological image compression. The other compression technique used was vector quantization with pruned tree-structured encoding, which through recent research has also been found to produce a low mean-square-error and a high compression ratio. The parameters we used in this study were mean-square-error and the bit rate required for the compressed file. In addition to these parameters, the difference between the original and reconstructed images will be presented so that the specific artifacts generated by both techniques can be discerned by visual perception.

Automatic coronary artery segmentation based on multi-domains remapping and quantile regression in angiographies.

PubMed

Li, Zhixun; Zhang, Yingtao; Gong, Huiling; Li, Weimin; Tang, Xianglong

2016-12-01

Coronary artery disease has become the most dangerous diseases to human life. And coronary artery segmentation is the basis of computer aided diagnosis and analysis. Existing segmentation methods are difficult to handle the complex vascular texture due to the projective nature in conventional coronary angiography. Due to large amount of data and complex vascular shapes, any manual annotation has become increasingly unrealistic. A fully automatic segmentation method is necessary in clinic practice. In this work, we study a method based on reliable boundaries via multi-domains remapping and robust discrepancy correction via distance balance and quantile regression for automatic coronary artery segmentation of angiography images. The proposed method can not only segment overlapping vascular structures robustly, but also achieve good performance in low contrast regions. The effectiveness of our approach is demonstrated on a variety of coronary blood vessels compared with the existing methods. The overall segmentation performances si, fnvf, fvpf and tpvf were 95.135%, 3.733%, 6.113%, 96.268%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Fast algorithm of low power image reformation for OLED display

NASA Astrophysics Data System (ADS)

Lee, Myungwoo; Kim, Taewhan

2014-04-01

We propose a fast algorithm of low-power image reformation for organic light-emitting diode (OLED) display. The proposed algorithm scales the image histogram in a way to reduce power consumption in OLED display by remapping the gray levels of the pixels in the image based on the fast analysis of the histogram of the input image while maintaining contrast of the image. The key idea is that a large number of gray levels are never used in the images and these gray levels can be effectively exploited to reduce power consumption. On the other hand, to maintain the image contrast the gray level remapping is performed by taking into account the object size in the image to which each gray level is applied, that is, reforming little for the gray levels in the objects of large size. Through experiments with 24 Kodak images, it is shown that our proposed algorithm is able to reduce the power consumption by 10% even with 9% contrast enhancement. Our algorithm runs in a linear time so that it can be applied to moving pictures with high resolution.

Remapping of the RP15 Locus for X-Linked Cone-Rod Degeneration to Xp11.4-p21.1, and Identification of a De Novo Insertion in the RPGR Exon ORF15

PubMed Central

Mears, Alan J.; Hiriyanna, Suja; Vervoort, Raf; Yashar, Beverly; Gieser, Linn; Fahrner, Stacey; Daiger, Stephen P.; Heckenlively, John R.; Sieving, Paul A.; Wright, Alan F.; Swaroop, Anand

2000-01-01

X-linked forms of retinitis pigmentosa (XLRP) are among the most severe, because of their early onset, often leading to significant vision loss before the 4th decade. Previously, the RP15 locus was assigned to Xp22, by linkage analysis of a single pedigree with “X-linked dominant cone-rod degeneration.” After clinical reevaluation of a female in this pedigree identified her as affected, we remapped the disease to a 19.5-cM interval (DXS1219–DXS993) at Xp11.4-p21.1. This new interval overlapped both RP3 (RPGR) and COD1. Sequencing of the previously published exons of RPGR revealed no mutations, but a de novo insertion was detected in the new RPGR exon, ORF15. The identification of an RPGR mutation in a family with a severe form of cone and rod degeneration suggests that RPGR mutations may encompass a broader phenotypic spectrum than has previously been recognized in “typical” retinitis pigmentosa. PMID:10970770

It feels like it’s me: interpersonal multisensory stimulation enhances visual remapping of touch from other to self

PubMed Central

Cardini, Flavia; Tajadura-Jiménez, Ana; Serino, Andrea; Tsakiris, Manos

2013-01-01

Understanding other people’s feelings in social interactions depends on the ability to map onto our body the sensory experiences we observed on other people’s bodies. It has been shown that the perception of tactile stimuli on the face is improved when concurrently viewing a face being touched. This Visual Remapping of Touch (VRT) is enhanced the more similar others are perceived to be to the self, and is strongest when viewing one’s face. Here, we ask whether altering self-other boundaries can in turn change the VRT effect. We used the enfacement illusion, which relies on synchronous interpersonal multisensory stimulation (IMS), to manipulate self-other boundaries. Following synchronous, but not asynchronous, IMS, the self-related enhancement of the VRT extended to the other individual. These findings suggest that shared multisensory experiences represent one key way to overcome the boundaries between self and others, as evidenced by changes in somatosensory processing of tactile stimuli on one’s own face when concurrently viewing another person’s face being touched. PMID:23276110

New Techniques of Difference: On Data as School Pupils

ERIC Educational Resources Information Center

Thoutenhoofd, Ernst D.

2017-01-01

Pupils--the learners of both educational thought and of educational practice--exist ever more as data, as do the strictures and goals through which these pupils are pedagogically managed. I elaborate this thought by way of a single example: a particular kind of pupils whose number is reportedly on the increase, namely pupils diagnosed with…

Pupil Mobility, Attainment, and Progress during Key Stage 1: A Study in Cautious Interpretation.

ERIC Educational Resources Information Center

Strand, Steve

2002-01-01

Explores association between pupil mobility and attainment in national end of Key Stage 1 tests for 6000+ pupils in an English urban education authority. Indicates pupil mobility during the early years is associated with significantly lower levels of pupil attainment in reading, writing, and mathematics tests at age seven. (BT)

Issues Involved in Attempting to Develop Independent Learning in Pupils Working on Technological Projects

ERIC Educational Resources Information Center

Barak, Moshe

2004-01-01

This research addresses the impact of technological projects at high school on pupils' learning. The participants were sixty low-mid achieving pupils who worked for one year on final projects for matriculation exams. Data were collected through observations of laboratory lessons, interviews with pupils and teachers, and analysis of pupils'…

Pupil size reflects successful encoding and recall of memory in humans.

PubMed

Kucewicz, Michal T; Dolezal, Jaromir; Kremen, Vaclav; Berry, Brent M; Miller, Laura R; Magee, Abigail L; Fabian, Vratislav; Worrell, Gregory A

2018-03-21

Pupil responses are known to indicate brain processes involved in perception, attention and decision-making. They can provide an accessible biomarker of human memory performance and cognitive states in general. Here we investigated changes in the pupil size during encoding and recall of word lists. Consistent patterns in the pupil response were found across and within distinct phases of the free recall task. The pupil was most constricted in the initial fixation phase and was gradually more dilated through the subsequent encoding, distractor and recall phases of the task, as the word items were maintained in memory. Within the final recall phase, retrieving memory for individual words was associated with pupil dilation in absence of visual stimulation. Words that were successfully recalled showed significant differences in pupil response during their encoding compared to those that were forgotten - the pupil was more constricted before and more dilated after the onset of word presentation. Our results suggest pupil size as a potential biomarker for probing and modulation of memory processing.

Eye pupil detection system using an ensemble of regression forest and fast radial symmetry transform with a near infrared camera

NASA Astrophysics Data System (ADS)

Jeong, Mira; Nam, Jae-Yeal; Ko, Byoung Chul

2017-09-01

In this paper, we focus on pupil center detection in various video sequences that include head poses and changes in illumination. To detect the pupil center, we first find four eye landmarks in each eye by using cascade local regression based on a regression forest. Based on the rough location of the pupil, a fast radial symmetric transform is applied using the previously found pupil location to rearrange the fine pupil center. As the final step, the pupil displacement is estimated between the previous frame and the current frame to maintain the level of accuracy against a false locating result occurring in a particular frame. We generated a new face dataset, called Keimyung University pupil detection (KMUPD), with infrared camera. The proposed method was successfully applied to the KMUPD dataset, and the results indicate that its pupil center detection capability is better than that of other methods and with a shorter processing time.

Comparison of Atom Interferometers and Light Interferometers as Space-Based Gravitational Wave Detectors

NASA Technical Reports Server (NTRS)

Baker, John G.

2012-01-01

We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

Comparison of atom interferometers and light interferometers as space-based gravitational wave detectors.

PubMed

Baker, John G; Thorpe, J I

2012-05-25

We consider a class of proposed gravitational-wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, noninertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g., multiple-arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and, in principle, favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

Keeping an eye on the truth? Pupil size changes associated with recognition memory.

PubMed

Heaver, Becky; Hutton, Sam B

2011-05-01

During recognition memory tests participants' pupils dilate more when they view old items compared to novel items. We sought to replicate this "pupil old/new effect" and to determine its relationship to participants' responses. We compared changes in pupil size during recognition when participants were given standard recognition memory instructions, instructions to feign amnesia, and instructions to report all items as new. Participants' pupils dilated more to old items compared to new items under all three instruction conditions. This finding suggests that the increase in pupil size that occurs when participants encounter previously studied items is not under conscious control. Given that pupil size can be reliably and simply measured, the pupil old/new effect may have potential in clinical settings as a means for determining whether patients are feigning memory loss.

Analysis of various factors affecting pupil size in patients with glaucoma.

PubMed

Park, Ji Woong; Kang, Bong Hui; Kwon, Ji Won; Cho, Kyong Jin

2017-09-16

Pupil size is an important factor in predicting post-operative satisfaction. We assessed the correlation between pupil size, measured by Humphrey static perimetry, and various affecting factors in patients with glaucoma. In total, 825 eyes of 415 patients were evaluated retrospectively. Pupil size was measured with Humphrey static perimetry. Comparisons of pupil size according to the presence of glaucoma were evaluated, as were correlations between pupil size and various factors, including age, logMAR best corrected visual acuity (BCVA), retinal nerve fiber layer (RNFL) thickness, spherical equivalent, intraocular pressure, axial length, central corneal thickness, white-to-white, and the kappa angle. Pupil size was significantly smaller in glaucoma patients than in glaucoma suspects (p < 0.001) or the normal group (p < 0.001). Pupil size decreased significantly as age (p < 0.001) and central cornea thickness (p = 0.007) increased, and increased significantly as logMAR BCVA (p = 0.02) became worse and spherical equivalent (p = 0.007) and RNFL thickness (p = 0.042) increased. In patients older than 50 years, pupil size was significantly larger in eyes with a history of cataract surgery. Humphrey static perimetry can be useful in measuring pupil size. Pupil size was significantly smaller in eyes with glaucoma. Other factors affecting pupil size can be used in a preoperative evaluation when considering cataract surgery or laser refractive surgery.

Pupil Alignment Considerations for Large, Deployable Space Telescopes

NASA Technical Reports Server (NTRS)

Bos, Brent J.; Ohl, Raymond G.; Kubalak, Daivd A.

2011-01-01

For many optical systems the properties and alignment of the internal apertures and pupils are not critical or controlled with high precision during optical system design, fabrication or assembly. In wide angle imaging systems, for instance, the entrance pupil position and orientation is typically unconstrained and varies over the system s field of view in order to optimize image quality. Aperture tolerances usually do not receive the same amount of scrutiny as optical surface aberrations or throughput characteristics because performance degradation is typically graceful with misalignment, generally only causing a slight reduction in system sensitivity due to vignetting. But for a large deployable space-based observatory like the James Webb Space Telescope (JWST), we have found that pupil alignment is a key parameter. For in addition to vignetting, JWST pupil errors cause uncertainty in the wavefront sensing process that is used to construct the observatory on-orbit. Furthermore they also open stray light paths that degrade the science return from some of the telescope s instrument channels. In response to these consequences, we have developed several pupil measurement techniques for the cryogenic vacuum test where JWST science instrument pupil alignment is verified. These approaches use pupil alignment references within the JWST science instruments; pupil imaging lenses in three science instrument channels; and unique pupil characterization features in the optical test equipment. This will allow us to verify and crosscheck the lateral pupil alignment of the JWST science instruments to approximately 1-2% of their pupil diameters.

Construction of the first genetic linkage map of Japanese gentian (Gentianaceae)

PubMed Central

2012-01-01

Background Japanese gentians (Gentiana triflora and Gentiana scabra) are amongst the most popular floricultural plants in Japan. However, genomic resources for Japanese gentians have not yet been developed, mainly because of the heterozygous genome structure conserved by outcrossing, the long juvenile period, and limited knowledge about the inheritance of important traits. In this study, we developed a genetic linkage map to improve breeding programs of Japanese gentians. Results Enriched simple sequence repeat (SSR) libraries from a G. triflora double haploid line yielded almost 20,000 clones using 454 pyrosequencing technology, 6.7% of which could be used to design SSR markers. To increase the number of molecular markers, we identified three putative long terminal repeat (LTR) sequences using the recently developed inter-primer binding site (iPBS) method. We also developed retrotransposon microsatellite amplified polymorphism (REMAP) markers combining retrotransposon and inter-simple sequence repeat (ISSR) markers. In addition to SSR and REMAP markers, modified amplified fragment length polymorphism (AFLP) and random amplification polymorphic DNA (RAPD) markers were developed. Using 93 BC1 progeny from G. scabra backcrossed with a G. triflora double haploid line, 19 linkage groups were constructed with a total of 263 markers (97 SSR, 97 AFLP, 39 RAPD, and 30 REMAP markers). One phenotypic trait (stem color) and 10 functional markers related to genes controlling flower color, flowering time and cold tolerance were assigned to the linkage map, confirming its utility. Conclusions This is the first reported genetic linkage map for Japanese gentians and for any species belonging to the family Gentianaceae. As demonstrated by mapping of functional markers and the stem color trait, our results will help to explain the genetic basis of agronomic important traits, and will be useful for marker-assisted selection in gentian breeding programs. Our map will also be an important resource for further genetic analyses such as mapping of quantitative trait loci and map-based cloning of genes in this species. PMID:23186361

Time Is Not Space: Core Computations and Domain-Specific Networks for Mental Travels.

PubMed

Gauthier, Baptiste; van Wassenhove, Virginie

2016-11-23

Humans can consciously project themselves in the future and imagine themselves at different places. Do mental time travel and mental space navigation abilities share common cognitive and neural mechanisms? To test this, we recorded fMRI while participants mentally projected themselves in time or in space (e.g., 9 years ago, in Paris) and ordered historical events from their mental perspective. Behavioral patterns were comparable for mental time and space and shaped by self-projection and by the distance of historical events to the mental position of the self, suggesting the existence of egocentric mapping in both dimensions. Nonetheless, self-projection in space engaged the medial and lateral parietal cortices, whereas self-projection in time engaged a widespread parietofrontal network. Moreover, while a large distributed network was found for spatial distances, temporal distances specifically engaged the right inferior parietal cortex and the anterior insula. Across these networks, a robust overlap was only found in a small region of the inferior parietal lobe, adding evidence for its role in domain-general egocentric mapping. Our findings suggest that mental travel in time or space capitalizes on egocentric remapping and on distance computation, which are implemented in distinct dimension-specific cortical networks converging in inferior parietal lobe. As humans, we can consciously imagine ourselves at a different time (mental time travel) or at a different place (mental space navigation). Are such abilities domain-general, or are the temporal and spatial dimensions of our conscious experience separable? Here, we tested the hypothesis that mental time travel and mental space navigation required the egocentric remapping of events, including the estimation of their distances to the self. We report that, although both remapping and distance computation are foundational for the processing of the temporal and spatial dimensions of our conscious experience, their neuroanatomical implementations were clearly dissociable and engaged distinct parietal and parietofrontal networks for mental space navigation and mental time travel, respectively. Copyright © 2016 the authors 0270-6474/16/3611891-13$15.00/0.

Assessment Accommodations for Foreign Pupils in the Light of Educational Justice: Empirical Research among Slovenian Primary School Teachers

ERIC Educational Resources Information Center

Mihelic, Mojca Žveglic

2017-01-01

The starting points of primary school pupils in a foreign country differ significantly from those of native pupils. In Slovenia, the knowledge of pupils who are foreign citizens (foreign pupils) may be assessed with different accommodations for no more than two years. The presented research conducted on a representative sample of 697 Slovenian…

Scientific Literacy, E-Literacy and Illiteracy: The Interaction between Two Pupils and One Simulation

ERIC Educational Resources Information Center

McLuckie, Joe; Rodrigues, Susan; Taylor, Neil; Williamson, Graham

2007-01-01

This paper explores the influence of symbolic or representational learning materials on pupil engagement or learning outcomes, when 14-16 year old pupils use common types of science simulations. The project pilot phase involved three (15-16 year old) male pupils and a main phase involved twenty-one (14-15 year old) pupils. A retrospective accounts…

Teachers on Perceived Traits and Academic Achievements of Regular Pupils and Pupils with Special Needs in Mainstream Primary Schools

ERIC Educational Resources Information Center

Lesar, Irena; Cuk, Ivan; Pecek, Mojca

2014-01-01

When looking for answers to the question of academic (non)achievement of regular pupils and pupils with special needs, it is necessary to take into account the extraordinary complexity of factors, ranging from psychological across instructional to home environment variables. The academic achievement is not only a reflection of the pupil's…

Ethnic School Segregation and Self-Esteem: The Role of Teacher-Pupil Relationships

ERIC Educational Resources Information Center

Agirdag, Orhan; Van Houtte, Mieke; Van Avermaet, Piet

2012-01-01

The authors examine whether school segregation is related to pupils' global self-esteem and whether this association is mediated by teacher-pupil relationships. Multilevel analyses based on a survey of 2,845 pupils (aged 10 to 12) in 68 primary schools in Belgian urban areas reveal that, for native-Belgian pupils, a higher proportion of immigrants…

Mesopic pupil size in a refractive surgery population (13,959 eyes).

PubMed

Linke, Stephan J; Baviera, Julio; Munzer, Gur; Fricke, Otto H; Richard, Gisbert; Katz, Toam

2012-08-01

To evaluate factors that may affect mesopic pupil size in refractive surgery candidates. Medical records of 13,959 eyes of 13,959 refractive surgery candidates were reviewed, and one eye per subject was selected randomly for statistical analysis. Detailed ophthalmological examination data were obtained from medical records. Preoperative measurements included uncorrected distance visual acuity, corrected distance visual acuity, manifest and cycloplegic refraction, topography, slit lamp examination, and funduscopy. Mesopic pupil size measurements were performed with Colvard pupillometer. Relationship between mesopic pupil size and age, gender, refractive state, average keratometry, and pachymetry (thinnest point) were analyzed by means of ANOVA (+ANCOVA) and multivariate regression analyses. Overall mesopic pupil size was 6.45 ± 0.82 mm, and mean age was 36.07 years. Mesopic pupil size was 5.96 ± 0.8 mm in hyperopic astigmatism, 6.36 ± 0.83 mm in high astigmatism, and 6.51 ± 0.8 mm in myopic astigmatism. The difference in mesopic pupil size between all refractive subgroups was statistically significant (p < 0.001). Age revealed the strongest correlation (r = -0.405, p < 0.001) with mesopic pupil size. Spherical equivalent showed a moderate correlation (r = -0.136), whereas keratometry (r = -0.064) and pachymetry (r = -0.057) had a weak correlation with mesopic pupil size. No statistically significant difference in mesopic pupil size was noted regarding gender and ocular side. The sum of all analyzed factors (age, refractive state, keratometry, and pachymetry) can only predict the expected pupil size in <20% (R = 0.179, p < 0.001). Our analysis confirmed that age and refractive state are determinative factors on mesopic pupil size. Average keratometry and minimal pachymetry exhibited a statistically significant, but clinically insignificant, impact on mesopic pupil size.

Efficacy of the Canabrava Ring (pupil expansion device) in cataract surgery for eyes with small pupils: the first 30 cases.

PubMed

Canabrava, Sérgio; Rezende, Pedro Henriques; Eliazar, Glauber Coutinho; Figueiredo, Sophia Barbosa de; Resende, Arthur Fernandes; Batista, Wagner Duarte; Diniz-Filho, Alberto

2018-06-01

To evaluate the outcomes of the first 30 cataract surgeries performed with a new disposable, injector-free, small-pupil expansion device. This consecutive case series included 30 eyes from 29 patients who underwent cataract surgery using a new disposable small-pupil expansion device called the Canabrava Ring (AJL Ophthalmic S.A, Spain). It is the first iris expansion ring produced with indents that do not align with each other in the superior and inferior regions, resulting in a small vertical length (0.4 mm) that minimizes the risk of endothelial contact. All eyes had poorly dilated pupils of less than 5 mm preoperatively. Fifteen eyes had significant infective or traumatic pathologies preoperatively. Vertical and horizontal pupil diameters were evaluated preoperatively, intraoperatively, and 1 month postoperatively. The mean patient age was 64 ± 11.8 (standard deviation) years. The Canabrava Ring remained engaged throughout all surgeries, except one. All pupils were intraoperatively expanded to a diameter of 6.3 mm. Although preexisting pathology on the innervation of the pupils, the mean pupil diameter returns to a close preoperative size after 1 month surgery. The mean pupil diameters postoperatively and preoperatively were 4.41 and 3.77 mm, respectively (p<0.05). Postoperative complications occurred in eight eyes (one toxoplasmosis reactivation, one retinal detachment, one posterior capsule rupture, one posterior capsule opacification, and four posterior synechiae). These complications occurred in eyes with preexisting traumatic or infective pathologies or synechiae. The Canabrava Ring is effective for expanding and maintaining expansion of small pupils in cataract surgery. The increase in postoperative pupil diameter is clinically diminutive and can most likely be attributed to preexisting pathologies affecting pupil innervation. Further large-scale studies are required to support the present findings.

The Mask Designs for Space Interferometer Mission (SIM)

NASA Technical Reports Server (NTRS)

Wang, Xu

2008-01-01

The Space Interferometer Mission (SIM) consists of three interferometers (science, guide1, and guide2) and two optical paths (metrology and starlight). The system requirements for each interferometer/optical path combination are different and sometimes work against each other. A diffraction model is developed to design and optimize various masks to simultaneously meet the system requirements of three interferometers. In this paper, the details of this diffraction model will be described first. Later, the mask design for each interferometer will be presented to demonstrate the system performance compliance. In the end, a tolerance sensitivity study on the geometrical dimension, shape, and the alignment of these masks will be discussed.

Modulated Source Interferometry with Combined Amplitude and Frequency Modulation

NASA Technical Reports Server (NTRS)

Gutierrez, Roman C. (Inventor)

1998-01-01

An improved interferometer is produced by modifying a conventional interferometer to include amplitude and/or frequency modulation of a coherent light source at radio or higher frequencies. The phase of the modulation signal can be detected in an interfering beam from an interferometer and can be used to determine the actual optical phase of the beam. As such, this improvement can be adapted to virtually any two-beam interferometer, including: Michelson, Mach-Zehnder, and Sagnac interferometers. The use of an amplitude modulated coherent tight source results in an interferometer that combines the wide range advantages of coherent interferometry with the precise distance measurement advantages of white light interferometry.

Comparison of the performance of the next generation of optical interferometers

NASA Astrophysics Data System (ADS)

Pisani, Marco; Yacoot, Andrew; Balling, Petr; Bancone, Nicola; Birlikseven, Cengiz; Çelik, Mehmet; Flügge, Jens; Hamid, Ramiz; Köchert, Paul; Kren, Petr; Kuetgens, Ulrich; Lassila, Antti; Bartolo Picotto, Gian; Şahin, Ersoy; Seppä, Jeremias; Tedaldi, Matthew; Weichert, Christoph

2012-08-01

Six European National Measurement Institutes (NMIs) have joined forces within the European Metrology Research Programme funded project NANOTRACE to develop the next generation of optical interferometers having a target uncertainty of 10 pm. These are needed for NMIs to provide improved traceable dimensional metrology that can be disseminated to the wider nanotechnology community, thereby supporting the growth in nanotechnology. Several approaches were followed in order to develop the interferometers. This paper briefly describes the different interferometers developed by the various partners and presents the results of a comparison of performance of the optical interferometers using an x-ray interferometer to generate traceable reference displacements.

A novel plane mirror interferometer without using corner cube reflectors

NASA Astrophysics Data System (ADS)

Büchner, H.-J.; Jäger, G.

2006-04-01

The conception and properties will be introduced of an interferometer that exclusively uses plane mirrors as reflectors; thus, these interferometers correspond well to the original Michelson interferometer. First, the relationship between the interference conditions and the detection with photodiodes will be discussed using the example of known interferometers as well as reasons given for primarily using corner cube reflectors in these devices. Next, the conceptual design of the plane mirror interferometer will be presented. This type of interferometer possesses new properties which are significant for metrological and technical applications. Only one measuring beam exists between the polarizing beam splitter and the measuring mirror and this beam alone represents the Abbe axis. This property allows the significant reduction of the Abbe error. The interferometer is able to tolerate tilting on the order of about 1'. This ensures the orthogonality between the measuring beam and the measuring mirror during the measurement. This property can be used in three-dimensional measurements to erect the three measuring beams as a x-y-z Cartesian coordinate system on the basis of three orthogonal mirrors. The plane-mirror interferometer also allows non-contact measurements of planar and curved surfaces, e.g. silicon wafers.

Pupil movements to light and accommodative stimulation - A comparative study.

NASA Technical Reports Server (NTRS)

Semmlow, J.; Stark, L.

1973-01-01

Isolation and definition of specific response components in pupil reflexes through comparison of the dynamic features of light-induced and accommodation-induced pupil movements. A quantitative analysis of the behavior of the complex nonlinear pupil responses reveals the presence of two independent nonlinear characteristics: a range-dependent gain and a direction dependence or movement asymmetry. These nonlinear properties are attributed to motor processes because they are observable in pupil responses to both light and accommodation stimuli. The possible mechanisms and consequences of these pupil response characteristics are quantitatively defined and discussed.

Microwave interferometer controls cutting depth of plastics

NASA Technical Reports Server (NTRS)

Heisman, R. M.; Iceland, W. F.

1969-01-01

Microwave interferometer system controls the cutting of plastic materials to a prescribed depth. The interferometer is mounted on a carriage with a spindle and cutting tool. A cross slide, mounted on the carriage, allows the interferometer and cutter to move toward or away from the plastic workpiece.

Absolute metrology for space interferometers

NASA Astrophysics Data System (ADS)

Salvadé, Yves; Courteville, Alain; Dändliker, René

2017-11-01

The crucial issue of space-based interferometers is the laser interferometric metrology systems to monitor with very high accuracy optical path differences. Although classical high-resolution laser interferometers using a single wavelength are well developed, this type of incremental interferometer has a severe drawback: any interruption of the interferometer signal results in the loss of the zero reference, which requires a new calibration, starting at zero optical path difference. We propose in this paper an absolute metrology system based on multiplewavelength interferometry.

Improvement of unbalanced illumination induced telecentricity within the exposure slit

NASA Astrophysics Data System (ADS)

Jang, Jonghoon; Lee, ByeongSoo; Kang, Young Seog; Chang, Chansam; Kong, Jeong-Heung; Kim, Young Ha; Bouman, Wim; de Graaf, Roelof; Weichselbaum, Stefan; Droste, Richard; de Boeij, Wim P.; van Bussel, Bart; Neefs, Patrick; Rijke, Arij

2016-03-01

Adjustment and control of the illumination pupil asymmetry is relevant for wafer alignment and overlay of lithography tools. Pupil asymmetries can cause a tilt in aerial image (Aerial Image Tilt, or AIT). This AIT, combined with a focus offset, leads to a horizontal image shift. Pupil asymmetries can be related to a shift of the entire illumination pupil (geometrical telecentricity) caused by illuminator misalign. Another type of pupil asymmetry is energetic imbalance (quantified by pupil Center of Gravity, COG). The scanner can show pupil variation across the exposure slit. In general the COG at the edge of the slit is often worse than in the center part of the slit. Recently, ASML has released the NXT:1980Di that is equipped with an enhanced illuminator to improve pupil COG variation across the slit. In this paper we explore the performance of this scanner system and show that the AIT variation across the slit is also reduced significantly.

Programmable Spectral Source and Design Tool for 3D Imaging Using Complementary Bandpass Filters

NASA Technical Reports Server (NTRS)

Bae, Youngsam (Inventor); Korniski, Ronald J. (Inventor); Ream, Allen (Inventor); Shearn, Michael J. (Inventor); Shahinian, Hrayr Karnig (Inventor); Fritz, Eric W. (Inventor)

2017-01-01

An endoscopic illumination system for illuminating a subject for stereoscopic image capture, includes a light source which outputs light; a first complementary multiband bandpass filter (CMBF) and a second CMBF, the first and second CMBFs being situated in first and second light paths, respectively, where the first CMBF and the second CMBF filter the light incident thereupon to output filtered light; and a camera which captures video images of the subject and generates corresponding video information, the camera receiving light reflected from the subject and passing through a pupil CMBF pair and a detection lens. The pupil CMBF includes a first pupil CMBF and a second pupil CMBF, the first pupil CMBF being identical to the first CMBF and the second pupil CMBF being identical to the second CMBF, and the detection lens includes one unpartitioned section that covers both the first pupil CMBF and the second pupil CMBF.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

The optical configuration of a Fabry-Perot interferometer is uncomplicated. This has already been applied in different measurement systems. For the displacement measurement with the Fabry-Perot interferometer, the result is significantly influenced by the tilt angles of the measurement mirror in the interferometer. Hence, only for the rather small measuring range, the Fabry-Perot interferometer is available. The goal of this investigation is to enhance the measuring range of Fabry-Perot interferometer by compensating the tilt angles. To verify the measuring characteristic of the self-developed Fabry-Perot interferometer, some comparison measurements with a reference standard have been performed. The maximum deviation of comparison experimentsmore » is less than 0.3 {mu}m in the traveling range of 30 mm. The experimental results show that the Fabry-Perot interferometer is highly stable, insensitive to environment effects, and can meet the measuring requirement of the submicrometer order.« less

Solar Confocal interferometers for Sub-Picometer-Resolution Spectral Filters

NASA Technical Reports Server (NTRS)

Gary, G. Allen; Pietraszewski, Chris; West, Edward A.; Dines. Terence C.

2007-01-01

The confocal Fabry-Perot interferometer allows sub-picometer spectral resolution of Fraunhofer line profiles. Such high spectral resolution is needed to keep pace with the higher spatial resolution of the new set of large-aperture solar telescopes. The line-of-sight spatial resolution derived for line profile inversions would then track the improvements of the transverse spatial scale provided by the larger apertures. In particular, profile inversion allows improved velocity and magnetic field gradients to be determined independent of multiple line analysis using different energy levels and ions. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. The higher throughput for the interferometer provides significant decrease in the aperture, which is important in spaceflight considerations. We have constructed and tested two confocal interferometers. A slow-response thermal-controlled interferometer provides a stable system for laboratory investigation, while a piezoelectric interferometer provides a rapid response for solar observations. In this paper we provide design parameters, show construction details, and report on the laboratory test for these interferometers. The field of view versus aperture for confocal interferometers is compared with other types of spectral imaging filters. We propose a multiple etalon system for observing with these units using existing planar interferometers as pre-filters. The radiometry for these tests established that high spectral resolution profiles can be obtained with imaging confocal interferometers. These sub-picometer spectral data of the photosphere in both the visible and near-infrared can provide important height variation information. However, at the diffraction-limited spatial resolution of the telescope, the spectral data is photon starved due to the decreased spectral passband.

