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Sample records for binocular rivalry reveals

  1. Can binocular rivalry reveal neural correlates of consciousness?

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    Blake, Randolph; Brascamp, Jan; Heeger, David J.

    2014-01-01

    This essay critically examines the extent to which binocular rivalry can provide important clues about the neural correlates of conscious visual perception. Our ideas are presented within the framework of four questions about the use of rivalry for this purpose: (i) what constitutes an adequate comp

  2. Neurons that detect interocular conflict during binocular rivalry revealed with EEG.

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    Katyal, Sucharit; Engel, Stephen A; He, Bin; He, Sheng

    2016-01-01

    When the two eyes view incompatible images, perception alternates between them. What neural computations underlie this binocular rivalry? Perceptual alternations may simply reflect competition between the sets of monocular neurons that respond to each image, with the stronger driving perception. Here, we test an alternative hypothesis, that the computations that resolve rivalry make use of an active signal that reflects interocular conflict. Images presented to each eye were flickered at different frequencies while we measured steady-state visually evoked potentials (SSVEP). Signals at frequencies that are combinations of the two input frequencies can arise only from binocular neurons. In a first experiment, we measured energy at these "intermodulation" frequencies during binocular rivalry and found it to be highest immediately before rivalry restarted following a period of incomplete resolution of rivalry (a "mixed" percept). This suggests that the intermodulation signals may arise from neurons important for resolving the conflict between the two eyes' inputs. In a second experiment, we tested whether the intermodulation signal arose from neurons that measure interocular conflict by parametrically increasing conflict while simultaneously reducing image contrast. The activity of neurons that receive input from both eyes but are not sensitive to conflict should reduce monotonically as contrast decreases. The intermodulation response, however, peaked at intermediate levels of conflict, suggesting that it arises in part from neurons that respond to interocular conflict. Binocular rivalry appears to depend on an active mechanism that detects interocular conflict, whose levels of activity can be measured by the intermodulation frequencies of the SSVEP.

  3. High level binocular rivalry effects

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    Michal eWolf

    2011-12-01

    Full Text Available Binocular rivalry (BR occurs when the brain cannot fuse percepts from the two eyes because they are different. We review results relating to an ongoing controversy regarding the cortical site of the BR mechanism. Some BR qualities suggest it is low-level: 1 BR, as its name implies, is usually between eyes and only low levels have access to utrocular information. 2 All input to one eye is suppressed: blurring doesn’t stimulate accommodation; pupilary constrictions are reduced; probe detection is reduced. 3 Rivalry is affected by low level attributes, contrast, spatial frequency, brightness, motion. 4 There is limited priming due to suppressed words or pictures. On the other hand, recent studies favor a high level mechanism: 1 Rivalry occurs between patterns, not eyes, as in patchwork rivalry or a swapping paradigm. 2 Attention affects alternations. 3 Context affects dominance. There is conflicting evidence from physiological studies (single cell and fMRI regarding cortical level(s of conscious perception. We discuss the possibility of multiple BR sites and theoretical considerations that rule out this solution.We present new data regarding the locus of the BR switch by manipulating stimulus semantic content or high-level characteristics. Since these variations are represented at higher cortical levels, their affecting rivalry supports high-level BR intervention. In Experiment I, we measure rivalry when one eye views words and the other nonwords and find significantly longer dominance durations for nonwords. In Experiment II, we find longer dominance times for line drawings of simple, structurally impossible figures than for similar, possible objects. In Experiment III, we test the influence of idiomatic context on rivalry between words. Results show that generally words within their idiomatic context have longer mean dominance durations. We conclude that Binocular Rivalry has high-level cortical influences, and may be controlled by a high

  4. Interactions between binocular rivalry and Gestalt formation

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    Weert, C.M.M. de; Snoeren, P.R.; Koning, A.R.

    2005-01-01

    A question raised a long time ago in binocular rivalry research is whether the phenomenon of binocular rivalry is purely determined by local stimulus properties or that global stimulus properties also play a role. More specifically: do coherent features in a stimulus influence rivalrous behavior? Af

  5. Rhythms of consciousness: binocular rivalry reveals large-scale oscillatory network dynamics mediating visual perception.

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    Sam M Doesburg

    Full Text Available Consciousness has been proposed to emerge from functionally integrated large-scale ensembles of gamma-synchronous neural populations that form and dissolve at a frequency in the theta band. We propose that discrete moments of perceptual experience are implemented by transient gamma-band synchronization of relevant cortical regions, and that disintegration and reintegration of these assemblies is time-locked to ongoing theta oscillations. In support of this hypothesis we provide evidence that (1 perceptual switching during binocular rivalry is time-locked to gamma-band synchronizations which recur at a theta rate, indicating that the onset of new conscious percepts coincides with the emergence of a new gamma-synchronous assembly that is locked to an ongoing theta rhythm; (2 localization of the generators of these gamma rhythms reveals recurrent prefrontal and parietal sources; (3 theta modulation of gamma-band synchronization is observed between and within the activated brain regions. These results suggest that ongoing theta-modulated-gamma mechanisms periodically reintegrate a large-scale prefrontal-parietal network critical for perceptual experience. Moreover, activation and network inclusion of inferior temporal cortex and motor cortex uniquely occurs on the cycle immediately preceding responses signaling perceptual switching. This suggests that the essential prefrontal-parietal oscillatory network is expanded to include additional cortical regions relevant to tasks and perceptions furnishing consciousness at that moment, in this case image processing and response initiation, and that these activations occur within a time frame consistent with the notion that conscious processes directly affect behaviour.

  6. Insights from intermittent binocular rivalry and EEG

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    Michael A Pitts

    2011-09-01

    Full Text Available Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical approaches, including EEG microstates, event-related potentials, and statistically-based source estimation, and propose a spatio-temporal model that integrates findings from several studies. Finally, we discuss the advantages and limitations of using binocular rivalry as a tool to investigate the neural basis of perceptual awareness.

  7. Emotion and Interhemispheric Interactions in Binocular Rivalry

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    K L Ritchie

    2013-10-01

    Full Text Available Previous research has shown that fear-related stimuli presented in peripheral vision are preferentially processed over stimuli depicting other emotions. Furthermore, emotional content can influence dominance duration in binocular rivalry, with the period of dominance for an emotional image (e.g. a fearful face being significantly longer than a neutral image (e.g. a neutral face or a house. Experiment 1 of the current study combined these two ideas to investigate the role of emotion in binocular rivalry with face/house pairs viewed in the periphery. The results showed that faces were perceived as more dominant than houses, and fearful faces more so than neutral faces, even when viewed in the periphery. Experiment 2 extended this paradigm to present a rival pair in the periphery in each hemifield, with each eye either viewing the same stimulus in each location (traditional condition, or a different stimulus in each location (Diaz-Caneja condition. The results showed that the two pairs tended to rival in synchrony only in the traditional condition. Taken together, the results show that face dominance and emotion dominance in binocular rivalry persist in the periphery, and that interhemispheric interactions in binocular rivalry depend on an eye- as opposed to an object-based mechanism.

  8. Quantum formalism to describe binocular rivalry.

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    Manousakis, Efstratios

    2009-11-01

    On the basis of the general character and operation of the process of perception, a formalism is sought to mathematically describe the subjective or abstract/mental process of perception. It is shown that the formalism of orthodox quantum theory of measurement, where the observer plays a key role, is a broader mathematical foundation which can be adopted to describe the dynamics of the subjective experience. The mathematical formalism describes the psychophysical dynamics of the subjective or cognitive experience as communicated to us by the subject. Subsequently, the formalism is used to describe simple perception processes and, in particular, to describe the probability distribution of dominance duration obtained from the testimony of subjects experiencing binocular rivalry. Using this theory and parameters based on known values of neuronal oscillation frequencies and firing rates, the calculated probability distribution of dominance duration of rival states in binocular rivalry under various conditions is found to be in good agreement with available experimental data. This theory naturally explains an observed marked increase in dominance duration in binocular rivalry upon periodic interruption of stimulus and yields testable predictions for the distribution of perceptual alteration in time.

  9. On the role of attention in binocular rivalry: electrophysiological evidence.

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    Urte Roeber

    Full Text Available During binocular rivalry visual consciousness fluctuates between two dissimilar monocular images. We investigated the role of attention in this phenomenon by comparing event-related potentials (ERPs when binocular-rivalry stimuli were attended with when they were unattended. Stimuli were dichoptic, orthogonal gratings that yielded binocular rivalry and dioptic, identically oriented gratings that yielded binocular fusion. Events were all possible orthogonal changes in orientation of one or both gratings. We had two attention conditions: In the attend-to-grating condition, participants had to report changes in perceived orientation, focussing their attention on the gratings. In the attend-to-fixation condition participants had to report changes in a central fixation target, taking attention away from the gratings. We found, surprisingly, that attending to rival gratings yielded a smaller ERP component (the N1, from 160-210 ms than attending to the fixation target. To explain this paradoxical effect of attention, we propose that rivalry occurs in the attend-to-fixation condition (we found an ERP signature of rivalry in the form of a sustained negativity from 210-300 ms but that the mechanism processing the stimulus changes is more adapted in the attend-to-grating condition than in the attend-to-fixation condition. This is consistent with the theory that adaptation gives rise to changes of visual consciousness during binocular rivalry.

  10. Binocular rivalry: a window into emotional processing in aging.

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    Bannerman, Rachel L; Regener, Paula; Sahraie, Arash

    2011-06-01

    Previous binocular rivalry studies with younger adults have shown that emotional stimuli dominate perception over neutral stimuli. Here we investigated the effects of age on patterns of emotional dominance during binocular rivalry. Participants performed a face/house rivalry task where the emotion of the face (happy, angry, neutral) and orientation (upright, inverted) of the face and house stimuli were varied systematically. Age differences were found with younger adults showing a general emotionality effect (happy and angry faces were more dominant than neutral faces) and older adults showing inhibition of anger (neutral faces were more dominant than angry faces) and positivity effects (happy faces were more dominant than both angry and neutral faces). Age differences in dominance patterns were reflected by slower rivalry rates for both happy and angry compared to neutral face/house pairs in younger adults, and slower rivalry rates for happy compared to both angry and neutral face/house pairs in older adults. Importantly, these patterns of emotional dominance and slower rivalry rates for emotional-face/house pairs disappeared when the stimuli were inverted. This suggests that emotional valence, and not low-level image features, were responsible for the emotional bias in both age groups. Given that binocular rivalry has a limited role for voluntary control, the findings imply that anger suppression and positivity effects in older adults may extend to more automatic tasks.

  11. When crowding meets binocular rivalry: challenges for object perception.

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    Kim, Sangrae; Shin, Eunsam; Chong, Sang Chul

    2013-01-14

    Both crowding and binocular rivalry impair object perception, but their influence on object perception has so far only been investigated in separate fields. Three experiments investigated the joint influences of crowding and rivalry on object perception (orientation discrimination). Experiment 1 investigated how crowding and rivalry influence orientation discrimination together. Experiment 2 tested whether rivalry between flankers affects crowding using an orientation discrimination task. Experiment 3 tested whether crowding affects the temporal dynamics of the rivalry between a target and a rival stimulus. In Experiment 1, judgments of target orientation were more impaired when crowding and rivalry were simultaneously induced than when they were separately induced and their effects were combined. In Experiment 2, judgments of target orientation were impaired even when flankers were undergoing rivalry, thus highlighting the importance of the presence of flankers. Experiment 3 showed that flankers presented in the neighborhood of a target undergoing rivalry shortened target dominance and prolonged target suppression. The augmented impairments of object perception found in Experiments 1 and 3 suggest that crowding and rivalry interact, presumably through signal suppression. The adverse effect of flankers shown in Experiment 2 suggests that inappropriate feature integration may have additionally contributed to this interaction.

  12. Predictive context influences perceptual selection during binocular rivalry

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    Rachel N Denison

    2011-12-01

    Full Text Available Prediction may be a fundamental principle of sensory processing: it has been proposed that the brain continuously generates predictions about forthcoming sensory information. However, little is known about how prediction contributes to the selection of a conscious percept from among competing alternatives. Here, we used binocular rivalry to investigate the effects of prediction on perceptual selection. In binocular rivalry, incompatible images presented to the two eyes result in a perceptual alternation between the images, even though the visual stimuli remain constant. If predictive signals influence the competition between neural representations of rivalrous images, this influence should generate a bias in perceptual selection that depends on predictive context. To manipulate predictive context, we developed a novel binocular rivalry paradigm in which rivalrous test images were immediately preceded by a sequence of context images presented identically to the two eyes. One of the test images was consistent with the preceding image sequence (it was the expected next image in the series, and the other was inconsistent (non-predicted. We found that human observers were more likely to perceive the consistent image at the onset of rivalry, suggesting that predictive context biased selection in favor of the predicted percept. This prediction effect was distinct from the effects of adaptation to stimuli presented before the binocular rivalry test. In addition, perceptual reports were speeded for predicted percepts relative to non-predicted percepts. These results suggest that predictive signals related to visual stimulus history exist at neural sites that can bias conscious perception during binocular rivalry. Our paradigm provides a new way to study how prior information and incoming sensory information combine to generate visual percepts.

  13. Symbolic Magnitude Modulates Perceptual Strength in Binocular Rivalry

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    Paffen, Chris L. E.; Plukaard, Sarah; Kanai, Ryota

    2011-01-01

    Basic aspects of magnitude (such as luminance contrast) are directly represented by sensory representations in early visual areas. However, it is unclear how symbolic magnitudes (such as Arabic numerals) are represented in the brain. Here we show that symbolic magnitude affects binocular rivalry: perceptual dominance of numbers and objects of…

  14. Binocular rivalry alternations and their relation to visual adaptation

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    Daphne eRoumani

    2012-03-01

    Full Text Available When different stimuli are presented dichoptically, perception alternates between the two in a stochastic manner. After a long-lasting and rigorous debate, there is growing consensus that this phenomenon, known as binocular rivalry, is the result of a dynamic competition occurring at multiple levels of the visual hierarchy. The role of low- and high-level adaptation mechanisms in controlling these perceptual alternations has been a key issue in the rivalry literature. Both types of adaptation are dispersed throughout the visual system and have an equally influential, or even causal, role in determining perception. Such an explanation of binocular rivalry is also in accordance with the relationship between the latter and attention. However, an overall explanation of this intriguing perceptual phenomenon needs to also include noise as an equally fundamental process involved in the stochastic resonance of perceptual bistability.

  15. Binocular Rivalry in a Competitive Neural Network with Synaptic Depression

    KAUST Repository

    Kilpatrick, Zachary P.

    2010-01-01

    We study binocular rivalry in a competitive neural network with synaptic depression. In particular, we consider two coupled hypercolums within primary visual cortex (V1), representing orientation selective cells responding to either left or right eye inputs. Coupling between hypercolumns is dominated by inhibition, especially for neurons with dissimilar orientation preferences. Within hypercolumns, recurrent connectivity is excitatory for similar orientations and inhibitory for different orientations. All synaptic connections are modifiable by local synaptic depression. When the hypercolumns are driven by orthogonal oriented stimuli, it is possible to induce oscillations that are representative of binocular rivalry. We first analyze the occurrence of oscillations in a space-clamped version of the model using a fast-slow analys is, taking advantage of the fact that depression evolves much slower than population activity. We th en analyze the onset of oscillations in the full spatially extended system by carrying out a piecewise smooth stability analysis of single (winner-take-all) and double (fusion) bumps within the network. Although our stability analysis takes into account only instabilities associated with real eigenvalues, it identifies points of instability that are consistent with what is found numerically. In particular, we show that, in regions of parameter space where double bumps are unstable and no single bumps exist, binocular rivalry can arise as a slow alternation between either population supporting a bump. © 2010 Society for Industrial and Applied Mathematics.

  16. Stimulus motion propels traveling waves in binocular rivalry.

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    Tomas Knapen

    Full Text Available State transitions in the nervous system often take shape as traveling waves, whereby one neural state is replaced by another across space in a wave-like manner. In visual perception, transitions between the two mutually exclusive percepts that alternate when the two eyes view conflicting stimuli (binocular rivalry may also take shape as traveling waves. The properties of these waves point to a neural substrate of binocular rivalry alternations that have the hallmark signs of lower cortical areas. In a series of experiments, we show a potent interaction between traveling waves in binocular rivalry and stimulus motion. The course of the traveling wave is biased in the motion direction of the suppressed stimulus that gains dominance by means of the wave-like transition. Thus, stimulus motion may propel the traveling wave across the stimulus to the extent that the stimulus motion dictates the traveling wave's direction completely. Using a computational model, we show that a speed-dependent asymmetry in lateral inhibitory connections between retinotopically organized and motion-sensitive neurons can explain our results. We argue that such a change in suppressive connections may play a vital role in the resolution of dynamic occlusion situations.

  17. Natural Tendency towards Beauty in Humans: Evidence from Binocular Rivalry.

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    Ce Mo

    Full Text Available Although human preference for beauty is common and compelling in daily life, it remains unknown whether such preference is essentially subserved by social cognitive demands or natural tendency towards beauty encoded in the human mind intrinsically. Here we demonstrate experimentally that humans automatically exhibit preference for visual and moral beauty without explicit cognitive efforts. Using a binocular rivalry paradigm, we identified enhanced gender-independent perceptual dominance for physically attractive persons, and the results suggested universal preference for visual beauty based on perceivable forms. Moreover, we also identified perceptual dominance enhancement for characters associated with virtuous descriptions after controlling for facial attractiveness and vigilance-related attention effects, which suggested a similar implicit preference for moral beauty conveyed in prosocial behaviours. Our findings show that behavioural preference for beauty is driven by an inherent natural tendency towards beauty in humans rather than explicit social cognitive processes.

  18. Natural Tendency towards Beauty in Humans: Evidence from Binocular Rivalry.

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    Mo, Ce; Xia, Tiansheng; Qin, Kaixin; Mo, Lei

    2016-01-01

    Although human preference for beauty is common and compelling in daily life, it remains unknown whether such preference is essentially subserved by social cognitive demands or natural tendency towards beauty encoded in the human mind intrinsically. Here we demonstrate experimentally that humans automatically exhibit preference for visual and moral beauty without explicit cognitive efforts. Using a binocular rivalry paradigm, we identified enhanced gender-independent perceptual dominance for physically attractive persons, and the results suggested universal preference for visual beauty based on perceivable forms. Moreover, we also identified perceptual dominance enhancement for characters associated with virtuous descriptions after controlling for facial attractiveness and vigilance-related attention effects, which suggested a similar implicit preference for moral beauty conveyed in prosocial behaviours. Our findings show that behavioural preference for beauty is driven by an inherent natural tendency towards beauty in humans rather than explicit social cognitive processes.

  19. Effects of the Amazonian psychoactive beverage Ayahuasca on binocular rivalry: interhemispheric switching or interhemispheric fusion?

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    Frecska, Ede; White, Keith D; Luna, Luis E

    2003-01-01

    An early theoretical analysis supposed changes in hemispheric integration as the basis of altered state of consciousness induced by psychoactive drugs. Brain imaging studies revealed right cortical activation after administration of hallucinogens. Recent studies on binocular rivalry suggest that interhemispheric switching is the neural substrate of the perceptual oscillations observed during dichoptic stimulus presentation. The current study tested perceptual alternation in ceremonial participants, who ingested the South American hallucinogenic beverage ayahuasca, to examine the claim that there might be changes in interhemispheric function under the influence of hallucinogens. Ingestion of ayahuasca resulted in a decrease of rivalry alternation rates, increased length of one percept and there was evidence of phenomenal fusion. The findings are in line with results of brain activation studies and support the concept of interhemispheric fusion in altered states of consciousness.

  20. Binocular rivalry waves in a directionally selective neural field model

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    Carroll, Samuel R.; Bressloff, Paul C.

    2014-10-01

    We extend a neural field model of binocular rivalry waves in the visual cortex to incorporate direction selectivity of moving stimuli. For each eye, we consider a one-dimensional network of neurons that respond maximally to a fixed orientation and speed of a grating stimulus. Recurrent connections within each one-dimensional network are taken to be excitatory and asymmetric, where the asymmetry captures the direction and speed of the moving stimuli. Connections between the two networks are taken to be inhibitory (cross-inhibition). As per previous studies, we incorporate slow adaption as a symmetry breaking mechanism that allows waves to propagate. We derive an analytical expression for traveling wave solutions of the neural field equations, as well as an implicit equation for the wave speed as a function of neurophysiological parameters, and analyze their stability. Most importantly, we show that propagation of traveling waves is faster in the direction of stimulus motion than against it, which is in agreement with previous experimental and computational studies.

  1. Stereopsis and binocular rivalry are based on perceived rather than physical orientations.

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    Chopin, Adrien; Mamassian, Pascal; Blake, Randolph

    2012-06-15

    Binocular rivalry is an intriguing phenomenon: when different images are displayed to the two eyes, perception alternates between these two images. What determines whether two monocular images engage in fusion or in rivalry: the physical difference between these images or the difference between the percepts resulting from the images? We investigated that question by measuring the interocular difference of grid orientation needed to produce a transition from fusion to rivalry and by changing those transitions by means of a superimposed tilt illusion. Fusion was attested by a correct stereoscopic slant perception of the grid. The superimposed tilt illusion was achieved in displaying small segments on the grids. We found that the illusion can change the fusion-rivalry transitions indicating that rivalry and fusion are based on the perceived orientations rather than the displayed ones. In a second experiment, we confirmed that the absence of binocular rivalry resulted in fusion and stereoscopic slant perception. We conclude that the superimposed tilt illusion arises at a level of visual processing prior to those stages mediating binocular rivalry and stereoscopic depth extraction.

  2. How Simultaneous is the Perception of Binocular Depth and Rivalry in Plaid Stimuli?

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    Athena Buckthought

    2012-06-01

    Full Text Available Psychophysical experiments have demonstrated that it is possible to perceive both binocular depth and rivalry in plaids (Buckthought and Wilson 2007, Vision Research 47 2543–2556. In a recent study, we investigated the neural substrates for depth and rivalry processing with these plaid patterns, when either a depth or rivalry task was performed (Buckthought and Mendola 2011, Journal of Vision 11 1–15. However, the extent to which perception of the two stimulus aspects was truly simultaneous remained somewhat unclear. In the present study, we introduced a new task in which subjects were instructed to perform both depth and rivalry tasks concurrently. Subjects were clearly able to perform both tasks at the same time, but with a modest, symmetric drop in performance when compared to either task carried out alone. Subjects were also able to raise performance levels for either task by performing it with a higher priority, with a decline in performance for the other task. The symmetric declines in performance are consistent with the interpretation that the two tasks are equally demanding of attention (Braun and Julesz 1998, Perception & Psychophysics 60 1–23. The results demonstrate the impressive combination of binocular features that supports coincident depth and rivalry in surface perception, within the constraints of presumed orientation and spatial frequency channels.

  3. Dichoptic viewing methods for binocular rivalry research: prospects for large-scale clinical and genetic studies.

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    Law, Phillip C F; Paton, Bryan K; Thomson, Richard H; Liu, Guang B; Miller, Steven M; Ngo, Trung T

    2013-12-01

    Binocular rivalry (BR) is an intriguing phenomenon that occurs when two different images are presented, one to each eye, resulting in alternation or rivalry between the percepts. The phenomenon has been studied for nearly 200 years, with renewed and intensive investigation over recent decades. The rate of perceptual switching has long been known to vary widely between individuals but to be relatively stable within individuals. A recent twin study demonstrated that individual variation in BR rate is under substantial genetic control, a finding that also represented the first report, using a large study, of genetic contribution for any post-retinal visual processing phenomenon. The twin study had been prompted by earlier work showing BR rate was slow in the heritable psychiatric condition, bipolar disorder (BD). Together, these studies suggested that slow BR may represent an endophenotype for BD, and heralded the advent of modern clinical and genetic studies of rivalry. This new focus has coincided with rapid advances in 3D display technology, but despite such progress, specific development of technology for rivalry research has been lacking. This review therefore compares different display methods for BR research across several factors, including viewing parameters, image quality, equipment cost, compatibility with other investigative methods, subject group, and sample size, with a focus on requirements specific to large-scale clinical and genetic studies. It is intended to be a resource for investigators new to BR research, such as clinicians and geneticists, and to stimulate the development of 3D display technology for advancing interdisciplinary studies of rivalry.

  4. A neural network approach to fMRI binocular visual rivalry task analysis.

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    Nicola Bertolino

    Full Text Available The purpose of this study was to investigate whether artificial neural networks (ANN are able to decode participants' conscious experience perception from brain activity alone, using complex and ecological stimuli. To reach the aim we conducted pattern recognition data analysis on fMRI data acquired during the execution of a binocular visual rivalry paradigm (BR. Twelve healthy participants were submitted to fMRI during the execution of a binocular non-rivalry (BNR and a BR paradigm in which two classes of stimuli (faces and houses were presented. During the binocular rivalry paradigm, behavioral responses related to the switching between consciously perceived stimuli were also collected. First, we used the BNR paradigm as a functional localizer to identify the brain areas involved the processing of the stimuli. Second, we trained the ANN on the BNR fMRI data restricted to these regions of interest. Third, we applied the trained ANN to the BR data as a 'brain reading' tool to discriminate the pattern of neural activity between the two stimuli. Fourth, we verified the consistency of the ANN outputs with the collected behavioral indicators of which stimulus was consciously perceived by the participants. Our main results showed that the trained ANN was able to generalize across the two different tasks (i.e. BNR and BR and to identify with high accuracy the cognitive state of the participants (i.e. which stimulus was consciously perceived during the BR condition. The behavioral response, employed as control parameter, was compared with the network output and a statistically significant percentage of correspondences (p-value <0.05 were obtained for all subjects. In conclusion the present study provides a method based on multivariate pattern analysis to investigate the neural basis of visual consciousness during the BR phenomenon when behavioral indicators lack or are inconsistent, like in disorders of consciousness or sedated patients.

  5. The impact of stimulus complexity and frequency swapping on stabilization of binocular rivalry

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    Sandberg, Kristian; Bahrami, B; Lindeløv, Jonas Kristoffer;

    2011-01-01

    high-level perceptual content. We conclude that overlaps at low visual stages are the most likely cause of the eye-specific stabilization for both stimulus types. Additionally, we examined the impact of swapping the flicker frequency of the images and found a general impact on stabilization......Binocular rivalry occurs when an image is presented to one eye while at the same time another, incongruent, image is presented to the other eye in the corresponding retinotopic location and conscious perception alternates spontaneously between the two monocular views. If a short blank period...... is inserted between intermittent presentations of rivaling stimuli, perception is stabilized and spontaneous alternations are drastically reduced. Whether the complexity of rivaling stimuli plays a role in stabilization is unknown. We replicated previous findings that swapping the stimuli between eyes across...

  6. Perceptual reversals during binocular rivalry: ERP components and their concomitant source differences.

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    Britz, Juliane; Pitts, Michael A

    2011-11-01

    We used an intermittent stimulus presentation to investigate event-related potential (ERP) components associated with perceptual reversals during binocular rivalry. The combination of spatiotemporal ERP analysis with source imaging and statistical parametric mapping of the concomitant source differences yielded differences in three time windows: reversals showed increased activity in early visual (∼120 ms) and in inferior frontal and anterior temporal areas (∼400-600 ms) and decreased activity in the ventral stream (∼250-350 ms). The combination of source imaging and statistical parametric mapping suggests that these differences were due to differences in generator strength and not generator configuration, unlike the initiation of reversals in right inferior parietal areas. These results are discussed within the context of the extensive network of brain areas that has been implicated in the initiation, implementation, and appraisal of bistable perceptual reversals.

  7. Reinforcement of perceptual inference: reward and punishment alter conscious visual perception during binocular rivalry

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    Gregor eWilbertz

    2014-12-01

    Full Text Available Perception is an inferential process, which becomes immediately evident when sensory information is conflicting or ambiguous and thus allows for more than one perceptual interpretation. Thinking the idea of perception as inference through to the end results in a blurring of boundaries between perception and action selection, as perceptual inference implies the construction of a percept as an active process. Here we therefore wondered whether perception shares a key characteristic of action selection, namely that it is shaped by reinforcement learning. In two behavioral experiments, we used binocular rivalry to examine whether perceptual inference can be influenced by the association of perceptual outcomes with reward or punishment, respectively, in analogy to instrumental conditioning. Binocular rivalry was evoked by two orthogonal grating stimuli presented to the two eyes, resulting in perceptual alternations between the two gratings. Perception was tracked indirectly and objectively through a target detection task, which allowed us to preclude potential reporting biases. Monetary rewards or punishments were given repeatedly during perception of only one of the two rivalling stimuli. We found an increase in dominance durations for the percept associated with reward, relative to the non-rewarded percept. In contrast, punishment led to an increase of the non-punished compared to a relative decrease of the punished percept. Our results show that perception shares key characteristics with action selection, in that it is influenced by reward and punishment in opposite directions, thus narrowing the gap between the conceptually separated domains of perception and action selection. We conclude that perceptual inference is an adaptive process that is shaped by its consequences.

  8. The effects of noise on binocular rivalry waves: a stochastic neural field model

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    Webber, Matthew A.; Bressloff, Paul C.

    2013-03-01

    We analyze the effects of extrinsic noise on traveling waves of visual perception in a competitive neural field model of binocular rivalry. The model consists of two one-dimensional excitatory neural fields, whose activity variables represent the responses to left-eye and right-eye stimuli, respectively. The two networks mutually inhibit each other, and slow adaptation is incorporated into the model by taking the network connections to exhibit synaptic depression. We first show how, in the absence of any noise, the system supports a propagating composite wave consisting of an invading activity front in one network co-moving with a retreating front in the other network. Using a separation of time scales and perturbation methods previously developed for stochastic reaction-diffusion equations, we then show how extrinsic noise in the activity variables leads to a diffusive-like displacement (wandering) of the composite wave from its uniformly translating position at long time scales, and fluctuations in the wave profile around its instantaneous position at short time scales. We use our analysis to calculate the first-passage-time distribution for a stochastic rivalry wave to travel a fixed distance, which we find to be given by an inverse Gaussian. Finally, we investigate the effects of noise in the depression variables, which under an adiabatic approximation lead to quenched disorder in the neural fields during propagation of a wave.

  9. The effects of noise on binocular rivalry waves: a stochastic neural field model

    KAUST Repository

    Webber, Matthew A

    2013-03-12

    We analyze the effects of extrinsic noise on traveling waves of visual perception in a competitive neural field model of binocular rivalry. The model consists of two one-dimensional excitatory neural fields, whose activity variables represent the responses to left-eye and right-eye stimuli, respectively. The two networks mutually inhibit each other, and slow adaptation is incorporated into the model by taking the network connections to exhibit synaptic depression. We first show how, in the absence of any noise, the system supports a propagating composite wave consisting of an invading activity front in one network co-moving with a retreating front in the other network. Using a separation of time scales and perturbation methods previously developed for stochastic reaction-diffusion equations, we then show how extrinsic noise in the activity variables leads to a diffusive-like displacement (wandering) of the composite wave from its uniformly translating position at long time scales, and fluctuations in the wave profile around its instantaneous position at short time scales. We use our analysis to calculate the first-passage-time distribution for a stochastic rivalry wave to travel a fixed distance, which we find to be given by an inverse Gaussian. Finally, we investigate the effects of noise in the depression variables, which under an adiabatic approximation lead to quenched disorder in the neural fields during propagation of a wave. © 2013 IOP Publishing Ltd and SISSA Medialab srl.

  10. Perceptual rivalry: reflexes reveal the gradual nature of visual awareness.

    Directory of Open Access Journals (Sweden)

    Marnix Naber

    Full Text Available Rivalry is a common tool to probe visual awareness: a constant physical stimulus evokes multiple, distinct perceptual interpretations ("percepts" that alternate over time. Percepts are typically described as mutually exclusive, suggesting that a discrete (all-or-none process underlies changes in visual awareness. Here we follow two strategies to address whether rivalry is an all-or-none process: first, we introduce two reflexes as objective measures of rivalry, pupil dilation and optokinetic nystagmus (OKN; second, we use a continuous input device (analog joystick to allow observers a gradual subjective report. We find that the "reflexes" reflect the percept rather than the physical stimulus. Both reflexes show a gradual dependence on the time relative to perceptual transitions. Similarly, observers' joystick deflections, which are highly correlated with the reflex measures, indicate gradual transitions. Physically simulating wave-like transitions between percepts suggest piece-meal rivalry (i.e., different regions of space belonging to distinct percepts as one possible explanation for the gradual transitions. Furthermore, the reflexes show that dominance durations depend on whether or not the percept is actively reported. In addition, reflexes respond to transitions with shorter latencies than the subjective report and show an abundance of short dominance durations. This failure to report fast changes in dominance may result from limited access of introspection to rivalry dynamics. In sum, reflexes reveal that rivalry is a gradual process, rivalry's dynamics is modulated by the required action (response mode, and that rapid transitions in perceptual dominance can slip away from awareness.

  11. Cortical microcircuit dynamics mediating Binocular Rivalry: The role of adaptation in inhibition

    Directory of Open Access Journals (Sweden)

    Panagiota eTheodoni

    2011-11-01

    Full Text Available Perceptual bistability arises when two conflicting interpretations of an ambiguous stimulus or images in binocular rivalry (BR compete for perceptual dominance. From a computational point of view competition models based on cross-inhibition and adaptation have shown that noise is a crucial force for rivalry and operates in balance with adaptation in order to explain the observed alternations in perception. In particular, noise-driven transitions and adaptation-driven oscillations define two dynamical regimes and the system operates near its boundary. In order to gain insights into the microcircuit dynamics mediating spontaneous perceptual alternations we used a reduced recurrent attractor-based biophysically realistic spiking network well known for working memory, attention and decision-making, where a spike-frequency adaptation mechanism is implemented to account for perceptual bistability. We, thus, derived a consistently reduced four-variable population rate model using mean-field techniques and tested it on BR data collected from human subjects. Our model accounts for experimental data parameters such as time dominance, coefficient of variation and gamma distribution. In addition, we show that our model also operates on the boundary between noise and adaptation and agrees with Levelt’s second revised and fourth propositions. These results show for the first time that a consistent reduction of a biophysically realistic spiking network of integrate and fire neurons with spike frequency adaptation could account for BR. Moreover, we demonstrate that BR can be explained only through the dynamics of the competing neuronal pools, without taking into account the adaptation of inhibitory interneurons..However, adaptation of interneurons affects the optimal parametric space of the system, by decreasing the overall adaptation necessary for the bifurcation to occur.

  12. Early visual responses predict conscious face perception within and between subjects during binocular rivalry.

    Science.gov (United States)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota; Barnes, Gareth Robert; Overgaard, Morten; Rees, Geraint

    2013-06-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170-800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using multivariate classification on MEG data recorded when participants reported changes in conscious perception evoked by binocular rivalry between a face and a grating, we showed that only MEG signals in the 120-320 msec time range, peaking at the M170 around 180 msec and the P2m at around 260 msec, reliably predicted conscious experience. Conscious perception could not only be decoded significantly better than chance from the sensors that showed the largest average difference, as previous studies suggest, but also from patterns of activity across groups of occipital sensors that individually were unable to predict perception better than chance. In addition, source space analyses showed that sources in the early and late visual system predicted conscious perception more accurately than frontal and parietal sites, although conscious perception could also be decoded there. Finally, the patterns of neural activity associated with conscious face perception generalized from one participant to another around the times of maximum prediction accuracy. Our work thus demonstrates that the neural correlates of particular conscious contents (here, faces) are highly consistent in time and space within individuals and that these correlates are shared to some extent between individuals.

  13. Naturalistic stimulus structure determines the integration of audiovisual looming signals in binocular rivalry.

    Directory of Open Access Journals (Sweden)

    Verena Conrad

    Full Text Available Rapid integration of biologically relevant information is crucial for the survival of an organism. Most prominently, humans should be biased to attend and respond to looming stimuli that signal approaching danger (e.g. predator and hence require rapid action. This psychophysics study used binocular rivalry to investigate the perceptual advantage of looming (relative to receding visual signals (i.e. looming bias and how this bias can be influenced by concurrent auditory looming/receding stimuli and the statistical structure of the auditory and visual signals. Subjects were dichoptically presented with looming/receding visual stimuli that were paired with looming or receding sounds. The visual signals conformed to two different statistical structures: (1 a 'simple' random-dot kinematogram showing a starfield and (2 a "naturalistic" visual Shepard stimulus. Likewise, the looming/receding sound was (1 a simple amplitude- and frequency-modulated (AM-FM tone or (2 a complex Shepard tone. Our results show that the perceptual looming bias (i.e. the increase in dominance times for looming versus receding percepts is amplified by looming sounds, yet reduced and even converted into a receding bias by receding sounds. Moreover, the influence of looming/receding sounds on the visual looming bias depends on the statistical structure of both the visual and auditory signals. It is enhanced when audiovisual signals are Shepard stimuli. In conclusion, visual perception prioritizes processing of biologically significant looming stimuli especially when paired with looming auditory signals. Critically, these audiovisual interactions are amplified for statistically complex signals that are more naturalistic and known to engage neural processing at multiple levels of the cortical hierarchy.

  14. Influence of Exclusive Binocular Rivalry on Perceived Depth in the `Sieve Effect'

    Science.gov (United States)

    Matsumiya, Kazumichi

    An impression of a surface seen through holes is created when one fuses dichoptic pairs of discs with one member of each pair black and the other white. This is referred to as the ‘sieve effect’. This stimulus contains no positional disparities. The impression of depth in the sieve effect is most evident when the size, contrast, and rim thickness of rivalrous patterns are such as to produce exclusive rivalry. I investigated how long it took for the sieve effect to recover from exclusive rivalry suppression. The magnitude of perceived depth in the effect was measured after exclusive rivalry suppression of one half-image of the sieve-effect stimulus. The results showed that the sieve effect takes approximately 630 ms to recover from exclusive rivalry suppression, compared with 200 ms for disparity-based stereopsis. Considered together with the previous report [Matsumiya and Howard: Invest. Ophthalmol. Visual Sci. 42 (2001) S403] that the sieve effect is positively correlated with the rate of exclusive rivalry, these findings suggest that the effect and exclusive rivalry are processed in the identical channel.

  15. Duality in binocular rivalry: distinct sensitivity of percept sequence and percept duration to imbalance between monocular stimuli.

    Directory of Open Access Journals (Sweden)

    Chen Song

    Full Text Available BACKGROUND: Visual perception is usually stable and accurate. However, when the two eyes are simultaneously presented with conflicting stimuli, perception falls into a sequence of spontaneous alternations, switching between one stimulus and the other every few seconds. Known as binocular rivalry, this visual illusion decouples subjective experience from physical stimulation and provides a unique opportunity to study the neural correlates of consciousness. The temporal properties of this alternating perception have been intensively investigated for decades, yet the relationship between two fundamental properties - the sequence of percepts and the duration of each percept - remains largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Here we examine the relationship between the percept sequence and the percept duration by quantifying their sensitivity to the strength imbalance between two monocular stimuli. We found that the percept sequence is far more susceptible to the stimulus imbalance than does the percept duration. The percept sequence always begins with the stronger stimulus, even when the stimulus imbalance is too weak to cause a significant bias in the percept duration. Therefore, introducing a small stimulus imbalance affects the percept sequence, whereas increasing the imbalance affects the percept duration, but not vice versa. To investigate why the percept sequence is so vulnerable to the stimulus imbalance, we further measured the interval between the stimulus onset and the first percept, during which subjects experienced the fusion of two monocular stimuli. We found that this interval is dramatically shortened with increased stimulus imbalance. CONCLUSIONS/SIGNIFICANCE: Our study shows that in binocular rivalry, the strength imblanace between monocular stimuli has a much greater impact on the percept sequence than on the percept duration, and increasing this imbalance can accelerate the process responsible for the percept sequence.

  16. How Auditory Information Influences Volitional Control in Binocular Rivalry: Modulation of a Top-Down Attentional Effect

    Directory of Open Access Journals (Sweden)

    Manuel Vidal

    2011-10-01

    / although it could be equivalent to promoting lips uttering /ada/. Our findings suggest that at higher-level processing stages, auditory cues do interact with the perceptual decision and with the dominance mechanism involved during visual rivalry. These results are discussed according to the individual differences in the audio-visual integration for speech perception. We propose a descriptive model based on known characteristics of binocular rivalry, which accounts for most of these findings. In this model, the top-down attentional control (volition is modulated by lower-level audio-visual matching.

  17. Percept-switch nucleation in binocular rivalry reveals local adaptation characteristics of early visual processing

    NARCIS (Netherlands)

    van Ee, R.

    2011-01-01

    When the two eyes view incompatible images that subtend the entire visual field, perception alternates between the two images unpredictably: at seemingly random times and locations, observers experience sudden changes in the awareness of the unchanging visual stimulation. Here we focus on the very f

  18. Colour-grapheme synesthesia affects binocular vision.

    Science.gov (United States)

    Paffen, Chris L E; van der Smagt, Maarten J; Nijboer, Tanja C W

    2011-01-01

    In colour-grapheme synesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it is debated whether visual processing of synesthesia-inducing achromatic graphemes is similar to that of chromatic graphemes. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic digits that induce synesthetic colour percepts increase the incidence of binocular rivalry compared to achromatic non-digits that do not evoke such percepts. That is, compared to achromatically perceived non-digits, synesthesia-inducing digits increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synesthetic colour experience can provide the conditions for promoting binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  19. Colour-grapheme synaesthesia affects binocular vision

    Directory of Open Access Journals (Sweden)

    Chris L.E. Paffen

    2011-11-01

    Full Text Available In colour-grapheme synaesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it has become evident that synaesthesia-inducing graphemes can affect visual processing in a manner comparable to real, physical colours. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic graphemes that induce synaesthetic colour percepts evoke binocular rivalry, while without the synaesthetic percept, they do not. That is, compared to achromatically perceived graphemes, synaesthesia-inducing graphemes increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synaesthetic colour experience can provide the conditions for evoking binocular rivalry, much like stimulus features that induce rivalry in normal vision.

  20. Attention modulation of stimulus rivalry under swapping paradigm

    Science.gov (United States)

    Doualot, Audrey; Simard, Mathieu; Saint-Amour, Dave

    2014-01-01

    Stimulus rivalry refers to the sustained periods of perceptual dominance that occur when different visual stimuli are swapped at a regular rate between eyes. This phenomenon is thought to involve mainly eye-independent mechanisms. Although several studies have reported that attention can increase image predominance in conventional binocular rivalry, it is unknown whether attention can specifically modulate stimulus rivalry. We addressed this question and manipulated the spatial characteristic of the stimuli to assess whether such an attention modulation could depend on visual processing hierarchy. The results showed that selective attention of stimulus rivalry significantly increased the predominance of the attended stimulus, regardless of the stimulus' spatial characteristics. No effect was observed on the swapping percept. The findings are discussed in the context of recent models attempting to characterize stimulus rivalry between eye-dependent and eye-independent levels. PMID:25469220

  1. fMRI investigation of monocular pattern rivalry.

    Science.gov (United States)

    Mendola, Janine D; Buckthought, Athena

    2013-01-01

    In monocular pattern rivalry, a composite image is shown to both eyes. The patient experiences perceptual alternations in which the two stimulus components alternate in clarity or salience. We used fMRI at 3T to image brain activity while participants perceived monocular rivalry passively or indicated their percepts with a task. The stimulus patterns were left/right oblique gratings, face/house composites, or a nonrivalrous control stimulus that did not support the perception of transparency or image segmentation. All stimuli were matched for luminance, contrast, and color. Compared with the control stimulus, the cortical activation for passive viewing of grating rivalry included dorsal and ventral extrastriate cortex, superior and inferior parietal regions, and multiple sites in frontal cortex. When the BOLD signal for the object rivalry task was compared with the grating rivalry task, a similar whole-brain network was engaged, but with significantly greater activity in extrastriate regions, including V3, V3A, fusiform face area (FFA), and parahippocampal place area (PPA). In addition, for the object rivalry task, FFA activity was significantly greater during face-dominant periods whereas parahippocampal place area activity was greater during house-dominant periods. Our results demonstrate that slight stimulus changes that trigger monocular rivalry recruit a large whole-brain network, as previously identified for other forms of bistability. Moreover, the results indicate that rivalry for complex object stimuli preferentially engages extrastriate cortex. We also establish that even with natural viewing conditions, endogenous attentional fluctuations in monocular pattern rivalry will differentially drive object-category-specific cortex, similar to binocular rivalry, but without complete suppression of the nondominant image.

  2. Parabolic flight reveals independent binocular control of otolith-induced eye torsion

    Science.gov (United States)

    Markham, C. H.; Diamond, S. G.; Stoller, D. F.

    2000-01-01

    To examine otolith-governed ocular torsion in hyper- and hypogravity, eight subjects, including two astronauts, underwent parabolic flight while seated upright with head fixed. A mask fitted with two video cameras provided synchronized images of both eyes at a rate of 25/sec during 15 parabolas, the individual parabolas separated by a few minutes of level 1 G flight. Three main findings emerged: 1) After the first parabola, most subjects showed differential torsional offset of the two eyes in the 1 G portions between parabolas, compared to the conjugate baseline position of the eyes prior to the first parabola. 2) Changes in binocular torsion in the 0 G and 1.8 G portions of parabolic flight revealed in most subjects systematic reversal of direction. The reversal was consistent within, but not across subjects. 3) Disconjugacy defined as the moment-to-moment difference in the movements of the two eyes, and evaluated without the contribution of the differential offset, found two subjects with relatively high disconjugacy scores, and the remaining six with low scores. On the basis of prior studies (9, 20), we would predict the first two would be subject to SMS, the remainder not. The two astronauts, who did not have SMS on their space missions, fell into the low scoring group. We propose that the disconjugacies may be due to intrinsic asymmetries in the otolith receptors on the two sides of the head, which appear to be independently linked to the extraocular muscles of the two eyes, a phenomenon masked in normal 1 G states by adaptation. The apparently independent control of the two sides cannot be detected by the simpler and more common monocular studies.

  3. Binocular combination in abnormal binocular vision.

    Science.gov (United States)

    Ding, Jian; Klein, Stanley A; Levi, Dennis M

    2013-02-08

    We investigated suprathreshold binocular combination in humans with abnormal binocular visual experience early in life. In the first experiment we presented the two eyes with equal but opposite phase shifted sine waves and measured the perceived phase of the cyclopean sine wave. Normal observers have balanced vision between the two eyes when the two eyes' images have equal contrast (i.e., both eyes contribute equally to the perceived image and perceived phase = 0°). However, in observers with strabismus and/or amblyopia, balanced vision requires a higher contrast image in the nondominant eye (NDE) than the dominant eye (DE). This asymmetry between the two eyes is larger than predicted from the contrast sensitivities or monocular perceived contrast of the two eyes and is dependent on contrast and spatial frequency: more asymmetric with higher contrast and/or spatial frequency. Our results also revealed a surprising NDE-to-DE enhancement in some of our abnormal observers. This enhancement is not evident in normal vision because it is normally masked by interocular suppression. However, in these abnormal observers the NDE-to-DE suppression was weak or absent. In the second experiment, we used the identical stimuli to measure the perceived contrast of a cyclopean grating by matching the binocular combined contrast to a standard contrast presented to the DE. These measures provide strong constraints for model fitting. We found asymmetric interocular interactions in binocular contrast perception, which was dependent on both contrast and spatial frequency in the same way as in phase perception. By introducing asymmetric parameters to the modified Ding-Sperling model including interocular contrast gain enhancement, we succeeded in accounting for both binocular combined phase and contrast simultaneously. Adding binocular contrast gain control to the modified Ding-Sperling model enabled us to predict the results of dichoptic and binocular contrast discrimination experiments

  4. Binocular astronomy

    CERN Document Server

    Tonkin, Stephen

    2014-01-01

    Binoculars have, for many, long been regarded as an “entry level” observational tool, and relatively few have used them as a serious observing instrument. This is changing! Many people appreciate the relative comfort of two-eyed observing, but those who use binoculars come to realize that they offer more than comfort. The view of the stars is more aesthetically pleasing and therefore binocular observers tend to observe more frequently and for longer periods. Binocular Astronomy, 2nd Edition, extends its coverage of small and medium binoculars to large and giant (i.e., up to 300mm aperture) binoculars and also binoviewers, which brings the work into the realm of serious observing instruments. Additionally, it goes far deeper into the varying optical characteristics of binoculars, giving newcomers and advanced astronomers the information needed to make informed choices on purchasing a pair. It also covers relevant aspects of the physiology of binocular (as in “both eyes”) observation. The first edition ...

  5. A Sour Milk Rivalry

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A libel scandal involving Mengniu taints its image and deals a blow to China’s dairy industry Mengniu,with the 2008 milk contamination incident still fresh in people’s memories,has brought China’s dairy industry into the spotlight again-this time the attention focused on a bitter rivalry.

  6. A Sour Milk Rivalry

    Institute of Scientific and Technical Information of China (English)

    LAN XINZHEN

    2010-01-01

    @@ Mengniu,with the 2008 milk con tamination incident still fresh in people's memories,has brought China's dairy industry into the spotlight again-this time the attention focused on a bitter rivalry. Police in Hohhot,capital of the Inner Mongolian Autonomous Region,held a press briefing on October 22 over a Mengniu-initiated smear campaign against its rival,Yili.

  7. Canonical Cortical Circuit Model Explains Rivalry, Intermittent Rivalry, and Rivalry Memory.

    Directory of Open Access Journals (Sweden)

    Shashaank Vattikuti

    2016-05-01

    Full Text Available It has been shown that the same canonical cortical circuit model with mutual inhibition and a fatigue process can explain perceptual rivalry and other neurophysiological responses to a range of static stimuli. However, it has been proposed that this model cannot explain responses to dynamic inputs such as found in intermittent rivalry and rivalry memory, where maintenance of a percept when the stimulus is absent is required. This challenges the universality of the basic canonical cortical circuit. Here, we show that by including an overlooked realistic small nonspecific background neural activity, the same basic model can reproduce intermittent rivalry and rivalry memory without compromising static rivalry and other cortical phenomena. The background activity induces a mutual-inhibition mechanism for short-term memory, which is robust to noise and where fine-tuning of recurrent excitation or inclusion of sub-threshold currents or synaptic facilitation is unnecessary. We prove existence conditions for the mechanism and show that it can explain experimental results from the quartet apparent motion illusion, which is a prototypical intermittent rivalry stimulus.

  8. Modulating the rate and rhythmicity of perceptual rivalry alternations with the mixed 5-HT2A and 5-HT1A agonist psilocybin.

    Science.gov (United States)

    Carter, Olivia L; Pettigrew, John D; Hasler, Felix; Wallis, Guy M; Liu, Guang B; Hell, Daniel; Vollenweider, Franz X

    2005-06-01

    Binocular rivalry occurs when different images are presented simultaneously to corresponding points within the left and right eyes. Under these conditions, the observer's perception will alternate between the two perceptual alternatives. Motivated by the reported link between the rate of perceptual alternations, symptoms of psychosis and an incidental observation that the rhythmicity of perceptual alternations during binocular rivalry was greatly increased 10 h after the consumption of LSD, this study aimed to investigate the pharmacology underlying binocular rivalry and to explore the connection between the timing of perceptual switching and psychosis. Psilocybin (4-phosphoryloxy-N,N-dimethyltryptamine, PY) was chosen for the study because, like LSD, it is known to act as an agonist at serotonin (5-HT)1A and 5-HT2A receptors and to produce an altered state sometimes marked by psychosis-like symptoms. A total of 12 healthy human volunteers were tested under placebo, low-dose (115 microg/kg) and high-dose (250 microg/kg) PY conditions. In line with predictions, under both low- and high-dose conditions, the results show that at 90 min postadministration (the peak of drug action), rate and rhythmicity of perceptual alternations were significantly reduced from placebo levels. Following the 90 min testing period, the perceptual switch rate successively increased, with some individuals showing increases well beyond pretest levels at the final testing, 360 min postadministration. However, as some subjects had still not returned to pretest levels by this time, the mean phase duration at 360 min was not found to differ significantly from placebo. Reflecting the drug-induced changes in rivalry phase durations, subjects showed clear changes in psychological state as indexed by the 5D-ASC (altered states of consciousness) rating scales. This study suggests the involvement of serotonergic pathways in binocular rivalry and supports the previously proposed role of a brainstem

  9. Effects of time-dependent stimuli in a competitive neural network model of perceptual rivalry.

    Science.gov (United States)

    Jayasuriya, Suren; Kilpatrick, Zachary P

    2012-06-01

    We analyze a competitive neural network model of perceptual rivalry that receives time-varying inputs. Time-dependence of inputs can be discrete or smooth. Spike frequency adaptation provides negative feedback that generates network oscillations when inputs are constant in time. Oscillations that resemble perceptual rivalry involve only one population being “ON” at a time, which represents the dominance of a single percept at a time. As shown in Laing and Chow (J. Comput. Neurosci. 12(1):39–53, 2002), for sufficiently high contrast, one can derive relationships between dominance times and contrast that agree with Levelt’s propositions (Levelt in On binocular rivalry, 1965). Time-dependent stimuli give rise to novel network oscillations where both, one, or neither populations are “ON” at any given time. When a single population receives an interrupted stimulus, the fundamental mode of behavior we find is phase-locking, where the temporally driven population locks its state to the stimulus. Other behaviors are analyzed as bifurcations from this forced oscillation, using fast/slow analysis that exploits the slow timescale of adaptation. When both populations receive time-varying input, we find mixtures of fusion and sole population dominance, and we partition parameter space into particular oscillation types. Finally, when a single population’s input contrast is smoothly varied in time, 1:n mode-locked states arise through period-adding bifurcations beyond phase-locking. Our results provide several testable predictions for future psychophysical experiments on perceptual rivalry.

  10. Generic Rivalry Strategies in Business Networks: Towards a Conceptualization

    DEFF Research Database (Denmark)

    Andersen, Poul Houman

    2008-01-01

    This paper discusses rivalry as a process of occupying incompatible positions within business networks. Rivalry is linked to different forms of strategizing as they unfold in stable and dynamic business contexts and a framework of four different types of rivalry is suggested. Furthermore, proposi...

  11. Augmented Reality Binoculars.

    Science.gov (United States)

    Oskiper, Taragay; Sizintsev, Mikhail; Branzoi, Vlad; Samarasekera, Supun; Kumar, Rakesh

    2015-05-01

    In this paper we present an augmented reality binocular system to allow long range high precision augmentation of live telescopic imagery with aerial and terrain based synthetic objects, vehicles, people and effects. The inserted objects must appear stable in the display and must not jitter and drift as the user pans around and examines the scene with the binoculars. The design of the system is based on using two different cameras with wide field of view and narrow field of view lenses enclosed in a binocular shaped shell. Using the wide field of view gives us context and enables us to recover the 3D location and orientation of the binoculars much more robustly, whereas the narrow field of view is used for the actual augmentation as well as to increase precision in tracking. We present our navigation algorithm that uses the two cameras in combination with an inertial measurement unit and global positioning system in an extended Kalman filter and provides jitter free, robust and real-time pose estimation for precise augmentation. We have demonstrated successful use of our system as part of information sharing example as well as a live simulated training system for observer training, in which fixed and rotary wing aircrafts, ground vehicles, and weapon effects are combined with real world scenes.

  12. Interdependence and the social structure of rivalry

    NARCIS (Netherlands)

    Carroll, Charles

    1998-01-01

    Outcome interdependence predisposes firms to simultaneously cooperate and compete. Hence, it may shape the social structure of rivalry. Outcome interdependence may stem from similarities in (a) types of suppliers/buyers, (b) resources, (c) geographic catchment areas, and (d) strategic beliefs of man

  13. Amblyopia and binocular vision.

    Science.gov (United States)

    Birch, Eileen E

    2013-03-01

    Amblyopia is the most common cause of monocular visual loss in children, affecting 1.3%-3.6% of children. Current treatments are effective in reducing the visual acuity deficit but many amblyopic individuals are left with residual visual acuity deficits, ocular motor abnormalities, deficient fine motor skills, and risk for recurrent amblyopia. Using a combination of psychophysical, electrophysiological, imaging, risk factor analysis, and fine motor skill assessment, the primary role of binocular dysfunction in the genesis of amblyopia and the constellation of visual and motor deficits that accompany the visual acuity deficit has been identified. These findings motivated us to evaluate a new, binocular approach to amblyopia treatment with the goals of reducing or eliminating residual and recurrent amblyopia and of improving the deficient ocular motor function and fine motor skills that accompany amblyopia.

  14. A gain-control theory of binocular combination.

    Science.gov (United States)

    Ding, Jian; Sperling, George

    2006-01-24

    In binocular combination, light images on the two retinas are combined to form a single "cyclopean" perceptual image, in contrast to binocular rivalry which occurs when the two eyes have incompatible ("rivalrous") inputs and only one eye;s stimulus is perceived. We propose a computational theory for binocular combination with two basic principles of interaction: in every spatial neighborhood, each eye (i) exerts gain control on the other eye's signal in proportion to the contrast energy of its own input and (ii) additionally exerts gain control on the other eye's gain control. For stimuli of ordinary contrast, when either eye is stimulated alone, the predicted cyclopean image is the same as when both eyes are stimulated equally, coinciding with an easily observed property of natural vision. The gain-control theory is contrast dependent: Very low-contrast stimuli to the left- and right-eye add linearly to form the predicted cyclopean image. The intrinsic nonlinearity manifests itself only as contrast increases. To test the theory more precisely, a horizontal sine wave grating of 0.68 cycles per degree is presented to each eye. The gratings differ in contrast and phase. The predicted (and perceived) cyclopean grating also is a sine wave; its apparent phase indicates the relative contribution of the two eyes to the cyclopean image. For 48 measured combinations of phase and contrast, the theory with only one estimated parameter accounts for 95% of the variance of the data. Therefore, a simple, robust, physiologically plausible gain-control theory accurately describes an early stage of binocular combination.

  15. Binocular responses and vertical strabismus

    Directory of Open Access Journals (Sweden)

    Risović Dušica

    2007-01-01

    Full Text Available Background/Aim. Elevation in adduction is the most common pattern of vertical strabismus, and it is mostly treated with surgery. The results of weaking of inferior oblique muscle are very changeable. The aim of this study was to evaluate binocular vision using sensory tests before and one and six months after the surgery. Methods. A total of 79 children were divided in two groups: the first, with inferior oblique muscle of overaction (n = 52, and the second with dissociated vertical deviation (DVD, and primary inferior oblique muscle overaction (n = 27. We tested them by polaroid mirror test (PMT, Worth test at distance and near, fusion amplitudes on sinoptofore, Lang I stereo test and Wirt-Titmus stereo test. We examined our patients before and two times after the surgery for vertical strabismus. Results. Foveal suppression in the group I was found in 60.5% of the patients before, and in 56.4% after the surgery. In group II Foveal suppression was detected in 64.7% of the patients before, but in 55.6% 6 months after the surgery with PMT. Worth test revealed suppression in 23.5% of the patients before, and in 40.7% after the vertical muscle surgery. Parafoveal fussion persisted in about 1/3 of the patients before the surgery, and their amplitudes were a little larger after the surgery in the group I patients. Lang I stereo test was negative in 53.9% before and 51.9% after the surgery in the group I, and in 48.2% of the patients before and after the surgery in the group II patients. Wirt-Titmus stereo test was negative in 74.5% of the patients before and in 72.9% after the surgery in the group I, but in the group II it was negative in 70.8% before and in 68.0% of the patients 6 months after the surgery. Conclusion. Binocular responses were found after surgery in 65.7% of the patients the group I and in 55.6% patients the group II. There was no significant difference between these two groups, but binocular responses were more often in the patients

  16. Aerial Reconnaissance Binoculars

    Science.gov (United States)

    1974-06-01

    199212 Z= 8,51005 L= 0 M= 204139-4 N= . Table 1.2 Marginal ray height for zero degroos Ineldont rayo YO= .6 X ) Y= .60795 Z= 3-96631E-p X 0 Y= .6143...in high vibration environments where standard military binoculars (7 x 50) are only marginally helpful to the naked eye in the detection of targets...of-view 17.8 degrees Exit Pupil 9.65 mm Eye Relief 274 mm Size 4.5 x 8.75 x 3.5 inches Weight 4.3 lbs 3 2. Computer Design - Ray Tracing of Original

  17. MONOCULAR AND BINOCULAR VISION IN THE PERFORMANCE OF A COMPLEX SKILL

    Directory of Open Access Journals (Sweden)

    Thomas Heinen

    2011-09-01

    Full Text Available The goal of this study was to investigate the role of binocular and monocular vision in 16 gymnasts as they perform a handspring on vault. In particular we reasoned, if binocular visual information is eliminated while experts and apprentices perform a handspring on vault, and their performance level changes or is maintained, then such information must or must not be necessary for their best performance. If the elimination of binocular vision leads to differences in gaze behavior in either experts or apprentices, this would answer the question of an adaptive gaze behavior, and thus if this is a function of expertise level or not. Gaze behavior was measured using a portable and wireless eye-tracking system in combination with a movement-analysis system. Results revealed that gaze behavior differed between experts and apprentices in the binocular and monocular conditions. In particular, apprentices showed less fixations of longer duration in the monocular condition as compared to experts and the binocular condition. Apprentices showed longer blink duration than experts in both, the monocular and binocular conditions. Eliminating binocular vision led to a shorter repulsion phase and a longer second flight phase in apprentices. Experts exhibited no differences in phase durations between binocular and monocular conditions. Findings suggest, that experts may not rely on binocular vision when performing handsprings, and movement performance maybe influenced in apprentices when eliminating binocular vision. We conclude that knowledge about gaze-movement relationships may be beneficial for coaches when teaching the handspring on vault in gymnastics

  18. On rivalry and goal pursuit: Shared competitive history, legacy concerns, and strategy selection.

    Science.gov (United States)

    Converse, Benjamin A; Reinhard, David A

    2016-02-01

    Seven studies converge to show that prompting people to think about a rival versus a nonrival competitor causes them to view current competitions as more connected to past ones, to be more concerned with long-term legacy, and to pursue personal goals in a more eager, less cautious manner. These results are consistent with a social-cognitive view of rivalry that defines it as a competitive relational schema. A preliminary analysis revealed that people were more likely to appeal to past competitions to explain the importance of current rivalry than nonrivalry contests. Experiment 1 showed that people view rivalry versus nonrivalry competitions as more embedded in an ongoing competitive narrative and that this perception increases legacy concerns. The next 2 experiments used a causal chain approach to examine the possibility of legacy concerns acting as a mediator between rivalry and eagerness. Experiment 2a demonstrated that longer (vs. shorter) competitive histories are associated with increased legacy concerns. Experiment 2b manipulated legacy concerns and found that this shifted regulatory focus toward eagerness. Finally, 3 experiments tested the direct effect of thinking about a rival on eager strategy selection: Thinking about rivals (vs. nonrivals) led people to be more interested in offensive than defensive strategies (Experiment 3), to initiate rather than delay their goal pursuit (Experiment 4), and to rely on spontaneous rather than deliberative reasoning (Experiment 5). We suggest that rivalries affect how people view their goals and the strategies they use for pursuing them, and that these effects are at least partially attributable to the shared history between individuals and their rivals.

  19. Early visual responses predict conscious face perception within and between subjects during binocular rivalry

    DEFF Research Database (Denmark)

    Sandberg, Kristian; Bahrami, Bahador; Kanai, Ryota

    2013-01-01

    Previous studies indicate that conscious face perception may be related to neural activity in a large time window around 170–800 msec after stimulus presentation, yet in the majority of these studies changes in conscious experience are confounded with changes in physical stimulation. Using...

  20. Large Binocular Telescope Project

    Science.gov (United States)

    Hill, John M.

    1997-03-01

    The large binocular telescope (LBT) project have evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 by 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson, Arizona. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train -- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in the fall of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1996 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson), EIE and ADS Italia

  1. A Model for Rivalry between Cognitive Contours

    Science.gov (United States)

    1990-04-01

    of the illusory 9 lines. These, however, were not so crucial for the shape or the ’ Gestalt ’ of the target in the case of the ’star’ and ’cross’ is...phenomenon as ’high-level’, namely as the appearance of another ’ Gestalt ’, the ’star’ that prevents rivalry. But there is also a structural explanation...1955) Margini quasi-percettivi in campi con stimolazione omogenea. Rivista di Psicologia 49, 17-30. Lawson, R.B., Cowan, E., Gibbs, T.D. & Whitmore

  2. Binocular adaptive optics visual simulator.

    Science.gov (United States)

    Fernández, Enrique J; Prieto, Pedro M; Artal, Pablo

    2009-09-01

    A binocular adaptive optics visual simulator is presented. The instrument allows for measuring and manipulating ocular aberrations of the two eyes simultaneously, while the subject performs visual testing under binocular vision. An important feature of the apparatus consists on the use of a single correcting device and wavefront sensor. Aberrations are controlled by means of a liquid-crystal-on-silicon spatial light modulator, where the two pupils of the subject are projected. Aberrations from the two eyes are measured with a single Hartmann-Shack sensor. As an example of the potential of the apparatus for the study of the impact of the eye's aberrations on binocular vision, results of contrast sensitivity after addition of spherical aberration are presented for one subject. Different binocular combinations of spherical aberration were explored. Results suggest complex binocular interactions in the presence of monochromatic aberrations. The technique and the instrument might contribute to the better understanding of binocular vision and to the search for optimized ophthalmic corrections.

  3. Bion and binocular vision.

    Science.gov (United States)

    Mason, A

    2000-10-01

    The author describes his contact with Bion over a twenty-year period, from Bion's supervision of his control case in London in 1960 to the period from 1968 to 1978 when they were both working in Los Angeles. He outlines Bion's views on the use of 'instinct' and intuition in patient observation, the depressive position in patient and analyst, and memory and desire as impediments to knowledge of 'ultimate reality'. Some case material is presented, illustrating how Bion's ideas, particularly concerning attacks on linking, informed the course of the treatment. The author then discusses Freud's, Klein's and Bion's approaches to the problem of resistance, Bion's expansion of some of Klein's ideas, his definitions of psychosis and his formulation concerning thoughts that develop before thinking. The author then argues how essential it is for the analyst to differentiate between primitive projections from the patient that are pre-verbal attempts to communicate a state of mind and those that are an expression of hostility or control. He then discusses the importance of understanding idealizing projections and differentiating these from a healthy positive transference. He concludes by characterising Bion's way of working in terms of his humility, his courage and, fundamentally, his use of his intuitive binocular mind.

  4. Optimization Design for Digital Binoculars

    Institute of Scientific and Technical Information of China (English)

    CEN Jun-bo; CHEN Wei-min; LI Hui; HUANG Shang-lian

    2005-01-01

    In order to develop competitive and high performance/cost ratio of digital binoculars, design scheme should be optimized in term of technical capacity, economic benefit, product performance, risk management, etc. The common optimization method is limited in qualitative analysis, and the parameter optimization method is limited in obtaining optimal parameter only from technical side. Each method has its limitation. Based on the analysis of digital binoculars parameters, optional design schemes are laid down.Analytic hierarchy process combined the qualitative analysis with the quantitative analysis together. The design schemes are optimized, and result is worked out.

  5. Assessing the binocular advantage in aided vision.

    Science.gov (United States)

    Harrington, Lawrence K; McIntire, John P; Hopper, Darrel G

    2014-09-01

    Advances in microsensors, microprocessors, and microdisplays are creating new opportunities for improving vision in degraded environments through the use of head-mounted displays. Initially, the cutting-edge technology used in these new displays will be expensive. Inevitably, the cost of providing the additional sensor and processing required to support binocularity brings the value of binocularity into question. Several assessments comparing binocular, binocular, and monocular head-mounted displays for aided vision have concluded that the additional performance, if any, provided by binocular head-mounted displays does not justify the cost. The selection of a biocular [corrected] display for use in the F-35 is a current example of this recurring decision process. It is possible that the human binocularity advantage does not carry over to the aided vision application, but more likely the experimental approaches used in the past have been too coarse to measure its subtle but important benefits. Evaluating the value of binocularity in aided vision applications requires an understanding of the characteristics of both human vision and head-mounted displays. With this understanding, the value of binocularity in aided vision can be estimated and experimental evidence can be collected to confirm or reject the presumed binocular advantage, enabling improved decisions in aided vision system design. This paper describes four computational approaches-geometry of stereopsis, modulation transfer function area for stereopsis, probability summation, and binocular summation-that may be useful in quantifying the advantage of binocularity in aided vision.

  6. Competitive and rivalry behaviors in international business exchanges

    DEFF Research Database (Denmark)

    Medlin, C. J.; Ellegaard, Chris

    In this paper we explore competition as a process between firms; rather than as a background economic variable. We consider past competitor research on structured contexts and socially constructed competition, and develop a research model based on the priority of firm’s line of action: whether pr...... activity. We complete the paper with the opportunities for future research and also managerial thinking about competition in business markets....... primarily towards the customers or towards other firms. We explore the theoretical distinctions between non-competitive, competitive, and rivalry firm behavior through an analysis of wine exporters and importers of fine wine to Denmark from Southern Australia. We find examples of competitive and rivalry...