An Exploratory Study on How Primary Pupils Approach Systems

ERIC Educational Resources Information Center

Koski, Marja-Ilona; de Vries, Marc

2013-01-01

This paper presents a study of systems thinking among 27 primary pupils (8-10 years old) and their teacher. The study included a pre-test for the teacher and the pupils, lesson planning, the actual lesson and a post-test for the pupils. The research focused on finding an answer to three questions: (1) do pupils see a system as a structure…

Cooking and Hammering: Primary School Pupils' Concepts of Their Craft Skills

ERIC Educational Resources Information Center

Müürsepp, Mare; Kikkull, Andry

2014-01-01

The aim of the study is to clear the significance of craft skills for the pupils in age nine and twelve years. More than 200 pupils were asked to define, what are the most important skills for the pupils of their age. The results bring out that category of the skills related to craft subject is of the most presented categories in pupils' self…

School and Pupil Effects on Secondary Pupils' Feelings of Safety in School, around School, and at Home

ERIC Educational Resources Information Center

Mooij, Ton; Fettelaar, Daan

2013-01-01

In line with fear of crime research, schools should be secure places where pupils feel safe in order to function well. Various types of risk and promotive variables at school and pupil level may differently influence a pupil's feelings of safety in school, the school surroundings, and at home. The aim is to elaborate and test a theoretical…

Pupils as Active Participants: Diamond Ranking as a Tool to Investigate Pupils' Experiences of Classroom Practices

ERIC Educational Resources Information Center

Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse

2015-01-01

This article is based on a pedagogical action research initiative carried out in a Finnish primary school. Twenty-four 5th grade pupils and their teacher participated in the study. The research initiative was guided by two questions: (1) How do pupils experience their classroom practices? (2) How can pupils participate in the process of developing…

Optica aperture synthesis

NASA Astrophysics Data System (ADS)

van der Avoort, Casper

2006-05-01

Optical long baseline stellar interferometry is an observational technique in astronomy that already exists for over a century, but is truly blooming during the last decades. The undoubted value of stellar interferometry as a technique to measure stellar parameters beyond the classical resolution limit is more and more spreading to the regime of synthesis imaging. With optical aperture synthesis imaging, the measurement of parameters is extended to the reconstruction of high resolution stellar images. A number of optical telescope arrays for synthesis imaging are operational on Earth, while space-based telescope arrays are being designed. For all imaging arrays, the combination of the light collected by the telescopes in the array can be performed in a number of ways. In this thesis, methods are introduced to model these methods of beam combination and compare their effectiveness in the generation of data to be used to reconstruct the image of a stellar object. One of these methods of beam combination is to be applied in a future space telescope. The European Space Agency is developing a mission that can valuably be extended with an imaging beam combiner. This mission is labeled Darwin, as its main goal is to provide information on the origin of life. The primary objective is the detection of planets around nearby stars - called exoplanets- and more precisely, Earth-like exoplanets. This detection is based on a signal, rather than an image. With an imaging mode, designed as described in this thesis, Darwin can make images of, for example, the planetary system to which the detected exoplanet belongs or, as another example, of the dust disk around a star out of which planets form. Such images will greatly contribute to the understanding of the formation of our own planetary system and of how and when life became possible on Earth. The comparison of beam combination methods for interferometric imaging occupies most of the pages of this thesis. Additional chapters will treat related subjects, being experimental work on beam combination optics, a description of a novel formalism for aberration retrieval and experimental work on nulling interferometry. The Chapters on interferometric imaging are organized in such a way that not only the physical principles behind a stellar interferometer are clear, but these chapters also form a basis for the method of analysis applied to the interferometers - -or rather beam combination methods- under consideration. The imaging process in a stellar interferometer will be treated as the inversion of a linear system of equations. The definition of interferometric imaging in this thesis can be stated to be the reconstruction of a luminosity distribution function on the sky, that is, in angular measure, larger than the angular diffraction limited spot size -or Point-Spread Function (PSF)- of a single telescope in the array and that contains, again in angular measure, spatial structure that is much smaller than the PSF of a single telescope. This reconstruction has to be based on knowledge of the dimensions of the telescope array and the detector. The detector collects intensity data that is formed by observation of the polychromatic luminosity distribution on the sky and is deteriorated by the quantum-nature of light and an imperfect electronic detection process. Therefore, the imaging study presented in this thesis can be regarded to be a study on the signal characteristics of various interferometers while imaging a polychromatic wide-field stellar source. The collection of beam combination methods under consideration consists of four types. Among these are two well-known types, having either co-axially combined beams as in the Michelson-Morley experiment to demonstrate the existence of ether, or beams that follow optical paths as if an aperture mask were placed in front of a telescope, making the beams combine in the focus of that telescope, as suggested by Fizeau. For separated apertures rather than an aperture mask, these optical paths are stated to be homothetic. In short, these two types will be addressed as the Michelson or the Homothetic type. The other two types are addressed as Densified and Staircase. The first one is short for densified pupil imaging, an imaging technique very similar to the Homothetic type, be it that the natural course of light after the aperture mask is altered. However, the combination of the beams of light is again in focus. The Staircase method is an alternative to the co-axial Michelson method and lends its name from the fact that a staircase-shaped mirror is placed in an intermediate focal plane after each telescope in the array, before combining the beams of light co-axially. This addition allows stellar imaging as with the Michelson type, with the advantage of covering a large field-of-view. The details of these methods will intensively be discussed in this thesis, but the introduction of them at this point allows a short list of results, found by comparing them for equal imaging tasks. Homothetic imagers are best suited for covering a wide field-of-view, considering the information content of the interferometric signals these arrays produce. The large number of detectors does not seem to limit the imaging performance in the presence of noise, due to the high ratio of coherent versus incoherent information in the detector signal. The imaging efficiency of a Michelson type array is also high, although -considering only polychromatic wide-field imaging tasks- the ratio of coherent versus incoherent information in the detected signals is very low. This results in very large observation times needed to produce images comparable to those obtained with a Homothetic array. A detailed presentation of the characteristics of the detected signals in a co-axial Michelson array reveal that such signals, obtained by polychromatic observation of extended sources, have fringe envelope functions that do not allow Fourier-spectroscopy to obtain high-resolution spectroscopic information about such a source. For the Densified case, it is found that this method can indeed provide an interferometric PSF that is more favorable than a homothetic PSF, but only for narrow-angle observations. For polychromatic wide-field observations, the Densified-PSF is field-dependent, for which the image reconstruction process can account. Wide-field imaging using the favorable properties of the Densified-PSF can be performed, by using special settings of the delay or optical path length difference between interferometer arms and including observations with several settings of delay in the observation data. The Staircase method is the second best method for the imaging task under consideration. The discontinuous nature of the staircase-shaped mirrors does not give rise to a discontinuous reconstructed luminosity distribution or non-uniformly covered spatial frequencies. The intrinsic efficiency of the interferometric signal in this type of interferometer is worse than that of the other co-axial method, although the ratio of coherent versus incoherent signal in the data -the length of the fringe packet in one intensity trace-e- is nearly ultimate. The inefficiency is overwhelmingly compensated for by the very short observation time needed. Besides numerical studies of interferometer arrays, one interferometric imager was also studied experimentally. A homothetic imager was built, comprising three telescopes with fully separated beam relay optics. The pointing direction, the location and the optical path length of two of the three beams are electronically controllable. The beams can be focused together to interfere, via a beam combiner consisting of curved surfaces. This set-up allows to measure the required accuracies at which certain optical elements have to be positioned. Moreover, this set-up demonstrates that without knowledge of the initial pointing directions, locations and optical path lengths of the beams, the situation of homothesis can be attained, solely based on information from the focal plane of the set-up. Further experiments show that the approximation of exact homothesis is limited by the optical quality of the beam combiner optics. Parallel to the experiments on homothesis, a study was performed to evaluate the use of the Extended Nijboer-Zernike (ENZ) formalism for analysis of multiple aperture optical systems. It is envisaged that an aberration retrieval algorithm, provided with the common focus of a homothetic array, can be used to detect misalignment of or even aberrations in the sub-apertures of the sparse synthetic aperture. The ENZ formalism is a powerful tool to describe the focal intensity profile in an optical imaging system, imaging a monochromatic point source through a pupil that is allowed to have a certain transmission profile and phase aberration function over the pupil. Moreover, the formalism allows calculation of intensity profiles outside the best-focus plane. With the intensity information of several through-focus planes, enough information is available to reconstruct the pupil function from it. The formalism is described, including the reconstruction algorithm. Although very good results are obtained for general pupil functions, the results for synthetic pupil functions are not very promising. The detailed description of the ENZ-aberration retrieval reveals the origin of the breakdown of the retrieval process. Finally, a description of experiments on nulling interferometry is given, starting with the presentation of an experimental set-up for three-beam nulling. A novel strategy for polychromatic nulling is treated here, with the goal of relieving the tight phase constraint on the spectra in the individual beams. This theoretically allows broad band-nulling with a high rejection ratio without using achromatic phase shifters. The disappointing results led to an investigation of the spectra of the individual beams. The origin of the unsatisfactory level of the rejection ratio is found in the spectral unbalance of the beams. Before branching off, the beams have an equal spectrum. Then, the encounter of different optical elements with individually applied coatings, the control of beam-power per beam and finally the beam coupling into a single-mode fiber, apparently alter the spectra in such a way that the theoretically achievable level of the rejection ratio cannot be reached. The research described in this thesis provides onsets for research in several areas of interest related to aperture synthesis and guidelines concerning the design of synthetic telescopes for imaging. As such, this research contributes to the improvement of instrumentation for observational astronomy, in particular for stellar interferometry. While nulling interferometry is the detection technique that allows a space telescope array such as ESA-Darwin to identify exoplanets, optical aperture synthesis imaging is the technique that can make images of the planetary systems to which these exoplanets belong. Moreover, many objects can be observed that represent earlier versions of our planetary system, our Sun and even our galaxy, the Milky Way. Observing these objects might answer questions about the origins of the Earth itself and the life on it.

Experimental investigations of pupil accommodation factors.

PubMed

Lee, Eui Chul; Lee, Ji Woo; Park, Kang Ryoung

2011-08-17

PURPOSE. The contraction and dilation of the iris muscle that controls the amount of light entering the retina causes pupil accommodation. In this study, experiments were performed and two of the three factors that influence pupil accommodation were analyzed: lighting conditions and depth fixations. The psychological benefits were not examined, because they could not be quantified. METHODS. A head-wearable eyeglasses-based, eye-capturing device was designed to measure pupil size. It included a near-infrared (NIR) camera and an NIR light-emitting diode. Twenty-four subjects watched two-dimensional (2D) and three-dimensional (3D) stereoscopic videos of the same content, and the changes in pupil size were measured by using the eye-capturing device and image-processing methods: RESULTS. The pupil size changed with the intensity of the videos and the disparities between the left and right images of a 3D stereoscopic video. There was correlation between the pupil size and average intensity. The pupil diameter could be estimated as being contracted from approximately 5.96 to 4.25 mm as the intensity varied from 0 to 255. Further, from the changes in the depth fixation for the pupil accommodation, it was confirmed that the depth fixation also affected accommodation of pupil size. CONCLUSIONS. It was confirmed that the lighting condition was an even more significant factor in pupil accommodation than was depth fixation (significance ratio: approximately 3.2:1) when watching 3D stereoscopic video. Pupil accommodation was more affected by depth fixation in the real world than was the binocular convergence in the 3D stereoscopic display.

Mapping and correcting the influence of gaze position on pupil size measurements

PubMed Central

Petrov, Alexander A.

2015-01-01

Pupil size is correlated with a wide variety of important cognitive variables and is increasingly being used by cognitive scientists. Pupil data can be recorded inexpensively and non-invasively by many commonly used video-based eye-tracking cameras. Despite the relative ease of data collection and increasing prevalence of pupil data in the cognitive literature, researchers often underestimate the methodological challenges associated with controlling for confounds that can result in misinterpretation of their data. One serious confound that is often not properly controlled is pupil foreshortening error (PFE)—the foreshortening of the pupil image as the eye rotates away from the camera. Here we systematically map PFE using an artificial eye model and then apply a geometric model correction. Three artificial eyes with different fixed pupil sizes were used to systematically measure changes in pupil size as a function of gaze position with a desktop EyeLink 1000 tracker. A grid-based map of pupil measurements was recorded with each artificial eye across three experimental layouts of the eye-tracking camera and display. Large, systematic deviations in pupil size were observed across all nine maps. The measured PFE was corrected by a geometric model that expressed the foreshortening of the pupil area as a function of the cosine of the angle between the eye-to-camera axis and the eye-to-stimulus axis. The model reduced the root mean squared error of pupil measurements by 82.5 % when the model parameters were pre-set to the physical layout dimensions, and by 97.5 % when they were optimized to fit the empirical error surface. PMID:25953668

Pupil size tracks perceptual content and surprise.

PubMed

Kloosterman, Niels A; Meindertsma, Thomas; van Loon, Anouk M; Lamme, Victor A F; Bonneh, Yoram S; Donner, Tobias H

2015-04-01

Changes in pupil size at constant light levels reflect the activity of neuromodulatory brainstem centers that control global brain state. These endogenously driven pupil dynamics can be synchronized with cognitive acts. For example, the pupil dilates during the spontaneous switches of perception of a constant sensory input in bistable perceptual illusions. It is unknown whether this pupil dilation only indicates the occurrence of perceptual switches, or also their content. Here, we measured pupil diameter in human subjects reporting the subjective disappearance and re-appearance of a physically constant visual target surrounded by a moving pattern ('motion-induced blindness' illusion). We show that the pupil dilates during the perceptual switches in the illusion and a stimulus-evoked 'replay' of that illusion. Critically, the switch-related pupil dilation encodes perceptual content, with larger amplitude for disappearance than re-appearance. This difference in pupil response amplitude enables prediction of the type of report (disappearance vs. re-appearance) on individual switches (receiver-operating characteristic: 61%). The amplitude difference is independent of the relative durations of target-visible and target-invisible intervals and subjects' overt behavioral report of the perceptual switches. Further, we show that pupil dilation during the replay also scales with the level of surprise about the timing of switches, but there is no evidence for an interaction between the effects of surprise and perceptual content on the pupil response. Taken together, our results suggest that pupil-linked brain systems track both the content of, and surprise about, perceptual events. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

The Potential Role of Schools and Teachers in the Character Development of Young People in England: Perspectives from Pupils and Teachers

ERIC Educational Resources Information Center

See, Beng Huat; Arthur, James

2011-01-01

This paper considers the potential role of schools and teachers in the character development of pupils aged 10-19. It is based largely on the views of 5207 pupils in England, drawn from 25 state schools, including five primaries. Data include document contents, interviews and surveys with pupils and their teachers. Pupil accounts suggest that…

Wave-Optics Analysis of Pupil Imaging

NASA Technical Reports Server (NTRS)

Dean, Bruce H.; Bos, Brent J.

2006-01-01

Pupil imaging performance is analyzed from the perspective of physical optics. A multi-plane diffraction model is constructed by propagating the scalar electromagnetic field, surface by surface, along the optical path comprising the pupil imaging optical system. Modeling results are compared with pupil images collected in the laboratory. The experimental setup, although generic for pupil imaging systems in general, has application to the James Webb Space Telescope (JWST) optical system characterization where the pupil images are used as a constraint to the wavefront sensing and control process. Practical design considerations follow from the diffraction modeling which are discussed in the context of the JWST Observatory.

Is Tadpole Pupil in an Adolescent Girl Caused by Denervation Hypersensitivity?

PubMed

Hansen, Jonas Kjeldbjerg; Møller, Hans Ulrik

2017-06-01

Tadpole pupil is a rarely encountered phenomenon caused by episodic, segmental iris dilator muscle spasm of short duration (2-15 minutes), occurring in clusters without a known precipitating factor. It has most commonly been described in women aged 28 to 48 years. A few hypotheses on pathogenesis have been discussed but none has been proved. Here, we present an adolescent girl with bilateral tadpole pupil that appeared during physical exercise. This is the first pediatric case of tadpole pupil, not caused by preceding surgery, to be published. Based on (1) this case in which tadpole pupil developed when the norepinephrine level rose during exercise, (2) the high ratio of patients with tadpole pupil who concurrently have or later develop Horner syndrome, in which denervation hypersensitivity is well described, (3) a previous report of a patient with both tadpole pupil and Horner syndrome who had denervation hypersensitivity on pharmacological testing, (4) a 29-year-old man with unilateral tadpole pupil induced by exercise, and (5) a 19-year-old man with bilateral tadpole pupil and possible autonomic neuropathy, we suggest denervation hypersensitivity as a probable pathogenic mechanism causing tadpole pupil. In addition, a suggestion for investigations to be performed in future pediatric cases is provided. Georg Thieme Verlag KG Stuttgart · New York.

Phase shifting interferometer

DOEpatents

Sommargren, Gary E.

1999-01-01

An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. Whereas current interferometers illuminate the optic to be tested with an aberrated wavefront which also limits the accuracy of the measurement, this interferometer uses an essentially perfect spherical measurement wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.

Phase shifting interferometer

DOEpatents

Sommargren, G.E.

1999-08-03

An interferometer is disclosed which has the capability of measuring optical elements and systems with an accuracy of {lambda}/1000 where {lambda} is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about {lambda}/50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. Whereas current interferometers illuminate the optic to be tested with an aberrated wavefront which also limits the accuracy of the measurement, this interferometer uses an essentially perfect spherical measurement wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms. 11 figs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shyu, Lih-Horng; Chang, Chung-Ping; Wang, Yung-Cheng

Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, themore » intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.« less

Sensitivity of a fibre scattered-light interferometer to external phase perturbations in an optical fibre

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alekseev, A E; Potapov, V T; Gorshkov, B G

2015-10-31

Sensitivity of a fibre scattered-light interferometer to external phase perturbations is studied for the first time. An expression is derived for an average power of a useful signal at the interferometer output under external harmonic perturbations in a signal fibre of the interferometer. It is shown that the maximum sensitivity of the scattered-light interferometer depends on the dispersion of the interferogram intensity. An average signal-to-noise ratio is determined theoretically and experimentally at the output of the interferometer at different amplitudes of external perturbations. Using the measured dependences of the signal-to-noise ratio, the threshold sensitivity of the fibre scattered-light interferometer tomore » external phase perturbations is found. The results obtained can be used to optimise characteristics of optical time-domain reflectometers and to design individual phase-sensitive fibre-optic sensors. (laser applications and other topics in quantum electronics)« less

Remapping Genre: Spanish Jaiku of the Early Twentieth Century

ERIC Educational Resources Information Center

Landeira, Joy

2010-01-01

At the beginning of the twentieth century a new subgenre of poetry written in Spanish, but rooted in Japanese literary tradition, began to emerge in the works of Spain's vanguard and Generation of 1927 poets and among young modernist poets in Mexico and South America. Transmitted first through France and later directly from Japan, the popularity…

Improving Students' Critical Thinking Skills through Remap NHT in Biology Classroom

ERIC Educational Resources Information Center

Mahanal, Susriyati; Zubaidah, Siti; Bahri, Arsad; Syahadatud Dinnurriya, Maratusy

2016-01-01

Previous studies in Malang, Indonesia, showed that there were the failure biology learning caused by not only the low students' prior knowledge, but also biology learning model has not improved the students' critical thinking skills yet, which affected the low of cognitive learning outcomes. The learning model is required to improve students'…

Remapping Englishness--the Impact of Globalization on College English Instruction in Taiwan

ERIC Educational Resources Information Center

Lee, Jade Tsui-yu

2008-01-01

The purpose of this paper is to examine the impact of globalization upon the college-level instruction of English/American literature in Taiwan. The examination will be centered upon the subject of Englishness as demonstrated in the courses of English/American Literature taught in Taiwan. By focusing on the term "Englishness," the paper…

A Michelson-type radio interferometer for university education

NASA Astrophysics Data System (ADS)

Koda, Jin; Barrett, James; Shafto, Gene; Slechta, Jeff; Hasegawa, Tetsuo; Hayashi, Masahiko; Metchev, Stanimir

2016-04-01

We report development of a simple and affordable radio interferometer suitable as an educational laboratory experiment. The design of this interferometer is based on the Michelson and Pease stellar optical interferometer, but instead operates at the radio wavelength of ˜11 GHz (˜2.7 cm), requiring much less stringent optical accuracy in its design and use. We utilize a commercial broadcast satellite dish and feedhorn with two flat side mirrors that slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, even on a day with marginal weather. Commercial broadcast satellites provide convenient point sources for comparison to the Sun's extended disk. The mathematical background of an adding interferometer is presented, as is its design and development, including the receiver system, and sample measurements of the Sun. Results from a student laboratory report are shown. With the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the future generation of astronomers. This interferometer provides the hands-on experience needed to fully understand the basic concepts of interferometry.

Michelson-type Radio Interferometer for University Education

NASA Astrophysics Data System (ADS)

Koda, Jin; Barrett, J. W.; Hasegawa, T.; Hayashi, M.; Shafto, G.; Slechta, J.

2013-01-01

Despite the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the futue generation of astronomers. Students need hands-on experiments to fully understand the basic concepts of interferometry. Professional interferometers are often too complicated for education, and it is difficult to guarantee access for classes in a university course. We have built a simple and affordable radio interferometer for education and used it for an undergraduate and graduate laboratory project. This interferometer's design is based on the Michelson & Peace's stellar optical interferometer, but operates at a radio wavelength using a commercial broadcast satellite dish and receiver. Two side mirrors are surfaced with kitchen aluminum foil and slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, a nice daytime experiment which can be carried out even under a marginal weather (i.e., partial cloud coverage). Commercial broadcast satellites provide convenient point sources. By comparing the Sun and satellites, students can learn how an interferometer works and resolves structures in the sky.

Three-dimensional relationship between high-order root-mean-square wavefront error, pupil diameter, and aging

PubMed Central

Applegate, Raymond A.; Donnelly, William J.; Marsack, Jason D.; Koenig, Darren E.; Pesudovs, Konrad

2007-01-01

We report root-mean-square (RMS) wavefront error (WFE) for individual aberrations and cumulative high-order (HO) RMS WFE for the normal human eye as a function of age by decade and pupil diameter in 1 mm steps from 3 to 7 mm and determine the relationship among HO RMS WFE, mean age for each decade of life, and luminance for physiologic pupil diameters. Subjects included 146 healthy individuals from 20 to 80 years of age. Ocular aberration was measured on the preferred eye of each subject (for a total of 146 eyes through dilated pupils; computed for 3, 4, 5, 6, and 7 mm pupils; and described with a tenth-radial-order normalized Zernike expansion. We found that HO RMS WFE increases faster with increasing pupil diameter for any given age and pupil diameter than it does with increasing age alone. A planar function accounts for 99% of the variance in the 3-D space defined by mean log HO RMS WFE, mean age for each decade of life, and pupil diameter. When physiologic pupil diameters are used to estimate HO RMS WFE as a function of luminance and age, at low luminance (9 cd/m2) HO RMS WFE decreases with increasing age. This normative data set details (1) the 3-D relationship between HO RMS WFE and age for fixed pupil diameters and (2) the 3-D relationship among HO RMS WFE, age, and luminance for physiologic pupil diameters. PMID:17301847

Fizeau simultaneous phase-shifting interferometry based on extended source

NASA Astrophysics Data System (ADS)

Wang, Shanshan; Zhu, Qiudong; Hou, Yinlong; Cao, Zheng

2016-09-01

Coaxial Fizeau simultaneous phase-shifting interferometer plays an important role in many fields for its characteristics of long optical path, miniaturization, and elimination of reference surface high-frequency error. Based on the matching of coherence between extended source and interferometer, orthogonal polarization reference wave and measurement wave can be obtained by Fizeau interferometry with Michelson interferometer preposed. Through matching spatial coherence length between preposed interferometer and primary interferometer, high contrast interference fringes can be obtained and additional interference fringes can be eliminated. Thus, the problem of separation of measurement and reference surface in the common optical path Fizeau interferometer is solved. Numerical simulation and principle experiment is conducted to verify the feasibility of extended source interferometer. Simulation platform is established by using the communication technique of DDE (dynamic data exchange) to connect Zemax and Matlab. The modeling of the extended source interferometer is realized by using Zemax. Matlab codes are programmed to automatically rectify the field parameters of the optical system and conveniently calculate the visibility of interference fringes. Combined with the simulation, the experimental platform of the extended source interferometer is established. After experimental research on the influence law of scattering screen granularity to interference fringes, the granularity of scattering screen is determined. Based on the simulation platform and experimental platform, the impacts on phase measurement accuracy of the imaging system aberration and collimation system aberration of the interferometer are analyzed. Compared the visibility relation curves between experimental measurement and simulation result, the experimental result is in line with the theoretical result.

Wavefront Curvature Sensing from Image Projections

DTIC Science & Technology

2006-09-01

entrance pupil. The generalized pupil function, denoted P, provides a basic 1-7 mathematical model for the optical �eld at the system pupil: P(x; y...pupil or aperture radius, RP , may be included in Zernike functions and windowing functions to give the notation more generality . Given some ...promises a much faster read out time from the CCD along with some amount of information useful for estimating pupil phase. A General Image Projection

Clear-cornea cataract surgery: pupil size and shape changes, along with anterior chamber volume and depth changes. A Scheimpflug imaging study.

PubMed

Kanellopoulos, Anastasios John; Asimellis, George

2014-01-01

To investigate, by high-precision digital analysis of data provided by Scheimpflug imaging, changes in pupil size and shape and anterior chamber (AC) parameters following cataract surgery. The study group (86 eyes, patient age 70.58±10.33 years) was subjected to cataract removal surgery with in-the-bag intraocular lens implantation (pseudophakic). A control group of 75 healthy eyes (patient age 51.14±16.27 years) was employed for comparison. Scheimpflug imaging (preoperatively and 3 months postoperatively) was employed to investigate central corneal thickness, AC depth, and AC volume. In addition, by digitally analyzing the black-and-white dotted line pupil edge marking in the Scheimpflug "large maps," the horizontal and vertical pupil diameters were individually measured and the pupil eccentricity was calculated. The correlations between AC depth and pupil shape parameters versus patient age, as well as the postoperative AC and pupil size and shape changes, were investigated. Compared to preoperative measurements, AC depth and AC volume of the pseudophakic eyes increased by 0.99±0.46 mm (39%; P<0.001) and 43.57±24.59 mm(3) (36%; P<0.001), respectively. Pupil size analysis showed that the horizontal pupil diameter was reduced by -0.27±0.22 mm (-9.7%; P=0.001) and the vertical pupil diameter was reduced by -0.32±0.24 mm (-11%; P<0.001). Pupil eccentricity was reduced by -39.56%; P<0.001. Cataract extraction surgery appears to affect pupil size and shape, possibly in correlation to AC depth increase. This novel investigation based on digital analysis of Scheimpflug imaging data suggests that the cataract postoperative photopic pupil is reduced and more circular. These changes appear to be more significant with increasing patient age.

Assessing Visual Delays using Pupil Oscillations

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.

2012-01-01

Stark (1962) demonstrated vigorous pupil oscillations by illuminating the retina with a beam of light focussed to a small spot near the edge of the pupil. Small constrictions of the pupil then are sufficient to completely block the beam, amplifying the normal relationship between pupil area and retinal illuminance. In addition to this simple and elegant method, Stark also investigated more complex feedback systems using an electronic "clamping box" which provided arbitrary gain and phase delay between a measurement of pupil area and an electronically controlled light source. We have replicated Stark's results using a video-based pupillometer to control the luminance of a display monitor. Pupil oscillations were induced by imposing a linear relationship between pupil area and display luminance, with a variable delay. Slopes of the period-vs-delay function for 3 subjects are close to the predicted value of 2 (1.96-2.39), and the implied delays range from 254 to 376 508 to 652 milliseconds. Our setup allows us to extend Stark's work by investigating a broader class of stimuli.

[Correspondence analysis of association between types of unintentional injuries and influential factors among rural rear pupils].

PubMed

Dou, Dongmei; Wang, Peixi

2015-07-01

To explore the association between types of unintentional injuries and influential factors among rural rear pupils. The multistage stratified sampling method was used to select the study participant and thus 594 rural pupils were sampled, 292 rear pupils were confirmed and measured with unintentional injuries and influential factors of rural rear pupils scale. Binary logistic regression analysis indicate that the risk facts related to unintentional injury were left-behind status (OR = 2.68, 95% CI 1.06-6.79), gender (OR = 5.12, 95% C2.68-9.79) and surrounding environment (OR = 3.44, 95% CI 1.37-8.70). Correspondence analysis showed living with father, middle personality and low age were related possibly with traffic accident injury. Living with grandparents, extrovert personality and elder pupils were related possibly with unintentional falls injury. Living with mother, introvert personality and middle-age pupils were related possibly with animmal injury. The personality, ages and guardian types of rural rear pupils are correlated with types of unintentional injuries.

National campaign effects on secondary pupils' bullying and violence.

PubMed

Mooij, Ton

2005-09-01

Research on pupils' bullying (1991) and violence (1993) motivated the Dutch Ministry of Education, Culture and Science to initiate a national campaign on school safety. The government campaign was undertaken from 1995 to 2000. To test for differences in secondary pupils' bullying and violence before and after the campaign while controlling for different contextual variables. In 1991, a representative survey on bullying was conducted in 36 secondary schools with 1,055 pupils from Year 2 and 4 classes (age range 13-16 years). In 1993, a survey on violent behaviour took place in 71 secondary schools with 1,998 pupils from Year 3 and 4 classes (age range 14-16 years). In 2000, a survey on bullying and violence was conducted in 60 secondary schools with 9,948 pupils from Year 1 to 6 classes (age range 12-18 years). The data from pupils in identical school years were compared with respect to bullying (1991-2000) and violence (1993-2000). The statistical relations were analysed in two stepwise multiple regression analyses. Year of investigation (1991- 2000, 1993-2000) was the respective dependent variable. The independent variables were pupils' bullying or violence scores, sex, school year, contextual lesson, school, and community variables. In both regression analyses, the contextual lesson and school variables discriminated between the measurement years. Also, compared with 1991, the pupils in 2000 scored lower for being a bully and higher for being bullied directly. Compared with 1993, the pupils in 2000 scored lower for being a victim of intentional damage to property or emotional violence, lower for being a perpetrator of disruptive behaviour in school, and higher for being a perpetrator of intentional damage to property. The differences between the contextual variables measured before and after the campaign reflect changes in educational and instructional situations. Independent of these differences, the national campaign appears to have helped improve the awareness of pupils' social behaviour and elicit, in particular, a decrease in pupils' violent behaviour. However, more specific pedagogical and preventative support for pupils socially at risk appears to be needed to have a more prosocial impact on the behaviour of secondary school pupils.

Broad source fringe formation with a Fresnel biprism and a Mach-Zehnder interferometer.

PubMed

Leon, S C

1987-12-15

A biprism is used to combine identical spatially incoherent wavefronts that have been split by an amplitude splitting interferometer such as the Mach-Zehnder. The performance of this composite interferometer is evaluated by tracing the chief ray through parallel optical systems using Snell's law and trigonometry. Fringes formed in spatially incoherent light with this optical system are compared with those formed using the Mach-Zehnder and grating interferometers. It is shown that the combination can exhibit extended source fringe formation capability greatly exceeding that of the Mach-Zehnder interferometer.

Chemical micro-sensor

DOEpatents

Ruggiero, Anthony J.

2005-05-03

An integrated optical capillary electrophoresis system for analyzing an analyte. A modulated optical pump beam impinges on an capillary containing the analyte/buffer solution which is separated by electrophoresis. The thermally-induced change in the index of refraction of light in said electrophoresis capillary is monitored using an integrated micro-interferometer. The interferometer includes a first interferometer arm intersecting the electrophoresis capillary proximate the excitation beam and a second, reference interferometer arm. Changes in index of refraction in the analyte measured by interrogating the interferometer state using white light interferometry and a phase-generated carrier demodulation technique. Background thermo-optical activity in the buffer solution is cancelled by splitting the pump beam and exciting pure buffer solution in a second section of capillary where it crosses the reference arm of the interferometer.