  7. Academic Entrepreneurship and Traditional Academic Duties: Synergy or Rivalry?

    Science.gov (United States)

    De Silva, Muthu

    2016-01-01

    This study investigates the influence of academic entrepreneurship on traditional academic duties carried out in a resource-constrained environment, particularly focusing on whether there is synergy or rivalry between these two activities. Using qualitative evidence, we discover that there are funding, resource, knowledge and skill and networking…

  8. Assessing Binocular Advantage in Aided Vision

    Science.gov (United States)

    2014-06-01

    Night /day Imaging Technologies, ANIT, Head Mounted Display, Night Vision Goggle , Aided Vision , Binocular...advantage of binocularity in aided vision . Key Words: Head Mounted Display, Night Vision Goggle , Stereopsis, Modulation Transfer Function...veridical perception allows the operator to navigate and manipulate the environment in a natural and efficient manner. Night vision goggles (NVGs),

  9. Effect of aniseikonia on binocular function.

    Science.gov (United States)

    Katsumi, O; Tanino, T; Hirose, T

    1986-04-01

    The pattern reversal visual evoked response (VER) was recorded under conditions of artificially unbalanced visual input between two eyes, an aniseikonia induced by size lenses that alter the perceived retinal image size without changing refraction. At 3.0% aniseikonia binocular summation started to decrease, and at 5.0% aniseikonia there was no significant binocular summation. In higher aniseikonia (8.0-10.0%), binocular inhibition replaced binocular summation. The phase difference between binocular and monocular VER was largest at zero aniseikonia. When aniseikonia exceeded 5.0%, there was no significant phase difference between the two recording conditions. These results suggested that the binocular system can compensate for up to a 3.0% difference in perceived retinal image size (aniseikonia), but in higher aniseikonia the binocular system can no longer compensate for the difference and binocular inhibition takes place. These findings agree with previously reported subjective and psychophysical results. The authors suggest that this objective method of evaluation using the pattern reversal VER may be helpful in pediatric ophthalmology when subjective methods are of limited use.

  10. The Large Binocular Telescope Project

    Science.gov (United States)

    Hill, J. M.

    1995-05-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astrofisico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in spring of 1996 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximicrons flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximicrons stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia

  11. Binocular depth acuity research to support the modular multi-spectral stereoscopic night vision goggle

    Science.gov (United States)

    Merritt, John O.; CuQlock-Knopp, V. Grayson; Paicopolis, Peter; Smoot, Jennifer; Kregel, Mark; Corona, Bernard

    2006-05-01

    This paper discusses the depth acuity research conducted in support of the development of a Modular Multi-Spectral Stereoscopic (M2S2) night vision goggle (NVG), a customizable goggle that lets the user select one of five goggle configurations: monocular thermal, monocular image intensifier (I2), binocular I2, binocular thermal, and binocular dual-waveband (thermal imagery to one eye and I2 imagery to the other eye). The motives for the development of this type of customizable goggle were (1) the need for an NVG that allows the simultaneous use of two wavebands, (2) the need for an alternative sensor fusion method to avoid the potential image degradation that may accompany digitally fused images, (3) a requirement to provide the observer with stereoscopic, dual spectrum views of a scene, and (4) the need to handle individual user preferences for sensor types and ocular configurations employed in various military operations. Among the increases in functionality that the user will have with this system is the ability to convert from a binocular I2 device (needed for detailed terrain analysis during off-road mobility) to a monocular thermal device (for increased situational awareness in the unaided eye during nights with full moon illumination). Results of the present research revealed potential depth acuity advantages that may apply to off-road terrain hazard detection for the binocular thermal configuration. The results also indicated that additional studies are needed to address ways to minimize binocular incompatibility for the dual waveband configuration.

  12. The Effect of Competitive Rivalry on Internal Communication in Private Healthcare Organizations: Evidence from Istanbul, Turkey

    Directory of Open Access Journals (Sweden)

    Gültekin Altuntas

    2014-02-01

    Full Text Available Both competitive rivalry and internal communication play a crucial role for a business to position itself in a favourable manner in order to succeed particularly in a hostile environment. While numerous studies present the importance of competitive rivalry and of communication, even internal communication separately, little is known about the specific linkage of how competitive rivalry affects communication in the literature. Within the framework of internal communication, this study focuses on the notion that competitive rivalry is related to the path and style of communication as well as to the usage of internal communication tools but not to quality of communication. Thus, our research presents the linkage and the interaction between competitive rivalry and internal communication, of which the results indicate that, overall, competitive rivalry has a significant direct positive influence on internal communication dimensions in terms of path, style and quality of communication, as well as usage of communication tools in healthcare organizations.

  13. Attentional switching in humans and flies: rivalry in large and miniature brains

    Directory of Open Access Journals (Sweden)

    Steven Mark Miller

    2012-01-01

    Full Text Available Human perception, and consequently behaviour, is driven by attention dynamics. In the special case of rivalry, where attention alternates between competing percepts, such dynamics can be measured and their determinants investigated. A recent study in the fruit fly, Drosophila melanogaster, now shows that the origins of attentional rivalry may be quite ancient. Furthermore, individual variation exists in the rate of attentional rivalry in both humans and flies, and in humans this is under substantial genetic influence. In the pathophysiological realm, slowing of rivalry rate is associated with the heritable psychiatric condition, bipolar disorder. Fly rivalry may therefore prove a powerful model to examine genetic and molecular influences on rivalry rate, and may even shed light on human cognitive and behavioural dysfunction.

  14. Geographical influences of an emerging network of gang rivalries

    Science.gov (United States)

    Hegemann, Rachel A.; Smith, Laura M.; Barbaro, Alethea B. T.; Bertozzi, Andrea L.; Reid, Shannon E.; Tita, George E.

    2011-10-01

    We propose an agent-based model to simulate the creation of street gang rivalries. The movement dynamics of agents are coupled to an evolving network of gang rivalries, which is determined by previous interactions among agents in the system. Basic gang data, geographic information, and behavioral dynamics suggested by the criminology literature are integrated into the model. The major highways, rivers, and the locations of gangs’ centers of activity influence the agents’ motion. We use a policing division of the Los Angeles Police Department as a case study to test our model. We apply common metrics from graph theory to analyze our model, comparing networks produced by our simulations and an instance of a Geographical Threshold Graph to the existing network from the criminology literature.

  15. The Effect of Competitive Rivalry on Internal Communication in Private Healthcare Organizations: Evidence from Istanbul, Turkey

    OpenAIRE

    Gültekin Altuntas; Fatih Semerciöz; Aral Noyan

    2014-01-01

    Both competitive rivalry and internal communication play a crucial role for a business to position itself in a favourable manner in order to succeed particularly in a hostile environment. While numerous studies present the importance of competitive rivalry and of communication, even internal communication separately, little is known about the specific linkage of how competitive rivalry affects communication in the literature. Within the framework of internal communication, this st...

  16. India-China Rivalry and Strategic Options for Bangladesh

    Science.gov (United States)

    2013-06-14

    Indian Ocean surfaced as a new form of dispute between these two countries. The spillover effect of this rivalry impacts the regional small states...growth of both India and China, the strategic context of South Asia is likely to be more volatile . As such, Bangladeshi policy makers have to be very...conflicts had surfaced in various regions of the world, of which South Asia is the most volatile . According to Paul, due to the prolonged colonial

  17. Sibling rivalry, separation, and change in Austen's Sense and Sensibility.

    Science.gov (United States)

    Fitzpatrick Hanly, Margaret Ann

    2016-08-01

    The paper explores a process of growth represented in the interplay of Jane Austen's characterizations of Marianne and Elinor Dashwood in Sense and Sensibility, approaching the text through the lens of psychoanalytic theories on oedipal sibling rivalry, separation, and processes of change. A close reading of Sense and Sensibility tracks Marianne Dashwood's repudiation of any 'second attachment' as the surface of an unconscious fantasy, denying a rival for the mother's love. A psychoanalytic view contrasts Marianne's lack of separation from her mother, her use of denial and projection, and her near death after losing the man she loves, with her older sister Elinor Dashwood's capacities for depression, reflection, and greater acceptance of loss and separation. The narrative portrays Mrs. Dashwood's identification with and idealization of her daughter Marianne, which contribute to her oedipal sibling 'victory'. In the language and structure of the novel, the projections, identifications, aggressions, and separations (conscious and unconscious) of the sisters in the vicissitudes of their adolescent loves and rivalries constitute a process of growth. Austen's novel brings to life, with the vividness and coherence of great literature, forces and fantasies in oedipal sibling rivalries, inspiring renewed attention to their subtle presence in the transference and countertransference of the psychoanalytic process.

  18. Evaluating relative accommodations in general binocular dysfunctions

    OpenAIRE

    García Muñoz, Ángel; Cacho Martínez, Pilar; Lara Lacarcel, Francisco

    2001-01-01

    Purpose. To examine the relationship between relative accommodation and general binocular disorders and to establish their importance in the diagnosis of these anomalies. Methods. We analyzed data of negative relative accommodation (NRA) and positive relative accommodation (PRA) in 69 patients with nonstrabismic binocular anomalies. Results. Statistical analysis showed that low values of NRA and PRA were not associated with any particular disorder. High values of PRA (>3.50 D) were related to...

  19. Team Learning: Through the Relational Dynamics of Co-operation and Rivalry in Team Communities

    Science.gov (United States)

    Lotz, Maja

    2010-01-01

    This paper explores the constructive links between cooperation, rivalry, and learning within the structure of team communities. Drawing upon social learning theory and qualitative data from case studies conducted in Danish team-based firms, the main purpose is to argue that both cooperation and rivalry are important triggers for mobilizing…

  20. The Effects of Birth Order on Personality Traits and Feelings of Academic Sibling Rivalry

    Science.gov (United States)

    Badger, Julia; Reddy, Peter

    2009-01-01

    The influence of birth order on personality and sibling rivalry is controversial; little research has been conducted into academic sibling rivalry, and none into the connection with personality traits. This study considers the interaction of all three factors. Firstborns (N=22) and lastborns (N=24) completed online personality tests and an…

  1. Binocular form deprivation influences the visual cortex

    Institute of Scientific and Technical Information of China (English)

    Mingming Liu; Chuanhuang Weng; Hanping Xie; Wei Qin

    2012-01-01

    1a-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors are considered to play a crucial role in synaptic plasticity in the developing visual cortex. In this study, we established a rat model of binocular form deprivation by suturing the rat binocular eyelids before eye-opening at postnatal day 14. During development, the decay time of excitatory postsynaptic currents mediated by 1a-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptors of normal rats became longer after eyeopening; however, the decay time did not change significantly in binocular form deprivation rats. The peak value in the normal group became gradually larger with age, but there was no significant change in the binocular form deprivation group. These findings indicate that binocular form deprivation influences the properties of excitatory postsynaptic currents mediated by β-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid receptors in the rat visual cortex around the end of the critical period, indicating that form stimulation is associated with the experience-dependent modification of neuronal synapses in the visual cortex.

  2. An analysis of intergroup rivalry using Ising model and reinforcement learning

    Science.gov (United States)

    Zhao, Feng-Fei; Qin, Zheng; Shao, Zhuo

    2014-01-01

    Modeling of intergroup rivalry can help us better understand economic competitions, political elections and other similar activities. The result of intergroup rivalry depends on the co-evolution of individual behavior within one group and the impact from the rival group. In this paper, we model the rivalry behavior using Ising model. Different from other simulation studies using Ising model, the evolution rules of each individual in our model are not static, but have the ability to learn from historical experience using reinforcement learning technique, which makes the simulation more close to real human behavior. We studied the phase transition in intergroup rivalry and focused on the impact of the degree of social freedom, the personality of group members and the social experience of individuals. The results of computer simulation show that a society with a low degree of social freedom and highly educated, experienced individuals is more likely to be one-sided in intergroup rivalry.

  3. ASEAN and Strategic Rivalry among the Great Powers in Asia

    OpenAIRE

    Fenna Egberink; Frans-Paul van der Putten

    2010-01-01

    This paper looks at ASEAN’s role in the context of the three main bilateral relations among the great powers in Asia: China-US, China-Japan, and China-India. The authors argue that although ASEAN’s influence is limited in terms of geographical reach and its impact on actual security issues, Southeast Asia is potentially an important object of great power rivalry and thus the sub-region is highly relevant to Asian geopolitics. The key question with regard to geopolitical stability is how A...

  4. Is binocular vision worth considering in people with low vision?

    Science.gov (United States)

    Uzdrowska, Marta; Crossland, Michael; Broniarczyk-Loba, Anna

    2014-01-01

    In someone with good vision, binocular vision provides benefits which could not be obtained by monocular viewing only. People with visual impairment often have abnormal binocularity. However, they often use both eyes simultaneously in their everyday activities. Much remains to be known about binocular vision in people with visual impairment. As the binocular status of people with low vision strongly influences their treatment and rehabilitation, it should be evaluated and considered before diagnosis and further recommendations.

  5. Eurasia: The Rivalry of Global Integration Projects

    Directory of Open Access Journals (Sweden)

    Olesia Kobenko

    2016-05-01

    Full Text Available The article reveals the Eurasian integration projects as major drivers of world globalization. Eurasian regionalism seems to be gaining attention in the scientific literature. Under the current political circumstance many regions are accelerating integration and many countries are opting for regional associations as a mechanism to help them overcome the global recession. Moreover, the global political leaders , some developed countries - the U.S., China, and the European Union (EU are interested to set up regional economic blocs such as Eurasian Economic Union (The EEU, the China's project 'One Belt One Road', the U.S's projects - The Trans-Pacific Partnership (TPP and The Transatlantic Trade and Investment Partnership (TTIP. The goal of this paper is to introduce a number of integration initiatives and to analyze the current strategies of Eurasian regionalism.

  6. Future Hegemonic Rivalry Between China and the West?

    Directory of Open Access Journals (Sweden)

    Erich Weede

    1995-08-01

    Full Text Available Currently there is a unipolar distribution of power. The United States reigns supreme. Russia's economic power will remain insufficient to underwrite a renewed attempt to establish global leadership. While the European Community still commands sufficient resources for exercising global leadership, it lacks the political foundation for unitary action. Moreover, the European addiction to the welfare state undermines European competitiveness. Japan is too much of a "trading state" and unlikely to become a first-rate military power, before she is overtaken by China in economic size. So, count Russia, Europe and Japan out as conceivable challengers to United States hegemony. China is the only plausible candidate. Its economic growth rate is nothing less than spectacular. Moreover, the Chinese government seems capable of extracting the necessary resources for waging a hegemonic rivalry from a society that is likely to remain quite poor for at least another generation. There are a number of conceivable scenarios for the emerging American-Chinese relationship. The future will depend on the relative speed of the American decline and the rise of China as well as on the openness of the global economy. The more open the global economy, the better the prospects for rising per capita incomes in China become, the better the prospects for some mellowing or even democratization of the Chinese regime. Only if the West sticks together under American leadership and if creeping capitalism in China leads to creeping democratization later, is hegemonic rivalry likely to remain benign and peaceful.

  7. The case from animal studies for balanced binocular treatment strategies for human amblyopia.

    Science.gov (United States)

    Mitchell, Donald E; Duffy, Kevin R

    2014-03-01

    Although amblyopia typically manifests itself as a monocular condition, its origin has long been linked to unbalanced neural signals from the two eyes during early postnatal development, a view confirmed by studies conducted on animal models in the last 50 years. Despite recognition of its binocular origin, treatment of amblyopia continues to be dominated by a period of patching of the non-amblyopic eye that necessarily hinders binocular co-operation. This review summarizes evidence from three lines of investigation conducted on an animal model of deprivation amblyopia to support the thesis that treatment of amblyopia should instead focus upon procedures that promote and enhance binocular co-operation. First, experiments with mixed daily visual experience in which episodes of abnormal visual input were pitted against normal binocular exposure revealed that short exposures of the latter offset much longer periods of abnormal input to allow normal development of visual acuity in both eyes. Second, experiments on the use of part-time patching revealed that purposeful introduction of episodes of binocular vision each day could be very beneficial. Periods of binocular exposure that represented 30-50% of the daily visual exposure included with daily occlusion of the non-amblyopic could allow recovery of normal vision in the amblyopic eye. Third, very recent experiments demonstrate that a short 10 day period of total darkness can promote very fast and complete recovery of visual acuity in the amblyopic eye of kittens and may represent an example of a class of artificial environments that have similar beneficial effects. Finally, an approach is described to allow timing of events in kitten and human visual system development to be scaled to optimize the ages for therapeutic interventions.

  8. Binocular Vision Function Analysis of 75 Subjects

    Institute of Scientific and Technical Information of China (English)

    Ya-ping Gao; Hai-ying Wang; Xiu-rong Tang; Ying Zhang; Xiao-tong Huo

    2004-01-01

    @@ We randomly chose 75 subjects; 34 men and 41 womenwith an average age of 21 years. Our study method included subject interviews, and evamuination of their refractive and binocular vision functions.We recorded, basic biographical data, medical history, family history, lifestyle factors that relate to their use of vision and history of wearing glasses.

  9. India China Rivalry and Competition in Southeast Asia

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    2011-01-01

    the interrelated variables, inconsistencies and disruptive effects of India's and China’s dramatic rise and insertion into the global political economy and more specifically how this relationship is playing out in Southeast Asia. The paper is divided into five sections. In the introduction the overall historical......The main objective of this paper is to examine the implications of these gradual and in some cases opposing shifts in foreign policy of China and India in Southeast Asia. Both countries are increasingly struggling for a hegemonic position in the developing countries and especially in Southeast Asia...... and strategic relationship between India and China has been briefly outlined. Second section recaps the theoretical considerations while part three focuses on China and India’s encroachment into Southeast Asia. Part four gives examples of competition and rivalry in energy and related resources between the two...

  10. Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2)

    Science.gov (United States)

    2008-05-22

    Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2) A Monograph by MAJ Gary J Morea...NUMBER 4. TITLE AND SUBTITLE Enduring Rivalry in the Philippines and the Application of Amnesty, Reintegration and Reconciliation (AR2) 5c...of force, diplomacy and economic programs that are necessary in initiating and sustaining peace. While the elements of amnesty, reintegration and

  11. Motion Parallax is Asymptotic to Binocular Disparity

    CERN Document Server

    Stroyan, Keith

    2010-01-01

    Researchers especially beginning with (Rogers & Graham, 1982) have noticed important psychophysical and experimental similarities between the neurologically different motion parallax and stereopsis cues. Their quantitative analysis relied primarily on the "disparity equivalence" approximation. In this article we show that retinal motion from lateral translation satisfies a strong ("asymptotic") approximation to binocular disparity. This precise mathematical similarity is also practical in the sense that it applies at normal viewing distances. The approximation is an extension to peripheral vision of (Cormac & Fox's 1985) well-known non-trig central vision approximation for binocular disparity. We hope our simple algebraic formula will be useful in analyzing experiments outside central vision where less precise approximations have led to a number of quantitative errors in the vision literature.

  12. [Aniseikonia reduces binocular summation in the VECP].

    Science.gov (United States)

    Krause, K; Gerding, H; Timmermann, M; Kauffmann, T

    1995-04-01

    The binocular summation effect of human VECP (increase in amplitude from about 4.0 microV to about 5.4 microV) was proved and optimized in 32 subjects. Stimulus parameters: TV steady-state pattern reversal (7.0 Hz); pattern size 1 degree; stimulus contrast 5% (higher stimulus contrasts reduced considerably the selectivity of the binocular summation effect); 96 sweeps averaging (Nicolet Compaq Four); position of electrodes: 10% and 30% above Protuberantia occipitalis externa of nasioninion distance. Aniseikonia of 7 to 52% was generated by means of small Galilei telescopes. Because of comparatively large interindividual variance within the series of subjects, no decrease in binocular VECP amplitude could be demonstrated at an aniseikonia less than 52%. On one woman subject, a significant reduction in amplitude (5% level) at 14%, 26% and 52% aniseikonia was apparent, but not at 7%. Thus, for this subject, it was possible to correlate the results with the clinically known limits of toleration for aniseikonia. This result was confirmed by more than 60% of the subjects in the test group.

  13. Target Image Matching Algorithm Based on Binocular CCD Ranging

    Directory of Open Access Journals (Sweden)

    Dongming Li

    2014-01-01

    Full Text Available This paper proposed target image in a subpixel level matching algorithm for binocular CCD ranging, which is based on the principle of binocular CCD ranging. In the paper, firstly, we introduced the ranging principle of the binocular ranging system and deduced a binocular parallax formula. Secondly, we deduced the algorithm which was named improved cross-correlation matching algorithm and cubic surface fitting algorithm for target images matched, and it could achieve a subpixel level matching for binocular CCD ranging images. Lastly, through experiment we have analyzed and verified the actual CCD ranging images, then analyzed the errors of the experimental results and corrected the formula of calculating system errors. Experimental results showed that the actual measurement accuracy of a target within 3 km was higher than 0.52%, which meet the accuracy requirements of the high precision binocular ranging.

  14. Binocular Vision Problems in Refractive Surgery Patients: Vision Therapy Case Reports

    Directory of Open Access Journals (Sweden)

    Gina Day, OD

    2015-02-01

    Full Text Available Background: Some post-LASIK patients complain of blurry distance vision months after refractive surgery, despite good corneal healing and negligible refractive error. We postulated that perceiving blur in the absence of refractive error or significant monocular aberrations might result from poor binocular control. Binocular vision testing in a series of such patients revealed convergence problems in 83% of cases. Case Reports: We report on 8 patients (average age 37.4 yrs who completed up to 40 sessions of vision therapy (VT, either completely via computer or in a combination of computer orthoptics and office vision therapy. Seven patients had received LASIK; one had PRK. Optometric measurements and symptoms were recorded before and after VT treatment, starting at least 3 months after refractive surgery. Near point of convergence improved in 7 cases following VT, and convergence break and/or recovery improved in 6 cases. Six cases reported symptom reduction, and pre-presbyopic cases tended to improve accommodative facility. The number of binocular functions showing improvement per case correlated with the number of VT sessions completed. Convergence changes were statistically significant when pre-/post-VT data were compared for these cases as a group. Conclusion: Patients complaining of distance blur following refractive surgery may have undiagnosed binocular vision problems. VT incorporating an internet orthoptics component improved convergence ability in the cases reported here, and most patients reported symptomatic relief.

  15. Maintaining a suite of binocular facility instruments at the Large Binocular Telescope

    Science.gov (United States)

    Reynolds, Robert O.; Morris, John; Power, Jennifer; Howard, James; Riedl, James; Solheid, Elliott; Wagner, R. M.; Veillet, Christian

    2014-08-01

    Facility Instruments at the Large Binocular Telescope (LBT) include the Large Binocular Camera (LBC), a pair of wide-field imagers at the prime focus, the LUCIFER (or LUCI) near-infrared imager and spectrograph pair, and the Multi-Object Double Spectrograph (MODS), a pair of long-slit spectrographs. The disciplines involved in instrument support are reviewed, as well as scheduling of support personnel. A computerized system for instrument maintenance scheduling and spare parts inventory is described. Instrument problems are tracked via an online reporting system, and statistics on types of instrument problems are discussed, as well as applicability of the system to troubleshooting.

  16. Automated Detection of Ocular Alignment with Binocular Retinal Birefringence Scanning

    Science.gov (United States)

    Hunter, David G.; Shah, Ankoor S.; Sau, Soma; Nassif, Deborah; Guyton, David L.

    2003-06-01

    We previously developed a retinal birefringence scanning (RBS) device to detect eye fixation. The purpose of this study was to determine whether a new binocular RBS (BRBS) instrument can detect simultaneous fixation of both eyes. Control (nonmyopic and myopic) and strabismic subjects were studied by use of BRBS at a fixation distance of 45 cm. Binocularity (the percentage of measurements with bilateral fixation) was determined from the BRBS output. All nonstrabismic subjects with good quality signals had binocularity >75%. Binocularity averaged 5% in four subjects with strabismus (range of 0 -20%). BRBS may potentially be used to screen individuals for abnormal eye alignment.

  17. Assessing Binocular Interaction in Amblyopia and Its Clinical Feasibility

    OpenAIRE

    MiYoung Kwon; Zhong-Lin Lu; Alexandra Miller; Melanie Kazlas; Hunter, David G.; Peter J. Bex

    2014-01-01

    PURPOSE: To measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic. METHODS: Binocular interaction was assessed in subjects with strabismic amblyopia (n = 7), anisometropic amblyopia (n = 6), strabismus without amblyopia (n = 15) and normal vision (n = 40). Binocular interaction was measured with a dichoptic phase matching task in which subjects matched the position of a binocular probe t...

  18. Usefulness influences visual appearance in motion transparency depth rivalry.

    Science.gov (United States)

    Chopin, Adrien; Mamassian, Pascal

    2011-06-24

    Two sets of dots moving in opposite directions are usually seen as two transparent surfaces. Deciding which surface is in front of the other is bistable and observers exhibit strong biases to see one particular motion direction in front. Surprisingly, biases are dependent on stimulus orientation in a persistent, idiosyncratic, and irrelevant manner. We investigated here whether this preferred direction is arbitrarily fixed or can instead be updated from the context. Observers performed two tasks alternately. One task was to report the surface seen in front in a transparent motion stimulus. The other task was a visual search for a slow dot. Unknown to the observers, we systematically paired the target dot with one surface direction in an attempt to make that surface appear preferentially in front. This manipulation was sufficient to change the observer's preferred direction for the surface seen in front. Attentional explanations did not account for the results. Observers modified their idiosyncratic preference in motion transparency depth rivalry only because it was useful to perform well in an auxiliary task.

  19. [Binocular vision after treatment of retinal detachment].

    Science.gov (United States)

    Maksymowicz, Małgorzata; Raczyńska, Krystyna; Maksymowicz, Jarosław

    2003-01-01

    The study covered 79 patients after treatment of retinal detachment. Double vision, strabismus and disturbances of eyeballs motility were found. Up to 12 months after intervention, the deterioration of binocular vision was observed in 48.28 to 89.66% of patients, depending on the method used. The majority of disturbances were observed during the first 3 months with tendency to gradual subsidence during consecutive 9 months. A patient, after treatment of retinal detachment, can be qualified to return to work where stereopsis is needed under condition that ophthalmologic examination is done every three months during the first year after operation and than once a year.

  20. Narcissistic admiration and rivalry: disentangling the bright and dark sides of narcissism.

    Science.gov (United States)

    Back, Mitja D; Küfner, Albrecht C P; Dufner, Michael; Gerlach, Tanja M; Rauthmann, John F; Denissen, Jaap J A

    2013-12-01

    We present a process model that distinguishes 2 dimensions of narcissism: admiration and rivalry. We propose that narcissists' overarching goal of maintaining a grandiose self is pursued by 2 separate pathways, characterized by distinct cognitive, affective-motivational, and behavioral processes. In a set of 7 studies, we validated this 2-dimensional model using the newly developed Narcissistic Admiration and Rivalry Questionnaire (NARQ). We showed that narcissistic admiration and rivalry are positively correlated dimensions, yet they have markedly different nomological networks and distinct intra- and interpersonal consequences. The NARQ showed the hypothesized 2-dimensional multifaceted structure as well as very good internal consistencies (Study 1, N = 953), stabilities (Study 2, N = 93), and self-other agreements (Study 3, N = 96). Narcissistic admiration and rivalry showed unique relations to the Narcissistic Personality Inventory (NPI), the Big Five, self-esteem, pathological narcissism, and other narcissism-related traits like Machiavellianism, psychopathy, self-enhancement, and impulsivity (Study 4, Ns = 510-1,814). Despite the positive relation between admiration and rivalry, the 2 differentially predicted general interpersonal orientations and reactions to transgressions in friendships and romantic relationships (Study 5, N = 1,085), interpersonal perceptions during group interactions (Study 6, N = 202), and observed behaviors in experimental observations (Study 7, N = 96). For all studies, the NARQ outperformed the standard measure of narcissism, the NPI, in predicting outcome measures. Results underscore the utility of a 2-dimensional conceptualization and measurement of narcissism.

  1. The Binocular Advantage in Visuomotor Tasks Involving Tools

    Directory of Open Access Journals (Sweden)

    Jenny C. A. Read

    2013-04-01

    Full Text Available We compared performance on three manual-dexterity tasks under monocular and binocular viewing. The tasks were the standard Morrisby Fine Dexterity Test, using forceps to manipulate the items, a modified version of the Morrisby test using fingers, and a “buzz-wire” task in which subjects had to guide a wire hoop around a 3D track without bringing the hoop into contact with the track. In all three tasks, performance was better for binocular viewing. The extent of the binocular advantage in individuals did not correlate significantly with their stereoacuity measured on the Randot test. However, the extent of the binocular advantage depended strongly on the task. It was weak when fingers were used on the Morrisby task, stronger with forceps, and extremely strong on the buzz-wire task (fivefold increase in error rate with monocular viewing. We suggest that the 3D buzz-wire game is particularly suitable for assessing binocularly based dexterity.

  2. The binocular advantage in visuomotor tasks involving tools.

    Science.gov (United States)

    Read, Jenny C A; Begum, Shah Farzana; McDonald, Alice; Trowbridge, Jack

    2013-01-01

    We compared performance on three manual-dexterity tasks under monocular and binocular viewing. The tasks were the standard Morrisby Fine Dexterity Test, using forceps to manipulate the items, a modified version of the Morrisby test using fingers, and a "buzz-wire" task in which subjects had to guide a wire hoop around a 3D track without bringing the hoop into contact with the track. In all three tasks, performance was better for binocular viewing. The extent of the binocular advantage in individuals did not correlate significantly with their stereoacuity measured on the Randot test. However, the extent of the binocular advantage depended strongly on the task. It was weak when fingers were used on the Morrisby task, stronger with forceps, and extremely strong on the buzz-wire task (fivefold increase in error rate with monocular viewing). We suggest that the 3D buzz-wire game is particularly suitable for assessing binocularly based dexterity.

  3. Assessing binocular interaction in amblyopia and its clinical feasibility.

    Directory of Open Access Journals (Sweden)

    MiYoung Kwon

    Full Text Available PURPOSE: To measure binocular interaction in amblyopes using a rapid and patient-friendly computer-based method, and to test the feasibility of the assessment in the clinic. METHODS: Binocular interaction was assessed in subjects with strabismic amblyopia (n = 7, anisometropic amblyopia (n = 6, strabismus without amblyopia (n = 15 and normal vision (n = 40. Binocular interaction was measured with a dichoptic phase matching task in which subjects matched the position of a binocular probe to the cyclopean perceived phase of a dichoptic pair of gratings whose contrast ratios were systematically varied. The resulting effective contrast ratio of the weak eye was taken as an indicator of interocular imbalance. Testing was performed in an ophthalmology clinic under 8 mins. We examined the relationships between our binocular interaction measure and standard clinical measures indicating abnormal binocularity such as interocular acuity difference and stereoacuity. The test-retest reliability of the testing method was also evaluated. RESULTS: Compared to normally-sighted controls, amblyopes exhibited significantly reduced effective contrast (∼20% of the weak eye, suggesting a higher contrast requirement for the amblyopic eye compared to the fellow eye. We found that the effective contrast ratio of the weak eye covaried with standard clincal measures of binocular vision. Our results showed that there was a high correlation between the 1st and 2nd measurements (r = 0.94, p<0.001 but without any significant bias between the two. CONCLUSIONS: Our findings demonstrate that abnormal binocular interaction can be reliably captured by measuring the effective contrast ratio of the weak eye and quantitative assessment of binocular interaction is a quick and simple test that can be performed in the clinic. We believe that reliable and timely assessment of deficits in a binocular interaction may improve detection and treatment of amblyopia.

  4. RIVALS OF A KIND: the Anglo-American Commercial Aviation Rivalry, 1939-45

    Directory of Open Access Journals (Sweden)

    Erik Benson

    2008-01-01

    Full Text Available Before World War II, the British and Americans had been fierce rivals in the international airline business. Their wartime alliance muted this rivalry, yet it still simmered, manifesting itself in a variety of global incidents and issues. As the war progressed, the Americans gained tremendous advantages in the field, raising British fears about American dominance of the world’s airways. In turn, American policymakers worried about British control of key areas of the world. The mutual suspicion grew, and the rivalry resurfaced in the last months of the war. The conflict had merely subsumed the differences, and made the two powers rivals of a kind.

  5. Protection against deprivation amblyopia depends on relative not absolute daily binocular exposure.

    Science.gov (United States)

    Mitchell, Donald E; Sengpiel, Frank; Hamilton, David C; Schwarzkopf, D Samuel; Kennie, Jan

    2011-06-16

    Short daily periods of binocular exposure (BE) can offset longer single daily episodes of monocular exposure (ME) to prevent the development of deprivation amblyopia. To determine whether the outcome depended upon an absolute daily amount of BE or its proportion of the daily visual exposure, daily mixed visual input of 3 different durations (3.5, 7, or 12 h) was imposed on 3 cohorts of kittens. Measurements of the visual acuity of the deprived eye at the end of mixed daily visual input revealed that the acuity of the deprived eye developed to normal values so long as the proportion of the total exposure that was binocular was 30% or more. By contrast, the development of functional ocular dominance domains in V1 revealed by optical imaging suggests that normal domains emerge with a fixed amount of daily binocular exposure. The latter result is consistent with the effects of any daily period of ME, or BE, or both, effectively saturating with a small dose so that the effects of ME of any length can be offset by a short period of BE. The different result for vision may reflect neural events at higher and/or multiple levels in the visual pathway.

  6. Fisiologia da visão binocular Physiology of binocular vision

    Directory of Open Access Journals (Sweden)

    Harley E. A. Bicas

    2004-02-01

    Full Text Available A visão binocular de seres humanos resulta da superposição quase completa dos campos visuais de cada olho, o que suscita discriminação perceptual de localizações espaciais de objetos relativamente ao observador (localização egocêntrica bem mais fina (estereopsia, mas isso ocorre em, apenas, uma faixa muito estreita (o horóptero. Aquém e além dela, acham-se presentes diplopia e confusão, sendo necessária supressão fisiológica (cortical para evitá-las. Analisa-se a geometria do horóptero e suas implicações fisiológicas (o desvio de Hillebrand, a partição de Kundt, a área de Panum, assim como aspectos clínicos da visão binocular normal (percepção simultânea, fusão, visão estereoscópica e de adaptações a seus estados afetados (supressão patológica, ambliopia, correspondência visual anômala.The binocular vision of human beings is given by the almost complete superimposition of the monocular visual fields, which allows a finer perceptual discrimination of the egocentric localization of objects in space (stereopsis but only within a very narrow band (the horopter. Before and beyond it, diplopia and confusion are present, so that a physiologic (cortical suppression is necessary to avoid them to become conscious. The geometry of the horopter and its physiologic implications (Hillebrand's deviation, Kundt's partition, Panum's area, stereoscopic vision are analyzed, as well as some clinical aspects of the normal binocular vision (simultaneous perception, fusion, stereoscopic vision and of adaptations to abnormal states (pathologic suppression, amblyopia, abnormal retinal correspondence.

  7. 3D Motion Parameters Determination Based on Binocular Sequence Images

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Exactly capturing three dimensional (3D) motion information of an object is an essential and important task in computer vision, and is also one of the most difficult problems. In this paper, a binocular vision system and a method for determining 3D motion parameters of an object from binocular sequence images are introduced. The main steps include camera calibration, the matching of motion and stereo images, 3D feature point correspondences and resolving the motion parameters. Finally, the experimental results of acquiring the motion parameters of the objects with uniform velocity and acceleration in the straight line based on the real binocular sequence images by the mentioned method are presented.

  8. Trinocular Calibration Method Based on Binocular Calibration

    Directory of Open Access Journals (Sweden)

    CAO Dan-Dan

    2012-10-01

    Full Text Available In order to solve the self-occlusion problem in plane-based multi-camera calibration system and expand the measurement range, a tri-camera vision system based on binocular calibration is proposed. The three cameras are grouped into two pairs, while the public camera is taken as the reference to build the global coordinate. By calibration of the measured absolute distance and the true absolute distance, global calibration is realized. The MRE (mean relative error of the global calibration of the two camera pairs in the experiments can be as low as 0.277% and 0.328% respectively. Experiment results show that this method is feasible, simple and effective, and has high precision.

  9. Competition with and without priority control: linking rivalry to attention through winner-take-all networks with memory.

    Science.gov (United States)

    Marx, Svenja; Gruenhage, Gina; Walper, Daniel; Rutishauser, Ueli; Einhäuser, Wolfgang

    2015-03-01

    Competition is ubiquitous in perception. For example, items in the visual field compete for processing resources, and attention controls their priority (biased competition). The inevitable ambiguity in the interpretation of sensory signals yields another form of competition: distinct perceptual interpretations compete for access to awareness. Rivalry, where two equally likely percepts compete for dominance, explicates the latter form of competition. Building upon the similarity between attention and rivalry, we propose to model rivalry by a generic competitive circuit that is widely used in the attention literature-a winner-take-all (WTA) network. Specifically, we show that a network of two coupled WTA circuits replicates three common hallmarks of rivalry: the distribution of dominance durations, their dependence on input strength ("Levelt's propositions"), and the effects of stimulus removal (blanking). This model introduces a form of memory by forming discrete states and explains experimental data better than competitive models of rivalry without memory. This result supports the crucial role of memory in rivalry specifically and in competitive processes in general. Our approach unifies the seemingly distinct phenomena of rivalry, memory, and attention in a single model with competition as the common underlying principle.

  10. Binocular vision in amblyopia: structure, suppression and plasticity.

    Science.gov (United States)

    Hess, Robert F; Thompson, Benjamin; Baker, Daniel H

    2014-03-01

    The amblyopic visual system was once considered to be structurally monocular. However, it now evident that the capacity for binocular vision is present in many observers with amblyopia. This has led to new techniques for quantifying suppression that have provided insights into the relationship between suppression and the monocular and binocular visual deficits experienced by amblyopes. Furthermore, new treatments are emerging that directly target suppressive interactions within the visual cortex and, on the basis of initial data, appear to improve both binocular and monocular visual function, even in adults with amblyopia. The aim of this review is to provide an overview of recent studies that have investigated the structure, measurement and treatment of binocular vision in observers with strabismic, anisometropic and mixed amblyopia.

  11. [Stereoscopic vision evaluation in patients after binocular implantation of different intraocular lens models].

    Science.gov (United States)

    Chuprov, A D; Ivonin, K S; Zamyrov, A A; Kudriavtseva, Iu V

    2013-01-01

    Stereoscopic vision in patients after binocular implantation of different intraocular lens (IOL) models was evaluated. 24 patients (48 eyes) after cataract surgery were enrolled in the study. Follow-up was 12 months. 1st group included 9 patients (18 eyes) after cataract surgery and implantation of Russian trifocal refractive-diffractive IOL MIOL-Record 3. 2nd group included 6 patients (12 eyes) after cataract surgery and implantation of Russian bifocal refractive-diffractive IOL MIOL-Accord 3. 3rd group included 9 patients (12 eyes) after cataract surgery and implantation of Russian monofocal IOL MIOL-2. Stereoscopic vision was evaluated using "Stereopsis" software with 25 cm distance 1 week, 1, 3, 6, 12 months after surgery. Clinical study did not reveal any statistically significant difference between groups (trifocal, bifocal and monofocal IOLs) in terms of stereopsis (p > 0.05). Stereopsis parameters were stable during the whole follow-up period. Clinical study evaluating stereoscopic vision in patients after binocular implantation of different IOLs shows that patients with binocular implantation of bifocal and trifocal IOLs have good and stable stereoscopic vision parameters after surgery at least equal to patients with monofocal IOLs.

  12. Binocular Refraction in Patients with Age-Related Macular Degeneration

    OpenAIRE

    Skrbek, Matěj

    2013-01-01

    We’ve been finding possible association of central vision damage with binocular vision disorders in our clients suffering from age-related macular degeneration (ARMD), but whose visual acuity still allowed us to examine their binocular vision. Our findings show that there is a significant number of patients with heterophoria in horizontal, as well as vertical direction. The clients rate the vision with prismatic correction as more comfortable, clearer and long-term tolerable. Getting used ...

  13. Perceptual constancy in judgments of egocentric distance: prevailing binocular information

    Directory of Open Access Journals (Sweden)

    Matsushima Elton H.

    2003-01-01

    Full Text Available Binocular cues were considered the prevailing information on specifying depth since the beginning of vision research. In the present study, two perceptual responses, the classical verbal report and a more recent method, open-loop walking, were used to assess the role of binocular information for egocentric distance perception. In two cue conditions environments, full- and reduced-cue, observers judged and walked egocentric distances of stimuli presented at eye-level, under binocular or monocular viewing. Results indicated perceptual constancy for open-loop walking and binocular responses, as well as poor performances under strong degradation on visual information (reduced-cue under monocular viewing, thus presenting evidence to support the fundamental role of binocular information on perception of egocentric distances. Besides that, visually directed actions could be adequate measures of perceived distance, with a better reliability than verbal report, since they were quite free of intrusion of inferential processes and perceptual tendencies. In addition, reduced head movements, side-to-side as well as back and forth deflexion movements, could have contributed to a near perfect coupling between binocular disparity information and open-loop walking responses.

  14. Cortical conditions for fused binocular vision.

    Science.gov (United States)

    Burns, B D; Pritchard, R

    1968-07-01

    1. The behaviour of twenty-six single neurones has been studied in the visual cerebral cortex of the cat's neurologically isolated and unanaesthetized forebrain. In a separate series of experiments binocular vision was investigated in five human subjects.2. Units in the cat's brain were excited by two straight, light-dark edges, projected independently, one upon each retina; these edges were given identical, artificial saccadic movements. The average response of neurones was measured from the post-stimulus-histogram (P.S.H.), which provided the probability of unit-discharge at various times after the pattern movement.3. A district within either eye-field could usually be found, such that the saccadic movements of edges passing through this part of the field, caused maximal responses; this part of each field is termed the ;representative district'. The most exciting orientations of the stimulating patterns were similar for both eyes. A cell excited by similarly oriented patterns, ;aligned' through the representative districts for each eye, exhibited dramatic spatial summation. Mutual inhibition between retinal inputs was never seen.4. The response of cortical neurones to such aligned patterns was always greater than that when one pattern was misaligned by displacement in either direction from its representative district.5. When the pattern in one eye was inverted, the cell gave less response to aligned than to misaligned patterns.6. Human subjects, viewing similar inverted patterns through a mirror stereoscope, could only obtain stable fusion with a 5 min arc misalignment of the optic axes.7. In other experiments, one eye of each subject was presented with a white rectangular bar upon a black background, while the other eye was excited by a similar black bar upon a white background. Stable fusion was reported, providing percepts of either one single low contrast bar or two neighbouring bars of high contrast. There was a range of relative pattern positions over which

  15. Development of binocular vision in the kitten's striate cortex.

    Science.gov (United States)

    Freeman, R D; Ohzawa, I

    1992-12-01

    Studies of the development and plasticity of the visual pathway are well documented, but a basic question remains open: what is the physiological status of the system prior to extensive visual experience? Somewhat conflicting answers have been put forward, and in a major area, binocular vision, reports have ranged from severe immaturity to well-developed maturity. This is an important question to resolve since binocular cells in the visual cortex are thought to be the neural substrate for stereoscopic depth perception. We have addressed this question by recording from single cells in the striate cortex of kittens at postnatal ages 2, 3, and 4 weeks and from adults for comparison. Gratings with sinusoidal luminance distribution are presented to left, right, or both eyes. For each cell, we determine optimal values for orientation and spatial frequency. Relative phase (retinal disparity) is then varied in a dichoptic sequence so that binocular interaction may be studied. Results are as follows. In the normal adult, we have shown in previous work that most binocular interaction in the visual cortex can be accounted for on the basis of linear summation. Results from 3 and 4 week postnatal kittens are closely similar to those from adults. All types of binocular interaction found in adults are present in kittens. This includes phase-specific and non-phase-specific suppression or facilitation. Furthermore, monocular and binocular tuning characteristics are comparable in kittens and adults. The clear changes that occur with age are optimal spatial frequencies and peak responses. In addition, at 2 weeks, there is a substantially higher proportion of monocular cells compared to other ages and correspondingly, lower relative numbers of cells that exhibit phase-specific or suppressive binocular interactions. From increases in optimal spatial frequency and interpupillary distance with age, we calculated predicted changes in binocular disparity thresholds (stereo acuity) with age

  16. Maximum saliency bias in binocular fusion

    Science.gov (United States)

    Lu, Yuhao; Stafford, Tom; Fox, Charles

    2016-07-01

    Subjective experience at any instant consists of a single ("unitary"), coherent interpretation of sense data rather than a "Bayesian blur" of alternatives. However, computation of Bayes-optimal actions has no role for unitary perception, instead being required to integrate over every possible action-percept pair to maximise expected utility. So what is the role of unitary coherent percepts, and how are they computed? Recent work provided objective evidence for non-Bayes-optimal, unitary coherent, perception and action in humans; and further suggested that the percept selected is not the maximum a posteriori percept but is instead affected by utility. The present study uses a binocular fusion task first to reproduce the same effect in a new domain, and second, to test multiple hypotheses about exactly how utility may affect the percept. After accounting for high experimental noise, it finds that both Bayes optimality (maximise expected utility) and the previously proposed maximum-utility hypothesis are outperformed in fitting the data by a modified maximum-salience hypothesis, using unsigned utility magnitudes in place of signed utilities in the bias function.

  17. The performance of the blue prime focus Large Binocular Camera at the Large Binocular Telescope

    CERN Document Server

    Giallongo, E; Grazian, A; Baruffolo, A; Beccari, G; De Santis, C; Diolaiti, E; Di Paola, A; Farinato, J; Fontana, A; Gallozzi, S; Gasparo, F; Gentile, G; Green, R; Hill, J; Kuhn, O; Pasian, F; Pedichini, F; Radovich, M; Salinari, P; Smareglia, R; Speziali, R; Testa, V; Thompson, D; Vernet, E; Wagner, R M

    2008-01-01

    We present the characteristics and some early scientific results of the first instrument at the Large Binocular Telescope (LBT), the Large Binocular Camera (LBC). Each LBT telescope unit will be equipped with similar prime focus cameras. The blue channel is optimized for imaging in the UV-B bands, the red channel is optimized for imaging in the VRIz bands. The corrected field of view for each camera is about 30 arcmin of diameter and the chip area is equivalent to a 23x23 arcmin2 field. In this paper we also present the commissioning results of the blue channel. Several measurements have been obtained to assess the technical and scientific performance of the blue camera. Among others, astrometric distortion, flat fielding, ghosts and photometric calibration. These measurements have been used as input to a data reduction pipeline applied to the science data selected for the commissioning of the instrument. The measurements obtained during the commissioning showed that the technical performance of the Blue came...

  18. Multi-coloured stereograms unveil two binocular colour mechanisms in human vision.

    Science.gov (United States)

    Erkelens, Casper J; van Ee, Raymond

    2002-04-01

    Two different colours, one presented to one eye and the other presented to the other eye, often create the impression of a third colour. This percept is known as binocular colour mixture. Here we use coloured stereograms to study binocular colour appearance. Vivid pastel colours are induced in monocular, achromatic patches, if these are placed in stereograms whose left and right images differ in colour. The build-up of the colours is slow and takes tens of seconds or even minutes in certain individuals. The induced colours remain visible during monocular viewing of the patch and decay gradually. The same colours are induced irrespective of whether the patches are placed in fusible or rivalrous stereograms. We show that these colour effects cannot be induced by monocular colour mechanisms, either alone or in combination with binocular colour mixing. We suggest that the colours are induced by a binocular feedback mechanism, which reduces colour differences between the colour appearances of two monocular images. Induced colours are not observed if the achromatic patches are binocular. However, induced colours are apparent if one switches to monocular viewing after prolonged binocular viewing of the binocular patches. This aftereffect suggests that binocular colour induction acts on the monocular representations of binocular images. We suggest that during binocular viewing the fast process of binocular colour mixing masks the changes in colour appearance produced by the much slower process of binocular colour induction.

  19. Binocular refraction in patients with age-related macular degeneration.

    Science.gov (United States)

    Skrbek, Matej

    2013-04-01

    We've been finding possible association of central vision damage with binocular vision disorders in our clients suffering from age-related macular degeneration (ARMD), but whose visual acuity still allowed us to examine their binocular vision. Our findings show that there is a significant number of patients with heterophoria in horizontal, as well as vertical direction. The clients rate the vision with prismatic correction as more comfortable, clearer and long-term tolerable. Getting used to prismatic correction was spontaneous and non-problematic. Based on these results we expect to find possibly the most effective rehabilitation of vision in patients suffering from ARMD.

  20. The last will and testament in literature: rupture, rivalry, and sometimes rapprochement from Middlemarch to Lemony Snicket.

    Science.gov (United States)

    Stone, Elizabeth

    2008-12-01

    Although the psychological literature on the last will and testament is sparse, authors of fiction and memoir have filled the gap, writing in rich detail about the impact of wills on families. Henry James, George Eliot, J. R. Ackerley, and others reveal that a will is not only a legal document but a microcosm of family life: a coded and non-negotiable message from the will's writer to its intended readers, the heirs, delivered at a stressful time and driving home the truth that options for discussion between testator and heirs are now gone, all factors which may intensify the ambivalence of grief and stall its resolution. Among the problems the authors chronicle: reinvigorated sibling rivalries, vindictive testators, and the revelation of traumatic family secrets. Writers also demonstrate how contemporary social factors, such as divorce, second families, and geographic distance between family members, may complicate wills and ensuing family relations. Exemplary wills, or will-like documents, appear in fiction by Maria Katzenbach and Marilynne Robinson, allowing the living to make rapprochements with the dead, and pointing to testamentary strategies clinicians might develop to lead to a resolution of grief. The depth of these writers' accounts allows clinicians to imagine points at which they might productively intervene in matters pertaining to a will.

  1. Visual comfort of binocular and 3D displays

    NARCIS (Netherlands)

    Kooi, F.L.; Toet, A.

    2004-01-01

    Imperfections in binocular image pairs can cause serious viewing discomfort. For example, in stereo vision systems eye strain is caused by unintentional mismatches between the left and right eye images (stereo imperfections). Head-mounted displays can induce eye strain due to optical misalignments.

  2. Stability of binocular depth perception with moving head and eyes

    NARCIS (Netherlands)

    Ee, R. van; Erkelens, Casper J.

    2001-01-01

    We systematically analyse the binocular disparity field under various eye, head and stimulus positions and orientations. From the literature we know that certain classes of disparity which involve the entire disparity field (such as those caused by horizontal lateral shift, differential rotation, ho

  3. Design of Vertically Aligned Binocular Omnistereo Vision Sensor

    Directory of Open Access Journals (Sweden)

    Wang Qing

    2010-01-01

    Full Text Available Abstract Catadioptric omnidirectional vision sensor (ODVS with a fixed single view point is a fast and reliable single panoramic visual information acquisition equipment. This paper presents a new type of binocular stereo ODVS which composes of two ODVS with the same parameters. The single view point of each ODVS is fixed on the same axis with face-to-face, back-to-back, and faceto- back configuration; the single view point design is implemented by catadioptric technology such as the hyperboloid, constant angular resolution, and constant vertical resolution. The catadioptric mirror design uses the method of increasing the resolution of the view field and the scope of the image in the vertical direction. The binocular stereo ODVS arranged in vertical is designed spherical, cylindrical surfaces and rectangular plane coordinate system for 3D calculations. Using the collinearity of two view points, the binocular stereo ODVS is able to easily align the azimuth, while the camera calibration, feature points match, and other cumbersome steps have been simplified. The experiment results show that the proposed design of binocular stereo ODVS can solve the epipolar constraint problems effectively, match three-dimensional image feature points rapidly, and reduce the complexity of three-dimensional measurement considerably.

  4. [Study and application of "binocular aniseikonia test chart"].

    Science.gov (United States)

    Liu, A N; Yan, S M

    1994-09-01

    With the help of this chart, the image incongruity of simultaneous perception, fusion and stereoscopic vision can be precisely determined. It can objectively evaluate the binocular visual function and possesses important significance for the diagnosis and treatment of anisometropia, amblyopia, strabismus and visual fatigue.

  5. Stereopsis and disparity vergence in monkeys with subnormal binocular vision.

    Science.gov (United States)

    Harwerth, R S; Smith, E L; Crawford, M L; von Noorden, G K

    1997-02-01

    The surgical treatment for strabismus in infants generally results in microtropia or subnormal binocular vision. Although the clinical characteristics of these conditions are well established, there are important questions about the mechanisms of binocular vision in these patients that can best be investigated in an appropriate animal model. In the present psychophysical investigations, spatial frequency response functions for disparity-induced fusional vergence and for local stereopsis were studied in macaque monkeys, who demonstrated many of the major visual characteristics of patients whose eyes were surgically aligned during infancy. In six rhesus monkeys, unilateral esotropia was surgically induced at various ages (30-184 days of age). However, over the next 12 months, all of the monkeys recovered normal eye alignment. Behavioral measurements at 4-6 years of age showed that the monkeys' prism-induced fusional vergence responses were indistinguishable from those of control monkeys or humans with normal binocular vision. Investigations of stereo-depth discrimination demonstrated that each of the experimental monkeys also had stereoscopic vision, but their stereoacuities varied from being essentially normal to severely stereo-deficient. The degree of stereo-deficiency was not related to the age at which surgical esotropia was induced, or to the presence or absence of amblyopia, and was not dependent on the spatial frequency of the test stimulus. Altogether, these experiments demonstrate that a temporary, early esotropia can affect the binocular disparity responses of motor and sensory components of binocular vision differently, probably because of different sensitive periods of development for the two components.

  6. Uranium wars the scientific rivalry that created the nuclear age

    CERN Document Server

    Aczel, Amir D

    2009-01-01

    The author of Fermat's Last Theorem tackles the cause of the last century's most destructive event - the discovery of nuclear power. Aczel presents the fascinating story of the rival scientists who uncovered uranium's potential and reveals the ongoing tale of an element that is never far from today's headlines.

  7. Holmes and Horrax (1919) revisited: impaired binocular fusion as a cause of "flat vision" after right parietal brain damage - a case study.

    Science.gov (United States)

    Schaadt, Anna-Katharina; Brandt, Stephan A; Kraft, Antje; Kerkhoff, Georg

    2015-03-01

    The complete loss of binocular depth perception ("flat vision") was first thoroughly described by Holmes and Horrax (1919), and has been occasionally reported thereafter in patients with bilateral posterior-parietal lesions. Though partial spontaneous recovery occurred in some cases, the precise cause(s) of this condition remained obscure for almost a century. Here, we describe a unique patient (EH) with a large right-sided occipito-parietal hemorrhage showing a complete loss of visual depth perception for several months post-stroke. EH could well simultaneously describe multiple visual objects - hence did not show simultanagnosia - but at the same time was completely unable to estimate their distance from him. In every 3-D visual scene objects appeared equidistant to him, thus experiencing a total loss of depth perception ("flat vision"). Neurovisual assessments revealed normal functions of the eyes. EH showed bilateral lower field loss and a severely impaired binocular convergent fusion, but preserved stereopsis. Perceptual re-training of binocular fusion resulted in a progressive and finally complete recovery of objective binocular fusion values and subjective binocular depth perception in a far-to-near-space, gradient-like manner. In parallel, visual depth estimation of relative distances improved, whereas stereopsis remained unchanged. Our results show that a complete loss of 3-D depth perception can result from an isolated impairment in binocular fusion. On a neuroanatomical level, this connection could be explained by a selective lesion of area V6/V6A in the medial occipito-parietal cortex that has been associated with the integration of visual space coordinates and sustained eye-positions into a cyclopean visual 3-D percept.

  8. Narcissism and romantic relationships: The differential impact of narcissistic admiration and rivalry.

    Science.gov (United States)

    Wurst, Stefanie N; Gerlach, Tanja M; Dufner, Michael; Rauthmann, John F; Grosz, Michael P; Küfner, Albrecht C P; Denissen, Jaap J A; Back, Mitja D

    2017-02-01

    Narcissism is known to be related to romantic success in short-term contexts (dating, early stage relationships) but also to problems in long-term committed relationships. We propose that these diverging romantic outcomes of narcissism can be explained by differential associations with agentic versus antagonistic dimensions of grandiose narcissism: Narcissistic Admiration and Rivalry. Both dimensions serve the central narcissistic goal of gaining and maintaining a grandiose self-view, but do so by different processes: Admiration is characterized by the tendency to promote the positivity of one's self-view by seeking social admiration (assertive self-enhancement). Rivalry is characterized by the tendency to protect oneself from a negative self-view by derogating others (antagonistic self-protection). Across 7 studies (total N = 3,560) using diverse measures and methodological approaches (self-, peer, and partner reports, as well as interpersonal perception measures in video-based studies, face-to-face laboratory encounters, and online surveys), we show that the short-term romantic appeal associated with narcissism is primarily attributable to the dimension of Admiration, whereas the long-term romantic problems associated with narcissism are primarily attributable to the dimension of Rivalry. These results highlight the utility of a 2-dimensional reconceptualization of grandiose narcissism for explaining its heterogeneous romantic outcomes. The findings further underscore the idea that different facets of personality traits might impact different aspects of romantic relationship quality, depending on the stage of the relationship. Such a more nuanced view increases the predictive validity of personality traits in social relationship research. (PsycINFO Database Record

  9. A deep Large Binocular Telescope view of the Canes Venatici I dwarf galaxy

    CERN Document Server

    Martin, Nicolas F; De Jong, Jelte T A; Rix, Hans-Walter; Bell, Eric F; Sand, David J; Hill, John M; Kochanek, Christopher S; Thompson, David; Burwitz, Vadim; Giallongo, Emanuele; Ragazzoni, Roberto; Diolaiti, Emiliano; Gasparo, Federico; Grazian, Andrea; Pedichini, Fernando; Bechtold, Jill

    2007-01-01

    We present the first deep color-magnitude diagram of the Canes Venatici I (CVnI) dwarf galaxy from observations with the wide field Large Binocular Camera of the Large Binocular Telescope. Reaching down to the main-sequence turnoff of the oldest stars, it reveals a dichotomy in the stellar populations of CVnI: it harbors an old (>~ 10 Gyr), metal-poor ([Fe/H] ~ -2.0) and spatially extended population along with a much younger (~1.4-2.0 Gyr), 0.5 dex more metal-rich, and spatially more concentrated population. These young stars are also offset by ~100 pc to the East of the center of the galaxy. The data suggest that this young population should be identified with the kinematically cold stellar component found by Ibata et al. (2006). CVnI therefore follows the behavior of the other remote MW dwarf spheroidals which all contain intermediate age and/or young populations: a complex star formation history is possible in extremely low-mass galaxies.

  10. Binocular disparity as an explanation for the moon illusion

    CERN Document Server

    Antonides, Joseph

    2013-01-01

    We present another explanation for the moon illusion, in which the moon looks larger near the horizon than near the zenith. In our model, the sky is considered a spatially contiguous and geometrically smooth surface. When an object (like the moon) breaks the contiguity of the surface, humans perceive an occlusion of the surface rather than an object appearing through a hole. Binocular vision dictates that the moon is distant, but this perception model dictates that the moon is closer than the sky. To solve the dilemma, the brain distorts the projections of the moon to increase the binocular disparity, which results in increase of the angular size of the moon. The degree of the distortion depends upon the apparent distance to the sky, which is influenced by the surrounding objects and the condition of the sky. The closer the sky appears, the stronger the illusion. At the zenith, few distance cues are present, causing difficulty with distance estimation and weakening the illusion.

  11. Unwanted reflections during slit lamp assisted binocular indirect ophthalmoscopy

    Science.gov (United States)

    Sheehan, Matthew; Goncharov, Alexander

    2011-11-01

    Binocular indirect ophthalmoscopy is a routine ophthalmic examination procedure. Two different apparatus setups are commonly employed; the head/spectacle mounted designs of Schepens and slit lamp assisted ophthalmoscopy, both typically performed through a fundus lens of high positive power. It can be difficult for clinicians to avoid unwanted back reflections primarily emanating from the fundus lens and the pre-corneal tear film, particularly when initially learning the skills required to perform the examination. In this investigation the illumination system of a slit lamp was modified to include a variety of obscuration designs optically conjugate to surfaces responsible for creating unwanted reflections. The modified apparatus was then used to perform binocular indirect ophthalmoscopy on an artificial eye and on real eyes. Clinicians used questionnaires to score the appearance of reflections. The mean scores were similar across all trials, including the control unmodified trial, indicating general consensus that the modified illumination system provided no substantial effect on the perception of these unwanted reflections.

  12. Energy approach to rivalry dynamics, soliton stability, and pattern formation in neuronal networks

    Science.gov (United States)

    Loxley, P. N.; Robinson, P. A.

    2007-10-01

    Hopfield’s Lyapunov function is used to view the stability and topology of equilibria in neuronal networks for visual rivalry and pattern formation. For two neural populations with reciprocal inhibition and slow adaptation, the dynamics of neural activity is found to include a pair of limit cycles: one for oscillations between states where one population has high activity and the other has low activity, as in rivalry, and one for oscillations between states where both populations have the same activity. Hopfield’s Lyapunov function is used to find the dynamical mechanism for oscillations and the basin of attraction of each limit cycle. For a spatially continuous population with lateral inhibition, stable equilibria are found for local regions of high activity (solitons) and for bound states of two or more solitons. Bound states become stable when moving two solitons together minimizes the Lyapunov function, a result of decreasing activity in regions between peaks of high activity when the firing rate is described by a sigmoid function. Lowering the barrier to soliton formation leads to a pattern-forming instability, and a nonlinear solution to the dynamical equations is found to be given by a soliton lattice, which is completely characterized by the soliton width and the spacing between neighboring solitons. Fluctuations due to noise create lattice vacancies analogous to point defects in crystals, leading to activity which is spatially inhomogeneous.

  13. Attachment and sibling rivalry in Little Hans: the fantasy of the two giraffes revisited.

    Science.gov (United States)

    Wakefield, Jerome C

    2007-01-01

    Freud's interpretation of Little Hans's "phantasy of the two giraffes" is pivotal to his oedipal analysis that Hans has inchoate desires for sexual intercourse with his mother. Bowlby argued that Freud's focus on his oedipal theory led him to ignore preoedipal attachment-related factors that have equal plausibility in explaining the clinical data. However, Bowlby did not attempt to apply the attachment perspective to the interpretation of Hans's fantasies that form the core of the case material. A microanalysis of Hans's giraffe fantasy and the evidence used to support Freud's claims about it yields an attachment-based sibling rivalry account arguably of greater explanatory power than the oedipal account. Consistent with Bowlby's hypothesis, the evidence suggests that Hans's giraffe fantasy is about the sibling rivalry triangle involved in caregiver attachment access, rather than (or in addition to) the oedipal triangle. The issue of multiple levels of meaning and the methodological challenges raised by multiple determination is also considered. The giraffe fantasy's attachment-theoretic explanation encourages a rethinking of this classic case and strengthens Bowlby's claim that the case is fruitfully viewed from an attachment perspective.

  14. How Does Binocular Disparity Affect the Impressions in Viewing Stereograms?

    Directory of Open Access Journals (Sweden)

    Makoto Ichikawa

    2012-10-01

    Full Text Available We examined how the size of binocular disparity affects the impressions in different dimensions, as well as apparent depth, in viewing line-contoured stereograms, random dot stereogram, and stereoscopic pictures of naturalistic scenes. We used a semantic differential method with the scales that are related to the different dimensions of impression; evaluation, activity, and potency. The stereograms of naturalistic scenes were selected to give observers strong or weak impressions in different impression dimensions. We prepared the two-depth-layer condition and six-depth-layer condition for those stereograms. The size of binocular disparity between the nearest and farthest layers ranged from 0 to about 70 min of arc. Apparent depth magnitude increased with the increment of disparity size for those stereograms while the increment for the six depth-layer condition was larger than that for the two depth-layer conditions. Regardless of the type of stereograms, for the six depth-layer condition, the rating for the evaluation increased with the size of disparity although, for the two-depth-layer condition, it did not increase at the large disparity size. In addition, the rating for the activity increased with disparity size for both the two depth-layer condition and six depth-layer conditions if the stereogram induced some active impression by itself. These results indicate that the effects of binocular disparity size on apparent depth magnitude and impressions in viewing stereoscopic pictures depend upon the depth structure that is specified by binocular disparity, rather than what the stereogram representationally depicts.

  15. Isolation of Binocular Cues for Motion in Depth

    Directory of Open Access Journals (Sweden)

    Satoshi Shioiri

    2011-05-01

    Full Text Available There are two binocular cues of motion in depth: the interocular velocity difference (IOVD and changing disparity over time (CDOT. Psychophysical evidence for the contribution to perceiving motion in depth has been accumulated for both of the two cues, using techniques to isolate each cue. However, no study estimated seriously how reliably each cue is isolated in the techniques. In this study, we apply a model of motion in depth to estimate how each type of stimuli isolates each of IOVD and CDOT cues. The model consists of the motion energy and the disparity energy detectors as subunits and adds their outputs to built the IOVD and CDOT detectors. Simulations show that some, but not all of stimuli used in the literature are appropriate for isolating cues. The temporally uncorrelated randomdot stereogram isolates CDOT cue and the binocularly uncorrelated randomdot kinematogram isolates IOVD cues. However, temporally anticorreated version of randomdot stereogram has influence of reverse motion components of IOVD and binocularly anticorreated version of randomdot kinematogram has influence of reverse motion components of CDOT. Gratings with opposite orientation between the eyes are also good for isolation of IOVD. We performed psychophysical experiments to examine the plausibility of the model prediction.

  16. Binocular adaptation to near addition lenses in emmetropic adults.

    Science.gov (United States)

    Sreenivasan, Vidhyapriya; Irving, Elizabeth L; Bobier, William R

    2008-05-01

    Near addition lenses are prescribed to pre-presbyopic individuals for treatment of binocular motor problems such as convergence excess and to control the progression of myopia. To date, no investigation has looked at the complete sequence of binocular motor responses during a period of near work with +2D lenses. This investigation evaluated changes to accommodation and vergence responses when young adults sustained fixation at 33 cm with +2D addition lenses. In addition, the effect of the accommodative vergence cross-link (AV/A) on the magnitude and the completeness of binocular adaptation to these lenses were evaluated. The results showed that +2D lenses initiate an increase in exophoria and convergence driven accommodation. The degree of the initial induced phoria was dependant upon the magnitude of the AV/A ratio. Vergence adaptation occurred after 3 min of near fixation and reduced the exophoria and convergence driven accommodation. The magnitude of vergence adaptation was dependant upon the size of the induced phoria and hence the AV/A ratio. The completeness of adaptation was seen to vary inversely with induced exophoria and thus the AV/A ratio.

  17. Binocular interactions underlying the classic optomotor responses of flying flies

    Directory of Open Access Journals (Sweden)

    Brian J Duistermars

    2012-02-01

    Full Text Available In response to imposed course deviations, the fast optomotor reactions of animals reduce motion blur and facilitate the maintenance of stable body posture. In flies, the monocular front-to-back (progressive and back-to-front (regressive visual motion components generated by horizontal rotation are selectively encoded, respectively, by homo and heterolateral motion sensitive circuits in the third optic ganglion, the lobula plate. To investigate the strength of such inter-ocular interactions and their role in compensatory sensory-motor transformations, we utilize a virtual reality flight simulator to record optomotor reactions by tethered flying flies in response to imposed binocular and monocular visual rotation. With stimulus parameters generating large contrast insensitive optomotor responses to binocular rotation, we find that responses to monocular progressive motion are larger than those to panoramic rotation but contrast sensitive. Conversely, responses to monocular regressive motion are slower than those to rotation and peak at the lowest tested contrast. Together our results suggest that contrast insensitive optomotor responses to binocular rotation result from the dynamic interplay of contralateral inhibitory as well as excitatory circuit interactions and serve to maintain a stable optomotor equilibrium across a range of visual contrasts.

  18. [A biotechnical system for diagnosis and treatment of binocular vision impairments].

    Science.gov (United States)

    Korzhuk, N L; Shcheglova, M V

    2008-01-01

    Automation of the binocular vision biorhythm diagnosis and improvement of the efficacy of treatment of vision impairments are important medical problems. In authors' opinion, to solve these problems, it is necessary to take into account the correlation between the binocular vision and the electrical activity of the brain. A biotechnical system for diagnosis and treatment of binocular vision impairments was developed to implement diagnostic and treatment procedures based on the detection of this correlation.

  19. The Effect of Unilateral Mean Luminance on Binocular Combination in normal and amblyopic vision

    OpenAIRE

    Jiawei Zhou; Wuli Jia; Chang-Bing Huang; Hess, Robert F

    2013-01-01

    Luminance plays a modulating role in the processes of several visual tasks, which in turn provides significant information for the understanding of visual processing. Here, using a binocular phase combination paradigm, we studied the effect of unilateral changes in mean luminance on binocular combination in both normal and amblyopic vision. We found, in normal observers, attenuation of one eye's stimulus luminance with neutral density filters produces binocular phase combination similar to th...

  20. Artistic Alliances and Revolutionary Rivalries in the Baltic Art World, 1890-1914

    Directory of Open Access Journals (Sweden)

    Bart Pushaw

    2016-11-01

    Full Text Available In the areas now known as Estonia and Latvia, art remained a matter for the Baltic German minority throughout the nineteenth century. When ethnic Estonian and Latvian artists gained prominence in the late 1890s, their presence threatened Baltic German hegemony over the region’s culture. In 1905, revolution in the Russian Empire spilled into the Baltic Provinces, sparking widespread anti-German violence. The revolution also galvanized Latvian and Estonian artists towards greater cultural autonomy and independence from Baltic German artistic institutions. This paper argues that the situation for artists before and after the 1905 revolution was not simply divisive along ethnic lines, as some nationalist historians have suggested. Instead, this paper examines how Baltic German, Estonian and Latvian artists oscillated between common interests, inspiring rivalries, and politicized conflicts, questioning the legitimacy of art as a universalizing language in multicultural societies.

  1. Recent developments for the Large Binocular Telescope Guiding Control Subsystem

    Science.gov (United States)

    Golota, T.; De La Peña, M. D.; Biddick, C.; Lesser, M.; Leibold, T.; Miller, D.; Meeks, R.; Hahn, T.; Storm, J.; Sargent, T.; Summers, D.; Hill, J.; Kraus, J.; Hooper, S.; Fisher, D.

    2014-07-01

    The Large Binocular Telescope (LBT) has eight Acquisition, Guiding, and wavefront Sensing Units (AGw units). They provide guiding and wavefront sensing capability at eight different locations at both direct and bent Gregorian focal stations. Recent additions of focal stations for PEPSI and MODS instruments doubled the number of focal stations in use including respective motion, camera controller server computers, and software infrastructure communicating with Guiding Control Subsystem (GCS). This paper describes the improvements made to the LBT GCS and explains how these changes have led to better maintainability and contributed to increased reliability. This paper also discusses the current GCS status and reviews potential upgrades to further improve its performance.

  2. Two eyes, one vision: binocular motion perception in human visual cortex

    NARCIS (Netherlands)

    Barendregt, M.

    2016-01-01

    An important aspect of human vision is the fact that it is binocular, i.e. that we have two eyes. As a result, the brain nearly always receives two slightly different images of the same visual scene. Yet, we only perceive a single image and thus our brain has to actively combine the binocular visual

  3. Depth of Monocular Elements in a Binocular Scene: The Conditions for da Vinci Stereopsis

    Science.gov (United States)

    Cook, Michael; Gillam, Barbara

    2004-01-01

    Quantitative depth based on binocular resolution of visibility constraints is demonstrated in a novel stereogram representing an object, visible to 1 eye only, and seen through an aperture or camouflaged against a background. The monocular region in the display is attached to the binocular region, so that the stereogram represents an object which…

  4. Effect of Developmental Binocular Vision Abnormalities on Visual Vertigo Symptoms and Treatment Outcome

    OpenAIRE

    Pavlou, Marousa; Acheson, James; Nicolaou, Despina; Fraser, Clare L.; Bronstein, Adolfo M.; Davies, Rosalyn A.

    2015-01-01

    BACKGROUND AND PURPOSE: Customized vestibular rehabilitation incorporating optokinetic (OK) stimulation improves visual vertigo (VV) symptoms; however, the degree of improvement varies among individuals. Binocular vision abnormalities (misalignment of ocular axis, ie, strabismus) may be a potential risk factor. This study aimed to investigate the influence of binocular vision abnormalities on VV symptoms and treatment outcome.METHODS: Sixty subjects with refractory peripheral vestibular sympt...

  5. Perceptual full-reference quality assessment of stereoscopic images by considering binocular visual characteristics.

    Science.gov (United States)

    Shao, Feng; Lin, Weisi; Gu, Shanbo; Jiang, Gangyi; Srikanthan, Thambipillai

    2013-05-01

    Perceptual quality assessment is a challenging issue in 3D signal processing research. It is important to study 3D signal directly instead of studying simple extension of the 2D metrics directly to the 3D case as in some previous studies. In this paper, we propose a new perceptual full-reference quality assessment metric of stereoscopic images by considering the binocular visual characteristics. The major technical contribution of this paper is that the binocular perception and combination properties are considered in quality assessment. To be more specific, we first perform left-right consistency checks and compare matching error between the corresponding pixels in binocular disparity calculation, and classify the stereoscopic images into non-corresponding, binocular fusion, and binocular suppression regions. Also, local phase and local amplitude maps are extracted from the original and distorted stereoscopic images as features in quality assessment. Then, each region is evaluated independently by considering its binocular perception property, and all evaluation results are integrated into an overall score. Besides, a binocular just noticeable difference model is used to reflect the visual sensitivity for the binocular fusion and suppression regions. Experimental results show that compared with the relevant existing metrics, the proposed metric can achieve higher consistency with subjective assessment of stereoscopic images.

  6. Paucity of horizontal connections for binocular vision in V1 of naturally strabismic macaques: Cytochrome oxidase compartment specificity.

    Science.gov (United States)

    Tychsen, Lawrence; Wong, Agnes Ming-Fong; Burkhalter, Andreas

    2004-06-21

    To describe the structural basis for lack of binocular fusion in strabismic primates, we investigated intrinsic horizontal connections within striate cortex (area V1) of normal and strabismic, adult macaque monkeys. The strabismic animals had early-onset natural esotropia (the visual axes deviated nasally), normal visual acuity in each eye, and the constellation of ocular motor deficits that typify human infantile strabismus. Horizontal patchy connections and synaptic boutons were labeled by injections of the neuronal tracer biotinylated dextran amine. Ocular dominance columns (ODCs), and blob vs. interblob compartments, were revealed by using cytochrome oxidase (CO). In layers 2/3 and 4B of the strabismic monkeys, patchy projections and boutons terminated much more frequently in same-eye (73%) as opposed to opposite-eye (27%) ODCs (normal monkeys 58% and 42%, respectively). The deficiency of binocular connections in the strabismic cortex was evident qualitatively as a "skip" pattern, in which every other row of ODCs had labeled patches. Analysis of V1 in normal monkeys revealed that the deficits in strabismic V1 were due mainly to a loss of binocular connections between neurons in CO-interblob compartments. In both normal and strabismic monkeys: (1) CO-blob compartment neurons showed a more pronounced bias for monocular connectivity, and (2) commitment of connections to the same CO-compartment as the injection site (blob-to-blob, or interblob-to-interblob) was moderately strong (64%) but far from absolute. These findings help elucidate the relative roles of visual experience vs. innate mechanisms in the development of axonal connections between ocular dominance domains and compartments within macaque V1. They also provide the first detailed description of the V1 maldevelopments associated with unrepaired natural, infantile-onset strabismus in primates.

  7. Evaluation of Binocular Vision Therapy Efficacy by 3D Video-Oculography Measurement of Binocular Alignment and Motility

    OpenAIRE

    Laria Ochaíta, Carlos; Piñero Llorens, David Pablo

    2013-01-01

    Objective: To evaluate two cases of intermittent exotropia (IX(T)) treated by vision therapy the efficacy of the treatment by complementing the clinical examination with a 3-D video-oculography to register and to evidence the potential applicability of this technology for such purpose. Methods: We report the binocular alignment changes occurring after vision therapy in a woman of 36 years with an IX(T) of 25 prism diopters (Δ) at far and 18 Δ at near and a child of 10 years with 8 Δ of IX(T) ...

  8. An improved measurement model of binocular vision using geometrical approximation

    Science.gov (United States)

    Wang, Qiyue; Wang, Zhongyu; Yao, Zhenjian; Forrest, Jeffrey; Zhou, Weihu

    2016-12-01

    In order to improve the precision of a binocular vision measurement system, an effective binocular vision measurement method, named geometrical approximation, is proposed. This method can optimize the measurement results by geometrical approximation operation based on the principles of optimization theory and spatial geometry. To evaluate the properties of the proposed method, both simulative and practical experiments are carried out. The influence of image noise and focal length error on measurement results is discussed. The results show that measurement performance of the proposed method is manifested well. Besides, the proposed method is also compared with Bundle adjustment and least squares method in a practical experiment. The experiment results indicate that the average error, calculated by using the proposed method, is 0.076 mm less than Bundle adjustment’s 0.085 mm, and only half of the least squares method’s 0.146 mm. At the meantime, the proposed method enjoys a high level of computational efficiency when compared to Bundle adjustment. Since no nonlinear iteration optimization is involved, this method can be applied readily to real time on-line measurements.

  9. An augmented reality binocular system (ARBS) for air traffic controllers

    Science.gov (United States)

    Fulbrook, Jim E.; Ruffner, John W.; Labbe, Roger

    2008-04-01

    The primary means by which air traffic tower controllers obtain information is through direct out-thewindow viewing, although a considerable amount of time is spent looking at electronic displays and other information sources inside the tower cab. The Air Force Research Laboratory sponsored the development of a prototype Augmented Reality Binocular System (ARBS) that enhances tower controller performance, situation awareness, and safety. The ARBS is composed of a virtual binocular (VB) that displays real-time imagery from high resolution telephoto cameras and sensors mounted on pan/tilt units (PTUs). The selected PTU tracks to the movement of the VB, which has an inertial heading and elevation sensor. Relevant airfield situation text and graphic depictions that identify airfield features are overlaid on the imagery. In addition, the display is capable of labeling and tracking vehicles on which an Automatic Dependent Surveillance - Broadcast (ADS-B) system has been installed. The ARBS provides air traffic controllers and airfield security forces with the capability to orient toward, observe, and conduct continuous airfield operations and surveillance/security missions from any number of viewing aspects in limited visibility conditions. In this paper, we describe the ARBS in detail, discuss the results of a Usability Test of the prototype ARBS, and discuss ideas for follow-on efforts to develop the ARBS to a fieldable level.

  10. Moving toward queue operations at the Large Binocular Telescope Observatory

    Science.gov (United States)

    Edwards, Michelle L.; Summers, Doug; Astier, Joseph; Suarez Sola, Igor; Veillet, Christian; Power, Jennifer; Cardwell, Andrew; Walsh, Shane

    2016-07-01

    The Large Binocular Telescope Observatory (LBTO), a joint scientific venture between the Instituto Nazionale di Astrofisica (INAF), LBT Beteiligungsgesellschaft (LBTB), University of Arizona, Ohio State University (OSU), and the Research Corporation, is one of the newest additions to the world's collection of large optical/infrared ground-based telescopes. With its unique, twin 8.4m mirror design providing a 22.8 meter interferometric baseline and the collecting area of an 11.8m telescope, LBT has a window of opportunity to exploit its singular status as the "first" of the next generation of Extremely Large Telescopes (ELTs). Prompted by urgency to maximize scientific output during this favorable interval, LBTO recently re-evaluated its operations model and developed a new strategy that augments classical observing with queue. Aided by trained observatory staff, queue mode will allow for flexible, multi-instrument observing responsive to site conditions. Our plan is to implement a staged rollout that will provide many of the benefits of queue observing sooner rather than later - with more bells and whistles coming in future stages. In this paper, we outline LBTO's new scientific model, focusing specifically on our "lean" resourcing and development, reuse and adaptation of existing software, challenges presented from our one-of-a-kind binocular operations, and lessons learned. We also outline further stages of development and our ultimate goals for queue.

  11. The tragedy of the commons, the public goods dilemma, and the meaning of rivalry and excludability in evolutionary biology

    OpenAIRE

    Dionisio, F; Gordo, I.

    2006-01-01

    Problem: In the study of conflicts, both economists and evolutionary biologists use the concepts ‘tragedy of the commons’ and ‘public goods dilemma’. What is the relationship between the economist and evolutionist views of these concepts? Model features: The economics literature defines the tragedy of the commons and the public goods dilemma in terms of rivalry and excludability of the good. In contrast, evolutionists define these conflicts based on fitness functions with two c...

  12. Bilateral symmetry in vision and influence of ocular surgical procedures on binocular vision: A topical review.

    Science.gov (United States)

    Arba Mosquera, Samuel; Verma, Shwetabh

    2016-01-01

    We analyze the role of bilateral symmetry in enhancing binocular visual ability in human eyes, and further explore how efficiently bilateral symmetry is preserved in different ocular surgical procedures. The inclusion criterion for this review was strict relevance to the clinical questions under research. Enantiomorphism has been reported in lower order aberrations, higher order aberrations and cone directionality. When contrast differs in the two eyes, binocular acuity is better than monocular acuity of the eye that receives higher contrast. Anisometropia has an uncommon occurrence in large populations. Anisometropia seen in infancy and childhood is transitory and of little consequence for the visual acuity. Binocular summation of contrast signals declines with age, independent of inter-ocular differences. The symmetric associations between the right and left eye could be explained by the symmetry in pupil offset and visual axis which is always nasal in both eyes. Binocular summation mitigates poor visual performance under low luminance conditions and strong inter-ocular disparity detrimentally affects binocular summation. Considerable symmetry of response exists in fellow eyes of patients undergoing myopic PRK and LASIK, however the method to determine whether or not symmetry is maintained consist of comparing individual terms in a variety of ad hoc ways both before and after the refractive surgery, ignoring the fact that retinal image quality for any individual is based on the sum of all terms. The analysis of bilateral symmetry should be related to the patients' binocular vision status. The role of aberrations in monocular and binocular vision needs further investigation.

  13. Binocular function in unilateral aphakia. Correlation with aniseikonia and stereoacuity.

    Science.gov (United States)

    Katsumi, O; Miyanaga, Y; Hirose, T; Okuno, H; Asaoka, I

    1988-08-01

    Aniseikonia and stereoacuity were measured in patients with unilateral aphakia, most of whom were postoperative senile cataract cases. The New Aniseikonia test was used to evaluate aniseikonia and the Titmus Stereotest to measure stereoacuity. Ninety cases were studied, 57 (63.3%) of which had intraocular lens (IOL) implants; 27 (30%) had extended-wear soft contact lenses; and six (6.7%) had spectacle lenses. In the IOL group, aniseikonia averaged 2.8%, and 39 patients (68.4%) had good stereoacuity. In the contact lens group, aniseikonia averaged 4.6%, and 11 (40.7%) had good stereoacuity. In the spectacle lens group, aniseikonia averaged 17.8%; none of the patients had good stereoacuity. The authors concluded that in cases with unilateral aphakia, correction with an IOL implant is superior to the other alternatives in achieving good binocular function.

  14. Origins of strabismus and loss of binocular vision

    Directory of Open Access Journals (Sweden)

    Emmanuel eBui Quoc

    2014-09-01

    Full Text Available Strabismus is a frequent ocular disorder that develops early in life in humans. As a general rule, it is characterized by a misalignment of the visual axes which most often appears during the critical period of visual development. However other characteristics of strabismus may vary greatly among subjects, for example, being convergent or divergent, horizontal or vertical, with variable angles of deviation. Binocular vision may also vary greatly. Our main goal here is to develop the idea that such polymorphy reflects a wide variety in the possible origins of strabismus. We propose that strabismus must be considered as possibly resulting from abnormal genetic and/or acquired factors, anatomical and/or functional abnormalities, in the sensory and/or the motor systems, both peripherally and/or in the brain itself. We shall particularly develop the possible central origins of strabismus. Indeed, we are convinced that it is time now to open this black box in order to move forward. All of this will be developed on the basis of both presently available data in literature (including most recent data and our own experience. Both data in medicine and biology will be referred to. Our conclusions will hopefully help ophthalmologists to better understand strabismus and to develop new therapeutic strategies in the future. Presently, physicians eliminate or limit the negative effects of such pathology both on the development of the visual system and visual perception through the use of optical correction and, in some cases, extraocular muscle surgery. To better circumscribe the problem of the origins of strabismus, including at a cerebral level, may improve its management, in particular with respect to binocular vision, through innovating tools by treating the pathology at the source.

  15. Robust Active Binocular Vision through Intrinsically Motivated Learning

    Directory of Open Access Journals (Sweden)

    Luca eLonini

    2013-11-01

    Full Text Available The efficient coding hypothesis posits that sensory systems of animals strive to encode sensory signals efficiently by taking into account the redundancies in them. This principle has been very successful in explaining response properties of visual sensory neurons as adaptations to the statistics of natural images. Recently, we have begun to extend the efficient coding hypothesis to active perception through a form of intrinsically motivated learning: a sensory model learns an efficient code for the sensory signals while a reinforcement learner generates movements of the sense organs to improve the encoding of the signals. To this end, it receives an intrinsically generated reinforcement signal indicating how well the sensory model encodes the data. This approach has been tested in the context of binocular vison, leading to the autonomous development of disparity tuning and vergence control. Here we systematically investigate the robustness of the new approach in the context of a binocular vision system implemented on a robot. Robustness is an important aspect that reflects the ability of the system to deal with unmodeled disturbances or events, such as an insult to the system that displace the stereo cameras. To demonstrate the robustness of our method and its ability to self-calibrate, we introduce various perturbations and test if and how the system recovers from them. We find that 1 the system can fully recover from a perturbation that can be compensated through the system's motor degrees of freedom, 2 performance degrades gracefully if the system cannot use its motor degrees of freedom to compensate for the perturbation, and 3 recovery from a perturbation is improved if both the sensory encoding and the behavior policy can adapt to the perturbation. Overall, this work demonstrates that our intrinsically motivated learning approach for efficient coding in active perception gives rise to a self-calibrating perceptual system of high robustness.

  16. Robust active binocular vision through intrinsically motivated learning.

    Science.gov (United States)

    Lonini, Luca; Forestier, Sébastien; Teulière, Céline; Zhao, Yu; Shi, Bertram E; Triesch, Jochen

    2013-01-01

    The efficient coding hypothesis posits that sensory systems of animals strive to encode sensory signals efficiently by taking into account the redundancies in them. This principle has been very successful in explaining response properties of visual sensory neurons as adaptations to the statistics of natural images. Recently, we have begun to extend the efficient coding hypothesis to active perception through a form of intrinsically motivated learning: a sensory model learns an efficient code for the sensory signals while a reinforcement learner generates movements of the sense organs to improve the encoding of the signals. To this end, it receives an intrinsically generated reinforcement signal indicating how well the sensory model encodes the data. This approach has been tested in the context of binocular vison, leading to the autonomous development of disparity tuning and vergence control. Here we systematically investigate the robustness of the new approach in the context of a binocular vision system implemented on a robot. Robustness is an important aspect that reflects the ability of the system to deal with unmodeled disturbances or events, such as insults to the system that displace the stereo cameras. To demonstrate the robustness of our method and its ability to self-calibrate, we introduce various perturbations and test if and how the system recovers from them. We find that (1) the system can fully recover from a perturbation that can be compensated through the system's motor degrees of freedom, (2) performance degrades gracefully if the system cannot use its motor degrees of freedom to compensate for the perturbation, and (3) recovery from a perturbation is improved if both the sensory encoding and the behavior policy can adapt to the perturbation. Overall, this work demonstrates that our intrinsically motivated learning approach for efficient coding in active perception gives rise to a self-calibrating perceptual system of high robustness.

  17. Two-eyed versus one-eyed salamanders: does binocularity enhance the optically evoked skin blanching reactions of Ambystoma larvae?

    Science.gov (United States)

    Pietsch, P; Schneider, C W

    1990-08-01

    A wide variety of visual functions show increases attributable to binocularity, and the question pursued here was whether a second eye enhances the visually stimulated skin blanching reaction of the larval salamander. Dermal melanin spots (produced by the aggregations of melanosomes within dermal melanophores and which contract or expand to lighten or darken the skin) were measured in eyeless (controls), one-eyed and two-eyed Ambystoma punctatum larvae after chronic adaptation of the subjects to a white background (i.e., stimulus conditions for maximum blanching). The eyeless subjects showed no blanching (thus remained dark) in white cups, and they exhibited melanin spots 7 or 8 times the size of those of the other two groups. All one-eyed or two-eyed subjects exhibited blanching reactions; planometric comparison revealed a significantly larger melanin spot area for one-eyed than for two-eyed animals; i.e., the binocular condition permitted greater contraction of the pigment spots than did the monocular condition. Analytical data compared favorably with independently ascertained pigmentation indices. The results indicate that a second eye quantitatively elevates the blanching maximum of a larval salamander.

  18. Reaction time as a measure of binocular interaction in human vision.

    Science.gov (United States)

    Blake, R; Martens, W; Di Gianfilippo, A

    1980-08-01

    In a series of psychophysical experiments monocular and binocular reaction times (RTs) were measured in response to the presentation of sinusoidal grating patterns. Over a wide range of contrast values, binocular RT was consistently faster than monocular RT, even at high-contrast levels where RT had reached asymptotic levels. For observers with good stereopsis this binocular summation effect was greater than that expected on the basis of probability summation alone, whereas observers with deficient stereopsis performed at the level of probability summation. For normal observers broadband random noise presented to one eye produced an elevation in RT to gratings presented to the other eye; no such dichoptic masking effect was found in a stereoblind observer. These results validate the use of RT as an efficient, reliable measure of binocular interaction in human vision.

  19. Problems with balance and binocular visual dysfunction are associated with post-stroke fatigue

    DEFF Research Database (Denmark)

    Schow, Trine; Teasdale, Thomas William; Jensen Quas, Kirsten;

    2016-01-01

    Trine Schow, Thomas William Teasdale, Kirsten Jensen Quas& Morten Arendt Rasmussen (2016): Problems with balance and binocular visual dysfunction are associated with post-stroke fatigue, Topics in Stroke Rehabilitation, DOI: 10.1080/10749357.2016.1188475......Trine Schow, Thomas William Teasdale, Kirsten Jensen Quas& Morten Arendt Rasmussen (2016): Problems with balance and binocular visual dysfunction are associated with post-stroke fatigue, Topics in Stroke Rehabilitation, DOI: 10.1080/10749357.2016.1188475...

  20. Amount of aniseikonia compatible with fine binocular vision: some old and new concepts.

    Science.gov (United States)

    Campos, E C; Enoch, J M

    1980-01-01

    Random Dot Stereograms (RDS) are useful, but are sometimes misleading in assessing the degree of binocular cooperation in the presence of aniseikonia. RDS may give positive results up to 15% aniseikonia, whereas a fine central binocularity is not possible with more than 5% image-size difference. It is suggested that stereopsis may not be the only parameter to test; stress is given to the importance of peripheral motor fusion in maintaining the eye alignment.

  1. Differential processing of binocular and monocular gloss cues in human visual cortex

    Science.gov (United States)

    Di Luca, Massimiliano; Ban, Hiroshi; Muryy, Alexander; Fleming, Roland W.

    2016-01-01

    The visual impression of an object's surface reflectance (“gloss”) relies on a range of visual cues, both monocular and binocular. Whereas previous imaging work has identified processing within ventral visual areas as important for monocular cues, little is known about cortical areas involved in processing binocular cues. Here, we used human functional MRI (fMRI) to test for brain areas selectively involved in the processing of binocular cues. We manipulated stereoscopic information to create four conditions that differed in their disparity structure and in the impression of surface gloss that they evoked. We performed multivoxel pattern analysis to find areas whose fMRI responses allow classes of stimuli to be distinguished based on their depth structure vs. material appearance. We show that higher dorsal areas play a role in processing binocular gloss information, in addition to known ventral areas involved in material processing, with ventral area lateral occipital responding to both object shape and surface material properties. Moreover, we tested for similarities between the representation of gloss from binocular cues and monocular cues. Specifically, we tested for transfer in the decoding performance of an algorithm trained on glossy vs. matte objects defined by either binocular or by monocular cues. We found transfer effects from monocular to binocular cues in dorsal visual area V3B/kinetic occipital (KO), suggesting a shared representation of the two cues in this area. These results indicate the involvement of mid- to high-level visual circuitry in the estimation of surface material properties, with V3B/KO potentially playing a role in integrating monocular and binocular cues. PMID:26912596

  2. M pathway and areas 44 and 45 are involved in stereoscopic recognition based on binocular disparity.

    Science.gov (United States)

    Negawa, Tsuneo; Mizuno, Shinji; Hahashi, Tomoya; Kuwata, Hiromi; Tomida, Mihoko; Hoshi, Hiroaki; Era, Seiichi; Kuwata, Kazuo

    2002-04-01

    We characterized the visual pathways involved in the stereoscopic recognition of the random dot stereogram based on the binocular disparity employing a functional magnetic resonance imaging (fMRI). The V2, V3, V4, V5, intraparietal sulcus (IPS) and the superior temporal sulcus (STS) were significantly activated during the binocular stereopsis, but the inferotemporal gyrus (ITG) was not activated. Thus a human M pathway may be part of a network involved in the stereoscopic processing based on the binocular disparity. It is intriguing that areas 44 (Broca's area) and 45 in the left hemisphere were also active during the binocular stereopsis. However, it was reported that these regions were inactive during the monocular stereopsis. To separate the specific responses directly caused by the stereoscopic recognition process from the nonspecific ones caused by the memory load or the intention, we designed a novel frequency labeled tasks (FLT) sequence. The functional MRI using the FLT indicated that the activation of areas 44 and 45 is correlated with the stereoscopic recognition based on the binocular disparity but not with the intention artifacts, suggesting that areas 44 and 45 play an essential role in the binocular disparity.

  3. Smooth pursuit detection in binocular eye-tracking data with automatic video-based performance evaluation.

    Science.gov (United States)

    Larsson, Linnéa; Nyström, Marcus; Ardö, Håkan; Åström, Kalle; Stridh, Martin

    2016-12-01

    An increasing number of researchers record binocular eye-tracking signals from participants viewing moving stimuli, but the majority of event-detection algorithms are monocular and do not consider smooth pursuit movements. The purposes of the present study are to develop an algorithm that discriminates between fixations and smooth pursuit movements in binocular eye-tracking signals and to evaluate its performance using an automated video-based strategy. The proposed algorithm uses a clustering approach that takes both spatial and temporal aspects of the binocular eye-tracking signal into account, and is evaluated using a novel video-based evaluation strategy based on automatically detected moving objects in the video stimuli. The binocular algorithm detects 98% of fixations in image stimuli compared to 95% when only one eye is used, while for video stimuli, both the binocular and monocular algorithms detect around 40% of smooth pursuit movements. The present article shows that using binocular information for discrimination of fixations and smooth pursuit movements is advantageous in static stimuli, without impairing the algorithm's ability to detect smooth pursuit movements in video and moving-dot stimuli. With an automated evaluation strategy, time-consuming manual annotations are avoided and a larger amount of data can be used in the evaluation process.

  4. An overview of instrumentation for the Large Binocular Telescope

    Science.gov (United States)

    Wagner, R. Mark

    2012-09-01

    An overview of instrumentation for the Large Binocular Telescope (LBT) is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (27' x 27') mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the left and right direct F/15 Gregorian foci incorporating multiple slit masks for multi-object spectroscopy over a 6' field and spectral resolutions of up to 2000. Infrared instrumentation includes the LBT Near-IR Spectroscopic Utility with Camera and Integral Field Unit for Extragalactic Research (LUCI), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at the left and right front bent F/15 Gregorian foci and designed for seeing-limited (FOV: 4' × 4') imaging, long-slit spectroscopy, and multiobject spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0'.5 × 0'.5) imaging and long-slit spectroscopy. Strategic instruments under development that can utilize the full 23-m baseline of the LBT include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near-infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). LBTI is currently undergoing commissioning on the LBT and utilizing the installed adaptive secondary mirrors in both single- sided and two-sided beam combination modes. In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. Over the past four years the LBC pair, LUCI1, and MODS1 have been commissioned and are now scheduled for routine partner science observations. The delivery of both LUCI2 and MODS2 is anticipated before the end of 2012. The

  5. Binocular stereo vision system based on phase matching

    Science.gov (United States)

    Liu, Huixian; Huang, Shujun; Gao, Nan; Zhang, Zonghua

    2016-11-01

    Binocular stereo vision is an efficient way for three dimensional (3D) profile measurement and has broad applications. Image acquisition, camera calibration, stereo matching, and 3D reconstruction are four main steps. Among them, stereo matching is the most important step that has a significant impact on the final result. In this paper, a new stereo matching technique is proposed to combine the absolute fringe order and the unwrapped phase of every pixel. Different from traditional phase matching method, sinusoidal fringe in two perpendicular directions are projected. It can be realized through the following three steps. Firstly, colored sinusoidal fringe in both horizontal (red fringe) and vertical (blue fringe) are projected on the object to be measured, and captured by two cameras synchronously. The absolute fringe order and the unwrapped phase of each pixel along the two directions are calculated based on the optimum three-fringe numbers selection method. Then, based on the absolute fringe order of the left and right phase maps, stereo matching method is presented. In this process, the same absolute fringe orders in both horizontal and vertical directions are searched to find the corresponding point. Based on this technique, as many as possible pairs of homologous points between two cameras are found to improve the precision of the measurement result. Finally, a 3D measuring system is set up and the 3D reconstruction results are shown. The experimental results show that the proposed method can meet the requirements of high precision for industrial measurements.

  6. Pediatric vision screening using binocular retinal birefringencr scanning

    Science.gov (United States)

    Nassif, Deborah S.; Gramatikov, Boris; Guyton, David L.; Hunter, David G.

    2003-07-01

    Amblyopia, a leading cause of vision loss in childhood, is responsive to treatment if detected early in life. Risk factors for amblyopia, such as refractive error and strabismus, may be difficult to identify clinically in young children. Our laboratory has developed retinal birefringence scanning (RBS), in which a small spot of polarized light is scanned in a circle on the retina, and the returning light is measured for changes in polarization caused by the pattern of birefringent fibers that comprise the fovea. Binocular RBS (BRBS) detects the fixation of both eyes simultaneously and thus screens for strabismus, one of the risk factors of amblyopia. We have also developed a technique to automatically detect when the eye is in focus without measuring refractive error. This focus detection system utilizes a bull's eye photodetector optically conjugate to a point fixation source. Reflected light is focused back to the point source by the optical system of the eye, and if the subject focuses on the fixation source, the returning light will be focused on the detector. We have constructed a hand-held prototype combining BRBS and focus detection measurements in one quick (< 0.5 second) and accurate (theoretically detecting +/-1 of misalignment) measurement. This approach has the potential to reliably identify children at risk for amblyopia.

  7. Temporal Integration of Auditory Stimulation and Binocular Disparity Signals

    Directory of Open Access Journals (Sweden)

    Marina Zannoli

    2011-10-01

    Full Text Available Several studies using visual objects defined by luminance have reported that the auditory event must be presented 30 to 40 ms after the visual stimulus to perceive audiovisual synchrony. In the present study, we used visual objects defined only by their binocular disparity. We measured the optimal latency between visual and auditory stimuli for the perception of synchrony using a method introduced by Moutoussis & Zeki (1997. Visual stimuli were defined either by luminance and disparity or by disparity only. They moved either back and forth between 6 and 12 arcmin or from left to right at a constant disparity of 9 arcmin. This visual modulation was presented together with an amplitude-modulated 500 Hz tone. Both modulations were sinusoidal (frequency: 0.7 Hz. We found no difference between 2D and 3D motion for luminance stimuli: a 40 ms auditory lag was necessary for perceived synchrony. Surprisingly, even though stereopsis is often thought to be slow, we found a similar optimal latency in the disparity 3D motion condition (55 ms. However, when participants had to judge simultaneity for disparity 2D motion stimuli, it led to larger latencies (170 ms, suggesting that stereo motion detectors are poorly suited to track 2D motion.

  8. EXO-ZODI MODELING FOR THE LARGE BINOCULAR TELESCOPE INTERFEROMETER

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Grant M.; Wyatt, Mark C.; Panić, Olja; Shannon, Andrew [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Bailey, Vanessa; Defrère, Denis; Hinz, Philip M.; Rieke, George H.; Skemer, Andrew J.; Su, Katherine Y. L. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bryden, Geoffrey; Mennesson, Bertrand; Morales, Farisa; Serabyn, Eugene [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Danchi, William C.; Roberge, Aki; Stapelfeldt, Karl R. [NASA Goddard Space Flight Center, Exoplanets and Stellar Astrophysics, Code 667, Greenbelt, MD 20771 (United States); Haniff, Chris [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Lebreton, Jérémy [Infrared Processing and Analysis Center, MS 100-22, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); Millan-Gabet, Rafael [NASA Exoplanet Science Institute, California Institute of Technology, 770 South Wilson Avenue, Pasadena, CA 91125 (United States); and others

    2015-02-01

    Habitable zone dust levels are a key unknown that must be understood to ensure the success of future space missions to image Earth analogs around nearby stars. Current detection limits are several orders of magnitude above the level of the solar system's zodiacal cloud, so characterization of the brightness distribution of exo-zodi down to much fainter levels is needed. To this end, the Large Binocular Telescope Interferometer (LBTI) will detect thermal emission from habitable zone exo-zodi a few times brighter than solar system levels. Here we present a modeling framework for interpreting LBTI observations, which yields dust levels from detections and upper limits that are then converted into predictions and upper limits for the scattered light surface brightness. We apply this model to the HOSTS survey sample of nearby stars; assuming a null depth uncertainty of 10{sup –4} the LBTI will be sensitive to dust a few times above the solar system level around Sun-like stars, and to even lower dust levels for more massive stars.

  9. A buyer's and user's guide to astronomical telescopes and binoculars

    CERN Document Server

    Mullaney, James

    2014-01-01

    Amateur astronomers of all skill levels are always contemplating their next telescope, and this book points the way to the most suitable instruments. Similarly, those who are buying their first telescopes – and these days not necessarily a low-cost one – will be able to compare and contrast different types and manufacturers. This revised new guide provides an extensive overview of binoculars and telescopes. It includes detailed up-to-date information on sources, selection and use of virtually every major type, brand, and model on today’s market, a truly invaluable treasure-trove of information and helpful advice for all amateur astronomers. Originally written in 2006, much of the first edition is inevitably now out of date, as equipment advances and manufacturers come and go. This second edition not only updates all the existing sections but adds two new ones: Astro-imaging and Professional-Amateur collaboration. Thanks to the rapid and amazing developments that have been made in digital cameras it is...

  10. Binocular eye tracking with the Tracking Scanning Laser Ophthalmoscope.

    Science.gov (United States)

    Stevenson, S B; Sheehy, C K; Roorda, A

    2016-01-01

    The development of high magnification retinal imaging has brought with it the ability to track eye motion with a precision of less than an arc minute. Previously these systems have provided only monocular records. Here we describe a modification to the Tracking Scanning Laser Ophthalmoscope (Sheehy et al., 2012) that splits the optical path in a way that slows the left and right retinas to be scanned almost simultaneously by a single system. A mirror placed at a retinal conjugate point redirects half of each horizontal scan line to the fellow eye. The collected video is a split image with left and right retinas appearing side by side in each frame. Analysis of the retinal motion in the recorded video provides an eye movement trace with very high temporal and spatial resolution. Results are presented from scans of subjects with normal ocular motility that fixated steadily on a green laser dot. The retinas were scanned at 4° eccentricity with a 2° square field. Eye position was extracted offline from recorded videos with an FFT based image analysis program written in Matlab. The noise level of the tracking was estimated to range from 0.25 to 0.5arcmin SD for three subjects. In the binocular recordings, the left eye/right eye difference was 1-2arcmin SD for vertical motion and 10-15arcmin SD for horizontal motion, in agreement with published values from other tracking techniques.

  11. Early laser operations at the Large Binocular Telescope Observatory

    Science.gov (United States)

    Rahmer, Gustavo; Lefebvre, Michael; Christou, Julian; Raab, Walfried; Rabien, Sebastian; Ziegleder, Julian; Borelli, José L.; Gässler, Wolfgang

    2014-08-01

    ARGOS is the GLAO (Ground-Layer Adaptive Optics) Rayleigh-based LGS (Laser Guide Star) facility for the Large Binocular Telescope Observatory (LBTO). It is dedicated for observations with LUCI1 and LUCI2, LBTO's pair of NIR imagers and multi-object spectrographs. The system projects three laser beams from the back of each of the two secondary mirror units, which create two constellations circumscribed on circles of 2 arcmin radius with 120 degree spacing. Each of the six Nd:YAG lasers provides a beam of green (532nm) pulses at a rate of 10kHz with a power of 14W to 18W. We achieved first on-sky propagation on the night of November 5, 2013, and commissioning of the full system will take place during 2014. We present the initial results of laser operations at the observatory, including safety procedures and the required coordination with external agencies (FAA, Space Command, and Military Airspace Manager). We also describe our operational procedures and report on our experiences with aircraft spotters. Future plans for safer and more efficient aircraft monitoring and detection are discussed.

  12. Binocular adaptive optics visual simulator: understanding the impact of aberrations on actual vision

    Science.gov (United States)

    Fernández, Enrique J.; Prieto, Pedro M.; Artal, Pablo

    2010-02-01

    A novel adaptive optics system is presented for the study of vision. The apparatus is capable for binocular operation. The binocular adaptive optics visual simulator permits measuring and manipulating ocular aberrations of the two eyes simultaneously. Aberrations can be corrected, or modified, while the subject performs visual testing under binocular vision. One of the most remarkable features of the apparatus consists on the use of a single correcting device, and a single wavefront sensor (Hartmann-Shack). Both the operation and the total cost of the instrument largely benefit from this attribute. The correcting device is a liquid-crystal-on-silicon (LCOS) spatial light modulator. The basic performance of the visual simulator consists in the simultaneous projection of the two eyes' pupils onto both the corrector and sensor. Examples of the potential of the apparatus for the study of the impact of the aberrations under binocular vision are presented. Measurements of contrast sensitivity with modified combinations of spherical aberration through focus are shown. Special attention was paid on the simulation of monovision, where one eye is corrected for far vision while the other is focused at near distance. The results suggest complex binocular interactions. The apparatus can be dedicated to the better understanding of the vision mechanism, which might have an important impact in developing new protocols and treatments for presbyopia. The technique and the instrument might contribute to search optimized ophthalmic corrections.

  13. Loss of binocular vision as direct cause for misrouting of temporal retinal fibers in albinism.

    Science.gov (United States)

    Banihani, Saleh M

    2015-10-01

    In humans, the nasal retina projects to the contralateral hemisphere, whereas the temporal retina projects ipsilaterally. The nasotemporal line that divides the retina into crossed and uncrossed parts coincides with the vertical meridian through the fovea. This normal projection of the retina is severely altered in albinism, in which the nasotemporal line shifted into the temporal retina with temporal retinal fibers cross the midline at the optic chiasm. This study proposes the loss of binocular vision as direct cause for misrouting of temporal retinal fibers and shifting of the nasotemporal line temporally in albinism. It is supported by many observations that clearly indicate that loss of binocular vision causes uncrossed retinal fibers to cross the midline. This hypothesis may alert scientists and clinicians to find ways to prevent or minimize the loss of binocular vision that may occur in some diseases such as albinism and early squint. Hopefully, this will minimize the misrouting of temporal fibers and improve vision in such diseases.

  14. Binocular Visual Navigation and Obstacle Avoidance of Mobile Robots Based on Speeded-Up Robust Features

    Institute of Scientific and Technical Information of China (English)

    WANG Meng-di; HAN Bao-ling; LUO Qing-sheng

    2013-01-01

    This article presents a good robust and real-time system scheme of the mobile robot obstacle detection and navigation, which principle of work is based on the feature descriptor SURF. In this scheme, firstly, the image information of the mobile robot path was captured by the binocular camera; then the feature points were extracted and corresponding matched using SURF to the binocular images as the undetected obstacles;finally fixed the position of the objective by the parallax between the matching points combining with the binocular vision calibration model. Theoretical derivation and experimental results show that this scheme is more accurate for the detection and navigation of the interest points. It has fast matching speed and high accuracy and low error. So, it has certain practical effect and popularizing value for the mobile robot real-time obstacle avoidance and navigation.

  15. An assembly system based on industrial robot with binocular stereo vision

    Science.gov (United States)

    Tang, Hong; Xiao, Nanfeng

    2017-01-01

    This paper proposes an electronic part and component assembly system based on an industrial robot with binocular stereo vision. Firstly, binocular stereo vision with a visual attention mechanism model is used to get quickly the image regions which contain the electronic parts and components. Secondly, a deep neural network is adopted to recognize the features of the electronic parts and components. Thirdly, in order to control the end-effector of the industrial robot to grasp the electronic parts and components, a genetic algorithm (GA) is proposed to compute the transition matrix and the inverse kinematics of the industrial robot (end-effector), which plays a key role in bridging the binocular stereo vision and the industrial robot. Finally, the proposed assembly system is tested in LED component assembly experiments, and the results denote that it has high efficiency and good applicability.

  16. [Pay attention to recovery of the binocular vision following strabismus surgery].

    Science.gov (United States)

    Niu, Lan-jun

    2005-07-01

    The primary goal of strabismus treatment is to correct and reverse a pathologic condition. Successful treatment is associated with relief from visual confusion or diplopia, a very high incidence of sensory binocular vision, an expanded peripheral visual field, and improved psychosocial function. Binocularity before and after strabismus surgery should be well understood. The stereopsis or sensory fusion should be examined routinely. The measurements should be repeated with the angle of strabismus neutralized with loose prisms. Eye misalignment is measured using the alternate prism and cover test, Eye alignment is measured using the simultaneous prism and cover test. The recent find is that the maximum horizontal deviation that will support true stereopsis is 4(Delta). The functional benefit can usually be obtained in the form of improved binocularity and, consequently, better stability of ocular alignment.

  17. Binocular fusion in Panum's limiting case of stereopsis obeys the uniqueness constraint

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhihong; (王志宏); WU; Xinnian; (吴新年); NI; Rui; (倪睿); WANG; Yunjiu; (汪云九)

    2001-01-01

    In the information processing procedure of stereo vision, the uniqueness constraint has been used as one of the constraints to solve the "correspondence problem". While the uniqueness constraint is valid in most cases, whether it is still valid in some particular stimulus configuration (such as Panum's limiting case) has been a problem of widespread debate for a long time. To investigate the problem, we adopted the Panum's limiting case as its basic stimulus configuration, and delved into the phenomenon of binocular fusion from two distinct aspects: visual direction and orientation disparity. The results show that in Panum's limiting case binocular fusion does not comply with the rules governing regular binocular fusion as far as visual direction and orientation disparity are concerned. This indicates that double fusion does not happen in Panum's limiting case and that the uniqueness constraint is still valid.

  18. Binocular fusion in Panum's limiting case of stereopsisobeys the uniqueness constraint

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the information processing procedure of stereo vision, theuniqueness constraint has been used as one of the constraints to solve the "correspondence problem". While the uniqueness constraint is valid in most cases, whether it is still valid in some particular stimulus configuration (such as Panum's limiting case) has been a problem of widespread debate for a long time. To investigate the problem, we adopted the Panum's limiting case as its basic stimulus configuration, and delved into the phenomenon of binocular fusion from two distinct aspects: visual direction and orientation disparity. The results show that in Panum's limiting case binocular fusion does not comply with the rules governing regular binocular fusion as far as visual direction and orientation disparity are concerned. This indicates that double fusion does not happen in Panum's limiting case and that the uniqueness constraint is still valid.

  19. Short-term monocular deprivation strengthens the patched eye's contribution to binocular combination.

    Science.gov (United States)

    Zhou, Jiawei; Clavagnier, Simon; Hess, Robert F

    2013-04-18

    Binocularity is a fundamental property of primate vision. Ocular dominance describes the perceptual weight given to the inputs from the two eyes in their binocular combination. There is a distribution of sensory dominance within the normal binocular population with most subjects having balanced inputs while some are dominated by the left eye and some by the right eye. Using short-term monocular deprivation, the sensory dominance can be modulated as, under these conditions, the patched eye's contribution is strengthened. We address two questions: Is this strengthening a general effect such that it is seen for different types of sensory processing? And is the strengthening specific to pattern deprivation, or does it also occur for light deprivation? Our results show that the strengthening effect is a general finding involving a number of sensory functions, and it occurs as a result of both pattern and light deprivation.

  20. Method used to test the imaging consistency of binocular camera's left-right optical system

    Science.gov (United States)

    Liu, Meiying; Wang, Hu; Liu, Jie; Xue, Yaoke; Yang, Shaodong; Zhao, Hui

    2016-09-01

    To binocular camera, the consistency of optical parameters of the left and the right optical system is an important factor that will influence the overall imaging consistency. In conventional testing procedure of optical system, there lacks specifications suitable for evaluating imaging consistency. In this paper, considering the special requirements of binocular optical imaging system, a method used to measure the imaging consistency of binocular camera is presented. Based on this method, a measurement system which is composed of an integrating sphere, a rotary table and a CMOS camera has been established. First, let the left and the right optical system capture images in normal exposure time under the same condition. Second, a contour image is obtained based on the multiple threshold segmentation result and the boundary is determined using the slope of contour lines near the pseudo-contour line. Third, the constraint of gray level based on the corresponding coordinates of left-right images is established and the imaging consistency could be evaluated through standard deviation σ of the imaging grayscale difference D (x, y) between the left and right optical system. The experiments demonstrate that the method is suitable for carrying out the imaging consistency testing for binocular camera. When the standard deviation 3σ distribution of imaging gray difference D (x, y) between the left and right optical system of the binocular camera does not exceed 5%, it is believed that the design requirements have been achieved. This method could be used effectively and paves the way for the imaging consistency testing of the binocular camera.

  1. [Effect of early surgery in essential infantile esotropia on the quality of binocular vision].

    Science.gov (United States)

    Autrata, R; Hromádková, L; Rehůrek, J

    2002-01-01

    In a retrospective study of 397 children operated in the course of 10 years (1985-1995) on account of essential infantile esotropia the authors evaluate the effect of early surgery implemented before the age of two years on the quality of binocular vision as compared with a later operation. The group of children was divided into three sub-groups. Group A comprised 75 children with the operation during the first six months of life (mean 3.8 months), sub-group B 194 children with the operation at the age of 6-24 months and in group C 128 children operated at the age of 2-6 years (mean 3.56 years). In group A binocular vision was recorded in 80% children (15% superposition, 60% fusion, 5% stereopsy). In groups B binocular vision was recorded in 76% children (18% superposition, 50% fusion, 8% stereopsy). In group C simple binocular vision in the form of superposition was present in 24% and fusion only in 21% children. The results of binocular vision after surgery of essential infantile esotropia are in favour of early surgery, preferably by the age of 6 months, not later than at the age of 2 years. An essential part of comprehensive treatment is active and positive pleoptic and orthoptic care incl. supplementary surgical correction of residual horizontal or vertical deviations. Early surgery of an adequate extent with a safeguarded parallel position of the eyes implies in the long run more frequent achievement of a higher quality of binocular vision incl. stereopsy.

  2. Visión binocular : diagnóstico y tratamiento

    OpenAIRE

    Borràs García, M. Rosa

    1996-01-01

    Este libro está dirigido a todos los profesionales del campo de la optometría que quieran profundizar en la visión binocular. También está indicado para los alumnos de tercer curso de Optometría, tanto en asignaturas troncales como optativas. Sus contenidos están divididos en capítulos que pueden ser leídos de forma independiente, aunque es recomendable comprender el presente texto como una unidad. Su estructura abarca desde las disfunciones binoculares más frecuentes al estrabismo, la amblio...

  3. Voluntary binocular gaze-shifts in the plane of regard: Dynamics of version and vergence

    NARCIS (Netherlands)

    H. Collewijn (Han); D.W. Erkelens (Dirk Willem); R.M. Steinman (Robert)

    1995-01-01

    textabstractWe studied the dynamics of voluntary, horizontal, binocular gaze-shifts between pairs of continuously visible, real three-dimensional targets. Subjects were stabilized on a biteboard to allow full control of target angles, which were made to differ only in distance (pure vergence), only

  4. Quality assessment of stereoscopic 3D image compression by binocular integration behaviors.

    Science.gov (United States)

    Lin, Yu-Hsun; Wu, Ja-Ling

    2014-04-01

    The objective approaches of 3D image quality assessment play a key role for the development of compression standards and various 3D multimedia applications. The quality assessment of 3D images faces more new challenges, such as asymmetric stereo compression, depth perception, and virtual view synthesis, than its 2D counterparts. In addition, the widely used 2D image quality metrics (e.g., PSNR and SSIM) cannot be directly applied to deal with these newly introduced challenges. This statement can be verified by the low correlation between the computed objective measures and the subjectively measured mean opinion scores (MOSs), when 3D images are the tested targets. In order to meet these newly introduced challenges, in this paper, besides traditional 2D image metrics, the binocular integration behaviors-the binocular combination and the binocular frequency integration, are utilized as the bases for measuring the quality of stereoscopic 3D images. The effectiveness of the proposed metrics is verified by conducting subjective evaluations on publicly available stereoscopic image databases. Experimental results show that significant consistency could be reached between the measured MOS and the proposed metrics, in which the correlation coefficient between them can go up to 0.88. Furthermore, we found that the proposed metrics can also address the quality assessment of the synthesized color-plus-depth 3D images well. Therefore, it is our belief that the binocular integration behaviors are important factors in the development of objective quality assessment for 3D images.

  5. Monocular and binocular development in children with albinism, infantile nystagmus syndrome and normal vision

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.

    2013-01-01

    Background/aims: To compare interocular acuity differences, crowding ratios, and binocular summation ratios in 4- to 8-year-old children with albinism (nn=n16), children with infantile nystagmus syndrome (nn=n10), and children with normal vision (nn=n72). Methods: Interocular acuity differences and

  6. Monocular and binocular development in children with albinism, infantile nystagmus syndrome, and normal vision

    NARCIS (Netherlands)

    Huurneman, B.; Boonstra, F.N.

    2013-01-01

    Abstract Background/aims: To compare interocular acuity differences, crowding ratios, and binocular summation ratios in 4- to 8-year-old children with albinism (n = 16), children with infantile nystagmus syndrome (n = 10), and children with normal vision (n = 72). Methods: Interocular acuity differe

  7. The Effects of Sports Vision Training on Binocular Vision Function in Female University Athletes.

    Science.gov (United States)

    Zwierko, Teresa; Puchalska-Niedbał, Lidia; Krzepota, Justyna; Markiewicz, Mikołaj; Woźniak, Jarosław; Lubiński, Wojciech

    2015-12-22

    Binocular vision is the most important visual cue for spatial orientation in many sports. In this study, we investigated how binocular vision was influenced by an eye training program that may be used to improve individual's oculomotor function. The experiment involved twenty-four female student athletes from team ball sports (soccer, basketball, handball). After an initial testing session, 12 participants were randomly allocated to the experimental group. Optometric investigation which included synoptophore testing and a test of dissociated horizontal phoria based on the Maddox method was performed three times: before the experiment, after eight weeks of eye training (3 times a week for 20 minutes), and four weeks after the experiment was terminated. Eye exercise methodology was based on orthoptic, sport and psychological aspects of performance. The phoria screening examination showed that exophoria was the most frequent disorder of binocular vision. Low fusional vergence range was also observed. Following the training period, 3 of the 6 oculomotor variables improved. The greatest effect was observed in near dissociated phoria (χ(2) =14.56, p=0.001 for the right eye; χ(2) =14.757, p=0.001 for the left eye) and fusional convergence (χ(2) =8.522, p=0.014). The results of the retention test conducted four weeks after the experiment confirmed the effectiveness of the vision training program. The results of the study suggest that binocular functions are trainable and can be improved by means of appropriate visual training.

  8. Modeling Visual Symptoms and Visual Skills to Measure Functional Binocular Vision

    Science.gov (United States)

    Powers, M. K.; Fisher, W. P., Jr.; Massof, R. W.

    2016-11-01

    Obtaining a clear image of the world depends on good eye coordination (“binocular vision”). Yet no standard exists by which to determine a threshold for good vs poor binocular vision, as exists for the eye chart and visual acuity. We asked whether data on the signs and symptoms related to binocular vision are sufficiently consistent with children's self-reported visual symptoms to substantiate a construct model of Functional Binocular Vision (FBV), and then whether that model can be used to aggregate clinical and survey observations into a meaningful diagnostic measure. Data on visual symptoms from 1,100 children attending school in Los Angeles were obtained using the Convergence Insufficiency Symptom Survey (CISS); and for more than 300 students in that sample, 35 additional measures were taken, including acuity, cover test near and far, near point of convergence, near point of accommodation, accommodative facility, vergence ranges, tracking ability, and oral reading fluency. A preliminary analysis of data from the 15-item, 5-category CISS and 15 clinical variables from 103 grade school students who reported convergence problems (CISS scores of 16 or higher) suggests that the clinical and survey observations will be optimally combined in a multidimensional model.

  9. Binocular coordination of saccades during reading in children with clinically assessed poor vergence capabilities.

    Science.gov (United States)

    Gaertner, Chrystal; Bucci, Maria Pia; Ajrezo, Layla; Wiener-Vacher, Sylvette

    2013-07-19

    Prior studies have pointed toward a link between the saccadic and vergence systems, coordinating binocular saccadic movements. Recent studies have shown that vergence deficits in children induce poor binocular coordination during saccades, but none of them have studied ocular motility in children during a daily task such as reading. The present study tests whether vergence deficits in children perturb binocular coordination of saccades and fixation during reading. Our second objective was to explore whether vergence training could improve the quality of binocular coordination. Twelve patients (from 7.3 to 13.4 years old) complaining from vertigo but without vestibular and neurological pathology underwent orthoptic tests and were selected for our study when they presented vergence deficits. Eye movements were recorded during a reading task with a Mobile EyeBrain® Tracker video-oculography system. Data were compared to twelve age-matched controls with normal orthoptic values. While there was no statistically significant difference in saccade amplitudes between the two groups (p=0.29), patients showed higher disconjugacy during and after the saccades compared to controls (pbinocular saccade coordination. We suggest that the larger disconjugacy during reading observed in patients before training could be due to poor vergence as initially assessed by orthoptic examination. Such findings support the hypothesis of a tight relationship between the saccadic and vergence systems for controlling the binocular coordination of saccades. The improvement reported after orthoptic training is in line with the hypothesis of an adaptative interaction on a premotor level between the saccadic and vergence system.

  10. Cataract surgery: emotional reactions of patients with monocular versus binocular vision Cirurgia de catarata: aspectos emocionais de pacientes com visão monocular versus binocular

    Directory of Open Access Journals (Sweden)

    Roberta Ferrari Marback

    2012-12-01

    Full Text Available PURPOSE: To analyze emotional reactions related to cataract surgery in two groups of patients (monocular vision - Group 1; binocular vision - Group 2. METHODS: A transversal comparative study was performed using a structured questionnaire from a previous exploratory study before cataract surgery. RESULTS: 206 patients were enrolled in the study, 96 individuals in Group 1 (69.3 ± 10.4 years and 110 in Group 2 (68.2 ± 10.2 years. Most patients in group 1 (40.6% and 22.7% of group 2, reported fear of surgery (pOBJETIVO: Verificar reações emocionais relacionadas à cirurgia de catarata entre pacientes com visão monocular (Grupo 1 e binocular (Grupo 2. MÉTODOS: Foi realizado um estudo tranversal, comparativo por meio de um questionário estruturado respondido por pacientes antes da cirurgia de catarata. RESULTADOS: A amostra foi composta de 96 pacientes no Grupo 1 (69.3 ± 10.4 anos e 110 no Grupo 2 (68.2 ± 10.2 anos. Consideravam apresentar medo da cirugia 40.6% do Grupo 1 e 22.7% do Grupo 2 (p<0.001 e entre as principais causas do medo, a possibilidade de perda da visão, complicações cirúrgicas e a morte durante o procedimento foram apontadas. Os sentimentos mais comuns entre os dois grupos foram dúvidas a cerca dos resultados da cirurgia e o nervosismo diante do procedimento. CONCLUSÃO: Pacientes com visão monocular apresentaram mais medo e dúvidas relacionadas à cirurgia de catarata comparados com aqueles com visão binocular. Portanto, é necessário que os médicos considerem estas reações emocionais e invistam mais tempo para esclarecer os riscos e benefícios da cirurgia de catarata.

  11. Near Point of Convergence Break for Different Age Groups in Turkish Population with Normal Binocular Vision: Normative Data

    OpenAIRE

    Nihat Sayın; Birsen Gökyiğit; Pelin Kaynak; Duygu Tüzün Sayın; Ahmet Demirok; Serpil Akar

    2013-01-01

    Purpose: The purpose of this study was to evaluate the near point of convergence break in Turkish population with normal binocular vision and to obtain the normative data for the near point of convergence break in different age groups. Such database has not been previously reported. Material and Method: In this prospective study, 329 subjects with normal binocular vision (age range, 3-72 years) were evaluated. The near point of convergence break was measured 4 times repeatedly wit...

  12. REDES DE RIVALIDADES Y ALIANZAS ENTRE GRUPOS DE SIMPATIZANTES EN ARGENTINA / Rivalries and alliances networks among supporter’s groups in Argentina.

    Directory of Open Access Journals (Sweden)

    Javier Sebastian Bundio

    2014-12-01

    Full Text Available Con el objetivo de evaluar la influencia de factores tales como la frecuencia de partidos y la cercanía geográfica de instituciones deportivas en el establecimiento de rivalidades y alianzas entre sus grupos de simpatizantes, llevé adelante un Análisis de Redes Sociales a partir de datos para 186 hinchadas argentinas. El conjunto de datos analizados incluye las redes de enemistades (rivalidades mutuamente reconocidas, amistades (afinidades y alianzas mutuamente reconocidas e interacción (cantidad de partidos jugados en los últimos 40 años, y los atributos de pertenencia  provincial y municipal (localización de los estadios. Los resultados obtenidos muestran que la organización regional-nacional de la competencia deportiva, en sus 5 niveles competitivos (Primera A, Nacional B, Primera B, Primera C, Primera D, Argentino A, Argentino B y Argentino C afecta la estructura de las redes de rivalidades y alianzas entre adherentes a equipos de fútbol argentinos. Además detecté una presencia significativa, aunque menor, de tríadas balanceadas de 2 enemistades y 1 amistad lo que permite identificar una “lógica del enemigo común”.   Palabras Claves: fútbol, rivalidad deportiva, alianzas, simpatizantes, análisis de redes sociales.     Abstract In order to evaluate the influence of factors such as frequency of matches played and the geographic proximity of sports institutions in the establishment of rivalries and alliances between soccer supporters, I developed a social network analysis using a dataset for 186 Argentinian hinchadas . The data set includes rivalry's network (rivalries mutually recognized, alliance's network (mutually recognized affinities and alliances and interaction's network (amount of matches played in the last 40 years, and provincial and municipal adscription attributes  (location of stadium. The results show that the regional-national organization of sports competition, in its 5 competitive levels (First A

  13. Research on Extraction of Bottom of Shoe Pattern Based on Binocular Stereo Vision

    Institute of Scientific and Technical Information of China (English)

    MA Xin-wu; GAN Yi; SUN Fu-jia

    2016-01-01

    In order to quickly and efficiently get the information of the bottom of the shoe pattern and spraying trajectory, the paper proposes a method based on binocular stereo vision .After acquiring target image , edge detection based on the canny algorithm , the paper begins stereo matching based on area and characteristics of algorithm.To eliminate false matching points , the paper uses the principle of polar geometry in computer vision . For the purpose of gaining the 3D point cloud of spraying curve , the paper adopts the principle of binocular stereo vision 3D measurement , and then carries on cubic spline curve fitting .By HALCON image processing software programming , it proves the feasibility and effectiveness of the method .

  14. The Role of Binocular Disparity in Rapid Scene and Pattern Recognition

    Directory of Open Access Journals (Sweden)

    Matteo Valsecchi

    2013-04-01

    Full Text Available We investigated the contribution of binocular disparity to the rapid recognition of scenes and simpler spatial patterns using a paradigm combining backward masked stimulus presentation and short-term match-to-sample recognition. First, we showed that binocular disparity did not contribute significantly to the recognition of briefly presented natural and artificial scenes, even when the availability of monocular cues was reduced. Subsequently, using dense random dot stereograms as stimuli, we showed that observers were in principle able to extract spatial patterns defined only by disparity under brief, masked presentations. Comparing our results with the predictions from a cue-summation model, we showed that combining disparity with luminance did not per se disrupt the processing of disparity. Our results suggest that the rapid recognition of scenes is mediated mostly by a monocular comparison of the images, although we can rely on stereo in fast pattern recognition.

  15. VLSI design of 3D display processing chip for binocular stereo displays

    Institute of Scientific and Technical Information of China (English)

    Ge Chenyang; Zheng Nanning

    2010-01-01

    In order to develop the core chip supporting binocular stereo displays for head mounted display(HMD)and glasses-TV,a very large scale integrated(VLSI)design scheme is proposed by using a pipeline architecture for 3D display processing chip(HMD100).Some key techniques including stereo display processing and high precision video scaling based bicubic interpolation,and their hardware implementations which improve the image quality are presented.The proposed HMD100 chip is verified by the field-programmable gate array(FPGA).As one of innovative and high integration SoC chips,HMD100 is designed by a digital and analog mixed circuit.It can support binocular stereo display,has better scaling effect and integration.Hence it is applicable in virtual reality(VR),3D games and other microdisplay domains.

  16. Camera calibration method of binocular stereo vision based on OpenCV

    Science.gov (United States)

    Zhong, Wanzhen; Dong, Xiaona

    2015-10-01

    Camera calibration, an important part of the binocular stereo vision research, is the essential foundation of 3D reconstruction of the spatial object. In this paper, the camera calibration method based on OpenCV (open source computer vision library) is submitted to make the process better as a result of obtaining higher precision and efficiency. First, the camera model in OpenCV and an algorithm of camera calibration are presented, especially considering the influence of camera lens radial distortion and decentering distortion. Then, camera calibration procedure is designed to compute those parameters of camera and calculate calibration errors. High-accurate profile extraction algorithm and a checkboard with 48 corners have also been used in this part. Finally, results of calibration program are presented, demonstrating the high efficiency and accuracy of the proposed approach. The results can reach the requirement of robot binocular stereo vision.

  17. An iPod treatment of amblyopia: an updated binocular approach.

    Science.gov (United States)

    Hess, Robert F; Thompson, B; Black, J M; Machara, G; Zhang, P; Bobier, W R; Cooperstock, J

    2012-02-15

    We describe the successful translation of computerized and space-consuming laboratory equipment for the treatment of suppression to a small handheld iPod device (Apple iPod; Apple Inc., Cupertino, California). A portable and easily obtainable Apple iPod display, using current video technology offers an ideal solution for the clinical treatment of suppression. The following is a description of the iPod device and illustrates how a video game has been adapted to provide the appropriate stimulation to implement our recent antisuppression treatment protocol. One to 2 hours per day of video game playing under controlled conditions for 1 to 3 weeks can improve acuity and restore binocular function, including stereopsis in adults, well beyond the age at which traditional patching is used. This handheld platform provides a convenient and effective platform for implementing the newly proposed binocular treatment of amblyopia in the clinic, home, or elsewhere.

  18. First Results From the Large Binocular Telescope: Deep Photometry of New dSphs

    CERN Document Server

    Coleman, Matthew G

    2007-01-01

    This contribution describes photometry for two Galactic dSphs obtained with the Large Binocular Telescope to a magnitude of ~25.5. Using the Large Binocular Camera, a purpose-built wide-field imager for the LBT, we have examined the structure and star formation histories of two newly-discovered Local Group members, the Hercules dSph and the Leo T dSph/dIrr system. We have constructed a structural map for the Hercules system using three-filter photometry to V ~ 25.5. This is the first deep photometry for this system, and it indicates that Hercules is unusually elongated, possibly indicating distortion due to the Galactic tidal field. We have also derived the first star formation history for the Leo T system, and find that its oldest population of stars (age ~ 13 Gyr) were relatively metal-rich, with [Fe/H] ~ -1.5.

  19. A case of orbital hypertelorism with recovery of binocular vision after surgical treatment.

    Science.gov (United States)

    Okumoto, T; Inoue, Y; Yoshimura, Y

    2012-07-01

    Orbital hypertelorism is defined as an abnormally wide bony interorbital distance. The aims of surgery are both correction of ocular dystopia and cosmetic reconstruction of the nasal crest. Marked improvement of visual function, especially binocular vision, by surgery is not expected. Here we report that surgical treatment unexpectedly resulted in a significant visual improvement for a 13-year-old boy with orbital hypertelorism who also had bilateral cleft lip and palate.

  20. Selective binocular vision loss in two subterranean caviomorph rodents: Spalacopus cyanus and Ctenomys talarum

    Science.gov (United States)

    Vega-Zuniga, T.; Medina, F. S.; Marín, G.; Letelier, J. C.; Palacios, A. G.; Němec, P.; Schleich, C. E.; Mpodozis, J.

    2017-01-01

    To what extent can the mammalian visual system be shaped by visual behavior? Here we analyze the shape of the visual fields, the densities and distribution of cells in the retinal ganglion-cell layer and the organization of the visual projections in two species of facultative non-strictly subterranean rodents, Spalacopus cyanus and Ctenomys talarum, aiming to compare these traits with those of phylogenetically closely related species possessing contrasting diurnal/nocturnal visual habits. S. cyanus shows a definite zone of frontal binocular overlap and a corresponding area centralis, but a highly reduced amount of ipsilateral retinal projections. The situation in C. talarum is more extreme as it lacks of a fronto-ventral area of binocular superposition, has no recognizable area centralis and shows no ipsilateral retinal projections except to the suprachiasmatic nucleus. In both species, the extension of the monocular visual field and of the dorsal region of binocular overlap as well as the whole set of contralateral visual projections, appear well-developed. We conclude that these subterranean rodents exhibit, paradoxically, diurnal instead of nocturnal visual specializations, but at the same time suffer a specific regression of the anatomical substrate for stereopsis. We discuss these findings in light of the visual ecology of subterranean lifestyles. PMID:28150809

  1. Characterization of Visual Symptomatology Associated with Refractive, Accommodative, and Binocular Anomalies

    Directory of Open Access Journals (Sweden)

    Pilar Cacho-Martínez

    2015-01-01

    Full Text Available Purpose. To characterize the symptomatology of refractive, accommodative, and nonstrabismic binocular dysfunctions and to assess the association between dysfunctions and symptoms. Methods. 175 randomised university students were examined. Subjects were given a subjective visual examination with accommodative and binocular tests, evaluating their symptomatology. Accommodative and binocular dysfunctions (AD, BD were diagnosed according to the number of existing clinical signs: suspect AD or BD (one fundamental clinical sign, high suspect (one fundamental + 1 complementary clinical sign, and definite (one fundamental + 2 or more complementary clinical signs. A logistic regression was conducted in order to determine whether there was an association between dysfunctions and symptoms. Results. 78 subjects (44.6% reported any kind of symptoms which were grouped into 18 categories, with “visual fatigue” being the most frequent (20% of the overall complaints. Logistic regression adjusted by the presence of an uncorrected refractive error showed no association between any grade of AD and symptoms. Subjects with BD had more likelihood of having symptoms than without dysfunction group (OR = 3.35, being greater when only definite BD were considered (OR = 8.79. Conclusions. An uncorrected refractive error is a confusion factor when considering AD symptomatology. For BD, the more the number of clinical signs used the greater the likelihood suffering symptoms.

  2. Clinical Outcomes after Binocular Implantation of a New Trifocal Diffractive Intraocular Lens

    Directory of Open Access Journals (Sweden)

    Florian T. A. Kretz

    2015-01-01

    Full Text Available Purpose. To evaluate visual, refractive, and contrast sensitivity outcomes, as well as the incidence of pseudophakic photic phenomena and patient satisfaction after bilateral diffractive trifocal intraocular lens (IOL implantation. Methods. This prospective nonrandomized study included consecutive patients undergoing cataract surgery with bilateral implantation of a diffractive trifocal IOL (AT LISA tri 839MP, Carl Zeiss Meditec. Distance, intermediate, and near visual outcomes were evaluated as well as the defocus curve and the refractive outcomes 3 months after surgery. Photopic and mesopic contrast sensitivity, patient satisfaction, and halo perception were also evaluated. Results. Seventy-six eyes of 38 patients were included; 90% of eyes showed a spherical equivalent within ±0.50 diopters 3 months after surgery. All patients had a binocular uncorrected distance visual acuity of 0.00 LogMAR or better and a binocular uncorrected intermediate visual acuity of 0.10 LogMAR or better, 3 months after surgery. Furthermore, 85% of patients achieved a binocular uncorrected near visual acuity of 0.10 LogMAR or better. Conclusions. Trifocal diffractive IOL implantation seems to provide an effective restoration of visual function for far, intermediate, and near distances, providing high levels of visual quality and patient satisfaction.

  3. The Influence of Binocular Disparity and Motion Parallax on Shape Constancy

    Directory of Open Access Journals (Sweden)

    Junki Maeda

    2011-05-01

    Full Text Available Many studies on shape constancy have been made with 2D shapes presented at varying slants. When object is close, shape constancy is quite good (Lappin & Preble, 1975. Shape constancy declines as the degree of slant increases even with binocular presentation (Massaro, 1973. At large viewing distance, the degree of shape constancy depends on pictorial information (Gogel, 1978. These results suggest that shape constancy is influenced by whether accurate depth is provided. In the current study, the influence of binocular disparity and motion parallax on shape constancy is investigated at near distance. Test stimulus was a square presented at varying slants in a dark room. Subjects responded apparent slant and shape with stereo cue only, with motion cue only, or with the both cues. The apparent slant was veridical with stereo cue only, with motion cue only, and with the both cues. The decline of the shape constancy, however, differed according to cue. The binocular cue yielded shape constancy more than monocular cue.

  4. Statistical normal values of visual parameters that characterize binocular function in children.

    Science.gov (United States)

    Jiménez, R; Pérez, M A; García, J A; González, M D

    2004-11-01

    A wide range of visual parameters used to evaluate binocular function were evaluated in a paediatric population (1056 subjects aged 6-12 years). Mean values are provided for these ages in optometric tests that directly assess the vergence system, horizontal phorias for near and far vision (measured by a modified version of the Thorington method), negative and positive vergence amplitude for near and far vision (step vergence testing), vergence facility (flippers 8 Delta BI/8 Delta BO), and near-point of convergence (penlight push-up technique and red-lens push-up technique), as well as stimulus accommodative convergence/accommodation ratio and stereoacuity (Randot test) which provide an overall evaluation of the vergence, accommodative and oculomotor systems. A statistical comparison (anova and Bonferroni post hoc test) of these values between ages was performed. The differences, although statistically significant, were not clinically meaningful, and therefore we identified two trends in the behaviour of these parameters. For all parameters, except for vergence facility, we established a single mean reference value for the age range studied. The difference between the means for vergence facility indicated the need to divide the population into two age ranges (6-8 and 8-12 years). This study establishes statistical normal values for these parameters in a paediatric population and their means are a valuable instrument for separating children with binocular anomalies from those with normal binocular vision.