Chimpanzees and Humans Mimic Pupil-Size of Conspecifics

PubMed Central

Kret, Mariska E.; Tomonaga, Masaki; Matsuzawa, Tetsuro

2014-01-01

Group-living typically provides benefits to individual group members but also confers costs. To avoid incredulity and betrayal and allow trust and cooperation, individuals must understand the intentions and emotions of their group members. Humans attend to other's eyes and from gaze and pupil-size cues, infer information about the state of mind of the observed. In humans, pupil-size tends to mimic that of the observed. Here we tested whether pupil-mimicry exists in our closest relative, the chimpanzee (P. troglodytes). We conjectured that if pupil-mimicry has adaptive value, e.g. to promote swift communication of inner states and facilitate shared understanding and coordination, pupil-mimicry should emerge within but not across species. Pupillometry data was collected from human and chimpanzee subjects while they observed images of the eyes of both species with dilating/constricting pupils. Both species showed enhanced pupil-mimicry with members of their own species, with effects being strongest in humans and chimpanzee mothers. Pupil-mimicry may be deeply-rooted, but probably gained importance from the point in human evolution where the morphology of our eyes became more prominent. Humans' white sclera surrounding the iris, and the fine muscles around their eyes facilitate non-verbal communication via eye signals. PMID:25140998

Zernike expansion coefficients: rescaling and decentring for different pupils and evaluation of corneal aberrations

NASA Astrophysics Data System (ADS)

Comastri, Silvia A.; Perez, Liliana I.; Pérez, Gervasio D.; Martin, Gabriel; Bastida, Karina

2007-03-01

An analytical method to convert the set of Zernike coefficients that fits the wavefront aberration for a pupil into another corresponding to a contracted and horizontally translated pupil is proposed. The underlying selection rules are provided and the resulting conversion formulae for a seventh-order expansion are given. These formulae are applied to calculate corneal aberrations referred to a given pupil centre in terms of those referred to the keratometric vertex supplied by the SN CT1000 topographer. Four typical cases are considered: a sphere and three eyes—normal, keratoconic and post-LASIK. When the pupil centre is fixed and the pupil diameter decreases from 6 mm to the photopic natural one, leaving aside piston, tilt and defocus, the difference between the root mean square wavefront error computed with the formulae and the topographer is less than 0.04 µm. When the pupil diameter is kept equal to the natural one and the pupil centre is displaced, coefficients vary according to the eye. For a 0.3 mm pupil shift, the variation of coma is at most 0.35 µm and that of spherical aberration 0.01 µm.

Accommodation and pupil responses to random-dot stereograms

PubMed Central

Suryakumar, Rajaraman; Allison, Robert

2015-01-01

We investigated the dynamics of accommodative and pupillary responses to random-dot stereograms presented in crossed and uncrossed disparity in six visually normal young adult subjects (mean age = 25.8 ± 3.1 years). Accommodation and pupil measures were monitored monocularly with a custom built photorefraction system while subjects fixated at the center of a random-dot stereogram. On each trial, the stereogram initially depicted a flat plane and then changed to depict a sinusoidal corrugation in depth while fixation remained constant. Increase in disparity specified depth resulted in pupil constriction during both crossed and uncrossed disparity presentations. The change in pupil size between crossed and uncrossed disparity conditions was not significantly different (p > 0.05). The change in pupil size was also accompanied by a small concomitant increase in accommodation. In addition, the dynamic properties of pupil responses varied as a function of their initial (starting) diameter. The finding that accommodation and pupil responses increased with disparity regardless of the sign of retinal disparity suggests that these responses were driven by apparent depth rather than shifts in mean simulated distance of the stimulus. Presumably the need for the increased depth of focus when viewing stimuli extended in depth results in pupil constriction which also results in a concomitant change in accommodation. Starting position effects in pupil response confirm the non-linearity in the operating range of the pupil. PMID:25891121

Pupil shape in the animal kingdom: from the pseudopupil to the vertical pupil.

PubMed

González-Martín-Moro, J; Gómez-Sanz, F; Sales-Sanz, A; Huguet-Baudin, E; Murube-del-Castillo, J

2014-12-01

To study the different pupil shapes adopted by the different animal species. Review of the related literature, using PubMed database. The initial search strategy was pupil shape (limited to animals). The first volume of System of Ophthalmology (Duke-Elder) and Evolution's witness (I. Schwab) were also reviewed. An optic illusion called pseudopupil is usually observed in the compound eyes of insects. The pupil is circular in most vertebrates, however slit vertical pupils are present in cats and in some snake species. Vertical pupils could have a photoprotective function, as it makes a more complete closure possible in photopic conditions, and helps to camouflage the predator. It has also been hypothesized that it could help to correct chromatic aberration. Ruminants are usually endowed with horizontal pupils. This shape could improve the capacity of the eye to detect vertical silhouettes. Some marine animals have crescent-shaped pupils. In these animals, a superior operculum helps to protect the inferior retina from the great amount of light coming from above. There is a surprising variability in pupil shape. Through this variability, nature has fitted the eye to different circumstances. The theories proposed to explain this high variability are discussed in detail in the article. Copyright © 2012 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.

Orthonormal aberration polynomials for anamorphic optical imaging systems with rectangular pupils.

PubMed

Mahajan, Virendra N

2010-12-20

The classical aberrations of an anamorphic optical imaging system, representing the terms of a power-series expansion of its aberration function, are separable in the Cartesian coordinates of a point on its pupil. We discuss the balancing of a classical aberration of a certain order with one or more such aberrations of lower order to minimize its variance across a rectangular pupil of such a system. We show that the balanced aberrations are the products of two Legendre polynomials, one for each of the two Cartesian coordinates of the pupil point. The compound Legendre polynomials are orthogonal across a rectangular pupil and, like the classical aberrations, are inherently separable in the Cartesian coordinates of the pupil point. They are different from the balanced aberrations and the corresponding orthogonal polynomials for a system with rotational symmetry but a rectangular pupil.

Measurement of EUV lithography pupil amplitude and phase variation via image-based methodology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levinson, Zachary; Verduijn, Erik; Wood, Obert R.

2016-04-01

Here, an approach to image-based EUV aberration metrology using binary mask targets and iterative model-based solutions to extract both the amplitude and phase components of the aberrated pupil function is presented. The approach is enabled through previously developed modeling, fitting, and extraction algorithms. We seek to examine the behavior of pupil amplitude variation in real-optical systems. Optimized target images were captured under several conditions to fit the resulting pupil responses. Both the amplitude and phase components of the pupil function were extracted from a zone-plate-based EUV mask microscope. The pupil amplitude variation was expanded in three different bases: Zernike polynomials,more » Legendre polynomials, and Hermite polynomials. It was found that the Zernike polynomials describe pupil amplitude variation most effectively of the three.« less

Pupillary response to direct and consensual chromatic light stimuli.

PubMed

Traustason, Sindri; Brondsted, Adam Elias; Sander, Birgit; Lund-Andersen, Henrik

2016-02-01

To assess whether the direct and consensual postillumination (ipRGC-driven) pupil light responses to chromatic light stimuli are equal in healthy subjects. Pupil responses in healthy volunteers were recorded using a prototype binocular chromatic pupillometer (IdeaMedical, Copenhagen), which is capable of both direct and consensual pupillometry measurements. The device uses a pair of dual monochromatic narrow bandwidth LED light sources, red (660 nm) and blue (470 nm). Pupil light responses were recorded with infrared video cameras and analysed using custom-made circuitry and software. Subjects were randomized to receive light stimuli at either the right or left eye after 5 min of dark adaptation. Pupil light responses were recorded in both eyes for 10 seconds before illumination, during illumination and 50 seconds after illumination with red and blue light. Three variables were defined for the recorded pupil responses: the maximal constriction amplitude (CAmax ), the pupil response during illumination and postillumination pupil response (PIPR). No difference was found in the pupil response to blue light. With red light, the pupil response during illumination was slightly larger during consensual illumination compared to direct illumination (0.54 and 0.52, respectively, p = 0.027, paired Wilcoxon's test, n = 12), while no differences were found for CAmax or the PIPR. No difference was found between direct and consensual pupil response to either red or blue light in the postillumination period. Direct and consensual responses can readily be compared when examining the postillumination pupil response to blue light as estimation of photosensitive retinal ganglion cell activation. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

On Pupils' Self-Confidence in Mathematics: Gender Comparisons

ERIC Educational Resources Information Center

Nurmi, Anu; Hannula, Markku; Maijala, Hanna; Pehkonen, Erkki

2003-01-01

In this paper we will concentrate on pupils' self-confidence in mathematics, which belongs to pupils' mathematical beliefs in themselves, and beliefs on achievement in mathematics. Research described consists of a survey of more than 3000 fifth-graders and seventh-graders. Furthermore, 40 pupils participated in a qualitative follow-up study…

Pupils' Perspectives on the Lived Pedagogy of the Classroom

ERIC Educational Resources Information Center

Niemi, Reetta; Kumpulainen, Kristiina; Lipponen, Lasse; Hilppö, Jaakko

2015-01-01

This paper is based on a pedagogical action research initiative that explores what constitutes the "lived pedagogy" of the classroom from the pupils' perspective. Photography and group interviews were utilised to allow pupils to express their perspectives. The results show that pupils considered situations meaningful when they were able…

The Conceptual Design of the Magdalena Ridge Observatory Interferometer

NASA Astrophysics Data System (ADS)

Buscher, D. F.; Creech-Eakman, M.; Farris, A.; Haniff, C. A.; Young, J. S.

We describe the scientific motivation for and conceptual design of the Magdalena Ridge Observatory Interferometer, an imaging interferometer designed to operate at visible and near-infrared wavelengths. The rationale for the major technical decisions in the interferometer design is discussed, the success of the concept is appraised, and the implications of this analysis for the design of future arrays are drawn out.

Interferometer for the measurement of plasma density

DOEpatents

Jacobson, Abram R.

1980-01-01

An interferometer which combines the advantages of a coupled cavity interferometer requiring alignment of only one light beam, and a quadrature interferometer which has the ability to track multi-fringe phase excursions unambiguously. The device utilizes a Bragg cell for generating a signal which is electronically analyzed to unambiguously determine phase modulation which is proportional to the path integral of the plasma density.

The Mount Wilson optical interferometer: The first automated instrument and the prospects for lunar interferometry

NASA Technical Reports Server (NTRS)

Johnston, Ken J.; Mozurkewich, D.; Simon, R. S.; Shao, Michael; Colavita, M.

1992-01-01

Before contemplating an optical interferometer on the Moon one must first review the accomplishments achieved by this technology in scientific applications for astronomy. This will be done by presenting the technical status of optical interferometry as achieved by the Mount Wilson Optical Interferometer. The further developments needed for a future lunar-based interferometer are discussed.

Analysis for signal-to-noise ratio of hyper-spectral imaging FTIR interferometer

NASA Astrophysics Data System (ADS)

Li, Xun-niu; Zheng, Wei-jian; Lei, Zheng-gang; Wang, Hai-yang; Fu, Yan-peng

2013-08-01

Signal-to-noise Ratio of hyper-spectral imaging FTIR interferometer system plays a decisive role on the performance of the instrument. It is necessary to analyze them in the development process. Based on the simplified target/background model, the energy transfer model of the LWIR hyper-spectral imaging interferometer has been discussed. The noise equivalent spectral radiance (NESR) and its influencing factors of the interferometer system was analyzed, and the signal-to-noise（SNR） was calculated by using the properties of NESR and incident radiance. In a typical application environment, using standard atmospheric model of USA(1976 COESA) as a background, and set a reasonable target/background temperature difference, and take Michelson spatial modulation Fourier Transform interferometer as an example, the paper had calculated the NESR and the SNR of the interferometer system which using the commercially LWIR cooled FPA and UFPA detector. The system noise sources of the instrument were also analyzed in the paper. The results of those analyses can be used to optimize and pre-estimate the performance of the interferometer system, and analysis the applicable conditions of use different detectors. It has important guiding significance for the LWIR interferometer spectrometer design.

Phase conjugate Twyman-Green interferometer for testing spherical surfaces and lenses and for measuring refractive indices of liquids or solid transparent materials

NASA Technical Reports Server (NTRS)

Shukla, R. P.; Dokhanian, Mostafa; Venkateswarlu, Putcha; George, M. C.

1990-01-01

The present paper describes an application of a phase conjugate Twyman-Green interferometer using barium titanate as a self-pumping mirror for testing optical components like concave and convex spherical mirrors and lenses. The aberrations introduced by the beam splitter while testing concave or convex spherical mirrors of large aperture are automatically eliminated due to self-focussing property of the phase conjugate mirror. There is no necessity for a good spherical surface as a reference surface unlike in classical Twyman-Green interferometer or Williams interferometer. The phase conjugate Twyman Green interferometer with a divergent illumination can be used as a test plate for checking spherical surfaces. A nondestructive technique for measuring the refractive indices of a Fabry Perot etalon by using a phase conjugate interferometer is also suggested. The interferometer is found to be useful for measuring the refractive indices of liquids and solid transparent materials with an accuracy of the order of + or - 0.0004.

Optical fiber voltage sensor based on Michelsion interferometer using Fabry-Perot demodulation interferometer

NASA Astrophysics Data System (ADS)

Chen, Xinwei; He, Shengnan; Li, Dandan; Wang, Kai; Fan, Yan'en; Wu, Shuai

2014-11-01

We present an optical fiber voltage sensor by Michelsion interferometer (MI) employing a Fabry-Perot (F-P) interferometer and the DC phase tracking (DCPT) signal processing method. By mounting a MI fabricated by an optical fiber coupler on a piezoelectric (PZT) transducer bar, a dynamic strain would be generated to change the optical path difference (OPD) of the interferometer when the measured voltage was applied on the PZT. Applying an F-P interferometer to demodulate the optical intensity variation output of the MI, the voltage can be obtained. The experiment results show that the relationship between the optical intensity variation and the voltage applied on the PZT is approximately linear. Furthermore, the phase generate carrier (PGC) algorithm was applied to demodulate the output of the sensor also.

Pupil geometry and pupil re-imaging in telescope arrays

NASA Technical Reports Server (NTRS)

Traub, Wesley A.

1990-01-01

This paper considers the issues of lateral and longitudinal pupil geometry in ground-based telescope arrays, such as IOTA. In particular, it is considered whether or not pupil re-imaging is required before beam combination. By considering the paths of rays through the system, an expression is derived for the optical path errors in the combined wavefront as a function of array dimensions, telescope magnification factor, viewing angle, and field-of-view. By examining this expression for the two cases of pupil-plane and image-plane combination, operational limits can be found for any array. As a particular example, it is shown that for IOTA no pupil re-imaging optics will be needed.

Precise calibration of pupil images in pyramid wavefront sensor.

PubMed

Liu, Yong; Mu, Quanquan; Cao, Zhaoliang; Hu, Lifa; Yang, Chengliang; Xuan, Li

2017-04-20

The pyramid wavefront sensor (PWFS) is a novel wavefront sensor with several inspiring advantages compared with Shack-Hartmann wavefront sensors. The PWFS uses four pupil images to calculate the local tilt of the incoming wavefront. Pupil images are conjugated with a telescope pupil so that each pixel in the pupil image is diffraction-limited by the telescope pupil diameter, thus the sensing error of the PWFS is much lower than that of the Shack-Hartmann sensor and is related to the extraction and alignment accuracy of pupil images. However, precise extraction of these images is difficult to conduct in practice. Aiming at improving the sensing accuracy, we analyzed the physical model of calibration of a PWFS and put forward an extraction algorithm. The process was verified via a closed-loop correction experiment. The results showed that the sensing accuracy of the PWFS increased after applying the calibration and extraction method.

Results of single burr hole drainage for acute subdural hematoma with non-reactive pupil.

PubMed

Yanagawa, Youichi; Sakamoto, Toshihisa

2012-01-01

To investigate the effects of emergency burr hole drainage for acute subdural hematoma (ASDH) with bilateral non-reactive pupils. A retrospective study was conducted by reviewing medical records from 1998 to 2007. Patients meeting the following criteria were included: 1) head injury with unconsciousness (Glasgow Coma Scale score 8); 2) bilateral non-reactive pupils on arrival; 3) ASDH with disappearance of basal cistern on computed tomography (CT); and 4) performance of emergency single burr hole drainage. Subjects were divided into survival and non-survival groups. Pupil size on the small side was significantly smaller in the survival group than in the non-survival group. All pupils on the small side in the survival group were 4 mm. Emergency burr hole drainage should still be considered in patients with ASDH showing bilateral non-reactive pupils and one pupil 4 mm.

Judging a book by its cover: the unconscious influence of pupil size on consumer choice.

PubMed

Wiseman, Richard; Watt, Caroline

2010-01-01

Past research suggests that men perceive women with large pupils as especially attractive. We employed an innovative methodology to examine whether this effect influences consumer decision-making. A popular psychology book was published with two slightly different front covers. Both covers contained the same photograph of a woman; however, the woman's pupils on one cover were digitally enlarged. Readers indicated whether they were male or female, and whether they possessed the cover with small or large pupils. A significantly greater percentage of men than women had chosen the cover with the large pupils. None of the participants who attempted to guess the nature of the experiment was correct, suggesting that the influence exerted by pupil size was unconscious. These findings provide further support for the notion that people's judgments are unconsciously swayed by pupil size, and demonstrate that this effect operates in a real world setting.

The impact of a multiple intelligences teaching approach drug education programme on drug refusal skills of Nigerian pupils.

PubMed

Nwagu, Evelyn N; Ezedum, Chuks E; Nwagu, Eric K N

2015-09-01

The rising incidence of drug abuse among youths in Nigeria is a source of concern for health educators. This study was carried out on primary six pupils to determine the effect of a Multiple Intelligences Teaching Approach Drug Education Programme (MITA-DEP) on pupils' acquisition of drug refusal skills. A programme of drug education based on the Multiple Intelligences Teaching Approach (MITA) was developed. An experimental group was taught using this programme while a control group was taught using the same programme but developed based on the Traditional Teaching Approach. Pupils taught with the MITA acquired more drug refusal skills than those taught with the Traditional Teaching Approach. Urban pupils taught with the MITA acquired more skills than rural pupils. There was no statistically significant difference in the mean refusal skills of male and female pupils taught with the MITA. © The Author(s) 2014.

Tracking the allocation of attention using human pupillary oscillations

PubMed Central

Naber, Marnix; Alvarez, George A.; Nakayama, Ken

2013-01-01

The muscles that control the pupil are richly innervated by the autonomic nervous system. While there are central pathways that drive pupil dilations in relation to arousal, there is no anatomical evidence that cortical centers involved with visual selective attention innervate the pupil. In this study, we show that such connections must exist. Specifically, we demonstrate a novel Pupil Frequency Tagging (PFT) method, where oscillatory changes in stimulus brightness over time are mirrored by pupil constrictions and dilations. We find that the luminance–induced pupil oscillations are enhanced when covert attention is directed to the flicker stimulus and when targets are correctly detected in an attentional tracking task. These results suggest that the amplitudes of pupil responses closely follow the allocation of focal visual attention and the encoding of stimuli. PFT provides a new opportunity to study top–down visual attention itself as well as identifying the pathways and mechanisms that support this unexpected phenomenon. PMID:24368904

The pupil as an indicator of unconscious memory: Introducing the pupil priming effect.

PubMed

Gomes, Carlos Alexandre; Montaldi, Daniela; Mayes, Andrew

2015-06-01

We explored whether object behavioral priming and pupil changes occur in the absence of recognition memory. Experiment 1 found behavioral priming for unrecognized objects (Ms) regardless of whether they had been encoded perceptually or conceptually. Using the same perceptual encoding task, Experiment 2 showed greater pupil dilation for Ms than for correct rejections of unstudied objects (CRs) when reaction times were matched. In Experiment 3, there was relatively less pupil dilation for Ms than for similarly matched CRs when objects had been encoded conceptually. Mean/peak pupil dilation for CRs, but not Ms, increased in Experiment 3, in which novelty expectation was also reduced, and the pupillary time course for both Ms and CRs was distinct in the two experiments. These findings indicate that both behavioral and pupil memory occur for studied, but unrecognized stimuli, and suggest that encoding and novelty expectation modulate pupillary memory responses. © 2015 Society for Psychophysiological Research.

Two-path plasmonic interferometer with integrated detector

DOEpatents

Dyer, Gregory Conrad; Shaner, Eric A.; Aizin, Gregory

2016-03-29

An electrically tunable terahertz two-path plasmonic interferometer with an integrated detection element can down convert a terahertz field to a rectified DC signal. The integrated detector utilizes a resonant plasmonic homodyne mixing mechanism that measures the component of the plasma waves in-phase with an excitation field that functions as the local oscillator in the mixer. The plasmonic interferometer comprises two independently tuned electrical paths. The plasmonic interferometer enables a spectrometer-on-a-chip where the tuning of electrical path length plays an analogous role to that of physical path length in macroscopic Fourier transform interferometers.

Cyberbullying: Its Nature and Impact in Secondary School Pupils

ERIC Educational Resources Information Center

Smith, Peter K.; Mahdavi, Jess; Carvalho, Manuel; Fisher, Sonja; Russell, Shanette; Tippett, Neil

2008-01-01

Background: Cyberbullying describes bullying using mobile phones and the internet. Most previous studies have focused on the prevalence of text message and email bullying. Methods: Two surveys with pupils aged 11-16 years: (1) 92 pupils from 14 schools, supplemented by focus groups; (2) 533 pupils from 5 schools, to assess the generalisability of…

Assisting Pupils in Mathematics Achievement (The Common Core Standards)

ERIC Educational Resources Information Center

Ediger, Marlow

2011-01-01

Mathematics teachers must expect reasonably high standards of achievement from pupils. Too frequently, pupils attain at a substandard level and more optimal achievement is necessary. Thus, pupils should have self esteem needs met in the school and classroom setting. Thus, learners feel that mathematics is worthwhile and effort must be put forth to…

High School Pupils' Attitudes and Self-Efficacy of Using Mobile Devices

ERIC Educational Resources Information Center

Nikolopoulou, Kleopatra; Gialamas, Vasilis

2017-01-01

This paper regards a study aiming to investigate junior high school pupils' attitudes and self-efficacy of using mobile devices. A 25-item questionnaire was administered to 260 pupils aged 12-15 years old, in Greece. Pupils' attitudes were positive, and four factors were extracted, "perceived usefulness", "affection",…

Relationship among Demographic Variables and Pupils' Reasoning Ability

ERIC Educational Resources Information Center

Tella, Adeyinka; Tella, Adedeji; Adika, L. O.; Toyobo, Majekodunmi Oluwole

2008-01-01

Introduction: Pupils reasoning ability is a sine-qua-non to the evaluation of their performance in learning and an indicator of their potential predictors of future performance. Method: The study examined the relationship among demographic variables and reasoning ability of primary school pupils. It drew four hundred pupils from ten (10)…

Pupil Inquiry Behavior Analysis and Change Activity. Interim Project Report.

ERIC Educational Resources Information Center

Manion, Raymond C.

This interim report discusses progress toward three major goals of the Pupil Inquiry Behavior Analysis and Change Activity: increased pupil inquiry, changed teacher behavior to facilitate pupil inquiry, and the development of a 32-week course of instruction to provide for these behavioral changes. Data currently available deals with the emotional…

Pupil Control As an Institutional Pattern.

ERIC Educational Resources Information Center

Longo, Paul

This study of pupil control attitudes was based on the assumption that public school teachers and college education instructors hold divergent views on pupil control. These divergent views would then be imposed on the preservice teachers. The Pupil Control Ideology (PCI) Scale and the Dogmatism Scale, Form E, were randomly distributed to 100…

Some Comments on Inquiries on Schools and Pupil Control.

ERIC Educational Resources Information Center

Willower, Donald J.

This speech, by the co-author of a bibliography of studies of pupil control, reviews literature on that subject, differentiating between studies on Pupil Control Ideology (PCI) and Pupil Control Behavior (PCB), describing instances of their interrelationship, and weighing the various merits of PCI and PCB instruments. The author concludes that…

Educators' Pupil-Control Ideology as a Predictor of Educator's Reactions to Pupil Disruptive Behavior.

ERIC Educational Resources Information Center

Lunenburg, Fred C.

Given the importance of pupil control in the school's social system, it would seem reasonable to predict a significant relationship between educators' pupil control ideology and their reactions to disruptive behavior incidents. This study examines whether humanistically oriented educators would prefer to levy less punitive measures on disruptive…

Consulting Pupils about Classroom Teaching and Learning: Policy, Practice and Response in One School

ERIC Educational Resources Information Center

Morgan, Bethan

2011-01-01

This article reports on an ESRC (Economic and Social Research Council) doctoral study which investigated how teachers consulted pupils about teaching and learning in classrooms. Interest in consulting pupils has increased over the last decade; existing research suggests pupils have valuable perspectives on teaching and learning which teachers can…

Learning a Musical Instrument: The Influence of Interpersonal Interaction on Outcomes for School-Aged Pupils

ERIC Educational Resources Information Center

Creech, Andrea; Hallam, Susan

2011-01-01

Researchers in recent years have increasingly placed an emphasis on seeking pupils' perceptions of educational settings. Alongside this shift towards attaching value to the pupil viewpoint has been a growing interest concerning how interpersonal relationships, manifested as control or responsiveness between teachers and pupils or parents and…

Assistance to Pupils with Physical Disabilities in Regular Schools: Promoting Inclusion or Creating Dependency?

ERIC Educational Resources Information Center

Egilson, Snaefridur Thora; Traustadottir, Rannveig

2009-01-01

Drawing on the perspectives of pupils with physical disabilities, their parents and teachers, this study explored the adult support provided to pupils with physical disabilities in regular schools. Data were collected through observations at schools and qualitative interviews. In all, 49 individuals participated in this study: 14 pupils with…

Interferometer for measuring dynamic corneal topography

NASA Astrophysics Data System (ADS)

Micali, Jason Daniel

The cornea is the anterior most surface of the eye and plays a critical role in vision. A thin fluid layer, the tear film, coats the outer surface of the cornea and serves to protect, nourish, and lubricate the cornea. At the same time, the tear film is responsible for creating a smooth continuous surface where the majority of refraction takes place in the eye. A significant component of vision quality is determined by the shape of the cornea and stability of the tear film. It is desirable to possess an instrument that can measure the corneal shape and tear film surface with the same accuracy and resolution that is currently performed on common optical elements. A dual interferometer system for measuring the dynamic corneal topography is designed, built, and verified. The completed system is validated by testing on human subjects. The system consists of two co-aligned polarization splitting Twyman-Green interferometers designed to measure phase instantaneously. The primary interferometer measures the surface of the tear film while the secondary interferometer simultaneously tracks the absolute position of the cornea. Eye motion, ocular variation, and a dynamic tear film surface will result in a non-null configuration of the surface with respect to the interferometer system. A non-null test results in significant interferometer induced errors that add to the measured phase. New algorithms are developed to recover the absolute surface topography of the tear film and corneal surface from the simultaneous interferometer measurements. The results are high-resolution and high-accuracy surface topography measurements of the in vivo cornea that are captured at standard camera frame rates. This dissertation will cover the development and construction of an interferometer system for measuring the dynamic corneal topography of the human eye. The discussion starts with the completion of an interferometer for measuring the tear film. The tear film interferometer is part of an ongoing research project that has spanned multiple dissertations. For this research, the instrument was tested on human subjects and resulted in refinements to the interferometer design. The final configuration of the tear film interferometer and results from human subjects testing are presented. Feedback from this instrument was used to support the development and construction of the interferometric corneal topographer system. A calibration is performed on the instrument, and then verified against simulated eye surfaces. Finally, the instrument is validated by testing on human subjects. The result is an interferometer system that can non-invasively measure the dynamic corneal topography with greater accuracy and resolution than existing technologies.

The online behavior of pupils with visual impairment: A preliminary report.

PubMed

Wrzesińska, Magdalena; Tabała, Klaudia; Stecz, Patryk

2016-10-01

Young people with special educational needs are also users of new media. The aim of the study was to determine whether pupils with visual impairment spend more time on Internet use than pupils without visual impairment and whether youngsters from the study group are engaged in behaviors which could increase risk of problematic Internet use. The study is based on a total of 191 pupils: a study group of 66 partially-sighted pupils and a control group comprised 125 pupils who do not have visual impairment. A self-report questionnaire was constructed for the needs of this study. Pupils with visual impairment spent significantly less time on Internet use than their peers from the reference groups. Twice as many pupils from the study group as controls reported no symptoms suggesting potentially problematic Internet use. In addition, the study group more frequently used online social networking services and e-mails or used the Internet for assignments. Little difference exists between students with visual impairment and those without with regard to Internet use. Copyright © 2016 Elsevier Inc. All rights reserved.

Improving progression and continuity from primary to secondary science: Pupils' reactions to bridging work

NASA Astrophysics Data System (ADS)

Braund, Martin; Hames, Vicky

2005-07-01

This article reports research from a project set up to implement ‘bridging work’ in science in England. Group interviews of 59 pupils in Year 6 (at the end of primary school) and 48 pupils in Year 7 (at beginning of secondary school) were carried out after pupils had completed bridging work. Twenty-six of this sample were the same pupils. Semi-structured interviews were carried out in groups to ascertain: their aspirations and fears concerning secondary science, their reactions to bridging work and their memories of investigations. Year 6 pupils were positive about studying science at secondary school and remained so after transfer. Pupils' reactions to bridging at both ages were very positive. Findings challenge recent critiques of bridging. The lack of progression in pupils' communication about the variables and findings from investigations suggest that the planned progression of work was not recognized by some teachers. Bridging work alone may not guarantee improved progression and continuity in science, but as part of a carefully planned and structured programme of collaboration it has merit.

Secondary school pupils' perceptions of physics

NASA Astrophysics Data System (ADS)

Barmby, Patrick; Defty, Neil

2006-11-01

This paper describes the analysis of data collected by Durham University’s YELLIS project, over the period of 1999 to 2004. Included in this data was the degree to which pupils in England at the end of their secondary education ‘liked’ or ‘disliked’ different subjects, and their expected examination grades in these subjects. The authors’ study focused on the perceptions of pupils in the science subjects of biology, chemistry and physics. Using the available data, they were able to analyse the perceptions of a large number of pupils (e.g. 9827 pupils in 2004) who took examinations in the separate sciences. The study found that physics was perceived as the least popular science, particularly by female pupils. We also found that the expected grade in a particular science subject correlated quite strongly (Spearman’s rho of around 0.5) with the liking of that subject. These expected grades were found to be the lowest in physics, again particularly for female pupils. The authors therefore concluded that in order to redress the gender imbalance in physics, they need to tackle this problem that physics is perceived as difficult by female pupils.

Genotyping-by-sequencing to re-map QTL for type II Fusarium head blight and leaf rust resistance in a wheat-tall wheatgrass introgression recombinant inbred population

USDA-ARS?s Scientific Manuscript database

Fusarium graminaerum (Fusarium head blight; FHB) and Puccinia recondita Roberge ex Desmaz. f. sp. tritici Eriks. & E. Henn (leaf rust; LR) are two major fungal pathogens threatening the wheat crop; consequently identifying resistance genes from various sources is always of importance to wheat breede...

Reinventing Institutional Space: Remapping the Geography of Labor in English Studies.

ERIC Educational Resources Information Center

Swilky, Jody; Mahala, Dan

Discussions of reform in English studies typically focus on ideology. The focus of this paper puts the spotlight on the intended effects of classroom practice on students, on whatever is integral and valuable about the instructors' work as it appears to them. But there is also a geographical context that makes the work mean differently as it…

Switch Hands! Mapping Proactive and Reactive Cognitive Control across the Life Span

ERIC Educational Resources Information Center

Van Gerven, Pascal W. M.; Hurks, Petra P. M.; Bovend'Eerdt, Thamar J. H.; Adam, Jos J.

2016-01-01

We investigated the effects of age on proactive and reactive cognitive control in a large population sample of 809 individuals, ranging in age between 5 and 97 years. For that purpose, we used an anticue paradigm, which required a consistent remapping of cue location and response hand: Left-sided cues required right-hand responses and vice versa.…

Improved Remapping Processor For Digital Imagery

NASA Technical Reports Server (NTRS)

Fisher, Timothy E.

1991-01-01

Proposed digital image processor improved version of Programmable Remapper, which performs geometric and radiometric transformations on digital images. Features include overlapping and variably sized preimages. Overcomes some of limitations of image-warping circuit boards implementing only those geometric tranformations expressible in terms of polynomials of limited order. Also overcomes limitations of existing Programmable Remapper and made to perform transformations at video rate.

Research priorities and plans for the International Space Station-results of the 'REMAP' Task Force

NASA Technical Reports Server (NTRS)

Kicza, M.; Erickson, K.; Trinh, E.

2003-01-01

Recent events in the International Space Station (ISS) Program have resulted in the necessity to re-examine the research priorities and research plans for future years. Due to both technical and fiscal resource constraints expected on the International Space Station, it is imperative that research priorities be carefully reviewed and clearly articulated. In consultation with OSTP and the Office of Management and budget (OMB), NASA's Office of Biological and Physical Research (OBPR) assembled an ad-hoc external advisory committee, the Biological and Physical Research Maximization and Prioritization (REMAP) Task Force. This paper describes the outcome of the Task Force and how it is being used to define a roadmap for near and long-term Biological and Physical Research objectives that supports NASA's Vision and Mission. Additionally, the paper discusses further prioritizations that were necessitated by budget and ISS resource constraints in order to maximize utilization of the International Space Station. Finally, a process has been developed to integrate the requirements for this prioritized research with other agency requirements to develop an integrated ISS assembly and utilization plan that maximizes scientific output. c2003 American Institute of Aeronautics and Astronautics. Published by Elsevier Science Ltd. All rights reserved.

An adaptive moving mesh method for two-dimensional ideal magnetohydrodynamics

NASA Astrophysics Data System (ADS)

Han, Jianqiang; Tang, Huazhong

2007-01-01

This paper presents an adaptive moving mesh algorithm for two-dimensional (2D) ideal magnetohydrodynamics (MHD) that utilizes a staggered constrained transport technique to keep the magnetic field divergence-free. The algorithm consists of two independent parts: MHD evolution and mesh-redistribution. The first part is a high-resolution, divergence-free, shock-capturing scheme on a fixed quadrangular mesh, while the second part is an iterative procedure. In each iteration, mesh points are first redistributed, and then a conservative-interpolation formula is used to calculate the remapped cell-averages of the mass, momentum, and total energy on the resulting new mesh; the magnetic potential is remapped to the new mesh in a non-conservative way and is reconstructed to give a divergence-free magnetic field on the new mesh. Several numerical examples are given to demonstrate that the proposed method can achieve high numerical accuracy, track and resolve strong shock waves in ideal MHD problems, and preserve divergence-free property of the magnetic field. Numerical examples include the smooth Alfvén wave problem, 2D and 2.5D shock tube problems, two rotor problems, the stringent blast problem, and the cloud-shock interaction problem.

Scalability study of parallel spatial direct numerical simulation code on IBM SP1 parallel supercomputer

NASA Technical Reports Server (NTRS)

Hanebutte, Ulf R.; Joslin, Ronald D.; Zubair, Mohammad

1994-01-01

The implementation and the performance of a parallel spatial direct numerical simulation (PSDNS) code are reported for the IBM SP1 supercomputer. The spatially evolving disturbances that are associated with laminar-to-turbulent in three-dimensional boundary-layer flows are computed with the PS-DNS code. By remapping the distributed data structure during the course of the calculation, optimized serial library routines can be utilized that substantially increase the computational performance. Although the remapping incurs a high communication penalty, the parallel efficiency of the code remains above 40% for all performed calculations. By using appropriate compile options and optimized library routines, the serial code achieves 52-56 Mflops on a single node of the SP1 (45% of theoretical peak performance). The actual performance of the PSDNS code on the SP1 is evaluated with a 'real world' simulation that consists of 1.7 million grid points. One time step of this simulation is calculated on eight nodes of the SP1 in the same time as required by a Cray Y/MP for the same simulation. The scalability information provides estimated computational costs that match the actual costs relative to changes in the number of grid points.

Cooperative learning in science: intervention in the secondary school

NASA Astrophysics Data System (ADS)

Topping, K. J.; Thurston, A.; Tolmie, A.; Christie, D.; Murray, P.; Karagiannidou, E.

2011-04-01

The use of cooperative learning in secondary school is reported - an area of considerable concern given attempts to make secondary schools more interactive and gain higher recruitment to university science courses. In this study the intervention group was 259 pupils aged 12-14 years in nine secondary schools, taught by 12 self-selected teachers. Comparison pupils came from both intervention and comparison schools (n = 385). Intervention teachers attended three continuing professional development days, in which they received information, engaged with resource packs and involved themselves in cooperative learning. Measures included both general and specific tests of science, attitudes to science, sociometry, self-esteem, attitudes to cooperative learning and transferable skills (all for pupils) and observation of implementation fidelity. There were increases during cooperative learning in pupil formulation of propositions, explanations and disagreements. Intervened pupils gained in attainment, but comparison pupils gained even more. Pupils who had experienced cooperative learning in primary school had higher pre-test scores in secondary education irrespective of being in the intervention or comparison group. On sociometry, comparison pupils showed greater affiliation to science work groups for work, but intervention pupils greater affiliation to these groups at break and out of school. Other measures were not significant. The results are discussed in relation to practice and policy implications.

Inferior ectopic pupil and typical ocular coloboma in RCS rats.

PubMed

Tsuji, Naho; Ozaki, Kiyokazu; Narama, Isao; Matsuura, Tetsuro

2011-08-01

Ocular coloboma is sometimes accompanied by corectopia in humans and therefore ectopic pupil may indicate ocular coloboma in experimental animals. The RCS strain of rats has a low incidence of microphthalmia. We found that inferior ectopic pupil is associated exclusively with small-sized eyes in this strain. The objective of the current study was to evaluate whether inferior ectopic pupil is associated with iridal coloboma and other types of ocular coloboma in RCS rats. Both eyes of RCS rats were examined clinically, and those with inferior ectopic pupils underwent morphologic and morphometric examinations. In a prenatal study, coronal serial sections of eyeballs from fetuses at gestational day 16.5 were examined by using light microscopy. Ectopic pupils in RCS rats were found exclusively in an inferior position, where the iris was shortened. Fundic examination revealed severe chorioretinal coloboma in all cases of inferior ectopic pupil. The morphologic characteristics closely resembled those of chorioretinal coloboma in humans. Histopathologic examination of primordia showed incomplete closure of the optic fissure in 4 eyeballs of RCS fetuses. Neither F(1) rats nor N(2) (progeny of RCS × BN matings) displayed any ocular anomalies, including ectopic pupils. The RCS strain is a suitable model for human ocular coloboma, and inferior ectopic pupil appears to be a strong indicator of ocular coloboma.

Inferior Ectopic Pupil and Typical Ocular Coloboma in RCS Rats

PubMed Central

Tsuji, Naho; Ozaki, Kiyokazu; Narama, Isao; Matsuura, Tetsuro

2011-01-01

Ocular coloboma is sometimes accompanied by corectopia in humans and therefore ectopic pupil may indicate ocular coloboma in experimental animals. The RCS strain of rats has a low incidence of microphthalmia. We found that inferior ectopic pupil is associated exclusively with small-sized eyes in this strain. The objective of the current study was to evaluate whether inferior ectopic pupil is associated with iridal coloboma and other types of ocular coloboma in RCS rats. Both eyes of RCS rats were examined clinically, and those with inferior ectopic pupils underwent morphologic and morphometric examinations. In a prenatal study, coronal serial sections of eyeballs from fetuses at gestational day 16.5 were examined by using light microscopy. Ectopic pupils in RCS rats were found exclusively in an inferior position, where the iris was shortened. Fundic examination revealed severe chorioretinal coloboma in all cases of inferior ectopic pupil. The morphologic characteristics closely resembled those of chorioretinal coloboma in humans. Histopathologic examination of primordia showed incomplete closure of the optic fissure in 4 eyeballs of RCS fetuses. Neither F1 rats nor N2 (progeny of RCS × BN matings) displayed any ocular anomalies, including ectopic pupils. The RCS strain is a suitable model for human ocular coloboma, and inferior ectopic pupil appears to be a strong indicator of ocular coloboma. PMID:22330254

The Predictive Role of Maternal Parenting and Stress on Pupils' Bullying involvement.

PubMed

Alizadeh Maralani, Fatemeh; Mirnasab, Mirmahmoud; Hashemi, Touraj

2016-10-01

The link between inappropriate parenting style and both bullying and victimization is well documented. However, it is not clear as to which kind of parenting style is associated with victimization. Furthermore, no studies have yet been conducted regarding the role of parental stress in bullying and victimization. This study aimed to examine the role of parenting styles and maternal stress in pupils' bullying and victimization. A total of 300 primary school pupils, enrolled in fourth and fifth grades, participated in the study. Initially, 100 noninvolved pupils were randomly selected using a multistage cluster sampling method. Then using a screening method, 100 bully pupils and 100 victimized peers were selected. Olweus Bullying Scale and teacher nomination were administered for screening these pupils. Baumrind Parenting Style Questionnaire and revised version of Abidin Parental Stress Index (short form) were also applied to all pupils in the study. Data were analyzed using discriminant function analysis. The findings showed that (a) with regard to parenting styles, significant differences were found among groups. Authoritarian parenting style could significantly predict pupils' bullying behavior, whereas victimization was predictable in families with permissive parenting style. In addition, noninvolved pupils were predicted to have authoritative parenting style. (b) Considering maternal stress, significant differences were observed across groups. Parents of bullies and victims were predicted to have higher maternal stress than noninvolved pupils. The implications of the study in relation to the role of mothers in bullying and victimization are discussed.

The WIND-HAARP-HIPAS Interferometer Experiment

DTIC Science & Technology

1999-04-22

Naval Research Laboratory Washington, DC 20375-5320 NRL/MR/6750--99-8349 The WIND- HAARP -HIPAS Interferometer Experiment P. RODRIGUEZ AND M. J...1999 3. REPORT TYPE AND DATES COVERED Interim Report 4. TITLE AND SUBTITLE The WIND- HAARP -HIPAS Interferometer Experiment 5. FUNDING NUMBERS JO...frequency transmitting facilities in a bistatic, interferometer mode. The HAARP and HIPAS facilities in Alaska radiated at 4525 kHz with total combined

Polarisation Measurement with a Dual Beam Interferometer (CATSI). Exploratory Results and Preliminary Phenomenological Analysis

DTIC Science & Technology

2006-06-01

Polarisation measurement with a dual beam interferometer (CATSI) Exploratory results and preliminary phenomenological analysis H. Lavoie J.-M... Polarisation measurement with a dual beam interferometer (CATSI) Exploratory results and preliminary phenomenological analysis H. Lavoie J.-M. Thériault... Polarisation measurement with a dual beam interferometer (CATSI) - Exploratory results and preliminary phenomenological analysis. ECR 2004-372. DRDC Valcartier

Interactive Apps Promote Learning of Basic Mathematics in Children With Special Educational Needs and Disabilities

PubMed Central

Pitchford, Nicola J.; Kamchedzera, Elizabeth; Hubber, Paula J.; Chigeda, Antonie L.

2018-01-01

Interactive apps delivered on touch-screen tablets can be effective at supporting the acquisition of basic skills in mainstream primary school children. This technology may also be beneficial for children with Special Educational Needs and Disabilities (SEND) as it can promote high levels of engagement with the learning task and an inclusive learning environment. However, few studies have measured extent of learning for SEND pupils when using interactive apps, so it has yet to be determined if this technology is effective at raising attainment for these pupils. We report the first observational study of a group of 33 pupils with SEND from two primary schools in Malawi that are implementing a new digital technology intervention which uses touch-screen tablets to deliver interactive apps designed to teach basic mathematical skills. The apps contain topics that align to the national curriculum. To assess learning gains, rate of progress (minutes per topic) for each pupil was determined by calculating the average time taken to complete a topic. Progress rate was then correlated with teacher ratings of extent of disability and independent ratings of pupil engagement with the apps. Results showed SEND pupils could interact with the apps and all pupils passed at least one topic. Average progress rate for SEND pupils was twice as long as mainstream peers. Stepwise regression revealed extent of disability significantly predicted progress rate. Further exploratory correlations revealed pupils with moderate to severe difficulties with hearing and/or language made slower progress through the apps than those with greater functionality in these two domains because the use of verbal instructions within the apps limited their capacity to learn. This original quantitative analysis demonstrates that interactive apps can raise learning standards in pupils with SEND but may have limited utility for pupils with severe difficulties. Software modifications are needed to address specific areas of difficulty preventing pupils from progressing. PMID:29559940

Interactive Apps Promote Learning of Basic Mathematics in Children With Special Educational Needs and Disabilities.

PubMed

Pitchford, Nicola J; Kamchedzera, Elizabeth; Hubber, Paula J; Chigeda, Antonie L

2018-01-01

Interactive apps delivered on touch-screen tablets can be effective at supporting the acquisition of basic skills in mainstream primary school children. This technology may also be beneficial for children with Special Educational Needs and Disabilities (SEND) as it can promote high levels of engagement with the learning task and an inclusive learning environment. However, few studies have measured extent of learning for SEND pupils when using interactive apps, so it has yet to be determined if this technology is effective at raising attainment for these pupils. We report the first observational study of a group of 33 pupils with SEND from two primary schools in Malawi that are implementing a new digital technology intervention which uses touch-screen tablets to deliver interactive apps designed to teach basic mathematical skills. The apps contain topics that align to the national curriculum. To assess learning gains, rate of progress (minutes per topic) for each pupil was determined by calculating the average time taken to complete a topic. Progress rate was then correlated with teacher ratings of extent of disability and independent ratings of pupil engagement with the apps. Results showed SEND pupils could interact with the apps and all pupils passed at least one topic. Average progress rate for SEND pupils was twice as long as mainstream peers. Stepwise regression revealed extent of disability significantly predicted progress rate. Further exploratory correlations revealed pupils with moderate to severe difficulties with hearing and/or language made slower progress through the apps than those with greater functionality in these two domains because the use of verbal instructions within the apps limited their capacity to learn. This original quantitative analysis demonstrates that interactive apps can raise learning standards in pupils with SEND but may have limited utility for pupils with severe difficulties. Software modifications are needed to address specific areas of difficulty preventing pupils from progressing.

Multi-level aspects of social cohesion of secondary schools and pupils' feelings of safety.

PubMed

Mooij, Ton; Smeets, Ed; de Wit, Wouter

2011-09-01

BACKGROUND. School safety and corresponding feelings of both pupils and school staff are beginning to receive more and more attention. The social cohesion characteristics of a school may be useful in promoting feelings of safety, particularly in pupils. AIMS. To conceptualize theoretically, and check empirically a two-level model of social cohesion between and within schools, in order to explain a pupil's feelings of safety at school. SAMPLES. Data were collected aided by a national Dutch survey in secondary education carried out via the Internet. In 2008, digital questionnaires were completed by about 78,800 pupils, 6,200 teachers and educational support staff, and 600 school managers. METHODS. Data were checked for reliability and representativity. Social cohesion was indicated by self-reported measures of individual pupils and by aggregating scale and item scores of school managers, teachers, and other support staff within schools. Multi-level analysis using individual pupil data and school-level data was performed using MLwiN. RESULTS. A pupil's age, educational attainment level, experience of mild physical violence, prosocial rules of conduct and joint control of these rules, and school measures against playing truant, show positive influences on a pupil's feelings of safety at school. Negative influences are exerted by not feeling most at home in The Netherlands, peers taking drugs and weapons into school, and by experiencing social violence, severe physical violence, and sexual violence. Negative school effects exist simultaneously in severe physical violence experienced by teachers and other staff, and in curriculum differentiation applied by teachers and other staff; a positive school effect is school size. Some interaction effects between pupil and school-level variables were explored. CONCLUSIONS. The variance at school level is relatively low compared with the variance at pupil level. However, a much higher percentage of variance at school level than at pupil level is explained with respect to the pupils' feelings of safety at school. The resulting two-level model also reflects the streaming of pupils in Dutch secondary schools. To improve school safety, the national results emphasize the need to enhance prosocial behaviour rules and to enhance the shared control of these rules between teachers and pupils. They also emphasize the need for the school to take measures that prevent truancy and redefine curriculum differentiation procedures. National educational policy and research can combine efforts to assist schools in developing reliable and valid procedures to increase effectively safety in and around schools. ©2010 The British Psychological Society.

SU(1,1)-type light-atom-correlated interferometer

NASA Astrophysics Data System (ADS)

Ma, Hongmei; Li, Dong; Yuan, Chun-Hua; Chen, L. Q.; Ou, Z. Y.; Zhang, Weiping

2015-08-01

The quantum correlation of light and atomic collective excitation can be used to compose an SU(1,1)-type hybrid light-atom interferometer, where one arm in the optical SU(1,1) interferometer is replaced by the atomic collective excitation. The phase-sensing probes include not only the photon field but also the atomic collective excitation inside the interferometer. For a coherent squeezed state as the phase-sensing field, the phase sensitivity can approach the Heisenberg limit under the optimal conditions. We also study the effects of the loss of light field and the dephasing of atomic excitation on the phase sensitivity. This kind of active SU(1,1) interferometer can also be realized in other systems, such as circuit quantum electrodynamics in microwave systems, which provides a different method for basic measurement using the hybrid interferometers.

Experimental generalized quantum suppression law in Sylvester interferometers

NASA Astrophysics Data System (ADS)

Viggianiello, Niko; Flamini, Fulvio; Innocenti, Luca; Cozzolino, Daniele; Bentivegna, Marco; Spagnolo, Nicolò; Crespi, Andrea; Brod, Daniel J.; Galvão, Ernesto F.; Osellame, Roberto; Sciarrino, Fabio

2018-03-01

Photonic interference is a key quantum resource for optical quantum computation, and in particular for so-called boson sampling devices. In interferometers with certain symmetries, genuine multiphoton quantum interference effectively suppresses certain sets of events, as in the original Hong–Ou–Mandel effect. Recently, it was shown that some classical and semi-classical models could be ruled out by identifying such suppressions in Fourier interferometers. Here we propose a suppression law suitable for random-input experiments in multimode Sylvester interferometers, and verify it experimentally using 4- and 8-mode integrated interferometers. The observed suppression occurs for a much larger fraction of input–output combinations than what is observed in Fourier interferometers of the same size, and could be relevant to certification of boson sampling machines and other experiments relying on bosonic interference, such as quantum simulation and quantum metrology.

Detection, Evaluation, and Optimization of Optical Signals Generated by Fiber Optic Bragg Gratings Under Dynamic Excitations

NASA Technical Reports Server (NTRS)

Adamovsky, Grigory; Lekki, John; Lock, James A.

2002-01-01

The dynamic response of a fiber optic Bragg grating to mechanical vibrations is examined both theoretically and experimentally. The theoretical expressions describing the consequences of changes in the grating's reflection spectrum are derived for partially coherent beams in an interferometer. The analysis is given in terms of the dominant wavelength, optical bandwidth, and optical path difference of the interfering signals. Changes in the reflection spectrum caused by a periodic stretching and compression of the grating were experimentally measured using an unbalanced Michelson interferometer, a Michelson interferometer with a non-zero optical path difference. The interferometer's sensitivity to changes in dominant wavelength of the interfering beams was measured as a function of interferometer unbalance and was compared to theoretical predictions. The theoretical analysis enables the user to determine the optimum performance for an unbalanced interferometer.

Numerical simulation and experimental verification of extended source interferometer

NASA Astrophysics Data System (ADS)

Hou, Yinlong; Li, Lin; Wang, Shanshan; Wang, Xiao; Zang, Haijun; Zhu, Qiudong

2013-12-01

Extended source interferometer, compared with the classical point source interferometer, can suppress coherent noise of environment and system, decrease dust scattering effects and reduce high-frequency error of reference surface. Numerical simulation and experimental verification of extended source interferometer are discussed in this paper. In order to provide guidance for the experiment, the modeling of the extended source interferometer is realized by using optical design software Zemax. Matlab codes are programmed to rectify the field parameters of the optical system automatically and get a series of interferometric data conveniently. The communication technique of DDE (Dynamic Data Exchange) was used to connect Zemax and Matlab. Then the visibility of interference fringes can be calculated through adding the collected interferometric data. Combined with the simulation, the experimental platform of the extended source interferometer was established, which consists of an extended source, interference cavity and image collection system. The decrease of high-frequency error of reference surface and coherent noise of the environment is verified. The relation between the spatial coherence and the size, shape, intensity distribution of the extended source is also verified through the analysis of the visibility of interference fringes. The simulation result is in line with the result given by real extended source interferometer. Simulation result shows that the model can simulate the actual optical interference of the extended source interferometer quite well. Therefore, the simulation platform can be used to guide the experiment of interferometer which is based on various extended sources.

Pupils

ERIC Educational Resources Information Center

Garber, Lee O.; Seitz, Reynolds C.

1971-01-01

Discusses recent court litigation concerning legal rights and responsibilities of pupils covering procedural due process, grooming and appearance, regulation of speech and publications, liability for pupil injuries, and racial integration. (JF)

METHODS OF DETERMINING PUPIL READINESS FOR SPECIFIC UNITS OF INSTRUCTION PRESENTED THROUGH SIMULATED ENVIRONMENT MEDIA.

ERIC Educational Resources Information Center

PLUMPTON, RUSSEL A.

THE METHODS FOR DETERMINING PUPIL READINESS WERE STUDIED TO DEVELOP CRITERIA FOR PUPIL PARTICIPATION IN SIMULATED ENVIRONMENT LEARNING UNITS. THE LEARNING UNITS WERE SUBPROJECTS OF COOPERATIVE RESEARCH PROJECT NUMBER 1948 (ED 003 024). EACH OF THREE UNITS IN THE PROJECT WAS EXAMINED FOR PUPIL READINESS. TEST BATTERIES WERE ASSEMBLED AND…

Sticky Assessments--The Impact of Teachers' Grading Standard on Pupils' School Performance

ERIC Educational Resources Information Center

Keller, Tamás

2016-01-01

This paper argues that school grades cannot be interpreted solely as a reward for a given school performance, since they also reflect teachers' assessments of pupils. A teacher's evaluation of a pupil's performance, as reflected in the grade awarded, might influence the effort that the pupil invests in learning. Grades might therefore serve as…

Learning Stations in the Social Studies

ERIC Educational Resources Information Center

Ediger, Marlow

2011-01-01

The use of learning stations is an approach to meet needs of pupils in achievement. Here, pupils may make choices in terms of what to learn. From a learning station, a pupil may select learning activities to complete, be they individual or committee endeavors. Activities might also be chosen on the basis of learning styles. A pupil may prefer to…

Tomorrow's Workforce: School Pupils' Views of a Career in Hospitality. Research Report.

ERIC Educational Resources Information Center

Tregaskis, Olga; And Others

A survey involving 1,024 secondary pupils and 22 career educators from schools throughout the United Kingdom collected information on pupils' perceptions of entering the hotel and catering industry as a career. The research looked in detail at the job expectations of pupils, the status they associated with hotel and catering and nonhotel and…

What Happens When I Write? Pupils' Writing about Writing

ERIC Educational Resources Information Center

Barbeiro, Luis Filipe

2011-01-01

This article presents pupils' awareness of writing as elicited through a metawriting task, in other words a task in which pupils from the third, fourth and sixth forms (grades) were required to write about writing. The analysis of the texts revealed the pupils' increasing ability to write texts focusing on writing and on the subject's relationship…

Pupils' Perceptions of Sex and Reproductive Health Education in Primary Schools in Tanzania: A Phenomenological Study

ERIC Educational Resources Information Center

Kapinga, Orestes Silverius; Hyera, Daniel Frans

2015-01-01

This study explored pupils' perceptions of sex and reproductive health education in primary schools in Tanzania. Specifically, the study aimed at (i) exploring pupils' views on sex and reproductive health education in primary schools; (ii) determining opinions on the appropriateness of sex and reproductive health education for pupils in primary…

Entrepreneurship Education: Motivation and Effort for Pupils with Special Needs in Norwegian Compulsory School

ERIC Educational Resources Information Center

Somby, Hege Merete; Johansen, Vegard

2017-01-01

Pupil enterprises are a widespread type of entrepreneurship education. In this working method, pupils start up, manage and close a business over short period of time. National and international policy documents claim that practical working methods through the use of pupil enterprises are beneficial to increase motivation by being a realistic and…

Pupil Control Ideology as a Source of Stress: The Student Teacher's Dilemma.

ERIC Educational Resources Information Center

Jones, Dan R.

One type of adaptation made by each student teacher is the development of attitudes toward controlling pupils. The student teachers' attitudes toward pupil control may be at odds with those of other educators and this difference in attitude, particularly in the case of the cooperating teacher, can cause stress. Attitudes toward pupil control can…

Pupils' Thinking and Course Requirements in Science Teaching (EKNA). Newsletter School Research.

ERIC Educational Resources Information Center

Andersson, Bjorn; And Others

The ENKA Project is concerned with two major problem areas: the conceptions of physical and chemical phenomena, central to an upper level course, held by compulsory school pupils (grades 7-9) and the implications from descriptions of pupils' conceptions and ways of reasoning for current teaching practice. To determine conceptions held, pupils were…

Pupils' Image of "The Scientist" among Two Communities in Israel: A Comparative Study

ERIC Educational Resources Information Center

Koren, Pazit; Bar, Varda

2009-01-01

The image of "the scientist" and its effect on the willingness to be a scientist and to follow a career in science were investigated in two different cultural populations of elementary and junior high school pupils in Israel: Hebrew-speaking (secular) pupils (N = 390) and Arabic-speaking Bedouin pupils (N = 185). Five different tools…

Pupils' Attitudes toward Chemistry in Two Types of Czech Schools

ERIC Educational Resources Information Center

Kubiatko, Milan; Balatova, Kristyna; Fancovicova, Jana; Prokop, Pavol

2017-01-01

Chemistry is a school subject that is not viewed favorably among pupils. Before we can improve pupils' attitudes toward chemistry, it is important to find out the problem as to why the attitudes are relatively negative. The research was focused on Czech lower secondary and secondary grammar school pupils' attitudes to the subject of chemistry.…

Comparing Slovenian Year 8 and Year 9 Elementary School Pupils' Knowledge of Electrolyte Chemistry and Their Intrinsic Motivation

ERIC Educational Resources Information Center

Devetak, Iztok; Lorber, Erna Drofenik; Jurisevic, Mojca; Glazar, Sasa A.

2009-01-01

This study explored the differences between eight-year elementary school pupils (before the curriculum reform) and nine-year elementary school pupils (soon after the curriculum reform) in Slovenia, as regards specific chemistry knowledge and motivation to learn chemistry. Altogether, 191 elementary school pupils participated in the study. The…

What Can National Data Sets Tell Us about Inclusion and Pupil Achievement?

ERIC Educational Resources Information Center

Florian, Lani; Rouse, Martyn; Black-Hawkins, Kristine; Jull, Stephen

2004-01-01

Recent developments in the Department for Education and Skills (DfES) have produced a national pupil database (NPD) that contains information about the attainments of individual pupils. Every child in the country has been allocated a unique pupil number (UPN), which means that the academic progress of individuals can be tracked over time. It is…

Brief Report: Multilevel Analysis of School Smoking Policy and Pupil Smoking Behaviour in Wales

ERIC Educational Resources Information Center

Wiium, Nora; Burgess, Stephen; Moore, Laurence

2011-01-01

A multilevel analysis of cross-sectional data from a survey involving 1941 pupils (in grades 10 and 11) and policy indicators developed from interviews with staff from 45 secondary schools in Wales examined the hypotheses that pupil smoking prevalence would be associated with: restrictive staff and pupil smoking policies; dissemination of school…

Cooperative Group, Risk-Taking and Inclusion of Pupils with Learning Disabilities in Physical Education

ERIC Educational Resources Information Center

Andre, Amael; Louvet, Benoit; Deneuve, Pascale

2013-01-01

The aim of this research was to study the impact of cooperative learning on changes in cooperative behaviours and acceptance amongst pupils with learning disabilities related to risk-taking. One hundred and sixty-eight French first year middle school pupils participated in this study. Thirty-six pupils with learning disabilities were mainstreamed…

The Performance of Mouse Pointing and Selecting for Pupils with and without Intellectual Disabilities

ERIC Educational Resources Information Center

Lin, Yun-Lung; Chen, Ming-Chung; Chang, Yun-Ting; Yeh, Chih-Ching; Meng, Ling-Fu

2009-01-01

The purpose of this study was to compare the performance of mouse pointing and selecting in the tasks with different index of difficulty between 20 pupils with intellectual disabilities and 21 pupils without disabilities. A mouse proficiency assessment software was utilized to collect data. Pupils with intellectual disabilities executed tasks more…

Teacher Candidates Speak Out: Exploring Concerns Related to Pupil Learning and Efficacy When Learning to Teach

ERIC Educational Resources Information Center

Derosier, Sharline; Soslau, Elizabeth

2014-01-01

Research shows that teachers' efficacy relates to pupil achievement. Strong efficacy, or a self-belief that one can positively impact pupil learning, is risked when teachers develop concerns related to pupil learning. This study explored the perceived concerns of teacher candidates (N = 3) throughout an eight-week clinical field experience.…

Pupils' Self-Perceptions: The Role of Teachers' Judgment Controlling for Big-Fish-Little-Pond Effect

ERIC Educational Resources Information Center

Bressoux, Pascal; Pansu, Pascal

2016-01-01

This article aims to study the relationship between teachers' judgment and pupils' self-perceptions controlling for the big-fish-little-pond effect (BFLPE). Three studies were conducted among third-grade pupils. Study 1 (n = 585) focused on pupils' perceptions of their scholastic competence. Teachers' judgment and BFLPE were found to have an…

Comparative Study of Pupils' Academic Performance between Private and Public Primary Schools

ERIC Educational Resources Information Center

Adeyemi, Sunday B.

2014-01-01

This paper compares pupils' academic performance between the private and public primary schools. The sample, made up of 240 pupils were randomly selected from the private and public primary schools in Ilesa East and West Local Government Council Areas of Osun State, Nigeria. Two instruments were used. A structured questionnaire and Pupils'…

Constructions of Racism by British Chinese Pupils and Parents

ERIC Educational Resources Information Center

Archer, Louise; Francis, Becky

2005-01-01

British Chinese pupils stand out as a high achieving group within the British education system and yet very little theoretical or policy attention has been given to these pupils' identities and experiences of education. In this paper we consider British Chinese pupils' (and parents') reports of their experiences of racism/s and their views on the…

Linking Pupil and Teacher Competence in Reading and Mathematics in Vietnam

ERIC Educational Resources Information Center

Griffin, Patrick

2008-01-01

This article reports results derived from the national study of Grade 5 in Vietnamese primary schools in which teachers and pupils took tests in reading and mathematics. The test data were calibrated so that teacher and pupil results could be mapped onto the same continuum. Results showed that the overlapping tests for teachers and pupils were…

Pupil Researchers Generation X: Educating Pupils as Active Participants--An Investigation into Gathering Sensitive Information from Early Adolescents

ERIC Educational Resources Information Center

Symonds, Jenny E.

2008-01-01

Developmentally appropriate research techniques were uncovered by involving ten Year 7 pupils as researchers in a four-hour workshop that investigated the effectiveness of multiple methods in gathering sensitive information from early adolescents. The pupils learned about, tried and evaluated the methods of generating interview questions, peer and…

Changing Spaces, Changing Relationships: The Positive Impact of Learning Out of Doors

ERIC Educational Resources Information Center

Scott, Graham; Boyd, Margaret; Colquhoun, Derek

2013-01-01

We have used the experiences of teachers and their pupils to explore the impact of participation in a shared outdoor learning experience upon specific aspects of both the teacher/pupil and pupil/pupil relationship. Prior to their taking part in an out of classroom lesson the teachers involved in our project were relatively inexperienced in…

Pupil Mobility, Attainment and Progress in Primary School

ERIC Educational Resources Information Center

Strand, Steve; Demie, Feyisa

2006-01-01

This article presents an analysis of the association between pupil mobility and educational attainment in the 2002 national end of Key Stage 2 (KS2) tests for 11-year-old pupils in an inner London education authority. The results show that pupil mobility is strongly associated with low attainment in the end of key stage tests. However, the…

Roma Pupils' Identification with School in Slovenia and Serbia: Case Studies

ERIC Educational Resources Information Center

Macura-Milovanovic, Suncica; Munda, Milanka; Pecek, Mojca

2013-01-01

The research presented in this paper aims to challenge the belief held by some education professionals that Roma pupils do not value education. The research sample included groups of Roma pupils from two countries (Slovenia and Serbia) and from different socio-economic backgrounds. The results suggest that the majority of the pupils are aware of…

Deaf pupils' reasoning about scientific phenomena: school science as a framework for understanding or as fragments of factual knowledge.