  5. Shot Segmentation for Binocular Stereoscopic Video Based on Spatial-Temporal Feature Clustering

    Science.gov (United States)

    Duan, Feng-feng

    2016-12-01

    Shot segmentation is the key to content-based analysis, index and retrieval of binocular stereoscopic video. To solve the problem of low accuracy of stereoscopic video shot segmentation in which the segmentation method of 2D video is used to segment monocular video sequence, and the disadvantages of some stereoscopic video shot segmentation methods, a shot segmentation method for binocular stereoscopic video based on spatial-temporal feature clustering (STFC) is proposed. In the method, the features of color and brightness of left video frames in temporal domain as well as the depth feature acquired by matching of left and right frames in spatial domain is extracted. The feature differences between frames are calculated and quantified. Then the clustering of feature differences in three-dimensional space is executed, and the optimization and iteration of the classes are implemented to achieve the division of shot boundary. The experimental results show that the proposed method can effectively solve the problems of error and omission, especially the inaccuracy of smooth shot detection in binocular stereo video shot segmentation when compared with the latest existing algorithm. The higher accuracy of segmentation can be achieved.

  6. Validation of the Narcissistic Admiration and Rivalry Questionnaire Short Scale (NARQ-S) in Convenience and Representative Samples.

    Science.gov (United States)

    Leckelt, Marius; Wetzel, Eunike; Gerlach, Tanja M; Ackerman, Robert A; Miller, Joshua D; Chopik, William J; Penke, Lars; Geukes, Katharina; Küfner, Albrecht C P; Hutteman, Roos; Richter, David; Renner, Karl-Heinz; Allroggen, Marc; Brecheen, Courtney; Campbell, W Keith; Grossmann, Igor; Back, Mitja D

    2017-03-02

    Due to increased empirical interest in narcissism across the social sciences, there is a need for inventories that can be administered quickly while also reliably measuring both the agentic and antagonistic aspects of grandiose narcissism. In this study, we sought to validate the factor structure, provide representative descriptive data and reliability estimates, assess the reliability across the trait spectrum, and examine the nomological network of the short version of the Narcissistic Admiration and Rivalry Questionnaire (NARQ-S; Back et al., 2013). We used data from a large convenience sample (total N = 11,937) as well as data from a large representative sample (total N = 4,433) that included responses to other narcissism measures as well as related constructs, including the other Dark Triad traits, Big Five personality traits, and self-esteem. Confirmatory factor analysis and item response theory were used to validate the factor structure and estimate the reliability across the latent trait spectrum, respectively. Results suggest that the NARQ-S shows a robust factor structure and is a reliable and valid short measure of the agentic and antagonistic aspects of grandiose narcissism. We also discuss future directions and applications of the NARQ-S as a short and comprehensive measure of grandiose narcissism. (PsycINFO Database Record

  7. Corneal Transplantation in Disease Affecting Only One Eye: Does It Make a Difference to Habitual Binocular Viewing?

    Directory of Open Access Journals (Sweden)

    Praveen K Bandela

    Full Text Available Clarity of the transplanted tissue and restoration of visual acuity are the two primary metrics for evaluating the success of corneal transplantation. Participation of the transplanted eye in habitual binocular viewing is seldom evaluated post-operatively. In unilateral corneal disease, the transplanted eye may remain functionally inactive during binocular viewing due to its suboptimal visual acuity and poor image quality, vis-à-vis the healthy fellow eye.This study prospectively quantified the contribution of the transplanted eye towards habitual binocular viewing in 25 cases with unilateral transplants [40 yrs (IQR: 32-42 yrs and 25 age-matched controls [30 yrs (25-37 yrs]. Binocular functions including visual field extent, high-contrast logMAR acuity, suppression threshold and stereoacuity were assessed using standard psychophysical paradigms. Optical quality of all eyes was determined from wavefront aberrometry measurements. Binocular visual field expanded by a median 21% (IQR: 18-29% compared to the monocular field of cases and controls (p = 0.63. Binocular logMAR acuity [0.0 (0.0-0.0] almost always followed the fellow eye's acuity [0.00 (0.00 --0.02] (r = 0.82, independent of the transplanted eye's acuity [0.34 (0.2-0.5] (r = 0.04. Suppression threshold and stereoacuity were poorer in cases [30.1% (13.5-44.3%; 620.8 arc sec (370.3-988.2 arc sec] than in controls [79% (63.5-100%; 16.3 arc sec (10.6-25.5 arc sec] (p<0.001. Higher-order wavefront aberrations of the transplanted eye [0.34 μ (0.21-0.51 μ] were higher than the fellow eye [0.07 μ (0.05-0.11 μ] (p<0.001 and their reduction with RGP contact lenses [0.09 μ (0.08-0.12 μ] significantly improved the suppression threshold [65% (50-72%] and stereoacuity [56.6 arc sec (47.7-181.6 arc sec] (p<0.001.In unilateral corneal disease, the transplanted eye does participate in gross binocular viewing but offers limited support to fine levels of binocularity. Improvement in the transplanted

  8. Two Eyes Are Better Than One—Binocular Summation of Dark Vision in Healthy Individuals and Patients with Chronic Respiratory Disease

    OpenAIRE

    Thylefors, Joakim; Havelius, Ulf

    2014-01-01

    We compared monocular and binocular absolute thresholds of dark adaptation in two separate study populations. Eighteen healthy individuals (Group A) and 13 patients with chronic respiratory insufficiency (Group B) were examined three times each by computerised dark adaptometry with simultaneous but separate recordings from each eye and binocularly. The respiratory patients received oxygen supplement at visits 1 and 3. In Group A, at all three visits, binocular dark adaptation was significantl...

  9. Binocular Glaucomatous Visual Field Loss and Its Impact on Visual Exploration - A Supermarket Study

    Science.gov (United States)

    Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

    2014-01-01

    Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as “passed” or “failed” with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p<0.001). Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD) area than patients who failed (t-test, p<0.05). According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a “time-effective” compensatory mechanism during the present supermarket task. PMID:25162522

  10. Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.

    Directory of Open Access Journals (Sweden)

    Katrin Sippel

    Full Text Available Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii to identify factors influencing the performance, and (iii to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP, and ten healthy-sighted control subjects (GC were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item. Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p < 0.001. Furthermore, patients who passed the task showed a significantly higher number of glances towards the visual field defect (VFD area than patients who failed (t-test, p < 0.05. According to these results, glaucoma patients with defects in the binocular visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.

  11. A Standardized Procedure and Normative Values for Measuring Binocular Dynamic Visual Acuity

    Directory of Open Access Journals (Sweden)

    Amanda Miskewicz-Zastrow, OD

    2015-04-01

    Full Text Available Background: Binocular dynamic visual acuity (BDVA is the ability to differentiate fine details in a moving object such as seams on a pitched baseball or the rotation of a tennis ball, both of which can travel up to speeds exceeding 100 miles per hour. BDVA is one of many binocular visual measurements to examine binocular function. This study was designed to provide a standardized procedure for measuring BDVA and normal values for a sample population. Previous studies have used different techniques for measurement, and thus have no normative data for comparison. Methods: The BCVA attachment to the Bernell Rotation Trainer was used to measure BDVA in 22 subjects (10 females and 12 males between the ages of 23 and 30. Only subjects with a refractive error between +1.00 D and -7.00 D (spherical equivalent and with best corrected visual acuity of 20/20 or better were able to participate in the study. BDVA was recorded at three different rotation speeds (29 RPM, 24 RPM, and 16 RPM. At each RPM, accuracy and the time to completion of all nine lines were measured. The subjects were also asked to complete a questionnaire designed to evaluate factors that may influence the BDVA results. Results: A decrease in RPM resulted in a corresponding decrease in the subject’s completion time and an increase in accuracy. The same trend was seen when comparing males and females; however, the females’ accuracy was lower and the time was greater when compared to the males, but these were not statistically significant. Conclusions: This was the first study designed to use the Bernell Rotation Trainer to quantitatively measure BDVA in a standardized way. Our results showed similar trends in both males and females. In addition, this study provides a strong foundation for future research, such as comparing BDVA of athletes and non-athletes, or comparing athletes with different skill levels, or comparing athletes who participate in different sports.

  12. On-site calibration method for outdoor binocular stereo vision sensors

    Science.gov (United States)

    Liu, Zhen; Yin, Yang; Wu, Qun; Li, Xiaojing; Zhang, Guangjun

    2016-11-01

    Using existing calibration methods for binocular stereo vision sensors (BSVS), it is very difficult to extract target characteristic points in outdoor environments under complex light conditions. To solve the problem, an online calibration method for BSVS based a double parallel cylindrical target and a line laser projector is proposed in this paper. The intrinsic parameters of two cameras are calibrated offline. Laser strips on the double parallel cylindrical target are mediated to calibrate the configuration parameters of BSVS. The proposed method only requires images of laser strips on the target and is suitable for the calibration of BSVS in outdoor environments. The effectiveness of the proposed method is validated through physical experiments.

  13. Influencia de las aberraciones en visión binocular mediante el uso de sistemas de óptica adaptativa= Influence of aberrations on binocular vision by means of adaptive optics instruments

    OpenAIRE

    Schwarz, Christina

    2013-01-01

    El objetivo de esta tesis ha sido obtener una mejor comprensión de la influencia que tienen las aberraciones en la visión binocular mediante el uso de le tecnología de óptica adaptativa. Para este fin, se diseñó y construyó un simulador visual binocular de óptica adaptativa capaz de controlar de manera precisa la función pupila compleja en ambos ojos simultáneamente. El sistema se basa en el uso de moduladores espaciales de cristal líquido, lo que permite una alta resolución en planos conjuga...

  14. Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction

    DEFF Research Database (Denmark)

    Schow, Trine; Harris, Paul; Teasdale, Thomas William;

    2016-01-01

    Trine Schow, Paul Harris, Thomas William Teasdale, Morten Arendt Rasmussen. Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction. NeuroRehabilitation. 2016 Apr 6;38(4):331-41. doi: 10.3233/NRE-161324.......Trine Schow, Paul Harris, Thomas William Teasdale, Morten Arendt Rasmussen. Evaluation of a four month rehabilitation program for stroke patients with balance problems and binocular visual dysfunction. NeuroRehabilitation. 2016 Apr 6;38(4):331-41. doi: 10.3233/NRE-161324....

  15. Fabrication of NaYF4:Yb,Er Nanoprobes for Cell Imaging Directly by Using the Method of Hydrion Rivalry Aided by Ultrasonic

    Science.gov (United States)

    Li, Zhihua; Miao, Haixia; Fu, Ying; Liu, Yuxiang; Zhang, Ran; Tang, Bo

    2016-10-01

    A novel method of fabricating water-soluble bio-probes with ultra-small size such as NaYF4:Yb,Er (18 nm), NaGdF4:Yb,Er (8 nm), CaF2:Yb,Er (10 nm), PbS (7 nm), and ZnS (12 nm) has been developed to provide for the solubility switch of nanoparticles from oil-soluble to water-soluble in terms of hydrion rivalry aided by ultrasonic. Using NaYF4:Yb,Er (18 nm) as an example, we evaluate the properties of as-prepared water-soluble nanoparticles (NPs) by using thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), zeta potential ( ζ) testing, and 1H nuclear magnetic resonance (1HNMR). The measured ζ value shows that the newly prepared hydrophilic NaYF4:Yb,Er NPs are the positively charged particles. Acting as reactive electrophilic moiety, the freshly prepared hydrophilic NaYF4:Yb,Er NPs have carried out the coupling with amino acids and fluorescence labeling and imaging of HeLa cells directly. Experiments indicate that the method of hydrion rivalry aided by ultrasonic provides a simple and novel opportunity to transform hydrophobic NPs into hydrophilic NPs with good reactivity, which can be imaging some specific biological targets directly.

  16. On-sky single-mode fiber coupling measurements at the Large Binocular Telescope

    CERN Document Server

    Bechter, Andrew; Ketterer, Ryan; Crepp, Justin R; Reynolds, Robert O; Bechter, Eric; Hinz, Philip; Pedichini, Fernando; Foley, Michael; Runburg, Elliott; Onuma, Eleanya; Gaudi, Scott; Micela, Giuseppina; Pagano, Isabella; Woodward, Charles E

    2016-01-01

    The demonstration of efficient single-mode fiber (SMF) coupling is a key requirement for the development of a compact, ultra-precise radial velocity (RV) spectrograph. iLocater is a next generation instrument for the Large Binocular Telescope (LBT) that uses adaptive optics (AO) to inject starlight into a SMF. In preparation for commissioning iLocater, a prototype SMF injection system was installed and tested at the LBT in the Y-band (0.970-1.065 $\\mu$m). This system was designed to verify the capability of the LBT AO system as well as characterize on-sky SMF coupling efficiencies. SMF coupling was measured on stars with variable airmasses, apparent magnitudes, and seeing conditions for six half-nights using the Large Binocular Telescope Interferometer. We present the overall optical and mechanical performance of the SMF injection system, including details of the installation and alignment procedure. A particular emphasis is placed on analyzing the instrument's performance as a function of telescope elevation...

  17. Parts-based stereoscopic image assessment by learning binocular manifold color visual properties

    Science.gov (United States)

    Xu, Haiyong; Yu, Mei; Luo, Ting; Zhang, Yun; Jiang, Gangyi

    2016-11-01

    Existing stereoscopic image quality assessment (SIQA) methods are mostly based on the luminance information, in which color information is not sufficiently considered. Actually, color is part of the important factors that affect human visual perception, and nonnegative matrix factorization (NMF) and manifold learning are in line with human visual perception. We propose an SIQA method based on learning binocular manifold color visual properties. To be more specific, in the training phase, a feature detector is created based on NMF with manifold regularization by considering color information, which not only allows parts-based manifold representation of an image, but also manifests localized color visual properties. In the quality estimation phase, visually important regions are selected by considering different human visual attention, and feature vectors are extracted by using the feature detector. Then the feature similarity index is calculated and the parts-based manifold color feature energy (PMCFE) for each view is defined based on the color feature vectors. The final quality score is obtained by considering a binocular combination based on PMCFE. The experimental results on LIVE I and LIVE Π 3-D IQA databases demonstrate that the proposed method can achieve much higher consistency with subjective evaluations than the state-of-the-art SIQA methods.

  18. The relationship between binocular vision symptoms and near point of convergence

    Directory of Open Access Journals (Sweden)

    Momeni-Moghaddam Hamed

    2013-01-01

    Full Text Available Aim and Background: Due to the relatively high prevalence of binocular vision anomalies, a regular examination including tests for assessment and determination of these anomalies is necessary. The aim of this study was to assess the relationship between near point of convergence (NPC and near binocular vision symptoms and finding of an NPC cutoff point for symptoms in university students. Materials and Methods: In this cross-sectional study, 124 students of different majors of Zahedan University of Medical Sciences were randomly selected. If they met the inclusion criteria, they were divided into two groups (symptomatic and asymptomatic according to the convergence insufficiency symptom survey questionnaire. For NPC measurement, a small isolated letter "E" of approximately 20/30 size on a metal rod was used. After data collection, data were analyzed in SPSS.17 software (SPSS for Windows, SPSS Inc., Chicago, IL using descriptive and analytical statistics, including Mann-Whitney U test and receiver operating characteristic (ROC curve. Results: The mean NPC findings in the symptomatic and asymptomatic groups were 11.7 ± 5.0 and 8.4 ± 3.4 cm, respectively, with a significant difference between the two groups (P < 0.001. The ROC curve suggests an NPC cutoff point of 9.5 cm for the presence of symptoms with the testing procedures used in this study. Conclusion : The determination of NPC is helpful in the differentiation of symptomatic from asymptomatic subjects.

  19. Enhancement display of veins distribution based on binocular vision and image fusion technology

    Science.gov (United States)

    Liu, Peng; Di, Si; Jin, Jian; Bai, Liping

    2014-11-01

    The capture and display of veins distribution is an important issue for some applications, such as medical diagnosis and identification. Therefore, it has become a popular topic in the field of biomedical imaging. Usually, people capture the veins distribution by infrared imaging, but the display result is similar with that of a gray picture and the color and details of skin cannot be remained. To some degree, it is unreal for doctors. In this paper, we develop a binocular vision system to carry out the enhancement display of veins under the condition of keeping actual skin color. The binocular system is consisted of two adjacent cameras. A visible band filter and an infrared band filter are placed in front of the two lenses, respectively. Therefore, the pictures of visible band and infrared band can be captured simultaneously. After that, a new fusion process is applied to the two pictures, which related to histogram mapping, principal component analysis (PCA) and modified bilateral filter fusion. The final results show that both the veins distribution and the actual skin color of the back of the hand can be clearly displayed. Besides, correlation coefficient, average gradient and average distortion are selected as the parameters to evaluate the image quality. By comparing the parameters, it is evident that our novel fusion method is prior to some popular fusion methods such as Gauss filter fusion, Intensity-hue-saturation (HIS) fusion and bilateral filter fusion.

  20. Research on key technology of yacht positioning based on binocular parallax

    Science.gov (United States)

    Wang, Wei; Wei, Ping; Liu, Zengzhi

    2016-10-01

    Yacht has become a fashionable way for entertainment. However, to obtain the precise location of a yacht docked at a port has become one of the concerns of a yacht manager. To deal with this issue, we adopt a positioning method based on the principle of binocular parallax and background difference in this paper. Binocular parallax uses cameras to get multi-dimensional perspective of the yacht based on geometric principle of imaging. In order to simplify the yacht localization problem, we install LED light indicator as the key point on a yacht. And let it flash at a certain frequency during day time and night time. After getting the distance between the LED and the cameras, locating the yacht is easy. Compared with other traditional positioning methods, this method is simpler and easier to implement. In this paper, we study the yacht positioning method using the LED indicator. Simulation experiment is done for a yacht model in the distance of 3 meters. The experimental result shows that our method is feasible and easy to implement with a small 15% positioning error.

  1. An Active Stereo Vision System Based on Neural Pathways of Human Binocular Motor System

    Institute of Scientific and Technical Information of China (English)

    Yu-zhang Gu; Makoto Sato; Xiao-lin Zhang

    2007-01-01

    An active stereo vision system based on a model of neural pathways of human binocular motor system is proposed. With this model, it is guaranteed that the two cameras of the active stereo vision system can keep their lines of sight fixed on the same target object during smooth pursuit. This feature is very important for active stereo vision systems, since not only 3D reconstruction needs the two cameras have an overlapping field of vision, but also it can facilitate the 3D reconstruction algorithm. To evaluate the effectiveness of the proposed method, some software simulations are done to demonstrate the same target tracking characteristic in a virtual environment apt to mistracking easily. Here, mistracking means two eyes track two different objects separately. Then the proposed method is implemented in our active stereo vision system to perform real tracking task in a laboratory scene where several persons walk self-determining. Before the proposed model is implemented in the system, mistracking occurred frequently. After it is enabled, mistracking never occurred. The result shows that the vision system based on neural pathways of human binocular motor system can reliably avoid mistracking.

  2. Optoelectronic stereoscopic device for diagnostics, treatment, and developing of binocular vision

    Science.gov (United States)

    Pautova, Larisa; Elkhov, Victor A.; Ovechkis, Yuri N.

    2003-08-01

    Operation of the device is based on alternative generation of pictures for left and right eyes on the monitor screen. Controller gives pulses on LCG so that shutter for left or right eye opens synchronously with pictures. The device provides frequency of switching more than 100 Hz, and that is why the flickering is absent. Thus, a separate demonstration of images to the left eye or to the right one in turn is obtained for patients being unaware and creates the conditions of binocular perception clsoe to natural ones without any additional separation of vision fields. LC-cell transfer characteristic coodination with time parameters of monitor screen has enabled to improve stereo image quality. Complicated problem of computer stereo images with LC-glasses is so called 'ghosts' - noise images that come to blocked eye. We reduced its influence by adapting stereo images to phosphor and LC-cells characteristics. The device is intended for diagnostics and treatment of stabismus, amblyopia and other binocular and stereoscopic vision impairments, for cultivating, training and developing of stereoscopic vision, for measurements of horizontal and vertical phoria, phusion reserves, the stereovision acuity and some else, for fixing central scotoma borders, as well as suppression scotoma in strabismus too.

  3. Current Status of the Facility Instrumentation Suite at The Large Binocular Telescope Observatory

    CERN Document Server

    Rothberg, Barry; Edwards, Michelle L; Hill, John M; Thompson, David; Veillet, Christian; Wagner, R Mark

    2016-01-01

    We review the current status of the facility instrumentation for the Large Binocular Telescope (LBT). The LBT has 2x 8.4m primary mirrors on a single mount with an effective collecting area of 11.8m or 23m when interferometrically combined. The facility instruments are: 1) the Large Binocular Cameras (LBCs), each with a 23'x25' field of view (FOV). The blue and red optimized optical LBCs are mounted at the prime focus of the left and right primary mirrors, respectively. The filter suite of the two LBCs covers 0.3-1.1{\\mu}m, including the new TiO (0.78{\\mu}m) and CN (0.82{\\mu}m) filters; 2) the Multi-Object Double Spectrograph (MODS), two identical optical spectrographs each mounted at a straight through f/15 Gregorian mount. MODS-1 & -2 can do imaging with Sloan filters and medium resolution (R~2000) spectroscopy, each with 24 interchangeable masks (multi-object or longslit) over a 6'x6' FOV. Each MODS is capable of blue (0.32-0.6{\\mu}m) and red (0.5-1.05{\\mu}m) wavelength only coverage or, using a dichro...

  4. Binocular saccade coordination in reading and visual search: a developmental study in typical reader and dyslexic children.

    Science.gov (United States)

    Seassau, Magali; Gérard, Christophe Loic; Bui-Quoc, Emmanuel; Bucci, Maria Pia

    2014-01-01

    Studies dealing with developmental aspects of binocular eye movement behavior during reading are scarce. In this study we have explored binocular strategies during reading and visual search tasks in a large population of dyslexic and typical readers. Binocular eye movements were recorded using a video-oculography system in 43 dyslexic children (aged 8-13) and in a group of 42 age-matched typical readers. The main findings are: (i) ocular motor characteristics of dyslexic children are impaired in comparison to those reported in typical children in reading task; (ii) a developmental effect exists in reading in control children, in dyslexic children the effect of development was observed only on fixation durations; and (iii) ocular motor behavior in the visual search tasks is similar for dyslexic children and for typical readers, except for the disconjugacy during and after the saccade: dyslexic children are impaired in comparison to typical children. Data reported here confirms and expands previous studies on children's reading. Both reading skills and binocular saccades coordination improve with age in typical readers. The atypical eye movement's patterns observed in dyslexic children suggest a deficiency in the visual attentional processing as well as an impairment of the ocular motor saccade and vergence systems interaction.

  5. A high precision instrument to measure angular and binocular deviation introduced by aircraft windscreens by using a shadow casting technique

    Energy Technology Data Exchange (ETDEWEB)

    Shivananju, B. N.; Yamdagni, S. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Vasu, R. M. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Applied Photonics Initiative, Indian Institute of Science, Bangalore 560012 (India); Asokan, S. [Department of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012 (India); Applied Photonics Initiative, Indian Institute of Science, Bangalore 560012 (India); Robert Bosch Centre for Cyber Physical Systems, Indian Institute of Science, Bangalore 560012 (India)

    2012-12-15

    Objects viewed through transparent sheets with residual non-parallelism and irregularity appear shifted and distorted. This distortion is measured in terms of angular and binocular deviation of an object viewed through the transparent sheet. The angular and binocular deviations introduced are particularly important in the context of aircraft windscreens and canopies as they can interfere with decision making of pilots especially while landing, leading to accidents. In this work, we have developed an instrument to measure both the angular and binocular deviations introduced by transparent sheets. This instrument is especially useful in the qualification of aircraft windscreens and canopies. It measures the deviation in the geometrical shadow cast by a periodic dot pattern trans-illuminated by the distorted light beam from the transparent test specimen compared to the reference pattern. Accurate quantification of the shift in the pattern is obtained by cross-correlating the reference shadow pattern with the specimen shadow pattern and measuring the location of the correlation peak. The developed instrument is handy to use and computes both angular and binocular deviation with an accuracy of less than {+-}0.1 mrad ( Almost-Equal-To 0.036 mrad) and has an excellent repeatability with an error of less than 2%.

  6. A near-ultraviolet view of the Inner Region of M31 with the Large Binocular Telescope

    CERN Document Server

    Beccari, G; Clementini, G; Federici, L; Pecci, F Fusi; Galleti, S; Montegriffo, P; Giallongo, E; Ragazzoni, R; Grazian, A; Baruffolo, A; De Santis, C; Diolaiti, E; Di Paola, A; Farinato, J; Fontana, A; Gallozzi, S; Gasparo, F; Gentile, G; Green, R; Hill, J; Kuhn, O; Menci, N; Pedichini, F Pasian F; Smareglia, R; Speziali, R; Testa, V; Thompson, D; Vernet, E; Wagner, R M

    2007-01-01

    We present a 900 sec, wide-field U image of the inner region of the Andromeda galaxy obtained during the commissioning of the blue channel of the Large Binocular Camera mounted on the prime focus of the Large Binocular Telescope. Relative photometry and absolute astrometry of individual sources in the image was obtained along with morphological parameters aimed at discriminating between stars and extended sources, e.g. globular clusters. The image unveils the near-ultraviolet view of the inner ring of star formation recently discovered in the infrared by the Spitzer Space Telescope and shows in great detail the fine structure of the dust lanes associated with the galaxy inner spiral arms. The capabilities of the blue channel of the Large Binocular Camera at the Large Binocular Telescope (LBC-Blue) are probed by direct comparison with ultraviolet GALEX observations of the same region in M31. We discovered 6 new candidate stellar clusters in this high-background region of M31. We also recovered 62 bona-fide glo...

  7. Binocular Saccade Coordination in Reading and Visual Search: A Developmental Study in Typical Reader and Dyslexic Children

    Directory of Open Access Journals (Sweden)

    Magali eSeassau

    2014-10-01

    Full Text Available Studies dealing with developmental aspects of binocular eye movement behavior during reading are scarce. In this study we have explored binocular strategies during reading and visual search tasks in a large population of dyslexic and typical readers. Binocular eye movements were recorded using a video-oculography system in 43 dyslexic children (aged 8 to 13 and in a group of 42 age-matched typical readers. The main findings are (i ocular motor characteristics of dyslexic children are impaired in comparison to those reported in typical children in reading task ; (ii a developmental effect exists in reading in control children; in dyslexic children the effect of development was observed only on fixation durations ; (iii ocular motor behavior in the visual search tasks is similar for dyslexic children and for typical readers, except for the disconjugacy during and after the saccade: dyslexic children are impaired in comparison to typical children. Data reported here confirms and expands previous studies on children’s reading. Both reading skills and binocular saccades coordination improve with age in typical readers. The atypical eye movement’s patterns observed in dyslexic children suggest a deficiency in the visual attentional processing as well as an impairment of the ocular motor saccade and vergence systems interaction.

  8. An overview and the current status of instrumentation at the Large Binocular Telescope Observatory

    Science.gov (United States)

    Wagner, R. Mark; Edwards, Michelle L.; Kuhn, Olga; Thompson, David; Veillet, Christian

    2014-07-01

    An overview of instrumentation for the Large Binocular Telescope (LBT) is presented. Optical instrumentation includes the Large Binocular Camera (LBC), a pair of wide-field (24' × 24') mosaic CCD imagers at the prime focus, and the Multi-Object Double Spectrograph (MODS), a pair of dual-beam blue-red optimized long-slit spectrographs mounted at the left and right direct F/15 Gregorian foci incorporating multiple slit masks for multi-object spectroscopy over a 6' field and spectral resolutions of up to 2000. Infrared instrumentation includes the LBT Near-IR Spectrometer (LUCI), a modular near-infrared (0.9-2.5 μm) imager and spectrograph pair mounted at the left and right front-bent F/15 Gregorian foci and designed for seeing-limited (FOV: 4' × 4') imaging, long-slit spectroscopy, and multi-object spectroscopy utilizing cooled slit masks and diffraction limited (FOV: 0'.5 x 0'.5) imaging and long-slit spectroscopy. Strategic instruments under development that can utilize the full 23 m baseline of the LBT include an interferometric cryogenic beam combiner with near-infrared and thermal-infrared instruments for Fizeau imaging and nulling interferometry (LBTI) and an optical bench near- infrared beam combiner utilizing multi-conjugate adaptive optics for high angular resolution and sensitivity (LINC-NIRVANA). LBTI is currently undergoing commissioning and performing science observations on the LBT utilizing the installed adaptive secondary mirrors in both single-sided and two-sided beam combination modes. In addition, a fiber-fed bench spectrograph (PEPSI) capable of ultra high resolution spectroscopy and spectropolarimetry (R = 40,000-300,000) will be available as a principal investigator instrument. Installation and testing of the bench spectrograph will begin in July 2014. Over the past four years the LBC pair, LUCI1, and MODS1 have been commissioned and are now scheduled for routine partner science observations. Both LUCI2 and MODS2 passed their laboratory

  9. Optimized stereo matching in binocular three-dimensional measurement system using structured light.

    Science.gov (United States)

    Liu, Kun; Zhou, Changhe; Wei, Shengbin; Wang, Shaoqing; Fan, Xin; Ma, Jianyong

    2014-09-10

    In this paper, we develop an optimized stereo-matching method used in an active binocular three-dimensional measurement system. A traditional dense stereo-matching algorithm is time consuming due to a long search range and the high complexity of a similarity evaluation. We project a binary fringe pattern in combination with a series of N binary band limited patterns. In order to prune the search range, we execute an initial matching before exhaustive matching and evaluate a similarity measure using logical comparison instead of a complicated floating-point operation. Finally, an accurate point cloud can be obtained by triangulation methods and subpixel interpolation. The experiment results verify the computational efficiency and matching accuracy of the method.

  10. The Search for Failed Supernovae with the Large Binocular Telescope: Constraints from 7 Years of Data

    CERN Document Server

    Adams, S M; Gerke, J R; Stanek, K Z

    2016-01-01

    We report updated results for the first 7 years of our program to monitor 27 galaxies within 10 Mpc using the Large Binocular Telescope to search for failed supernovae -- core-collapses of massive stars that form black holes without luminous supernovae. In the new data, we identify no new compelling candidates and confirm the existing candidate. Given the 6 successful core-collapse SNe in the sample and one likely failed SN, the implied fraction of core-collapses that result in failed SNe is $f = 0.14^{+0.33}_{-0.10}$ at 90% confidence. If the current candidate is a failed SN, the fraction of failed SN naturally explains the missing high-mass RSG SN progenitors and the black hole mass function. If the current candidate is ultimately rejected, the data implies a 90% confidence upper limit on the failed SN fraction of $f < 0.35$.

  11. Application of binocular vision system to face detection and tracking in service robot

    Science.gov (United States)

    Qian, Junfeng; Ma, Shiwei; Xu, Yulin; Li, Xin; Shen, Yujie

    2012-01-01

    A binocular vision system and its application to face detection and tracking in robot is introduced in this paper. With the vision system, the robot can do face detection, identification, recognition and tracking. The face area is detected in realtime by using AdaBoost algorithm. And a method is proposed with which a real face can be distinguished from a picture one by using skin color information and depth data. A specific face can be recognized by comparing the principal components of the current face to those of the known individuals in a face database built in advance. Finally, the robot can track a specified face according to depth of the face and position of a face rectangle in the frame. Experiment results are given and discussed.

  12. Co-phasing the Large Binocular Telescope: status and performance of LBTI/PHASECam

    CERN Document Server

    Defrère, D; Downey, E; Ashby, D; Bailey, V; Brusa, G; Christou, J; Danchi, W C; Grenz, P; Hill, J M; Hoffmann, W F; Leisenring, J; Lozi, J; McMahon, T; Mennesson, B; Millan-Gabet, R; Montoya, M; Powell, K; Skemer, A; Vaitheeswaran, V; Vaz, A; Veillet, C

    2015-01-01

    The Large Binocular Telescope Interferometer is a NASA-funded nulling and imaging instrument designed to coherently combine the two 8.4-m primary mirrors of the LBT for high-sensitivity, high-contrast, and high-resolution infrared imaging (1.5-13 um). PHASECam is LBTI's near-infrared camera used to measure tip-tilt and phase variations between the two AO-corrected apertures and provide high-angular resolution observations. We report on the status of the system and describe its on-sky performance measured during the first semester of 2014. With a spatial resolution equivalent to that of a 22.8-meter telescope and the light-gathering power of single 11.8-meter mirror, the co-phased LBT can be considered to be a forerunner of the next-generation extremely large telescopes (ELT).

  13. Co-Phasing the Large Binocular Telescope:. [Status and Performance of LBTI-PHASECam

    Science.gov (United States)

    Defrere, D.; Hinz, P.; Downey, E.; Ashby, D.; Bailey, V.; Brusa, G.; Christou, J.; Danchi, W. C.; Grenz, P.; Hill, J. M.; Hoffmann, W. F.; Leisenring, J.; Lozi, J.; McMahon, T.; Mennesson, B.; Millan-Gabet, R.; Montoya, M.; Powell, K.; Skemer, A.; Vaitheeswaran, V.; Vaz, A.; Veillet, C.

    2014-01-01

    The Large Binocular Telescope Interferometer is a NASA-funded nulling and imaging instrument designed to coherently combine the two 8.4-m primary mirrors of the LBT for high-sensitivity, high-contrast, and high-resolution infrared imaging (1.5-13 micrometer). PHASECam is LBTI's near-infrared camera used to measure tip-tilt and phase variations between the two AO-corrected apertures and provide high-angular resolution observations. We report on the status of the system and describe its on-sky performance measured during the first semester of 2014. With a spatial resolution equivalent to that of a 22.8-meter telescope and the light-gathering power of single 11.8-meter mirror, the co-phased LBT can be considered to be a forerunner of the next-generation extremely large telescopes (ELT).

  14. An active system for visually-guided reaching in 3D across binocular fixations.

    Science.gov (United States)

    Martinez-Martin, Ester; del Pobil, Angel P; Chessa, Manuela; Solari, Fabio; Sabatini, Silvio P

    2014-01-01

    Based on the importance of relative disparity between objects for accurate hand-eye coordination, this paper presents a biological approach inspired by the cortical neural architecture. So, the motor information is coded in egocentric coordinates obtained from the allocentric representation of the space (in terms of disparity) generated from the egocentric representation of the visual information (image coordinates). In that way, the different aspects of the visuomotor coordination are integrated: an active vision system, composed of two vergent cameras; a module for the 2D binocular disparity estimation based on a local estimation of phase differences performed through a bank of Gabor filters; and a robotic actuator to perform the corresponding tasks (visually-guided reaching). The approach's performance is evaluated through experiments on both simulated and real data.

  15. An Active System for Visually-Guided Reaching in 3D across Binocular Fixations

    Directory of Open Access Journals (Sweden)

    Ester Martinez-Martin

    2014-01-01

    Full Text Available Based on the importance of relative disparity between objects for accurate hand-eye coordination, this paper presents a biological approach inspired by the cortical neural architecture. So, the motor information is coded in egocentric coordinates obtained from the allocentric representation of the space (in terms of disparity generated from the egocentric representation of the visual information (image coordinates. In that way, the different aspects of the visuomotor coordination are integrated: an active vision system, composed of two vergent cameras; a module for the 2D binocular disparity estimation based on a local estimation of phase differences performed through a bank of Gabor filters; and a robotic actuator to perform the corresponding tasks (visually-guided reaching. The approach’s performance is evaluated through experiments on both simulated and real data.

  16. Simultaneous perimeter measurement for 3D object with a binocular stereo vision measurement system

    Science.gov (United States)

    Peng, Zhao; Guo-Qiang, Ni

    2010-04-01

    A simultaneous measurement scheme for multiple three-dimensional (3D) objects' surface boundary perimeters is proposed. This scheme consists of three steps. First, a binocular stereo vision measurement system with two CCD cameras is devised to obtain the two images of the detected objects' 3D surface boundaries. Second, two geodesic active contours are applied to converge to the objects' contour edges simultaneously in the two CCD images to perform the stereo matching. Finally, the multiple spatial contours are reconstructed using the cubic B-spline curve interpolation. The true contour length of every spatial contour is computed as the true boundary perimeter of every 3D object. An experiment on the bent surface's perimeter measurement for the four 3D objects indicates that this scheme's measurement repetition error decreases to 0.7 mm.

  17. [Use of liquid crystal eyeglasses for examination and recovery of binocular vision].

    Science.gov (United States)

    Grigorian, A Iu; Avetisov, E S; Kashchenko, T P; Iachmeneva, E I

    1999-01-01

    A new method for diploptic treatment of strabismus is proposed, based on phase division of visual fields using liquid crystal eyeglasses --computer complex. The method is based on stereovision training (allowing stereothreshold measurements up to 150 ang. sec.). The method was tried in examinations of two groups of children: 10 controls and 74 patients with strabismus. Examinations of normal controls gave new criteria for measuring fusion reserves and stereovisual acuity by the proposed method. The therapeutic method was tried in 2 groups of patients. Time course of visual function improvement was followed up by several criteria: changes in binocular status by the color test and improvement of in-depth and stereoscopic visual acuity. The method is recommended for practice. The authors discuss the problem of small angle strabismus.

  18. Intrastromal corneal tattooing as treatment in a case of intractable strabismic diplopia (double binocular vision).

    Science.gov (United States)

    Laria, Carlos; Alió, Jorge L; Piñero, David N

    2010-01-01

    We present the case of a 29 man complaining of intractable diplopia during the last 5 years. He had undergone several surgical procedures for the treatment of his infantile strabismus since age 6 years. After surgery, the patient had been treated on 4 occasions with Botox. He also performed antisuppression exercises to encourage binocular vision. On our examination, the patient showed a 20/20 visual acuity in both eyes and a strabismic dysfunction with slight alphabet pattern, which induced a disturbing constant diplopia. Several treatment options were considered as occlusion therapy or cosmetic contact lenses, but they were not used because they were not acceptable esthetically or not tolerated. Finally, an optical penalization was induced by means of a black corneal tattooing placed at the centre of the cornea. The patient was followed for a period of 18 months, showing a complete elimination of diploia with esthetical acceptance and no inflammatory signs.

  19. Adoption and Sibling Rivalry

    Science.gov (United States)

    ... that can sometimes create conflict, anger, and hurt feelings. Remember, all children will find reasons to argue. Each child in your family should understand her own origins, and those of her brothers and sisters. But ...

  20. Enduring Strategic Rivalries

    Science.gov (United States)

    2014-08-01

    age, were known to be friends, which carried into Richard’s reign when, following the fall of Jerusalem to Saladin in 1187, they joined in the Third...recapture Jerusalem against such a formidable general as Saladin . He returned to Europe in September 1192. In the meantime, Philip had taken advantage of...sading states came under pressure from the forces of Saladin in the late twelfth century, however, the princes were impelled to honour, if not to

  1. Cooperation or Silent Rivalry?

    DEFF Research Database (Denmark)

    Zank, Wolfgang

    2010-01-01

    a gravitational pull which goes beyond economic problems. Furthermore, the EU has gradually built up a coherent policy on many fields. The EU has become the “reform anchor” and most important cooperation partner for Egypt. The progress towards increasing Egypt’s “Stake in the Internal Market” places cooperation...... on an increasingly institutionalized basis. In terms of military cooperation the US is still the partner for Egypt. But outside the military sphere institutionalized cooperation is comparatively week. In particular the failure of the US to conclude a free-trade agreement has been crucial. But it would be wrong...

  2. Prevalence of Accommodative and Non-Strabismic Binocular Anomalies in a Puerto Rican Pediatric Population

    Directory of Open Access Journals (Sweden)

    Stefania M. Paniccia, OD, MS

    2015-06-01

    Full Text Available Background: There exists a considerable void in the literature of studies that examine the prevalence of non-strabismic binocular and accommodative disorders in the pediatric population of Puerto Rico. The purpose of this retrospective study was to fill this void by performing a comprehensive record review of the pediatric clinical population of the InterAmerican University College of Optometry satellite clinics. Methods: This study was performed using a random selection of 593 existing health records of patients between the ages of 5 and 20 years. Patients had participated in a complete optometric assessment between the years 2004 and 2012. The criteria for selection were the absence of strabismus, amblyopia, nystagmus, vertical deviation, corneal pathology, retinal pathology, lens pathology, or any other parameter outside of population requirements. Results: Statistical analysis was performed using the IBM SPSS program. Results of this study indicate that the most common non-strabismic and accommodative anomalies in the studied population are accommodative insufficiency (39.0%, convergence insufficiency (12.6%, convergence excess (9.1%, and accommodative infacility (7.6%. Conclusions: Accommodative and non-strabismic binocular vision problems are prevalent in the pediatric population of the InterAmerican satellite clinics. This is the first epidemiologic study about the prevalence of these conditions in Puerto Rico. Due to the possibility of these non-strabismic and accommodative anomalies resulting in a reduced quality of life for children and affecting school performance, sports performance, and play activities, an appropriate vision evaluation, diagnosis, and treatment is important. Lastly, further comprehensive studies should be conducted in Puerto Rico using this study as a base for data collection and analysis.

  3. Binocular glaucomatous visual field loss and its impact on visual exploration--a supermarket study.

    Science.gov (United States)

    Sippel, Katrin; Kasneci, Enkelejda; Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

    2014-01-01

    Advanced glaucomatous visual field loss may critically interfere with quality of life. The purpose of this study was to (i) assess the impact of binocular glaucomatous visual field loss on a supermarket search task as an example of everyday living activities, (ii) to identify factors influencing the performance, and (iii) to investigate the related compensatory mechanisms. Ten patients with binocular glaucoma (GP), and ten healthy-sighted control subjects (GC) were asked to collect twenty different products chosen randomly in two supermarket racks as quickly as possible. The task performance was rated as "passed" or "failed" with regard to the time per correctly collected item. Based on the performance of control subjects, the threshold value for failing the task was defined as μ+3σ (in seconds per correctly collected item). Eye movements were recorded by means of a mobile eye tracker. Eight out of ten patients with glaucoma and all control subjects passed the task. Patients who failed the task needed significantly longer time (111.47 s ±12.12 s) to complete the task than patients who passed (64.45 s ±13.36 s, t-test, p visual field defect (VFD) area than patients who failed (t-test, p visual field display on average longer search times in a naturalistic supermarket task. However, a considerable number of patients, who compensate by frequent glancing towards the VFD, showed successful task performance. Therefore, systematic exploration of the VFD area seems to be a "time-effective" compensatory mechanism during the present supermarket task.

  4. [Features of the electronic eikonometer for the study of binocular function].

    Science.gov (United States)

    Bourdy, C

    2013-05-01

    After presenting the components of this electronic eikonometer (device schematic and organizational chart) for the analysis and measurement of perceptive effects of binocular disparity, we review the specifics (tests with incorporated magnifications seen in polarized light) and the advantages of this device as compared to existing eikonometers (absence of any intermediary optical system). We provide a list of available tests in the test library and their parametric characteristics: Ogle Spatial Test for Aniseikonia, Fixation Disparity Test: binocular nonius, and Linear and Random stereoscopic tests. We develop a methodology adapted to each type of test and the manipulations to be performed by the operators and observers. We then provide some results of examinations performed with this eikonometer for a sample of observers equipped with glasses, contact lenses or implants. We propose an analysis of these various perceptive effects from experimental and theoretical studies: association between Depth, Disparity and Fusion; brief review of theoretical studies by automatic matrix calculus of retinal image size for various types of eyes: emmetropic and isometropic eyes based on various dioptric elements from Gullstrand's eye, axial anisometropia, anisometropia of conformation, aphakia resulting from these various eyes. We demonstrate the role of these studies in the analysis of subjective measurements of aniseikonia and for the choice of best correction: variations in amplitude and sign of the monocular components of the fixation disparity as a function of the viewing distance, Complexity of depth perception, according to the test used. Considering the evolution of the technology used for the realization of this prototype, we propose that this eikonometer be updated, in particular by using high-resolution flat screens, which would allow improvement and enrichment of the test library (definition, contrast and size of the observed images).

  5. General stereoscopic distortion rectification due to arbitrary viewer motion in binocular stereoscopic display

    Science.gov (United States)

    Li, Qun; Schonfeld, Dan

    2014-03-01

    Background: In binocular stereoscopic display, stereoscopic distortions due to viewer motion, such as depth distortion, shear distortion, and rotation distortion, result in misperception of the stereo content and reduce visual comfort dramat­ ically. In the past, perceived depth distortion has been thoroughly addressed, and shear distortion has been investigated within the context of multi-view display to accommodate motion parallax. However, the impact of rotation distortion has barely been studied. Therefore, no technique is available to address stereoscopic distortions due to general viewer motion. Objective: To preserve an undistorted 3D perception from a fixed viewpoint irrespective of viewing position. Method: We propose a unified system and method that rectifies stereoscopic distortion due to general affine viewer motion and delivers a fixed perspective of the 3D scene without distortion irrespective of viewer motion. The system assumes eye tracking of the viewer and pixel-wisely adjusts the display location of the stereo pair based on tracked viewer eye location. Results: For demonstration purpose, we implement our method on controlling perceived depth in binocular stereoscopic display of red and cyan anaglyph 3D. The user first perceives the designed perspective of the 3D scene at the reference position. The user then moves to 6 different positions with various distances and angles relative to the screen. At all positions, the users report to perceive a much more consistent stereo content with the adjusted displays and at the same time, experience improved visual comfort. Novelty: We address stereoscopic distortions with a goal to maintain a fixed perspective of the stereo scene, and propose a unified solution that simultaneously rectifies the stereoscopic distortions resulted from arbitrary viewer motion.

  6. Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury

    DEFF Research Database (Denmark)

    Schow, Trine; Teasdale, Thomas William; Arendt Rasmussen, Morten

    2016-01-01

    Trine Schow, Thomas William Teasdale and Morten Arendt Rasmussen Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury. SOJ Psychology (in Press)......Trine Schow, Thomas William Teasdale and Morten Arendt Rasmussen Validation of the Vertical Heterophoria Symptom Questionnaire (VHS-Q) In Patients with Balance Problems and Binocular Visual Dysfunction after Acquired Brain Injury. SOJ Psychology (in Press)...

  7. Ultra-deep Large Binocular Camera U-band Imaging of the GOODS-North Field: Depth vs. Resolution

    Science.gov (United States)

    Ashcraft, Teresa; Windhorst, Rogier A.; Jansen, Rolf A.; Cohen, Seth H.; Grazian, Andrea; Boutsia, Konstantina; Fontana, Adriano; Giallongo, Emanuele; O'Connell, Robert W.; Paris, Diego; Rutkowski, Michael J.; Scarlata, Claudia; Testa, Vincenzo

    2017-01-01

    We present a study of the trade-off between depth and resolution using a large number of U-band images in the GOODS-North field obtained with the Large Binocular Camera (LBC) on the Large Binocular Telescope (LBT). Having acquired over 30 hours of total exposure time (315 images, each 5-6 min), we generated multiple image mosaics, starting with the subset of images with the best (FWHM light-profiles to SB ~ 32 mag arcsec-2. This helps constrain how much flux can be missed in galaxy outskirts, which is important for studies of Extragalactic Background Light.In the future, we will expand our analysis of the GOODS-N field to ~26 hours of LBT/LBC R-band surface photometry to similar depths.

  8. Capturing age-related changes in functional contrast sensitivity with decreasing light levels in monocular and binocular vision

    OpenAIRE

    Gillespie-Gallery, H.; Konstantakopoulou, E.; HARLOW, J.A.; Barbur, J. L.

    2013-01-01

    Purpose: It is challenging to separate the effects of normal aging of the retina and visual pathways independently from optical factors, decreased retinal illuminance and early stage disease. This study determined limits to describe the effect of light level on normal, age-related changes in monocular and binocular functional contrast sensitivity. Methods: 95 participants aged 20 to 85 were recruited. Contrast thresholds for correct orientation discrimination of the gap in a Landolt C opt...

  9. Visual cortex and auditory cortex activation in early binocularly blind macaques: A BOLD-fMRI study using auditory stimuli.

    Science.gov (United States)

    Wang, Rong; Wu, Lingjie; Tang, Zuohua; Sun, Xinghuai; Feng, Xiaoyuan; Tang, Weijun; Qian, Wen; Wang, Jie; Jin, Lixin; Zhong, Yufeng; Xiao, Zebin

    2017-04-15

    Cross-modal plasticity within the visual and auditory cortices of early binocularly blind macaques is not well studied. In this study, four healthy neonatal macaques were assigned to group A (control group) or group B (binocularly blind group). Sixteen months later, blood oxygenation level-dependent functional imaging (BOLD-fMRI) was conducted to examine the activation in the visual and auditory cortices of each macaque while being tested using pure tones as auditory stimuli. The changes in the BOLD response in the visual and auditory cortices of all macaques were compared with immunofluorescence staining findings. Compared with group A, greater BOLD activity was observed in the bilateral visual cortices of group B, and this effect was particularly obvious in the right visual cortex. In addition, more activated volumes were found in the bilateral auditory cortices of group B than of group A, especially in the right auditory cortex. These findings were consistent with the fact that there were more c-Fos-positive cells in the bilateral visual and auditory cortices of group B compared with group A (p visual cortices of binocularly blind macaques can be reorganized to process auditory stimuli after visual deprivation, and this effect is more obvious in the right than the left visual cortex. These results indicate the establishment of cross-modal plasticity within the visual and auditory cortices.

  10. Precision calibration method for binocular vision measurement systems based on arbitrary translations and 3D-connection information

    Science.gov (United States)

    Yang, Jinghao; Jia, Zhenyuan; Liu, Wei; Fan, Chaonan; Xu, Pengtao; Wang, Fuji; Liu, Yang

    2016-10-01

    Binocular vision systems play an important role in computer vision, and high-precision system calibration is a necessary and indispensable process. In this paper, an improved calibration method for binocular stereo vision measurement systems based on arbitrary translations and 3D-connection information is proposed. First, a new method for calibrating the intrinsic parameters of binocular vision system based on two translations with an arbitrary angle difference is presented, which reduces the effect of the deviation of the motion actuator on calibration accuracy. This method is simpler and more accurate than existing active-vision calibration methods and can provide a better initial value for the determination of extrinsic parameters. Second, a 3D-connection calibration and optimization method is developed that links the information of the calibration target in different positions, further improving the accuracy of the system calibration. Calibration experiments show that the calibration error can be reduced to 0.09%, outperforming traditional methods for the experiments of this study.

  11. The reproducibility of binocular pattern reversal visual evoked potentials: a single subject design.

    Science.gov (United States)

    Mellow, Tessa B; Liasis, Alki; Lyons, Ruth; Thompson, Dorothy A

    2011-06-01

    This study aimed to investigate the within-participant variability over time of both amplitude and peak latency measures of pattern reversal visual evoked potentials (pVEPs). As a large number of factors are known to contribute to the variability of the pVEPs (such as fixation instability and drowsiness), testing was conducted in controlled conditions with two co-operative participants. PVEPs were recorded during 24 sessions, over an eight-week period using the same equipment and recording settings. The participants viewed a plasma monitor binocularly from a distance of 1 meter. High contrast (97%), black and white checks of side subtense 50', 25', and 12.5' pattern reversed 3/s in a 28 degree test field. The different sized checks were presented in a pseudo-random order. Three runs, each of 100 trials, were acquired to each stimulus from an active electrode placed at Oz referred to aFz. The amplitude of N80-P100 and the latency of P100 were measured. P100 amplitude and latency were stable across sessions and did not depend upon the order of check size presentation. As expected, variation in amplitude was greater than peak latency. The coefficients of variation for different check sizes and participants were 9-14% for pVEP amplitude, but only 1-2% for P100 latency.

  12. Nulling Data Reduction and On-Sky Performance of the Large Binocular Telescope Interferometer

    CERN Document Server

    Defrère, D; Mennesson, B; Hoffmann, W F; Millan-Gabet, R; Skemer, A J; Bailey, V; Danchi, W C; Downey, E C; Durney, O; Grenz, P; Hill, J M; McMahon, T J; Montoya, M; Spalding, E; Vaz, A; Absil, O; Arbo, P; Bailey, H; Brusa, G; Bryden, G; Esposito, S; Gaspar, A; Haniff, C A; Kennedy, G M; Leisenring, J M; Marion, L; Nowak, M; Pinna, E; Powell, K; Puglisi, A; Rieke, G; Roberge, A; Serabyn, E; Sosa, R; Stapeldfeldt, K; Su, K; Weinberger, A J; Wyatt, M C

    2016-01-01

    The Large Binocular Telescope Interferometer (LBTI) is a versatile instrument designed for high-angular resolution and high-contrast infrared imaging (1.5-13 microns). In this paper, we focus on the mid-infrared (8-13 microns) nulling mode and present its theory of operation, data reduction, and on-sky performance as of the end of the commissioning phase in March 2015. With an interferometric baseline of 14.4 meters, the LBTI nuller is specifically tuned to resolve the habitable zone of nearby main-sequence stars, where warm exozodiacal dust emission peaks. Measuring the exozodi luminosity function of nearby main-sequence stars is a key milestone to prepare for future exoEarth direct imaging instruments. Thanks to recent progress in wavefront control and phase stabilization, as well as in data reduction techniques, the LBTI demonstrated in February 2015 a calibrated null accuracy of 0.05% over a three-hour long observing sequence on the bright nearby A3V star beta Leo. This is equivalent to an exozodiacal dis...

  13. Binocular visual tracking and grasping of a moving object with a 3D trajectory predictor

    Directory of Open Access Journals (Sweden)

    J. Fuentes‐Pacheco

    2009-12-01

    Full Text Available This paper presents a binocular eye‐to‐hand visual servoing system that is able to track and grasp a moving object in real time.Linear predictors are employed to estimate the object trajectory in three dimensions and are capable of predicting futurepositions even if the object is temporarily occluded. For its development we have used a CRS T475 manipulator robot with sixdegrees of freedom and two fixed cameras in a stereo pair configuration. The system has a client‐server architecture and iscomposed of two main parts: the vision system and the control system. The vision system uses color detection to extract theobject from the background and a tracking technique based on search windows and object moments. The control system usesthe RobWork library to generate the movement instructions and to send them to a C550 controller by means of the serial port.Experimental results are presented to verify the validity and the efficacy of the proposed visual servoing system.

  14. PEPSI: The high-resolution echelle spectrograph and polarimeter for the Large Binocular Telescope

    CERN Document Server

    Strassmeier, K G; Järvinen, A; Weber, M; Woche, M; Barnes, S I; Bauer, S -M; Beckert, E; Bittner, W; Bredthauer, R; Carroll, T A; Denker, C; Dionies, F; DiVarano, I; Döscher, D; Fechner, T; Feuerstein, D; Granzer, T; Hahn, T; Harnisch, G; Hofmann, A; Lesser, M; Paschke, J; Pankratow, S; Plank, V; Plüschke, D; Popow, E; Sablowski, D; Storm, J

    2015-01-01

    PEPSI is the bench-mounted, two-arm, fibre-fed and stabilized Potsdam Echelle Polarimetric and Spectroscopic Instrument for the 2x8.4 m Large Binocular Telescope (LBT). Three spectral resolutions of either 43 000, 120 000 or 270 000 can cover the entire optical/red wavelength range from 383 to 907 nm in three exposures. Two 10.3kx10.3k CCDs with 9-{\\mu}m pixels and peak quantum efficiencies of 96 % record a total of 92 echelle orders. We introduce a new variant of a wave-guide image slicer with 3, 5, and 7 slices and peak efficiencies between 96 %. A total of six cross dispersers cover the six wavelength settings of the spectrograph, two of them always simultaneously. These are made of a VPH-grating sandwiched by two prisms. The peak efficiency of the system, including the telescope, is 15% at 650 nm, and still 11% and 10% at 390 nm and 900 nm, respectively. In combination with the 110 m2 light-collecting capability of the LBT, we expect a limiting magnitude of 20th mag in V in the low-resolution mode. The R=...

  15. iLocater: a diffraction-limited Doppler spectrometer for the Large Binocular Telescope

    Science.gov (United States)

    Crepp, Justin R.; Crass, Jonathan; King, David; Bechter, Andrew; Bechter, Eric; Ketterer, Ryan; Reynolds, Robert; Hinz, Philip; Kopon, Derek; Cavalieri, David; Fantano, Louis; Koca, Corina; Onuma, Eleanya; Stapelfeldt, Karl; Thomes, Joseph; Wall, Sheila; Macenka, Steven; McGuire, James; Korniski, Ronald; Zugby, Leonard; Eisner, Joshua; Gaudi, B. S.; Hearty, Fred; Kratter, Kaitlin; Kuchner, Marc; Micela, Giusi; Nelson, Matthew; Pagano, Isabella; Quirrenbach, Andreas; Schwab, Christian; Skrutskie, Michael; Sozzetti, Alessandro; Woodward, Charles; Zhao, Bo

    2016-08-01

    We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 μm), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R 150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of low-mass planets using the Doppler technique, iLocater will also advance areas of research that involve crowded fields, line-blanketing, and weak absorption lines.

  16. iLocater: A Diffraction-limited Doppler Spectrometer for the Large Binocular Telescope

    CERN Document Server

    Crepp, Justin R; King, David; Bechter, Andrew; Bechter, Eric; Ketterer, Ryan; Reynolds, Robert; Hinz, Philip; Kopon, Derek; Cavalieri, David; Fantano, Louis; Koca, Corina; Onuma, Eleanya; Stapelfeldt, Karl; Thomes, Joseph; Wall, Sheila; Macenka, Steven; McGuire, James; Korniski, Ronald; Zugby, Leonard; Eisner, Joshua; Gaudi, B Scott; Hearty, Fred; Kratter, Kaitlin; Kuchner, Marc; Micela, Giusi; Nelson, Matthew; Pagano, Isabella; Quirrenbach, Andreas; Schwab, Christian; Skrutskie, Michael; Sozzetti, Alessandro; Woodward, Charles E; Zhao, Bo

    2016-01-01

    We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands (0.97-1.30 microns), a fiber-injection acquisition camera system, and a wavelength calibration unit. iLocater will deliver high spectral resolution (R~150,000-240,000) measurements that permit novel studies of stellar and substellar objects in the solar neighborhood including extrasolar planets. Unlike previous planet-finding instruments, which are seeing-limited, iLocater operates at the diffraction limit and uses single mode fibers to eliminate the effects of modal noise entirely. By receiving starlight from two 8.4m diameter telescopes that each use "extreme" adaptive optics (AO), iLocater shows promise to overcome the limitations that prevent existing instruments from generating sub-meter-per-second radial velocity (RV) precision. Although optimized for the characterization of ...

  17. A wearable infrared video pupillography with multi-stimulation of consistent illumination for binocular pupil response

    Science.gov (United States)

    Mang, Ou-Yang; Ko, Mei Lan; Tsai, Yi-Chun; Chiou, Jin-Chern; Huang, Ting-Wei

    2016-03-01

    The pupil response to light can reflect various kinds of diseases which are related to physiological health. Pupillary abnormalities may be influenced on people by autonomic neuropathy, glaucoma, diabetes, genetic diseases, and high myopia. In the early stage of neuropathy, it is often asymptomatic and difficulty detectable by ophthalmologists. In addition, the position of injured nerve can lead to unsynchronized pupil response for human eyes. In our study, we design the pupilometer to measure the binocular pupil response simultaneously. It uses the different wavelength of LEDs such as white, red, green and blue light to stimulate the pupil and record the process. Therefore, the pupilometer mainly contains two systems. One is the image acquisition system, it use the two cameras modules with the same external triggered signal to capture the images of the pupil simultaneously. The other one is the illumination system. It use the boost converter ICs and LED driver ICs to supply the constant current for LED to maintain the consistent luminance in each experiments for reduced experimental error. Furthermore, the four infrared LEDs are arranged nearby the stimulating LEDs to illuminate eyes and increase contrast of image for image processing. In our design, we success to implement the function of synchronized image acquisition with the sample speed in 30 fps and the stable illumination system for precise measurement of experiment.

  18. Binocular videogrammetric system for three-dimensional measurement in low-speed wind tunnel

    Science.gov (United States)

    Zhu, Ye; Gu, Yonggang; Zhai, Chao

    2014-11-01

    In order to avoid the defects of contact measurement, such as limited range, complex constructing and disability of 3-D parameter acquisition, we built a binocular videogrammetric system for measuring 3-D geometry parameters of wind tunnel test models, for instance, displacement, rotation angle and vibration, in low-speed wind tunnel. The system is based on the principles of close-range digital photogrammetry. As a non-contact system, it acquires parameters without interference in the experiments, and it has adjustable range and simple structure. It is worth mentioning that this is a Realtime measurement system, so that it can greatly compress the experiment period, furthermore, it is also able to provide some specific experiments with parameters for online adjustment. In this system, images are acquired through two industrial digital cameras and a PCI-E image acquisition card, and they are processed in a PC. The two cameras are triggered by signals come from a function signal generator, so that images of different cameras will have good temporal synchronization to ensure the accuracy of 3-D reconstruction. A two-step stereo calibration technique using planar pattern developed by Zhengyou Zhang is used to calibrate these cameras. Results of wind tunnel test indicate that the system can provide displacement accuracy better than 0.1% and rotation angle accuracy better than 0.1 degree, besides, the vibration frequency accuracy is superior to 0.1Hz in the low-frequency range.

  19. Structural Parameters Calibration for Binocular Stereo Vision Sensors Using a Double-Sphere Target

    Directory of Open Access Journals (Sweden)

    Zhenzhong Wei

    2016-07-01

    Full Text Available Structural parameter calibration for the binocular stereo vision sensor (BSVS is an important guarantee for high-precision measurements. We propose a method to calibrate the structural parameters of BSVS based on a double-sphere target. The target, consisting of two identical spheres with a known fixed distance, is freely placed in different positions and orientations. Any three non-collinear sphere centres determine a spatial plane whose normal vector under the two camera-coordinate-frames is obtained by means of an intermediate parallel plane calculated by the image points of sphere centres and the depth-scale factors. Hence, the rotation matrix R is solved. The translation vector T is determined using a linear method derived from the epipolar geometry. Furthermore, R and T are refined by nonlinear optimization. We also provide theoretical analysis on the error propagation related to the positional deviation of the sphere image and an approach to mitigate its effect. Computer simulations are conducted to test the performance of the proposed method with respect to the image noise level, target placement times and the depth-scale factor. Experimental results on real data show that the accuracy of measurement is higher than 0.9‰, with a distance of 800 mm and a view field of 250 × 200 mm2.

  20. Investigating binocular summation in human vision using complementary fused external noise

    Science.gov (United States)

    Howell, Christopher L.; Olson, Jeffrey T.

    2016-05-01

    The impact noise has on the processing of visual information at various stages within the human visual system (HVS) is still an open research area. To gain additional insight, twelve experiments were administered to human observers using sine wave targets to determine their contrast thresholds. A single frame of additive white Gaussian noise (AWGN) and its complement were used to investigate the effect of noise on the summation of visual information within the HVS. A standard contrast threshold experiment served as the baseline for comparisons. In the standard experiment, a range of sine wave targets are shown to the observers and their ability to detect the targets at varying contrast levels were recorded. The remaining experiments added some form of noise (noise image or its complement) and/or an additional sine wave target separated between one to three octaves to the test target. All of these experiments were tested using either a single monitor for viewing the targets or with a dual monitor presentation method for comparison. In the dual monitor experiments, a ninety degree mirror was used to direct each target to a different eye, allowing for the information to be fused binocularly. The experiments in this study present different approaches for delivering external noise to the HVS, and should allow for an improved understanding regarding how noise enters the HVS and what impact noise has on the processing of visual information.

  1. Large Binocular Telescope Adaptive Optics System: New achievements and perspectives in adaptive optics

    CERN Document Server

    Esposito, Simone; Pinna, Enrico; Puglisi, Alfio; Quirós-Pacheco, Fernando; Arcidiacono, Carmelo; Xompero, Marco; Briguglio, Runa; Agapito, Guido; Busoni, Lorenzo; Fini, Luca; Argomedo, Javier; Gherardi, Alessandro; Brusa, Guido; Miller, Douglas; Guerra, Juan Carlos; Stefanini, Paolo; Salinari, Piero; 10.1117/12.898641

    2012-01-01

    The Large Binocular Telescope (LBT) is a unique telescope featuring two co-mounted optical trains with 8.4m primary mirrors. The telescope Adaptive Optics (AO) system uses two innovative key components, namely an adaptive secondary mirror with 672 actuators and a high-order pyramid wave-front sensor. During the on-sky commissioning such a system reached performances never achieved before on large ground-based optical telescopes. Images with 40mas resolution and Strehl Ratios higher than 80% have been acquired in H band (1.6 micron). Such images showed a contrast as high as 10e-4. Based on these results, we compare the performances offered by a Natural Guide Star (NGS) system upgraded with the state-of-the-art technology and those delivered by existing Laser Guide Star (LGS) systems. The comparison, in terms of sky coverage and performances, suggests rethinking the current role ascribed to NGS and LGS in the next generation of AO systems for the 8-10 meter class telescopes and Extremely Large Telescopes (ELTs)...

  2. Large Binocular Telescope Interferometer Adaptive Optics: On-sky performance and lessons learned

    CERN Document Server

    Bailey, Vanessa P; Puglisi, Alfio T; Esposito, Simone; Vaitheeswaran, Vidhya; Skemer, Andrew J; Defrere, Denis; Vaz, Amali; Leisenring, Jarron M

    2014-01-01

    The Large Binocular Telescope Interferometer is a high contrast imager and interferometer that sits at the combined bent Gregorian focus of the LBT's dual 8.4~m apertures. The interferometric science drivers dictate 0.1'' resolution with $10^3-10^4$ contrast at $10~\\mu m$, while the $4~\\mu m$ imaging science drivers require even greater contrasts, but at scales $>$0.2''. In imaging mode, LBTI's Adaptive Optics system is already delivering $4~\\mu m$ contrast of $10^4-10^5$ at $0.3''-0.75''$ in good conditions. Even in poor seeing, it can deliver up to 90\\% Strehl Ratio at this wavelength. However, the performance could be further improved by mitigating Non-Common Path Aberrations. Any NCPA remedy must be feasible using only the current hardware: the science camera, the wavefront sensor, and the adaptive secondary mirror. In preliminary testing, we have implemented an ``eye doctor'' grid search approach for astigmatism and trefoil, achieving 5\\% improvement in Strehl Ratio at $4~\\mu m$, with future plans to tes...

  3. Noncontact binocular eye-gaze tracking for point-of-gaze estimation in three dimensions.

    Science.gov (United States)

    Hennessey, Craig; Lawrence, Peter

    2009-03-01

    Binocular eye-gaze tracking can be used to estimate the point-of-gaze (POG) of a subject in real-world 3-D space using the vergence of the eyes. In this paper, a novel noncontact model-based technique for 3-D POG estimation is presented. The noncontact system allows people to select real-world objects in 3-D physical space using their eyes, without the need for head-mounted equipment. Remote 3-D POG estimation may be especially useful for persons with quadriplegia or Amyotrophic Lateral Sclerosis. It would also enable a user to select 3-D points in space generated by 3-D volumetric displays, with potential applications to medical imaging and telesurgery. Using a model-based POG estimation algorithm allows for free head motion and a single stage of calibration. It is shown that an average accuracy of 3.93 cm was achieved over a workspace volume of 30 x 23 x 25 cm (W x H x D) with a maximum latency of 1.5 s due to the digital filtering employed. The users were free to naturally move and reorient their heads while operating the system, within an allowable headspace of 3 cm x 9 cm x 14 cm.

  4. Quantifying interactions between accommodation and vergence in a binocularly normal population.

    Science.gov (United States)

    Sweeney, Laura E; Seidel, Dirk; Day, Mhairi; Gray, Lyle S

    2014-12-01

    Stimulation of the accommodation system results in a response in the vergence system via accommodative vergence cross-link interactions, and stimulation of the vergence system results in an accommodation response via vergence accommodation cross-link interactions. Cross-link interactions are necessary in order to ensure simultaneous responses in the accommodation and vergence systems. The crosslink interactions are represented most comprehensively by the response AC/A (accommodative vergence) and CA/C (vergence accommodation) ratios, although the stimulus AC/A ratio is measured clinically, and the stimulus CA/C ratio is seldom measured in clinical practice. The present study aims to quantify both stimulus and response AC/A and CA/C ratios in a binocularly normal population, and determine the relationship between them. 25 Subjects (mean ± SD age 21.0 ± 1.9 years) were recruited from the university population. A significant linear relationship was found between the stimulus and response ratios, for both AC/A (r² = 0.96, p values, and lower than response ratios at high values (95% CI -0.46 to 0.42 D/MA). Agreement between stimulus and response CA/C ratios is poorer than that found for AC/A ratios due to increased variability in vergence responses when viewing the Gaussian blurred target. This study has shown that more work is needed to refine the methodology of CA/C ratio measurement.

  5. Binocular robot vision emulating disparity computation in the primary visual cortex.

    Science.gov (United States)

    Shimonomura, Kazuhiro; Kushima, Takayuki; Yagi, Tetsuya

    2008-01-01

    We designed a VLSI binocular vision system that emulates the disparity computation in the primary visual cortex (V1). The system consists of two silicon retinas, orientation chips, and field programmable gate array (FPGA), mimicking a hierarchical architecture of visual information processing in the disparity energy model. The silicon retinas emulate a Laplacian-Gaussian-like receptive field of the vertebrate retina. The orientation chips generate an orientation-selective receptive field by aggregating multiple pixels of the silicon retina, mimicking the Hubel-Wiesel-type feed-forward model in order to emulate a Gabor-like receptive field of simple cells. The FPGA receives outputs from the orientation chips corresponding to the left and right eyes and calculates the responses of the complex cells based on the disparity energy model. The system can provide the responses of complex cells tuned to five different disparities and a disparity map obtained by comparing these energy outputs. Owing to the combination of spatial filtering by analog parallel circuits and pixel-wise computation by hard-wired digital circuits, the present system can execute the disparity computation in real time using compact hardware.