PubMed

Molander, B O; Pedersen, S; Norell, K

2001-01-01

Many studies have been conducted on hearing pupils' understanding of science. Findings from these studies have been used as grounds for planning instruction in school science. This article reports findings from an interview study of how deaf pupils in compulsory school reason about phenomena in a science context. The results reveal that there is variation in the extent to which pupils use scientific principles for reasoning about science phenomena. For some pupils, school science seems to have little to offer as a framework for reasoning. The results also generate questions about the need in school instruction of deaf and hard-of-hearing pupils to consider the specific teaching and learning situations in a deaf environment.

Application of phase-diverse phase retrieval to wavefront sensing in non-connected complicated pupil optics

NASA Astrophysics Data System (ADS)

Mao, Heng; Wang, Xiao; Zhao, Dazun

2007-07-01

Baseline algorithm, as a tool in wavefront sensing (WFS), incorporates the phase-diverse phase retrieval (PDPR) method with hybrid-unwrapping approach to ensure a unique pupil phase estimate with high WFS accuracy even in the case of high dynamic range aberration, as long as the pupil shape is of a convex set. However, for a complicated pupil, such as that in obstructed pupil optics, the said unwrapping approach would fail owing to the fake values at points located in obstructed areas of the pupil. Thus a modified unwrapping approach that can minimize the negative effects of the obstructed areas is proposed. Simulations have shown the validity of this unwrapping approach when it is embedded in Baseline algorithm.

Joint optimization of source, mask, and pupil in optical lithography

NASA Astrophysics Data System (ADS)

Li, Jia; Lam, Edmund Y.

2014-03-01

Mask topography effects need to be taken into consideration for more advanced resolution enhancement techniques in optical lithography. However, rigorous 3D mask model achieves high accuracy at a large computational cost. This work develops a combined source, mask and pupil optimization (SMPO) approach by taking advantage of the fact that pupil phase manipulation is capable of partially compensating for mask topography effects. We first design the pupil wavefront function by incorporating primary and secondary spherical aberration through the coefficients of the Zernike polynomials, and achieve optimal source-mask pair under the condition of aberrated pupil. Evaluations against conventional source mask optimization (SMO) without incorporating pupil aberrations show that SMPO provides improved performance in terms of pattern fidelity and process window sizes.

The beam combiners of Gravity VLTI instrument: concept, development, and performance in laboratory

NASA Astrophysics Data System (ADS)

Jocou, L.; Perraut, K.; Moulin, T.; Magnard, Y.; Labeye, P.; Lapras, V.; Nolot, A.; Perrin, G.; Eisenhauer, F.; Holmes, C.; Amorim, A.; Brandner, W.; Straubmeier, C.

2014-07-01

Gravity is one of the second-generation instruments of the Very Large Telescope Interferometer that operates in the near infrared range and that is designed for precision narrow-angle astrometry and interferometric imaging. With its infrared wavefront sensors, pupil stabilization, fringe tracker, and metrology, the instrument is tailored to provide a high sensitivity, imaging with 4-millisecond resolution, and astrometry with a 10μarcsec precision. It will probe physics close to the event horizon of the Galactic Centre black hole, and allow to study mass accretion and jets in young stellar objects and active galactic nuclei, planet formation in circumstellar discs, or detect and measure the masses of black holes in massive star clusters throughout the Milky Way. As the instrument required an outstanding level of precision and stability, integrated optics has been chosen to collect and combine the four VLTI beams in the K band. A dedicated integrated optics chip glued to a fiber array has been developed. Technology breakthroughs have been mandatory to fulfill all the specifications. This paper is focused on the interferometric beam combination system of Gravity. Once the combiner concept described, the paper details the developments that have been led, the integration and the performance of the assemblies.

Static and (quasi)dynamic calibration of stroboscopic scanning white light interferometer

NASA Astrophysics Data System (ADS)

Seppä, Jeremias; Kassamakov, Ivan; Nolvi, Anton; Heikkinen, Ville; Paulin, Tor; Lassila, Antti; Hao, Ling; Hæggsröm, Edward

2013-04-01

A scanning white light interferometer can characterize out of plane features and motion in M(N)EMS devices. Like any other form and displacement measuring instrument, the scanning interferometer results should be linked to the metre definition to be comparable and unambiguous. Traceability is built up by careful error characterization and calibration of the interferometer. The main challenge in this calibration is to have a reference device producing accurate and reproducible dynamic out-of-plane displacement when submitted to standard loads. We use a flat mirror attached to a piezoelectric transducer for static and (quasi)dynamic calibration of a stroboscopic scanning light interferometer. First we calibrated the piezo-scanned flexure guided transducer stage using a symmetric differential heterodyne laser interferometer developed at the Centre for Metrology and Accreditation (MIKES). The standard uncertainty of the piezo stage motion calibration was 3.0 nm. Then we used the piezo-stage as a transfer standard to calibrate our stroboscopic interferometer whose light source was pulsed at 200 Hz and 400 Hz with 0.5% duty cycle. We measured the static position and (quasi)dynamic motion of the attached mirror relative to a reference surface. This methodology permits calibrating the vertical scale of the stroboscopic scanning white light interferometer.

Phase shifting diffraction interferometer

DOEpatents

Sommargren, Gary E.

1996-01-01

An interferometer which has the capability of measuring optical elements and systems with an accuracy of .lambda./1000 where .lambda. is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about .lambda./50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms.

Phase shifting diffraction interferometer

DOEpatents

Sommargren, G.E.

1996-08-29

An interferometer which has the capability of measuring optical elements and systems with an accuracy of {lambda}/1000 where {lambda} is the wavelength of visible light. Whereas current interferometers employ a reference surface, which inherently limits the accuracy of the measurement to about {lambda}/50, this interferometer uses an essentially perfect spherical reference wavefront generated by the fundamental process of diffraction. This interferometer is adjustable to give unity fringe visibility, which maximizes the signal-to-noise, and has the means to introduce a controlled prescribed relative phase shift between the reference wavefront and the wavefront from the optics under test, which permits analysis of the interference fringe pattern using standard phase extraction algorithms. 8 figs.

Experimental study of the mutual influence of fibre Faraday elements in a spun-fibre interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gubin, V P; Morshnev, S K; Przhiyalkovsky, Ya V

2015-08-31

An all-spun-fibre linear reflective interferometer with two linked Faraday fibre coils is studied. It is found experimentally that there is mutual influence of Faraday fibre coils in this interferometer. It manifests itself as an additional phase shift of the interferometer response, which depends on the circular birefringence induced by the Faraday effect in both coils. In addition, the interferometer contrast and magneto-optical sensitivity of one of the coils change. A probable physical mechanism of the discovered effect is the distributed coupling of orthogonal polarised waves in the fibre medium, which is caused by fibre bend in the coil. (interferometry)

An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.

2013-09-15

We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

Picometre displacement measurements using a differential Fabry-Perot optical interferometer and an x-ray interferometer

NASA Astrophysics Data System (ADS)

Çelik, Mehmet; Hamid, Ramiz; Kuetgens, Ulrich; Yacoot, Andrew

2012-08-01

X-ray interferometry is emerging as an important tool for dimensional nanometrology both for sub-nanometre measurement and displacement. It has been used to verify the performance of the next generation of displacement measuring optical interferometers within the European Metrology Research Programme project NANOTRACE. Within this project a more detailed set of comparison measurements between the x-ray interferometer and a dual channel Fabry-Perot optical interferometer (DFPI) have been made to demonstrate the capabilities of both instruments for picometre displacement metrology. The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed.

Dual surface interferometer

DOEpatents

Pardue, R.M.; Williams, R.R.

1980-09-12

A double-pass interferometer is provided which allows direct measurement of relative displacement between opposed surfaces. A conventional plane mirror interferometer may be modified by replacing the beam-measuring path cube-corner reflector with an additional quarterwave plate. The beam path is altered to extend to an opposed plane mirrored surface and the reflected beam is placed in interference with a retained reference beam split from dual-beam source and retroreflected by a reference cube-corner reflector mounted stationary with the interferometer housing. This permits direct measurement of opposed mirror surfaces by laser interferometry while doubling the resolution as with a conventional double-pass plane mirror laser interferometer system.

Dual surface interferometer

DOEpatents

Pardue, Robert M.; Williams, Richard R.

1982-01-01

A double-pass interferometer is provided which allows direct measurement of relative displacement between opposed surfaces. A conventional plane mirror interferometer may be modified by replacing the beam-measuring path cube-corner reflector with an additional quarter-wave plate. The beam path is altered to extend to an opposed plane mirrored surface and the reflected beam is placed in interference with a retained reference beam split from dual-beam source and retroreflected by a reference cube-corner reflector mounted stationary with the interferometer housing. This permits direct measurement of opposed mirror surfaces by laser interferometry while doubling the resolution as with a conventional double-pass plane mirror laser interferometer system.

Amplitude and intensity spatial interferometry; Proceedings of the Meeting, Tucson, AZ, Feb. 14-16, 1990

NASA Technical Reports Server (NTRS)

Breckinridge, Jim B. (Editor)

1990-01-01

Attention is given to such topics as ground interferometers, space interferometers, speckle-based and interferometry-based astronomical observations, adaptive and atmospheric optics, speckle techniques, and instrumentation. Particular papers are presented concerning recent progress on the IR Michelson array; the IOTA interferometer project; a space interferometer concept for the detection of extrasolar earth-like planets; IR speckle imaging at Palomar; optical diameters of stars measured with the Mt. Wilson Mark III interferometer; the IR array camera for interferometry with the cophased Multiple Mirror Telescope; optimization techniques appliesd to the bispectrum of one-dimensional IR astronomical speckle data; and adaptive optical iamging for extended objects.

Experimental implementation of phase locking in a nonlinear interferometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hailong; Jing, Jietai, E-mail: jtjing@phy.ecnu.edu.cn; Marino, A. M.

2015-09-21

Based upon two cascade four-wave mixing processes in two identical hot rubidium vapor cells, a nonlinear interferometer has been experimentally realized [Jing et al., Appl. Phys. Lett. 99, 011110 (2011); Hudelist et al., Nat. Commun. 5, 3049 (2014)]. It has a higher degree of phase sensitivity than a traditional linear interferometer and has many potential applications in quantum metrology. Phase locking of the nonlinear interferometer is needed before it can find its way into applications. In this letter, we investigate the experimental implementation of phase locking of the relative phase between the three beams at different frequencies involved in suchmore » a nonlinear interferometer. We have utilized two different methods, namely, beat note locking and coherent modulation locking. We find that coherent modulation locking can achieve much better phase stability than beat note locking in our system. Our results pave the way for real applications of a nonlinear interferometer in precision measurement and quantum manipulation, for example, phase control in phase-sensitive N-wave mixing process, N-port nonlinear interferometer and quantum-enhanced real-time phase tracking.« less

Pupil engineering for a confocal reflectance line-scanning microscope

NASA Astrophysics Data System (ADS)

Patel, Yogesh G.; Rajadhyaksha, Milind; DiMarzio, Charles A.

2011-03-01

Confocal reflectance microscopy may enable screening and diagnosis of skin cancers noninvasively and in real-time, as an adjunct to biopsy and pathology. Current confocal point-scanning systems are large, complex, and expensive. A confocal line-scanning microscope, utilizing a of linear array detector can be simpler, smaller, less expensive, and may accelerate the translation of confocal microscopy in clinical and surgical dermatology. A line scanner may be implemented with a divided-pupil, half used for transmission and half for detection, or with a full-pupil using a beamsplitter. The premise is that a confocal line-scanner with either a divided-pupil or a full-pupil will provide high resolution and optical sectioning that would be competitive to that of the standard confocal point-scanner. We have developed a confocal line-scanner that combines both divided-pupil and full-pupil configurations. This combined-pupil prototype is being evaluated to determine the advantages and limitations of each configuration for imaging skin, and comparison of performance to that of commercially available standard confocal point-scanning microscopes. With the combined configuration, experimental evaluation of line spread functions (LSFs), contrast, signal-to-noise ratio, and imaging performance is in progress under identical optical and skin conditions. Experimental comparisons between divided-pupil and full-pupil LSFs will be used to determine imaging performance. Both results will be compared to theoretical calculations using our previously reported Fourier analysis model and to the confocal point spread function (PSF). These results may lead to a simpler class of confocal reflectance scanning microscopes for clinical and surgical dermatology.

Cochlear implanted pupils in Scottish schools: 4-year school attainment data (2000-2004).

PubMed

Thoutenhoofd, Ernst

2006-01-01

The Achievements of Deaf Pupils in Scotland (ADPS) project has been tracking the educational attainment of deaf pupils in Scotland's schools since 2000. At the time of writing, the database contains records for 1,752 deaf pupils (2000-2005). Here 4-year aggregate educational attainment data are reported for a subset of 152 school-aged deaf pupils with cochlear implants notified to the ADPS database between June 2000 and June 2004. The data describe primary and secondary school results in reading, writing, and math for this subgroup, as well as placement and communication characteristics. The educational attainment of the group of deaf pupils with cochlear implants is clearly marked when the deaf pupil population is disaggregated for hearing loss, achieving comparatively higher average attainment in both 5-14 Curriculum National Tests (Mathematics in particular) and Standard Grades. Therefore the gap in performance relative to the national population data is reduced for those deaf pupils, although it still widens at higher levels of achievement for the National Tests. Although most pupils with cochlear implants are placed in the mainstream, there is no pattern of migration toward mainstream schools. Some deaf pupils with cochlear implants moved out of mainstream to other types of placement, and this has implications for health-economic cost-utility assessments of cochlear implantation that favor mainstream education by drawing upon the relative cost of different placement types. These findings suggest that the ADPS program of research can contribute school outcome data as valuable real-life outcome measures in wider assessments of the benefit of cochlear implants to deaf children and deaf young people.

Pupils' liking for school: ability grouping, self-concept and perceptions of teaching.

PubMed

Ireson, Judith; Hallam, Susan

2005-06-01

Research indicates that affective aspects of development provide a basis for autonomous learning. Pupils' liking for school may be a useful indicator of their relationships with teachers and the school. The aim of the research reported in this paper is to establish the properties of a measure of pupils' liking for school and to examine associations between this measure, pupils' experiences in lessons, their self-concepts and the amount of setting implemented in school. A stratified sample of 45 mixed secondary comprehensive schools was selected for the research. Schools represented a variety of ability-grouping practices in the lower school (Years 7-9), from completely mixed-ability to setting in all academic subjects. All Year 9 pupils were included in the sample. Pupils completed a questionnaire containing items on their self-concept, liking for school, and their perceptions of teaching in English, mathematics, and science. Data on pupils' gender, ethnic origin, social disadvantage and attainment was also collected. The properties and correlates of scales indicating pupils' liking for school and their perceptions of teaching in English, mathematics, and science are established. Liking for school is greater among girls, pupils with higher academic self-concepts, and those with more positive perceptions of teaching. Pupils are more positive about teaching they experience in English than in mathematics or science. When other variables are statistically controlled, there is no significant effect of the extent of ability grouping in the school as a whole. Affective aspects of learning should not be neglected in the drive to raise standards.

Promoting prosocial pupil behaviour: 2-secondary school intervention and pupil effects.

PubMed

Mooij, T

1999-12-01

In an earlier article (Mooij, 1999c) a theoretical multilevel model to promote prosocial pupil behaviour by stimulating specific educational conditions was developed. To carry out school interventions to check empirically whether pupil level effects occur because of educational changes at the classroom and school level. Seven secondary schools with relatively high degrees of pupil aggression were selected. Four schools took part as intervention schools, three schools served as control schools. In 1995 (pretest) and 1997 (post-test) pupils and form teachers of the first and third school years participated by completing questionnaires. Within the pupil cohorts, a longitudinal group of 352 pupils was included. Pretest questionnaires in 1995 were followed by intervention in the intervention schools. Teachers collaborated with staff and researchers to increase pupils' participation and responsibility in specifying and controlling behavioural and didactic rules, related to didactic differentiation during lessons. The validity of the intervention implementation was checked using qualitative information and quantitative data from both pre- and post-test. Longitudinal intervention effects were tested by applying two-level multiple regression analyses. After controlling for pretest and covariables in school year 1, school intervention effects were found in school year 3 with the prediction of being a perpetrator of aggressive behaviour at school, aggressive behaviour outside school, and criminal behaviour. Some small effects were found with respect to victim behaviour. Social-pedagogical and didactic class and school variables, but also home variables and support by peers without problematic behaviour, could be integrated more systematically to promote prosocial development of a pupil's behaviour from the beginning in school.

Image quality comparison of two multifocal IOLs: influence of the pupil.

PubMed

García-Domene, Mari Carmen; Felipe, Adelina; Peris-Martínez, Cristina; Navea, Amparo; Artigas, Jose M; Pons, Álvaro M

2015-04-01

To evaluate the effect of pupil size on image quality of a sectorial multifocal intraocular lens (IOL), the Lentis Mplus (Oculentis GmbH, Berlin, Germany), and the Acri.LISA IOL (Carl Zeiss Meditec, Jena, Germany). The authors measured the MTFs of the Lentis Mplus LS-312 IOL and the Acri.LISA 366D IOL with three different sizes of pupil diameters: 3, 4, and 5 mm. The MTF was calculated from the cross-line spread function recorded with the OPAL Vector System (Image Science Ltd., Oxford, UK) by using fast Fourier-transform techniques. In distance focus, the image quality provided by the Lentis Mplus IOL was better than that of the Acri. LISA IOL with all pupil diameters. In near focus, the MTF of the Acri.LISA IOL was better with a 3-mm pupil, but poor with larger pupils. The aberration effect was equal in both IOLs in distance focus, but in near focus and with a 3-mm pupil, the Acri.LISA IOL was less affected by the aberration than the Lentis Mplus IOL. The Lentis Mplus IOL provides better distance image quality than the Acri.LISA IOL, whereas the near image quality of the Acri.LISA IOL is better with small-pupil diameter. The sectorial design makes this IOL more suitable for patients with a pupil diameter greater than 3 mm. Copyright 2015, SLACK Incorporated.

Pupil dilation signals uncertainty and surprise in a learning gambling task.

PubMed

Lavín, Claudio; San Martín, René; Rosales Jubal, Eduardo

2013-01-01

Pupil dilation under constant illumination is a physiological marker where modulation is related to several cognitive functions involved in daily decision making. There is evidence for a role of pupil dilation change during decision-making tasks associated with uncertainty, reward-prediction errors and surprise. However, while some work suggests that pupil dilation is mainly modulated by reward predictions, others point out that this marker is related to uncertainty signaling and surprise. Supporting the latter hypothesis, the neural substrate of this marker is related to noradrenaline (NA) activity which has been also related to uncertainty signaling. In this work we aimed to test whether pupil dilation is a marker for uncertainty and surprise in a learning task. We recorded pupil dilation responses in 10 participants performing the Iowa Gambling Task (IGT), a decision-making task that requires learning and constant monitoring of outcomes' feedback, which are important variables within the traditional study of human decision making. Results showed that pupil dilation changes were modulated by learned uncertainty and surprise regardless of feedback magnitudes. Interestingly, greater pupil dilation changes were found during positive feedback (PF) presentation when there was lower uncertainty about a future negative feedback (NF); and by surprise during NF presentation. These results support the hypothesis that pupil dilation is a marker of learned uncertainty, and may be used as a marker of NA activity facing unfamiliar situations in humans.

Pupil dilation signals uncertainty and surprise in a learning gambling task

PubMed Central

Lavín, Claudio; San Martín, René; Rosales Jubal, Eduardo

2014-01-01

Pupil dilation under constant illumination is a physiological marker where modulation is related to several cognitive functions involved in daily decision making. There is evidence for a role of pupil dilation change during decision-making tasks associated with uncertainty, reward-prediction errors and surprise. However, while some work suggests that pupil dilation is mainly modulated by reward predictions, others point out that this marker is related to uncertainty signaling and surprise. Supporting the latter hypothesis, the neural substrate of this marker is related to noradrenaline (NA) activity which has been also related to uncertainty signaling. In this work we aimed to test whether pupil dilation is a marker for uncertainty and surprise in a learning task. We recorded pupil dilation responses in 10 participants performing the Iowa Gambling Task (IGT), a decision-making task that requires learning and constant monitoring of outcomes’ feedback, which are important variables within the traditional study of human decision making. Results showed that pupil dilation changes were modulated by learned uncertainty and surprise regardless of feedback magnitudes. Interestingly, greater pupil dilation changes were found during positive feedback (PF) presentation when there was lower uncertainty about a future negative feedback (NF); and by surprise during NF presentation. These results support the hypothesis that pupil dilation is a marker of learned uncertainty, and may be used as a marker of NA activity facing unfamiliar situations in humans. PMID:24427126

Raising Pupil Attainment through Family Learning: A Guide for Head Teachers and School Governors

ERIC Educational Resources Information Center

Learning and Work Institute, 2016

2016-01-01

This guide is for head teachers and school governors to help them invest their Pupil Premium funding in Family Learning programmes. The Pupil Premium is additional funding for schools in England to raise the attainment of disadvantaged pupils and close the gap between them and their peers. Family Learning is a pedagogical approach that refers to…

Primary School Pupils' Views of Characteristics of Good Primary School Teachers: An Exploratory, Open Approach for Investigating Pupils' Perceptions

ERIC Educational Resources Information Center

Bakx, Anouke; Koopman, Maaike; de Kruijf, Judith; den Brok, Perry

2015-01-01

This article reports on results of a study on pupils' perceptions on teacher quality in primary education. Pupils' perceptions of desired characteristics of good teachers in primary education were compared to results of research into teacher quality from different perspectives: (1) perception studies of ideal teaching-and-learning environments;…

The Relationship Between the Change in Pupil Control Ideology of Student Teachers and the Student Teachers's Perception of the Cooperating Teacher's Pupil Control Ideology.

ERIC Educational Resources Information Center

Roberts, Richard A.; Blankenship, Jacob W.

A sample of 108 elementary student teachers was administered the Pupil Control Ideology Form (PCI Form) before and after student teaching. The student teachers' perceptions of their cooperating teachers' pupil control ideology were measured using a modification of the same form. "Socialization pressure," the difference between the…

An Investigation into the Test Reliability of the Pupil Control Ideology Form.

ERIC Educational Resources Information Center

Gaffney, Patrick V.; Byrd-Gaffney, Sharon

The Pupil Control Ideology Form (PCI) is one of the major instruments used by researchers interested in the study of school climate. Pupil control is a central feature of the organizational life of schools, and each school appears to have a prevailing ideology of pupil control. The PCI is a self-report instrument used to measure an educator's…

Are Polish Primary School Pupils in Favor of Wearing Uniforms? Snapshot Comment

ERIC Educational Resources Information Center

Asotska, Julia; Butler, Norman L.; Davidson, Barry S.; Griffith, Kimberly Grantham; Brown, Veda E.; Kritsonis, Wiilliam Allan

2007-01-01

The purpose of this article is to discuss whether Polish primary school pupils want to wear uniforms, and it is motivated by the Polish government's recently proposed policy: Zero Tolerance for Violence at School. Seventy one pupils, who attend Podstawowka Nr30 school in Cracow, were surveyed, and the authors found that most pupils are not in…

Classroom Conditions for Effective Learning: Hearing the Voice of Key Stage 3 Pupils

ERIC Educational Resources Information Center

Hopkins, Elizabeth

2010-01-01

This article argues that accessing and taking note of the voice of pupils is critical in working towards removing barriers to effective learning. Pupil voice was accessed using an innovative form of group interview incorporating an Ishikawa or fishbone tool and card sorting exercise. The data were collected from 132 pupils, from Years 7 to 9 (aged…

Deaf Pupils' Reasoning about Scientific Phenomena: School Science as a Framework for Understanding or as Fragments of Factual Knowledge.

ERIC Educational Resources Information Center

Molander, B. O.; Pedersen, Svend; Norell, Kia

2001-01-01

A Swedish interview study of how deaf pupils reason about phenomena in a science context revealed significant variation in the extent to which pupils used scientific principles for reasoning about science phenomena, which suggests that for some pupils, school science offers little as a framework for reasoning. (Contains references.) (DB)

The Impact of School Culture on Schools' Pupil Well-Being Policy-Making Capacities

ERIC Educational Resources Information Center

Van Gasse, Roos; Vanhoof, Jan; Van Petegem, Peter

2016-01-01

Pupil well-being has been an important topic in educational research for some time. Differences between schools in their influence on the well-being of their pupils are attributed to the policy-making capacities of the school. Little is known about schools' policy-making capacities with regard to pupil well-being, and the impact of school culture…

"Just Google It?": Pupils' Perceptions and Experience of Research in the Secondary Classroom

ERIC Educational Resources Information Center

Yeoman, Kay; Nardi, Elena; Bowater, Laura; Nguyen, Huyen

2017-01-01

While numerous studies examine perceptions of research held by university researchers, studies examining perceptions held by school pupils are rare. To address this gap and following analysis of questionnaire data (N = 2634, KS3/4/5 pupils), we conducted 11 group interviews with 100 pupils in England to investigate their experiences of research…

34 CFR 222.35 - How does a local educational agency count the membership of its federally connected children?

Code of Federal Regulations, 2011 CFR

2011-07-01

... also be obtained from school records), including— (A) Name of pupil; (B) Date of birth of the pupil; and (C) Name of public school and grade of the pupil. (ii) Pupil residence and parent employment... tribal official has jurisdiction. (Approved by the Office of Management and Budget under control number...

34 CFR 222.35 - How does a local educational agency count the membership of its federally connected children?

Code of Federal Regulations, 2012 CFR

2012-07-01

... also be obtained from school records), including— (A) Name of pupil; (B) Date of birth of the pupil; and (C) Name of public school and grade of the pupil. (ii) Pupil residence and parent employment... tribal official has jurisdiction. (Approved by the Office of Management and Budget under control number...

34 CFR 222.35 - How does a local educational agency count the membership of its federally connected children?

Code of Federal Regulations, 2014 CFR

2014-07-01

... also be obtained from school records), including— (A) Name of pupil; (B) Date of birth of the pupil; and (C) Name of public school and grade of the pupil. (ii) Pupil residence and parent employment... tribal official has jurisdiction. (Approved by the Office of Management and Budget under control number...

34 CFR 222.35 - How does a local educational agency count the membership of its federally connected children?

Code of Federal Regulations, 2013 CFR

2013-07-01

... also be obtained from school records), including— (A) Name of pupil; (B) Date of birth of the pupil; and (C) Name of public school and grade of the pupil. (ii) Pupil residence and parent employment... tribal official has jurisdiction. (Approved by the Office of Management and Budget under control number...

34 CFR 222.35 - How does a local educational agency count the membership of its federally connected children?

Code of Federal Regulations, 2010 CFR

2010-07-01

... also be obtained from school records), including— (A) Name of pupil; (B) Date of birth of the pupil; and (C) Name of public school and grade of the pupil. (ii) Pupil residence and parent employment... tribal official has jurisdiction. (Approved by the Office of Management and Budget under control number...

Relationship of Pupils' Spatial Perception and Ability with Their Performance in Geography

ERIC Educational Resources Information Center

Likouri, Anna-Aikaterini; Klonari, Aikaterini; Flouris, George

2017-01-01

The aim of this study was to investigate the correlation between pupils' spatial perception and abilities and their performance in geography. The sample was 600 6th-grade pupils from various areas of Greece selected by the cluster sampling method. The study results showed that: a) the vast majority of pupils showed low spatial ability; b) there…

Turkish Pupils' Conceptions of the Particulate Nature of Matter

ERIC Educational Resources Information Center

Boz, Yezdan

2006-01-01

The purpose of this research study is to explore year 6, 8 & 11 (13, 15 and 17 years old respectively) Turkish pupils' views about the particulate nature of matter within the context of phase changes. About 300 pupils participated in the study. Questionnaires distributed to year 6, 8 and 11 pupils included 6-item open-ended questions about (a)…

Attitudes of Serbian and Slovenian Student Teachers towards Causes of Learning Underachievement amongst Roma Pupils

ERIC Educational Resources Information Center

Macura-Milovanovic, Suncica; Pecek, Mojca

2013-01-01

The task of initial teacher education is to prepare student teachers (ST) to accept responsibility for improving the education of all pupils, including Roma pupils. Thus, knowledge of ST's attitudes regarding such pupils at the onset of initial teacher education is a key for the creation of teacher education programmes that challenge implicit…

Task difficulty differentially affects two measures of processing load: the pupil response during sentence processing and delayed cued recall of the sentences.

PubMed

Zekveld, Adriana A; Festen, Joost M; Kramer, Sophia E

2013-08-01

In this study, the authors assessed the influence of masking level (29% or 71% sentence perception) and test modality on the processing load during language perception as reflected by the pupil response. In addition, the authors administered a delayed cued stimulus recall test to examine whether processing load affected the encoding of the stimuli in memory. Participants performed speech and text reception threshold tests, during which the pupil response was measured. In the cued recall test, the first half of correctly perceived sentences was presented, and participants were asked to complete the sentences. Reading and listening span tests of working memory capacity were presented as well. Regardless of test modality, the pupil response indicated higher processing load in the 29% condition than in the 71% correct condition. Cued recall was better for the 29% condition. The consistent effect of masking level on the pupil response during listening and reading support the validity of the pupil response as a measure of processing load during language perception. The absent relation between pupil response and cued recall may suggest that cued recall is not directly related to processing load, as reflected by the pupil response.

Training teachers in generalized writing of behavior modification programs for multihandicapped deaf children.

PubMed

Hundert, J

1982-01-01

In contrast to previous studies where teachers were instructed how to implement behavior modification programs designed by an experimenter, teachers in the present experiment were taught how to write as well as implement behavior modification programs. The generalized effects of two training conditions on teacher and pupil behaviors were assessed by a multiple baseline design where, following baseline, two teachers of multi-handicapped deaf children were taught to set objectives and measure pupil performance (measurement training), Later, through a training manual, they learned a general problem-solving approach to writing behavior modification programs (programming training). After both training conditions, experimenter feedback was given for teachers' application of training to a target behavior for one pupil and generalization was measured across target behaviors for the same pupil and across pupils. It was found that measurement training had little general effect on either teacher behavior or pupil behavior. However, after programming training, teachers increased their program writing and correct use of behavior modification procedures and generalized this training across pupils and target behaviors. Along with these effects, there was improvement in pupil behaviors. Possible explanation for generalized effects of teacher training were considered.

Pupil old/new effects reflect stimulus encoding and decoding in short-term memory.

PubMed

Brocher, Andreas; Graf, Tim

2016-12-01

We conducted five pupil old/new experiments to examine whether pupil old/new effects can be linked to familiarity and/or recollection processes of recognition memory. In Experiments 1-3, we elicited robust pupil old/new effects for legal words and pseudowords (Experiment 1), positive and negative words (Experiment 2), and low-frequency and high-frequency words (Experiment 3). Importantly, unlike for old/new effects in ERPs, we failed to find any effects of long-term memory representations on pupil old/new effects. In Experiment 4, using the words and pseudowords from Experiment 1, participants made lexical decisions instead of old/new decisions. Pupil old/new effects were restricted to legal words. Additionally requiring participants to make speeded responses (Experiment 5) led to a complete absence of old/new effects. Taken together, these data suggest that pupil old/new effects do not map onto familiarity and recollection processes of recognition memory. They rather seem to reflect strength of memory traces in short-term memory, with little influence of long-term memory representations. Crucially, weakening the memory trace through manipulations in the experimental task significantly reduces pupil/old new effects. © 2016 Society for Psychophysiological Research.

Inquiry-based science education: scaffolding pupils' self-directed learning in open inquiry

NASA Astrophysics Data System (ADS)

van Uum, Martina S. J.; Verhoeff, Roald P.; Peeters, Marieke

2017-12-01

This paper describes a multiple case study on open inquiry-based learning in primary schools. During open inquiry, teachers often experience difficulties in balancing support and transferring responsibility to pupils' own learning. To facilitate teachers in guiding open inquiry, we developed hard and soft scaffolds. The hard scaffolds consisted of documents with explanations and/or exercises regarding difficult parts of the inquiry process. The soft scaffolds included explicit references to and additional explanations of the hard scaffolds. We investigated how teacher implementation of these scaffolds contributed to pupils' self-directed learning during open inquiry. Four classes of pupils, aged 10-11, were observed while they conducted an inquiry lesson module of about 10 lessons in their classrooms. Data were acquired via classroom observations, audio recordings, and interviews with teachers and pupils. The results show that after the introduction of the hard scaffolds by the teacher, pupils were able and willing to apply them to their investigations. Combining hard scaffolds with additional soft scaffolding promoted pupils' scientific understanding and contributed to a shared guidance of the inquiry process by the teacher and her pupils. Our results imply that the effective use of scaffolds is an important element to be included in teacher professionalisation.

Factors associated with pupil toilet use in kenyan primary schools.

PubMed

Garn, Joshua V; Caruso, Bethany A; Drews-Botsch, Carolyn D; Kramer, Michael R; Brumback, Babette A; Rheingans, Richard D; Freeman, Matthew C

2014-09-17

The purpose of this study was to quantify how school sanitation conditions are associated with pupils' use of sanitation facilities. We conducted a longitudinal assessment in 60 primary schools in Nyanza Province, Kenya, using structured observations to measure facility conditions and pupils' use at specific facilities. We used multivariable mixed regression models to characterize how pupil to toilet ratio was associated with toilet use at the school-level and also how facility conditions were associated with pupils' use at specific facilities. We found a piecewise linear relationship between decreasing pupil to toilet ratio and increasing pupil toilet use (p < 0.01). Our data also revealed significant associations between toilet use and newer facility age (p < 0.01), facility type (p < 0.01), and the number of toilets in a facility (p < 0.01). We found some evidence suggesting facility dirtiness may deter girls from use (p = 0.06), but not boys (p = 0.98). Our study is the first to rigorously quantify many of these relationships, and provides insight into the complexity of factors affecting pupil toilet use patterns, potentially leading to a better allocation of resources for school sanitation, and to improved health and educational outcomes for children.

Corneal aberrations in keratoconic eyes: influence of pupil size and centering

NASA Astrophysics Data System (ADS)

Comastri, S. A.; Perez, L. I.; Pérez, G. D.; Martin, G.; Bianchetti, A.

2011-01-01

Ocular aberrations vary among subjects and under different conditions and are commonly analyzed expanding the wavefront aberration function in Zernike polynomials. In previous articles, explicit analytical formulas to transform Zernike coefficients of up to 7th order corresponding to an original pupil into those related to a contracted displaced new pupil are obtained. In the present paper these formulas are applied to 20 keratoconic corneas of varying severity. Employing the SN CT1000 topographer, aberrations of the anterior corneal surface for a pupil of semi-diameter 3 mm centered on the keratometric axis are evaluated, the relation between the higher-order root mean square wavefront error and the index KISA% characterizing keratoconus is studied and the size and centering of the ocular photopic natural pupil are determined. Using these data and the transformation formulas, new coefficients associated to the photopic pupil size are computed and their variation when coordinates origin is shifted from the keratometric axis to the ocular pupil centre is analyzed.

Effects of Photo-Depicted Pupil Diameter on Judgments of Others' Attentiveness and on Facial Recognition Memory.

PubMed

Watier, Nicholas; Healy, Christopher; Armstrong, Heather

2017-04-01

Occasionally, individuals perceive that someone is no longer paying attention to the discussion at hand even when there are no overt cues of inattentiveness. As a preliminary study of this phenomenon, we examined whether pupil diameter might be implicitly used to infer others' attentiveness. Forty participants (27 women, 13 men, M age = 19.7 year, SD = 2.8) were presented with images of male faces with either large or small pupils, and, in the context of a personnel selection scenario, participants then judged the attentiveness of the person in the image. Images of faces with large pupils were judged as more attentive, compared with images of faces with small pupils. Face recognition memory performance was not affected by depicted pupil size. Our results are consistent with the proposal that pupillary fluctuations can be an index of perceived attention, and they provide preliminary evidence that pupil dilation may be implicitly relied upon to infer attentional states.

Contact-free trans-pars-planar illumination enables snapshot fundus camera for nonmydriatic wide field photography.

PubMed

Wang, Benquan; Toslak, Devrim; Alam, Minhaj Nur; Chan, R V Paul; Yao, Xincheng

2018-06-08

In conventional fundus photography, trans-pupillary illumination delivers illuminating light to the interior of the eye through the peripheral area of the pupil, and only the central part of the pupil can be used for collecting imaging light. Therefore, the field of view of conventional fundus cameras is limited, and pupil dilation is required for evaluating the retinal periphery which is frequently affected by diabetic retinopathy (DR), retinopathy of prematurity (ROP), and other chorioretinal conditions. We report here a nonmydriatic wide field fundus camera employing trans-pars-planar illumination which delivers illuminating light through the pars plana, an area outside of the pupil. Trans-pars-planar illumination frees the entire pupil for imaging purpose only, and thus wide field fundus photography can be readily achieved with less pupil dilation. For proof-of-concept testing, using all off-the-shelf components a prototype instrument that can achieve 90° fundus view coverage in single-shot fundus images, without the need of pharmacologic pupil dilation was demonstrated.

Removal of central obscuration and spiders for coronagraphy

NASA Astrophysics Data System (ADS)

Abe, L.; Nishikawa, J.; Murakami, N.; Tamura, M.

2006-06-01

We present a method to remove the central obscuration and spiders, or any kind of geometry inside a telescope pupil. The technique relies on the combination of a first focal plane diffracting mask, and a complex amplitude pupil mask. In this combination, the central obscuration and eventual spider arms patterns in the re-imaged pupil (after the diffracting mask) are filled with coherent light. Adding an appropriate complex amplitude pupil mask allows virtually any kind of pupil shaping (in both amplitude and/or phase). We show that the obtained output pupil can feed a high efficiency coronagraph (any kind) with a very reasonable overall throughput and good performance even when considering pointing errors. In this paper, we specifically assess the performance of this technique when using apodized entrance pupils. This technique is relevant for ground based telescopes foreseeing the advent of higher order (so called ExAO) adaptive optics systems providing very high Strehl ratios. Some feasibility points are also discussed. adaptive optics systems providing very high Strehl ratios. Some feasibility points are also discussed.

Measurement of Postmortem Pupil Size: A New Method with Excellent Reliability and Its Application to Pupil Changes in the Early Postmortem Period.

PubMed

Fleischer, Luise; Sehner, Susanne; Gehl, Axel; Riemer, Martin; Raupach, Tobias; Anders, Sven

2017-05-01

Measurement of postmortem pupil width is a potential component of death time estimation. However, no standardized measurement method has been described. We analyzed a total of 71 digital images for pupil-iris ratio using the software ImageJ. Images were analyzed three times by four different examiners. In addition, serial images from 10 cases were taken between 2 and 50 h postmortem to detect spontaneous pupil changes. Intra- and inter-rater reliability of the method was excellent (ICC > 0.95). The method is observer independent and yields consistent results, and images can be digitally stored and re-evaluated. The method seems highly eligible for forensic and scientific purposes. While statistical analysis of spontaneous pupil changes revealed a significant polynomial of quartic degree for postmortem time (p = 0.001), an obvious pattern was not detected. These results do not indicate suitability of spontaneous pupil changes for forensic death time estimation, as formerly suggested. © 2016 American Academy of Forensic Sciences.

Pupil Size Tracks Attentional Performance In Attention-Deficit/Hyperactivity Disorder.

PubMed

Wainstein, G; Rojas-Líbano, D; Crossley, N A; Carrasco, X; Aboitiz, F; Ossandón, T

2017-08-15

Attention-deficit/hyperactivity disorder (ADHD) diagnosis is based on reported symptoms, which carries the potential risk of over- or under-diagnosis. A biological marker that helps to objectively define the disorder, providing information about its pathophysiology, is needed. A promising marker of cognitive states in humans is pupil size, which reflects the activity of an 'arousal' network, related to the norepinephrine system. We monitored pupil size from ADHD and control subjects, during a visuo-spatial working memory task. A sub group of ADHD children performed the task twice, with and without methylphenidate, a norepinephrine-dopamine reuptake inhibitor. Off-medication patients showed a decreased pupil diameter during the task. This difference was no longer present when patients were on-medication. Pupil size correlated with the subjects' performance and reaction time variability, two vastly studied indicators of attention. Furthermore, this effect was modulated by medication. Through pupil size, we provide evidence of an involvement of the noradrenergic system during an attentional task. Our results suggest that pupil size could serve as a biomarker in ADHD.

Association of pupil vandalism, bullying and truancy with teachers' absence due to illness: a multilevel analysis.

PubMed

Ervasti, Jenni; Kivimäki, Mika; Puusniekka, Riikka; Luopa, Pauliina; Pentti, Jaana; Suominen, Sakari; Vahtera, Jussi; Virtanen, Marianna

2012-06-01

The aim of this study was to examine whether vandalism, bullying, and truancy among pupils at school are associated with absence due to illness among teachers. Data on such problem behaviour of 17,033 pupils in 90 schools were linked to absence records of 2364 teachers. Pupil reported vandalism and bullying at the school-level were associated with teachers' short-term (1- to 3-day) absences. Cumulative exposure to various forms of pupils' problem behaviour was associated with even higher rates of short-term absences among teachers. No association was found between pupils' problem behaviour and teachers' long-term (>3-day) absences. In conclusion, there seems to be a link between pupils' problem behaviour and teachers' short-term absence due to illness. Further work should determine whether problem behaviour is a cause or a consequence of absences or whether the association is noncausal. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Pupil size changes during recognition memory.

PubMed

Otero, Samantha C; Weekes, Brendan S; Hutton, Samuel B

2011-10-01

Pupils dilate to a greater extent when participants view old compared to new items during recognition memory tests. We report three experiments investigating the cognitive processes associated with this pupil old/new effect. Using a remember/know procedure, we found that the effect occurred for old items that were both remembered and known at recognition, although it was attenuated for known compared to remembered items. In Experiment 2, the pupil old/new effect was observed when items were presented acoustically, suggesting the effect does not depend on low-level visual processes. The pupil old/new effect was also greater for items encoded under deep compared to shallow orienting instructions, suggesting it may reflect the strength of the underlying memory trace. Finally, the pupil old/new effect was also found when participants falsely recognized items as being old. We propose that pupils respond to a strength-of-memory signal and suggest that pupillometry provides a useful technique for exploring the underlying mechanisms of recognition memory. Copyright © 2011 Society for Psychophysiological Research.

Dataset of red light induced pupil constriction superimposed on post-illumination pupil response.

PubMed

Lei, Shaobo; Goltz, Herbert C; Sklar, Jaime C; Wong, Agnes M F

2016-09-01

We collected and analyzed pupil diameter data from of 7 visually normal participants to compare the maximum pupil constriction (MPC) induced by "Red Only" vs. "Blue+Red" visual stimulation conditions. The "Red Only" condition consisted of red light (640±10 nm) stimuli of variable intensity and duration presented to dark-adapted eyes with pupils at resting state. This condition stimulates the cone-driven activity of the intrinsically photosensitive retinal ganglion cells (ipRGC). The "Blue+Red" condition consisted of the same red light stimulus presented during ongoing blue (470±17 nm) light-induced post-illumination pupil response (PIPR), representing the cone-driven ipRGC activity superimposed on the melanopsin-driven intrinsic activity of the ipRGCs ("The Absence of Attenuating Effect of Red light Exposure on Pre-existing Melanopsin-Driven Post-illumination Pupil Response" Lei et al. (2016) [1]). MPC induced by the "Red Only" condition was compared with the MPC induced by the "Blue+Red" condition by multiple paired sample t -tests with Bonferroni correction.

Benefits of Model Updating: A Case Study Using the Micro-Precision Interferometer Testbed

NASA Technical Reports Server (NTRS)

Neat, Gregory W.; Kissil, Andrew; Joshi, Sanjay S.

1997-01-01

This paper presents a case study on the benefits of model updating using the Micro-Precision Interferometer (MPI) testbed, a full-scale model of a future spaceborne optical interferometer located at JPL.

Terrestrial Planet Finder Interferometer: 2007-2008 Progress and Plans

NASA Technical Reports Server (NTRS)

Lawson, P. R.; Lay, O. P.; Martin, S. R.; Peters, R. D.; Gappinger, R. O.; Ksendzov, A.; Scharf, D. P.; Booth, A. J.; Beichman, C. A.; Serabyn, E.;

Construction of a Fiber Optic Gradient Hydrophone Using a Michelson Configuration.

DTIC Science & Technology

1986-03-27

Michelson interferometers; * Fabry - Perot interferometers; • Intermode interferometers; • Sagnac interferometers. Of these, the first two categories show the...most promise for hydrophone applications. The Fabry - Perot design is an excellent tool for precision length measurements but is extremely sensitive to...Pa was measured. Using the demodulation technique in Mills, [Ref. 13: pp. 94-95], one can make a comparison to the USRD type G63 stan- dard pressure

Collisional Decoherence in Trapped-Atom Interferometers that use Nondegenerate Sources

DTIC Science & Technology

2009-01-22

a magneto - optical trap . The trap is switched off and the atomic cloud begins to fall due to gravity. At the time t=0, the cloud is illuminated with...model is used to find the optimal operating conditions of the interferometer and direct Monte-Carlo simulation of the interferometer is used to...A major difficulty with all trapped -atom interferometers that use optical pulses is that the residual potential along the guide causes

Solar Confocal Interferometers for Sub-Picometer-Resolution Spectral Filters

NASA Technical Reports Server (NTRS)

Gary, G. Allen; Pietraszewski, Chris; West, Edward A.; Dines, Terence C.

2006-01-01

The confocal Fabry-Perot interferometer allows sub-picometer spectral resolution of Fraunhofer line profiles. Such high spectral resolution is needed to keep pace with the higher spatial resolution of the new set of large-aperture solar telescopes. The line-of-sight spatial resolution derived for line profile inversions would then track the improvements of the transverse spatial scale provided by the larger apertures. The confocal interferometer's unique properties allow a simultaneous increase in both etendue and spectral power. Methods: We have constructed and tested two confocal interferometers. Conclusions: In this paper we compare the confocal interferometer with other spectral imaging filters, provide initial design parameters, show construction details for two designs, and report on the laboratory test results for these interferometers, and propose a multiple etalon system for future testing of these units and to obtain sub-picometer spectral resolution information on the photosphere in both the visible and near-infrared.

Very high-resolution spectroscopy for extremely large telescopes using pupil slicing and adaptive optics.

PubMed

Beckers, Jacques M; Andersen, Torben E; Owner-Petersen, Mette

2007-03-05

Under seeing limited conditions very high resolution spectroscopy becomes very difficult for extremely large telescopes (ELTs). Using adaptive optics (AO) the stellar image size decreases proportional with the telescope diameter. This makes the spectrograph optics and hence its resolution independent of the telescope diameter. However AO for use with ELTs at visible wavelengths require deformable mirrors with many elements. Those are not likely to be available for quite some time. We propose to use the pupil slicing technique to create a number of sub-pupils each of which having its own deformable mirror. The images from all sub-pupils are combined incoherently with a diameter corresponding to the diffraction limit of the sub-pupil. The technique is referred to as "Pupil Slicing Adaptive Optics" or PSAO.

ON THE DETECTION OF GLOBAL 21-cm SIGNAL FROM REIONIZATION USING INTERFEROMETERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singh, Saurabh; Subrahmanyan, Ravi; Shankar, N. Udaya

2015-12-20

Detection of the global redshifted 21-cm signal is an excellent means of deciphering the physical processes during the Dark Ages and subsequent Epoch of Reionization (EoR). However, detection of this faint monopole is challenging due to the high precision required in instrumental calibration and modeling of substantially brighter foregrounds and instrumental systematics. In particular, modeling of receiver noise with mK accuracy and its separation remains a formidable task in experiments aiming to detect the global signal using single-element spectral radiometers. Interferometers do not respond to receiver noise; therefore, here we explore the theory of the response of interferometers to globalmore » signals. In other words, we discuss the spatial coherence in the electric field arising from the monopole component of the 21-cm signal and methods for its detection using sensor arrays. We proceed by first deriving the response to uniform sky of two-element interferometers made of unit dipole and resonant loop antennas, then extend the analysis to interferometers made of one-dimensional arrays and also consider two-dimensional aperture antennas. Finally, we describe methods by which the coherence might be enhanced so that the interferometer measurements yield improved sensitivity to the monopole component. We conclude (a) that it is indeed possible to measure the global 21-cm from EoR using interferometers, (b) that a practically useful configuration is with omnidirectional antennas as interferometer elements, and (c) that the spatial coherence may be enhanced using, for example, a space beam splitter between the interferometer elements.« less

A heterodyne straightness and displacement measuring interferometer with laser beam drift compensation for long-travel linear stage metrology.

PubMed

Chen, Benyong; Cheng, Liang; Yan, Liping; Zhang, Enzheng; Lou, Yingtian

2017-03-01

The laser beam drift seriously influences the accuracy of straightness or displacement measurement in laser interferometers, especially for the long travel measurement. To solve this problem, a heterodyne straightness and displacement measuring interferometer with laser beam drift compensation is proposed. In this interferometer, the simultaneous measurement of straightness error and displacement is realized by using heterodyne interferometry, and the laser beam drift is determined to compensate the measurement results of straightness error and displacement in real time. The optical configuration of the interferometer is designed. The principle of the simultaneous measurement of straightness, displacement, and laser beam drift is depicted and analyzed in detail. And the compensation of the laser beam drift for the straightness error and displacement is presented. Several experiments were performed to verify the feasibility of the interferometer and the effectiveness of the laser beam drift compensation. The experiments of laser beam stability show that the position stability of the laser beam spot can be improved by more than 50% after compensation. The measurement and compensation experiments of straightness error and displacement by testing a linear stage at different distances show that the straightness and displacement obtained from the interferometer are in agreement with those obtained from a compared interferometer and the measured stage. These demonstrate that the merits of this interferometer are not only eliminating the influence of laser beam drift on the measurement accuracy but also having the abilities of simultaneous measurement of straightness error and displacement as well as being suitable for long-travel linear stage metrology.

(Re)Mapping the Colonized Body: The Creative Interventions of Rebecca Belmore in the Cityscape

ERIC Educational Resources Information Center

Nagam, Julie

2011-01-01

The cityscape holds the memories of indigenous bones and bodies that resurrect a deep sense of place that exists in the landscape of the city of Toronto. This deep sense of place is part of a connection to the land and stories of place. In this article, the author bridges the creative work of Anishinaabe artist Rebecca Belmore with the living…

Remapping the "Landscape of Choice": Patterns of Social Class Convergence in the Psycho-Social Factors Shaping the Higher Education Choice Process

ERIC Educational Resources Information Center

Kettley, Nigel Charles; Whitehead, Joan M.

2012-01-01

This paper provides a critique of recent Bourdieusian research into the higher education (HE) choice process. Specifically, Ball et al. (2002) maintain that class-related differences in students' psycho-social dispositions in Years 12 and 13, the "landscape of choice", shape their intentions or "decisions" to participate in HE and their selection…

High angular resolution and position determinations by infrared interferometry

NASA Technical Reports Server (NTRS)

1974-01-01

Interferometer systems are described in the form of publications and reports. 'Distance Meter Helps Track the Stars', 'Berkeley Heterodyne Interferometer', 'Infrared Heterodyne Spectroscopy of CO2 on Mars', and 'A 10 micron Heterodyne Stellar Interferometer' are papers reported.

High School Pupils' Understanding of Peer Counselling and Willingness to Use it for Different Types of Bullying

ERIC Educational Resources Information Center

Boulton, Michael John

2014-01-01

Bullying affects a substantial proportion of school pupils, and peer counselling services have been established to help tackle this problem. The present study aimed to further the understanding of why affected pupils do or do not choose to utilise this form of social support. Pupils ("N" = 99, aged 12-16 years) from the UK were asked…

Pedagogical Function of the Teacher Working in with Gifted Pupils

ERIC Educational Resources Information Center

Ceka, Ardita; Bajrami, Teuta Jusufi; Kadriu, Lulzime Lutfiu

2017-01-01

Working with gifted pupils is a specific problem which differs from the work with other pupils. It wouldn't be correct if we say that working with talented pupils is the same with the general pedagogical work. Even though we accept the gifted students as a particular problem, it is not right to see them as a world in its own, divided from other…

Parental Involvement as a Correlate of Academic Achievement of Primary School Pupils in Edo State, Nigeria

ERIC Educational Resources Information Center

Fajoju, Samuel A.; Aluede, Oyaziwo; Ojugo, Augustine I.

2016-01-01

This study investigated the relationship between parental involvement in children's education and the academic achievement of primary six pupils in Edo State, Nigeria. The ex-post facto research design was employed in this study. The sample consisted of 1,895 primary six pupils (1,024 males and 863 females drawn from 37,908 primary six pupils in…

Effects of a Six-Session Introductory Psychology Programme on Year 9 Pupils' Interest in Psychology and Approaches to Learning

ERIC Educational Resources Information Center

Norris, Emma; Chaves, Tahirah De Aguiar; Dunsmuir, Sandra

2015-01-01

Psychology is a popular UK A-level, despite many pupils having no previous taught experience of it. Prior introduction to psychology teaching could help pupils make more informed choices to study it. This study evaluates a six-session introduction to psychology programme for 20 Year 9 pupils called "Myth-Busting the Brain." A…

A Case Study on Pupils' Perceptions of Attending a Choral Class: You Get to Know One Another and Reach a Community

ERIC Educational Resources Information Center

Ehrlin, Anna

2016-01-01

Music activities can have a positive impact on pupils' schooling. It is therefore interesting to obtain more knowledge about pupils' perceptions of different kinds of music activities in school and how these activities affect their schooling. The study was conducted in Sweden at a municipal elementary school where pupils are offered choral lessons…

Pupil Home Background Characteristics and Academic Performance in Senior Secondary Schools: A Case Study of Selected Secondary Schools in Kitwe District, Zambia

ERIC Educational Resources Information Center

Kakumbi, Zonic; Samuel, Elizabeth B.; Mulendema, Peter J.

2016-01-01

The purpose of this research was to investigate pupil background characteristics and academic performance in senior secondary schools in Kitwe district with a view of recommending on how to improve pupils' performance. The study was conducted in Kitwe district because in the past years pupils' performance in senior secondary schools has been…

The Leading Group Effect: Illusionary Declines in Scholastic Standard Scores of Mid-Range Japanese Junior High School Pupils

ERIC Educational Resources Information Center

Mori, Kazuo; Uchida, Akitoshi

2012-01-01

Longitudinal change in the average Z scores for four groups of pupils sorted by quartiles was examined for its stability over three years. The data, collected from 1998 to 2009, was obtained from nine cohorts of Japanese junior high school pupils totaling 1,962 subjects. It showed illusionary declines among the mid-range pupils but improvements…

Missing Talent. Research Brief. Edition 5

ERIC Educational Resources Information Center

Allen, Rebecca

2015-01-01

Every year there are high achievers at primary school, pupils scoring in the top 10% nationally in their Key Stage 2 (KS2) tests, yet who five years later receive a set of GCSE results that place them outside the top 25% of pupils. There are about 7,000 such pupils each year, 15% of all those we term as highly able. We call these pupils our…

Teacher Verbal Feedback Directed towards Secondary Pupils with Challenging Behaviour and Its Relationship to Their Behaviour

ERIC Educational Resources Information Center

Swinson, J.; Knight, R.

2007-01-01

There is a body of evidence that has linked teachers' verbal feedback to pupils with pupil behaviour. In this study teacher verbal behaviour that was directed towards those pupils that the teachers had nominated as being especially difficult to teach was examined. A series of lessons was observed in a secondary school. The quality and quantity of…

Using Pupil Perspective Research to Inform Teacher Pedagogy: What Caribbean Pupils with Dyslexia Say about Teaching and Learning

ERIC Educational Resources Information Center

Blackman, Stacey

2011-01-01

The transformative potential of pupils' voices is well documented in past research by Pedder and McIntyre; and Cooper and McIntyre. In this qualitative research, I utilise a social constructivist framework by Vygotsky to ask pupils with dyslexia about the kinds of teacher strategies that they find helpful to their learning at secondary school in…

A Comparison of Written Compositions of Head-Start Pupils with Non-Head-Start Pupils.

ERIC Educational Resources Information Center

Houston, David Ree

This study--a follow-up to one conducted by Giles in 1965-- compared the written compositions of fourth grade pupils who had been in Project Head Start in the summer of 1965 with those of comparable pupils not in the program to determine possible differences in their written language development. Seventy Negro students were divided by sex and…

Naturally stable Sagnac–Michelson nonlinear interferometer

DOE PAGES

Lukens, Joseph M.; Peters, Nicholas A.; Pooser, Raphael C.

2016-11-16

Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. As a result, our configuration utilizes fewer components than previous demonstrations and requires nomore » active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.« less

FIBER AND INTEGRATED OPTICS. OTHER TOPICS IN QUANTUM ELECTRONICS: Fiber-optic interferometers: control of spectral composition of the radiation and formation of high-intensity optical pulses

NASA Astrophysics Data System (ADS)

Bulushev, A. G.; Dianov, Evgenii M.; Kuznetsov, A. V.; Okhotnikov, O. G.; Paramonov, Vladimir M.; Tsarev, Vladimir A.

1990-05-01

A study was made of the use of single-mode fiber ring interferometers in narrowing the emission lines of semiconductor lasers and increasing the optical radiation power. Efficient coupling of radiation, emitted by a multifrequency injection laser with an external resonator, into a fiber ring interferometer was achieved both under cw and mode-locking conditions. Matching of the optical lengths of the external resonator and the fiber interferometer made it possible to determine the mode width for this laser. A method for generation of optical pulses in a fiber ring interferometer from cw frequency modulated radiation was developed.

Oral health status of handicapped primary school pupils in Dar es Salaam, Tanzania.

PubMed

Simon, E N M; Matee, M I; Scheutz, F

2008-03-01

There is hardly any information regarding oral health status of handicapped primary school pupils in Tanzania. Determination of their oral health status could help in planning sustainable intervention programmes for this disadvantaged group. To determine caries and periodontal status and treatment needs of handicapped primary school pupils in Dar es Salaam, Tanzania. A descriptive cross-sectional study. Uhuru Mchanganyiko and Buguruni special schools, Dar es Salaam. The sample consisted of 179 (55.8%) males and 142 (44.2%) females aged between 7 and 22 years. Majority (71%) were deaf followed by blind (17.8%) and mentally retarded (8.7%). Six (1.9%) pupils were both deaf and blind, while one (0.3%) pupil was blind and mentally retarded. Forty one (12.8%) pupils had at least one decayed deciduous tooth, with the mean (dmfs) ranging from 0.25 to 3.24. The deaf had the highest mean decayed surfaces, followed by the mentally retarded and the blind. There was only one (0.3%) pupil who had a filled deciduous tooth. Thirty three (10.3%) pupils had decayed permanent teeth and 31 (9.7%) had missing permanent teeth. None of the decayed permanent teeth were restored. The blind had the lowest mean deciduous surfaces (DS) scores of between 0 and 1.0. In the mentally retarded group the mean DS ranged from 0.25 to 1.75. About 73.5% of the studied group had bleeding of the gums, with the blind having the highest mean bleeding index scores (p < 0.001) and about 82.8% of the pupils had calculus, with highest mean scores mainly among the blind (p = 0.008). The caries prevalence among handicapped primary school pupils was quite low. However, there was relatively high level of gingival bleeding and calculus. Regarding treatment needs, 23% required dental fillings mainly of one and two surface restorations and 82% required scaling and polishing. Despite these treatment needs these pupils had not received any dental attention.

Impact of Primary Spherical Aberration, Spatial Frequency and Stiles Crawford Apodization on Wavefront determined Refractive Error: A Computational Study

PubMed Central

Xu, Renfeng; Bradley, Arthur; Thibos, Larry N.

2013-01-01

Purpose We tested the hypothesis that pupil apodization is the basis for central pupil bias of spherical refractions in eyes with spherical aberration. Methods We employed Fourier computational optics in which we vary spherical aberration levels, pupil size, and pupil apodization (Stiles Crawford Effect) within the pupil function, from which point spread functions and optical transfer functions were computed. Through-focus analysis determined the refractive correction that optimized retinal image quality. Results For a large pupil (7 mm), as spherical aberration levels increase, refractions that optimize the visual Strehl ratio mirror refractions that maximize high spatial frequency modulation in the image and both focus a near paraxial region of the pupil. These refractions are not affected by Stiles Crawford Effect apodization. Refractions that optimize low spatial frequency modulation come close to minimizing wavefront RMS, and vary with level of spherical aberration and Stiles Crawford Effect. In the presence of significant levels of spherical aberration (e.g. C40 = 0.4 µm, 7mm pupil), low spatial frequency refractions can induce −0.7D myopic shift compared to high SF refraction, and refractions that maximize image contrast of a 3 cycle per degree square-wave grating can cause −0.75D myopic drift relative to refractions that maximize image sharpness. Discussion Because of small depth of focus associated with high spatial frequency stimuli, the large change in dioptric power across the pupil caused by spherical aberration limits the effective aperture contributing to the image of high spatial frequencies. Thus, when imaging high spatial frequencies, spherical aberration effectively induces an annular aperture defining that portion of the pupil contributing to a well-focused image. As spherical focus is manipulated during the refraction procedure, the dimensions of the annular aperture change. Image quality is maximized when the inner radius of the induced annulus falls to zero, thus defining a circular near paraxial region of the pupil that determines refraction outcome. PMID:23683093

Impact of contact lens zone geometry and ocular optics on bifocal retinal image quality

PubMed Central

Bradley, Arthur; Nam, Jayoung; Xu, Renfeng; Harman, Leslie; Thibos, Larry

2014-01-01

Purpose To examine the separate and combined influences of zone geometry, pupil size, diffraction, apodisation and spherical aberration on the optical performance of concentric zonal bifocals. Methods Zonal bifocal pupil functions representing eye + ophthalmic correction were defined by interleaving wavefronts from separate optical zones of the bifocal. A two-zone design (a central circular inner zone surrounded by an annular outer-zone which is bounded by the pupil) and a five-zone design (a central small circular zone surrounded by four concentric annuli) were configured with programmable zone geometry, wavefront phase and pupil transmission characteristics. Using computational methods, we examined the effects of diffraction, Stiles Crawford apodisation, pupil size and spherical aberration on optical transfer functions for different target distances. Results Apodisation alters the relative weighting of each zone, and thus the balance of near and distance optical quality. When spherical aberration is included, the effective distance correction, add power and image quality depend on zone-geometry and Stiles Crawford Effect apodisation. When the outer zone width is narrow, diffraction limits the available image contrast when focused, but as pupil dilates and outer zone width increases, aberrations will limit the best achievable image quality. With two-zone designs, balancing near and distance image quality is not achieved with equal area inner and outer zones. With significant levels of spherical aberration, multi-zone designs effectively become multifocals. Conclusion Wave optics and pupil varying ocular optics significantly affect the imaging capabilities of different optical zones of concentric bifocals. With two-zone bifocal designs, diffraction, pupil apodisation spherical aberration, and zone size influence both the effective add power and the pupil size required to balance near and distance image quality. Five-zone bifocal designs achieve a high degree of pupil size independence, and thus will provide more consistent performance as pupil size varies with light level and convergence amplitude. PMID:24588552

Ring-Interferometric Sol-Gel Bio-Sensor

NASA Technical Reports Server (NTRS)

Bearman, Gregory (Inventor); Cohen, David (Inventor)

2006-01-01

A biosensor embodying the invention includes a sensing volume having an array of pores sized for immobilizing a first biological entity tending to bind to a second biological entity in such a manner as to change an index of refraction of the sensing volume. The biosensor further includes a ring interferometer, one volumetric section of the ring interferometer being the sensing volume, a laser for supplying light to the ring interferometer, and a photodetector for receiving light from the interferometer.