  6. A Real-time Range Finding System with Binocular Stereo Vision

    Directory of Open Access Journals (Sweden)

    Xiao-bo Lai

    2012-05-01

    Full Text Available To acquire range information for mobile robots, a TMS320DM642 DSP‐based range finding system with binocular stereo vision is proposed. Firstly, paired images of the target are captured and a Gaussian filter, as well as improved Sobel kernels, are achieved. Secondly, a feature‐based local stereo matching algorithm is performed so that the space location of the target can be determined. Finally, in order to improve the reliability and robustness of the stereo matching algorithm under complex conditions, the confidence filter and the left‐right consistency filter are investigated to eliminate the mismatching points. In addition, the range finding algorithm is implemented in the DSP/BIOS operating system to gain real‐time control. Experimental results show that the average accuracy of range finding is more than 99% for measuring single‐point distances equal to 120cm in the simple scenario and the algorithm takes about 39ms for ranging a time in a complex scenario. The effectivity, as well as the feasibility, of the proposed range finding system are verified.

  7. High Contrast Imaging in the Visible: First Experimental Results at the Large Binocular Telescope

    CERN Document Server

    Pedichini, F; Ambrosino, A; Puglisi, A; Pinna, E; Bailey, V; Carbonaro, L; Centrone, M; Christou, J; Esposito, S; Farinato, J; Fiore, F; Giallongo, E; Hill, J M; Hinz, P M; Sabatini, L

    2016-01-01

    In February 2014, the SHARK-VIS (System for High contrast And coronography from R to K at VISual bands) Forerunner, a high contrast experimental imager operating at visible wavelengths, was installed at LBT (Large Binocular Telescope). Here we report on the first results obtained by recent on-sky tests. These results show the extremely good performance of the LBT ExAO (Extreme Adaptive Optics) system at visible wavelengths, both in terms of spatial resolution and contrast achieved. Similarly to what was done by (Amara et al. 2012), we used the SHARK-VIS Forerunner data to quantitatively assess the contrast enhancement. This is done by injecting several different synthetic faint objects in the acquired data and applying the ADI (angular differential imaging) technique. A contrast of the order of $5 \\times 10^{-5}$ is obtained at 630 nm for angular separations from the star larger than 100 mas. These results are discussed in light of the future development of SHARK-VIS and compared to those obtained by other hi...

  8. Quality of life in patients with age-related macular degeneration with monocular and binocular legal blindness Qualidade de vida de pacientes com degeneração macular relacionada à idade com cegueira legal monocular e binocular

    Directory of Open Access Journals (Sweden)

    Roberta Ferrari Marback

    2007-01-01

    Full Text Available OBJECTIVE: To evaluate the quality of life for persons affected by age-related macular degeneration that results in monocular or binocular legal blindness. METHODS: An analytic transversal study using the National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25 was performed. Inclusion criteria were persons of both genders, aged more than 50 years old, absence of cataracts, diagnosis of age-related monocular degeneration in at least one eye and the absence of other macular diseases. The control group was paired by sex, age and no ocular disease. RESULTS: Group 1 (monocular legal blindness was composed of 54 patients (72.22% females and 27.78% males, aged 51 to 87 years old, medium age 74.61 ± 7.27 years; group 2 (binocular legal blindness was composed of 54 patients (46.30% females and 53.70% males aged 54 to 87 years old, medium age 75.61 ± 6.34 years. The control group was composed of 40 patients (40% females and 60% males, aged 50 to 81 years old, medium age 65.65 ± 7.56 years. The majority of the scores were statistically significantly higher in group 1 and the control group in relation to group 2 and higher in the control group when compared to group 1. CONCLUSIONS: It was evident that the quality of life of persons with binocular blindness was more limited in relation to persons with monocular blindness. Both groups showed significant impairment in quality of life when compared to normal persons.OBJETIVO: Avaliar a qualidade de vida de portadores de degeneração macular relacionada à idade com cegueira legal monocular e binocular. MÉTODOS: Foi realizado estudo transversal analítico por meio do questionário National Eye Institute Visual Functioning Questionnaire (NEI VFQ-25. Os critérios de inclusão foram: indivíduos de ambos os sexos, idade maior que 50 anos, ausência de catarata, diagnóstico de degeneração macular relacionada à idade avançada em pelo menos um dos olhos, sem outras maculopatias. O Grupo Controle

  9. Current status of the facility instrumentation suite at the Large Binocular Telescope Observatory

    Science.gov (United States)

    Rothberg, Barry; Kuhn, Olga; Edwards, Michelle L.; Hill, John M.; Thompson, David; Veillet, Christian; Wagner, R. Mark

    2016-07-01

    The current status of the facility instrumentation for the Large Binocular Telescope (LBT) is reviewed. The LBT encompasses two 8.4 meter primary mirrors on a single mount yielding an effective collecting area of 11.8 meters or 23 meters when interferometrically combined. The three facility instruments at LBT include: 1) the Large Binocular Cameras (LBCs), each with a 23'× 25' field of view (FOV). The blue optimized and red optimized optical wavelength LBCs are mounted at the prime focus of the SX (left) and DX (right) primary mirrors, respectively. Combined, the filter suite of the two LBCs cover 0.3-1.1 μm, including the addition of new medium-band filters centered on TiO (0.78 μm) and CN (0.82 μm) 2) the Multi-Object Double Spectrograph (MODS), two identical optical spectrographs each mounted at the straight through f/15 Gregorian focus of the primary mirrors. The capabilities of MODS-1 and -2 include imaging with Sloan filters (u, g, r, i, and z) and medium resolution (R ˜ 2000) spectroscopy, each with 24 interchangeable masks (multi-object or longslit) over a 6'× 6' FOV. Each MODS is capable of blue (0.32-0.6 μm) and red (0.5-1.05 μm) wavelength only spectroscopy coverage or both can employ a dichroic for 0.32-1.05 μm wavelength coverage (with reduced coverage from 0.56- 0.57 μm) and 3) the two LBT Utility Camera in the Infrared instruments (LUCIs), are each mounted at a bent-front Gregorian f/15 focus of a primary mirror. LUCI-1 and 2 are designed for seeing-limited (4'× 4' FOV) and active optics using thin-shell adaptive secondary mirrors (0.5'× 0.5' FOV) imaging and spectroscopy over the wavelength range of 0.95-2.5 μm and spectroscopic resolutions of 400 advantage of the active optics SX secondary; and to install a grating designed primarily for use with high resolution active optics. Thus, like MODS-1 and -2, both LUCIs now have specifications nearly identical to each other. The software interface for both LUCIs have also been replaced

  10. iLocater: A Diffraction-Limited Doppler Spectrometer for the Large Binocular Telescope

    Science.gov (United States)

    Crepp, Justin R.; Bechter, A.; Bechter, E.; Berg, M.; Carroll, J.; Collins, K.; Corpuz, T.; Ketterer, R.; Kielb, E.; Stoddard, R.; Eisner, J. A.; Gaudi, B. S.; Hinz, P.; Kratter, K. M.; Macela, G.; Quirrenbach, A.; Skrutskie, M. F.; Sozzetti, A.; Woodward, C. E.; Zhao, B.

    2014-01-01

    We are building an ultra-precise Doppler spectrometer for the Large Binocular Telescope (LBT) that operates at near-infrared wavelengths. The instrument, named iLocater, holds significant advantages over current and forth-coming Doppler designs. An R=110,000 spectrograph that operates in the Y-band, iLocater will receive a well-corrected beam from the LBT “extreme” adaptive optics system and use single-mode optical fibers to stabilize the instrument line spread function. With an input image 30 times smaller than comparable seeing-limited instruments (i.e., all Doppler radial velocity predecessors), iLocater will simultaneously achieve high spectral resolution, high spatial resolution, high throughput, and a compact optical design for low cost (affordable gratings). By working at the diffraction-limit, it is possible to circumvent, or ameliorate, many of the sources of noise common to seeing-limited spectrometers, including background contamination, thermal drifts, binary star interlopers, and pressure-induced changes in refractive index. Further, starlight received simultaneously from the LBT’s two separate telescope dishes may be used to monitor and remove internal systematic RV errors. iLocater will: identify "Earth-like" planets orbiting in the habitable-zone around nearby M-dwarf stars; perform the first systematic study of planet occurrence around binary stars as a function of their orbital separation; obtain the first spin-orbit orientation measurements of transiting terrestrial planets; and acquire essential follow-up observations for NASA's planned Transiting Exoplanet Survey Satellite (TESS) mission. In this poster, we present iLocater's design and science cases.

  11. Binocular Coordination of the Human Vestibulo-Ocular Reflex during Off-axis Pitch Rotation

    Science.gov (United States)

    Wood, S. J.; Reschke, M. F.; Kaufman, G. D.; Black, F. O.; Paloski, W. H.

    2006-01-01

    Head movements in the sagittal pitch plane typically involve off-axis rotation requiring both vertical and horizontal vergence ocular reflexes to compensate for angular and translational motion relative to visual targets of interest. The purpose of this study was to compare passive pitch VOR responses during rotation about an Earth-vertical axis (canal only cues) with off-axis rotation (canal and otolith cues). Methods. Eleven human subjects were oscillated sinusoidally at 0.13, 0.3 and 0.56 Hz while lying left-side down with the interaural axis either aligned with the axis of rotation or offset by 50 cm. In a second set of measurements, twelve subjects were also tested during sinusoidally varying centrifugation over the same frequency range. The modulation of vertical and horizontal vergence ocular responses was measured with a binocular videography system. Results. Off-axis pitch rotation enhanced the vertical VOR at lower frequencies and enhanced the vergence VOR at higher frequencies. During sinusoidally varying centrifugation, the opposite trend was observed for vergence, with both vertical and vergence vestibulo-ocular reflexes being suppressed at the highest frequency. Discussion. These differential effects of off-axis rotation over the 0.13 to 0.56 Hz range are consistent with the hypothesis that otolith-ocular reflexes are segregated in part on the basis of stimulus frequency. At the lower frequencies, tilt otolith-ocular responses compensate for declining canal input. At higher frequencies, translational otolith-ocular reflexes compensate for declining visual contributions to the kinematic demands required for fixating near targets.

  12. Forecasting surface-layer atmospheric parameters at the Large Binocular Telescope site

    Science.gov (United States)

    Turchi, Alessio; Masciadri, Elena; Fini, Luca

    2017-04-01

    In this paper, we quantify the performance of an automated weather forecast system implemented on the Large Binocular Telescope (LBT) site at Mt Graham (Arizona) in forecasting the main atmospheric parameters close to the ground. The system employs a mesoscale non-hydrostatic numerical model (Meso-Nh). To validate the model, we compare the forecasts of wind speed, wind direction, temperature and relative humidity close to the ground with the respective values measured by instrumentation installed on the telescope dome. The study is performed over a large sample of nights uniformly distributed over 2 yr. The quantitative analysis is done using classical statistical operators [bias, root-mean-square error (RMSE) and σ] and contingency tables, which allows us to extract complementary key information, such as the percentage of correct detections (PC) and the probability of obtaining a correct detection within a defined interval of values (POD). The results of our study indicate that the model performance in forecasting the atmospheric parameters we have just cited are very good, in some cases excellent: RMSE for temperature is below 1°C, for relative humidity it is 14 per cent and for the wind speed it is around 2.5 m s-1. The relative error of the RMSE for wind direction varies from 9 to 17 per cent depending on the wind speed conditions. This work is performed in the context of the ALTA (Advanced LBT Turbulence and Atmosphere) Center project, whose final goal is to provide forecasts of all the atmospheric parameters and the optical turbulence to support LBT observations, adaptive optics facilities and interferometric facilities.

  13. Distribution of Binocular Vision Anomalies and Refractive Errors in Iranian Children With Learning Disabilities

    Directory of Open Access Journals (Sweden)

    Yekta

    2015-11-01

    Full Text Available Background Visual problems in children contribute to learning disorders, which are one of the most influential factors in learning. Objectives The aim of the present study was to determine the prevalence of refractive and binocular vision errors in children with learning disorders. Patients and Methods In this cross-sectional study, 406 children with learning disorders with a mean age of 8.56 ± 2.4 years were evaluated. Examinations included the determination of refractive errors with an auto-refractometer and static retinoscopy, measurement of visual acuity with a Snellen chart, evaluation of ocular deviation, and measurement of stereopsis, amplitude of accommodation, and near point of convergence. Results Of the 406 participants, 319 (78.6% were emmetropic in the right eye, 14.5% had myopia, and 6.9% had hyperopia according to cycloplegic refraction. Astigmatism was detected in 75 (18.5% children. In our study, 89.9% of the children had no deviation, 1.0% had esophoria, and 6.4% had exophoria . In addition, 2.2% of the children had suppression. The near point of convergence ranged from 3 to 18 cm, with a mean of 10.12 ± 3.274 cm. Moreover, 98.5 and 98.0% of the participants achieved complete vision with the best correction in the right and left eye, respectively. The best corrected visual acuity in the right and left eye was achieved in 98.5 and 98.0% of the children, respectively. Conclusions The pattern of visual impairment in learning-impaired children is not much different from that in normal children; however, because these children may not be able to express themselves clearly, lack of correct diagnosis and appropriate treatment has resulted in a marked defect in recognizing visual disorders in these children. Therefore, gaining knowledge of the prevalence of refractive errors in children with learning disorders can be considered the first step in their treatment.

  14. High-precision method of binocular camera calibration with a distortion model.

    Science.gov (United States)

    Li, Weimin; Shan, Siyu; Liu, Hui

    2017-03-10

    A high-precision camera calibration method for binocular stereo vision system based on a multi-view template and alternative bundle adjustment is presented in this paper. The proposed method could be achieved by taking several photos on a specially designed calibration template that has diverse encoded points in different orientations. In this paper, the method utilized the existing algorithm used for monocular camera calibration to obtain the initialization, which involves a camera model, including radial lens distortion and tangential distortion. We created a reference coordinate system based on the left camera coordinate to optimize the intrinsic parameters of left camera through alternative bundle adjustment to obtain optimal values. Then, optimal intrinsic parameters of the right camera can be obtained through alternative bundle adjustment when we create a reference coordinate system based on the right camera coordinate. We also used all intrinsic parameters that were acquired to optimize extrinsic parameters. Thus, the optimal lens distortion parameters and intrinsic and extrinsic parameters were obtained. Synthetic and real data were used to test the method. The simulation results demonstrate that the maximum mean absolute relative calibration errors are about 3.5e-6 and 1.2e-6 for the focal length and the principal point, respectively, under zero-mean Gaussian noise with 0.05 pixels standard deviation. The real result shows that the reprojection error of our model is about 0.045 pixels with the relative standard deviation of 1.0e-6 over the intrinsic parameters. The proposed method is convenient, cost-efficient, highly precise, and simple to carry out.

  15. Metabolic changes in the visual cortex of binocular blindness macaque monkeys: a proton magnetic resonance spectroscopy study.

    Directory of Open Access Journals (Sweden)

    Lingjie Wu

    Full Text Available PURPOSE: To evaluate proton magnetic resonance spectroscopy ((1H-MRS in a study of cross-modal plasticity in the visual cortex of binocular blindness macaque monkeys. MATERIALS AND METHODS: Four healthy neonatal macaque monkeys were randomly divided into 2 groups, with 2 in each group. Optic nerve transection was performed in both monkeys in the experimental group (group B to obtain binocular blindness. Two healthy macaque monkeys served as a control group (group A. After sixteen months post-procedure, (1H-MRS was performed in the visual cortex of all monkeys. We compared the peak areas of NAA, Cr, Cho, Glx and Ins and the ratios of NAA/Cr, Cho/Cr, Glx/Cr and Ins/Cr of each monkey in group B with group A. RESULTS: The peak area of NAA and the NAA/Cr ratio in the visual cortex of monkey 4 in group B were found to be dramatically decreased, the peak area of NAA slightly decreased and the NAA/Cr ratio clearly decreased in visual cortex of monkey 3 in group B than those in group A. The peak area of Ins and the Ins/Cr ratio in the visual cortex of monkey 4 in group B slightly increased. The peak area of Cho and the Cho/Cr ratio in the visual cortex of all monkeys in group B dramatically increased compared with group A. The peak area of Glx in the visual cortex of all monkeys in group B slightly increased compared with group A. CONCLUSIONS: (1H-MRS could detect biochemical and metabolic changes in the visual cortex and therefore this technique can be used to provide valuable information for investigating the mechanisms of cross-modal plasticity of binocular blindness in a macaque monkey model.

  16. Near Point of Convergence Break for Different Age Groups in Turkish Population with Normal Binocular Vision: Normative Data

    Directory of Open Access Journals (Sweden)

    Nihat Sayın

    2013-12-01

    Full Text Available Purpose: The purpose of this study was to evaluate the near point of convergence break in Turkish population with normal binocular vision and to obtain the normative data for the near point of convergence break in different age groups. Such database has not been previously reported. Material and Method: In this prospective study, 329 subjects with normal binocular vision (age range, 3-72 years were evaluated. The near point of convergence break was measured 4 times repeatedly with an accommodative target. Mean values of near point of convergence break were provided for these age groups (≤10, 11-20, 21-30, 31-40, 41-50, 51-60, and >60 years old. A statistical comparison (one-way ANOVA and post-hoc test of these values between age groups was performed. A correlation between the near point of convergence break and age was evaluated by Pearson’s correlation test. Results: The mean value for near point of convergence break was 2.46±1.88 (0.5-14 cm. Specifically, 95% of measurements in all subjects were 60 year-old age groups in the near point of convergence break values (p=0.0001, p=0.0001, p=0.006, p=0.001, p= 0.004. A mild positive correlation was observed between the increase in near point of convergence break and increase of age (r=0.355 (p<0.001. Discussion: The values derived from a relatively large study population to establish a normative database for the near point of convergence break in the Turkish population with normal binocular vision are in relevance with age. This database has not been previously reported. (Turk J Ophthalmol 2013; 43: 402-6

  17. Brief monocular deprivation as an assay of short-term visual sensory plasticity in schizophrenia – the binocular effect.

    Directory of Open Access Journals (Sweden)

    John J Foxe

    2013-12-01

    Full Text Available Background: Visual sensory processing deficits are consistently observed in schizophrenia, with clear amplitude reduction of the visual evoked potential (VEP during the initial 50-150 milliseconds of processing. Similar deficits are seen in unaffected first-degree relatives and drug-naïve first-episode patients, pointing to these deficits as potential endophenotypic markers. Schizophrenia is also associated with deficits in neural plasticity, implicating dysfunction of both glutamatergic and gabaergic systems. Here, we sought to understand the intersection of these two domains, asking whether short-term plasticity during early visual processing is specifically affected in schizophrenia. Methods: Brief periods of monocular deprivation induce relatively rapid changes in the amplitude of the early VEP – i.e. short-term plasticity. Twenty patients and twenty non-psychiatric controls participated. VEPs were recorded during binocular viewing, and were compared to the sum of VEP responses during brief monocular viewing periods (i.e. Left-eye + Right-eye viewing. Results: Under monocular conditions, neurotypical controls exhibited an effect that patients failed to demonstrate. That is, the amplitude of the summed monocular VEPs was robustly greater than the amplitude elicited binocularly during the initial sensory processing period. In patients, this binocular effect was absent. Limitations: Patients were all medicated. Ideally, this study would also include first-episode unmedicated patients.Conclusions: These results suggest that short-term compensatory mechanisms that allow healthy individuals to generate robust VEPs in the context of monocular deprivation are not effectively activated in patients with schizophrenia. This simple assay may provide a useful biomarker of short-term plasticity in the psychotic disorders and a target endophenotype for therapeutic interventions.

  18. [The role of rotary prisms and dynamic color stimuli in binocular vision recovery in children with squint].

    Science.gov (United States)

    Seleznev, A V; Vakurin, E A; Kashchenko, T P; Vakurina, A E; Abramova, T F

    2010-01-01

    A modified procedure for diploid treatment is proposed to disinhibit a functional scotoma and to develop binocular vision (BV) in children with squint. The procedure is to examine a special test object through rotary prisms and polaroid filters inserted into a modernized spectacle frame. During treatment there is an opportunity of simultaneously changing the color of the test object and the position of its image on the retina. The study enrolled children in whom previous traditional methods for BV recovery had failed. Treatment using the proposed procedure could recover bifoveal fusion in 88.3% of cases (as evidenced by synoptophore examination) and BY in 73.3% (as shown by scanning haploscopy).

  19. Relação entre sinais e sintomas em pacientes com disfunções da visão binocular, acomodativas e oculomotoras

    OpenAIRE

    Sampaio, Maria de Fátima Teixeira

    2015-01-01

    Dissertação de mestrado em Optometria Avançada Na prática clínica, muitas vezes o profissional se depara com alterações da função acomodativa ou da visão binocular, no entanto, dada a forte relação entre estes dois sistemas, um indivíduo com um problema acomodativo pode apresentar um problema binocular secundário, assim como um indivíduo com um problema binocular pode apresentar uma disfunção acomodativa secundária. Hoje em dia, a maioria da população necessita de um uso fre...

  20. PEPSI: The high-resolution échelle spectrograph and polarimeter for the Large Binocular Telescope

    Science.gov (United States)

    Strassmeier, K. G.; Ilyin, I.; Järvinen, A.; Weber, M.; Woche, M.; Barnes, S. I.; Bauer, S.-M.; Beckert, E.; Bittner, W.; Bredthauer, R.; Carroll, T. A.; Denker, C.; Dionies, F.; DiVarano, I.; Döscher, D.; Fechner, T.; Feuerstein, D.; Granzer, T.; Hahn, T.; Harnisch, G.; Hofmann, A.; Lesser, M.; Paschke, J.; Pankratow, S.; Plank, V.; Plüschke, D.; Popow, E.; Sablowski, D.

    2015-05-01

    PEPSI is the bench-mounted, two-arm, fibre-fed and stabilized Potsdam Echelle Polarimetric and Spectroscopic Instrument for the 2×8.4 m Large Binocular Telescope (LBT). Three spectral resolutions of either 43 000, 120 000 or 270 000 can cover the entire optical/red wavelength range from 383 to 907 nm in three exposures. Two 10.3k×10.3k CCDs with 9-μm pixels and peak quantum efficiencies of 94-96 % record a total of 92 échelle orders. We introduce a new variant of a wave-guide image slicer with 3, 5, and 7 slices and peak efficiencies between 92-96 %. A total of six cross dispersers cover the six wavelength settings of the spectrograph, two of them always simultaneously. These are made of a VPH-grating sandwiched by two prisms. The peak efficiency of the system, including the telescope, is 15 % at 650 nm, and still 11 % and 10 % at 390 nm and 900 nm, respectively. In combination with the 110 m2 light-collecting capability of the LBT, we expect a limiting magnitude of ≈ 20th mag in V in the low-resolution mode. The R = 120 000 mode can also be used with two, dual-beam Stokes IQUV polarimeters. The 270 000-mode is made possible with the 7-slice image slicer and a 100-μm fibre through a projected sky aperture of 0.74 arcsec, comparable to the median seeing of the LBT site. The 43 000-mode with 12-pixel sampling per resolution element is our bad seeing or faint-object mode. Any of the three resolution modes can either be used with sky fibers for simultaneous sky exposures or with light from a stabilized Fabry-Pérot étalon for ultra-precise radial velocities. CCD-image processing is performed with the dedicated data-reduction and analysis package PEPSI-S4S. Its full error propagation through all image-processing steps allows an adaptive selection of parameters by using statistical inferences and robust estimators. A solar feed makes use of PEPSI during day time and a 500-m feed from the 1.8 m VATT can be used when the LBT is busy otherwise. In this paper, we

  1. Wide and deep near-UV (360nm) galaxy counts and the extragalactic background light with the Large Binocular Camera

    CERN Document Server

    Grazian, A; Giallongo, E; Gallozzi, S; Fontanot, F; Fontana, A; Testa, V; Ragazzoni, R; Baruffolo, A; Beccari, G; Diolaiti, E; Di Paola, A; Farinato, J; Gasparo, F; Gentile, G; Green, R; Hill, J; Kuhn, O; Pasian, F; Pedichini, F; Radovich, M; Smareglia, R; Speziali, R; Thompson, D; Wagner, R M

    2009-01-01

    Deep multicolour surveys are the main tool to explore the formation and evolution of the faint galaxies which are beyond the spectroscopic limit with the present technology. The photometric properties of these faint galaxies are usually compared with current renditions of semianalytical models to provide constraints on the fundamental physical processes involved in galaxy formation and evolution, namely the mass assembly and the star formation. Galaxy counts over large sky areas in the near-UV band are important because they are difficult to obtain given the low efficiency of near-UV instrumentation, even at 8m class telescopes. A large instrumental field of view helps in minimizing the biases due to the cosmic variance. We have obtained deep images in the 360nm U band provided by the blue channel of the Large Binocular Camera at the prime focus of the Large Binocular Telescope. We have derived over an area of ~0.4 sq. deg. the galaxy number counts down to U=27 in the Vega system (corresponding to U=27.86 in ...

  2. Peculiarities of vernier monocular and binocular visual acuity in the retinal orthogonal meridians in patients with hypermetropic astigmatism

    Directory of Open Access Journals (Sweden)

    Владимир Александрович Коломиец

    2015-06-01

    Full Text Available It was carried out an examination of meridional vernier visual acuity in 100 patients 7-25 years old with a simple and compound hypermetropic astigmatism and refractive ambyiopia. An astigmatic component of refraction was in range 0,5- 2,5 dptr. Visual acuity on the sighting eyes after correction was 0,9- 1,0, on eyes with amblyopia 0,4 - 0,85 relative units.Methods. Visual acuity was defined by the Landolt rings of Sivtsev table. Vernier visual acuity was defined in seconds of arc from 5 km, using special computer program.Result. It was demonstrated that in patients with the simple hypertropic astigmatism diagnosis of meridional amblyopia can be specified by the comparison of data of monocular and binocular vernier visual acuity in orthogonal meridians of retinas.Conclusions. An effect of the rise of meridional binocular visual acuity in one of meridians and its absence in another one allows define selective meridional disturbances of the visual acuity

  3. Knowledge of the diversity and rivalry between technological options for the photovoltaic electric power production; Apprentissage de la diversite et competition entre options technologiques pour la production d'electricite photovoltaique

    Energy Technology Data Exchange (ETDEWEB)

    Menanteau, Ph.

    1998-05-01

    This presentation of the photovoltaic cells market development takes stock on this industry sector; The first part presents the crystalline silicon photovoltaic cells, their production, cost and performance. The second chapter is devoted to the photovoltaic cells technology diffusion by an analysis of the markets and the utilization sectors. The last part underlines the intra technological rivalry and the actors strategy showing the dominant position of the crystalline silicon, in spite of its limited capacity, to the detriment of new technologies more promising. (A.L.B.)

  4. 基于 OpenCV 的双目摄像机标定技术研究%Binocular Camera Calibration Technique Based on OpenCV

    Institute of Scientific and Technical Information of China (English)

    王长元; 邢世蒙

    2014-01-01

    摄像机标定技术作为双目立体视觉领域的一个基础性研究课题,具有很大的理论研究价值和实际应用价值。论文围绕双目立体视觉中的双目摄像机标定技术,分析基于OpenCV的双目摄像机标定的方法。基于OpenCV的双目摄像机标定比传统的定标技术更为灵活,并且具有不错的定标精度。%As a foundational research in the field of binocular stereo vision ,camera calibration technique has great theo‐retical value and practical value .This paper focuses on the binocular stereo vision camera calibration technique to analyze the binocular camera calibration method based on OpenCV .OpenCV camera calibration based on binocular is more flexible than traditional scaling techniques ,and has a good calibration accuracy .

  5. 眼眶骨折对双眼单视功能的影响及治疗%Orbital fracture: Consequen on binocular visual function and treatment

    Institute of Scientific and Technical Information of China (English)

    赵焕; 朱豫

    2013-01-01

    Normal binocular vision is important to the human modem life.In recent years,traumatic orbital fracture incidence increased year by year because of traffic accidents or boxing injuries.Binocular vision could be altered in orbital wall fractures because of strabismus,diplopia,eye movement disorders,eyeball displacement and enophthalmos.The effect of a conservative treatment is limited,and most of patients may recover their binocular vision with surgical treatment.Few postoperative diplopia could be treated with muscle surgery.The mechanisms and treatments of orbital wall fractures in relation to binocular vision are discussed.%正常双眼单视是人类现代生活不可或缺的功能.近年来,交通事故、拳击伤等造成的眼眶骨折发病率逐年增加,严重损害患者双眼单视功能,主要表现为斜视、复视和眼球运动障碍,眼球移位和内陷.保守治疗作用有限,眶壁骨折手术治疗可使多数患者恢复双眼单视,少数残留复视可通过眼肌手术消除.

  6. Stereo Vision Integration Based on Binocular Views%基于双目感知的立体视觉集成

    Institute of Scientific and Technical Information of China (English)

    杨阳

    2016-01-01

    虽然计算机视觉的应用场景拓宽,关于双目视觉的算法和理论研究达到一定的深度。双目立体视觉感知是通过双目摄像机在接近平行且距离较近的位置上获取同一场景不同角度的图像,进而通过二维图像获取三维信息。基于双目视觉工作原理,提出一种综合的双目感知立体视觉集成框架,其中主要包括图像预处理模块,立体匹配算法模块、点云融合显示模块。在其使用算法方面进行简要介绍,并达到集成处理效果。%As the application of computer vision scene is broad, the theoretical studies algorithms of binocular vision have achieved a certain depth. The binocular stereo vision is to access images in different perspectives on the same scene by binocular cameras at a close range and in parallel, and then obtain 3D information from 2D images. Puts forward a comprehensive binocular stereo vision integration framework based on the binocular visions, which includes image preprocessing module, stereo matching algorithm module, point cloud fusion and display module. Carries out the brief introduction of basic algorithms and achieves the integration.

  7. 基于OGRE的双目立体显示研究与实现%Research and Implementation of Binocular Stereoscopic Display Based on OGRE

    Institute of Scientific and Technical Information of China (English)

    王良燕; 张佑生; 高敏

    2013-01-01

    Binocular stereoscopic display is a cutting-edge technology in computer graphics which plays an important role in virtual reality.The thesis analyzes the principle of binocular stereoscopic display and a solution of binocular stereoscopic display based on OGRE (Object-Oriented Graphics Rendering Engine) and parallel binocular projection model is proposed.The solution takes full advantage of virtual camera in OGRE and viewport synthesis technology,leveraging CG script at the lower layer which brings the highest rendering efficiency.The results indicate that the solution has a good binocular stereoscopic effect with flexibility of easily loading different scene models,which is very suitable for practical applications.%双目立体显示是计算机图形学中的一项前沿技术,在虚拟现实领域发挥着重要作用.分析了双目立体显示的原理,根据平行双目投影模型,提出一种基于OGRE(面向对象图形渲染引擎)的双目立体显示方案.该方案充分利用OGRE中的虚拟摄像机和视口合成技术,并在底层结合CG脚本,保证了渲染的效率.结果表明,对于正负两种视差,该方案均有明显的立体效果,并能灵活漫游及更换不同的场景,非常适合实际应用.

  8. Incidence of vertical phoria on postural control during binocular vision: what perspective for prevention to nonspecific chronic pain management?

    Science.gov (United States)

    Matheron, Eric; Kapoula, Zoï

    2015-01-01

    Vertical heterophoria (VH) is the latent vertical misalignment of the eyes when the retinal images are dissociated, vertical orthophoria (VO) when there is no misalignment. Studies on postural control, during binocular vision in upright stance, reported that healthy subjects with small VH vs. VO are less stable, but the experimental cancellation of VH with an appropriate prism improves postural stability. The same behavior was recorded in nonspecific chronic back pain subjects, all with VH. It was hypothesized that, without refraction problems, VH indicates a perturbation of the somaesthetic cues required in the sensorimotor loops involved in postural control and the capacity of the CNS to optimally integrate these cues, suggesting prevention possibilities. Sensorimotor conflict can induce pain and modify sensory perception in some healthy subjects; some nonspecific pain or chronic pain could result from such prolonged conflict in which VH could be a sign, with new theoretical and clinical implications.

  9. Shading Beats Binocular Disparity in Depth from Luminance Gradients: Evidence against a Maximum Likelihood Principle for Cue Combination.

    Directory of Open Access Journals (Sweden)

    Chien-Chung Chen

    Full Text Available Perceived depth is conveyed by multiple cues, including binocular disparity and luminance shading. Depth perception from luminance shading information depends on the perceptual assumption for the incident light, which has been shown to default to a diffuse illumination assumption. We focus on the case of sinusoidally corrugated surfaces to ask how shading and disparity cues combine defined by the joint luminance gradients and intrinsic disparity modulation that would occur in viewing the physical corrugation of a uniform surface under diffuse illumination. Such surfaces were simulated with a sinusoidal luminance modulation (0.26 or 1.8 cy/deg, contrast 20%-80% modulated either in-phase or in opposite phase with a sinusoidal disparity of the same corrugation frequency, with disparity amplitudes ranging from 0'-20'. The observers' task was to adjust the binocular disparity of a comparison random-dot stereogram surface to match the perceived depth of the joint luminance/disparity-modulated corrugation target. Regardless of target spatial frequency, the perceived target depth increased with the luminance contrast and depended on luminance phase but was largely unaffected by the luminance disparity modulation. These results validate the idea that human observers can use the diffuse illumination assumption to perceive depth from luminance gradients alone without making an assumption of light direction. For depth judgments with combined cues, the observers gave much greater weighting to the luminance shading than to the disparity modulation of the targets. The results were not well-fit by a Bayesian cue-combination model weighted in proportion to the variance of the measurements for each cue in isolation. Instead, they suggest that the visual system uses disjunctive mechanisms to process these two types of information rather than combining them according to their likelihood ratios.

  10. Vertical binocular disparity is encoded implicitly within a model neuronal population tuned to horizontal disparity and orientation.

    Directory of Open Access Journals (Sweden)

    Jenny C A Read

    2010-04-01

    Full Text Available Primary visual cortex is often viewed as a "cyclopean retina", performing the initial encoding of binocular disparities between left and right images. Because the eyes are set apart horizontally in the head, binocular disparities are predominantly horizontal. Yet, especially in the visual periphery, a range of non-zero vertical disparities do occur and can influence perception. It has therefore been assumed that primary visual cortex must contain neurons tuned to a range of vertical disparities. Here, I show that this is not necessarily the case. Many disparity-selective neurons are most sensitive to changes in disparity orthogonal to their preferred orientation. That is, the disparity tuning surfaces, mapping their response to different two-dimensional (2D disparities, are elongated along the cell's preferred orientation. Because of this, even if a neuron's optimal 2D disparity has zero vertical component, the neuron will still respond best to a non-zero vertical disparity when probed with a sub-optimal horizontal disparity. This property can be used to decode 2D disparity, even allowing for realistic levels of neuronal noise. Even if all V1 neurons at a particular retinotopic location are tuned to the expected vertical disparity there (for example, zero at the fovea, the brain could still decode the magnitude and sign of departures from that expected value. This provides an intriguing counter-example to the common wisdom that, in order for a neuronal population to encode a quantity, its members must be tuned to a range of values of that quantity. It demonstrates that populations of disparity-selective neurons encode much richer information than previously appreciated. It suggests a possible strategy for the brain to extract rarely-occurring stimulus values, while concentrating neuronal resources on the most commonly-occurring situations.

  11. Binocular neurons in parastriate cortex: interocular 'matching' of receptive field properties, eye dominance and strength of silent suppression.

    Directory of Open Access Journals (Sweden)

    Phillip A Romo

    Full Text Available Spike-responses of single binocular neurons were recorded from a distinct part of primary visual cortex, the parastriate cortex (cytoarchitectonic area 18 of anaesthetized and immobilized domestic cats. Functional identification of neurons was based on the ratios of phase-variant (F1 component to the mean firing rate (F0 of their spike-responses to optimized (orientation, direction, spatial and temporal frequencies and size sine-wave-luminance-modulated drifting grating patches presented separately via each eye. In over 95% of neurons, the interocular differences in the phase-sensitivities (differences in F1/F0 spike-response ratios were small (≤ 0.3 and in over 80% of neurons, the interocular differences in preferred orientations were ≤ 10°. The interocular correlations of the direction selectivity indices and optimal spatial frequencies, like those of the phase sensitivies and optimal orientations, were also strong (coefficients of correlation r ≥ 0.7005. By contrast, the interocular correlations of the optimal temporal frequencies, the diameters of summation areas of the excitatory responses and suppression indices were weak (coefficients of correlation r ≤ 0.4585. In cells with high eye dominance indices (HEDI cells, the mean magnitudes of suppressions evoked by stimulation of silent, extra-classical receptive fields via the non-dominant eyes, were significantly greater than those when the stimuli were presented via the dominant eyes. We argue that the well documented 'eye-origin specific' segregation of the lateral geniculate inputs underpinning distinct eye dominance columns in primary visual cortices of mammals with frontally positioned eyes (distinct eye dominance columns, combined with significant interocular differences in the strength of silent suppressive fields, putatively contribute to binocular stereoscopic vision.

  12. Disfunciones visuo-perceptivas, oculomotoras, acomodativas y binoculares en niños con trastornos por déficit de atención e hiperactividad

    OpenAIRE

    Pardo Pérez, María Carmen

    2009-01-01

    1) Determinar el grado de desarrollo de las habilidades visuoperceptivas, oculomotoras, acomodativas y binoculares en estudiantes con TDAH. 2) Comparar las habilidades visuales y visuoperceptivas entre un grupo de estudiantes con TDAH y otro que no presenta este trastorno. 3) Analizar qué habilidades visuoperceptivas (discriminación, memoria visual, figura-fondo, integración visual…) y oculomotoras presentan unos valores más deteriorados en el grupo de estudiantes que presentan...

  13. Improvement in the field of binocular single vision following bilateral phacoemulsification with toric intraocular lens implantation in a patient with a partial third nerve palsy.

    Science.gov (United States)

    Subash, Malavika; Sloper, John J; Wilkins, Mark R

    2010-12-01

    A 44-year-old female teacher with partial third (oculomotor) nerve palsy had a small central field of binocular single vision (BSV) following three strabismus procedures. Over several years her field of BSV constricted further, coincident with the development of myopia in one eye secondary to early lens change and in the presence of significant astigmatism. Following bilateral lens extraction with toric intraocular lens implants, her field of BSV reexpanded.

  14. Ambiguity Revealed

    OpenAIRE

    Subir Bose; Matthew Polisson; Ludovic Renou

    2012-01-01

    We derive necessary and suffcient conditions for data sets composed of state-contingent prices and consumption to be consistent with two prominent models of decision making under ambiguity: variational preferences and smooth ambiguity. The revealed preference conditions for the maxmin expected utility and subjective expected utility models are characterized as special cases.

  15. Ambiguity revealed

    OpenAIRE

    Bayer, Ralph-C; Bose, Subir; Polisson, Matthew; Renou, Ludovic

    2013-01-01

    We derive necessary and sufficient conditions for data sets composed of state-contingent prices and consumption to be consistent with two prominent models of decision making under uncertainty: variational preferences and smooth ambiguity. The revealed preference conditions for subjective expected utility, maxmin expected utility, and multiplier preferences are characterised as special cases. We implement our tests on data from a portfolio choice experiment.

  16. Magnetoencephalographic Activity Related to Conscious Perception Is Stable within Individuals across Years but Not between Individuals

    DEFF Research Database (Denmark)

    Sandberg, Kristian; Barnes, Gareth Robert; Rees, Geraint;

    2014-01-01

    the generalization across time within individuals and across different individuals. We trained classification algorithms to decode conscious perception from neural activity recorded during binocular rivalry using magnetoencephalography (MEG). The classifiers were then used to predict the perception of the same...

  17. Research Progress of Binocular Vision Recovery in Concomitant Strabismus%共同性斜视双眼视觉重建的研究进展

    Institute of Scientific and Technical Information of China (English)

    陈莉莉

    2011-01-01

    Concomitant strabismus is one of the common ocular-disease, which is the common cause of abnormal binocular vision clinically. At present, surgery is the main treatment, which is considered by most of professors at home and abroad to be effctive to improve binocular vision in varying degrees, however further discussion is still needed, such as timing of operation. Vision exercise is given more consideration gradually,but more research is needed to demonstrate its effectiveness and show how to use it correctly. Here is to review the treatment of binocular vision recovery or reconstruction.%共同性斜视是眼科常见病,是临床上造成双眼视觉功能异常的常见原因.目前手术是主要的治疗方法,国内外多数学者都认为斜视手术矫正眼位后双眼视觉功能有不同程度的提高,但关于斜视手术仍有很多值得探讨的地方,如手术时机.视觉训练能改善双眼视觉,但它的有效性、规范性等需进一步研究.现就共同性斜视双眼视觉恢复或重建的治疗予以综述.

  18. Simultaneous Water Vapor and Dry Air Optical Path Length Measurements and Compensation with the Large Binocular Telescope Interferometer

    CERN Document Server

    Defrère, D; Downey, E; Böhm, M; Danchi, W C; Durney, O; Ertel, S; Hill, J M; Hoffmann, W F; Mennesson, B; Millan-Gabet, R; Montoya, M; Pott, J -U; Skemer, A; Spalding, E; Stone, J; Vaz, A

    2016-01-01

    The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 $\\mu$m). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illus...

  19. A temperature inversion in WASP-33b? Large Binocular Telescope occultation data confirm significant thermal flux at short wavelengths

    CERN Document Server

    von Essen, C; Albrecht, S; Antoci, V; Smith, A M S; Dreizler, S; Strassmeier, K G

    2015-01-01

    We observed a secondary eclipse of WASP-33b quasi-simultaneously in the optical (~0.55 {\\mu}m) and the near-infrared (~1.05 {\\mu}m) using the 2x8.4 m Large Binocular Telescope. WASP-33 is a {\\delta} Scuti star pulsating with periods comparable to the eclipse duration, making the determination of the eclipse depth challenging. We use previously determined oscillation frequencies to model and remove the pulsation signal from the light curves, isolating the secondary eclipse. The determined eclipse depth is dF = 1.03 +/- 0.34 parts per thousand, corresponding to a brightness temperature of Tb = 3398 +/- 302 K. Combining previously published data with our new measurement we find the equilibrium temperature of WASP-33b to be Tb = 3358 +/- 165 K. We compare all existing eclipse data to a blackbody spectrum, to a carbon-rich non-inverted model and to a solar composition model with an inverted temperature structure. We find that current available data on WASP-33b's atmosphere can be best represented by a simple black...

  20. Revealing Rembrandt

    Directory of Open Access Journals (Sweden)

    Andrew J Parker

    2014-04-01

    Full Text Available The power and significance of artwork in shaping human cognition is self-evident. The starting point for our empirical investigations is the view that the task of neuroscience is to integrate itself with other forms of knowledge, rather than to seek to supplant them. In our recent work, we examined a particular aspect of the appreciation of artwork using present-day functional magnetic resonance imaging (fMRI. Our results emphasised the continuity between viewing artwork and other human cognitive activities. We also showed that appreciation of a particular aspect of artwork, namely authenticity, depends upon the co-ordinated activity between the brain regions involved in multiple decision making and those responsible for processing visual information. The findings about brain function probably have no specific consequences for understanding how people respond to the art of Rembrandt in comparison with their response to other artworks. However, the use of images of Rembrandt’s portraits, his most intimate and personal works, clearly had a significant impact upon our viewers, even though they have been spatially confined to the interior of an MRI scanner at the time of viewing. Neuroscientific studies of humans viewing artwork have the capacity to reveal the diversity of human cognitive responses that may be induced by external advice or context as people view artwork in a variety of frameworks and settings.

  1. Screening for retinopathy of prematurity-a comparison between binocular indirect ophthalmoscopy and RetCam 120

    Directory of Open Access Journals (Sweden)

    Shah Parag

    2006-01-01

    Full Text Available Aim: To compare the photographic screening for retinopathy of prematurity (ROP using RetCam 120 with binocular indirect ophthalmoscope (BIO, which is the current gold standard. Setting and Design: Prospective, comparative study. Materials and Methods: A total of 87 RetCam examinations were performed on 27 premature babies. They were stored in a separate file after deleting the identifying information. At the same visit using the BIO with scleral depression, an experienced vitreoretinal surgeon evaluated the fundus in detail. A masked examiner then evaluated the RetCam photographs for presence or absence of ROP, the stage and zone of the disease, and the presence or absence of plus disease. These data were then compared with the BIO findings to determine the sensitivity, specificity, and the positive and negative predictive values of the method. Results: ROP was detected in 63 of 87 examinations by BIO and in 56 of 87 RetCam examinations. Nine RetCam examinations were false-negative and two were false-positive. Sensitivity of RetCam was 85.71% (54/63 and specificity was 91.66% (22/24. The positive and negative predictive values were 96.43% and 70.97% respectively. Conclusion: Nine cases having ROP were missed by the RetCam. All these cases were either in zone 3 or the outer part of zone 2, which later regressed. These were missed mostly because of the restricted mobility of the camera head caused by its size and the barrier caused by the lid speculum arms. No case of threshold ROP was missed. RetCam may replace BIO for screening of ROP.

  2. Embedded Binocular Stereo Vision Ranging System%嵌入式双目立体视觉测距系统

    Institute of Scientific and Technical Information of China (English)

    文成维; 陈文建; 詹泳

    2012-01-01

    设计和研究了一种基于S3C2440硬件平台和嵌入式Linux双目立体视觉测距系统.该系统通过使用两个USB摄像头同步采集图像数据,并利用OpenCV对采集的两幅图像的数据进行处理,计算目标物在两幅图像中的像素偏差,进而算出目标物到摄像头平面的距离,在论文中以车牌作为目标物.同时该系统用Qt/Embedded实现LED实时显示图像和数据.整个系统建立在嵌入式架构上,能独立完成图像采集,数据处理,实时显示等功能.只要改变定位算法,则能测出任意目标物的距离.%The paper designs and researches a binocular stereo measuring system based on S3C2440 hardware platform and embedded Linux. The system captures images data in synchronization by using 2 USB cameras, and then processes the images data in OpenCV Lib. Finally, calculate the pixel deviation of the target in two images, and then calculate the distance from the target to camera plane, license plate be seen as the target in the paper. At the same time, the system displays the images and dates on LED with Qt/Embedded GUI in real time. The whole system is built on an embedded architecture, able to capture images and process data and real-time display data independently. When change location algorithm, we can calculate the distance of any targets.

  3. 3D-MAD: A Full Reference Stereoscopic Image Quality Estimator Based on Binocular Lightness and Contrast Perception.

    Science.gov (United States)

    Zhang, Yi; Chandler, Damon M

    2015-11-01

    Algorithms for a stereoscopic image quality assessment (IQA) aim to estimate the qualities of 3D images in a manner that agrees with human judgments. The modern stereoscopic IQA algorithms often apply 2D IQA algorithms on stereoscopic views, disparity maps, and/or cyclopean images, to yield an overall quality estimate based on the properties of the human visual system. This paper presents an extension of our previous 2D most apparent distortion (MAD) algorithm to a 3D version (3D-MAD) to evaluate 3D image quality. The 3D-MAD operates via two main stages, which estimate perceived quality degradation due to 1) distortion of the monocular views and 2) distortion of the cyclopean view. In the first stage, the conventional MAD algorithm is applied on the two monocular views, and then the combined binocular quality is estimated via a weighted sum of the two estimates, where the weights are determined based on a block-based contrast measure. In the second stage, intermediate maps corresponding to the lightness distance and the pixel-based contrast are generated based on a multipathway contrast gain-control model. Then, the cyclopean view quality is estimated by measuring the statistical-difference-based features obtained from the reference stereopair and the distorted stereopair, respectively. Finally, the estimates obtained from the two stages are combined to yield an overall quality score of the stereoscopic image. Tests on various 3D image quality databases demonstrate that our algorithm significantly improves upon many other state-of-the-art 2D/3D IQA algorithms.

  4. 基于Harris-SIFT算法的双目立体视觉定位%Object Location Technique for Binocular Stereo Vision Based on Harris-SIFT Algorithm

    Institute of Scientific and Technical Information of China (English)

    李耀云; 贾敏智

    2013-01-01

    针对基于尺度空间对图象保持不变性的SIFT算法在双目立体视觉应用时实时性差、误匹配等问题,提出一种运用Harris-SIFT算法进行双目立体视觉定位方法.通过介绍双目立体视觉的模型原理,利用Harris-SIFT算法从左右摄像机分别获取的图像中检测目标,并获取匹配目标的特征点,对两幅图像中目标物体的坐标标定,通过计算可得到目标物体的深度距离,还原其三维信息.实验证明,运用Harris-SIFT算法使该系统的实时性能和距离精度得到提高.%The object location technique for binocular stereo vision has some problems of the poor real-time performance and the mismatching based on the SIFT algorithm of the scale space to image keep invariance.A method of the object location technique for binocular stereo vision developed based on the Harris-SIFT algorithm is presented.Through the introduction of the binocular stereo vision model principle,adopting new Harris-SIFT algorithm to get the camera image form the two detection target,and for matching the feature points of the target,according to the target object coordinate calibration two images of the two images.Through the calculation can get the depth of the object distance,reducing the 3d information.The experiments improve the real-time performance and the accuracy distance based on the Harris-SIFT algorithm.

  5. The evaluation of binocular visual field and clinical application of glaucoma%双眼视野评估及其在青光眼研究中的应用

    Institute of Scientific and Technical Information of China (English)

    吴娅莉; 钟华

    2016-01-01

    视野是重要的视功能之一.在日常生活中,人的视功能是由双眼同时视产生,因此评估双眼视野对于了解患者的真实视功能非常重要.目前双眼视野评估方法主要包括计算机自动视野计测定法和双眼视野整合法,而双眼视野整合法包括双眼总和法、最佳位点法、最佳眼法及双眼平均法.本文就双眼视野评估的重要意义、双眼视野整合法及其在日常生活和临床青光眼研究中的实际应用进行综述,希望能对临床工作和科学研究提供参考和帮助.%Visual field is an important means of the assessment of visual function.In our daily life,the actual visual function is consist of both eyes.Therefore,the binocular visual field test is significant to understand the real visual function.Currently,the binocular vision assessment methods included Esterman visual test and Integrated visual fields.The IVF includes:binocular summation,best location,best eye and average eye.In this review,the significance of binocular visual field inspection,binocular visual field integration methods and its practical application in daily life and clinical glaucoma research work are summarized.We hope that it can do some favors to clinical and scientific researches of assessment and application of binocular visual field.

  6. 双目立体视觉的概念与分析%The Concept and Analysis of Binocular Stereo Vision

    Institute of Scientific and Technical Information of China (English)

    王青伟

    2014-01-01

    Binocular stereo vision is one method which can obtain the 3D information by processing two images from the cameras. The 3D information is presented by depth image. The stereo vision system can be used in auto navigation, industrial detection, visual surveil ance, and drive assistance system. With the rapid evolution of hardware, binocular vision based application wil become more and more popular.%双目立体视觉是在对人类视觉系统研究的基础上,通过双目图像的处理来获取物体三维几何信息,其结果表现为深度图,再经过进一步处理得到三维空间中的物体信息的方法。双目立体视觉的研究具有重要的应用价值,包括机器人的自主导航、工业检测、视觉监控以及车辆辅助驾驶系统等。随着计算机硬件的高速发展,基于双目立体视觉的应用越来越多地呈现在人们面前。

  7. 基于双目立体视觉的深度信息测量%Depth Information Measurement Based on Binocular Stereo Vision

    Institute of Scientific and Technical Information of China (English)

    王玉翰; 金波

    2015-01-01

    介绍了双目立体视觉三角测距原理和视觉测量系统,双目摄像机拍摄彩色图像,提取颜色、轮廓、纹理等识别特征用于目标区域识别。采用区域匹配算法获得视差图,根据视差计算目标区域的三维坐标信息。完成了目标测量实验并对实验结果进行分析。%The triangulation ranging principle of binocular stereo vision and vision measurement system were presented, and color images were taked from binocular cameras. Color,contour,texture features were extracted from the image for target area recognition. Obtaining disparity map from color images by region based stereo matching algorithms, three-dimensional coordinate information of target area were calculated according to the disparity map. Target measurement experiment and analyse of the results were completed.

  8. 远、近视性屈光参差视功能对比研究%Comparative study of myopic and hyperopic anisometropia on binocular vision

    Institute of Scientific and Technical Information of China (English)

    罗俊; 漆争艳; 何容; 王平; 唐璟; 向剑波; 杨俊芳

    2014-01-01

    AIM: To investigate the effect of both myopic and hyperopic anisometropia on binocular vision. METHODS: Totally 238 patients with corrected anisometropia and 30 normal children were tested with both stereogram and synoptophore for their near stereoacuity and binocular vision. The correlation of anisometropia and binocular vision was studied statistically. RESULTS:The number of normal near stereoacuity and distance fusion range of myopic anisometropia was significantly higher than that of hyperopic anisometropia. A few of hyperopic anisometropia had normal stereopsis. Most of low anisometropia group had sub -normal stereopsis, while high, severe anisometropia group without stereopsis.Most of myopic anisometropia group had normal stereopsis or sub-normal stereopsis. CONCLUSION:The hyperopic anisometropia produces a more profound effect. Relationship between anisometropia and stereopsis are analyzed according to nature.%目的:对比分析远、近视性屈光参差对患者双眼视功能的影响。  方法:对238例屈光矫正后的屈光参差者和30例正常者进行近立体视和同视机三级视功能检查,并记录其结果。  结果:近视性屈光参差远、近立体视及融合功能正常者的例数高于远视性屈光参差者。远视性屈光参差组有正常立体视者少,低度屈光参差组以亚正常立体视者为主,而高、重度屈光参差组多无立体视;近视性屈光参差组多有正常立体视或亚正常立体视。  结论:近视性屈光参差的双眼视功能总体优于远视性屈光参差,但屈光参差与立体视的关系应按性质分别进行分析。

  9. 双眼视觉与其神经机制的探讨%The neuronal mechanism of clinical binocular visual function

    Institute of Scientific and Technical Information of China (English)

    卢炜

    2012-01-01

    斜视弱视治疗前后的双眼视觉现象均有神经解剖生理学、心理物理学基础,其相互关联并印证.在注视方向的视界圆内,视网膜对应分为两个区,即双眼黄斑对应区和右眼颞侧视网膜与左眼鼻侧视网膜对应区,右眼的鼻侧视网膜与左眼颞侧视网膜对应区.这两个区域又分别对应传入的小细胞通路和大细胞通路.小细胞通路主要处理形觉、色觉和精细立体视觉,大细胞通路处理运动和空间信息及粗的局部立体视觉.加深和梳理这些相互连接有利于对双眼视觉的理解和进一步探讨.%There are interrelation among psychophysics, neuronal anatomy neurophysiology and clinical binocular vision phenomena. Based on neuronal anatomy, there are two corresponding area bilateral retina projecting at fixate direction of Vieth-M(u)ller circle. There are corresponding area between binocular fovea, the temporal area of retina in right eye and nasal area of retina in left eye, the nasal retina in left eye and the temporal retina in right eye. The two separated corresponding area projecte to the brain via different pathway. The parvocellular pathway is mostly dealing with formcolor and fine stereopsis. The magnocellular pathway is mostly dealing with movement space sign and granulate stereopsis. It is very helpful for our practice to understand the clinical binocular vision phenomena more deeply based on this neuronal anatomy. (Ophthalmol CHN,2012, 21 :297-301)

  10. Driving with binocular visual field loss? A study on a supervised on-road parcours with simultaneous eye and head tracking.

    Directory of Open Access Journals (Sweden)

    Enkelejda Kasneci

    Full Text Available Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs that may critically interfere with quality of life and driving licensure. The aims of this study were (i to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed of ten patients with homonymous visual field defects (HP, including four patients with right (HR and six patients with left homonymous visual field defects (HL, ten glaucoma patients (GP, and twenty age and gender-related ophthalmologically healthy control subjects (C during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on

  11. Driving with binocular visual field loss? A study on a supervised on-road parcours with simultaneous eye and head tracking.

    Science.gov (United States)

    Kasneci, Enkelejda; Sippel, Katrin; Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

    2014-01-01

    Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the

  12. The clinical observation and etiologies of binocular recurrent optic neuritis%双眼复发性视神经炎的病因研究

    Institute of Scientific and Technical Information of China (English)

    韦企平; 周剑; 孙艳红; 宫晓红; 路明

    2010-01-01

    目的 明确双眼复发性视神经炎的病因及和多发性硬化等脱髓鞘疾病的相关性.方法 对1992~2006年间38例双眼复发性视神经炎进行回顾性分析,并随访调查最终病因.结果 该38例随访时间9~96个月,平均(45.8±20.83)个月.19例(50%)诊断为中枢神经系统脱髓鞘疾病,其中多发性硬化14例(36.8%),视神经脊髓炎5例(13.2%).另有19例(50%)病因不明.结论 双眼复发性视神经炎的重要病因是以多发性硬化为主的中枢神经系统脱髓鞘疾病,这类视神经炎在病因不明时应建立长期随访制度.%Objective To define the clinical characters and etiologies of binocular recurrent optic neuritis (ON), and to estimate the relations of ON to multiple sclerosis (MS) or neuromyelitis optica (NMO).Methods Retrospective medical record review of both clinical and laboratory evidence supporting the diagnosis of 38 patients with binocular recurrent ON between 1992 and 2006, and all cases had been followed-up for 9-96 months (45.8± 20.83M). Results The conversion rate to NMO was 13.2% and to MS, 36.8%. Nineteen patients (50%) of 38 cases were diagnosed eventually to an inflammatory demyelinating disease of the central nervous system. Conclusions The inflammatory demyelinating diseases of the central nervous system are the important etiologies of binocular recurrent ON.

  13. An investigation on binocular summation response of visual evoked potential in children with hyperopia amblyopia%弱视儿童双眼总和视觉诱发电位变化的研究

    Institute of Scientific and Technical Information of China (English)

    于春红; 廖瑜俊; 杨洋; 邓燕; 彭小维; 鄢涛; 殷小龙

    2009-01-01

    Objective Conventional examination for vision function adopts subjective psychophysics methods.Pattern visual evoked potential (P-VEP) binocular summation response is a new objective way for the test of vision function.But its clinical value in evaluating vision function of amblyopia children is still in controversy.This study was to explore the binocular vision and the feature of P-VEP binocular summation in children with amblyopia and evaluate the significance of P-VEP binocular summation in binocular vision.MethodsThis is a case-controlled study.P-VEP binocular summation response and single ocular P-VEP response was respectively recorded in 151 hyperopia amblyopia children and 80 age- and gender-matched normal children.P-VEP response from children with hyperopia amblyopia was recorded under the corrected vision.The hyperopia amblyopia was diagnosed based on the standard of National Children Amblyopia and Strabismus Prevention and Treatment Working Group.The feature of P-VEP binocular summation was further analyzed and compared with monocular VEP response.Informed consent was obtained from each subject or custodian prior to the trail.ResultsNo significant difference was found in latency between P-VEP binocular summation response and monocular P-VEP response whether amblyopia children or normal children(P>0.05).Binocular response/monocular response value in amblyopia children was lower than that in normal children(P<0.05).Binocular response/monocular response value in mild or moderate amblyopia children was higher than that in severe amblyopia children(P<0.05).Binocular response/monocular response value was significantly reduced in the children with binocular vision than in the children without binocular vision (P<0.05).ConclusionP-VEP binocular vision,acting as an evaluation factor,could impartially reflect the function of binocular vision of amblyopia children.%目的 探讨弱视儿童双眼视功能及总和图形视觉诱发电位(P-VEP)反应的特

  14. Changes in N-methyl-D-aspartate receptor 2A subunit expression caused by binocular form deprivation and chondroitin sulfate proteoglycan degradation

    Institute of Scientific and Technical Information of China (English)

    Mingming Liu; Wei Qin; Hanping Xie

    2011-01-01

    Light deprivation is known to induce a significant decrease in the percentage of N-methyl-D- aspartate receptor 2A subunit (NR2A)-expressing neurons during development. The purpose of this study was to investigate the effects of binocular form deprivation (BFD) and chondroitin sulfate proteoglycan (CSPG) degradation on NR2A expression via an immunohistochemical study, around the end of a critical developmental period. The results show that the positive staining of NR2A in the normal rat visual cortex increases gradually from postnatal 3-5 weeks (P 0.05). The positive staining of NR2A in the CSPG-treated group was insignificant compared with the BFD group at the same time point from 4 weeks to 7 weeks (P > 0.05). Thus, the effect of BFD on NR2A expression in the rat visual cortex was similar to that of CSPG degradation around the end of the critical developmental period.

  15. Óptica Fisiológica: el sistema óptico del ojo y la visión binocular

    OpenAIRE

    Puell Marín, María Cinta

    2006-01-01

    Se trata de una obra básica de carácter didáctico sobre el sistema óptico del ojo, la formación de la imagen retiniana, el proceso de la acomodación, las ametropías y su compensación, y los mecanismos sensoriales y oculomotores de la visión binocular. Para que los conceptos se puedan asimilar fácilmente, la exposición teórica se ha complementado con los ejemplos numéricos y los diseños gráficos imprescindibles para alcanzar la deseada familiaridad con la materia.

  16. Design of Augmented Reality Evaluation System Based on Binocular Vision%基于双目视觉的增强现实模型系统设计

    Institute of Scientific and Technical Information of China (English)

    陈春妃; 陈琼; 汤勇明

    2016-01-01

    To improve monocular vision shortcoming of unrealistic,uncomfortable and small range users,an augment⁃ed reality evaluation system is proposed,which selects high resolution,wide color gamut and high integration 2 mm× 17 mm micro OLED display as an imaging image source,large size BS prism and a concave mirror as an imaging ele⁃ment,control the image magnification to improve the field of view. The system can achieve high clarity and stability of monocular and binocular augmented reality imaging effect. With a multi-dimensional adjustable degree,the magni⁃fication times can be from one to infinite,the eyes’district and binocular image synthesis angle also can be adjusted.%该模型的研究是为了改善目前单目增强现实设备存在着视场小、成像不逼真、单目观察、适应人群窄等问题。模型系统选用高分辨率、宽色域、高集成度2 mm×17 mm OLED微显示器作为成像像源,大尺寸BS棱镜和凹面镜作为成像元件,合理控制图像放大倍率,提高视场;该系统可以实现高清晰稳定的单目及双目增强现实成像效果,具有多维的可调节度,包括调节放大倍数在1~∞内精确微调、眼距和双目图像合成角度等。

  17. Research on Location and Crawling of Workpiece Based on Binocular Vision%基于双目视觉的工件定位与抓取研究

    Institute of Scientific and Technical Information of China (English)

    朱代先

    2011-01-01

    In order to solve the workpiece recognition, location and crawling problem in the process of manufacturing, a new method of workpiece recognition and location based on binocular stereo vision is proposed.The SIFT algorithm is used to extract feature of each workpiece, the template matching method is used to identify Workpiece , and workpiece three-dimensional information is obtained by using binocular vision.Thus robot crawling task can be implemented.MATLAB and VC+ + is used to program system software.Experimental results demonstrate the good results of this method.%针对生产制造过程中工件的自动定位、识别与抓取等问题,研究基于双目立体视觉的工件识别定位方法;对每个工件进行SIFT特征提取,采用模板匹配方法实现工件的识别.用形态学方法获得工件特征点的二维信息,结合双目立体视觉标定技术得到工件的三维坐标,为机器人抓取工件提供信息;在实验中,相机标定、匹配识别与三维定位程序在MATLAB环境中执行,应用MATLAB和VC++混合编程技术将获得的工件信息传递给机器人的控制程序,实现了机器人对工件的在线实时抓取.

  18. The binocular vision of pediatric ocular trauma%儿童眼外伤治疗前后双眼视觉功能观察

    Institute of Scientific and Technical Information of China (English)

    许之娟; 刘桂香; 王玲; 张新爱; 李瑞凤

    2011-01-01

    Objective To observe the binocular vision in 76 pediatric ocular trauma, and analysis its relative factor. Methods There were 76 children(76 eyes) of 3 to 14 years old with ocular trauma. We examined their vision after primary wound repair. According the vision, we divided them into three groups: ≤0. 3,0.4-0.6 and ≥0.6. We divided the children of different ages into three groups according to the fusion or stereopsis using AIT-1000 synoptophore and Titmus stereogram:3 ~ 5 years old、6 ~ 7 years old、8 ~ 14years old. The vision was compared before and after treatment, the difference of binocular vision between different vision and different age were analysed. Results The binocular vision of difference visual:no patients had binocular vision if the vision less than 0. 3. 50 patients had a vision of more than 0. 4, only 39 patients have the function of fusion, 25 patients have far stereopsis,33 patients have near stereopsis. In the 39 patients with visual function of fusion, the difference between visual acuity of 0.4 ~0.6 and of ≥0.6 had statistical significance (P <0.05 ) ,the later one had more cases with visual function of fusion,far stereopsis and near stereopsis. The fusion 、far or near stereopsis of 6 ~7 years old group were less than the 3 ~5 years group and the 8 ~ 14 years group ( P < 0.05 ). The fusion 、far or near stereopsis of 3 ~ 5 years group had no difference compared with 8 ~ 14 years group ( P > 0.05). Conclusion The recovery of binocular vision is positive related to the recovery of vision. The recoveries of binocular vision of children aged 6 to 7 years were poor compared with the children aged 3 to 5 and children aged 8 to 14 years old.%目的 观察儿童眼外伤76例治疗后的双眼视功能,并对其相关因素进行分析.方法 3~14岁儿童眼外伤76例(76眼),于眼外伤一期修复后检查视力,分≤0.3,0.4~0.6和≥0.6 3组.使用AIT-1000型同视机及Titmus检查治疗后患儿的融合

  19. The role of sensory ocular dominance on through-focus visual performance in monovision presbyopia corrections.

    Science.gov (United States)

    Zheleznyak, Len; Alarcon, Aixa; Dieter, Kevin C; Tadin, Duje; Yoon, Geunyoung

    2015-01-01

    Monovision presbyopia interventions exploit the binocular nature of the visual system by independently manipulating the optical properties of the two eyes. It is unclear, however, how individual variations in ocular dominance affect visual function in monovision corrections. Here, we examined the impact of sensory ocular dominance on visual performance in both traditional and modified monovision presbyopic corrections. We recently developed a binocular adaptive optics vision simulator to correct subjects' native aberrations and induce either modified monovision (1.5 D anisometropia, spherical aberration of +0.1 and -0.4 μm in distance and near eyes, respectively, over 4 mm pupils) or traditional monovision (1.5 D anisometropia). To quantify both the sign and the degree of ocular dominance, we utilized binocular rivalry to estimate stimulus contrast ratios that yield balanced dominance durations for the two eyes. Through-focus visual acuity and contrast sensitivity were measured under two conditions: (a) assigning dominant and nondominant eye to distance and near, respectively, and (b) vice versa. The results revealed that through-focus visual acuity was unaffected by ocular dominance. Contrast sensitivity, however, was significantly improved when the dominant eye coincided with superior optical quality. We hypothesize that a potential mechanism behind this observation is an interaction between ocular dominance and binocular contrast summation, and thus, assignment of the dominant eye to distance or near may be an important factor to optimize contrast threshold performance at different object distances in both modified and traditional monovision.

  20. Binocular lens treatment in tree shrews: Effect of age and comparison of plus lens wear with recovery from minus lens-induced myopia.

    Science.gov (United States)

    Siegwart, John T; Norton, Thomas T

    2010-11-01

    We examined normal emmetropization and the refractive responses to binocular plus or minus lenses in young (late infantile) and juvenile tree shrews. In addition, recovery from lens-induced myopia was compared with the response to a similar amount of myopia produced with plus lenses in age-matched juvenile animals. Normal emmetropization was examined with daily noncycloplegic autorefractor measures from 11 days after natural eye-opening (days of visual experience [VE]) when the eyes were in the infantile, rapid growth phase and their refractions were substantially hyperopic, to 35 days of VE when the eyes had entered the juvenile, slower growth phase and the refractions were near emmetropia. Starting at 11 days of VE, two groups of young tree shrews wore binocular +4 D lenses (n=6) or -5 D lenses (n=5). Starting at 24 days of VE, four groups of juvenile tree shrews (n=5 each) wore binocular +3 D, +5 D, -3 D, or -5 D lenses. Non-cycloplegic measures of refractive state were made frequently while the animals wore the assigned lenses. The refractive response of the juvenile plus-lens wearing animals was compared with the refractive recovery of an age-matched group of animals (n=5) that were myopic after wearing a -5 D lens from 11 to 24 days of VE. In normal tree shrews, refractions (corrected for the small eye artifact) declined rapidly from (mean±SEM) 6.6±0.6 D of hyperopia at 11 VE to 1.4±0.2 D at 24 VE and 0.8±0.4 D at 35 VE. Plus 4 D lens treatment applied at 11 days of VE initially corrected or over-corrected the young animals' hyperopia and produced a compensatory response in most animals; the eyes became nearly emmetropic while wearing the +4 D lenses. In contrast, plus-lens treatment starting at 24 days of VE initially made the juvenile eyes myopic (over-correction) and, on average, was less effective. The response ranged from no change in refractive state (eye continued to experience myopia) to full compensation (emmetropic with the lens in place

  1. Autonomous Mapping for Robot Using a Combination of Binocular Stereo Vision and GSOM Algorithm%双目立体视觉和GSOM相结合的机器自主地图构建方法

    Institute of Scientific and Technical Information of China (English)

    于乃功; 王丽

    2011-01-01

    双目立体视觉和自组织可增长特征映射图GSOM (Growing Self-organizing Map)相结合的机器人地图构建方法首先利用双目立体摄像机采集图像,借助双目立体视觉处理技术,将采集到的图像信息转化成神经网络的训练样本;然后利用GSOM的地图绘制算法,通过不断增加新的神经元实现网络规模的增长,用441个SOM神经元便表示了2000个样本点的环境特征信息的拓扑地图,体现了对输入样本分布的逼近特性;实验结果表明双目立体视觉和GSOM相结合的机器人自主地图构建方法可行,并表现出类似生物的自主智能行为.%Autonomous mapping for robot using a combination of binocular stereo vision and GSOM (Growing Self-organizing Map) Algorithm collects images using a binocular stereo camera. After treatment of binocular stereo vision technology, image information generates neural network training samples. Appling GSOM algorithm by continuously increasing new neurons in the growth of network scale, the algorithm uses 441 SOM neurons generate a topologic map which describes 2000 sample' s environmental information and reflects the approximation characteristics of input data distribution. Through testing GSOM mapping algorithm, the experimental results show that autonomous mapping for robot using a combination of binocular stereo vision and GSOM algorithm is feasible; and the system shows similar biological behaviours of autonomous intelligence.

  2. 基于双目视觉的机器人自定位方法研究%Robot autonmouls localization method study based on binocular vision

    Institute of Scientific and Technical Information of China (English)

    张华; 夏菠

    2015-01-01

    研究了一种利用双目立体视觉的机器人自定位方法。首先提取双目图像序列的 Harris 角点特征,并计算其水平与垂直方向上的 Sobel 响应,基于此响应,采用绝对误差累计的最小窗口查找(SAD)原理进行立体匹配。将改进的 RANSAC 算法用于特征匹配点优化中,利用高斯牛顿迭代法求解机器人位姿,实现了机器人的自定位。室内、外实验,及与 BoofCV 视觉库中的立体视觉定位算法的对比分析,证明该方法在运算速度、定位精度和稳定性等方面均能满足实际应用需求。%A robot autonomous localization method based on binocular vision image sequences was studied.Harris corner features were extracted with the binocular vision image sequence and Sobel fil-ter responses of horizontal and vertical was simply compared to each other by using sum of absolute differences error metric,and matching feature points based on the responses value.The improved RANSAC algorithm was used for feature matching optimization.Finally the gauss-newton iterative method was used for solving over determined nonlinear equations of robot pose estimation,and the o-rientation of the robot was realized.Through indoor and outdoor scene experiments,as well as com-paring with the stereo visual odometry algorithm in BoofCV visual library,experiments show that the proposed approach can meet the application requirements in terms of accuracy,stability and run-time.

  3. Binocular accommodative function in patients with intermittent exotropia%间歇性外斜视的双眼调节功能

    Institute of Scientific and Technical Information of China (English)

    王小娟; 赵堪兴

    2013-01-01

    目的 研究间歇性外斜视的双眼调节功能.方法 前瞻性病例对照研究.入选年龄在18~40岁的间歇性外斜视组76例,正常对照组40例,用MEM动态检影的方法测量双眼注视40 cm处调节视标时主导眼与非主导眼的调节反应、正/负相对调节(PRA/NRA)、斜视度.对数据进行t检验、秩和检验和相关分析.结果 间歇性外斜视组48只(63%)主导眼表现为调节超前,调节反应平均为(-0.32±0.57)D;62只(81%)非主导眼表现为调节滞后,非主导眼调节反应平均为(+0.36±0.44) D;主导眼与非主导眼之间的调节反应差异有统计学意义(Z=-7.01,P<0.01).正常对照组主导眼调节反应为(+0.34±0.28)D,间歇性外斜视组主导眼的调节反应与对照组主导眼间差异有统计学意义(Z=-6.36,P<0.01).主导眼调节反应量与斜视度之间呈负相关(r=-0.67,P<0.01).间歇性外斜视组PRA平均为(-4.03±0.82)D,对照组为(-3.09±0.74)D,差异有统计学意义(t=6.05,P<0.01);间歇性外斜视组NRA平均为(+1.96±0.56)D,对照组为(+2.23±0.34)D,差异有统计学意义(t=-2.82,P<0.01).结论 间歇性外斜视者在双眼注视近距离视标时主导眼与非主导眼调节反应不一致;在集合保持固定的情况下间歇性外斜视者处于调节紧张难以放松的状态.%Objective To investigate the binocular accommodative function of patients with intermittent exotropia.Methods Seventy-six patients aged 18 to 40 years with intermittent exotropia and 40 normal controls were recruited for a prospective case control study.Accommodative responses in dominant and nondominant eyes were tested using MEM (monocular estimate method) dynamic retinoscopy.The testing measured positive relative accommodation/negative relative accommodation (PRA/NRA) and deviation to a 40 cm target with binocular viewing.The data were analyzed by a nonparametric test,t-test and correlation analysis.Results During binocular viewing at the 40 cm

  4. Israel and Iran: A Dangerous Rivalry

    Science.gov (United States)

    2011-01-01

    Times, February 23, 2011; and Jay Solomon, “U.S. Reacts to Fear of Iran’s Rising Clout,” Wall Street Journal, March 22, 2011, p. 6. 2 See, for example...role of ideology among Israel’s political elite, see Asher Arian, Poli- tics in Israel: The Second Republic, Washington, D.C.: CQ Press, 2005. 43 Halevi...www.haaretz.com/print-edition/opinion/growing-mideast-democracy- could-benefit-israel-too-1.354143 Arian, Asher , Politics in Israel: The Second Republic

  5. Resource Rivalry in the Third World,

    Science.gov (United States)

    1984-03-31

    MXexico, Peru, and lesser amounts in Bolivia and Chile ); 17 % of tin (mainly Bolivia); 18 of beryllitn (Brazil), and less significant amounts of some...second largest supplier (after Car.ada) of gold and third largest source (after South Africa and Chile ) of36 vanadium. In the overall picture of the...Scientific, r Economic, Political Asnects: An Interdisciplinary Manual. -! sida ,Malta: Inter-ational Ocean Institute, 1981. See also International Ccean

  6. Cirurgia de catarata: características e opiniões de pacientes com visão mono versus binocular

    Directory of Open Access Journals (Sweden)

    Roberta Ferrari Marback

    2010-10-01

    Full Text Available OBJETIVO: Verificar em dois grupos de pacientes com visão monocular (grupo 1 e com visão binocular (grupo 2, a serem submetidos à cirurgia de catarata num hospital universitário, opiniões em relação ao problema ocular, à qualidade da visão e à cirurgia de catarata. MÉTODOS: Foi realizado estudo transversal e comparativo, de forma consecutiva, por meio de questionário estruturado, aplicado por entrevista a pacientes, elaborado a partir de estudo exploratório e medidas acuidade visual e causa da perda visual. RESULTADOS: A amostra foi constituída por 96 indivíduos do grupo 1 (50,0% homens; 50,0% mulheres, com idade entre 41 e 91 anos, média 69,3 anos ± 10,4 anos e 110, do grupo 2 (40,9% homens; 59,1% mulheres, com idade entre 40 e 89 anos, média 68,2 anos ± 10,2 anos. A maioria dos indivíduos de ambos os grupos apresentava baixa escolaridade. Não houve diferença estatisticamente significante entre os grupos em relação ao sexo (p=0,191, à idade (p=0,702 e à escolaridade (p=0,245. Não exerciam atividade laboral 95,8% dos indivíduos do grupo 1 e 83,6%, do grupo 2 (p=0,005 e 30,4% do grupo 1 mencionaram não ter possibilidade de trabalhar por causa da deficiência visual. Observou-se acuidade visual do olho a ser operado menor que 0,05 em 40,6% (grupo 1 e 33,6% (grupo 2, entre 0,25 e 0,05. Quase a totalidade dos indivíduos de ambos os grupos afirmou ter dificuldade para realização das atividades de vida diária e qualificou como insuficiente a respectiva acuidade visual; 71,9% dos entrevistados do grupo 1 e 71,6%, do grupo 2 mencionaram saber a causa da visão fraca; desses, 87,1% do grupo 1 e 83,3% do grupo 2 referiram a catarata como causa da baixa acuidade visual. CONCLUSÃO: Os indivíduos de ambos os grupos tiveram acesso à cirurgia de catarata com acuidade visual menor do que a idealmente indicada; os pacientes com visão monocular apresentaram acuidade visual significativamente menor em relação aos com vis

  7. Postnatal expression and distribution of Refsum disease gene associated protein in the rat retina and visual cortex: effect of binocular visual deprivation.

    Science.gov (United States)

    Ahn, Kyu Youn; Nam, Kwang Il; Kim, Baik Yoon; Cho, Chul Woong; Jeong, Sang Ki; Yang, Kun Jin; Kim, Kyung Keun

    2002-04-01

    Previously, phytanoyl-CoA alpha-hydroxylase-associated protein 1 (PAHX-AP1) was isolated as a novel neuron-specific protein to interact with Refsum disease (RfD) gene PAHX. Its expression in the brain increased after eyelid opening, and the elevated level was maintained through adulthood. In this report, to verify the hypothesis that light could trigger this increase, we have examined the developmental distribution pattern of PAHX-AP1 in rat retina and visual cortex, and changes of its expression by binocular deprivation. Northern blot analyses demonstrated PAHX-AP1 expression reached its highest level in the visual cortex and eyeball at 4 weeks after birth, and these levels were maintained through adult life. Two weeks after visual deprivation, its expression in the eyeball and visual cortex decreased compared with the control. In situ hybridization analyses of the retina showed that PAHX-AP1 expression was limited to the ganglionic cell layer at 10 days after birth, but expressed in the inner nuclear cell layer and extended to the outer nuclear cell layer at 2 and 3 weeks after birth, respectively. Two weeks after visual deprivation, however, it decreased in the ganglionic and inner nuclear cell layer, and disappeared in the rod and cone cell layers. In the visual cortex, strong signals of PAHX-AP1 were detected in layers IV and VI, and II-VI at 10 days and 2 weeks after birth, respectively. Its expression decreased after 2 weeks of visual deprivation. These results indicate that visual stimulation is essential for the maintenance of PAHX-AP1 expressions in the retina, especially in the rod and cone cell layers, and visual cortex, and suggest that PAHX-AP1 may be involved in the developmental regulation of the photoreceptor's function.

  8. 基于双目视觉的无人引导运输装置的研究%Research on Automated Guided Vehicle Based on Binocular Vision

    Institute of Scientific and Technical Information of China (English)

    吴年祥; 吴卫东

    2015-01-01

    针对路径单一、路径变化需重复施工,柔性和智能化程度不足的传统式无人引导运输装置,研究出基于高射频识别、磁条导向与双目视觉导航结合技术、路径规划技术、区域匹配的算法等基础上的无人引导运输装置。协助人工完成货物的登记,入库以及运输,具有精确朝向与完整定位、磁条和视觉校正的循迹和导航、货物追踪管理、智能任务分配和路径规划、目标跟踪等功能。广泛应用于机械、汽车、电子等诸多智能工厂领域,减少人力成本。%An unmanned guided transport is developed based on high frequency identification,magnetic orien-tation and navigation based on binocular vision technology,path planning technology,region matching algorithm and so on are aimed at traditional AGV(Automated Guided Vehicle)that single path,path changes need to repeat construction ,Lack of flexibility and intelligence .The AGV assit artificial complete the registration,storage and transportation of goods,with accurate orientation,and complete positioning,tracking and navigation of magnetic stripe and visual correction,cargo tracking management,smart task assignment and path planning,target tracking, and other functions.AGV is widely used in machinery,automobile,electronics and many other fields of intelligent plant reduce the manpower cost.

  9. Person following of binocular robot by extracting multiple features%多特征提取的双目机器人目标跟踪

    Institute of Scientific and Technical Information of China (English)

    王丽佳; 贾松敏; 李秀智; 王爽

    2013-01-01

    为了解决复杂环境下双目机器人的目标跟踪问题,提出多特征提取的方法。在机器人静止-目标运动模式下根据改进的步态光流图和视角识别目标并构造颜色直方图模板;在机器人运动-目标运动模式下利用扩展卡尔曼滤波器、基于自适应核函数的CamShift算法、基于Hu矩的头肩模型匹配算法提取目标的运动特征、颜色特征和头肩特征以实现目标跟踪。实验分析表明,所提出方法能够避免启动时手动框选目标,可以实现遮挡和背景与目标相似度高等复杂环境下的目标跟踪。%To solve the person following problem of binocular robot in complex environment, a method of extracting multi-feature is presented. For the stationary robot and moving target, the improved gait flow image and view are adopted to recognize the target, and then the color template is constructed. For both the moving robot and target, the motion information of the head and shoulder model and the color feature extracted by extended Kalman filter(EKF), the Hu moment based head and shoulder model matching method and the adaptive kernel based CamShift algorithm are used to track the target. The experiments show that this method avoids selecting the person manually, and tracks the person effectively in complex environment, such as backgroud and target high similarity, occlusion and so on.

  10. Effect of binocular vision in myopia and hyperopia amblyopia%近视性和远视性弱视视功能发育临床观察

    Institute of Scientific and Technical Information of China (English)

    鲁诚; 魏盟; 魏承丽; 任静

    2015-01-01

    目的::了解近视性弱视和远视性弱视对双眼视功能发育的影响。方法:对50例经治疗后双眼矫正视力均达0.9以上的弱视患儿行双眼视功能检查。测量同时视、融合范围及远近立体视。根据患儿的屈光状态将患儿分为A组(近视组)20例、B组(远视组)30例。比较A、B两组同时视、融合和立体视差异。结果:近视组中存在同时视的15例(75%),集合融合范围正常的6例(30%),分开融合范围正常的16例(80%),有正常远立体视的7例(35%),有正常近立体视的6例(30%)。远视组中存在同时视的26例(87%),集合融合范围正常的7例(23%),分开融合范围正常的20例(67%),有正常远立体视的15例(50%),有正常近立体视的7例(23%)。50例患儿中存在正常远立体视的为22例(44%),正常近立体视13例(26%)。同时视在两组患儿之间的差异无统计学意义(χ2=0.454,P>0.05);集合性融合和分开性融合在两组患儿之间的差异也无统计学意义(χ2=0.565,P>0.05;χ2=0.740,P>0.05);远近立体视两组患儿差异也均无统计学意义(χ2=0.195,P>0.05;χ2=0.295, P>0.05)。结论:近视及远视因素对弱视患儿双眼视功能发育影响的差异不显著。弱视治疗后矫正视力正常的患儿短期内双眼视功能仍未完全恢复正常。%AlM:To investigate the visual function in myopia and hyperopia amblyopia whose corrected visual acuity have recovered to normal.METHODS: The visual function of children ( 50 cases ) with amblyopia eyes by binocular vision correction after treatment above 0. 9 was checked. The simultaneous perception, fusion range and distance stereopsis were measured. According to the refractive condition of the children who were divided into group A ( myopia, 20 cases ) and group B ( hyperopia, 30 cases ) . The statistically difference of simultaneous perception, fusion function and stereopsis in two groups was analyzed. RESULTS: Fifteen ( 75

  11. Observation of binocular vision after surgical corrections in V - pattern exotropia children%儿童V型外斜视手术前后双眼视觉功能变化观察

    Institute of Scientific and Technical Information of China (English)

    谢小华; 吕露; 戴鸿斌; 李祥芸; 石明华

    2015-01-01

    AlM:To observe the changes of binocular vision in V-pattern exotropia children before and after surgical correction, and the effect of training in reconstructing the binocular vision after surgical corrections.METHODS: Sixty V-pattern exotropia children were enrolled in this study and were divided into three groups according to their age:group A (4~6 years old), group B (7~9 years old), and group C (10~12 years old), 20 cases for each group. Patients received routine refraction and ophthalmic examinations. Distance and near deviation were measured by prism-covering method and synoptophore. The simultaneous perception and fusion were examined with a synoptophore, and the stereacuity was measured with stereograms ( Titmus) . The children who didn’t reconstruct binocular vision function 1wk after surgery received binocular vision training. The data were recorded before and 1 , 2, 4, and 8wk after surgery. RESULTS: Binocular vision significantly improved among the children after surgery in group A and B ( P0. 05). CONCLUSlON: V - pattern exotropia children can benefit from early surgical correction and training after surgery in reconstruct binocular vision.%目的::观察不同年龄组儿童V型外斜视手术前后双眼视觉功能变化及术后双眼视觉训练对术后双眼视觉建立的影响。方法:收集60例4~12岁V型外斜视患儿,按接受手术年龄分为三组:A组(4~6岁)、B组(7~9岁)、C组(10~12岁),每组20例。采用三棱镜加遮盖法及同视机检查33 cm及6 m处正前方及向上、向下注视的斜视度,以三棱镜度记录。同视机检查同时视、融合视,Titmus立体视图检查近立体视。对术后1 wk未能建立同时视功能的患儿给予双眼视觉训练,术后1,2,4,8 wk随访。结果:A、B 组手术前、后双眼视觉功能有明显差异(P0.05)。结论:早期手术矫正眼位正位,及术后积极有效的双眼视觉训练对于 V 型外斜视患者术后立体视的重建十分有利。

  12. 间歇性外斜视手术前后双眼视功能的临床观察%Clinical observation on preopterative and postoperative binocular vision of children with intermittent exotropia

    Institute of Scientific and Technical Information of China (English)

    黄蔚茹; 马琳; 张鑫

    2012-01-01

    目的 观察间歇性外斜视手术后双眼单视功能的变化情况.方法 对84例间歇性外斜视患儿分为有双眼视功能组(43例)和无双眼视功能组(41例),根据斜视度行斜视矫正手术,手术前后分别检测Ⅰ级视功能、Ⅱ级视功能和Ⅲ级视功能(Titmus立体视觉图).对手术前后的结果进行统计学分析.结果 84例患儿中,手术前有Ⅰ级视功能者41例,占48.80%;手术后有Ⅰ级视功能65例,占77.38%,两者比较差异有统计学意义(P<0.05).术前具有Ⅱ级视功能者27例,占32.14%;手术后增加至65例,占77.38%,两者比较差异有统计学意义(P<0.05).Ⅲ级视功能(Titmus立体视觉图)检测到有41例患儿手术前有不同程度的立体视,占48.80%;术后增加至68例,占80.95%,差异均有统计学意义(P< 0.05).结论 手术治疗有助于间歇性外斜视患儿双眼视功能的重建.%Objective To observe the change of binocular vision of patients with intermittent exotropia after surgery.Methods Binocular single vision of patients were 43 cases,no binocular vision of patients were 41 cases.Binocular single vision of both distance and near was checked in one hundred and sixty eight patients with intermittent exotropia before and after surgery.Results There were 41 patients (48.80% ) with preoperative near stereopsis before surgery,65 patients(77.38% ) with near stereopsis postoperative after surgery.There was significant difference between before surgery and after surgery (P < 0.05 ).Rbuilding rate of near stereopsis after surgery was 80.95%,and there were 68 patients of near stereopsis after surgery.The results of the recovery of binocular vision postoperatively was as well as the stereopsis.Conclusions Surgical treatment of intermittent exotropia is very important for the reconstruction of binocular vision.

  13. Fast and Automatic Railway Building Structure Clearance Detection Technique Based on Mobile Binocular Stereo Vision%基于移动双目视觉的铁路建筑物限界快速自动检测方法

    Institute of Scientific and Technical Information of China (English)

    胡庆武; 陈智勇; 吴莎

    2012-01-01

    采用高速、高分辨率CCD相机以优于10-6s时间同步精度获取铁路建筑物限界的移动双目立体图像.提出了基于移动双目视觉测量模型,通过自检校多传感器系统标定和DGPS/IMU集成处理计算各双目图像严密的内、外方位元素,构建立体图像中各要素的空间相对关系.提出基于自动拟合计算的线路中心线空间位置的建筑物限界计算模型,与车辆限界相结合计算建筑物限界参数.设计并开发了一个基于双目视觉的铁路建筑物限界自动检测试验系统,进行铁路建筑物限界自动检测试验,对其精度进行分析和讨论,结果表明可达到标准规定的技术指标.%The synchronization imaging technique with high speed and high resolution CCD cameras is presented to obtain the mobile binocular stereo image of the clearances of railway building structures. With the unit timing board, the binocular images can obtain synchronized time to GPS/IMU sensors less than 10~6s. The photo-grammetry surveying model based on mobile binocular vision is proposed. With the sensor calibration parameters based on self-calibration and the train position and attitude from DGPS/IMU integration, all the objects in the stereo images can be restricted within a precise formulation. The intelligent image processing algorithm is designed to automatically extract railway from the binocular sequence images to calculate the railway center-line. The railway building structure clearance calculation model with the railway centerline is presented to calculate the building constructure clearance parameters within the railway clearance standards. The experiment system of railway building structure clearances is designed with the proposed methodology for project applications. The accuracy of building structure clearance detection is less than 0. 03m which satisfies the railway clearance measurement standards.

  14. Perceptual incongruence influences bistability and cortical activation.

    Directory of Open Access Journals (Sweden)

    Gijs Joost Brouwer

    Full Text Available We employed a parametric psychophysical design in combination with functional imaging to examine the influence of metric changes in perceptual incongruence on perceptual alternation rates and cortical responses. Subjects viewed a bistable stimulus defined by incongruent depth cues; bistability resulted from incongruence between binocular disparity and monocular perspective cues that specify different slants (slant rivalry. Psychophysical results revealed that perceptual alternation rates were positively correlated with the degree of perceived incongruence. Functional imaging revealed systematic increases in activity that paralleled the psychophysical results within anterior intraparietal sulcus, prior to the onset of perceptual alternations. We suggest that this cortical activity predicts the frequency of subsequent alternations, implying a putative causal role for these areas in initiating bistable perception. In contrast, areas implicated in form and depth processing (LOC and V3A were sensitive to the degree of slant, but failed to show increases in activity when these cues were in conflict.

  15. 3D Reconstruction of Desktop of Table Tennis Based on the Binocular Vision%双目视觉的台球桌面的三维重构

    Institute of Scientific and Technical Information of China (English)

    张旭飞; 王朝立; 袁伟

    2013-01-01

    At present, with the rapid development of the computer technologies which has grown dramatically, and there are more and more sports competition where some high and new technologies are emploited as the electronic referee to assist referee to do the decisions, in order to achieve the spirit of fair play which respected by Olympic. During this process, the camera plays an important role in computer vision. 3D reconstruction is a process based on a single view or multi-view images to obtain the 3D information in the field of computer vision. In this paper, in order to complete a task about three-dimensional reconstruction of desktop of Table tennis, we take 3D reconstruction technologies in computer vision as the mainly research object, including specific details about the theoretical knowledge on the binocular vision and the reconstruction algorithm provided by the computer vision library OpenCV. The 3D reconstruction of billiards desktop have strong practical significance, which laid a good foundation for the electronic referee to work in the billiards competition.%  随着计算机技术的迅猛发展,在越来越多的体育比赛中纷纷出现了电子裁判来辅助裁判进行判罚工作,以实现奥林匹克的公平竞赛精神。而在实现这种数字化裁判的过程中,摄像机在计算机视觉中起着重要的作用,三维重构就是根据单视图或者多视图的图像重建三维信息的过程。主要以计算机视觉中的三维重构技术作为研究对象,具体详述了有关双目视觉的一些理论知识,充分利用计算机视觉库OpenCV提供的重建算法,来完成对台球桌面的三维重构工作。台球桌面的三维重构具有很强的现实意义,为电子裁判进入桌球比赛打下了良好的基础。

  16. 双眼视训练治疗弱视的临床效果%Clinical effect of binocular vision training for amblyopia

    Institute of Scientific and Technical Information of China (English)

    王莉; 李春林

    2015-01-01

    目的:本研究旨在探讨双眼视功能综合功能训练疗法对于儿童弱视的治疗效果。方法:将本院眼科中心收治的78例(144眼)弱视儿童根据就诊顺序分为研究组39例(74眼)和对照组39例(70眼),对照组采用屈光不正矫正、遮盖疗法、光栅刺激、红光闪烁、视标训练治疗,研究组在此基础上加用同视机、网络版多媒体训练系统进行双眼视功能训练治疗,观察两组儿童在治疗3个疗程(30 d为1个疗程)后的视功能变化情况。结果:研究组轻度弱视儿童的治疗有效率96.97%、中度弱视儿童治疗有效率88.46%、研究组的总有效率86.49%分别显著的高于对照组的75.76%、56.52%、61.43%(P0.05)。治疗后研究组的立体视正常率78.38%显著的高于对照组的60.00%(P0.05). Atfer treatment, the study group of stereopsis normal rate of 78.38% was signiifcantly higher than that of the control group of 60.00% (P<0.05); atfer treatment study group and the control group of stereopsis of normal rate compared with those before treatment were significantly increased (P<0.05).Conclusion:Binocular visual functional training can improve the visual function of children.

  17. The study of re-establishment of binocular vision and the impact factors in adults after exotropia surgery%成人外斜视术后双眼视觉重建及其影响因素

    Institute of Scientific and Technical Information of China (English)

    徐翠翠; 万鲁芹; 张静; 宫华青

    2016-01-01

    Objective To study the restoration of binocular vision and the factors that impact adults after exotropia surgery.Methods Fifty-four adult patients with exotropia were divided into two groups,based on age of onset:before visual maturity (BVM,<9 years old) or after visual maturity (AVM,≥9 years old).Binocular vision,both distance and near,was checked before surgery and 6 weeks after surgery with a synoptophore and Yan's digital stereogram.Results The restoration rate of distance binocular vision was as follows:For grade Ⅰ binocular vision,the rate was 77% in the AVM group,which was significantly higher than the rate for the BVM group (33%;x2=10.240,P<0.01).For grade Ⅱ,the rate was the same as for grade Ⅰ.For grade Ⅲ,the rate was 47% in the AVM group and was 17% in the BVM group.Differences between the two groups were statistically significant (x2=5.400,P<0.05).The restoration rate of near binocular vision was 73% in the AVM group,which was significantly higher than that for the BVM group (29%;x2=10.461,P<0.01).Logistic analysis showed that the age of onset and the age at the time of surgery are the important factors affecting the restoration of postoperative distance (OR=6.046,P<0.05;OR=0.140,P<0.01) and near stereopsis (OR=10.825,P<0.05;OR=0.189,P<0.05).The type of exotropia and the degree of the preoperative strabismus had no marked influences on binocular vision.Conclusion Surgical correction of adult exotropia is helpful in the restoration of binocular visual functions and beneficial to obtaining a certain degree of stereopsis.The restoration of distance stereopsis is associated with the age of onset and the age at the time of surgery.The age of onset played a key role in obtaining stereopsis.In order to improve postoperative binocular vision,surgery should be performed as early as possible for adult exotropia patients.%目的 探讨成人外斜视术后双眼视觉重建及其影响因素.方法 回顾性病例研究.收

  18. Dynamic Obstacle Avoidance Based on Binocular Vision for AS-R Mobile Robots%AS-R 移动机器人基于双目视觉的动态避障

    Institute of Scientific and Technical Information of China (English)

    张寒; 张冰蔚

    2016-01-01

    针对移动机器人的动态避障问题,以AS-R移动机器人为平台,设计了一种基于双目视觉的动态避障方法。从双目视觉系统出发,介绍了AS-R机器人的视觉系统,研究了AS-R机器人的运动原理,探讨了图像信息处理的过程;最后设计了两种简单环境下机器人的动态避障,并验证了所提方法的有效性。%Aiming at the problem of obstacle avoidance for mobile robot ,with the platform of AS-R mobile robot ,a novel approach based on binocular vision for dynamic obstacle avoidance was put forward .Starting from binocular vision system ,the paper intro-duced the AS-R robot vision system ,studied the principles of AS-R robot movement ,and discussed the processing of image informa-tion .Experiments based on both simulation platform and ASR robot verified the effectiveness of the proposed approach .

  19. Vehicle Reversing Obstacle Measurement Based on Binocular-camera Stereo Vision%基于双目立体视觉的倒车环境障碍物测量方法

    Institute of Scientific and Technical Information of China (English)

    刘昱岗; 王卓君; 王福景; 张祖涛; 徐宏

    2016-01-01

    It is one of the important urban traffic hidden troubles that accidents caused by driver reversing. In order to solve the shortcomings of traditional vehicle reversing technology based on machine vision, such as image distortions and low accuracy of distance perception, a vehicle reversing obstacle detection and measurement is presented based on binocular-camera stereo vision. The internal and the external parameters can be obtained according to the binocular calibration theory, which can be used to analyze the condition of the camera distortion. Then, calibration parameters are used to correct the binocular image. A method named epipolar constraint is used to get a pair of images coplanar. After this, the actual coordinates of each object in the image can be acquired through parallax of binocular image and the triangulation principle. Finally, the effectiveness of the obstacle measurement based on binocular camera stereo vision is verified by calculating the error between the measured distance and the actual distance, which is accomplished through fixing a single object. The experimental results show that the camera x-coordinate value is almost consistent with the actual results. Stereo rectification removes distortions and turning the stereo pair of images into standard aligned form which are nearly coplanar. The method can detect the rear obstacles effectively, and improve the ability to reverse the environmental awareness. Besides, it can improve the safety performance of the reversing process.%倒车引发的交通事故是主要的城市交通安全隐患之一,本文针对倒车安全及障碍物检测中传统机器视觉倒车图像存在失真,以及距离感知精度低的问题,提出了一种基于双目立体视觉的倒车环境障碍物测量方法。首先根据双目标定理论获取摄像头内、外参数并分析摄像头畸变情况,使用标定参数对双目图像进行校正,运用极线约束使双目图像平行共面,通

  20. 小儿内斜视矫正术后双眼单视功能的建立%Establishment of binocular single vision after surgical correction of eye position in infantile esotropia

    Institute of Scientific and Technical Information of China (English)

    王亚明

    2015-01-01

    目的:探讨小儿内斜视矫正术后双眼单视功能的建立情况及其影响因素。方法采用手电筒式Worth四点灯和Titmus立体视图测定小儿内斜视矫正术216例的中心融合、周边融合及立体视锐度。利用Logistic回归分析双眼单视功能建立的影响因素。结果术后获得周边融合者占62.5%;获得中心融合者占6.02%;获得不同程度的立体视者占50.5%。术后双眼单视功能明显升高,双眼单视功能与各变量密切相关:病程(β=1.511,P=0.04)、术前斜视度(β=1.734,P=0.03)与术后双眼单视功能的建立呈正相关;与手术年龄(β=-0.85,P=0.01)、弱视治疗时间(β=-0.24,P=0.03)以及术后斜视度(β=-1.41,P=0.02)呈负相关。结论内斜视小儿应尽早手术,治疗时间越早及斜视度越小者,术后越容易建立周边融合。先天性内斜视建立周边融合的程度较非调节性内斜视及部分调节性内斜视者更难。%Objective To investigate the establishment of binocular vision and its influencing factors after surgical correction of pediatric esotropia. Methods Two hundred and sixteen cases of children who underwent esotropia surgery were measured. The center fusion, peripheral fusion and stereopsis were recorded by using torch-style lighting and Titmus Worth four dimensional view of assessment. The influencing factors of establishment of binocular vision were analysed by logistic regression analysis. Results Patients who achieved peripheral fusion after surgery accounted for 62. 5% (135/216), achieved centers fusion accounted for 6. 02% (13/216), and achieved stereopsis with varying degrees accounted for 50. 5% (109/216). Binocular vision after surgery was significantly improved, and it was closely related with the following variable:Disease duration (β=1. 51, P=0. 04) and preoperative strabismus (β=1. 734, P=0. 03) were positively correlated with establishment of postoperative binocular vision function. The establishment of

  1. Clinical analysis and treatment of 5 cases of nonstrabmistic binocular vision abnormalities%非斜视性双眼视觉异常临床分析

    Institute of Scientific and Technical Information of China (English)

    艾丽珍

    2014-01-01

    Objective To analyze the test results of abnormal visual function of 5 cases of nonstrabmistic binocular vision.Methods Based on the general optometry,using Von Graefe method the phoria of direction and scope in the distance,convergence magnitude,AC/A ratio,Risley prism measurement of distance with variable levels of positive and negative fusional vergence,positive and negative fusional vergence,amplitude of convergence and state of feeling with Worth4 lighting and RDS stereo vision chart were measured.Refer Morgan analysis method to analyze and take appropriate visual training.Results (1) The feature of convergence insufficiency was distance phoria normal,and closed high exophoria and low positive relative convergence (PRC) in near distance,AC/A low.(2) Esophoria for near,far from normal and low negative relative convergence (NRC) in convergence excess.high AC/A.(3) Divergence excess that was distance high exophoria,near phoria normal and high AC/A.(4) The feature of fusional vergence diminution was far and near distance phoria normal,AC/A normal,near point of convergence (NPC) of distal movement.(5) Simple esophoria was distance esophoria near phoria beyond the normal range,AC/A normal.Conclusions The 5 cases belong to the nonstrabmistic binocular vision anomalies and their clinical symptoms are similar,however,inspection results are different,the diagnosis and treatment are also different.%目的 对5例不同的非斜视性双眼视觉异常的视功能检测结果进行综合分析.方法 对2012年4月至2013年4月在南昌大学附属眼科医院在验光基础上,应用综合验光仪测量集合幅度、调节幅度以及正负相对调节,用Von Graefe法测量在远近距离的隐斜方向和隐斜度、调节集合/调节值(AC/A)比率(调节性集合与调节量之比),用Risley可变棱镜测量远近水平正负融像聚散,用Worth4点灯和R.D.S立体视觉图测量立体视觉.参照Morgan分析法加以分析并

  2. 屈光参差性弱视儿童治愈后的双眼视觉研究%Binocular vision in cured anisometropic amblyopia

    Institute of Scientific and Technical Information of China (English)

    林楠; 王京辉; 孙省利; 董芳

    2012-01-01

    Objective To investigate the binocular vision change in cured anisometropic amblyopic children and normal children. Design Retrospective case series. Participants 74 children with anisometropic amblyopia and 74 normal children. Methods Binocular vision of 74 anisometropic amblyopic children with best distance acuity ≥0.9 and 74 normal children were tested with synoptophore and stereogram designed by Yan Shao-ming. Main Outcome Measures Simultaneous perception, distance fusion range, distance qualitative stereopsis and near zero disparity. Results (1) Distance qualitative stereopsis in cured anisometropic amblyopic children was worse than normal children(χ2=11.331 ,P=0.001), simultaneous perception (χ2=1.855 ,P=0.173) and distance fusion range (χ2=1.012,P= 0.603) had little difference between them. (2) Near zero disparity in cured anisometropic amblyopic children was obviously worse than normal children (χ2=27.759,P=0.000). (3) The milder the degree of anisometropic amblyopia, the more prominent the improvement of the near zero disparity (χ2=17.116,P=0.009). While simultaneous perception (x2=0.879,P=0.644),distance fusion range(χ2=7.930,P= 0.094), distance qualitative stereopsis (χ2=2.854, P=0.240) had little difference. Conclusion Anisometropic amblyopia affects the development of stereoacuity critically. The stereoacuity of anisometropic amblyopic children with best distance acuity ≥0.9 after treatment is still worse than normal children. The more severe the degree of anisometropic amblyopia, the more prominent the effect of the near zero disparity.%目的 了解屈光参差性弱视儿童治愈后双眼视觉状况.设计回顾性病例系列.研究对象屈光参差性弱视儿童74例,正常儿童74例.方法 采用同视机和颜少明《立体视觉检查图》对74例经治疗矫正视力已≥0.9的屈光参差性弱视儿童和74例正常儿童的双眼视觉功能进行检测.主要指标同时知觉、远融合范围、定性

  3. Visibility of monocular symbology in transparent head-mounted display applications

    Science.gov (United States)

    Winterbottom, M.; Patterson, R.; Pierce, B.; Gaska, J.; Hadley, S.

    2015-05-01

    With increased reliance on head-mounted displays (HMDs), such as the Joint Helmet Mounted Cueing System and F-35 Helmet Mounted Display System, research concerning visual performance has also increased in importance. Although monocular HMDs have been used successfully for many years, a number of authors have reported significant problems with their use. Certain problems have been attributed to binocular rivalry when differing imagery is presented to the two eyes. With binocular rivalry, the visibility of the images in the two eyes fluctuates, with one eye's view becoming dominant, and thus visible, while the other eye's view is suppressed, which alternates over time. Rivalry is almost certainly created when viewing an occluding monocular HMD. For semi-transparent monocular HMDs, however, much of the scene is binocularly fused, with additional imagery superimposed in one eye. Binocular fusion is thought to prevent rivalry. The present study was designed to investigate differences in visibility between monocularly and binocularly presented symbology at varying levels of contrast and while viewing simulated flight over terrain at various speeds. Visibility was estimated by measuring the presentation time required to identify a test probe (tumbling E) embedded within other static symbology. Results indicated that there were large individual differences, but that performance decreased with decreased test probe contrast under monocular viewing relative to binocular viewing conditions. Rivalry suppression may reduce visibility of semi-transparent monocular HMD imagery. However, factors, such as contrast sensitivity, masking, and conditions such as monofixation, will be important to examine in future research concerning visibility of HMD imagery.

  4. Viewing the Constellations with Binoculars

    CERN Document Server

    Kambic, Bojan

    2010-01-01

    A guide to practical astronomy. It introduces the reader to some basic (and some not-so-basic) astronomical concepts, and discusses the stars and their evolution, the planets, nebulae, and distant galaxies

  5. Heat reveals faults

    Energy Technology Data Exchange (ETDEWEB)

    Weinreich, Bernhard [Solarschmiede GmbH, Muenchen (Germany). Engineering Dept.

    2010-07-01

    Gremlins cannot hide from the all-revealing view of a thermographic camera, whereby it makes no difference whether it is a roof-mounted system or a megawatt-sized farm. Just as diverse are the range of faults that, with the growing level of expertise, can now be detected and differentiated with even greater detail. (orig.)

  6. Comparison and evaluation of the surgical effect and binocular vision change before and after surgery for intermittent exotropia%双眼视觉在间歇性外斜视手术前后变化及手术效果相关研究

    Institute of Scientific and Technical Information of China (English)

    华文娟; 顾永辉; 徐丹丹

    2015-01-01

    AIM: To investigate the preoperative binocular visual function of intermittent exotropia and the rebuilding and recovery of the postoperative binocular visual function, and analyze the effect of binocular visual function on orthophoria after surgery. METHODS:From January 2011 to January 2014, 47 basic intermittent exotropia patients caming for treatment were collected in the clinical data. The changes in their near stereopsis, binocular visual function, binocular fusion and distance stereopsis after operations were recorded in the form of data. The preoperative binocular vision and the postoperative rebuilding were analyzed and contrasted with each other. In addition, the effect on the postoperative maintaining of orthophoria due to the existence, recovery and rebuilding of binocular visual function were observed. RESULTS:Intermittent exotropia patients got damage in different levels on their binocular visual functions, especially on distance stereopsis, which was the heaviest and earliest. After the operation, all functions were obviously recovered and reconstructed and the improvements were statistically significant compared against those before the operation (P CONCLUSION: The intermittent exotropia cause damage to the stereopsis which happened the earliest. Obvious recovery and reconstruction of binocular visual function can be observed after the surgery. A relatively good preoperative binocular visual function may lead to the increase in the ratio of orthophoria or cure the intermittent exotropia. Performing an operation when distance stereopsis is damaged can increase the success rate for the surgery and reduce the recurrence rate.%目的:观察间歇性外斜视术前双眼视功能状态和术后双眼视功能的重建与恢复,分析双眼视功能对术后眼位正位的影响。  方法:收集我院2011-01/2014-01收治的47例基本型间歇性外斜视患者的临床资料,记录术前术后近立体视、双眼同时视、融合功能及

  7. 基于OpenCV的双目立体视觉监控跟踪系统%A Binocular Stereo Vision Surveillance Tracking System which Based on Computer Vision Library OpenCV

    Institute of Scientific and Technical Information of China (English)

    万智萍; 叶仕通

    2013-01-01

    Monitoring equipment of the present stage cannot independently obtain the distance information of the target region, and when it is at outside of a certain range, which due to a deeper level of image blur can not identify a specific individual.For the above problems, designing and development of a binocular stereo vision surveillance tracking system which based on computer vision library OpenCV, and combined with self-developed to binocular stereovision ranging Improvement Act and contour search method, which distance measurements and contour recognition can be achieved on the objects within the monitored region.Experimental results show that based binocular stereo vision OpenCV monitoring tracking system is reliable and stable, within a certain range which can to achieve the experimental requirements.%现阶段的监控设备无法自主获取目标区域的距离信息,而且在一定范围之外,由于图像模糊程度加深而无法对特定个体进行识别确认.针对以上存在的问题,设计并开发了基于计算机视觉库OpenCV(IntelOpen Source Computer Vision Library)的双目立体视觉监控跟踪系统.利用OpenCV强大的计算机视觉和图像处理能力,结合自行研究的双目立体视觉测距改进法和轮廓搜索法,能实现对监控区域内的物体进行距离测量和轮廓识别.通过实验结果表明,基于OpenCV的双目立体视觉监控跟踪系统运行可靠稳定,在一定范围内达到了实验要求.

  8. Brain networks underlying bistable perception.

    Science.gov (United States)

    Baker, Daniel H; Karapanagiotidis, Theodoros; Coggan, David D; Wailes-Newson, Kirstie; Smallwood, Jonathan

    2015-10-01

    Bistable stimuli, such as the Necker Cube, demonstrate that experience can change in the absence of changes in the environment. Such phenomena can be used to assess stimulus-independent aspects of conscious experience. The current study used resting state functional magnetic resonance imaging (rs-fMRI) to index stimulus-independent changes in neural activity to understand the neural architecture that determines dominance durations during bistable perception (using binocular rivalry and Necker cube stimuli). Anterior regions of the Superior Parietal Lobule (SPL) exhibited robust connectivity with regions of primary sensorimotor cortex. The strength of this region's connectivity with the striatum predicted shorter dominance durations during binocular rivalry, whereas its connectivity to pre-motor cortex predicted longer dominance durations for the Necker Cube. Posterior regions of the SPL, on the other hand, were coupled to associative cortex in the temporal and frontal lobes. The posterior SPL's connectivity to the temporal lobe predicted longer dominance during binocular rivalry. In conjunction with prior work, these data suggest that the anterior SPL contributes to perceptual rivalry through the inhibition of incongruent bottom up information, whereas the posterior SPL influences rivalry by supporting the current interpretation of a bistable stimulus. Our data suggests that the functional connectivity of the SPL with regions of sensory, motor, and associative cortex allows it to regulate the interpretation of the environment that forms the focus of conscious attention at a specific moment in time.

  9. Negative “gossip” stimuli modulate left-lateralized P1 component while viewing neutral faces

    DEFF Research Database (Denmark)

    Weed, Ethan; Allen, Micah Galen; Gramm, Daniel

    Language allows us to operate more efficiently in the world. By hearing about others’ experiences, we are able to orient toward things that could be beneficial to us, and avoid hazards. This sharing of experiences is particularly prominent in the social realm. Using a binocular rivalry paradigm, ...

  10. New progress in the treatment of amblyopia and related binocular visual impairment%弱视及弱视相关双眼视功能损害治疗的新进展

    Institute of Scientific and Technical Information of China (English)

    李蕾; 付晶

    2016-01-01

    人眼在视觉发育期由于单眼斜视、未矫正的屈光参差、高度屈光不正及形觉剥夺引起的单眼或双眼最佳矫正视力低于相应年龄的视力为弱视;或双眼视力相差2行及以上,视力较低眼为弱视。弱视在视觉敏感期给予正确治疗可治愈,然而一旦错过治疗时机则会造成终生视力低下;且弱视还会影响双眼视觉功能。因此,弱视的治疗一直是眼科研究的热点问题。目前,弱视的主要方法包括屈光矫正、遮盖疗法、药物治疗、压抑疗法、手术治疗(针对形觉剥夺性弱视)、综合治疗等。近年来,双眼视功能的重建在弱视治疗评价中也逐渐受到重视。本文中笔者在回顾国内外相关文献的基础上,对弱视的治疗方法及最新进展做一综述。%The best corrected visual acuity of monocular or binocular vision in patients with amblyopia is lower than that in normal eyes .It is in visual development period ,as a result of the monocular strabismus,uncorrected anisometropia, highly refractive errors, form deprivation induced.In addition, binocular vision is a difference of 2 lines, low vision eye is amblyopia .Amblyopia in the visual sensitive period to give the correct treatment can be cured , but once missed the opportunity of treatment will cause lifelong amblyopia;and the amblyopia will affect the binocular visual function .Therefore , the treatment of amblyopia has been a hot issue in the Department of Ophthalmology .At present, the main methods of amblyopia including refractive correction , cover therapy , medicine therapy , depression therapy , surgical treatment ( for form deprivation amblyopia ), comprehensive treatment, and so on.In recent years, the reconstruction of binocular visual function has been paid more and more attention in the treatment of amblyopia .On the basis of reviewing domestic and foreign literatures , the author reviewed the treatment methods and the latest

  11. TypeScript revealed

    CERN Document Server

    Maharry, Dan

    2013-01-01

    TypeScript Revealed is a quick 100-page guide to Anders Hejlsberg's new take on JavaScript. With this brief, fast-paced introduction to TypeScript, .NET, Web and Windows 8 application developers who are already familiar with JavaScript will easily get up to speed with TypeScript and decide whether or not to start incorporating it into their own development. TypeScript is 'JavaScript for Application-scale development'; a superset of JavaScript that brings to it an additional object-oriented-like syntax familiar to .NET programmers that compiles down into simple, clean JavaScript that any browse

  12. 基于MATLAB与OpenCV相结合的双目立体视觉测距系统%Binocular stereo vision distance measurement system based on a combination of Matlab and OpenCV

    Institute of Scientific and Technical Information of China (English)

    汪珍珍; 赵连玉; 刘振忠

    2013-01-01

    Binocular stereo vision distance measuring technology is a hot research topic in the field of machine vision. This paper focuses on a binocular stereo vision distance measurement system based on a combination of MATLAB and OpenCV, U-sing MATLAB camera calibration, and then import the results to OpenCV for subsequent image processing and stereo matching. Camera calibration via MATLAB Calibration Toolbox has better robustness and higher precision than in the artificial calibration and OpenCV calibration. The stereo matching adopt the SAD match which is a relatively rapid and real-time regional match and able to be better applied to actual projects.%双目立体视觉测距技术是当前机器视觉领域中的一个主要研究内容.本文设计了基于MATLABatlab与OpenCV相结合的双目立体视觉测距系统,利用MATLAB进行摄像机标定后将结果导入到OpenCV进行后续的图像处理与立体匹配.摄像机标定通过MATLAB标定工具箱来完成,较于人工标定和OpenCV标定具有更好的鲁棒性和较高的精确性.立体匹配采用区域匹配中相对快速实时的SAD匹配,能够更好的被应用于工程实际.

  13. Revealing the programming process

    DEFF Research Database (Denmark)

    Bennedsen, Jens; Caspersen, Michael Edelgaard

    2005-01-01

    One of the most important goals of an introductory programming course is that the students learn a systematic approach to the development of computer programs. Revealing the programming process is an important part of this; however, textbooks do not address the issue -- probably because the textb......One of the most important goals of an introductory programming course is that the students learn a systematic approach to the development of computer programs. Revealing the programming process is an important part of this; however, textbooks do not address the issue -- probably because...... the textbook medium is static and therefore ill-suited to expose the process of programming. We have found that process recordings in the form of captured narrated programming sessions are a simple, cheap, and efficient way of providing the revelation.We identify seven different elements of the programming...... process for which process recordings are a valuable communication media in order to enhance the learning process. Student feedback indicates both high learning outcome and superior learning potential compared to traditional classroom teaching....

  14. Outcomes of binocular vision after surgical corrections in concomitant strabismic patients%共同性斜视患儿手术前后三级视功能的临床观察

    Institute of Scientific and Technical Information of China (English)

    曾仁攀; 梁小琼; 王国平; 王丹玲

    2014-01-01

    Objective To observe the changes of binocular vision in concomitant strabismic patients before and af -ter surgical correction , and to discuss the importance of binocular vision reconstruction for concomitant strabismic patients . Methods Thirty-seven patients with constant comitant strabismus were enrolled .Patients received routine refraction and ophthalmic examinations .Distance and near esotropia were measured by prism-covering method .The simultaneous percep-tion and fusion were examined with a synoptophore , and the stereacuity was measured with stereograms .The patients who have ametropia must wear glasses when being examined .These data were recorded before surgery and 1 month, 3 months, and 6 months after surgery.Results Before surgery, eight patients exhibited simultaneous perception (21.6%), and sev-en patients showed binocular fusion (18.9%).The average fusion range was 1.90 ±4.15○.No patient had measurable stereopsis.Simultaneous perception significantly improved among the patients 1 month after surgery ( P <0.05).At 3 month and 6 month, simultaneous perception as well as binocular fusion and stereopsis all significantly improved ( P <0.05).Conclusion The loss of binocular vision in patients with comitant strabismus is severe .After surgical correction, binocular vision could improve significantly .Patients with constant comitant strabismus in China usually have longer disease course and are treated at older ages .Early screening , diagnosis and surgical correction for strabismus should be advocated .%目的:观察共同性斜视患者手术前后双眼视觉功能的变化,探讨手术矫正在共同性斜视患者双眼视觉功能重建中的重要性。方法收集了37例共同性斜视患者,手术前后分别进行眼部常规检查,屈光检查和三棱镜加交替遮盖法测定远、近斜视度;同时视、融合功能采用同视机检测,立体视功能采用颜少明编绘的《立体视觉检查图》检测。有屈光

  15. Android Emotions Revealed

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2012-01-01

    This work presents a method for designing facial interfaces for sociable android robots with respect to the fundamental rules of human affect expression. Extending the work of Paul Ekman towards a robotic direction, we follow the judgment-based approach for evaluating facial expressions to test...... in which case an android robot like the Geminoid|DK –a duplicate of an Original person- reveals emotions convincingly; when following an empirical perspective, or when following a theoretical one. The methodology includes the processes of acquiring the empirical data, and gathering feedback on them. Our...... findings are based on the results derived from a number of judgments, and suggest that before programming the facial expressions of a Geminoid, the Original should pass through the proposed procedure. According to our recommendations, the facial expressions of an android should be tested by judges, even...

  16. Clinal effects of LASIK on binocular vision in myopic anisometropia%近视性屈光参差患者LASIK术后双眼视功能评估

    Institute of Scientific and Technical Information of China (English)

    杨亮; 胡琦; 康杨; 黄磊; 王珂萌

    2012-01-01

    目的 观察近视性屈光参差患者接受准分子激光原位角膜磨镶术( LASIK)后双眼视功能的变化,探讨LASIK手术矫治近视性屈光参差对三级视功能的影响,从双眼视觉的变化评价其临床应用价值.设计前瞻性病例系列.研究对象36例(72眼)行LASIK手术的近视性屈光参差患者(双眼屈光参差≥2.50 D).方法 对36例行LASIK手术的近视性屈光参差患者分别于手术前和手术后3个月进行裸眼视力、最佳矫正视力、屈光状态和同视机双眼视功能的检测,并对双眼视功能的变化进行随访研究.主要指标手术前后裸眼视力、最佳矫正视力、屈光度、同时视、融合功能、远立体视和近立体视.结果 术前72眼的裸跟视力在0.01-0.2之间,术后3个月时均达到1.0.双跟屈光参差由术前的(5.01±1.96)D( 2.50~9.00 D),降低到术后3个月的( 0.28±0.22 )D(0.00~0.75 D).手术前后的屈光参差度的改变,差异均有显著统计学意义(P<0.01).26例屈光参差量≥2.50 D且≤6.00 D的高度屈光参差者术前戴框架眼镜下近立体视正常的12例,术后3个月增至22例,差异有统计学意义(P<0.05);16例屈光参差量>6.0D的重度屈光参差者手术前后均没有正常近立体视.术前戴框架眼镜下三级视功能(同时视、融合功能、远立体视)正常的分别为33例、18例、13例,LASIK术后3个月三级视功能正常的分别为34例、33例、23例,手术后获得融合功能和远立体视者较术前明显增加(P均<0.05).结论 LASIK矫治近视性屈光参差,不仅可提高患者裸眼视力,而且可通过减小患者双眼间的屈光差异,增加双眼物像的融合,改善立体视功能.%Objective To analyze the clinical effects on binocular vision after LASIK for myopic anisomelropia, and evaluate its clinical value in the view of vision quality. Design Prospective case series. Participants 36 cases (72 eyes) with myopic anisometropia who received

  17. Effect of cover adjustment on binocular vision function in children with anisometropic amblyopia%屈光参差性弱视患儿遮盖调节对双眼视功能的影响

    Institute of Scientific and Technical Information of China (English)

    朱凯

    2016-01-01

    Abstract• AIM: To explore and study the effect of cover adjustment on binocular visual function in children with anisometropic amblyopia.•METHODS: Forty -five children with anisometropic amblyopia of our hospital from July 2014 to April 2015 were as the study group, and treated by cover adjustment. Then 40 cases of healthy volunteers were selected as the blank control group.The binocular visual function of the subjects was observed.• RESULTS: Before treatments, at 1 and 3mo after treatments, the positive rates of binocular fusion were respectively 62%, 76% and 87%, which at 3mo after treatments was significantly higher than that before treatments ( P 0.05 ) .Before treatments, at 1 and 3mo after treatments the numbers of children whose stereo visions were 3000 "~801"were respectively 26,13 and 2, and the numbers of children whose stereo visions were 800 "~401"were respectively 12,13 and 6;the numbers of children whose stereo visions were 400 "~101"were respectively 7,15 and 25 ;the numbers of children whose stereo visions were≤100"were respectively 0,4 and 12. Far apart from the point of rupture and the convergence function in the study group after treatments were improved and significantly higher than those in the control group ( both P0.05 ) . After cover adjustment treatment, the lag of binocular regulation significantly decreased than that before treatments ( P 0.05 ) .In the study group ( 45 cases with 90 eyes) 52 eyes were cured, 24 eyes improved, 14 eyes ineffective;the total effective rate was 84%.• CONCLUSION: Cover adjustment has some improvement effect on binocular visual function in children with anisometropic amblyopia.%目的:探讨屈光参差性弱视患儿遮盖调节对双眼视功能的影响。方法:选取2014-07/2015-04在我院医治的屈光参差性弱视患儿45例作为研究组,应用遮盖治疗,同期选取40例志愿健康者作为空白对照组,观察受试者的双眼视功能情况。结

  18. Puerto Rico Revealed Preference data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Revealed preference models provide insights into recreational angler behavior and the economic value of recreational fishing trips. Revealed preference data is...

  19. Revealing the Beast Within

    Science.gov (United States)

    2003-07-01

    Deeply Embedded Massive Stellar Clusters Discovered in Milky Way Powerhouse Summary Peering into a giant molecular cloud in the Milky Way galaxy - known as W49 - astronomers from the European Southern Observatory (ESO) have discovered a whole new population of very massive newborn stars . This research is being presented today at the International Astronomical Union's 25th General Assembly held in Sydney, Australia, by ESO-scientist João Alves. With the help of infrared images obtained during a period of excellent observing conditions with the ESO 3.5-m New Technology Telescope (NTT) at the La Silla Observatory (Chile), the astronomers looked deep into this molecular cloud and discovered four massive stellar clusters, with hot and energetic stars as massive as 120 solar masses. The exceedingly strong radiation from the stars in the largest of these clusters is "powering" a 20 light-year diameter region of mostly ionized hydrogen gas (a "giant HII region"). W49 is one of the most energetic regions of star formation in the Milky Way. With the present discovery, the true sources of the enormous energy have now been revealed for the first time, finally bringing to an end some decades of astronomical speculations and hypotheses. PR Photo 21a/03 : Colour Composite of W49A (NTT+SOFI). PR Photo 21b/03 : Radio and Near-Infrared Composite of W49A Giant molecular clouds Stars form predominantly inside Giant Molecular Clouds which populate our Galaxy, the Milky Way. One of the most prominent of these is W49 , which has a mass of a million solar masses. It is located some 37,000 light-years away and is the most luminous star-forming region known in our home galaxy: its luminosity is several million times the luminosity of our Sun. A smaller region within this cloud is denoted W49A - this is one of the strongest radio-emitting areas known in the Galaxy . Massive stars are excessive in all ways. Compared to their smaller and ligther brethren, they form at an Olympic speed and

  20. 基于伪双目立体成像自动识别新技术%New Auto Identification Technology on Paper Currency Using Pseudo Binocular Stereo Imaging

    Institute of Scientific and Technical Information of China (English)

    曹晟; 聂旭云; 陈峥

    2012-01-01

    The current paper money identification techniques are based on safe-line, watermark, magnetic inks, fluorescence ink,etc. Alone with the development of fake technology,the anti-counterfeit technology needs new ways. This paper presented a brand-new anti-counterfeit method,which is based on the intaglio character of the paper currency,using a common flatbed scanner to achieve the pseudo binocular stereo image of the paper currency, and recognizing the relief texture to identify the real or fake currency. Furthermore, we also brought out a pseudo binocular stereo scanner prototype, which is a better currency detector with high efficiency. With the benefits of this scanner, our method can be applied automatically and is much faster.%现有的人民币伪钞等打印信息的识别技术主要是对钞票上的安全线、水印、磁性油墨、荧光油墨等物理特性进行识别.随着伪造技术的发展,特别是随着HD90、TJ55、AZ88、WL15、YX86等仿冒手段不断提高的伪钞的出现,对人民币的鉴伪技术提出了一种更高的要求.提出了一种基于人民币凹版印刷特性,利用普通平板扫描仪进行钞票的伪双目立体成像,对其浮雕纹理进行计算机自动识别,进而实现真、伪钞鉴别的新方法.通过实验验证了该方法的正确性和实用性.给出了基于此方法的伪双目立体成像扫描仪的快速验钞机原型设计.

  1. Pattern adaptation of relay cells in the lateral geniculate nucleus of binocular and monocular vision-deprived cats%双眼和单眼视觉剥夺猫外膝体细胞的图形适应

    Institute of Scientific and Technical Information of China (English)

    王伟; 寿天德

    2000-01-01

    为测定丘脑外膝体细胞的图形适应是否依赖于早期视觉经验, 在细胞外记录了双眼和单眼缝合的猫外膝体中继细胞对长时间运动光栅刺激的反应. 在双眼剥夺猫,占68%的记录到的细胞在30 s内反应下降到稳定值,其平均反应值下降33%,适应程度较正常猫显著.在单眼剥夺猫,记录到的剥夺眼驱动的和非剥夺眼驱动的细胞中,分别有占53%和44%的细胞显示图形适应, 两者差别不大.研究表明, 早期视剥夺能增强或保持图形适应, 提示图形适应是外膝体细胞常见的固有性质,可能主要由遗传因素所决定.%To test whether the pattern adaptation in thalamus is dependent upon postnatal visual experience during early life, the responses of relay cells to prolonged drifting grating stimulation were recorded extracellularly from the dorsal lateral geniculate nucleus (dLGN) of cats reared with binocular and monocular lid suture. In binocular vision-deprived cats, 68% of cells recorded showed significant adaptation to prolonged grating stimuli within 30 s, with a mean response decrease of 33%, and then stabilized gradually. This adaptation was stronger than that of relay cells in normal cats. In monocular vision-deprived cats, 53% of the cells driven by the deprived eye showed similar adaptation as did 44% of the cells driven by the non-deprived eye. These results indicate that pattern adaptation could be maintained or even enhanced after visual deprivation in early life. It is suggested that pattern adaptation is a general and intrinsic property of the dLGN cells, which may be mainly determined by genetic factors.

  2. Diffuse optical intracluster light as a measure of stellar tidal stripping: The cluster CL0024+17 at z ∼ 0.4 observed at the large binocular telescope

    Energy Technology Data Exchange (ETDEWEB)

    Giallongo, E.; Menci, N.; Grazian, A.; Gallozzi, S.; Castellano, M.; Fiore, F.; Fontana, A.; Pentericci, L.; Boutsia, K.; Paris, D.; Speziali, R.; Testa, V. [INAF—Osservatorio Astronomico di Roma, via di Frascati 33, I-00040 Monteporzio (Italy)

    2014-01-20

    We have evaluated the diffuse intracluster light (ICL) in the central core of the galaxy cluster CL0024+17 at z ∼ 0.4 observed with the prime focus camera (Large Binocular Camera) at the Large Binocular Telescope. The measure required an accurate removal of the galaxies' light within ∼200 kpc from the center. The residual background intensity has then been integrated in circular apertures to derive the average ICL intensity profile. The latter shows an approximate exponential decline as expected from theoretical cold dark matter models where the ICL is due to the integrated contribution of light from stars that are tidally stripped from the halo of their host galaxies due to encounters with other galaxies in the cluster cold dark matter (CDM) potential. The radial profile of the ICL over the galaxies intensity ratio (ICL fraction) is increasing with decreasing radius, but near the cluster center it starts to bend and then decreases where the overlap of the halos of the brightest cluster galaxies becomes dominant. Theoretical expectations in a simplified CDM scenario show that the ICL fraction profile can be estimated from the stripped over galaxy stellar mass ratio in the cluster. It is possible to show that the latter quantity is almost independent of the properties of the individual host galaxies but mainly depends on the average cluster properties. The predicted ICL fraction profile is thus very sensitive to the assumed CDM profile, total mass, and concentration parameter of the cluster. Adopting values very similar to those derived from the most recent lensing analysis in CL0024+17, we find a good agreement with the observed ICL fraction profile. The galaxy counts in the cluster core have then been compared with that derived from composite cluster samples in larger volumes, up to the clusters virial radius. The galaxy counts in the CL0024+17 core appear flatter and the amount of bending with respect to the average cluster galaxy counts imply a loss of

  3. Real-time 3D bare-hand gesture recognition using binocular vision videos%利用双目视觉视频的实时三维裸手手势识别

    Institute of Scientific and Technical Information of China (English)

    公衍超; 万帅; 杨楷芳; 陈浩; 李波

    2014-01-01

    为了解决三维裸手手势识别算法识别率低、易受类肤色物体干扰的问题,提出一种利用双目视觉视频的三维裸手手势识别算法。首先依据双目视觉原理推导出三维空间内手势深度与手势面积的关系,基于此关系对三维手势进行快速识别。为进一步降低算法复杂度,根据极线约束规则提出一种只计算手势质心匹配点的立体匹配算法。实验结果表明,与现有算法相比,所提算法性能在处理速度、识别准确率、鲁棒性方面均有明显提高。同时,提出的算法具有较强的开放性,可进一步根据需求定义、添加需识别的三维手势。%Current bare-hand based gesture recognition algorithms generally have the problems of low recognition accuracy and being prone to be affected by skin-like objects.In this paper,a 3D bare-hand gesture recognition algorithm is proposed using binocular vision videos.Firstly,a relationship between the depth and area of the gesture is achieved according to the principle of binocular vision,on the basis of which fast 3D gesture recognition is realized.To further speed up the method,a fast stereo matching algorithm is proposed following the epipolar line constraint rule,which regards the gesture’s centroid as the matching point.Experimental results have demonstrated that compared with existing algorithms the proposed algorithm significantly improves the performance in processing speed, recognition accuracy, and robustness.It should be noted that the proposed algorithm is open,where more 3D gestures can be easily added upon requirement.

  4. 双目立体视觉中水平调节机构的有限元分析%Finite element analysis on the level adjusting mechanism of binocular stereovision

    Institute of Scientific and Technical Information of China (English)

    卞德广; 朱兴龙; 周骥平; 杨晓俊; 朱军军

    2009-01-01

    On the basis of analyzing the importance of binocu-lar stereovision the model of imaging error analysis was established. Several kinds of level adjustment schemes were enumerated and compared, and the constitution and working process of the optimal scheme were narrated. Finally, by adopting the finite element ana-lytical software the precise calculation and analysis on the three pha-ses of the static work, the single motor work and the dual motor work of the level adjusting mechanism were earried out.%在分析了双目视觉重要性的基础上,建立了成像误差分析的模型,列举并比较了几种水平调节方案,叙述了最优方案的组成和工作过程.最后,采用有限元分析软件对水平调节机构的静态工作、单电机工作和双电机工作3个阶段进行了精确的计算和分析.

  5. 隐斜对成年人近视眼双眼调节反应与聚散适应的影响%Effect of heterophoria on binocular accommodation response and vergence adaptation of adult with myopia

    Institute of Scientific and Technical Information of China (English)

    肖婷婷; 高祥璐; 张艳龙; 王琦; 邢秀丽; 吕安琪

    2014-01-01

    Objective To study the effects of heterophoria type on binocular accommodation response and vergence adaptation of adult with myopia and to explore the related fact between heterophoria and the development of myopia.Methods Clinical case control study.There were 116 voluntary undergraduate or postgraduate with myopia from Tianjin Medical University investigated during September to November 2013.Participants were assigned to three groups according to near phorias (NP),including exophoria group (EXO) 42 participants (NP<-6△),esophoria group (ESO) 26 participants (NP>0△),normal phoria group (N) 48 participants (-6△≤NP≤0△).They were continuous to read vedio display terminal (VDT) at 40cm for 20 minutes.Operations including subjective refraction,distance (5m) and near (40cm) horizontal heterophoria,AC/A value,monocular (MA) and binocular (BA) accommodation response using Shin-Nippon WR-5100K open vision automatic infrared refractometer were performed before and after reading.Results The results demonstrated that the difference of MA and BA of the three groups had statistically significant difference.EXO group:BA>MA (t 9.264,P <0.001); N group:BA>MA (t =840,P <0.001); ESO group:MA>BA (t-6.064,P <0.001).The vergence adaptation of three groups had statistically significant difference (x2=4.026,P <0.001).EXO group showed convergence adaptation (less exophoria); ESO group and N group showed divergence adaptation (less esophoria in ESO group and more exophoria in N group).Conclusions The heterophoria type has effects on binocular accommodation response by vergence accommodation.The different types of heterophoria show vergence adaption with different direction in the effect of varying fusional vergence demands.There is a relationship between the esophoria with higher lag of binocular accommodation and the development of myopia.%目的 研究水平隐斜对聚散适应以及双眼调节反应的影响,探讨隐斜和近视发展速

  6. 角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响%Research on binocular vision after wearing orthoker-atology lens in adolescent myopic anisometropia

    Institute of Scientific and Technical Information of China (English)

    张春侠; 李自芳; 陈梅珠

    2015-01-01

    Objective To analyze the binocular vision after wearing orthokeratology lens in adolescent myopic anisometropia.Methods Twenty-three patients of retrospective cases with binocular myopic anisometropia more than 2.50 diopters received orthokeratology lens.All patients were followed 12-50 months,to observe the uncorrected visual acuity (UCVA),best-spectacles corrected visual acuity (BSCVA),refraction,binocular vision before and after wearing orthokeratology lens.Results The uncorrected visual acuity was improved significantly,the BCVA of 31 eyes (86.0%) reached or more than BSCVA.In the degree of anisometropia,there was a significant difference between before treatment (3.08±l.42)D and post-treatment (0.36±0.40)D.The myopia degree increased (0.22±0.38)D in high degree myopic eye after one year treatment,(0.16±0.30)D in low degree myopic eye.The short distance stereopsis vision after wearing orthokeratology lens was significantly higher than that before treatment (x2=27.22,P <0.01).And it was also significantly higher than that before treatment with corrected glasses (x2=15.51,P <0.01).Conclusions Orthokeratology lens can improve the UCVA,control the development of myopia and resume the binocular vision for adolescent myopic anisometropia.%目的 探讨角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响及临床价值.方法 回顾性临床分析研究.对2009年10月至2013年4月在南京军区福州总医院接受角膜塑形镜治疗,资料完整的23例(36只眼)屈光参差患者,持续戴镜12~50个月进行随访,观察治疗前及配戴角膜塑形镜裸眼视力(UCVA)、最佳矫正视力(BSCVA),屈光度数变化及双眼视觉.结果 配戴角膜塑形镜1年时裸眼视力(UCVA)达到或超过治疗前最佳矫正视力(BSCVA)的百分比为:86% (31/36).治疗前双眼屈光参差度数为(3.08±1.42)D,配戴角膜塑形镜为(0.36±0.40)D,较治疗前明显降低.配戴角膜塑形镜近视加深度数1

  7. 基于2D-3D双目运动估计的立体视觉定位算法%Stereo Visual Localization Algorithm Based on 2D-3D Binocular Motion Estimation

    Institute of Scientific and Technical Information of China (English)

    许允喜; 蒋云良; 陈方

    2011-01-01

    Motion estimation algorithm of stereo vision is one of the important factors which affect the accuracy of stereo visual localization. The traditional 3D-3D motion estimation is greatly affected by noise, so the accuracy of algorithm is not high. We propose a new stereo visual localization algorithm based on 2D-3D binocular motion estimation. In our method, 2D image projection coordinates is directly used instead of 3D coordinates of feature after motion. Firstly, EPnP motion estimation is applied to determine matching inliers and initial motion parameters. We propose 2 x 2D-3D motion parameters optimization method based on Levenberg-Marquardt algorithm and geometric constraints between the 2D projection of binocular cameras. Optimal 2D-3D motion estimation is achieved by minimizing the error between the observed 2×2D image points and the re-projected 2×2D image points of stereo cameras from the reconstructed 3D features. Simulated experiment and outdoor real experiment show that our method performs well in accuracy and robustness, and are better than traditional 3D-3D methods.%运动估计算法是影响立体视觉定位精度的重要因素,传统的3D-3D运动估计算法受噪声影响很大,计算精度不高.本文提出了一种基于2D-3D双目运动估计的立体视觉定位算法.算法不使用运动后的特征点3D坐标,而直接利用其2D图像投影坐标.首先,利用EPnP运动估计算法确定匹配内点和初始运动参数.接着,利用双目相机之间的2D投影几何约束,提出了基于Levenberg-Marquardt算法的2×2D-3D运动参数优化算法,利用确定的匹配内点和初始运动参数,使特征点在立体相机左右图像上的再投影误差最小,从而达到最优的立体相机2D-3D运动估计.仿真实验和户外真实实验表明:本文算法获得了很高的计算精度、鲁棒性,大大优于传统的基于3D-3D运动估计的立体视觉定位算法.