Terrestrial Planet Finder Interferometer: Architecture, Mission Design, and Technology Development

NASA Technical Reports Server (NTRS)

Henry, Curt

2004-01-01

This slide presentation represents an overview progress report about the system design and technology development of two interferometer concepts studied for the Terrestrial Planet Finder (TPF) project. The two concepts are a structurally-connected interferometer (SCI) intended to fulfill minimum TPF science goals and a formation-flying interferometer (FFI) intended to fulfill full science goals. Described are major trades, analyses, and technology experiments completed. Near term plans are also described. This paper covers progress since August 2003

Fiber optic geophysical sensors

DOEpatents

Homuth, Emil F.

1991-01-01

A fiber optic geophysical sensor in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects.

Interferometer for Measuring Displacement to Within 20 pm

NASA Technical Reports Server (NTRS)

Zhao, Feng

2003-01-01

An optical heterodyne interferometer that can be used to measure linear displacements with an error <=20 pm has been developed. The remarkable accuracy of this interferometer is achieved through a design that includes (1) a wavefront split that reduces (relative to amplitude splits used in other interferometers) self interference and (2) a common-optical-path configuration that affords common-mode cancellation of the interference effects of thermal-expansion changes in optical-path lengths. The most popular method of displacement- measuring interferometry involves two beams, the polarizations of which are meant to be kept orthogonal upstream of the final interference location, where the difference between the phases of the two beams is measured. Polarization leakages (deviations from the desired perfect orthogonality) contaminate the phase measurement with periodic nonlinear errors. In commercial interferometers, these phase-measurement errors result in displacement errors in the approximate range of 1 to 10 nm. Moreover, because prior interferometers lack compensation for thermal-expansion changes in optical-path lengths, they are subject to additional displacement errors characterized by a temperature sensitivity of about 100 nm/K. Because the present interferometer does not utilize polarization in the separation and combination of the two interfering beams and because of the common-mode cancellation of thermal-expansion effects, the periodic nonlinear errors and the sensitivity to temperature changes are much smaller than in other interferometers

Pupils’ and teachers’ experiences of school-based physical education: a qualitative study

PubMed Central

Lewis, Kiara

2014-01-01

Objectives To explore pupils’ and teachers’ experiences of physical education (PE). Study design A qualitative investigation employing semistructured interviews. Self Determination Theory was used as a guiding theory and Template Analysis was used to analyse the data. Setting A secondary school in the North East of England. Participants 14 pupils (aged 13 and 14, boys and girls) with a range of self-perceived competencies regarding PE and four PE teachers of the pupils (3 male, 1 female). Primary and secondary outcomes (1) Attitudes and perceptions of PE pupils regarding their experiences of compulsory school PE lessons. (2) PE teachers’ experiences of teaching PE. Results Key results from pupils and teachers suggest pupils enjoy participation in PE when they feel competent, in control and supported by others. Feeling competent depended on (1) the activity within PE and (2) the pupils perceived physical capabilities/aptitude. Feeling in control related to (1) having a choice of activities, (2) being able to set exertion levels and (3) control over clothes worn while taking part. Relationships within pupil groups and between pupils and teachers were perceived as important. Teachers could positively influence their pupils’ enjoyment by understanding and supporting their personal goals, as opposed to dictating and controlling what they did and for how long, and by promoting a non-threatening atmosphere between pupils. Conclusions Rising obesity levels and concerns over the fitness of children and young people has returned the focus of PE to its potential as a vehicle for promoting health. This study suggests schools and PE teachers in particular can positively influence the PE experience of both boys and girls by providing more choice of activities and letting pupils make their own decisions based on their personal needs. PMID:25227625

The Effect of Light Level and Small Pupils on Presbyopic Reading Performance.

PubMed

Xu, Renfeng; Gil, Daniel; Dibas, Mohammed; Hare, William; Bradley, Arthur

2016-10-01

To examine the impact of small pupils and light levels on reading performance of distance-corrected presbyopes. To determine whether small pupils would enable presbyopes to read at near even at low light levels. To establish the lower range of text luminances, we quantified the space-averaged luminance of text in nine different artificially lit interior environments, and examined the impact of the text characters on space-averaged luminance of electronic and printed displays. Distance and near reading speeds of 20 presbyopes (ages 40-60 years) were measured while viewing through artificial pupils (diameters 1-4.5 mm), natural pupils, or with a multifocal contact lens. Space-averaged text luminance levels varied from 0.14 to 140 cd/m2 (including the range of measured environmental text luminances). Adding black text to a white computer display or paper reduces luminance by approximately 15% to 31%, and the lowest encountered environmental text luminance was approximately 2 to 3 cd/m2. For both distance and near reading performance, the 2- to 3-mm small pupil yielded the best overall reading acuity for space-averaged text light levels ≥ 2 cd/m2. The 2- to 3-mm artificial pupils and the multifocal contact lenses both enabled maximum or near-maximum reading speeds for 0.5 logMAR characters at distance and near, but with natural pupils, reading speeds were significantly reduced at near. Although photon noise at low luminance reduces the visual benefits of small pupils, the benefits of 2- to 3-mm artificial pupils are sufficient to enable >80% of distance-corrected presbyopes to read proficiently at near, even at the lowest text luminances found in interior environments.

Everything is ok on YouTube! Quality assessment of YouTube videos on the topic of phacoemulsification in eyes with small pupil.

PubMed

Aykut, Aslan; Kukner, Amber Senel; Karasu, Bugra; Palancıglu, Yeliz; Atmaca, Fatih; Aydogan, Tumay

2018-01-22

Usage of YouTube as an educational tool is gaining attention in academic research. To date, there has been no study on the content and quality of eye surgery videos on YouTube. The aim of this study was to analyze YouTube videos on phacoemulsification in eyes with small pupil. We searched for the phrases "small pupil cataract surgery," "small pupil phacoemulsification," "small pupil cataract surgery complications," and "small pupil phacoemulsification complications" in January 2015. Each resulting video was evaluated by all authors, and Krippendorff's alpha was calculated to measure agreement. Videos were classified according to pupil size (small/very small) in the beginning of the surgery, and whether pupillary diameter was large enough to continue surgery safely after pupillary dilation by the surgeon in the video (safe/not safe). Methods of dilatation were also analyzed. Any stated ocular comorbidity or surgical complications were noted. A total of 96 videos were reviewed. No mechanical intervention for pupillary dilatation was performed in 46 videos. Fifty-eight operated eyes had no stated ocular comorbidity. Ninety-five operations ended successfully without major complication. There was fair agreement between the evaluators regarding pupil sizes (Kα = 0.670) but poor agreement regarding safety (Kα = 0.337). YouTube videos on small pupil phacoemulsification have low complication rates when compared to the literature, although no reliable mechanical dilatation methods are used in almost half of these videos. Until YouTube's place in e-learning becomes clearer, we suggest that viewers be cautious regarding small pupil phacoemulsification videos on YouTube.

Year 7 dietary intake: a comparison of two schools with middle-high socio-economic status.

PubMed

Greatwood, H C; Daly-Smith, A; McGregor, S; McKenna, J

2013-12-01

With an established, yet avoidable, link between dietary intake and poor health, the nutritional habits of adolescents remains a public health concern. Previous studies report an inverse relationship between dietary intake and socio-economic status (SES), although few studies have considered the influence of the SES gradient. The present study compared the nutritional profiles of neighbouring schools with pupils from middle to high economic backgrounds. One hundred and ninety pupils from a high SES school (HSESS) and 159 pupils from a middle SES school (MSESS) (aged 11-12 years) completed a 63-item validated food frequency questionnaire. Pupils rated their diet quality and this was compared with a composite Healthy Eating Index (HEI). Children attending MSESS consumed significantly higher intakes of energy (P < 0.001), carbohydrate (P = 0.001), fat (P < 0.001) and protein (P = 0.001). As a percentage of energy contribution, pupils in both schools consumed excess saturated fat (HSESS, +5% boys, +4% girls; MSESS, +4% both boys and girls) and sugar (HSESS, +9% boys, +11% girls; MSESS, +10% boys, +11% girls). When HEI was compared with self-report diet quality, 96% HSESS pupils and 94% MSESS pupils over-rated the quality of their diet. The present study identified that, although pupils from MSESS consume a significantly higher intake of energy and macronutrient compared to a nearby HSESS, the percentage of energy contribution of saturated fat and sugar is above government recommendations for pupils from both schools. Additionally, the majority of pupils from both schools substantially over-rated their diet quality compared to a HEI. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association Ltd.

Pupil dilation dynamics with an intracameral fixed combination of mydriatics and anesthetic during cataract surgery.

PubMed

Chiambaretta, Frederic; Pleyer, Uwe; Behndig, Anders; Pisella, Pierre-Jean; Mertens, Erik; Limao, Antonio; Fasce, Francesco; Fernandez, Joaquin; Benmoussa, Salah-Eddine; Labetoulle, Marc; Cochener, Beatrice

2018-03-01

To compare the pupil dynamics of an intracameral combination of 2 mydriatics and 1 anesthetic (Mydrane) to a standard topical regimen for cataract surgery. Sixty-two centers in Europe and 6 centers in Algeria. Prospective case series. Pupil size measurements were performed in 2 randomized studies (phase 2 and phase 3) under masked conditions (recorded videography, masked reading center). The outcomes in the phase 2 study supported evaluation of the timeframe to obtain pupil dilation and the phase 3 study provided results on mydriasis stability. Phase 2 and phase 3 comprised 139 patients and 591 patients, respectively. After intracameral combination administration, 95% of the pupil dilation was achieved within a mean of 28.6 seconds ± 4.6 (SD). At the beginning of capsulorhexis creation, the mean pupil diameter was larger than 7.0 mm in both groups. The intraoperative pupil diameter remained stable in the intracameral combination group and decreased in the topical group. The mean change in pupil size just before capsulorhexis to the end of surgery (just before cefuroxime injection) was -0.22 ± 0.72 mm and -1.67 ± 0.98 mm, respectively. No clinically significant change in pupil diameter (change <1.0 mm) occurred in the majority of the intracameral combination group (89.3%) compared with the topical group (26.8%). Intracameral combination of 2 mydriatics and 1 anesthetic is an alternative to topical mydriatics for cataract surgery. The prompt onset of pupil dilation and the stable mydriasis induced by this drug combination improved the intraoperative conditions during crucial steps, such as intraocular lens implantation. Copyright © 2018. Published by Elsevier Inc.

The pupillary light responses of animals; a review of their distribution, dynamics, mechanisms and functions.

PubMed

Douglas, Ronald H

2018-05-01

The timecourse and extent of changes in pupil area in response to light are reviewed in all classes of vertebrate and cephalopods. Although the speed and extent of these responses vary, most species, except the majority of teleost fish, show extensive changes in pupil area related to light exposure. The neuromuscular pathways underlying light-evoked pupil constriction are described and found to be relatively conserved, although the precise autonomic mechanisms differ somewhat between species. In mammals, illumination of only one eye is known to cause constriction in the unilluminated pupil. Such consensual responses occur widely in other animals too, and their function and relation to decussation of the visual pathway is considered. Intrinsic photosensitivity of the iris muscles has long been known in amphibia, but is in fact widespread in other animals. The functions of changes in pupil area are considered. In the majority of species, changes in pupil area serve to balance the conflicting demands of high spatial acuity and increased sensitivity in different light levels. In the few teleosts in which pupil movements occur they do not serve a visual function but play a role in camouflaging the eye of bottom-dwelling species. The occurrence and functions of the light-independent changes in pupil size displayed by many animals are also considered. Finally, the significance of the variations in pupil shape, ranging from circular to various orientations of slits, ovals, and other shapes, is discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Frequency and Efficacy of Talk-Related Tasks in Primary Science

NASA Astrophysics Data System (ADS)

Braund, Martin; Leigh, Joanne

2013-04-01

Pupil talk and discussion are seen as having important social and cognitive outcomes. In science classes, pupils' collaborative talk supports the construction of meaning and helps examine the status of evidence, theory and knowledge. However, pupil interactive talk in groups is rare in science lessons. The research reported is part of a project to increase the amount of pupil-pupil talk in primary schools through a programme of teaching and professional development. Pupils' self-reports of the frequency and learning efficacies of talk related activities in science lessons were collected before and after a programme of teaching in 24 schools in one of the most socially and educationally deprived areas of England. Findings showed pupils valued talking about their ideas over listening to those of other pupils. Science talk frequency (STF) was closely correlated with science talk efficacy (STE) and both were positively correlated with pupils' attitudes to school science. Analysis of covariance (ANCOVA) of the correlation of STF with STE showed values were independent of gender and ability but that school experience was a significant factor. After the teaching programme and, contrary to expectations, the frequency of talk activities in science lessons appeared to have decreased but varied according to class grades. The degree of correlation between STF and STE was stronger after the teaching in over half of the schools. Schools where STF/STE strengthened most as a result of teaching were those involved in an additional initiative to use modelled talk related to industrial contexts.

Observations of teachers in Ilorin, Nigeria on their practices of corporal punishment that are potentially injurious to their pupils' eyes.

PubMed

Mahmoud, Abdulraheem Olarongbe; Ayanniyi, Abdulkabir Ayansiji; Salman, Medinat Folorunso

2011-01-01

To document the observations of elementary school teachers (ESTs) in Ilorin, Nigeria on their practice of some types of corporal punishment (CP) that could result in eye injuries among their pupils. A short battery of questions that explored ESTs' observations on attitudes to, and knowledge of some commonly used CP practices was self-administered on 172 consenting teachers from six sampled schools. The potentials for their pupils to sustain eye injuries while receiving such CP practices were inferred from the usage of items with sharp and protruding ends to administer CP, and the application of CP onto pupils' body parts that are in close proximity to the eye such as the head and face. Only 50 of the 172 ESTs favored the practice of CP of pupils by their teachers. Analyses of several potentially moderating variables on this response such as ESTs' ages, years of EST teaching experience, school, and class or grade that EST teaches did not prove significant. Over three-quarters of ESTs (80.2%) had ever observed that pupils were being disciplined by ESTs with a cane. About a fifth of them had also observed that ESTs applied CP to the head (19.8%) and the face (16.3%) of pupils. Findings suggest that ESTs' commonly employed CP practices have significant injurious potential to their pupils' eyes. It is recommended that CP be abolished in elementary schools, and instead alternative nonabusive methods of disciplining erring pupils by teachers be introduced.

A NEW CONCEPT FOR SPECTROPHOTOMETRY OF EXOPLANETS WITH SPACE-BORNE TELESCOPES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuo, Taro; Itoh, Satoshi; Shibai, Hiroshi

2016-06-01

We propose a new concept for the spectral characterization of transiting exoplanets with future space-based telescopes. This concept, called densified pupil spectroscopy, allows us to perform high, stable spectrophotometry against telescope pointing jitter and deformation of the primary mirror. This densified pupil spectrometer comprises the following three roles: division of a pupil into a number of sub-pupils, densification of each sub-pupil, and acquisition of the spectrum of each sub-pupil with a conventional spectrometer. Focusing on the fact that the divided and densified sub-pupil can be treated as a point source, we discovered that a simplified spectrometer allows us to acquiremore » the spectra of the densified sub-pupils on the detector plane−an optical conjugate with the primary mirror−by putting the divided and densified sub-pupils on the entrance slit of the spectrometer. The acquired multiple spectra are not principally moved on the detector against low-order aberrations such as the telescope pointing jitter and any deformation of the primary mirror. The reliability of the observation result is also increased by statistically treating them. Our numerical calculations show that because this method suppresses the instrumental systematic errors down to 10 ppm under telescopes with modest pointing accuracy, next generation space telescopes with more than 2.5 m diameter potentially provide opportunities to characterize temperate super-Earths around nearby late-type stars through the transmission spectroscopy and secondary eclipse.« less

Atise: a miniature Fourier-transform spectro-imaging concept for surveying auroras and airglow monitoring from a 6/12u cubesat

NASA Astrophysics Data System (ADS)

Le Courer, E.; Barthelemy, M.; Vialatte, A.; Prugniaux, M.; Bourdarot, G.; Sequies, T.; Monsinjon, P.; Puget, R.; Guerineau, N.

2017-09-01

The nanosatellite ATISE is a mission dedicated to the observation of the emission spectra of the upper atmosphere (i.e. Airglow and Auroras) mainly related to both the solar UV flux and the precipitation of suprathermal particles coming from the solar wind through the magnetosphere. ATISE will measure specifically the auroral emissions, and the airglow (day- and night) in the spectral range between 380 and 900 nm at altitudes between 100 and 350 km. The exposure time will be 1 second in auroral region and 20 s at low latitude regions. The 5 year expected lifetime of this mission should cover almost a half of solar cycle (2 years nominal). This instrument concept is based on an innovative miniaturized Fourier-transform spectrometer (FTS) allowing simultaneous 1 Rayleigh sensitivity detection along six 1.5°x1° limb lines of sight. This 1-2kg payload instrument is hosted in a 12U cubeSat where 6U are allocated to the payload and 6U to the plateform subsystems. This represents a miniaturisation by a factor of 500 on weight and volume compared to previous Arizona-GLO instrument for equivalent performances in the visible. The instrument is based on microSPOC concept developed by ONERA and IPAG using one Fizeau interferometer per line of sight directly glued on top of the half of a very sensitive CMOS Pyxalis HDPYX detector. Three detectors are necessary with a total electrical consumption compatible with a 6U nanoSat. Each interferometer occupies a 1.4 M pixel part of detector, each is placed on an image of the entrance pupil corresponding to a unique direction of the six lines of sight, this in order to have a uniform illumination permitting good spectral Fourier reconstruction from fringes created between the Fizeau plate and the detector itself. Despite a limited 8x6 cm telescope, this configuration takes advantage of FTS multiplex effect and permits us to maximize the throughput and to integrate very faint emission lines over a wide field of view even if the 1 second integrated signal is comparable to the detector noise.

Atom Interferometry: A Matter Wave Clock and a Measurement of α

NASA Astrophysics Data System (ADS)

Estey, Brian; Lan, Shau-Yu; Kuan, Pei-Chen; Hohensee, Michael; Haslinger, Philipp; Kehayias, Pauli; English, Damon; Müller, Holger

2012-06-01

Developments in large-momentum transfer beamsplitters (eg. Bragg diffraction) and conjugate Ramsey-Bord'e interferometers have enabled atom interferometers with unparalleled size and sensitivity. The atomic wave packet separation is large enough that the Coriolis force due to the earth's rotation reduces interferometer contrast. We compensate for this effect using a tip-tilt mirror, improving our contrast by up to a factor of 3.5, allowing pulse separations of up to 250 ms with 10k beamsplitters. This interferometer can be used to make a precise measurement of the recoil frequency (h/m) and thus the fine structure constant. The interferometer also gives us indirect access to the Compton frequency (νC≡mc^2/h) oscillations of the matter wave, since h/m is simply c^2/νC. Using an optical frequency comb we reference the interferometer's laser frequency to a multiple of a cesium atom's recoil frequency. This self-referenced interferometer thus locks a local oscillator to a specified fraction of the cesium Compton frequency, with a fractional stability of 2 pbb over several hours. This has potential application in redefining the kilogram in terms of the second. We also present a preliminary measurement of the fine structure constant.

Candidates for a possible third-generation gravitational wave detector: comparison of ring-Sagnac and sloshing-Sagnac speedmeter interferometers

NASA Astrophysics Data System (ADS)

Huttner, S. H.; Danilishin, S. L.; Barr, B. W.; Bell, A. S.; Gräf, C.; Hennig, J. S.; Hild, S.; Houston, E. A.; Leavey, S. S.; Pascucci, D.; Sorazu, B.; Spencer, A. P.; Steinlechner, S.; Wright, J. L.; Zhang, T.; Strain, K. A.

2017-01-01

Speedmeters are known to be quantum non-demolition devices and, by potentially providing sensitivity beyond the standard quantum limit, become interesting for third generation gravitational wave detectors. Here we introduce a new configuration, the sloshing-Sagnac interferometer, and compare it to the more established ring-Sagnac interferometer. The sloshing-Sagnac interferometer is designed to provide improved quantum noise limited sensitivity and lower coating thermal noise than standard position meter interferometers employed in current gravitational wave detectors. We compare the quantum noise limited sensitivity of the ring-Sagnac and the sloshing-Sagnac interferometers, in the frequency range, from 5 Hz to 100 Hz, where they provide the greatest potential benefit. We evaluate the improvement in terms of the unweighted noise reduction below the standard quantum limit, and by finding the range up to which binary black hole inspirals may be observed. The sloshing-Sagnac was found to give approximately similar or better sensitivity than the ring-Sagnac in all cases. We also show that by eliminating the requirement for maximally-reflecting cavity end mirrors with correspondingly-thick multi-layer coatings, coating noise can be reduced by a factor of approximately 2.2 compared to conventional interferometers.

''I Don't Think I Would Be Where I Am Right Now''. Pupil Perspectives on Using Mobile Devices for Learning

ERIC Educational Resources Information Center

Walker, Ros

2013-01-01

Are pupils in the United Kingdom using mobile devices to help their learning? If so, what are they using and why? This article is based on research carried out by questionnaire, observation and pupil interviews at two English academies. One of the academies provides mobile devices for the pupils, and the other bans the use of mobile devices. The…

Configuration and Dynamics of the Earth-Sun-Moon System: An Investigation into Conceptions of Deaf and Hearing Pupils.

ERIC Educational Resources Information Center

Roald, Ingvild; Mikalsen, Oyvind

2001-01-01

Reports and analyzes the day and night cycle, the seasons, and the phases of the moon as seen by Norwegian deaf pupils aged 7, 9, 11, and 17 years, and by hearing Norwegian pupils 9 years old. Among the 9-year-olds there was no difference in the inner coherence of the conceptions between deaf pupils. (Author/SAH)

What Are the Earth and the Heavenly Bodies Like? A Study of Objectual Conceptions among Norwegian Deaf and Hearing Pupils.

ERIC Educational Resources Information Center

Roald, Ingvild; Mikalsen, Oyvind

2000-01-01

Addresses deaf pupils' conceptions of directly-observed phenomena of the earth and sky. Studies 7-, 9-, 11-, and 17-year-old deaf pupils and uses 9-year-old Norwegian pupils with normal hearing as the control group. Reports that the children's conceptions are scientifically accepted. Indicates that the shape of the sign representing an object may…

Performing below the Targeted Level: An Investigation into KS3 Pupils' Attitudes towards Mathematics

ERIC Educational Resources Information Center

Mirza, Anusha; Hussain, Nasreen

2018-01-01

This study sets out to investigate the attitude KS3 pupils have towards mathematics and the factors that influence this attitude. A case study approach was used as the pupils were a unit of the school under study and a survey method was chosen to provide scope to the study. Purposeful sampling was employed for the selection of 200 pupils from…

A Picture Is Worth a Thousand Words: A Comparison of Pupils' Images of Intelligence in Finnish and Russian Karelia

ERIC Educational Resources Information Center

Raty, Hannu; Komulainen, Katri; Skorokhodova, Nina; Kolesnikov, Vadim; Hamalainen, Anna

2011-01-01

The study set out to examine Finnish and Russian children's images of intelligence as contextualized in the systems of the school and gender. Finnish and Russian pupils, aged 11-12 years, were asked to draw pictures of an intelligent and an ordinary pupil and a good and an ordinary pupil. A distinctive feature shared by the children in both…

Disentangling reward anticipation with simultaneous pupillometry / fMRI.

PubMed

Schneider, Max; Leuchs, Laura; Czisch, Michael; Sämann, Philipp G; Spoormaker, Victor I

2018-05-05

The reward system may provide an interesting intermediate phenotype for anhedonia in affective disorders. Reward anticipation is characterized by an increase in arousal, and previous studies have linked the anterior cingulate cortex (ACC) to arousal responses such as dilation of the pupil. Here, we examined pupil dynamics during a reward anticipation task in forty-six healthy human subjects and evaluated its neural correlates using functional magnetic resonance imaging (fMRI). Pupil size showed a strong increase during monetary reward anticipation, a moderate increase during verbal reward anticipation and a decrease during control trials. For fMRI analyses, average pupil size and pupil change were computed in 1-s time bins during the anticipation phase. Activity in the ventral striatum was inversely related to the pupil size time course, indicating an early onset of activation and a role in reward prediction processing. Pupil dilations were linked to increased activity in the salience network (dorsal ACC and bilateral insula), which likely triggers an increase in arousal to enhance task performance. Finally, increased pupil size preceding the required motor response was associated with activity in the ventral attention network. In sum, pupillometry provides an effective tool for disentangling different phases of reward anticipation, with relevance for affective symptomatology. Copyright © 2018 Elsevier Inc. All rights reserved.

Decreased retinal sensitivity in depressive disorder: a controlled study.

PubMed

Berman, G; Muttuvelu, D; Berman, D; Larsen, J I; Licht, R W; Ledolter, J; Kardon, R H

2018-03-01

To compare pupil responses in depressed patients with a seasonal pattern, depressed patients without a seasonal pattern and healthy controls as a function of daylight hours on the testing day. Patients suffering from a major depressive episode were included in wintertime. The pupil light reflex was measured at inclusion and in the following summer using a binocular pupillometer. A protocol of low (1 lux) and high (400 lux) intensity red and blue lights was used to assess rod, cone and melanopsin-containing intrinsic photosensitive retinal ganglion cell input to the pupil reflex. The mean group pupil responses associated with a melanopsin-mediated sustained pupil response at 400 lux blue light were significantly reduced in the depressed subjects (N = 39) as compared to the healthy controls (N = 24) (P = 0.023). Across all groups, a reduction in number of daylight hours was significantly associated with a reduction in sustained pupil response (P = 0.007). All groups showed an equal effect of daylight hours on the melanopsin-mediated sustained pupil response. The melanopsin-mediated sustained pupil contraction to offset of high-intensity blue light is reduced in depressed patients. These results further emphasize the interaction of light exposure with depression. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Science investigation: the views of 14 to 16 year old pupils

NASA Astrophysics Data System (ADS)

Toplis, Rob; Cleaves, Anna

2006-05-01

This paper reports research about upper secondary school pupils' views about science investigations in school. Although researchers, teachers and examiners have expressed opinions about investigative work in science, there have been relatively few studies of pupils' experiences. The present study identified pupils' concerns about the limited time available, timing of the investigations, lack of familiarity with apparatus and the association of investigation almost exclusively with assessment, all factors which contributed to stress. One exceptional school apart, pupils perceived the teacher's role as a didactic supporter of strategies to maximise performance for assessment. We discuss these views and examine the potential for putting policy into practice.

Gravitational Wave Detection with Single-Laser Atom Interferometers

NASA Technical Reports Server (NTRS)

Yu, Nan; Tinto, Massimo

2011-01-01

A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.

Special topics in infrared interferometry. [Michelson interferometer development

NASA Technical Reports Server (NTRS)

Hanel, R. A.

1985-01-01

Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

High sensitivity boundary layer transition detector

NASA Technical Reports Server (NTRS)

Azzazy, M.; Modarress, D.; Hoeft, T.

1985-01-01

A high sensitivity differential interferometer has been developed to locate the region where the boundary layer flow changes from laminar to turbulent. Two experimental configurations have been used to evaluate the performance of the interferometer, open shear layer configuration and wind tunnel turbulent spot configuration. In each experiment small temperature fluctuations were introduced as the signal source. Simultaneous cold wire measurements have been compared with the interferometer data. The comparison shows that the interferometer is sensitive to very weak phase variations in the order of .001 the laser wavelength.

Results from a Grazing Incidence X-Ray Interferometer

NASA Technical Reports Server (NTRS)

Joy, Marshall K.; Shipley, Ann; Cash, Webster; Carter, James

2000-01-01

A prototype grazing incidence interferometer has been built and tested at EUV and X-ray wavelengths using a 120 meter long vacuum test facility at Marshall Space Flight Center. We describe the design and construction of the interferometer, the EUV and x-ray sources, the detector systems, and compare the interferometric fringe measurements with theoretical predictions. We also describe the next-generation grazing incidence system which is designed to provide laboratory demonstration of key technologies that will be needed for a space-based x-ray interferometer.

Fiber optic geophysical sensors

DOEpatents

Homuth, E.F.

1991-03-19

A fiber optic geophysical sensor is described in which laser light is passed through a sensor interferometer in contact with a geophysical event, and a reference interferometer not in contact with the geophysical event but in the same general environment as the sensor interferometer. In one embodiment, a single tunable laser provides the laser light. In another embodiment, separate tunable lasers are used for the sensor and reference interferometers. The invention can find such uses as monitoring for earthquakes, and the weighing of objects. 2 figures.

Pupil diameter as predictor of cognitive load: A novel tool for geoscience education research

NASA Astrophysics Data System (ADS)

Mitra, R.; McNeal, K.

2015-12-01

Pupils can truly serve as windows to the mind. Since the early part of the last decade, pupillometry, the study of pupils in response to cognitive tasks, have gained traction in psychophysiological studies. Muscles of the iris work in tandem with the autonomic nervous system in response to light condition to either dilate or contract the pupil, usually between 2 to 7 mm. Along with this response to light conditions, the pupils also contract or dilate in response to emotional or mental response. Therefore, for a cognitive task, if the ambient brightness is controlled, pupil dilation reflects the cognitive load associated with the task. Simple tasks such as counting, memorizing, multiplying and visual searching have been found to have pupillometry profiles reflective of the cognitive load involved with such tasks. In this study, we investigate whether pupil diameter can be used for education research where tasks can be more complex. In particular, we look at two specific types of tasks common in geoscience and several other STEM fields: graph reading and spatial problem solving.

Balloon Exoplanet Nulling Interferometer (BENI)

NASA Technical Reports Server (NTRS)

Lyon, Richard G.; Clampin, Mark; Woodruff, Robert A.; Vasudevan, Gopal; Ford, Holland; Petro, Larry; Herman, Jay; Rinehart, Stephen; Carpenter, Kenneth; Marzouk, Joe

2009-01-01

We evaluate the feasibility of using a balloon-borne nulling interferometer to detect and characterize exosolar planets and debris disks. The existing instrument consists of a 3-telescope Fizeau imaging interferometer with 3 fast steering mirrors and 3 delay lines operating at 800 Hz for closed-loop control of wavefront errors and fine pointing. A compact visible nulling interferometer is under development which when coupled to the imaging interferometer would in-principle allow deep suppression of starlight. We have conducted atmospheric simulations of the environment above 100,000 feet and believe balloons are a feasible path forward towards detection and characterization of a limited set of exoplanets and their debris disks. Herein we will discuss the BENI instrument, the balloon environment and the feasibility of such as mission.

Analysis of the localization of Michelson interferometer fringes using Fourier optics and temporal coherence

NASA Astrophysics Data System (ADS)

Narayanamurthy, C. S.

2009-01-01

Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in Principles of Optics by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer have never been analysed seriously in any book. Because Michelson's interferometer is one of the important and fundamental optical experiments taught at both undergraduate and graduate levels, it would be appropriate to explain the localization of these fringes. In this paper, we analyse the localization of Michelson interferometer fringes using Fourier optics and temporal coherence, and show that they never localize at any plane even at infinity.

A chevron beam-splitter interferometer

NASA Technical Reports Server (NTRS)

Breckinridge, J. B.

1979-01-01

Fully tilt compensated double-pass chevron beam splitter, that removes channelling effects and permits optical phase tuning, is wavelength independent and allows small errors in alignment that are not tolerated in Michelson, Machzender, or Sagnac interferometers. Device is very useful in experiments where background vibration affects conventional interferometers.