  8. Digital Calibration System of Binocular Photoelectric Equipment Optical Axis Parallelism%双目光电装备光轴平行性数字化检校系统设计

    Institute of Scientific and Technical Information of China (English)

    史云胜; 刘秉琦; 应家驹; 姜玉海

    2012-01-01

    设计了一种多光谱双目光电装备光轴平行性数字化检校系统。利用平行光管产生无限远白光、微光、红外目标,平行光经双目光电装备、光轴平移装置,将两路光线入射到面阵CCD上,目标图像经CCD、图像采集卡转换成数字图像信息送入计算机,利用软件算法得到光轴误差量,参考所建立的光电装备数学模型,给出光轴校正方案,利用辅助工具完成光轴平行性校正。该系统适用于多种双目光电装备,能够实现自动化检测,并给出数字化的光轴误差量,具有良好的通用性和可扩展性。%For the calibration system, a collimator is used to give white target, dim light target or IR target at infinity. Through the binocular photoelectric equipment and optical axis translation device, the two parallel lights will be incident to the area array CCD, and the target images are converted into digital image information by the CCD and frame grabber, which will be put into the computer, with which the optical axis deviation can be calculated. Then by referring to the mathematical model, the computer can give the optical axis correction program and assist in completing the parallel correction. The system is suitable for a variety of optoelectronic equipments; it can realize auto detection and display the optical axis deviation in digital form, obtaining good versatility and expansibility.

  9. Binocular Mobile Robot 3D Scene Reconstruction Based on Evidence Grid Model%基于栅格模型的双目移动机器人三维场景重建

    Institute of Scientific and Technical Information of China (English)

    李丹程; 刘景明; 姜琳颖; 刘雁集

    2012-01-01

    以投影几何学以及双目立体视觉原理为理论基础,对移动机器人的三维重建技术进行研究,对移动机器人漫道过程中所在的兴趣区域的场景进行较为精确的建模.设计了机器人的快速建模方法,利用迭代最近点算法( ICP),完成了多个局部三维场景模型的融合.同时,结合栅格投射理论,完成了对全局三维场景模型的更新.利用栅格模型重建的三维场景,具有环境信息丰富,模型描述精确的特点,可以应用于移动机器人导航领域.%Based on the theories of stereo vision and projective geometry, we study the technology of 3D reconstruction system, and build an accurate model for the interested area of a mobile robot during it roaming the road. By using the iterative closest point algorithm (ICP), we design a robot fast-modeling method which can integrate a number of local 3D scene models. At the same time, by com- bining grid projection theory, we accomplish the updating of global 3D scene model. Reconstructed by binocular stereo vision, the 3D scene with characteristics of abundant environment information and accurately described model can be applied for the navigation of mobile robot.

  10. 基于SIFT特征与区域相结合的双目视觉匹配算法%BINOCULAR VISION MATCHING ALGORITHM BASED ON COMBINATION OF SIFT FEATURES AND AREA

    Institute of Scientific and Technical Information of China (English)

    黄向东; 姬智华

    2014-01-01

    SIFT feature has features of keeping invariance against the variations in rotation,size scaling and brightness,considering these features,we use binocular vision system to collect stereo image pairs from two different vision angles,and propose a matching algorithm which is based on the combination of SIFT feature matching and improved area matching.The method determines the edge conforming to SIFT features as the reliable feature point and determines its parallax;the parallaxes of other points are determined according to parallax gradient principle,and finally the dense disparity map is then generated.Experimental results show that the introduction of matching algorithm combining the SIFT features and area improves the accuracy of the parallax of feature point,the matching of some weak texture areas is also improved.%以 SIFT 特征对旋转、尺度缩放、亮度变化保持不变性的特点,使用双目视觉系统从两个不同的视觉角度采集立体图像对,提出基于 SIFT 特征匹配和改进的区域匹配相结合的匹配算法。该方法确定符合 SIFT 特征的边缘为可靠特征点,并确定其视差;根据视差梯度原理确定其他点的视差,最后生成稠密的视差图。实验结果表明,SIFT 特征与区域相结合的匹配算法的引入,提高了特征点视差的准确性,一些弱纹理区的匹配也有所改善。

  11. 基于双目视觉的机器人目标定位与机械臂控制%Target Positioning and Mechanical Arm Control of Robot Based on Binocular Vision

    Institute of Scientific and Technical Information of China (English)

    晁衍凯; 徐昱琳; 周勇飞; 吕晓梦; 王明

    2013-01-01

    In order to interact with complex and changeable environments,finish the recognition and grab for object,a humanoid robot arm control method based on binocular vision is presented that employed in service robot.Manipulator is modeled by D-H method in this paper,the model is improved,a sample inverse arithmetic of humanoid manipulator is presented.The target object is recognized by color segmentation and the 3D position is computed by the stereo vision system.After positioning the target,a blind grasp is performed by the manipulator.Experimental results are conducted for illustration of effectiveness of the proposed methods,and the service robot can recognize and grab the object.%为了更好地与复杂多变的非结构化环境进行交互,完成对目标物体的识别和抓取,提出了一种应用于服务机器人平台的基于双目视觉的仿人机械臂控制方法.文中首先用D-H方法对机械臂进行建模,并对这个模型做了改进,给出了一种更加简便的3+1自由度仿人机械臂的逆解算法,采用基于双目视觉与颜色分割的目标识别方法;然后根据识别出的目标三维坐标信息控制机械臂完成抓取任务;最后,本方法在家庭服务机器人上得到了验证,机器人能够完成对目标物体的识别和抓取动作.

  12. Clinical observation of binocular vision function in concomitant strabismus patients before and after strabotomy%不同年龄共同性斜视手术前后三级视功能观察

    Institute of Scientific and Technical Information of China (English)

    曾仁攀; 曾庆华; 袁晓辉

    2013-01-01

    Objective To observe the changes of binocular vision function in comitant strabismus patients before and after surgery. Methods 37 patients with constant comitant strabismus were involved in the study. The simultaneous perception and fusion were examed by synotophore and the stereacuity was examed by Shaoming Yan's stereogram . The patients who have ametropia must wear rectified glasses when examing. Record above examination datas before surgery and one month , three months , six months after surgery . The patients were divided into two groups , 16 cases in the ≤9 years of age group and 21eases in the >9 years of age group. This study based on these datas. Results (1) Preoperative:The differences had statistical significance in the operation age and course ( P 0.05). (2) Postoperative :Comparation between the two groups, the differences had statistical significance in the simultaneous perception at one month, three months, six months after surgery ( P 0.05) ; At three months and six months after surgery the differences had statistical significance in the fusion and range of fusion ( P 0.05) ;The differences had statistical significance in the stereacuity at six months after surgery ( P 0. 05 ); The differences had statistical significance in the simultaneous perception, fusion and range of fusion, stereacuity at three months and six months after surgery ( P 9 years of age group after surgery compared with before surgery: The differences had no statistical significance in the function of vision at one month and three months after surgery ( P >0. 05) ;The differences had statistical significance in the range of fusion at six months after surgery (P 0.05). Conclusion ①According to the recovery and rebuilding of binocular vision function, the operation for patients with comitant strabismus should be taken before 9 years old. ②Active treatment also should be taken for the patients whose binocular vision function have matured . They also can get some extent

  13. Effect of binocular vision after part-time occlusion therapy in amblyopia children%间断遮盖治疗儿童弱视对视功能发育影响

    Institute of Scientific and Technical Information of China (English)

    王翠; 刘桂香; 马玉娜; 刘春莉

    2012-01-01

    目的 观察间断遮盖治疗对弱视患儿双眼视功能发育的影响.方法 对70例经治疗后双眼矫正视力均达0.9以上的弱视患儿行双眼视功能检查.测量同时视、融合范围及远近立体视.根据治疗过程中是否有遮盖史将患儿分为A(遮盖组)、B(不遮组)两组.统计A、B两组同时视、融合和立体视差异.结果 遮盖组中存在同时视的42人(91.3%),集合融合范围正常的2人(4.3%),分开融合范围正常的36人(78.3%),有正常远立体视的15人(32.6%),有正常近立体视的6人(13.0%).不遮组中存在同时视的23人(95.8%),集合融合范围正常的1人(4.2%),分开融合范围正常的17人(70.8%),有正常远立体视的10人(41.7%),有正常近立体视的3人(12.5%).70例患儿中存在正常远近立体视的各为25人(35.7%)、7人(10.0%).同时视在两组患儿之间的差异无统计学意义(x2=0.041,P=O.839);集合性融合和分开性融合在两组患儿之间的差异也无统计学意义(x2=0.156,P=0.693; x2=0.473,P=0.492);远近立体视两组患儿差异也均无统计学意义(x2=0.564,P=0.453;x2=0.004,P=0.949); 70例患儿正常远、近立体视获得率之间的差异具有统计学意义(x2=13.125,P=0.000).结论 弱视治疗后矫正视力正常的患儿短期内双眼视功能仍未完全恢复正常.间断遮盖优势眼治疗弱视不会对患儿双眼视功能发育造成显著的影响.%Objective To investigate the visual function after part-time occlusion therapy in amblyopia children whose corrected visual acuity recovered to normal. Methods Investigate the binocular vision of 70 cases amblyopia children whose corrected visual acuity had recovered to normal.According to whether patching dominant eye during treatment the children were divided into 2 groups (A and B).The statistically difference of simultaneous perception,fusion function and stereopsis in two groups was analyzed.Results Forty-two (91.3%) and 26 (95.8

  14. Decision Making and Revealed Preference

    DEFF Research Database (Denmark)

    de la Rosa, Leonidas Enrique

    If our decision-making processes are to some extent shaped by evolutionary pressures and our environment is different from that to which we adapted, some of our choices will not be in our best interest. But revealed preference is the only tool that we have so far to conduct a normative analysis...

  15. Revealed preference with limited consideration

    NARCIS (Netherlands)

    Demuynck, T.; Seel, C.

    2014-01-01

    We derive revealed preference tests for models where individuals use consideration sets to simplify their consumption problem. Our basic test provides necessary and sufficient conditions for consistency of observed choices with the existence of consideration set restrictions. The same conditions can

  16. Elusive Rivalry? Conceptions of the Philosophy of Education

    Science.gov (United States)

    White, John

    2010-01-01

    What is analytical philosophy of education (APE)? And what has been its place in the history of the subject over the past 50 years? In a recent essay in "Ethics and Education" (Vol. 2, No. 2, October 2007) on 'Rival conceptions of the philosophy of education', Paul Standish described a number of features of APE. Relying on both historical and…

  17. Rivalry of Advocacy Coalitions in the Czech Pension Reform

    Directory of Open Access Journals (Sweden)

    Potůček Martin

    2016-06-01

    Full Text Available The Czech Republic, as many other countries of Central and Eastern Europe, faced and is still facing a pension-reform challenge. The diversification of pension pillars led to the massive displacements of participant contributions from the public PAYG pension pillars to the newly constructed private, defined-contribution, fully-funded pillars. In the Czech Republic, the adoption of the relevant law was preceded by serious political conflict between supporters and opponents of this step (both among different political actors and among professionals. In an analysis of the conflict we critically apply the Advocacy Coalition Framework. We work mainly with the analysis of policy documents, public statements of the individual actors and an analysis of voting on the relevant law in both chambers of the Czech Parliament towards the identification of the crystallization process of two clear-cut coalitions between actors from both sides of the spectrum. The Advocacy Coalition Framework in exploring the dynamics of the public-policy process proved to be able to explain situations where there is sharp political conflict. Through the lens of the devil-shift of both camps (advocacy coalitions with different beliefs, each fell into extreme positions within the coalition to affirm the correctness of their arguments and positions.

  18. The Sino-Soviet Rivalry and Chinese Security Debate.

    Science.gov (United States)

    1982-10-01

    Victories," Hongqi, No. 15, 16 August 1981, in FBIS- China, 17 September 1981, pp. K10-K23. Sterba , James P., "China’s Army Follows New Marching Orders...provocative and original. Discussions with Rand colleagues Paul Langer, Norman Levin, James Thomson, and K. C. Yeh have also proved very helpful in shap- ing...Parks, 1980; Butterfield, 1980b; Butterfield, 1981; Sterba , 1981. 33 has also been unhappy about the severe downgrading of Mao Zedong’s historical

  19. Sibling rivalry among paralogs promotes evolution of the human brain.

    Science.gov (United States)

    Tyler-Smith, Chris; Xue, Yali

    2012-05-11

    Geneticists have long sought to identify the genetic changes that made us human, but pinpointing the functionally relevant changes has been challenging. Two papers in this issue suggest that partial duplication of SRGAP2, producing an incomplete protein that antagonizes the original, contributed to human brain evolution.

  20. Russian-Swedish Maritime Rivalry in XVIII cen.

    Directory of Open Access Journals (Sweden)

    Sergey A. Kolotov

    2014-03-01

    Full Text Available The paper analyzes the military-technical aspect of Russian-Swedish confrontation of the XVIII cen. Given short chronology of hostilities and influence the characteristics of the ships on the results of campaigns.

  1. [Henry Toussaint and Louis Pasteur. Rivalry over a vaccine].

    Science.gov (United States)

    Chevallier-Jussiau, Nadine

    2010-01-01

    Henry Toussaint (1847-1890) is a veterinary who studied in Veterinary School of Lyon with his great master Auguste Chauveau the famous physiologist. This place is the First School founded in Europe at the end of the XVIIIth century and has opened a way of thinking. His carrer brilliant and rich begins first in Lyon and then when he is named Professor of Anatomy and Physiology at the Veterinary School of Toulouse. Doctor of Science and Doctor of Medecine Toussaint applies "the experimental method" to his research in his laboratory and makes a lot of publications. He starts with Anatomy, then Physiology and soon he prioritizes his research to infestious diseases which cause serious damage to cattle in this time. He developes his own methods about anthrax an its "bacteridie", its nature, its way of culture and especially he studies the physiopathology of this disease. Pasteur is a renowned scientist who does study Microbiology at the same time in his laboratory in Paris, and precisely anthrax. He has explained his theories about "microbes" and has predominant advice. Toussaint admires Pasteur; in the year 1879 he finds first and isolates the microbe of "cholera des poules" (now Pasteurella) and gives Pasteur this new germ which will be used by Pasteur for his particular works about reducing of virulence by successive subcultures. In 1880 with his publishing on July 12 at the Academy of Science, Toussaint presents his successful result with an attenuated vaccine against anthrax: he has got protection against anthrax for dogs and sheep by using a vaccine which he has reduced off virulence by chemical manner. Academy congratulates him. Pasteur jealous of one's reputation contests the demonstration of Toussaint because he does not believe in the chemical method too different from his tests but will make use of this method for an experience open to the public in Pouilly-le-Fort in 1881. After this promotional event Pasteur will product and sell vaccines maked in his laboratory in Paris with the first chemical method of Toussaint. Pasteur gets glory and money. In the following time Toussaint tries another research on tuberculosis but soon he feels the first attacks of a neurologic illness and inescapably his mind declines until the death in 1890.

  2. Ecuadorean-Peruvian Rivalry in the Upper Amazon,

    Science.gov (United States)

    1978-01-01

    decide on joint action against the Axis, and Brazil’s Foreign Minister, Oswaldo Aranha , took the lead in working out a settlement of the Ecuadorean...the possibi- lity that Ecuador might be partitioned seemed real to Foreign Minister Tobar. In the end Tobar signed for the best deal Aranha could...Brazilian Foreign Minister, Dr. Oswaldo Aranha , was the author of most of the efforts at concilia- tion and, as it turned out, virtually the sole firial

  3. Beyond Rivalry and Camaraderie: Explaining Varying Asian Responses to China

    Science.gov (United States)

    2011-02-01

    EPAs with the Philippines, Malaysia, Mexico and Singapore. Japan signed two BITs: Vietnam (2003), and Korea (2002). 102 of bilateral economic ties...EPAs with Switzerland, ASEAN, Indonesia, Brunei, Thailand, Chile, Philippines, Malaysia, Mexico and Singapore. 369 Ibid, as of October 2008. The...Cooperative Partnership”," Comparative Connections, Vol. 2, No. 4, Jan 2001a. ---, "China-Korea Relations: Economic Interests Uber Alles: Hitting

  4. Based on Binocular Vision of Mobile Robot Obstacle Avoidance Algorithm Simulation%基于双目视觉的移动机器人避障算法仿真研究

    Institute of Scientific and Technical Information of China (English)

    何燚; 张翼飞

    2013-01-01

    针对当前超声波定位的机器人避障技术中,只能感知外围的单一信息,在多机器人通信或者外围存在信号串扰的前提下,信息转化测距结果存在较大误差,存在避障盲区的问题,提出一种视觉多图像信息融合的机器人避障算法,通过双目立体视觉采集机器人的实际图像信息,运用像素自适应融合方法最大程度的采集视觉信息,归一化后的视觉信息带入A*算法进行最优路径的选择,克服单一信息选择中路径计算的弊端,建立多信息约束的路径搜索模型,最大化的解决视觉避障中的干扰问题.后期的计算机仿真结果表明,与传统的测距避障算法相比,有效提高了算法的抗噪性能和避障准确性,为移动机器人避障优化提供了依据.%In view of the current based on ultrasonic positioning of the robot obstacle avoidance method, can only perception peripheral single information, in multi - robot communication or peripheral existing signal crosstalk, under the precondition of information transformation ranging results there is A big error, there exists obstacle avoidance blind area of the problems, the article proposes A kind of multiple image based on visual information fusion robot obstacle avoidance algorithm, through the binocular stereo vision acquisition robot actual image information, the use of pixel adaptive fusion method maximum acquisition visual information, normalization of visual information into the A * algorithm is optimal path choice, overcome A single information in the choice of the disadvantages of path is calculated and establish the multiple information constraint path search model, to solve the maximum visual obstacle a-voidance of interference problem. Later the computer simulation experiments to prove and traditional ranging obstacle avoidance algorithm, the algorithm improve the antinoise performance and obstacle avoidance accuracy, improvement effect is obvious..

  5. Digital Springback Measurement for Stamping Parts Based on Binocular Stereo Vision Measuring Technique%基于双目立体视觉测量技术的冲压件数字化回弹测量

    Institute of Scientific and Technical Information of China (English)

    路平; 刘斌; 黄常标; 林俊义; 徐正兴; 刘晓辉

    2013-01-01

    针对采用常规检具测量冲压件回弹量存在精度低、费用高、周期长等问题,提出数字化回弹测量方法.研制了基于光栅投影的双目立体视觉测量装置,应用该装置采集获取实际冲压件产品的三维点云数据;采用三步法将点云数据与产品的CAD设计模型匹配对齐,计算点云相对于设计模型在最佳匹配位置的法向偏差量,从而获得回弹量数值.生产实际中的应用表明:所研制的测量装置和数字化回弹测量系统通用性强,能实现对复杂、大型冲压件快速、灵活、精确的三维回弹测量.%To make up the deficiencies such as low accuracy, high cost and long cycle in measuring the springback of stamping parts by using traditional tools, a digital method for measuring the spring-back is proposed in the paper. A binocular stereo vision measuring equipment based on the grating projection method is devised and 3D point cloud data of actual stamping parts is acquired by applying this equipment. The point cloud data and CAD design model are matched and aligned through three steps method. The value of the springback is obtained by calculating the normal deviation distance of point cloud relative to the design model in the best matching position. Practical applications show that the measuring equipment and the digital springback measurement system developed have characteristic of strong generality, and they are able to measure the springback of complex and large stamping parts fast, flexibly and accurately.

  6. 基于眼球重建异面直线模型的双目视线跟踪算法%Binocular eye tracking algorithm based on eyeball rebuild skew lines model

    Institute of Scientific and Technical Information of China (English)

    郭政业; 胡雯蔷; 朱李瑾

    2016-01-01

    This paper combined 3D reconstruction method of light and shade with perspective model,and proposed advanced 3D construction method based upon perspective model,it reconstructed the eyeball model and solved the ambiguity problem. What’s more,it simplified the acquisition of depth information.It also proposed a skew lines model which did not need to cal-culate the depth information.With the help of model reconstruction and head motion compensation mechanism,high precision and real-time vision tracking result could be gained.This method reduced the complicacy of the equipment.In a word,binocular eye tracking algorithm based on eyeball rebuild skew lines model is an innovation for computer vision,and a new way for hu-man-computer technique.%结合了传统三维重建及眼部跟踪模型,结合透视投影模型的改进型三维重建法,解决了明暗法非唯一解问题,得到了眼球必要点的三维坐标;建立头动补偿的异面直线模型,它通过眼球重建所求三维坐标点,得到异面直线模型,无须计算深度信息,直接通过建模求解与补偿机制,快速得到视线落点位置,减少了设备复杂性,并提高了算法的精度。因此,基于眼球重建异面直线模型的双目视线跟踪算法是计算机视觉跟踪方法的一种创新,为人机交互应用提供了新的思路。

  7. Comparative analysis of binocular summation of pattern visual evoked potential before and after the surgery of concomitant strabismus%共同性斜视矫正术后双眼总和图形视觉诱发电位的对比分析

    Institute of Scientific and Technical Information of China (English)

    廖妙云; 中华; 黄海

    2014-01-01

    目的:通过分析共同性斜视矫正手术前后双眼总和图形视觉诱发电位的变化,探讨共同性斜视手术时机及其在斜视性弱视治疗中的作用。  方法:回顾性分析18岁以内在院接受共同性斜视矫正术治疗,且术后斜视矫正正位(斜视度≤±10△)的病历资料67例。按手术前斜视类型、接受手术时年龄、弱视程度分组,对各组术前、术后1,3 mo分别进行双眼总和P-VEP检测。结果以双眼反应/单眼反应( B/M)比值作为评价指标。  结果:所有病例术后1 mo B/M值均升高,差异有显著统计学意义(P12岁组明显(P  结论:经过弱视治疗后视力仍难以提高的共同性斜视患者建议6岁前行斜视矫正手术,特别是重度弱视及内斜视患儿(调节性内斜视除外)。早期手术有利于弱视的进一步治疗及双眼视功能的恢复。%AlM:To investigate the opportunity of the concomitant strabismus operation and the function in the treatment of strabismic amblyopia through analyzing the changes of binocular summation of pattern visual evoked potential ( P-VEP ) before and after the surgery of concomitant strabismus. METHODS: ln this retrospective study we investigated 67 cases admitted in our hospital. All patients were less than 18a and the postoperation squint angle was less than ± 10△. Patients were divided into three groups according to the strabismus type, age, and amblyopia degree. P-VEP binocular summation response was recorded in all cases, to observe the changes of the binocular summation response of P-VEP before strabismus surgery and 1mo, 3mo after surgery. The P-VEP response of binocular /monocular ( B/M ) ratio was taken as an evaluation index. RESULTS: B/M value of three groups all improved obviously 1mo after surgery, which the difference showed statistical significant (P12a group (P CONCLUSlON: Concomitant strabismus surgery is suggested to be performed before 6 years old when the patients are

  8. How Much of the Unconscious Is Just Pre - Threshold?

    Directory of Open Access Journals (Sweden)

    Manfred Wilhem Fahle

    2011-10-01

    Full Text Available Visual awareness is a specific form of consciousness. Binocular rivalry, the alternation of visual consciousness resulting when the two eyes view differing stimuli, allows one to experimentally investigate visual awareness. Observers usually indicate the gradual changes of conscious perception in binocular rivalry by a binary measure: pressing a button. However, in our experiments, gradual measures such as pupil and joystick movements start around 590 ms before observers press a button, apparently accessing even pre-conscious processes. Our gradual measures permit monitoring the built-up, over time, of decision processes and that should not be considered as abrupt events. Changes in analogue measures occurring before button presses signalling decisions do not prove these decisions are taken subconsciously – eliminating free will - but just prepared pre-thresholdly.

  9. Effect of correcting myopic anisometropia by Ortho K contact lens on binocular vision%角膜塑形镜矫正近视性屈光参差对双眼视功能的影响

    Institute of Scientific and Technical Information of China (English)

    兰小川; 石春和

    2016-01-01

    •AIM: To analyze the effects on binocular vision after wearing Ortho K ( OK ) contact lens for myopic anisometropia.•METHODS:A total of 40 cases of myopic anisometropia corrected by Ortho K contact lens were collected. The average age of participants was 11. 32 ± 2. 56y. The refractive error varied from -1. 25D to -5. 75D, on average-3. 18±1. 12D. The amount of myopic anisometropia was-4. 64±1. 52D. All the cases were followed-up for 3mo. The uncorrected visual acuity ( UCVA ) , best corrected visual acuity ( BCVA ) , refraction and binocular vision were checked pre-wearing Ortho K contact lens, and 3mo post wearing respectively.•RESULTS:The mean UCVA was 4. 0±0. 2, and BCVA was 4. 96±0. 2, the amount of myopic anisometropia was -4. 64 ±1. 52D pre-wearing OK contact lens. The mean UCVA was 4. 97 ± 0. 07, and BCVA was 4. 99 ± 0. 1, the amount of myopic anisometropia was 0. 23 ± 0. 12D, at post wearing OK lens 3 months respectively. The UCVA, BCVA, the amount of myopic anisometropia at post correction was significantly difference with pre-correction (P vision, 7 cases with peripheral stereo vision, and 6 cases with stereo vision blind. Macular fovea stereo vision was found in 27 cases, Abnormal stereo vision existed in 13 cases, including 7 cases with macula stereo vision, 3 cases with peripheral stereo vision, and 3 cases with stereo vision blind after wearing Ortho K contact lens 3mo.•CONCLUSION:Most myopic anisometropia patients can improve their visual acuity, reduce the refractive difference, and increase combined and stereopsis vision after wearing Ortho K contact lens 3mo.%目的:观察近视性屈光参差患者配戴角膜塑形镜后双眼视功能的变化。方法:选取40例配戴角膜塑形镜的近视性屈光参差患者,观察配戴前和配戴3 mo 后裸眼视力( uncorrected visual acuity,UCVA)、最佳矫正视力( best corrected visual acuity, BCVA)、屈光参差度、同视机双眼视功能、近立体视功能的变化

  10. Study of the affection to binocular visual function by the perceptual learning for children with intermittent exotropia%知觉学习对于间歇性外斜视儿童视功能影响的研究

    Institute of Scientific and Technical Information of China (English)

    俞佳伟; 梁斗立; 于雪冰; 顾若姝; 熊壮; 张玮玮

    2012-01-01

    目的 观察知觉学习训练对于儿童间歇性外斜视双眼视功能的影响.方法 42例间歇性外斜视患儿,行知觉学习训练.训练前及训练1个月、2个月、3个月后应用同视机检测Ⅰ级、Ⅱ级、Ⅲ级视功能,Titmus立体视觉检查图观察近立体视,同时进行间歇性外斜视斜视角检查.并对数据进行统计学分析.结果 42例患儿中,经同视机检查训练前Ⅰ级视功能20例,训练后1个月、2个月、3个月分别增加到24、27、32例,训练前与训练3个月后比较,差异有统计学意义(P<0.05);训练前Ⅱ级视功能20例,训练后1个月、2个月、3个月分别增加至23、26、30例,训练前与训练3个月后比较,差异有统计学意义(P<0.05);训练前Ⅲ级视功能18例,训练后1个月、2个月、3个月分别增加至23、25、30例,训练前与训练3个月后比较,差异有统计学意义(P<0.05);Titmus立体视觉检查图发现,训练前近立体视19例,训练后增加至21、23、29例,训练前与训练后3个月后比较,差异有统计学意义(P<0.05).训练前远方斜视角为28.33△±11.15△,训练1个月、2个月、3个月后分别为27.81△±10.87△,27.98△±11.28△,27.69△±11.56△,与训练3个月后比较,差异有统计学意义(P<0.05).结论 知觉学习训练治疗有助于间歇性外斜视患儿双眼视功能的重建,减少斜视度,对于未达到手术指证患者可以应用.%Objective To investigate the effect of binocular visual function of children with intermittent exotropia after perceptual learning. Methods A total of 42 children with intermittent exotropia were taken. Synoptophore was used to detect visual function at I stage, II stage and at HI stage. Titmus stereogram was used to detect near stereopsis. We also check the strabismus angle of these patinets. All data were recorded before learning and 1, 2 and 3 months after learning, then be statistically analyzed. Results In 42 children with intermittent

  11. Transparency masters for mathematics revealed

    CERN Document Server

    Berman, Elizabeth

    1980-01-01

    Transparency Masters for Mathematics Revealed focuses on master diagrams that can be used for transparencies for an overhead projector or duplicator masters for worksheets. The book offers information on a compilation of master diagrams prepared by John R. Stafford, Jr., audiovisual supervisor at the University of Missouri at Kansas City. Some of the transparencies are designed to be shown horizontally. The initial three masters are number lines and grids that can be used in a mathematics course, while the others are adaptations of text figures which are slightly altered in some instances. The

  12. Visibility of Monocular Symbology in Transparent Head-Mounted Display Applications

    Science.gov (United States)

    2015-07-08

    over terrain, were selected: 0.0 (low), 0.3 (medium), and 3.0 (high) eye-heights/second (0, 36, 324 kph). These ego -motion speeds correspond to no...i.e. thresholds worsen more than might be predicted by lack of summation alone). However, ego -motion does not appear to increase this suppression...E., Levi, D., Harwerth, R. & White, J. Color vision is altered during the suppression phase of binocular rivalry. Science (80-. ). 218, 802–804

  13. HELP: Handheld Emergency Logistics Program for Generating Structured Requests for Resources in Stressful Conditions

    Science.gov (United States)

    2014-09-01

    pilots using night vision goggles . 8 NATO Y: Technique of marking a landing zone using chemlights strung together in the shape of the letter “Y”. The...monocular Helmet Mounted Displays(HMDs) or night vision goggles may restrict peripheral vision and\\or introduce binocular rivalry (in the case of...Vietnam conflict, from the importance of treating for shock to leveraging helicopters to evacuate the wounded. However, these lessons paid off and

  14. Infant Face Preferences after Binocular Visual Deprivation

    Science.gov (United States)

    Mondloch, Catherine J.; Lewis, Terri L.; Levin, Alex V.; Maurer, Daphne

    2013-01-01

    Early visual deprivation impairs some, but not all, aspects of face perception. We investigated the possible developmental roots of later abnormalities by using a face detection task to test infants treated for bilateral congenital cataract within 1 hour of their first focused visual input. The seven patients were between 5 and 12 weeks old…

  15. Criteria for decompensation in binocular vision.

    Science.gov (United States)

    Jenkins, T C; Pickwell, L D; Yekta, A A

    1989-04-01

    Two groups of patients, one under 40 years of age and the other 40 years and over, were divided into subgroups according to whether they had symptoms associated with near vision. A method developed in 'signal detection theory' was used to determine whether a value could be found for heterophoria, or associated heterophoria, which would predict which patients had symptoms due to decompensated heterophoria in normal routine investigation. Receiver operator characteristic curves (ROC curves) were constructed to look for these cut-off values between patients with, and without, symptoms. No value for dissociated heterophoria was found that would discriminate between the symptomatic and asymptomatic patients. It is concluded that heterophoria measurement is not useful as a routine procedure. In the case of associated heterophoria, for the under 40 years age group, patients with a value of 1 prism dioptre or more are more likely to have symptoms than not, and one-third of patients with close work problems have a value of 2 prism dioptres or more. It was rare to find any asymptomatic patient with a value as high as this. In the 40 years and over age group those with an associated heterophoria of 2 prism dioptres or more are more likely to have symptoms than not. One-third of patients in the latter age group, with symptoms, have a value of 3 prism dioptres or more whilst it is rare to find an asymptomatic patient with a value as large as this.

  16. Asynchronous event-based binocular stereo matching.

    Science.gov (United States)

    Rogister, Paul; Benosman, Ryad; Ieng, Sio-Hoi; Lichtsteiner, Patrick; Delbruck, Tobi

    2012-02-01

    We present a novel event-based stereo matching algorithm that exploits the asynchronous visual events from a pair of silicon retinas. Unlike conventional frame-based cameras, recent artificial retinas transmit their outputs as a continuous stream of asynchronous temporal events, in a manner similar to the output cells of the biological retina. Our algorithm uses the timing information carried by this representation in addressing the stereo-matching problem on moving objects. Using the high temporal resolution of the acquired data stream for the dynamic vision sensor, we show that matching on the timing of the visual events provides a new solution to the real-time computation of 3-D objects when combined with geometric constraints using the distance to the epipolar lines. The proposed algorithm is able to filter out incorrect matches and to accurately reconstruct the depth of moving objects despite the low spatial resolution of the sensor. This brief sets up the principles for further event-based vision processing and demonstrates the importance of dynamic information and spike timing in processing asynchronous streams of visual events.

  17. Plan competitions reveal entrepreneurial talent

    Energy Technology Data Exchange (ETDEWEB)

    Madison, Alison L.

    2011-05-15

    Monthly economic diversity column for Tri-City Herald business section. Excerpt below: There’s something to be said for gaining valuable real-world experience in a structured, nurturing environment. Take for instance learning to scuba dive in the comfort of my resort pool rather than immediately hanging out with sharks while I figure out little things like oxygen tanks and avoiding underwater panic attacks. Likewise, graduate students are getting some excellent, supportive real-world training through university business plan competitions. These competitions are places where smart minds, new technologies, months of preparation and coaching, and some healthy pre-presentation jitters collide to reveal not only solid new business ideas, but also some promising entrepreneurial talent. In fact, professionals from around our region descend upon college campuses every spring to judge these events, which help to bridge the gap between academics and the real technology and business-driven economy.

  18. Binocular vision changes after phakic posterior chamber implantable collamer lens implantation%有晶状体眼后房型人工晶状体植入术后双眼视觉的变化

    Institute of Scientific and Technical Information of China (English)

    王晓贞; 付晶; 王京辉; 赵世强

    2015-01-01

    目的 评价有晶状体眼后房型人工晶状体(PPC-ICL)植入治疗高度近视术后患者双眼视觉的变化.方法 自身对照研究.行PPC-ICL植入术治疗高度近视患者42例,分别于术前和术后6个月行同视机的同时视、双眼融合、远立体视检查,采用颜少明《立体视觉检查图》检测近立体视锐度.采用Fisher's精确概率法对术前和术后6个月以上各参数进行统计分析.结果 术后6个月同时视功能与术前相比差异无统计学意义.远融合范围与远立体视锐度较术前有明显改善,差异有统计学意义(x2=0.357,P<0.01;x2=0.276,P<0.05).术后6个月与术前相比中心凹立体视功能和周边立体视功能较前改善,但差异无统计学意义.立体视盲者术后6个月较术前明显减少,差异有统计学意义(x2=0.279,P<0.05).结论 PPC-ICL植入术后患者同时视、双眼融合、远立体视功能及近立体视功能较术前明显改善.%Objective To evaluate the changes in binocular vision after phakic posterior chamber implantable collamer lens (PPC-ICL) implantation for high myopia.Methods This self-control study included 84 eyes of 42 patients with high myopia who underwent PPC-ICL implantation surgery.Simultaneous perception,fusion range,and distance and near stereopsis were tested before and 6 months after surgery with a synoptophore and stereogram designed by Yan Shaoming.Results There was no significant difference in simultaneous perception before surgery compared to 6 months after surgery,while the differences in fusion range and distance stereopsis were statistically significant (x2=0.357,P<0.01 and x2=0.276,P<0.05).There were no significant differences in foveal stereopsis and peripheral stereopsis before surgery compared to 6 months after surgery,but there was a significant difference in stereo blindness (x2=0.279,P<0.05).Conclusion Simultaneous perception,fusion range,and distance and near stereopsis after PPC-ICL implantation

  19. Design and implementation for control system of 53 cm binocular laser ranging telescope%53 cm双筒激光测距望远镜控制系统的设计与实现

    Institute of Scientific and Technical Information of China (English)

    黄涛; 李祝莲; 张海涛; 李语强; 熊耀恒

    2014-01-01

    The rapid and steady control system of the 53 cm binocular laser ranging telescope is constructed to realize the tracking and measurement of fast space targets. The modularized control system of the telescope was designed,in which the closed-loops of current and velocity are achieved by the servo driver,and the composite PID algorithm and feedback of position are realized by the motion controller. The control case is integrated and the controller is embedded. The controller is arranged to take charge of the real-time motion control,while the task management and human-computer interaction are realized by the host computer. Additionally,the user-defined communication protocol is formulated to overcome the communication delay and low timing precision of VC++. The control strategies of the 2th position closed-loop and the mixture PID are proposed to improve the tracking precision of the telescope. Experimental results indicate that the telescope can satisfy the precision of 5″ at the uniform speed of 3(°)/s and in the tracking process of low orbit satellites. Meanwhile,it reaches the precision of arc-second scale in the tracking of medium and high orbit satellites. The telescope has been proved that it is able to realize the rapid and steady tracking of space targets which are beyond 400 km far from the ground station,and can satisfy the demand of the property index.%研制53 cm双筒激光测距望远镜的快速平稳伺服控制系统,以实现快速空间目标的跟踪测量。模块化设计并构建望远镜的控制系统,伺服驱动器完成电流和速度的闭环,运动控制器实现位置环和复合PID算法。对控制机箱进行集成,并对控制器进行嵌入式开发,由控制器负责实时的运动控制,而上位机软件进行任务管理和人机交互。自定义通信协议以克服通信延时和VC++定时精度不高的问题,并提出位置二次闭环与混合PID的控制策略以提高望远镜的跟踪精度。实验

  20. Características estruturais maculares de olhos de pré-escolares nascidos prematuros: análise por tomografia de coerência óptica e oftalmoscopia binocular indireta

    Directory of Open Access Journals (Sweden)

    Lígia Beatriz Bonotto

    2013-04-01

    Full Text Available OBJETIVO: Comparar a estrutura retiniana da mácula e fóvea entre prematuros com retinopatia da prematuridade (ROP estágios II e III pós-tratamento, com ROP estágios II e III regredida espontaneamente e sem ROP, através de exames de tomografia de coerência óptica (OCT e da oftalmoscopia binocular indireta (OBI. MÉTODOS: Estudo do tipo transversal, observacional e não cego. Foram incluídas crianças prematuras nascidas entre 06/1992 e 06/2006 e examinadas entre 06/2009 e 12/2010; idade gestacional menor ou igual a 32 semanas e peso ao nascer menor ou igual a 1.599 g; com mínimo de três consultas durante o período de seleção; sem retinopatia da prematuridade ou com diagnóstico de ROP estágios II ou III em pelo menos um dos olhos com regressão espontânea ou após tratamento; máximo de seis meses de idade cronológica para o primeiro exame no serviço; idade cronológica mínima de quatro anos no período da reavaliação. Foram excluídas crianças prematuras que não compareceram ou que não tinham condições clínicas para a realização dos exames de reavaliação. Os prematuros foram divididos em três grupos: G1- com ROP pós-tratamento; G2- com ROP pós-regressão espontânea; e G3- sem ROP. Os exames realizados foram OBI e OCT. RESULTADOS: Vinte e quatro prematuros (48 olhos apresentaram os critérios exigidos para a pesquisa, com idade média cronológica entre 5 e 6 anos. À OBI, houve diferença estatística significativa para a presença de alterações na retina dos prematuros do grupo G1. No entanto estas alterações corresponderam às lesões cicatriciais deixadas pelo tratamento da ROP, sem comprometimento visível da região macular. À OCT houve diferença estatística significativa para a maior espessura foveal para os prematuros do grupo G1. Considerando-se o olho esquerdo, não houve diferença estatística significativa relacionada à espessura da fóvea entre G1 e G3. Não houve diferença entre os tr

  1. 3D Medical Electronic Endoscope System Based on Binocular Stereo Vision%基于双目立体视觉的医用三维电子内窥镜系统

    Institute of Scientific and Technical Information of China (English)

    冯大伟; 姜会林; 张光伟

    2012-01-01

    为了施行较为复杂的微创外科手术,设计了医用三维电子内窥镜系统,对系统的工作原理、显示方式等进行了分析.该系统基于双目立体视觉原理,采用双CCD摄像机模拟人眼实现了机器立体视觉;利用Zemax软件辅助设计了双光路内窥镜光学系统;通过比较几种立体显示方式的优缺点,选择了无源偏振眼镜立体显示方法,该方法采用基于FPGA的时分制立体显示技术,左右图像以100Hz帧频交替显示,并与液晶调制屏同步,观察者佩戴偏振眼镜即可观察到清晰无闪烁立体图像.经临床试验表明:简化了的光学系统的电子内窥镜图像质量得到显著提高;图像帧频达到100Hz,无闪烁感,且无停顿、拖尾、扭曲和停滞等现象.该系统可广泛应用于微创外科手术中,并可作为腹腔手术机器人的显示系统使用.%In order to perform more complex minimally invasive surgery, we designed 3D medical electronic endoscope system, and analyzed the system principle and display mode. The system based on the principle of binocular stereo vision achieves 3D machine vision, adopting the dual CCD cameras to simulate the human eye. A dual-optical endoscope system is designed by "Zemax" software. We choose the passive polarized glasses stereoscopic display through comparing the advantages and disadvantages of several 3D display ways, and this way adopts the time-division 3D display technology based on FPGA, the left and right images alternately display with 100Hz frame rate, and synchronize with the modulated LCD screen. When the viewers wear polarized glasses, they can observe the clear stereoscopic images without flicker. The clinical tests indicate that the images quality of electronic endoscope significantly improved by simplified optical system, the image frame rate reaches to 100Hz and is not flickering. The images have not stop, tailing, twist, and stagnation. The system can be widely used in minimally

  2. 儿童内斜视矫正术后双眼单视的建立及影响因素%Factors influencing binocular vision in children with successful surgical alignment for esotropia

    Institute of Scientific and Technical Information of China (English)

    杜宇; 孔香云; 王利华

    2012-01-01

    目的 观察和分析内斜视儿童眼位矫正术后双眼单视功能的建立情况及其影响因素.方法 回顾性系列病例研究.收集2008年11月至2011年9月间在山东大学附属省立医院眼科中心行共同性内斜视矫正手术并且术后随访眼位正位(≤±8△)的连续性病例111例.采用手电筒式Worth四点灯评估患儿的中心融合和周边融合;采用Titmus立体视图测定患儿的立体视锐度.采用x2检验比较不同内斜视类型之间周边融合建立的差异;采用Logistic回归分析内斜视类型、弱视治疗时间、手术年龄、两眼屈光参差差值、术后斜视度对周边融合建立的影响,并采用优势比(OR)进行比较.结果 111例内斜视儿童中,术后获得周边融合者68例(61.3%),其中获得中心融合者6例(5.4%);56例(50.5%)建立了不同程度的立体视.手术年龄(b=-0.842,P<0.01)、弱视治疗时间(b=-0.135,P<0.05)、最终随访的斜视度(b=-1.305,P<0.05)与术后周边融合的建立呈负相关;两眼屈光参差差值与术后周边融合的建立不相关(b=-19.670,P>0.05).4种内斜视类型之间术后周边融合建立的差异有统计学意义(x2=-15.977,P<0.01),周边融合建立的困难程度依次为先天性内斜视(OR=1.0)、非调节性内斜视(OR=3.008)、部分调节性内斜视(OR=4.475)、高AC/A型内斜视(0R=82.217).结论 内斜视儿童手术年龄愈早、术前弱视治疗时间愈短、术后斜视度愈小,术后愈易建立周边融合;4种内斜视类型中,建立周边融合的难易顺序依次为先天性内斜视、非调节性内斜视、部分调节性内斜视、高AC/A型内斜视.%Objective To investigate the binocular vision achieved in children after successful surgical alignment for esotropia and to identify clinical factors that may be associated with the outcome.Methods Consecutive cases surgically aligned within ±8 PD of orthotropia were consecutively reviewed during a follow

  3. Discussion of dimensional dayton training software on binocular vision rebuilding after concomitant exotropia surgery%维视顿训练软件对共同性外斜视术后双眼视功能重建的探讨

    Institute of Scientific and Technical Information of China (English)

    闫玉梅

    2016-01-01

    Objective To investigate the effect of dimensional dayton training software on binocular vision rebuilding after concomitant ex-otropia surgery. Methods 80 cases of patients with concomitant exotropia from March 2013 to March 2016 were randomly selected,these patients were divided into two groups according to pursuance treatment methods,the dayton-dimensional software training group(training group,n=40) and the control group( n=40 ). The control group did not receive binocular vision training,while the training group received binocular vision training by dimension dayton training software. Before and after treatment,the machine nearly three functions and Titmus stereopsis were examined and evaluated in the two groups,at the same time,eye position rollback results was compared in the two groups. Results The ratios of stageⅠ,Ⅱ,Ⅲ the training group were significantly higher( P ﹤0. 05). The foveal,macular holes,surrounding stereoscopic ratios were significantly higher( P ﹤0. 05). The proportion of no three-dimensional depending was significantly lower( P ﹤0. 05). The maintaining eye position an-teroposterior ratio was significantly higher( P ﹤0. 05),the strabismus rollback degree ratio was significantly lower than the control group( P ﹤0. 05). Conclusion The effect of dimensional dayton training software on binocular vision rebuilding after concomitant exotropia surgery is good.%目的探讨维视顿训练软件对共同性外斜视术后双眼视功能重建的效果。方法随机选取2013年3月至2016年3月收治的共同性外斜视患者80例,依据治疗方法将其分为两组,即维视顿训练软件组(训练组,n=40)和对照组( n=40)。对照组术后不进行双眼视功能训练,训练组术后采用维视顿训练软件进行双眼视功能训练。治疗前后分别检查和评定两组患者的同视机三级功能及Titmus近立体视锐度,同时,对两组患者的眼位回退结果进行统计。结果训

  4. Focus groups reveal consumer ambivalence.

    Science.gov (United States)

    1983-01-01

    According to qualitative research, Salvadoreans are ambivalent about the use of contraceptives. Since complete responsibility for management of the CSM project was accepted by the Association Demografica Salvadorena (ADS), the agency which operates the contraceptive social marketing project in El Salvador, in November 1980, the need for decisions in such areas as product price increases, introduction of new condom brands, promotion of the vaginal foaming tablet, and assessment of product sales performance had arisen. The ICSMP funded market research, completed during 1983, was intended to provide the data on which such decisions by ADS could be based. The qualitative research involved 8 focus groups, comprised of men and women, aged 18-45, contraceptive users and nonusers, from the middle and lower socioeconomic strata of the city of San Salvador and other suburban areas. In each group a moderator led discussion of family planning and probed respondents for specific attitudes, knowledge, and behavior regarding the use of contraceptives. To assess attitudes at a more emotional level, moderators asked respondents to "draw" their ideas on certain issues. A marked discrepancy was revealed between respondents' intellectual responses to the issues raised in group discussion, as opposed to their feelings expressed in the drawings. Intellectually, participants responded very positively to family planning practice, but when they were asked to draw their perceptions, ambivalent feelings emerged. Drawings of both the user and the nonuser convey primarily negative aspects for either choice. The user is tense and moody toward her children; the nonuser loses her attractiveness and "dies." Figures also show drawings of some of the attitudes of single and married male participants. 1 drawing shows an incomplete and a complete circle, symbolizing a sterilized man (incomplete) and a nonsterilized man (complete). Another picture depicts a chained man who has lost his freedom

  5. Revealing conceptual understanding of international business

    NARCIS (Netherlands)

    Ashley, S.; Schaap, H.; Bruijn, E. de

    2016-01-01

    This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students’ conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual

  6. Revealing conceptual understanding of international business

    NARCIS (Netherlands)

    Ashley, S.M.; Schaap, H.; de Bruijn, E.

    2016-01-01

    This study aims to identify an adequate approach for revealing conceptual understanding in higher professional education. Revealing students’ conceptual understanding is an important step towards developing effective curricula, assessment and aligned teaching strategies to enhance conceptual underst

  7. Las religiones y culturas de origen africano (Brasil, Cuba, Venezuela a prueba de políticas turísticas y rivalidades ¿ Un desarrollo sostenible ? Religions and cultures of African origin (Brazil, Cuba, Venezuela to test tourism policies and rivalries. A sustainable development? Religions et cultures d'origine africaine (Brésil, Cuba, Venezuela à l'épreuve des politiques touristiques et des rivalités. Un développement soutenable?

    Directory of Open Access Journals (Sweden)

    Montserrat Fitó

    2012-05-01

    Full Text Available Les religions1 d’origine africaine ont été transformées, au Brésil, à Cuba et plus récemment au Venezuela, en instruments pour augmenter la captation de devises, par le biais de programmes présentés par les autorités comme répondant aux normes du développement durable. Mais, tant le contrôle exercé sur ces manifestations culturelles, à des fins de commercialisation, que les rivalités engendrées entre pays, ou entre villes dans certains cas, mènent à une aliénation des acteurs de leur propre culture (après Guillermo Bonfill, contredisant la définition même de “développement durable”.The religions of African origin have been taken in Brazil, in Cuba and more recently in Venezuela as instruments to increase the inflow of currency, in tourism development programs presented by the authorities as sustainable. But the control exercised on them by the State organizations, with marketing purposes, as well as the rivalries between countries, as well as between cities of the same country in some cases, carry an alienation of the culture (according to Guillermo Bonfill's theory of cultural control, questioning the possibility of a balanced development, that is to say a sustainable development.Las religiones de origen africano han sido tomadas en Brasil, en Cuba y más recientemente en Venezuela como instrumento para incrementar la entrada de divisas, en programas de desarrollo del turismo presentados por las autoridades como sostenibles. Pero, tanto el control ejercido sobre ellas por los organismos oficiales, con fines de comercialización, como las rivalidades entre paises, así como en algún caso, entre ciudades de un mismo país, conllevan una enajenación de la cultura (según la teoría del control cultural de Guillermo Bonfill, cuestionando la posibilidad de un desarrollo equilibrado, es decir sostenible.

  8. Differences of accommodative responses between two eyes under binocular viewing condition mediated by polarizing glasses%偏光镜介导的双眼注视状态下调节反应差异性研究

    Institute of Scientific and Technical Information of China (English)

    王瑞卿; 张妍; 胡娱新; 何宇茜; 纪冬梅; 王淑荣

    2016-01-01

    variance analysis of repeated measuring and t test.RESULTS:Significant differences of accommodative responses between the two eyes were found under condition ( 1 ) and ( 2 ) at all the fixating distance. The accommodative responses in used eyes which can see the visual target were higher than in non-used eyes which cannot see the visual target ( P 0. 05).CONCLUSlON:Ciliary muscles in the used eyes were more relatively tonic than non - used eyes under binocular open viewing condition. The imbalance of accommodative responses between two eyes may be one of the risk factors resulting into the occurrence of myopia.

  9. Comparative study on binocular fusion and stereoacuity of patients with intermittent exotropia before and after surgery%间歇性外斜视手术矫正前后融合和立体视功能对照研究

    Institute of Scientific and Technical Information of China (English)

    赵淑静; 王利华

    2013-01-01

    Objective To compare the binocular fusion and stereoacuity achieved in patients before and after successful surgical alignment of intermittent exotropia.Methods Retrospective case series study.Consecutive cases of 114 patients of intermittent exotropia with successful surgical alignment (+5 ~-10PD) in the Eye Center of Provincial Hospital affiliated to Shandong University were retrospectively recruited.Titmus stereogram was used to evaluate the near stereoacuity and Worth 4dots flashlight test was used to evaluate the central and peripheral fusion of the patients before and after successful surgical alignment of intermittent exotropia.Prism and alternative cover test was used to evaluate the deviation of the patients fixating at accommodative targets of 6m and 33cm.Based on the angles examined after surgery,114 patients were divided into 4 groups (Group A:+1~+ 5PD; Group B∶ 0 PD; Group C∶-1~-5PD; Group D∶-6~-10PD).Chi-square test and nonparametric Wilcoxon signed rank test were used to compare the binocular fusion and stereoacuity of patients respectively before and after surgery,P <0.05 were considered statistically significant.Results There were significant difference statistically between binocular fusion evaluated before surgery and that after surgery in patients with intermittent exotropia (P =0.000).Binocular fusion evaluated after surgery was significantly different among 4 groups (P =0.004).There was statistical significance between stereoacuity examined before and after surgery (P =0.000).Stereoacuity examined before and after surgery was not significantly different in Group A (P =0.336),others had statistical significance (P =0.001).Conclusions There is significant improvement in binocular fusion and stereoacuity after successful surgical alignment of patients with intermittent exotropia,compared with that before surgery.%目的 对间歇性外斜视患者手术矫正前、后的双眼融合功能和立体视

  10. Binocular Vision Training on Postoperative Stereoscopic to Establish the Ef-ficacy of Concomitant Exotropia%双眼视觉训练对共同性外斜视术后立体视建立的疗效观察

    Institute of Scientific and Technical Information of China (English)

    闫玉梅

    2016-01-01

    目的:双眼视觉训练对共同性外斜视术后立体视建立的疗效探讨。方法方便选择该院2013年6月—2015年6月收治的接受共同性外斜视手术的患者60例为研究对象,将其随机分为两组,每组30例。对照组采用常规术后复健和护理,实验组在对照组的基础上进行双眼视觉训练。观察两组患者术后3个月和6个月立体视建立的情况。结果术后训练3个月,实验组立体视锐度为(154.1±20.3),对照组为(170.2±21.2),两组患者立体视锐度明显提高,且实验组提高幅度明显高于对照组;训练6个月末,观察组中的中心立体视人数较对照组要多,差异具有统计学意义。结论双眼的视觉训练有助于共同性外斜视患者术后立体视的建立,提高患者手术的成功率,值得研究推广。%Objective Postoperative stereoscopic binocular vision training of concomitant exotropia curative effect observa-tion.Methods Convenient selection from June 2013 —June 2015 in patients undergoing concomitant exotropia surgery 60 cases as the research object, its were randomly divided into two groups, each group 30 people.Control group using conven-tional postoperative rehabilitation and nursing, the experimental group in the control group on the basis of binocular vision training.Observe two groups of patients with postoperative 3 months and 6 months of a three-dimensional visual. Results Postoperative training for 3 months, two groups of patients with stereoscopic sharpness has improved significantly, and in-crease the experimental group is significantly higher than control group;6 month training, in the observation group center stereoscopic number more than the control group, the difference is statistically significant. Conclusion Binocular visual training helps the establishment of the stereoscopic postoperatively in patients with concomitant exotropia, improve the suc-cess rate of the patients with operation is worth

  11. Pilot study on a quality-of-life scale for school-age children with functional abnormalities in binocular vision%非斜视性双眼视异常学龄儿童生活质量量表研制

    Institute of Scientific and Technical Information of China (English)

    葛茸茸; 胡佳丽; 景明; 周哲; 孙琰; 高玉

    2016-01-01

    Objective To develop and evaluate a quality-of-life scale (QOL) for school-age children with functional abnormalities in binocular vision,and to evaluate its validity,reliability and responsiveness.Methods This was an investigation study.We designed a scale to evaluate the quality of life of school-age children with functional abnormalities in binocular vision,based on the design principle of the QOL,by statistical analysis,and by a comprehensive analysis of the opinions of experts in the binocular vision and public health fields.One hundred sixteen school-age children with functional abnormalities in binocular vision and 100 with normal vision were evaluated with the scale.Filter items and evaluation of validity,reliability and responsiveness were analyzed with a coefficient of variation,correlation coefficient,factor analysis,stepwise regression analysis,stepwise discriminatory analysis,Krone Bach's alpha coefficient,test-retest reliability and split half reliability.Results The 20-item scale covered four domains of QOL:binocular vision function,self-care ability,communication ability and psychology.The scale was rated for:Good format validity:Four common factors extracted by factor analysis were consistent with the four domains of the scale.Cumulative contribution rate:The cumulative contribution rate was 53.15%.Factor loading:Each item was above 0.50.Content validity:The correlation coefficient of the score for each item and its domain were more than 0.55.The correlation coefficient for the score of the four domains and the total score were 0.87,0.48,0.49,0.54,respectively.Discriminant validity:The score for children with functional abnormalities in binocular vision differed significantly from the normal group (t=1.97,P<0.01).The score after treatment was significantly different from before treatment (t=1.97,P<0.01).Test-retest reliability:Test retest reliability was 0.98 (P<0.01).Krone Bach's alpha coefficient:The coefficient was above 0.70.Split

  12. 利用功能磁共振成像定位人双眼垂直协同运动皮质中枢%Study on the location of cortical centre of binocular vertical movement in human by fMRI

    Institute of Scientific and Technical Information of China (English)

    钟士江; 李平; 包春雨

    2012-01-01

    [目的]确定人调控双眼垂直协同运动皮质中枢的位置.[方法]选择健康人12名作为受试者,功能磁共振成像(fMRI)使用GE Signa Highspeed MR/i 1.5T超导MRI仪及血氧水平依赖法(BOLD)fMRI技术对功能区进行成像.[结果]被激活脑区位于双侧额叶,集中于Brodmann 8区和6区的位置;功能信号强度及范围:右侧为主4例,左侧为主3例,单侧3例,双侧对称2例.[结论]人调控双眼垂直协同运动的皮质中枢位于Brodmann 8区和6区的位置;功能活动有偏侧、单侧及对称特点.fMRI是定位脑功能的有效工具.%[Objective] To locate the cortical centre of binocular vertical movement in humaan. [Methods] A total of 12 healthy subjects were selected in this experiment and scanned by GE Signa Highspeed MR/i 1.5 Tesla superconductive MRI system. Blood oxygenation level dependent(BOLD) method was used. [Results] Activation areas were found in the Brodmann area 8 and 6. The range and intensity of f unctional signals were: 4 cases mainly on the right side, 3 cases mainly on the left side and 3 cases only on one side, 2 cases symmetrically on both hemisphere. [Conclusions] The cortical centre of binocular vertical movement lies on the Brodmann area 8 and 6. Functional signals possess the asymmetric, symmetric and unilateral features.fMRI is an effective tool to locate the cortical centres.

  13. The Effect of Orthokeratology Lens for the Correction of Juvenile Myopia Anisometropia on Binocular Vision%角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响

    Institute of Scientific and Technical Information of China (English)

    纪冬梅

    2016-01-01

    目的:探讨角膜塑形镜矫正青少年近视性屈光参差对双眼视觉的影响。方法对在我院接受角膜塑形治疗的32例(50只眼)近视性屈光参差患者的临床资料进行回顾分析,比较患者治疗前后裸眼视力屈光参差度以及屈光度等的变化。结果治疗1年后裸眼视力达到或超过治疗前最佳矫正视力1.0以上45只眼,占90.0%。治疗前后患者屈光参差度分别为(3.12±1.21)D和(0.35±0.37)D,治疗前后差异有统计学意义(P<0.05)。治疗后近视加深速度与治疗前比较有所减缓。结论青少年近视性屈光参差患者接受角膜塑形治疗可有效改善患者双眼视觉功能。%Objective To investigate the influence of orthokeratology lens in correction of juvenile myopia anisometropia on binocular vision.Methods In our hospital accepted clinical data of orthokeratology treatment of 32 cases(50 eyes)with myopia refractive anisometropia patients who were retrospectively analyzed,compared before and after treatment in patients with naked eye visual acuity of anisometropia and refraction changes.ResultsAfter 1 years of treatment,the visual acuity reached or exceeded 45 of the best corrected visual acuity before treatment 1 years later,the proportion was 90.0%. Before and after treatment in patients with anisometropia were(3.12±1.21)D and(0.35±0.37)D,there were significant differences before and after the treatment(P<0.05). After the treatment,the rate of myopia deepening was somewhat slower than before treatment.Conclusion Juvenile myopia anisometropia patients undergoing orthokeratology therapy can effectively improve the patients with binocular visual function.

  14. Saturn's Rings Reveal Unexpected Phenomena

    Institute of Scientific and Technical Information of China (English)

    李颖

    2004-01-01

    Safely in orbit around Saturn, NASA's Cassini spacecraft sent back its first close-up images of the massive planet's rings on July 1, revealing an unexpectedly varied terrain featuring surprisingly sharp edges, braids and delicate ridges.

  15. REVEAL: Software Documentation and Platform Migration

    Science.gov (United States)

    Wilson, Michael A.; Veibell, Victoir T.

    2011-01-01

    The Research Environment for Vehicle Embedded Analysis on Linux (REVEAL) is reconfigurable data acquisition software designed for network-distributed test and measurement applications. In development since 2001, it has been successfully demonstrated in support of a number of actual missions within NASA's Suborbital Science Program. Improvements to software configuration control were needed to properly support both an ongoing transition to operational status and continued evolution of REVEAL capabilities. For this reason the project described in this report targets REVEAL software source documentation and deployment of the software on a small set of hardware platforms different from what is currently used in the baseline system implementation. This presentation specifically describes the actions taken over a ten week period by two undergraduate student interns and serves as an overview of the content of the final report for that internship.

  16. Revealing the Anatomy of Vote Trading

    CERN Document Server

    Guerrero, Omar A

    2016-01-01

    Cooperation in the form of vote trading, also known as logrolling, is central for law-making processes, shaping the development of democratic societies. Empirical evidence of logrolling is scarce and limited to highly specific situations because existing methods are not easily applicable to broader contexts. We have developed a general and scalable methodology for revealing a network of vote traders, allowing us to measure logrolling on a large scale. Analysis on more than 9 million votes spanning 40 years in the U.S. Congress reveals a higher logrolling prevalence in the Senate and an overall decreasing trend over recent congresses, coincidental with high levels of political polarization. Our method is applicable in multiple contexts, shedding light on many aspects of logrolling and opening new doors in the study of hidden cooperation.

  17. Mediastinal Mature Teratoma Revealed by Empyema

    Directory of Open Access Journals (Sweden)

    Mohammed Raoufi

    2016-01-01

    Full Text Available Teratomas are germ cell tumors, manifested with a great variety of clinical features; the most common extragonadal site is the anterior mediastinum. In this case, we report the patient with a large mature mediastinal teratoma with several components of ectodermal and endothermal epithelium. A 24-year-old female patient presented with history of persistent chest pain and progressively aggravating dyspnea for the previous 3 months. A chest X-ray showed a large opacity of the entire left hemithorax. Transcutaneous needle aspiration revealed a purulent fluid. The tube thoracostomy was introduced and the effusion was evacuated. Some weeks later, patient was seen in emergency for persistent cough and lateral chest pain. CT scan revealed a mass of the left hemithorax. The mass showed heterogeneous density, without compressing mediastinum great vessels and left hilar structures. Lipase value was elevated in needle aspiration. The patient underwent a total resection of the mediastinum mass via a left posterolateral thoracotomy. Microscopy revealed a mature teratoma with cystic structures. The patient subsequently made a full recovery. This case provide benign mediastinal teratoma with total atelectasis of left lung and elevated lipase value in needle transcutaneous aspiration; this event is explained by pancreatic component in the cystic tumor. Total removal of the tumor is adequate treatment for this type of teratoma and the prognosis is excellent.

  18. Fractal characterization of internally and externally generated conscious experiences.

    Science.gov (United States)

    Ibáñez-Molina, A J; Iglesias-Parro, S

    2014-06-01

    Although there is an extensive literature on the study of the neural correlates of consciousness (NCC) this is a subject that is far from being considered over. In this paper we present a novel experimental paradigm, based on binocular rivalry, to study internally and externally generated conscious experiences. We called this procedure bimodal rivalry. In addition, and assuming the non-linear nature of the EEG signals, we propose the use of fractal dimension to characterize the complexity of the EEG signal associated with each percept. Analysis of the data showed a significant difference in complexity between the internally generated and externally generated percepts. Moreover, EEG complexity was dissimilar for externally generated auditory and visual percepts. These results support fractal dimension analyses as a new tool to characterize conscious perception.

  19. Infections Revealing Complement Deficiency in Adults

    Science.gov (United States)

    Audemard-Verger, A.; Descloux, E.; Ponard, D.; Deroux, A.; Fantin, B.; Fieschi, C.; John, M.; Bouldouyre, A.; Karkowsi, L.; Moulis, G.; Auvinet, H.; Valla, F.; Lechiche, C.; Davido, B.; Martinot, M.; Biron, C.; Lucht, F.; Asseray, N.; Froissart, A.; Buzelé, R.; Perlat, A.; Boutboul, D.; Fremeaux-Bacchi, V.; Isnard, S.; Bienvenu, B.

    2016-01-01

    Abstract Complement system is a part of innate immunity, its main function is to protect human from bacterial infection. As genetic disorders, complement deficiencies are often diagnosed in pediatric population. However, complement deficiencies can also be revealed in adults but have been poorly investigated. Herein, we describe a case series of infections revealing complement deficiency in adults to study clinical spectrum and management of complement deficiencies. A nationwide retrospective study was conducted in French university and general hospitals in departments of internal medicine, infectious diseases enrolling patients older than 15 years old who had presented at least one infection leading to a complement deficiency diagnosis. Forty-one patients included between 2002 and 2015 in 19 different departments were enrolled in this study. The male-to-female ratio was 1.3 and the mean age at diagnosis was 28 ± 14 (15–67) years. The main clinical feature was Neisseria meningitidis meningitis 75% (n = 31/41) often involving rare serotype: Y (n = 9) and W 135 (n = 7). The main complement deficiency observed was the common final pathway deficiency 83% (n = 34/41). Half of the cohort displayed severe sepsis or septic shock at diagnosis (n = 22/41) but no patient died. No patient had family history of complement deficiency. The mean follow-up was 1.15 ± 1.95 (0.1–10) years. Half of the patients had already suffered from at least one infection before diagnosis of complement deficiency: meningitis (n = 13), pneumonia (n = 4), fulminans purpura (n = 1), or recurrent otitis (n = 1). Near one-third (n = 10/39) had received prophylactic antibiotics (cotrimoxazole or penicillin) after diagnosis of complement deficiency. The vaccination coverage rate, at the end of the follow-up, for N meningitidis, Streptococcus pneumonia, and Haemophilius influenzae were, respectively, 90% (n = 33/37), 47% (n = 17/36), and 35

  20. Apocalypto: revealing lost text with XMT

    Science.gov (United States)

    Mills, David; Davis, Graham R.; Lai, Yu-kun; Rosin, Paul

    2014-09-01

    "Can brute-force high-contrast tomography techniques and image processing techniques retrieve textual content from damaged heritage materials?" The Dental Institute at Queen Mary University of London (QMUL) is the leading centre for very high contrast X-Ray Microtomography imaging. The Apocalypto Project is our collaboration with the heritage community and experts in Computer Vision systems in the Computer Science Department at Cardiff University. This collaboration has developed techniques and a workflow that allows us to reveal textual content from moisture-damaged parchment rolls. This article will also present some initial results from burned and heat shrunken parchment rolls, an insect damaged Mamluk cap and a birch bark roll.

  1. Revealing Event Saliency in Unconstrained Video Collection.

    Science.gov (United States)

    Zhang, Dingwen; Han, Junwei; Jiang, Lu; Ye, Senmao; Chang, Xiaojun

    2017-04-01

    Recent progresses in multimedia event detection have enabled us to find videos about a predefined event from a large-scale video collection. Research towards more intrinsic unsupervised video understanding is an interesting but understudied field. Specifically, given a collection of videos sharing a common event of interest, the goal is to discover the salient fragments, i.e., the curt video fragments that can concisely portray the underlying event of interest, from each video. To explore this novel direction, this paper proposes an unsupervised event saliency revealing framework. It first extracts features from multiple modalities to represent each shot in the given video collection. Then, these shots are clustered to build the cluster-level event saliency revealing framework, which explores useful information cues (i.e., the intra-cluster prior, inter-cluster discriminability, and inter-cluster smoothness) by a concise optimization model. Compared with the existing methods, our approach could highlight the intrinsic stimulus of the unseen event within a video in an unsupervised fashion. Thus, it could potentially benefit to a wide range of multimedia tasks like video browsing, understanding, and search. To quantitatively verify the proposed method, we systematically compare the method to a number of baseline methods on the TRECVID benchmarks. Experimental results have demonstrated its effectiveness and efficiency.

  2. Transcriptome classification reveals molecular subtypes in psoriasis

    Directory of Open Access Journals (Sweden)

    Ainali Chrysanthi

    2012-09-01

    Full Text Available Abstract Background Psoriasis is an immune-mediated disease characterised by chronically elevated pro-inflammatory cytokine levels, leading to aberrant keratinocyte proliferation and differentiation. Although certain clinical phenotypes, such as plaque psoriasis, are well defined, it is currently unclear whether there are molecular subtypes that might impact on prognosis or treatment outcomes. Results We present a pipeline for patient stratification through a comprehensive analysis of gene expression in paired lesional and non-lesional psoriatic tissue samples, compared with controls, to establish differences in RNA expression patterns across all tissue types. Ensembles of decision tree predictors were employed to cluster psoriatic samples on the basis of gene expression patterns and reveal gene expression signatures that best discriminate molecular disease subtypes. This multi-stage procedure was applied to several published psoriasis studies and a comparison of gene expression patterns across datasets was performed. Conclusion Overall, classification of psoriasis gene expression patterns revealed distinct molecular sub-groups within the clinical phenotype of plaque psoriasis. Enrichment for TGFb and ErbB signaling pathways, noted in one of the two psoriasis subgroups, suggested that this group may be more amenable to therapies targeting these pathways. Our study highlights the potential biological relevance of using ensemble decision tree predictors to determine molecular disease subtypes, in what may initially appear to be a homogenous clinical group. The R code used in this paper is available upon request.