High resolution Fourier interferometer-spectrophotopolarimeter

NASA Technical Reports Server (NTRS)

Fymat, A. L. (Inventor)

1976-01-01

A high-resolution Fourier interferometer-spectrophotopolarimeter is provided using a single linear polarizer-analyzer the transmission axis azimuth of which is positioned successively in the three orientations of 0 deg, 45 deg, and 90 deg, in front of a detector; four flat mirrors, three of which are switchable to either of two positions to direct an incoming beam from an interferometer to the polarizer-analyzer around a sample cell transmitted through a medium in a cell and reflected by medium in the cell; and four fixed focussing lenses, all located in a sample chamber attached at the exit side of the interferometer. This arrangement can provide the distribution of energy and complete polarization state across the spectrum of the reference light entering from the interferometer; the same light after a fixed-angle reflection from the sample cell containing a medium to be analyzed; and the same light after direct transmission through the same sample cell, with the spectral resolution provided by the interferometer.

Study of the second-order relativistic light deflection of the Sun using long-baseline fibre-linked interferometers: Laser-Interferometric Solar Relativity (LISOR) test

NASA Technical Reports Server (NTRS)

Ni, Wei-Tou; Shy, Jow-Tsong; Tseng, Shiao-Min; Shao, Michael

1992-01-01

A propasal to study the second order light deflection in the solar gravitational field is presented. It is proposed to use 1 to 2 W frequency stabilized lasers on two microspacecraft about 0.25 degree apart in the sky with apparent positions near the Sun, and observe the relative angle of two spacecraft using ground based fiber linked interferometers with 10 km baseline to determine the second order relativistic light deflection effects. The first two years of work would emphasize the establishment of a prototype stabilized laser system and fiber linked interferometer. The first year, a prototype fiber linked interferometer would be set up to study the phase noise produced by external perturbations to fiber links. The second year, a second interferometer would be set up. The cancellation of phase drift due to fiber links of both interferometers in the same environment would be investigated.

Pupils' Perceptions of the Foreign Language Learning Experience.

ERIC Educational Resources Information Center

Chambers, Gary N.

1998-01-01

Presents findings relating to a study on pupils' perceptions of the in-school foreign language learning experience. The study is part of a longitudinal study on the motivational perspectives of secondary pupils learning German. (Author/VWL)

Longitudinal Effects of Class Size Reductions on Attainment: Results from Hong Kong Primary Classrooms

ERIC Educational Resources Information Center

Galton, Maurice; Pell, Tony

2012-01-01

In a four-year study of the effect of class size on pupil outcomes in a sample of 36 primary schools in Hong Kong, it has been found that there are few positive differences in attainment between classes set at less than 25 pupils and those of normal size averaging 38. Three cohorts of pupils were studied. In Cohort 1 pupils spent 3 years in small…

Using Pupil Diameter Changes for Measuring Mental Workload under Mental Processing

NASA Astrophysics Data System (ADS)

Batmaz, Ihsan; Ozturk, Mustafa

In this study, it is aimed to evaluate the mental workload by using a practical way which based on measuring pupil diameter changes that occurs under mental processing. To determine the mental effort required for each task, the video record of subjects` eyes are taken while they are performed different tasks and pupils were measured from the records. A group of university student, one female 9 males participated to the experiment. Additionally, NASA-TLX questionnaire is applied for the related mental tasks. For verification of results obtained from both indices, the correlation coefficient is calculated task base. The results show that there is weak and negative correlation between the indices on task base except 3rd task. By investigating pupil diameter measurements data too, it is founded that pupil dilates under mental workload during performing related tasks. For all tasks, pupil diameters of response periods increased according to reference baseline period.

Future engineers: the intrinsic technology motivation of secondary school pupils

NASA Astrophysics Data System (ADS)

Jones, Lewis C. R.; McDermott, Hilary J.; Tyrer, John R.; Zanker, Nigel P.

2018-07-01

The supply of students motivated to study engineering in higher education is critical to the sector. Results are presented from the 'Mindsets STEM Enhancement Project'. Fifty-seven new resources packs, designed to improve STEM education in Design and Technology, were given to schools across London. A modified Intrinsic Motivation Inventory questionnaire measured pupils' (n = 458) motivation towards technology. The results show that although pupils have positive reactions to the technology content within Design and Technology lessons, the type of STEM resources and lessons created through the project had made no significant difference on pupils' interest/enjoyment towards technology. This suggests stand-alone resources do not improve pupil motivation. The impact of this work to engineering higher education is that the existing levels and the inability to improve pupil motivation in technology at school could be a factor affecting the pursuit of a technology or engineering related education or career.

Aberration correction in wide-field fluorescence microscopy by segmented-pupil image interferometry.

PubMed

Scrimgeour, Jan; Curtis, Jennifer E

2012-06-18

We present a new technique for the correction of optical aberrations in wide-field fluorescence microscopy. Segmented-Pupil Image Interferometry (SPII) uses a liquid crystal spatial light modulator placed in the microscope's pupil plane to split the wavefront originating from a fluorescent object into an array of individual beams. Distortion of the wavefront arising from either system or sample aberrations results in displacement of the images formed from the individual pupil segments. Analysis of image registration allows for the local tilt in the wavefront at each segment to be corrected with respect to a central reference. A second correction step optimizes the image intensity by adjusting the relative phase of each pupil segment through image interferometry. This ensures that constructive interference between all segments is achieved at the image plane. Improvements in image quality are observed when Segmented-Pupil Image Interferometry is applied to correct aberrations arising from the microscope's optical path.

Cigarette access and pupil smoking rates: a circular relationship?

PubMed

Turner, Katrina M; Gordon, Jacki; Young, Robert

2004-12-01

Adolescents obtain cigarettes from both commercial and social sources. While the relationship between commercial access and adolescent smoking has been researched, no one has considered in detail whether rates of peer smoking affect cigarette availability. In two relatively deprived Scottish schools that differed in their pupil smoking rates, we assess pupil access to cigarettes. 896 13 and 15 year olds were surveyed, and 25 single-sex discussion groups held with a sub-sample of the 13 year olds. Smokers in both schools obtained cigarettes from shops, food vans and other pupils. However, pupils in the 'high' smoking school perceived greater access to both commercial and social sources, and had access to an active 'peer market'. These findings suggest that variations in cigarette access may contribute to school differences in pupil smoking rates, and that the relationship between access and adolescent smoking is circular, with greater availability increasing rates, and higher rates enhancing access.

Intrinsically photosensitive retinal ganglion cell function in relation to age: A pupillometric study in humans with special reference to the age-related optic properties of the lens

PubMed Central

2012-01-01

Background The activity of melanopsin containing intrinsically photosensitive ganglion retinal cells (ipRGC) can be assessed by a means of pupil responses to bright blue (appr.480 nm) light. Due to age related factors in the eye, particularly, structural changes of the lens, less light reaches retina. The aim of this study was to examine how age and in vivo measured lens transmission of blue light might affect pupil light responses, in particular, mediated by the ipRGC. Methods Consensual pupil responses were explored in 44 healthy subjects aged between 26 and 68 years. A pupil response was recorded to a continuous 20 s light stimulus of 660 nm (red) or 470 nm (blue) both at 300 cd/m2 intensity (14.9 and 14.8 log photons/cm2/s, respectively). Additional recordings were performed using four 470 nm stimulus intensities of 3, 30, 100 and 300 cd/m2. The baseline pupil size was measured in darkness and results were adjusted for the baseline pupil and gender. The main outcome parameters were maximal and sustained pupil contraction amplitudes and the postillumination response assessed as area under the curve (AUC) over two time-windows: early (0–10 s after light termination) and late (10–30 s after light termination). Lens transmission was measured with an ocular fluorometer. Results The sustained pupil contraction and the early poststimulus AUC correlated positively with age (p = 0.02, p = 0.0014, respectively) for the blue light stimulus condition only. The maximal pupil contraction amplitude did not correlate to age either for bright blue or red light stimulus conditions. Lens transmission decreased linearly with age (p < 0.0001). The pupil response was stable or increased with decreasing transmission, though only significantly for the early poststimulus AUC to 300 cd/m2 light (p = 0.02). Conclusions Age did not reduce, but rather enhance pupil responses mediated by ipRGC. The age related decrease of blue light transmission led to similar results, however, the effect of age was greater on these pupil responses than that of the lens transmission. Thus there must be other age related factors such as lens scatter and/or adaptive processes influencing the ipRGC mediated pupil response enhancement observed with advancing age. PMID:22471313

Fine-grained versus categorical: Pupil size differentiates between strategies for spatial working memory performance.

PubMed

Starc, Martina; Anticevic, Alan; Repovš, Grega

2017-05-01

Pupillometry provides an accessible option to track working memory processes with high temporal resolution. Several studies showed that pupil size increases with the number of items held in working memory; however, no study has explored whether pupil size also reflects the quality of working memory representations. To address this question, we used a spatial working memory task to investigate the relationship of pupil size with spatial precision of responses and indicators of reliance on generalized spatial categories. We asked 30 participants (15 female, aged 19-31) to remember the position of targets presented at various locations along a hidden radial grid. After a delay, participants indicated the remembered location with a high-precision joystick providing a parametric measure of trial-to-trial accuracy. We recorded participants' pupil dilations continuously during task performance. Results showed a significant relation between pupil dilation during preparation/early encoding and the precision of responses, possibly reflecting the attentional resources devoted to memory encoding. In contrast, pupil dilation at late maintenance and response predicted larger shifts of responses toward prototypical locations, possibly reflecting larger reliance on categorical representation. On an intraindividual level, smaller pupil dilations during encoding predicted larger dilations during late maintenance and response. On an interindividual level, participants relying more on categorical representation also produced larger precision errors. The results confirm the link between pupil size and the quality of spatial working memory representation. They suggest compensatory strategies of spatial working memory performance-loss of precise spatial representation likely increases reliance on generalized spatial categories. © 2017 Society for Psychophysiological Research.

Pupils' over-reliance on linearity: a scholastic effect?

PubMed

Van Dooren, Wim; De Bock, Dirk; Janssens, Dirk; Verschaffel, Lieven

2007-06-01

From upper elementary education on, children develop a tendency to over-use linearity. Particularly, it is found that many pupils assume that if a figure enlarges k times, the area enlarges k times too. However, most research was conducted with traditional, school-like word problems. This study examines whether pupils also over-use linearity if non-linear problems are embedded in meaningful, authentic performance tasks instead of traditional, school-like word problems, and whether this experience influences later behaviour. Ninety-three sixth graders from two primary schools in Flanders, Belgium. Pupils received a pre-test with traditional word problems. Those who made a linear error on the non-linear area problem were subjected to individual interviews. They received one new non-linear problem, in the S-condition (again a traditional, scholastic word problem), D-condition (the same word problem with a drawing) or P-condition (a meaningful performance-based task). Shortly afterwards, pupils received a post-test, containing again a non-linear word problem. Most pupils from the S-condition displayed linear reasoning during the interview. Offering drawings (D-condition) had a positive effect, but presenting the problem as a performance task (P-condition) was more beneficial. Linear reasoning was nearly absent in the P-condition. Remarkably, at the post-test, most pupils from all three groups again applied linear strategies. Pupils' over-reliance on linearity seems partly elicited by the school-like word problem format of test items. Pupils perform much better if non-linear problems are offered as performance tasks. However, a single experience does not change performances on a comparable word problem test afterwards.

Numerical stress analysis of the iris tissue induced by pupil expansion: Comparison of commercial devices

PubMed Central

Wang, Xiaofei; Perera, Shamira A.; Girard, Michaël J. A.

2018-01-01

Purpose (1) To use finite element (FE) modelling to estimate local iris stresses (i.e. internal forces) as a result of mechanical pupil expansion; and to (2) compare such stresses as generated from several commercially available expanders (Iris hooks, APX dilator and Malyugin ring) to determine which design and deployment method are most likely to cause iris damage. Methods We used a biofidelic 3-part iris FE model that consisted of the stroma, sphincter and dilator muscles. Our FE model simulated expansion of the pupil from 3 mm to a maximum of 6 mm using the aforementioned pupil expanders, with uniform circular expansion used for baseline comparison. FE-derived stresses, resultant forces and area of final pupil opening were compared across devices for analysis. Results Our FE models demonstrated that the APX dilator generated the highest stresses on the sphincter muscles, (max: 6.446 MPa; average: 5.112 MPa), followed by the iris hooks (max: 5.680 MPa; average: 5.219 MPa), and the Malyugin ring (max: 2.144 MPa; average: 1.575 MPa). Uniform expansion generated the lowest stresses (max: 0.435MPa; average: 0.377 MPa). For pupil expansion, the APX dilator required the highest force (41.22 mN), followed by iris hooks (40.82 mN) and the Malyugin ring (18.56 mN). Conclusion Our study predicted that current pupil expanders exert significantly higher amount of stresses and forces than required during pupil expansion. Our work may serve as a guide for the development and design of next-generation pupil expanders. PMID:29538452

Integrated STEM in secondary education: A case study

NASA Astrophysics Data System (ADS)

De Meester, Jolien; Knipprath, Heidi; Thielemans, Jan; De Cock, Mieke; Langie, Greet; Dehaene, Wim

2016-05-01

Despite many opportunities to study STEM (Science, Technology, Engineering & Mathematics) in Flemish secondary education, only a minority of pupils are actually pursuing STEM fields in higher education and jobs. One reason could be that they do not see the relevance of science and mathematics. In order to draw their pupils' interest in STEM, a Belgian school started a brand new initiative: the school set up and implemented a first year course that integrates various STEM disciplines, hoping to provide an answer to the question pupils often ask themselves about the need to study math and science. The integrated curriculum was developed by the school's teachers and a STEM education research group of the University of Leuven. To examine the pupils' attitude towards STEM and STEM professions and their notion of relevance of STEM at the end of this one-year course, a post-test was administered to the group of pupils who attended the integrated STEM course (the experimental group) and to a group of pupils that took traditional, non-integrated STEM courses (the control group). The results reveal that attending the integrated STEM course is significantly related to pupils' interest in STEM and notion of relevance of STEM. Another post-test was administered only to the experimental group to investigate pupils' understanding of math and physics concepts and their relation when taught in an integrated way. The results reveal that the pupils have some conceptual understanding and can, to a certain extent, make a transfer of concepts across different STEM disciplines. However, the test results did point out that some additional introductory training in pure math context is needed.

Riparian habitat change along the Isleta-Belen reach of the Rio Grande

Treesearch

Joanne Mount; William Krausman; Deborah M. Finch

1996-01-01

We provide a summary of vegetation changes over a 11-year period (1 984-1 995) in the middle reach of the Rio Grande. Hink and Ohmart (1984) surveyed and mapped riparian vegetation along the middle Rio Grande as part of an extensive biological inventory conducted for the Army Corps of Engineers. We field-assessed and remapped the Isleta-Belen reach in 1995 to determine...

Simulating Underbelly Blast Events using Abaqus/Explicit - CEL

DTIC Science & Technology

2013-01-15

describe the material. As a result, a Langragian treatment of the structure is preferred. Therefore, a finite element solver with the capability of...algorithm is a two part process in which all material is deformed with a Lagrange treatment in a given time increment. This is followed by a remapping...accurately describe the material response of geological materials subjected to high impulse loading (i.e. shock events). The hydrostatic behavior of

Analysis of genetic diversity in pigeon pea germplasm using retrotransposon-based molecular markers.

PubMed

Maneesha; Upadhyaya, Kailash C

2017-09-01

Pigeon pea (Cajanus cajan), an important legume crop is predominantly cultivated in tropical and subtropical regions of Asia and Africa. It is normally considered to have a low degree of genetic diversity, an impediment in undertaking crop improvement programmes.We have analysed genetic polymorphism of domesticated pigeon pea germplasm (47 accessions) across the world using earlier characterized panzee retrotransposon-based molecularmarkers. Itwas conjectured that since retrotransposons are interspersed throughout the genome, retroelements-based markers would be able to uncover polymorphism possibly inherent in the diversity of retroelement sequences. Two PCR-based techniques, sequence-specific amplified polymorphism (SSAP) and retrotransposon microsatellite amplified polymorphism (REMAP) were utilized for the analyses.We show that a considerable degree of polymorphism could be detected using these techniques. Three primer combinations in SSAP generated 297 amplified products across 47 accessions with an average of 99 amplicons per assay. Degree of polymorphism varied from 84-95%. In the REMAP assays, the number of amplicons was much less but up to 73% polymorphism could be detected. On the basis of similarity coefficients, dendrograms were constructed. The results demonstrate that the retrotransposon-based markers could serve as a better alternative for the assessment of genetic diversity in crops with apparent low genetic base.

Range and Panoramic Image Fusion Into a Textured Range Image for Culture Heritage Documentation

NASA Astrophysics Data System (ADS)

Bila, Z.; Reznicek, J.; Pavelka, K.

2013-07-01

This paper deals with a fusion of range and panoramic images, where the range image is acquired by a 3D laser scanner and the panoramic image is acquired with a digital still camera mounted on a panoramic head and tripod. The fused resulting dataset, called "textured range image", provides more reliable information about the investigated object for conservators and historians, than using both datasets separately. A simple example of fusion of a range and panoramic images, both obtained in St. Francis Xavier Church in town Opařany, is given here. Firstly, we describe the process of data acquisition, then the processing of both datasets into a proper format for following fusion and the process of fusion. The process of fusion can be divided into a two main parts: transformation and remapping. In the first, transformation, part, both images are related by matching similar features detected on both images with a proper detector, which results in transformation matrix enabling transformation of the range image onto a panoramic image. Then, the range data are remapped from the range image space into a panoramic image space and stored as an additional "range" channel. The process of image fusion is validated by comparing similar features extracted on both datasets.

Sensory motor remapping of space in human–machine interfaces

PubMed Central

Mussa-Ivaldi, Ferdinando A.; Casadio, Maura; Danziger, Zachary C.; Mosier, Kristine M.; Scheidt, Robert A.

2012-01-01

Studies of adaptation to patterns of deterministic forces have revealed the ability of the motor control system to form and use predictive representations of the environment. These studies have also pointed out that adaptation to novel dynamics is aimed at preserving the trajectories of a controlled endpoint, either the hand of a subject or a transported object. We review some of these experiments and present more recent studies aimed at understanding how the motor system forms representations of the physical space in which actions take place. An extensive line of investigations in visual information processing has dealt with the issue of how the Euclidean properties of space are recovered from visual signals that do not appear to possess these properties. The same question is addressed here in the context of motor behavior and motor learning by observing how people remap hand gestures and body motions that control the state of an external device. We present some theoretical considerations and experimental evidence about the ability of the nervous system to create novel patterns of coordination that are consistent with the representation of extrapersonal space. We also discuss the perspective of endowing human–machine interfaces with learning algorithms that, combined with human learning, may facilitate the control of powered wheelchairs and other assistive devices. PMID:21741543

A proposed mechanism for rapid adaptation to spectrally distorted speech.

PubMed

Azadpour, Mahan; Balaban, Evan

2015-07-01

The mechanisms underlying perceptual adaptation to severely spectrally-distorted speech were studied by training participants to comprehend spectrally-rotated speech, which is obtained by inverting the speech spectrum. Spectral-rotation produces severe distortion confined to the spectral domain while preserving temporal trajectories. During five 1-hour training sessions, pairs of participants attempted to extract spoken messages from the spectrally-rotated speech of their training partner. Data on training-induced changes in comprehension of spectrally-rotated sentences and identification/discrimination of spectrally-rotated phonemes were used to evaluate the plausibility of three different classes of underlying perceptual mechanisms: (1) phonemic remapping (the formation of new phonemic categories that specifically incorporate spectrally-rotated acoustic information); (2) experience-dependent generation of a perceptual "inverse-transform" that compensates for spectral-rotation; and (3) changes in cue weighting (the identification of sets of acoustic cues least affected by spectral-rotation, followed by a rapid shift in perceptual emphasis to favour those cues, combined with the recruitment of the same type of "perceptual filling-in" mechanisms used to disambiguate speech-in-noise). Results exclusively support the third mechanism, which is the only one predicting that learning would specifically target temporally-dynamic cues that were transmitting phonetic information most stably in spite of spectral-distortion. No support was found for phonemic remapping or for inverse-transform generation.

Pupillographic assessment of sleepiness in sleep-deprived healthy subjects.

PubMed

Wilhelm, B; Wilhelm, H; Lüdtke, H; Streicher, P; Adler, M

1998-05-01

Spontaneous pupillary-behavior in darkness provides information about a subject's level of sleepiness. In the present work, pupil measurements in complete darkness and quiet have been recorded continuously over 11-minute period with infrared video pupillography at 25 Hz. The data have been analyzed to yield three parameters describing pupil behavior; the power of diameter variation at frequencies below 0.8 Hz (slow changes in pupil size), the pupillary unrest index, and the average pupil size. To investigate the changes of these parameters in sleep deprivation, spontaneous pupillary behavior in darkness was recorded every 2 hours in 13 healthy subjects from 19:00 to 07:00 during forced wakefulness. On each occasion, comparative subjective sleepiness was assessed with a self-rating scale (Stanford Sleepiness Scale, SSS). The power of slow pupillary oscillations (< or = 0.8 Hz) increased significantly and so did the values of SSS, while basic pupil diameter decreased significantly. Slow pupillary oscillations and SSS did not correlate well in general but high values of pupil parameters were always associated with high values in subjective rating. Our results demonstrate a strong relationship between ongoing sleep deprivation and typical changes in the frequency profiles of spontaneous pupillary oscillations and the tendency to instability in pupil size in normals. These findings suggest that the results of pupil data analysis permit an objective measurement of sleepiness.

The relationship between baseline pupil size and intelligence.

PubMed

Tsukahara, Jason S; Harrison, Tyler L; Engle, Randall W

2016-12-01

Pupil dilations of the eye are known to correspond to central cognitive processes. However, the relationship between pupil size and individual differences in cognitive ability is not as well studied. A peculiar finding that has cropped up in this research is that those high on cognitive ability have a larger pupil size, even during a passive baseline condition. Yet these findings were incidental and lacked a clear explanation. Therefore, in the present series of studies we systematically investigated whether pupil size during a passive baseline is associated with individual differences in working memory capacity and fluid intelligence. Across three studies we consistently found that baseline pupil size is, in fact, related to cognitive ability. We showed that this relationship could not be explained by differences in mental effort, and that the effect of working memory capacity and fluid intelligence on pupil size persisted even after 23 sessions and taking into account the effect of novelty or familiarity with the environment. We also accounted for potential confounding variables such as; age, ethnicity, and drug substances. Lastly, we found that it is fluid intelligence, more so than working memory capacity, which is related to baseline pupil size. In order to provide an explanation and suggestions for future research, we also consider our findings in the context of the underlying neural mechanisms involved. Copyright © 2016 Elsevier Inc. All rights reserved.

Pupil size directly modulates the feedforward response in human primary visual cortex independently of attention.

PubMed

Bombeke, Klaas; Duthoo, Wout; Mueller, Sven C; Hopf, Jens-Max; Boehler, C Nico

2016-02-15

Controversy revolves around the question of whether psychological factors like attention and emotion can influence the initial feedforward response in primary visual cortex (V1). Although traditionally, the electrophysiological correlate of this response in humans (the C1 component) has been found to be unaltered by psychological influences, a number of recent studies have described attentional and emotional modulations. Yet, research into psychological effects on the feedforward V1 response has neglected possible direct contributions of concomitant pupil-size modulations, which are known to also occur under various conditions of attentional load and emotional state. Here we tested the hypothesis that such pupil-size differences themselves directly affect the feedforward V1 response. We report data from two complementary experiments, in which we used procedures that modulate pupil size without differences in attentional load or emotion while simultaneously recording pupil-size and EEG data. Our results confirm that pupil size indeed directly influences the feedforward V1 response, showing an inverse relationship between pupil size and early V1 activity. While it is unclear in how far this effect represents a functionally-relevant adaptation, it identifies pupil-size differences as an important modulating factor of the feedforward response of V1 and could hence represent a confounding variable in research investigating the neural influence of psychological factors on early visual processing. Copyright © 2015 Elsevier Inc. All rights reserved.

[New trends in the evaluation of mathematics learning disabilities. The role of metacognition].

PubMed

Miranda-Casas, A; Acosta-Escareño, G; Tarraga-Minguez, R; Fernández, M I; Rosel-Remírez, J

2005-01-15

The current trends in the evaluation of mathematics learning disabilities (MLD), based on cognitive and empirical models, are oriented towards combining procedures involving the criteria and the evaluation of cognitive and metacognitive processes, associated to performance in mathematical tasks. The objective of this study is to analyse the metacognitive skills of prediction and evaluation in performing maths tasks and to compare metacognitive performance among pupils with MLD and younger pupils without MLD, who have the same level of mathematical performance. Likewise, we analyse these pupils' desire to learn. Subjects and methods. We compare a total of 44 pupils from the second cycle of primary education (8-10 years old) with and without mathematics learning disabilities. Significant differences are observed between pupils with and without mathematics learning disabilities in their capacity to predict and assess all of the tasks evaluated. As regards their 'desire to learn', no significant differences were found between pupils with and without MLD, which indicated that those with MLD assess their chances of successfully performing maths tasks in the same way as those without MLD. Finally, the findings reveal a similar metacognitive profile in pupils with MLD and the younger pupils with no mathematics learning disabilities. In future studies we consider it important to analyse the influence of the socio-affective belief system in the use of metacognitive skills.

What explains between-school differences in rates of smoking?

PubMed Central

Henderson, Marion; Ecob, Russell; Wight, Daniel; Abraham, Charles

2008-01-01

Background Schools have the potential to influence their pupils' behaviour through the school's social organisation and culture (non-formal school characteristics), as well as through the formal curriculum. This paper examines whether these school characteristics (which include a measure of quality of social relationships) can account for school differences in smoking rates. Methods This study uses a longitudinal survey involving 5,092 pupils in 24 Scottish schools. Pupils' smoking (at age 15/16), cognitive measures, attitude to school and pupils' rating of teacher pupil relationships (at age 13/14) were linked to school level data comprising teacher assessed quality of pupil-staff relationships, school level deprivation, staying on rates and attendance. Analysis involved multi-level modelling. Results Overall, 25% of males and 39% of females reported smoking, with rates by school ranging from 8% to 33% for males and from 28% to 49% for females. When individual socio-economic and socio-cultural factors were controlled for there was still a large school effect for males and a smaller (but correlated) school effect for females at 15/16 years. For girls their school effect was explained by their rating of teacher-pupil relationships and attitude to school. These variables were also significant in predicting smoking among boys. However, the school effect for boys was most radically attenuated and became insignificant when the interaction between poor quality of teacher – pupil relationships and school level affluence was fitted, explaining 82% of the variance between schools. In addition, researchers' rating of the schools' focus on caring and inclusiveness was also significantly associated with both male and female smoking rates. Conclusion School-level characteristics have an impact on male and female pupils' rates of smoking up to 15/16 years of age. The size of the school effect is greater for males at this age. The social environment of schools, in particular the quality of teacher-pupil relationships, pupils' attitude to school and the school's focus on caring and inclusiveness, can influence both boys' and girls' smoking. This provides support for the school-wide or "Health Promoting School" approach to smoking prevention. PMID:18570635

Interaction of aberrations, diffraction, and quantal fluctuations determine the impact of pupil size on visual quality.

PubMed

Xu, Renfeng; Wang, Huachun; Thibos, Larry N; Bradley, Arthur

2017-04-01

Our purpose is to develop a computational approach that jointly assesses the impact of stimulus luminance and pupil size on visual quality. We compared traditional optical measures of image quality and those that incorporate the impact of retinal illuminance dependent neural contrast sensitivity. Visually weighted image quality was calculated for a presbyopic model eye with representative levels of chromatic and monochromatic aberrations as pupil diameter was varied from 7 to 1 mm, stimulus luminance varied from 2000 to 0.1  cd/m², and defocus varied from 0 to -2 diopters. The model included the effects of quantal fluctuations on neural contrast sensitivity. We tested the model's predictions for five cycles per degree gratings by measuring contrast sensitivity at 5  cyc/deg. Unlike the traditional Strehl ratio and the visually weighted area under the modulation transfer function, the visual Strehl ratio derived from the optical transfer function was able to capture the combined impact of optics and quantal noise on visual quality. In a well-focused eye, provided retinal illuminance is held constant as pupil size varies, visual image quality scales approximately as the square root of illuminance because of quantum fluctuations, but optimum pupil size is essentially independent of retinal illuminance and quantum fluctuations. Conversely, when stimulus luminance is held constant (and therefore illuminance varies with pupil size), optimum pupil size increases as luminance decreases, thereby compensating partially for increased quantum fluctuations. However, in the presence of -1 and -2 diopters of defocus and at high photopic levels where Weber's law operates, optical aberrations and diffraction dominate image quality and pupil optimization. Similar behavior was observed in human observers viewing sinusoidal gratings. Optimum pupil size increases as stimulus luminance drops for the well-focused eye, and the benefits of small pupils for improving defocused image quality remain throughout the photopic and mesopic ranges. However, restricting pupils to <2  mm will cause significant reductions in the best focus vision at low photopic and mesopic luminances.

Cost-Effective Magnetoencephalography Based on Time Encoded Optical Fiber Interferometry for Epilepsy and Tinnitus

DTIC Science & Technology

2016-09-01

Thanks to the elegant reciprocal geometry of the Sagnac interferometer, many sources of drift that would present in other polarimetry techniques were...interferometers. And is 2 orders of magnitude better than competing polarimetry -based Faraday techniques. Couple a Rb Vapor cell to the Sagnac interferometer

Imaging interferometer using dual broadband quantum well infrared photodetectors

NASA Technical Reports Server (NTRS)

Reininger, F.; Gunapala, S.; Bandara, S.; Grimm, M.; Johnson, D.; Peters, D.; Leland, S.; Liu, J.; Mumolo, J.; Rafol, D.;

Two-Particle Four-Mode Interferometer for Atoms

NASA Astrophysics Data System (ADS)

Dussarrat, Pierre; Perrier, Maxime; Imanaliev, Almazbek; Lopes, Raphael; Aspect, Alain; Cheneau, Marc; Boiron, Denis; Westbrook, Christoph I.

2017-10-01

We present a free-space interferometer to observe two-particle interference of a pair of atoms with entangled momenta. The source of atom pairs is a Bose-Einstein condensate subject to a dynamical instability, and the interferometer is realized using Bragg diffraction on optical lattices, in the spirit of our recent Hong-Ou-Mandel experiment. We report on an observation ruling out the possibility of a purely mixed state at the input of the interferometer. We explain how our current setup can be extended to enable a test of a Bell inequality on momentum observables.

Fourier-transform and global contrast interferometer alignment methods

DOEpatents

Goldberg, Kenneth A.

2001-01-01

Interferometric methods are presented to facilitate alignment of image-plane components within an interferometer and for the magnified viewing of interferometer masks in situ. Fourier-transforms are performed on intensity patterns that are detected with the interferometer and are used to calculate pseudo-images of the electric field in the image plane of the test optic where the critical alignment of various components is being performed. Fine alignment is aided by the introduction and optimization of a global contrast parameter that is easily calculated from the Fourier-transform.

SUNLITE program. Sub-Hertz relative frequency stabilization of two diode laser pumped Nd:YAG lasers locked to a Fabry-Perot interferometer

NASA Technical Reports Server (NTRS)

Byer, R. L.

1990-01-01

Two laser pumped Nd:YAG lasers were frequency stabilized to a commercial 6.327 GHz free spectral range Fabry-Perot interferometer yielding a best case beatnote linewidth of 330 MHz. In addition, a Fabry-Perot interferometer with a free spectral range of 680 MHz, a linewidth of 25 kHz, and a finesse of 27,500 was built, and when it was substituted in place of the commercial interferometer, it produced a robust and easily repeatable beatnote linewidth of 700 MHz.