  3. Symptomatic hypopituitarism revealing primary suprasellar lymphoma

    Directory of Open Access Journals (Sweden)

    M'rabti Hind

    2010-11-01

    Full Text Available Abstract Background The most common cause of hypopituitarism is pituitary adenoma. However, in the case of suprasellar masses different etiologies are possible. We report an unusual case of primary suprasellar lymphoma presented with hypopituitarism. Case presentation A 26 year old woman presented with amenorrhea, galactorrhea and neurological disorders. Also, the laboratory work-up revealed partial hypopituitarism. The magnetic resonance imaging of the head showed a suprasellar mass. A presumptive diagnosis of granulomatous processes was made and the patient was given steroid therapy. Repeated brain MRI detected new lesions in the brain with regression of the suprasellar mass. Stereotactic biopsy of the paraventricular lesion revealed the diagnosis of B-cell lymphoma. Conclusion This case presentation reports a rare cause of hypopituitarism. Primary suprasellar lymphoma is extremely rare and represented a real diagnostic challenge. Besides, suprasellar masses are varied in aetiology and can present diagnostic problems for a radiologist. Also, because of the increased incidence of PCNSL, lymphoma must be kept in mind in the differential diagnosis of lesions in the suprasellar region.

  4. Stochastic homothetically revealed preference for tight stochastic demand functions

    OpenAIRE

    Jan Heufer

    2009-01-01

    This paper strengthens the framework of stochastic revealed preferences introduced by Bandyopadhyay et al. (1999, 2004) for stochastic homothetically revealed preferences for tight stochastic demand functions.

  5. Chemotaxis: new role for Ras revealed

    Institute of Scientific and Technical Information of China (English)

    Jianshe Yan; Dale Hereld; Tian Jin

    2010-01-01

    @@ A recent study of chemotaxis revealed a new role for the proto-oncogene Ras in the social ameba Dictyostelium discoideum.Chemotaxis,the directional movement of cells toward chemokines and other chemoattractants,plays critical roles in diverse physiological processes,such as mobilization of immune cells to fight invading microorganisms,targeting of metastatic cancer cells to specific tissues,and guidance of sperm cells to ova during fertilization.This work,published in the July 26 issue of The Journal of Cell Biology,was conducted in Dr.Devreotes' lab at John Hopkins University and Dr.Parent's lab at National Cancer Institute.This research team demonstrated that RasC functions as an upstream regulator of TORC2 and thereby governs the effects of TORC2-PKB signaling on the cytoskeleton and cell migration.

  6. Social patterns revealed through random matrix theory

    Science.gov (United States)

    Sarkar, Camellia; Jalan, Sarika

    2014-11-01

    Despite the tremendous advancements in the field of network theory, very few studies have taken weights in the interactions into consideration that emerge naturally in all real-world systems. Using random matrix analysis of a weighted social network, we demonstrate the profound impact of weights in interactions on emerging structural properties. The analysis reveals that randomness existing in particular time frame affects the decisions of individuals rendering them more freedom of choice in situations of financial security. While the structural organization of networks remains the same throughout all datasets, random matrix theory provides insight into the interaction pattern of individuals of the society in situations of crisis. It has also been contemplated that individual accountability in terms of weighted interactions remains as a key to success unless segregation of tasks comes into play.

  7. Double peaks reveal rare diplomonad sex.

    Science.gov (United States)

    Andersson, Jan O

    2012-02-01

    Diplomonads, single-celled eukaryotes, are unusual in having two nuclei. Each nucleus contains two copies of the genome and is transcriptionally active. It has long been assumed that diplomonads in general and Giardia intestinalis in particular are asexual. Genomic and population genetic data now challenge that assumption and extensive allelic sequence heterogeneity has been reported in some but not all examined diplomonad lineages. Here it is argued, in contrast to common assumptions, that allelic differences indicate recent sexual events, and isolates that have divided asexually for many generations have lost their allelic variation owing to within-cell recombination. Consequently, directed studies of the allelic sequence heterogeneity in diverse diplomonad lineages are likely to reveal details about the enigmatic diplomonad sexual life cycle.

  8. Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

    2013-01-01

    Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

  9. [Pneumothorax revealed by postoperative computed tomography].

    Science.gov (United States)

    Ikeda, Shizuka; Katori, Kiyoshi; Fujimoto, Minoru; Nitahara, Keiichi; Higa, Kazuo

    2005-11-01

    We report a case of pneumothorax revealed by postoperative computed tomography. A 39-year-old obese woman (height 153 cm, weight 70 kg) with fractures of the radius, ulna, clavicle, and femur in a traffic accident, was scheduled for osteosynthesis. Anesthesia was induced with thiopental and maintained with 50% nitrous oxide in oxygen and sevoflurane. The Spo2 decreased from 99% to 94% during the surgery. Bilateral chest sounds were symmetrical. The Spo2 increased to 100% after discontinuation of nitrous oxide. Pneumothorax was not evident on a postoperative chest X-ray, but computed tomography of the chest demonstrated right-sided pneumothorax. An ECG electrode had overlapped the fractured rib on the preoperative chest X-ray.

  10. Reward reveals dissociable aspects of sustained attention.

    Science.gov (United States)

    Esterman, Michael; Reagan, Andrew; Liu, Guanyu; Turner, Caroline; DeGutis, Joseph

    2014-12-01

    Although reward is known to have a powerful influence on performance, its effects on the ability to continuously sustain performance over time are poorly understood. The current study examines multiple measures of sustained attention (accuracy and variability) and their decrements over time, while introducing reward in the form of a monetary incentive or the promise of early completion. Compared with unrewarded participants, rewarded participants demonstrated greater overall accuracy and lower reaction time variability. However, rewarded and unrewarded participants displayed nearly identical decrements in performance over time, suggesting that these aspects of sustained attention are far less malleable by enhanced effort. This study helps to resolve conflicting models of sustained attention as it reveals that some aspects of performance are due to motivational lapses whereas others are due to the depletion of cognitive resources that cannot be easily overcome.

  11. Can Clustering in Genotype Space Reveal "Niches"?

    Science.gov (United States)

    D'Andrea, Rafael; Ostling, Annette

    2016-01-01

    Community ecology lacks the success enjoyed by population genetics to quantify the relative roles played by deterministic and stochastic processes. It has been proposed that clustered patterns of abundance in genotype space provide evidence of selection in microbial communities, since no such clustering would arise in the absence of selection. We critique this test for its unrealistic null hypothesis. We show mathematically and with simulations that point mutations alone lead to clustering in genotype space by causing correlations between abundances of similar genotypes. We also show potential deviations from the mutation-only pattern caused by immigration from a source pool. Clustered patterns in genotype space may still be revealing of selection if analyzed quantitatively but only if neutral and selective regimes can be distinguished once mutation and immigration are included in the null model.

  12. Revealing effective classifiers through network comparison

    CERN Document Server

    Gallos, Lazaros K

    2014-01-01

    The ability to compare complex systems can provide new insight into the fundamental nature of the processes captured in ways that are otherwise inaccessible to observation. Here, we introduce the $n$-tangle method to directly compare two networks for structural similarity, based on the distribution of edge density in network subgraphs. We demonstrate that this method can efficiently introduce comparative analysis into network science and opens the road for many new applications. For example, we show how the construction of a phylogenetic tree across animal taxa according to their social structure can reveal commonalities in the behavioral ecology of the populations, or how students create similar networks according to the University size. Our method can be expanded to study a multitude of additional properties, such as network classification, changes during time evolution, convergence of growth models, and detection of structural changes during damage.

  13. Revealed Quantum Information in Weak Interaction Processes

    CERN Document Server

    Hiesmayr, B C

    2014-01-01

    We analyze the achievable limits of the quantum information processing of the weak interaction revealed by hyperons with spin. We find that the weak decay process corresponds to an interferometric device with a fixed visibility and fixed phase difference for each hyperon. Nature chooses rather low visibilities expressing a preference to parity conserving or violating processes (except for the decay $\\Sigma^+\\longrightarrow p \\pi^0$). The decay process can be considered as an open quantum channel that carries the information of the hyperon spin to the angular distribution of the momentum of the daughter particles. We find a simple geometrical information theoretic interpretation of this process: two quantization axes are chosen spontaneously with probabilities $\\frac{1\\pm\\alpha}{2}$ where $\\alpha$ is proportional to the visibility times the real part of the phase shift. Differently stated the weak interaction process corresponds to spin measurements with an imperfect Stern-Gerlach apparatus. Equipped with this...

  14. Licking microstructure reveals rapid attenuation of neophobia.

    Science.gov (United States)

    Monk, Kevin J; Rubin, Benjamin D; Keene, Jennifer C; Katz, Donald B

    2014-03-01

    Many animals hesitate when initially consuming a novel food and increase their consumption of that food between the first and second sessions of access-a process termed attenuation of neophobia (AN). AN has received attention as a model of learning and memory; it has been suggested that plasticity resulting from an association of the novel tastant with "safe outcome" results in a change in the neural response to the tastant during the second session, such that consumption increases. Most studies have reported that AN emerges only an hour or more after the end of the first exposure to the tastant, consistent with what is known of learning-related plasticity. But these studies have typically measured consumption, rather than real-time behavior, and thus the possibility exists that a more rapidly developing AN remains to be discovered. Here, we tested this possibility, examining both consumption and individual lick times in a novel variant of a brief-access task (BAT). When quantified in terms of consumption, data from the BAT accorded well with the results of a classic one-bottle task-both revealed neophobia/AN specific to higher concentrations (for instance, 28mM) of saccharin. An analysis of licking microstructure, however, additionally revealed a real-time correlate of neophobia-an explicit tendency, similarly specific for 28-mM saccharin, to cut short the initial bout of licks in a single trial (compared with water). This relative hesitancy (i.e., the shortness of the first lick bout to 28-mM saccharin compared with water) that constitutes neophobia not only disappeared between sessions but also gradually declined in magnitude across session 1. These data demonstrate that the BAT accurately measures AN, and that aspects of AN-and the processes underlying familiarization-begin within minutes of the very first taste.

  15. Fractal characterization of neural correlates of consciousness

    Science.gov (United States)

    Ibañez-Molina, A. J.; Iglesias-Parro, S.

    2013-01-01

    In this work we present a novel experimental paradigm, based on binocular rivalry, to address the study of internally and externally generated conscious percepts. Assuming the nonlinear nature of the EEG signals, we propose the use of fractal dimension to characterize the complexity of the EEG associated with each percept. Data analysis showed significant differences in complexity between the internally and externally generated percepts. Moreover, EEG complexity of auditory and visual percepts was unequal. These results support fractal dimension analyses as a new tool to characterize conscious perception.

  16. Methods for Dichoptic Stimulus Presentation in Functional Magnetic Resonance Imaging - A Review

    Science.gov (United States)

    Choubey, Bhaskar; Jurcoane, Alina; Muckli, Lars; Sireteanu, Ruxandra

    2009-01-01

    Dichoptic stimuli (different stimuli displayed to each eye) are increasingly being used in functional brain imaging experiments using visual stimulation. These studies include investigation into binocular rivalry, interocular information transfer, three-dimensional depth perception as well as impairments of the visual system like amblyopia and stereodeficiency. In this paper, we review various approaches of displaying dichoptic stimulus used in functional magnetic resonance imaging experiments. These include traditional approaches of using filters (red-green, red-blue, polarizing) with optical assemblies as well as newer approaches of using bi-screen goggles. PMID:19526076

  17. The application of binocular indirect ophthalmomicroscope combined with anterior chamber maintainer in vitrectomy for complicated vitreoretinopathy%非接触双目间接眼底显微镜联合前房灌注在复杂玻璃体视网膜病变术中的应用

    Institute of Scientific and Technical Information of China (English)

    王永梅; 王莹; 楚艳华; 韩泉洪

    2012-01-01

    目的 观察使用非接触双目间接眼底显微镜(BIOM)联合前房灌注系统(ACM)行玻璃体切割术处理复杂玻璃体视网膜病变的临床疗效.方法 6例(6只眼)复杂玻璃体视网膜病变行玻璃体切割术时,为了避免医源性的脉络膜视网膜损伤,采用前房灌注来维持眼压,晶状体摘除及前部玻璃体切割后,切换至BIOM行玻璃体视网膜手术.临床随访3~11月,评估手术疗效及并发症.结果 6例BIOM联合ACM的玻璃体切割术在操作中未见明显困难.术后5例视力提高,1例无变化.主要长期并发症为低眼压、前部PVR、视网膜前膜.4例行硅油取出术后,视网膜在位. 结论 采用BIOM联合ACM行玻璃体切割术治疗复杂玻璃体视网膜病变安全、有效,在实践中具有可行性.%Objective To evaluate the clinical results of vitrectomy by using binocular indirect ophthalmomicroscope (BIOM) combined with anterior chamber maintainer (ACM) for complicated vitreoretinopathy.Methods Six cases (6 eyes) of complicated vitreoretinopathy were undergone vitrectomy,during which ACM was used to maintain intraocular pressure and prevent from iatrogenic injury of choroid and retina.After lens and anterior vitreous removal,vitrectomy was completed through a BIOM observation system.The follow-up time ranged from 3 months to 11 months.The effects and complications were analyzed.Results No obvious drawback was noticed during the 6 cases vitrectomy by using BIOM and ACM combination.The visual acuities improved in 5 cases and remained stable in 1 case after operation.The major long-term complications were hypotony,epiretinal membrane,and anterior proliferative vitreoretinopathy.Retinal reattached in 4 cases after silicone oil removal.Conclusions The vitrectomy combined BIOM with ACM is effective and safe for complicated vitreoretinopathy,and clinical results ascertained the practical feasibility of it.

  18. Revealing the values behind convenience food consumption.

    Science.gov (United States)

    Botonaki, Anna; Mattas, Konstadinos

    2010-12-01

    The increasing importance of convenience in consumer food choices has attracted researchers' interest. In the effort to understand how convenience affects consumers' food preferences, values are believed to play an important role. The present study attempts to examine the way personal values suggested by Schwartz (1992) are associated with behaviour and attitudes regarding convenience food. A number of constructs describing food related attitudes and behaviours were developed and their relationship with personal values was analyzed following the methodology proposed by Brunsø, Scholderer, and Grunert (2004). Data were collected through a questionnaire survey from a random sample of consumers in Thessaloniki city, Greece. The results reveal that convenience food consumption and convenience orientation in the food domain are mainly connected with values that motivate people to seek new experiences, act independently and enhance their own personal interests, while are in conflict with values of conservation and self-transcendence. The opposite holds for other food related attitudes and behaviours like involvement with cooking and variety in diet. The findings seem to be of particular interest not only for marketers of food products, but also for food policy makers.

  19. VISTA Reveals the Secret of the Unicorn

    Science.gov (United States)

    2010-10-01

    A new infrared image from ESO's VISTA survey telescope reveals an extraordinary landscape of glowing tendrils of gas, dark clouds and young stars within the constellation of Monoceros (the Unicorn). This star-forming region, known as Monoceros R2, is embedded within a huge dark cloud. The region is almost completely obscured by interstellar dust when viewed in visible light, but is spectacular in the infrared. An active stellar nursery lies hidden inside a massive dark cloud rich in molecules and dust in the constellation of Monoceros. Although it appears close in the sky to the more familiar Orion Nebula it is actually almost twice as far from Earth, at a distance of about 2700 light-years. In visible light a grouping of massive hot stars creates a beautiful collection of reflection nebulae where the bluish starlight is scattered from parts of the dark, foggy outer layers of the molecular cloud. However, most of the new-born massive stars remain hidden as the thick interstellar dust strongly absorbs their ultraviolet and visible light. In this gorgeous infrared image taken from ESO's Paranal Observatory in northern Chile, the Visible and Infrared Survey Telescope for Astronomy (VISTA [1], eso0949) penetrates the dark curtain of cosmic dust and reveals in astonishing detail the folds, loops and filaments sculpted from the dusty interstellar matter by intense particle winds and the radiation emitted by hot young stars. "When I first saw this image I just said 'Wow!' I was amazed to see all the dust streamers so clearly around the Monoceros R2 cluster, as well as the jets from highly embedded young stellar objects. There is such a great wealth of exciting detail revealed in these VISTA images," says Jim Emerson, of Queen Mary, University of London and leader of the VISTA consortium. With its huge field of view, large mirror and sensitive camera, VISTA is ideal for obtaining deep, high quality infrared images of large areas of the sky, such as the Monoceros R2 region

  20. Balance Trees Reveal Microbial Niche Differentiation.

    Science.gov (United States)

    Morton, James T; Sanders, Jon; Quinn, Robert A; McDonald, Daniel; Gonzalez, Antonio; Vázquez-Baeza, Yoshiki; Navas-Molina, Jose A; Song, Se Jin; Metcalf, Jessica L; Hyde, Embriette R; Lladser, Manuel; Dorrestein, Pieter C; Knight, Rob

    2017-01-01

    Advances in sequencing technologies have enabled novel insights into microbial niche differentiation, from analyzing environmental samples to understanding human diseases and informing dietary studies. However, identifying the microbial taxa that differentiate these samples can be challenging. These issues stem from the compositional nature of 16S rRNA gene data (or, more generally, taxon or functional gene data); the changes in the relative abundance of one taxon influence the apparent abundances of the others. Here we acknowledge that inferring properties of individual bacteria is a difficult problem and instead introduce the concept of balances to infer meaningful properties of subcommunities, rather than properties of individual species. We show that balances can yield insights about niche differentiation across multiple microbial environments, including soil environments and lung sputum. These techniques have the potential to reshape how we carry out future ecological analyses aimed at revealing differences in relative taxonomic abundances across different samples. IMPORTANCE By explicitly accounting for the compositional nature of 16S rRNA gene data through the concept of balances, balance trees yield novel biological insights into niche differentiation. The software to perform this analysis is available under an open-source license and can be obtained at https://github.com/biocore/gneiss. Author Video: An author video summary of this article is available.

  1. Myasthenia Revealed Following Laparotomy - A Case Report

    Directory of Open Access Journals (Sweden)

    Abdelilah GHANNAM

    2015-06-01

    Full Text Available Myasthenia (muscle weakness is a rare neuromuscular disease of which respiratory failure is the main complication. The accidental discovery of such disease in the perioperative period is rare and potentially serious.We report a case of a woman who underwent emergency operation for appendiceal peritonitis, and failed repeatedly at weaning from postoperative mechanical ventilation. The usual etiologies such as postoperative respiratory complications, ventilator-associated pneumonia, acute respiratory distress syndrome complicating the septic shock or having no impact on it, and neuromyopathy’s resuscitation were considered, researched, examined or eliminated.Faced with the diagnostic impasse and the obvious weaning failure, another interview revealed signs of muscle fatigue which led to the diagnosis of myasthenia gravis decompensated perioperatively. Once the diagnosis was confirmed by means of a neostigmine test, the specific treatment began, particularly through plasma exchange sessions, and the process of weaning resumed. The result was complete weaning. A three-month follow-up showed a stable patient with no significant muscular disability.

  2. ERYTHEMA NODOSUM REVEALING ACUTE MYELOID LEUKEMIA

    Directory of Open Access Journals (Sweden)

    Chebbi Wafa

    2013-07-01

    Full Text Available Introduction: Erythema nodosum (EN is the most common type of panniculitis. It may be idiopathic or secondary to various etiologies. However, the occurrence of erythema nodosum in malignant hemopathy had rarely been reported. Case report: A 42 year-old woman presented with a four week history of recurrent multiple painful erythematous nodules developed on the lower limbs associated with arthralgia of the ankles and fever. The clinical features of skin lesions with contusiform color evolution allowed establishing the diagnosis of EN. No underlying cause was found. The skin lesions were improved with non-steroidal anti-inflammatory drugs and colchicine. Three months later, the patient consulted for recurrence of EN associated with fever, inflammatory polyarthralgia and hepatosplenomegaly. The peripheral blood count revealed pancytopenia. A bone marrow examination confirmed the diagnosis of acute myeloid leukemia type 2. Initiation of chemotherapy was followed by the complete disappearance of skin lesions of EN. Conclusion: Paraneoplastic erythema nodosum is a rare entity. In the literature, a few cases of association with leukemia have been reported. Exploration for solid neoplasms or hemopathy in case of recurrent EN or resistance to conventional treatment should be systematic

  3. Balance Trees Reveal Microbial Niche Differentiation

    Science.gov (United States)

    Morton, James T.; Sanders, Jon; Quinn, Robert A.; McDonald, Daniel; Gonzalez, Antonio; Vázquez-Baeza, Yoshiki; Navas-Molina, Jose A.; Metcalf, Jessica L.; Hyde, Embriette R.; Lladser, Manuel; Dorrestein, Pieter C.

    2017-01-01

    ABSTRACT Advances in sequencing technologies have enabled novel insights into microbial niche differentiation, from analyzing environmental samples to understanding human diseases and informing dietary studies. However, identifying the microbial taxa that differentiate these samples can be challenging. These issues stem from the compositional nature of 16S rRNA gene data (or, more generally, taxon or functional gene data); the changes in the relative abundance of one taxon influence the apparent abundances of the others. Here we acknowledge that inferring properties of individual bacteria is a difficult problem and instead introduce the concept of balances to infer meaningful properties of subcommunities, rather than properties of individual species. We show that balances can yield insights about niche differentiation across multiple microbial environments, including soil environments and lung sputum. These techniques have the potential to reshape how we carry out future ecological analyses aimed at revealing differences in relative taxonomic abundances across different samples. IMPORTANCE By explicitly accounting for the compositional nature of 16S rRNA gene data through the concept of balances, balance trees yield novel biological insights into niche differentiation. The software to perform this analysis is available under an open-source license and can be obtained at https://github.com/biocore/gneiss. Author Video: An author video summary of this article is available. PMID:28144630

  4. Quadrupole transitions revealed by Borrmann spectroscopy.

    Science.gov (United States)

    Pettifer, Robert F; Collins, Stephen P; Laundy, David

    2008-07-10

    The Borrmann effect-a dramatic increase in transparency to X-ray beams-is observed when X-rays satisfying Bragg's law diffract through a perfect crystal. The minimization of absorption seen in the Borrmann effect has been explained by noting that the electric field of the X-ray beam approaches zero amplitude at the crystal planes, thus avoiding the atoms. Here we show experimentally that under conditions of absorption suppression, the weaker electric quadrupole absorption transitions are effectively enhanced to such a degree that they can dominate the absorption spectrum. This effect can be exploited as an atomic spectroscopy technique; we show that quadrupole transitions give rise to additional structure at the L(1), L(2) and L(3) absorption edges of gadolinium in gadolinium gallium garnet, which mark the onset of excitations from 2s, 2p(1/2) and 2p(3/2) atomic core levels, respectively. Although the Borrmann effect served to underpin the development of the theory of X-ray diffraction, this is potentially the most important experimental application of the phenomenon since its first observation seven decades ago. Identifying quadrupole features in X-ray absorption spectroscopy is central to the interpretation of 'pre-edge' spectra, which are often taken to be indicators of local symmetry, valence and atomic environment. Quadrupolar absorption isolates states of different symmetries to that of the dominant dipole spectrum, and typically reveals orbitals that dominate the electronic ground-state properties of lanthanides and 3d transition metals, including magnetism. Results from our Borrmann spectroscopy technique feed into contemporary discussions regarding resonant X-ray diffraction and the nature of pre-edge lines identified by inelastic X-ray scattering. Furthermore, because the Borrmann effect has been observed in photonic materials, it seems likely that the quadrupole enhancement reported here will play an important role in modern optics.

  5. Quantitative proteomics reveals cellular targets of celastrol.

    Directory of Open Access Journals (Sweden)

    Jakob Hansen

    Full Text Available Celastrol, a natural substance isolated from plant extracts used in traditional Chinese medicine, has been extensively investigated as a possible drug for treatment of cancer, autoimmune diseases, and protein misfolding disorders. Although studies focusing on celastrol's effects in specific cellular pathways have revealed a considerable number of targets in a diverse array of in vitro models there is an essential need for investigations that can provide a global view of its effects. To assess cellular effects of celastrol and to identify target proteins as biomarkers for monitoring treatment regimes, we performed large-scale quantitative proteomics in cultured human lymphoblastoid cells, a cell type that can be readily prepared from human blood samples. Celastrol substantially modified the proteome composition and 158 of the close to 1800 proteins with robust quantitation showed at least a 1.5 fold change in protein levels. Up-regulated proteins play key roles in cytoprotection with a prominent group involved in quality control and processing of proteins traversing the endoplasmic reticulum. Increased levels of proteins essential for the cellular protection against oxidative stress including heme oxygenase 1, several peroxiredoxins and thioredoxins as well as proteins involved in the control of iron homeostasis were also observed. Specific analysis of the mitochondrial proteome strongly indicated that the mitochondrial association of certain antioxidant defense and apoptosis-regulating proteins increased in cells exposed to celastrol. Analysis of selected mRNA transcripts showed that celastrol activated several different stress response pathways and dose response studies furthermore showed that continuous exposure to sub-micromolar concentrations of celastrol is associated with reduced cellular viability and proliferation. The extensive catalog of regulated proteins presented here identifies numerous cellular effects of celastrol and constitutes

  6. Revealing atropisomer axial chirality in drug discovery.

    Science.gov (United States)

    LaPlante, Steven R; Edwards, Paul J; Fader, Lee D; Jakalian, Araz; Hucke, Oliver

    2011-03-07

    An often overlooked source of chirality is atropisomerism, which results from slow rotation along a bond axis due to steric hindrance and/or electronic factors. If undetected or not managed properly, this time-dependent chirality has the potential to lead to serious consequences, because atropisomers can be present as distinct enantiomers or diastereoisomers with their attendant different properties. Herein we introduce a strategy to reveal and classify compounds that have atropisomeric chirality. Energy barriers to axial rotation were calculated using quantum mechanics, from which predicted high barriers could be experimentally validated. A calculated rotational energy barrier of 20 kcal mol(-1) was established as a suitable threshold to distinguish between atropisomers and non-atropisomers with a prediction accuracy of 86%. This methodology was applied to subsets of drug databases in the course of which atropisomeric drugs were identified. In addition, some drugs were exposed that were not yet known to have this chiral attribute. The most valuable utility of this tool will be to predict atropisomerism along the drug discovery pathway. When used in concert with our compound classification scheme, decisions can be made during early discovery stages such as "hit-to-lead" and "lead optimization," to foresee and validate the presence of atropisomers and to exercise options of removing, further stabilizing, or rendering the chiral axis of interest more freely rotatable via SAR design, thereby decreasing this potential liability within a compound series. The strategy can also improve drug development plans, such as determining whether a drug or series should be developed as a racemic mixture or as an isolated single compound. Moreover, the work described herein can be extended to other chemical fields that require the assessment of potential chiral axes.

  7. Frantic activity revealed in dusty stellar factories

    Science.gov (United States)

    2009-01-01

    Thanks to the Very Large Telescope's acute and powerful near-infrared eye, astronomers have uncovered a host of new young, massive and dusty stellar nurseries in nearby galaxy NGC 253. The centre of this galaxy appears to harbour a twin of our own Milky Way's supermassive black hole. ESO PR Photo 02a/09 The Spiral Galaxy NGC 253 Astronomers from the Instituto de Astrofísica de Canarias (Spain) used NACO, a sharp-eyed adaptive optics instrument on ESO's Very Large Telescope (VLT), to study the fine detail in NGC 253, one of the brightest and dustiest spiral galaxies in the sky. Adaptive Optics (AO) corrects for the blurring effect introduced by the Earth's atmosphere. This turbulence causes the stars to twinkle in a way that delights poets, but frustrates astronomers, since it smears out the images. With AO in action the telescope can produce images that are as sharp as is theoretically possible, as if the telescope were in space. NACO revealed features in the galaxy that were only 11 light-years across. "Our observations provide us with so much spatially resolved detail that we can, for the first time, compare them with the finest radio maps for this galaxy -- maps that have existed for more than a decade," says Juan Antonio Fernández-Ontiveros, the lead author of the paper reporting the results [1]. Astronomers identified 37 distinct bright regions, a threefold increase on previous results, packed into a tiny region at the core of the galaxy, comprising just one percent of the galaxy's total size. The astronomers combined their NACO images with data from another VLT instrument, VISIR, as well as with images from the NASA/ESA Hubble Space Telescope and radio observations made by the Very Large Array and the Very Large Baseline Interferometer. Combining these observations, taken in different wavelength regimes, provided a clue to the nature of these regions. "We now think that these are probably very active nurseries that contain many stars bursting from their

  8. Microradiometers Reveal Ocean Health, Climate Change

    Science.gov (United States)

    2013-01-01

    When NASA researcher Stanford Hooker is in the field, he pays close attention to color. For Hooker, being in the field means being at sea. On one such research trip to the frigid waters of the Arctic, with a Coast Guard icebreaker looming nearby and the snow-crusted ice shelf a few feet away, Hooker leaned over the edge of his small boat and lowered a tethered device into the bright turquoise water, a new product devised by a NASA partner and enabled by a promising technology for oceanographers and atmospheric scientists alike. Color is a function of light. Pure water is clear, but the variation in color observed during a visit to the beach or a flight along a coastline depends on the water s depth and the constituents in it, how far down the light penetrates and how it is absorbed and scattered by dissolved and suspended material. Hooker cares about ocean color because of what it can reveal about the health of the ocean, and in turn, the health of our planet. "The main thing we are interested in is the productivity of the water," Hooker says. The seawater contains phytoplankton, microscopic plants, which are the food base for the ocean s ecosystems. Changes in the water s properties, whether due to natural seasonal effects or human influence, can lead to problems for delicate ecosystems such as coral reefs. Ocean color can inform researchers about the quantities and distribution of phytoplankton and other materials, providing clues as to how the world ocean is changing. NASA s Coastal Zone Color Scanner, launched in 1978, was the first ocean color instrument flown on a spacecraft. Since then, the Agency s ocean color research capabilities have become increasingly sophisticated with the launch of the SeaWiFS instrument in 1997 and the twin MODIS instruments carried into orbit on NASA s Terra (1999) and Aqua (2002) satellites. The technology provides sweeping, global information on ocean color on a scale unattainable by any other means. One issue that arises from

  9. Image-Aided Navigation Using Cooperative Binocular Stereopsis

    Science.gov (United States)

    2014-03-27

    operating system used is Ubuntu Linux 12.04, running version 3.20-35 of the Linux kernel. The navigation software uses the computer vision library OpenCV ...detector, descriptor extractor, and descriptor matcher objects. OpenCV offers a number of traditional methods, such as SIFT [43] and SURF [6], as well as...conducted prior to each flight using a publicly available ROS camera calibration package. The camera calibration package uses OpenCV camera calibration

  10. Visual Phenomena Produced by Binocularly Disparate Dynamic Visual Noise.

    Science.gov (United States)

    1985-05-01

    measurements were obtained using a haploscope optometer (cf., Ciuffreda & Kenyon, 1983) consisting of two optical channels. Each channel consists of a...optical channel axis for measurement of accommodation. Each channel of the optometer could also be rotated about the center of rotation of the eye (in...are a haploscope optometer , consisting of light sources (SL and SR) , lenses (LL and LR), and beamsplitters (BL and BR), and a movable LED which was

  11. Exploring the Moon through binoculars and small telescopes

    CERN Document Server

    Cherrington, Ernest H

    1984-01-01

    Informative, profusely illustrated guide to locating and identifying craters, rills, seas, mountains, other lunar features. Newly revised and updated with special section of new photos. Over 100 photos and diagrams. ""Extraordinary delight awaits the amateur astronomer or teacher who opens this book."" - The Science Teacher.

  12. Real-Time Gaze Holding in Binocular Robot Vision

    Science.gov (United States)

    1992-06-01

    34A New Approach to Vi- sion and Control for Road Following," NISTIR 4476, National Institute of Standards and Techonology (NIST). Robot Systems...of Rochester Rochester, New York June 1992 Aef"sIOU For /,.’ i"’,.tL~y Codes ,. endlor Special REPORT DOCUMENTATION PAGE Om No.4 0MB No. 07040f189...visual processing) do not execute instantaneously, delays are unavoidable. Suppose the tracking system needs to follow a target that jumps to a new

  13. Manufacturing development of visor for binocular helmet mounted display

    Science.gov (United States)

    Krevor, David; Edwards, Timothy; Larkin, Eric; Skubon, John; Speirs, Robert; Sowden, Tom

    2007-09-01

    The HMD (Helmet Mounted Display) visor is a sophisticated article. It is both the optical combiner for the display and personal protective equipment for the pilot. The visor must have dimensional and optical tolerances commensurate with precision optics; and mechanical properties sufficient for a ballistic shield. Optimized processes and tooling are necessary in order to manufacture a functional visor. This paper describes the manufacturing development of the visor for the Joint Strike Fighter (JSF) HMD. The analytical and experimental basis for the tool and manufacturing process development are described; as well as the metrological and testing methods to verify the visor design and function. The requirements for the F-35 JSF visor are a generation beyond those for the HMD visor which currently flies on the F-15, F-16 and F/A-18. The need for greater precision is manifest in the requirements for the tooling and molding process for the visor. The visor is injection-molded optical polycarbonate, selected for its combination of optical, mechanical and environmental properties. Proper design and manufacture of the tool - the mold - is essential. Design of the manufacturing tooling is an iterative process between visor design, mold design, mechanical modeling and polymer-flow modeling. Iterative design and manufacture enable the mold designer to define a polymer shrinkage factor more precise than derived from modeling or recommended by the resin supplier.

  14. 21 CFR 1.21 - Failure to reveal material facts.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Failure to reveal material facts. 1.21 Section 1... GENERAL ENFORCEMENT REGULATIONS General Labeling Requirements § 1.21 Failure to reveal material facts. (a) Labeling of a food, drug, device, or cosmetic shall be deemed to be misleading if it fails to reveal...

  15. Eliminating Rivals, Managing Rivalries : a Comparison of Robert Mugabe and Kenneth Kaunda

    NARCIS (Netherlands)

    McLoughlin, Stephen; Weerdesteijn, M.

    2016-01-01

    This article seeks to explore the role that leadership plays in both the perpetration and avoidance of mass atrocities. Many scholars have argued that leadership is pivotal to the outbreak of such violence but there is almost no scholarship which explores the role that political leaders play in miti

  16. Examining the TAPI pipeline and its impact on regional and cross-regional rivalry

    OpenAIRE

    FARAJI RAD ABDOL REZA; Moradi, Heydar

    2012-01-01

    Before 1991, the states of Central Asia were marginal backwaters, republics of the Soviet Union that played neither a major role in the Cold War relations between the U.S.S.R. and the United States, nor in the Soviet Union's relations with the principal regional powers of Turkey, Iran, and China. But in the 1990s, the dissolution of the Soviet Union coincided with rediscovery of the energy resources of the Caspian Sea, attracting a wide range of international oil companies, including American...

  17. Brazilian-Argentine Relations in the 1980s: from Wary Rivalry toward Friendly Competition

    Science.gov (United States)

    1985-03-01

    Kingdom 7 Venezuela 27 Arab Countries 6 Frarce 26 Venezuela 6 Mexico 22 Cuba 3 Cuba 19 Mexico 2 Source: Foreign Opinion Note of June 26, 1981, Office...terms from creditors, based on concessions won earlier by the other side. ( Mexico is the third important player in this game.) Formation of a more radical...future are analyzed in Helio Jaguaribe, "Brasil-Argentina: Breve analisis de las relaciones de conflicto y cooperacion," Estudios internacionales

  18. The Strategic Impact Upon the United States of Future Naval Rivalries in South and Southeast Asia

    Science.gov (United States)

    1992-12-01

    understand the rationale surrounding China’s relations with the rest of the world, one must take into account the intense Sinocentrism that has been an...integral part of the Chinese mindset for centuries. "... Sinocentrism was so strong that in the face of a superior military power, China could draw in

  19. Overcoming the Sibling Rivalry: Enhancing Department of Defense Capability to Conduct Joint Expeditionary Warfare

    Science.gov (United States)

    2011-02-16

    joint integration. One of the main efforts of the act was to improve the jointness of the armed services. According to Dr. Richard Meinhart , the...Goldwater-Nichols – Failing to Go the Distance.” Carlisle Barracks: U.S. Army War College, 2008. Hinote, LtCol Clint. Centralized Control and...Barracks: U.S. Army War College, 2007. Peach, Air Commodore Stuart, “The Airmen’s Dilemma to Command or Control,” In Airpower 21: Challenges for the

  20. North-South Rivalry and Offshore Balancing in Sub-Saharan Africa

    DEFF Research Database (Denmark)

    Kluth, Michael Friederich; Pilegaard, Jess

    Sub-Saharan Africa constitutes a distinct security region and hosts a high proportion of fragile and failed states presiding over territories with abundant resources – but no indigenous great powers! Following offensive neorealist logic, the absence of local great powers explains the continued be...

  1. The Rivalry of the French and American Educational Missions during the Vietnam War

    Science.gov (United States)

    Nguyen, Thuy-Phuong

    2014-01-01

    From 1955 to 1975, the French and the Americans were both active in the educational field in South Vietnam, but their objectives were different. The French were concerned with preserving their influence with the Vietnamese elites and relied on the Mission Culturelle--the heir of the colonial Direction of Education--and its prestigious high…

  2. The Saudi-Iranian Rivalry and the Future of Middle East Security

    Science.gov (United States)

    2011-12-01

    Saudi-Syrian relations took a dramatic turn for the worse on February 14, 2005, when former Lebanese Prime Minister Rafiq Hariri and eight of his...tensions created by the feared reaction to the expected indictment of Hezbollah members for the murder of former Prime Minister Rafiq Hariri by the...Lebanese reconstruction. In 1992, pro- Saudi Lebanese billionaire Rafiq al-Hariri became prime minister as a result of the Taif Accords leading to a

  3. Storm over Serbia the rivalry between civilian and military authorities (1911-1914

    Directory of Open Access Journals (Sweden)

    Bataković Dušan T.

    2013-01-01

    Full Text Available As a new force on the political scene of Serbia after the 1903 Coup which brought the Karadjordjević dynasty back to the throne and restored democratic order, the Serbian army, led by a group of conspiring officers, perceived itself as the main guardian of the country’s sovereignty and the principal executor of the sacred mission of national unification of the Serbs, a goal which had been abandoned after the 1878 Berlin Treaty. During the “Golden Age” decade (1903-1914 in the reign of King Peter I, Serbia emerged as a point of strong attraction to the Serbs and other South Slavs in the neighbouring empires and as their potential protector. In 1912-13, Serbia demonstrated her strength by liberating the Serbs in the “unredeemed provinces” of the Ottoman Empire. The main threat to Serbia’s very existence was multinational Austria-Hungary, which thwarted Belgrade’s aspirations at every turn. The Tariff War (1906-1911, the annexation of Bosnia-Herzegovina (1908, and the coercing of Serbia to cede her territorial gains in northern Albania (1912-1913 were but episodes of this fixed policy. In 1991, the Serbian army officers, frustrated by what they considered as weak reaction from domestic political forces and the growing external challenges to Serbia’s independence, formed the secret patriotic organisation “Unification or Death” (Black Hand. Serbian victories in the Balkan Wars (1912-1913 enhanced the prestige of the military but also boosted political ambitions of Lt.-Colonel Dragutin T. Dimitrijević Apis and other founding members of the Black Hand anxious to bring about the change of government. However, the idea of a military putsch limited to Serbian Macedonia proposed in May 1914 was rejected by prominent members of the Black Hand, defunct since 1913. This was a clear indication that Apis and a few others could not find support for their meddling in politics. The government of Nikola P. Pašić, supported by the Regent, Crown Prince Alexander, called for new elections to verify its victory against those military factions that acted as an “irresponsible factor” with “praetorian ambitions” in Serbian politics. This trial of strength brings new and valuable insights into the controversial relationship between the Young Bosnians and the Black Hand prior to the Sarajevo assassination in June 1914. [Projekat Ministarstva nauke Republike Srbije, br. 177011: History of political ideas and institutions in the Balkans in the 19th and 20th centuries

  4. New Patterns of Collaboration and Rivalry in the US and European Defense and Aerospace Industries

    Science.gov (United States)

    2009-08-19

    implications beyond Boeing. It will likely influence how Airbus moves forward on its A320 replacement effort, the A30X. For airlines, it means an even longer...wait until a 737 or A320 follow-on hits the market. For Boeing, the focus now switches to more fundamental research into aerodynamics, composites...the terms included in the Pentagon’s National Industrial Security Program Operating Manual (NISPOM). Created by an executive order in 1995 and

  5. Fundamental Evaluation of Adaptation and Human Capabilities in a Condition Using a System to Give a User an Artificial Oculomotor Function to Control Directions of Both Eyes Independently

    Directory of Open Access Journals (Sweden)

    Fumio Mizuno

    2011-10-01

    Full Text Available To investigate flexible adaptation of visual system, we developed a system to provide a user an artificial oculomotor function to control directions of both eyes. The system named “Virtual Chameleon” consists of two CCD cameras independently controlled and a head-mounted display. The user can control each tracking directions of two cameras with sensors set to both hands so that the user can get independent arbitrary view fields for both eyes. We performed fundamental experiments to evaluate capability to evaluate adaptation to use of Virtual Chameleon and effects on the user's capabilities. Eleven healthy volunteers with normal and corrected-to-normal vision participated in the experiments. The experiments were tests to find out each position of targets put in both side of a subject. In the experiments, a condition using Virtual Chameleon and a condition without it was adopted. We obtained accuracy rates and time intervals to find out target positions as experimental results. The experiments showed all of volunteers became able to actively control independent visual axes and correctly understood two different views by using Virtual Chameleon, even though two independent view fields yielded binocular rivalry to volunteers and binocular rivalry reduced human capabilities compared to cases without Virtual Chameleon.

  6. Short-Term Monocular Deprivation Enhances Physiological Pupillary Oscillations

    Directory of Open Access Journals (Sweden)

    Paola Binda

    2017-01-01

    Full Text Available Short-term monocular deprivation alters visual perception in adult humans, increasing the dominance of the deprived eye, for example, as measured with binocular rivalry. This form of plasticity may depend upon the inhibition/excitation balance in the visual cortex. Recent work suggests that cortical excitability is reliably tracked by dilations and constrictions of the pupils of the eyes. Here, we ask whether monocular deprivation produces a systematic change of pupil behavior, as measured at rest, that is independent of the change of visual perception. During periods of minimal sensory stimulation (in the dark and task requirements (minimizing body and gaze movements, slow pupil oscillations, “hippus,” spontaneously appear. We find that hippus amplitude increases after monocular deprivation, with larger hippus changes in participants showing larger ocular dominance changes (measured by binocular rivalry. This tight correlation suggests that a single latent variable explains both the change of ocular dominance and hippus. We speculate that the neurotransmitter norepinephrine may be implicated in this phenomenon, given its important role in both plasticity and pupil control. On the practical side, our results indicate that measuring the pupil hippus (a simple and short procedure provides a sensitive index of the change of ocular dominance induced by short-term monocular deprivation, hence a proxy for plasticity.

  7. Genome-Wide Scan Reveals Mutation Associated with Melanoma

    Science.gov (United States)

    ... historical) Genome-Wide Scan Reveals Mutation Associated with Melanoma A team of international researchers supported by the ... when they divide and grow uncontrollably, develop into melanoma. Also, MITF activity is known to be amplified ...

  8. ON THE AXIOMS OF REVEALED PREFERENCE IN FUZZY CONSUMER THEORY

    Institute of Scientific and Technical Information of China (English)

    Irina GEORGESCU

    2004-01-01

    The revealed preference is a central subject in classical consumer theory. Authors like Samuelson, Arrow, Richter, Sen, Uzawa and others have proposed an axiomatic setting of revealed preference theory. Consequently revealed preference axioms WARP and SARP and congruence axioms WCA and SCA have been considered. An important theorem of Sen establishes the equivalence between these axioms provided thefamily of budgets includes all non-empty finite sets of bundles. Fuzzy consumer theory (=fuzzy choice functions) is a topic that appears in a lot of papers.Particularly, Banerjee studies in fuzzy context axioms of revealed preference and congruence extending some results of Arrow and Sen. In this paper we modify the Banerjee definition of a fuzzy choice function (=fuzzy consumer)and we study some fuzzy versions of the axioms of revealed preference and congruence. Banerjee fuzzifies only the range of a consumer; we use a fuzzification of both the domain and the range of a consumer. The axioms WAFRP, SAFRP, WFCA, SFCA generalize to fuzzy consumer theory the well-known axioms WARP, SARP, WCA, SCA. Our main result establishes some connections between WAFRP, SAFRP, WFCA, SFCA extending a significant part of Sen theorem. Generally, we work in a fuzzy set theory based on a continuous t-norm, but some results are obtained for Godel t-norm and others are obtained for Lukasiewicz t-norm.

  9. More on Measuring the Overall Revealed Comparative Advantage

    Directory of Open Access Journals (Sweden)

    Veselin Hadzhiev

    2014-11-01

    Full Text Available The overall revealed comparative advantages approach aims to summarize the divergent expression of comparative advantages by commodity groups and countries. It represents an alternative to the traditional approach of Bella Balassa, Thomas Vollrath and others. The innovativeness of the overall revealed comparative advantages approach preconditions a certain prudence with regard to its use and interpretation. It is necessary to explore the potential of the approach in different conditions and different circumstances. It was found that the approach of overall revealed comparative advantages is resistant to the Euclidean distances and commodity classifications used for metrification. It has the potential to synthesize uniformly divergent changes in specialization by country and commodity groups and is a useful tool for the analysis of comparative advantages.

  10. Revealing physical interaction networks from statistics of collective dynamics

    Science.gov (United States)

    Nitzan, Mor; Casadiego, Jose; Timme, Marc

    2017-01-01

    Revealing physical interactions in complex systems from observed collective dynamics constitutes a fundamental inverse problem in science. Current reconstruction methods require access to a system’s model or dynamical data at a level of detail often not available. We exploit changes in invariant measures, in particular distributions of sampled states of the system in response to driving signals, and use compressed sensing to reveal physical interaction networks. Dynamical observations following driving suffice to infer physical connectivity even if they are temporally disordered, are acquired at large sampling intervals, and stem from different experiments. Testing various nonlinear dynamic processes emerging on artificial and real network topologies indicates high reconstruction quality for existence as well as type of interactions. These results advance our ability to reveal physical interaction networks in complex synthetic and natural systems. PMID:28246630

  11. ID-check: Online concealed information test reveals true identity

    NARCIS (Netherlands)

    Verschuere, B.; Kleinberg, B.

    2016-01-01

    The Internet has already changed people's lives considerably and is likely to drastically change forensic research. We developed a web-based test to reveal concealed autobiographical information. Initial studies identified a number of conditions that affect diagnostic efficiency. By combining these

  12. Thrombotic Microangiopathy Revealing Bone Metastases from an Ethmoid Sinus Carcinoma

    Directory of Open Access Journals (Sweden)

    Mony Chenda Morisse

    2016-08-01

    Full Text Available Cancer-related thrombotic microangiopathy (TMA is a rare entity whose clinical and biological characteristics have been described in various tumors. Here we describe the first case of cancer-related TMA revealing diffuse bone metastases from an ethmoid sinus carcinoma.

  13. UTV Expansion Pack: Special-Purpose Rank-Revealing Algorithms

    DEFF Research Database (Denmark)

    Fierro, Ricardo D.; Hansen, Per Christian

    2005-01-01

    This collection of Matlab 7.0 software supplements and complements the package UTV Tools from 1999, and includes implementations of special-purpose rank-revealing algorithms developed since the publication of the original package. We provide algorithms for computing and modifying symmetric rank-r...

  14. Revealing Hanny's Voorwerp : radio observations of IC 2497

    NARCIS (Netherlands)

    Jozsa, G. I. G.; Garrett, M. A.; Oosterloo, T. A.; Rampadarath, H.; Paragi, Z.; van Arkel, H.; Lintott, C.; Keel, W. C.; Schawinski, K.; Edmondson, E.

    2009-01-01

    We present multi-wavelength radio observations in the direction of the spiral galaxy IC 2497 and the neighbouring emission nebula known as "Hanny's Voorwerp". Our WSRT continuum observations at 1.4 GHz and 4.9 GHz reveal the presence of extended emission at the position of the nebulosity, although t

  15. On galaxy spiral arms' nature as revealed by rotation frequencies

    NARCIS (Netherlands)

    Roca-Fabrega, Santi; Valenzuela, Octavio; Figueras, Francesca; Romero-Gomez, Merce; Velazquez, Hector; Antoja Castelltort, Teresa; Pichardo, Barbara

    2013-01-01

    High-resolution N-body simulations using different codes and initial condition techniques reveal two different behaviours for the rotation frequency of transient spiral arms like structures. Whereas unbarred discs present spiral arms nearly corotating with disc particles, strong barred models (bulge

  16. Chemical milling solution reveals stress corrosion cracks in titanium alloy

    Science.gov (United States)

    Braski, D. N.

    1967-01-01

    Solution of hydrogen flouride, hydrogen peroxide, and water reveals hot salt stress corrosion cracks in various titanium alloys. After the surface is rinsed in water, dried, and swabbed with the solution, it can be observed by the naked eye or at low magnification.

  17. Integrated genomics of Mucorales reveals novel therapeutic targets

    Science.gov (United States)

    Mucormycosis is a life-threatening infection caused by Mucorales fungi. We sequenced 30 fungal genomes and performed transcriptomics with three representative Rhizopus and Mucor strains with human airway epithelial cells during fungal invasion to reveal key host and fungal determinants contributing ...

  18. Natural Disasters that Reveal Cracks in Our Social Foundation

    Science.gov (United States)

    Langer, Nieli

    2004-01-01

    The recent deaths of more than 13,000 French elderly in the European heat wave of 2003 revealed cracks in the social foundation of urban communities, here and abroad. The breakdown occurred in community services, neighborhood networks, and governmental agencies that were responsible for warning of impending dangers to at-risk elderly. This paper…

  19. Mitochondrial specialization revealed by single muscle fiber proteomics

    DEFF Research Database (Denmark)

    Schiaffino, S; Reggiani, C; Kostrominova, T Y

    2015-01-01

    We have developed a highly sensitive mass spectrometry-based proteomic workflow to examine the proteome of single muscle fibers. This study revealed significant differences in the mitochondrial proteome of the four major fiber types present in mouse skeletal muscle. Here, we focus on Krebs cycle ...... scavenging capacity to cope with the higher levels of reactive oxygen species production....

  20. Benign Cystic Peritoneal Mesothelioma Revealed by Small Bowel Obstruction.

    Science.gov (United States)

    Bray Madoué, Kaimba; Boniface, Moifo; Annick Laure, Edzimbi; Pierre, Herve

    2016-01-01

    Benign cystic peritoneal mesothelioma is a rare tumor which frequently occurs in women of reproductive age. Abdominal pain associated with pelvic or abdominal mass is the common clinical presentation. We report the case of a 22-year-old woman with a pathological proved benign cystic mesothelioma of the peritoneum revealed by a small bowel obstruction and a painful left-sided pelvic mass with signs of psoitis. Contrast enhanced abdominal CT-scan demonstrated a large pelvic cystic mass with mass effect on rectosigmoid and pelvic organs. The patient underwent surgical removal of the tumor. Pathological examination revealed the diagnosis of benign cystic mesothelioma of the peritoneum. The outcome was excellent with a 12-month recoil.

  1. Intracranial Hemorrhage Revealing Pseudohypoparathyroidism as a Cause of Fahr Syndrome

    Directory of Open Access Journals (Sweden)

    Abhijit Swami

    2011-01-01

    Full Text Available Pseudohypoparathyroidism is an infrequently encountered disease. It is one of the causes of Fahr syndrome which also is a rare clinical entity caused by multiple diseases. A 4-year-old man hospitalized for sudden onset left hemiparesis and hypertension was diagnosed to have right thalamic and midbrain hemorrhage on plain CT scan of the head which also revealed co-existent extensive intracranial calcifications involving the basal ganglia and cerebellum bilaterally. General physical examination revealed features of Albright hereditary osteodystrophy, goitre, hypertension, left hemiparesis, and signs of cerebellar dysfunction. Laboratory findings suggested hypocalcemia, hyperphosphatemia along with high TSH, low FT4, low FT3, and high anti-TPO antibody. Though bilateral intracranial calcifications are usually encountered as an incidental radiological finding in the CT scan of brain, in this case, the patient admitted for thalamic and midbrain hemorrhage was on investigation for associated intracranial calcification, and goitre was also found to have coexisting pseudohypoparathyroidism and autoimmune hypothyroidism.

  2. Maps of random walks on complex networks reveal community structure.

    Science.gov (United States)

    Rosvall, Martin; Bergstrom, Carl T

    2008-01-29

    To comprehend the multipartite organization of large-scale biological and social systems, we introduce an information theoretic approach that reveals community structure in weighted and directed networks. We use the probability flow of random walks on a network as a proxy for information flows in the real system and decompose the network into modules by compressing a description of the probability flow. The result is a map that both simplifies and highlights the regularities in the structure and their relationships. We illustrate the method by making a map of scientific communication as captured in the citation patterns of >6,000 journals. We discover a multicentric organization with fields that vary dramatically in size and degree of integration into the network of science. Along the backbone of the network-including physics, chemistry, molecular biology, and medicine-information flows bidirectionally, but the map reveals a directional pattern of citation from the applied fields to the basic sciences.

  3. Systematic toxicological analysis revealing a rare case of captan ingestion.

    Science.gov (United States)

    Gottzein, Anne K; Musshoff, Frank; Madea, Burkhard

    2013-07-01

    This article presents a case of suicide by intoxication with various pharmaceuticals, particularly anticonvulsants, combined with the fungicide captan. A cause of death could not be ascertained at autopsy. However, systematic toxicological analysis (STA) including a screening via solid-phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) for (semi) volatile organic compounds revealed results suggesting a possible cause of death. The effects of captan on the human organism, its metabolism, and distribution will be discussed. Macroscopically, the cause of death was unascertained. STA revealed clonazepam, citalopram, and its metabolites, lamotrigine, levetiracetam, lacosamide, clonazepam, captan, and its metabolite tetrahydrophthalimide (THPI). For the first time, it was detected in human viscera. A quantification of THPI was performed to obtain distribution in the organs. The significance of a complete STA must be emphasized. The presence of THPI would have been missed without previous detection of captan. Consequently, this fatality would not have been investigated satisfactorily.

  4. Genome Polymorphisms Between Indica and Japonica Revealed by RFLP

    Institute of Scientific and Technical Information of China (English)

    WANG Song-wen; LIU Xia; XU Cai-guo; SHI Li-li; ZHANG Xin; DING De-liang; WANG Yong

    2007-01-01

    Revealing the genome polymorphisms between indica and japonica subspecies; RFLP markers, which are located across 12 chromosomes of rice, were used to analyze indica-japonica differentiation in different rice varieties. At the same time, genome sequence variations of screened loci were analyzed by bioinformatics method. Twenty-eight RFLP probes, which can classify indica-japonica rice, were confirmed. Subspecies genome polymorphisms of screened loci were found by analyzing the publication of the genome sequences data of rice. The study indicated that these screened markers can be used for classifying indica-japonica subspecies. With the publication of the genome sequences of rice, marker polymorphisms between indica and japonica subspecies can be revealed by genome differentiation.

  5. Intracranial hemorrhage revealing pseudohypoparathyroidism as a cause of fahr syndrome.

    Science.gov (United States)

    Swami, Abhijit; Kar, Giridhari

    2011-01-01

    Pseudohypoparathyroidism is an infrequently encountered disease. It is one of the causes of Fahr syndrome which also is a rare clinical entity caused by multiple diseases. A 4-year-old man hospitalized for sudden onset left hemiparesis and hypertension was diagnosed to have right thalamic and midbrain hemorrhage on plain CT scan of the head which also revealed co-existent extensive intracranial calcifications involving the basal ganglia and cerebellum bilaterally. General physical examination revealed features of Albright hereditary osteodystrophy, goitre, hypertension, left hemiparesis, and signs of cerebellar dysfunction. Laboratory findings suggested hypocalcemia, hyperphosphatemia along with high TSH, low FT(4), low FT(3), and high anti-TPO antibody. Though bilateral intracranial calcifications are usually encountered as an incidental radiological finding in the CT scan of brain, in this case, the patient admitted for thalamic and midbrain hemorrhage was on investigation for associated intracranial calcification, and goitre was also found to have coexisting pseudohypoparathyroidism and autoimmune hypothyroidism.

  6. Acting without seeing: eye movements reveal visual processing without awareness.

    Science.gov (United States)

    Spering, Miriam; Carrasco, Marisa

    2015-04-01

    Visual perception and eye movements are considered to be tightly linked. Diverse fields, ranging from developmental psychology to computer science, utilize eye tracking to measure visual perception. However, this prevailing view has been challenged by recent behavioral studies. Here, we review converging evidence revealing dissociations between the contents of perceptual awareness and different types of eye movement. Such dissociations reveal situations in which eye movements are sensitive to particular visual features that fail to modulate perceptual reports. We also discuss neurophysiological, neuroimaging, and clinical studies supporting the role of subcortical pathways for visual processing without awareness. Our review links awareness to perceptual-eye movement dissociations and furthers our understanding of the brain pathways underlying vision and movement with and without awareness.

  7. Revealing Children's Experiences and Emotions through Q Methodology

    OpenAIRE

    Ingunn T. Ellingsen; Arlene Arstad Thorsen; Ingunn Størksen

    2014-01-01

    Over the last two decades, there has been a greater readiness to view children as competent contributors to our understanding of children’s lives and experiences. As a consequence of this, we have witnessed an increased focus on including children in research. When research aims at revealing children’s perspectives, experiences, and emotions, we need to employ methods that are easy-to-use means for obtaining their stories. In this paper, we argue that Q methodology is particularly suitable fo...

  8. Monofractal nature of air temperature signals reveals their climate variability

    OpenAIRE

    Deliège, Adrien; Nicolay, Samuel

    2014-01-01

    We use the discrete "wavelet transform microscope" to show that the surface air temperature signals of weather stations selected in Europe are monofractal. This study reveals that the information obtained in this way are richer than previous works studying long range correlations in meteorological stations. The approach presented here allows to bind the H\\"older exponents with the climate variability. We also establish that such a link does not exist with methods previously carried out.

  9. Dermatomyositis revealing breast cancer: report of a case.

    Science.gov (United States)

    Lamquami, Safae; Errarhay, Sanae; Mamouni, Nisrine; Bouchikhi, Chahrazad; Banani, Abdelaziz

    2015-01-01

    Dermatomyositis (DM) is a rare connective corresponding to an inflammatory disease of skeletal muscles. Paraneoplastic origin must always be sought, primarily gynecological tumor in women, but the investigations are often made difficult by the fact that a primary tumor is often not detectable at the time of the cutaneous manifestations. This approach includes in addition to the monitoring report at regular intervals of 6 to 12 months for two years after diagnosis. We report a case of Dermatomyositis revealing breast cancer.

  10. Transcriptome Reveals Cathepsin K in Periodontal Ligament Differentiation.

    Science.gov (United States)

    Yamada, S; Ozaki, N; Tsushima, K; Yamaba, S; Fujihara, C; Awata, T; Sakashita, H; Kajikawa, T; Kitagaki, J; Yamashita, M; Yanagita, M; Murakami, S

    2016-08-01

    Periodontal ligaments (PDLs) play an important role in remodeling the alveolar bond and cementum. Characterization of the periodontal tissue transcriptome remains incomplete, and an improved understanding of PDL features could aid in developing new regenerative therapies. Here, we aimed to generate and analyze a large human PDL transcriptome. We obtained PDLs from orthodontic treatment patients, isolated the RNA, and used a vector-capping method to make a complementary DNA library from >20,000 clones. Our results revealed that 58% of the sequences were full length. Furthermore, our analysis showed that genes expressed at the highest frequencies included those for collagen type I, collagen type III, and proteases. We also found 5 genes whose expressions have not been previously reported in human PDL. To access which of the highly expressed genes might be important for PDL cell differentiation, we used real-time polymerase chain reaction to measure their expression in differentiating cells. Among the genes tested, the cysteine protease cathepsin K had the highest upregulation, so we measured its relative expression in several tissues, as well as in osteoclasts, which are known to express high levels of cathepsin K. Our results revealed that PDL cells express cathepsin K at similar levels as osteoclasts, which are both expressed at higher levels than those of the other tissues tested. We also measured cathepsin K protein expression and enzyme activity during cell differentiation and found that both increased during this process. Immunocytochemistry experiments revealed that cathepsin K localizes to the interior of lysosomes. Last, we examined the effect of inhibiting cathepsin K during cell differentiation and found that cathepsin K inhibition stimulated calcified nodule formation and increased the levels of collagen type I and osteocalcin gene expression. Based on these results, cathepsin K seems to regulate collagen fiber accumulation during human PDL cell

  11. Genes but not genomes reveal bacterial domestication of Lactococcus lactis.

    Directory of Open Access Journals (Sweden)

    Delphine Passerini

    Full Text Available BACKGROUND: The population structure and diversity of Lactococcus lactis subsp. lactis, a major industrial bacterium involved in milk fermentation, was determined at both gene and genome level. Seventy-six lactococcal isolates of various origins were studied by different genotyping methods and thirty-six strains displaying unique macrorestriction fingerprints were analyzed by a new multilocus sequence typing (MLST scheme. This gene-based analysis was compared to genomic characteristics determined by pulsed-field gel electrophoresis (PFGE. METHODOLOGY/PRINCIPAL FINDINGS: The MLST analysis revealed that L. lactis subsp. lactis is essentially clonal with infrequent intra- and intergenic recombination; also, despite its taxonomical classification as a subspecies, it displays a genetic diversity as substantial as that within several other bacterial species. Genome-based analysis revealed a genome size variability of 20%, a value typical of bacteria inhabiting different ecological niches, and that suggests a large pan-genome for this subspecies. However, the genomic characteristics (macrorestriction pattern, genome or chromosome size, plasmid content did not correlate to the MLST-based phylogeny, with strains from the same sequence type (ST differing by up to 230 kb in genome size. CONCLUSION/SIGNIFICANCE: The gene-based phylogeny was not fully consistent with the traditional classification into dairy and non-dairy strains but supported a new classification based on ecological separation between "environmental" strains, the main contributors to the genetic diversity within the subspecies, and "domesticated" strains, subject to recent genetic bottlenecks. Comparison between gene- and genome-based analyses revealed little relationship between core and dispensable genome phylogenies, indicating that clonal diversification and phenotypic variability of the "domesticated" strains essentially arose through substantial genomic flux within the dispensable

  12. Revealing and Characterizing Dark Excitons Through Coherent Multidimensional Spectroscopy

    CERN Document Server

    Tollerud, Jonathan O; Davis, Jeffrey A

    2016-01-01

    Dark excitons are of fundamental importance in a broad range of contexts, but are difficult to study using conventional optical spectroscopy due to their weak interaction with light. We show how coherent multidimensional spectroscopy can reveal and characterize dark states. Using this approach, we identify different types of dark excitons in InGaAs/GaAs quantum wells and determine details regarding lifetimes, homogeneous and inhomogeneous linewidths, broadening mechanisms and coupling strengths. The observations of coherent coupling between bright and dark excitons hint at a role for a multi-step process by which excitons in the barrier can relax into the quantum wells.

  13. How the ``Blues'' reveals the intimacy of music and physics

    Science.gov (United States)

    Gibson, J. Murray

    2013-03-01

    Little do most people know when they hear blues piano - and you'll hear some live in this talk - that physics permeates the style, as it does all of music. Why should you care? By deconstructing blues piano the intimacy of physics, mathematics and music will be revealed in its glory.[1] The exercise says something about how the brains of the music composer and of the listener must be intimately linked to the physical principles of acoustics. And it provides a great vehicle to explain physical phenomena to non-scientists - everything from quantum mechanics to protein structure.

  14. Mediated amperometry reveals different modes of yeast responses to sugars.

    Science.gov (United States)

    Garjonyte, Rasa; Melvydas, Vytautas; Malinauskas, Albertas

    2016-02-01

    Menadione-mediated amperometry at carbon paste electrodes modified with various yeasts (Saccharomyces cerevisiae, Candida pulcherrima, Pichia guilliermondii and Debaryomyces hansenii) was employed to monitor redox activity inside the yeast cells induced by glucose, fructose, sucrose, maltose or galactose. Continuous measurements revealed distinct modes (transient or gradually increasing) of the current development during the first 2 to 3 min after subjection to glucose, fructose and sucrose at electrodes containing S. cerevisiae and non-Saccharomyces strains. Different modes (increasing or decreasing) of the current development after yeast subjection to galactose at electrodes with S. cerevisiae or D. hansenii and at electrodes with C. pulcherrima and P. guilliermondii suggested different mechanisms of galactose assimilation.

  15. Malar Bone Metastasis Revealing a Papillary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Ihsen Slim

    2012-01-01

    Full Text Available Papillary thyroid carcinoma is the most common form of differentiated thyroid carcinoma. It is generally confined to the neck with or without spread to regional lymph nodes. Metastatic thyroid carcinomas are uncommon and mainly include lung and bone. Metastases involving oral and maxillofacial region are extremely rare. We described a case of malar metastasis revealing a follicular variant of papillary thyroid carcinoma, presenting with pain and swelling of the left cheek in a 67-years-old female patient with an unspecified histological left lobo-isthmectomy medical history. To our knowledge, this is the first recorded instance of a malar metastasis from a follicular variant of papillary thyroid carcinoma.

  16. Windows PowerShell desired state configuration revealed

    CERN Document Server

    Chaganti, Ravikanth

    2014-01-01

    Desired State Configuration (DSC) is a powerful new configuration management platform that makes it easier than ever to perform cross-platform configuration management of your infrastructure, whether on-premise or in the cloud. DSC provides the management platform and Application Programming Interface (API) that can be used with any programming language. Windows PowerShell Desired State Configuration Revealed will take you through this new technology from start to finish and demonstrates the DSC interfaces through Windows PowerShell. DSC allows you to manage target devices by simply declarin

  17. Circumstellar Environments of MYSOs Revealed by IFU Spectroscopy

    Science.gov (United States)

    Navarete, F.; Damineli, A.; Barbosa, C. L.; Blum, R. D.

    2015-01-01

    Formation of massive stars (M > 8 M ⊙) is still not well understood and lacks of observational constraints. We observed 7 MYSO candidates using the NIFS spectrometer at Gemini North Telescope to study the accretion process at high angular resolution (~ 50 mas) and very closer to the central star. Preliminary results for 2 sources have revealed circumstellar structures traced by Brackett-Gamma, CO lines and extended H2 emission. Both sources present kinematics in the CO absorption lines, suggesting rotating structures. The next step will derive the central mass of each source by applying a keplerian model for these CO features.

  18. Planck revealed bulk motion of Centaurus A lobes

    CERN Document Server

    De Paolis, F; Nucita, A A; Ingrosso, G; Kashin, A L; Khachatryan, H G; Mirzoyan, S; Yegorian, G; Jetzer, Ph; Qadir, A; Vetrugno, D

    2015-01-01

    Planck data towards the active galaxy Centaurus A are analyzed in the 70, 100 and 143 GHz bands. We find a temperature asymmetry of the northern radio lobe with respect to the southern one that clearly extends at least up to 5 degrees from the Cen A center and diminishes towards the outer regions of the lobes. That transparent parameter - the temperature asymmetry - thus has to carry a principal information, i.e. indication on the line-of-sight bulk motion of the lobes, while the increase of that asymmetry at smaller radii reveals the differential dynamics of the lobes as expected at ejections from the center.

  19. Linear stability analysis reveals exclusion zone for sliding bed transport

    Directory of Open Access Journals (Sweden)

    Talmon Arnold M.

    2015-06-01

    Full Text Available A bend or any another pipe component disturbs solids transport in pipes. Longitudinal pressure profiles downstream of such a component may show a stationary transient harmonic wave, as revealed by a recent settling slurry laboratory experiment. Therefore the fundamental transient response of the two-layer model for fully stratified flow is investigated as a first approach. A linear stability analysis of the sliding bed configuration is conducted. No stationary transient harmonic waves are found in this analysis, but adaptation lengths for exponential recovery are quantified. An example calculation is given for a 0.1 m diameter pipeline.

  20. IVT-seq reveals extreme bias in RNA sequencing

    OpenAIRE

    Kavaklı, Halil; Lahens, Nicholas F.; Zhang, Ray; Hayer, Katharina; Black, Michael B.; Dueck, Hannah; Pizarro, Angel; Kim, Junhyong; Irizarry, Rafael; Thomas, Russell S.; Grant, Gregory R.; Hogenesch, John B.

    2014-01-01

    RESEARCH Open Access IVT-seq reveals extreme bias in RNA sequencing Nicholas F Lahens1, Ibrahim Halil Kavakli2,3, Ray Zhang1, Katharina Hayer4, Michael B Black5, Hannah Dueck6, Angel Pizarro7, Junhyong Kim6, Rafael Irizarry8, Russell S Thomas5, Gregory R Grant4,9 and John B Hogenesch1* Abstract Background: RNA-seq is a powerful technique for identifying and quantifying transcription and splicing events, both known and novel. However, given its recent development and the prol...