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Sample records for afferent visual system

  1. Anatomy and physiology of the afferent visual system.

    Science.gov (United States)

    Prasad, Sashank; Galetta, Steven L

    2011-01-01

    The efficient organization of the human afferent visual system meets enormous computational challenges. Once visual information is received by the eye, the signal is relayed by the retina, optic nerve, chiasm, tracts, lateral geniculate nucleus, and optic radiations to the striate cortex and extrastriate association cortices for final visual processing. At each stage, the functional organization of these circuits is derived from their anatomical and structural relationships. In the retina, photoreceptors convert photons of light to an electrochemical signal that is relayed to retinal ganglion cells. Ganglion cell axons course through the optic nerve, and their partial decussation in the chiasm brings together corresponding inputs from each eye. Some inputs follow pathways to mediate pupil light reflexes and circadian rhythms. However, the majority of inputs arrive at the lateral geniculate nucleus, which relays visual information via second-order neurons that course through the optic radiations to arrive in striate cortex. Feedback mechanisms from higher cortical areas shape the neuronal responses in early visual areas, supporting coherent visual perception. Detailed knowledge of the anatomy of the afferent visual system, in combination with skilled examination, allows precise localization of neuropathological processes and guides effective diagnosis and management of neuro-ophthalmic disorders.

  2. Extraocular muscle afferent signals modulate visual attention.

    Science.gov (United States)

    Balslev, Daniela; Newman, William; Knox, Paul C

    2012-10-09

    Extraocular muscle afferent signals contribute to oculomotor control and visual localization. Prompted by the close links between the oculomotor and attention systems, it was investigated whether these proprioceptive signals also modulated the allocation of attention in space. A suction sclera contact lens was used to impose an eye rotation on the nonviewing, dominant eye. With their viewing, nondominant eye, participants (n = 4) fixated centrally and detected targets presented at 5° in the left or right visual hemifield. The position of the viewing eye was monitored throughout the experiment. As a control, visual localization was tested using finger pointing without visual feedback of the hand, whereas the nonviewing eye remained deviated. The sustained passive rotation of the occluded, dominant eye, while the other eye maintained central fixation, resulted in a lateralized change in the detectability of visual targets. In all participants, the advantage in speed and accuracy for detecting right versus left hemifield targets that occurred during a sustained rightward eye rotation of the dominant eye was reduced or reversed by a leftward eye rotation. The control experiment confirmed that the eye deviation procedure caused pointing errors consistent with an approximately 2° shift in perceived eye position, in the direction of rotation of the nonviewing eye. With the caveat of the small number of participants, these results suggest that extraocular muscle afferent signals modulate the deployment of attention in visual space.

  3. Distinct recurrent versus afferent dynamics in cortical visual processing.

    Science.gov (United States)

    Reinhold, Kimberly; Lien, Anthony D; Scanziani, Massimo

    2015-12-01

    How intracortical recurrent circuits in mammalian sensory cortex influence dynamics of sensory representation is not understood. Previous methods could not distinguish the relative contributions of recurrent circuits and thalamic afferents to cortical dynamics. We accomplish this by optogenetically manipulating thalamus and cortex. Over the initial 40 ms of visual stimulation, excitation from recurrent circuits in visual cortex progressively increased to exceed direct thalamocortical excitation. Even when recurrent excitation exceeded thalamic excitation, upon silencing thalamus, sensory-evoked activity in cortex decayed rapidly, with a time constant of 10 ms, which is similar to a neuron's integration time window. In awake mice, this cortical decay function predicted the time-locking of cortical activity to thalamic input at frequencies thalamocortical synapses disrupted the fidelity of sensory transmission. Thus, we determine dynamics intrinsic to cortical recurrent circuits that transform afferent input in time.

  4. Afferent visual pathways in multiple sclerosis: a review.

    Science.gov (United States)

    Graham, Stuart L; Klistorner, Alexander

    2017-01-01

    Multiple sclerosis (MS) is a disease of the central nervous system that involves inflammation and demyelination at multiple sites and causes a wide variety of clinical presentations with variable neurological deficits. The visual pathways are frequently involved with either visual or motor dysfunction. Optic neuritis (ON) is one the most common and best characterized presentations of the disease, but there are many other manifestations depending on the site of the lesion. Eyes that have never had ON show slow progressive loss of axons and retinal ganglion cells. Previously unrecognized optic radiation lesions may be associated with residual latency delays on visual evoked potentials. Both anterograde and retrograde degeneration may occur along the visual pathway. This review covers the features of MS in the anterior and posterior visual system and describes advances that have been made with newer techniques such as retinal optical coherence tomography (OCT), magnetic resonance imaging (MRI) with diffusion tensor imaging and probabilistic tractography (DTI) and multifocal visual evoked potentials (mfVEPs). We report on the inter-relationship between these measures of structure and function, and how they may be used as biomarkers for the disease. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  5. Is human muscle spindle afference dependent on perceived size of error in visual tracking?

    Science.gov (United States)

    Kakuda, N; Wessberg, J; Vallbo, A B

    1997-04-01

    Impulses of 16 muscle spindle afferents from finger extensor muscles were recorded from the radial nerve along with electromyographic (EMG) activity and kinematics of joint movement. Twelve units were classified as Ia and 4 as II spindle afferents. Subjects were requested to perform precision movements at a single metacarpophalangeal joint in an indirect visual tracking task. Similar movements were executed under two different conditions, i.e. with high and low error gain. The purpose was to explore whether different precision demands were associated with different spindle firing rates. With high error gain, a small but significantly higher impulse rate was found in pooled data from Ia afferents during lengthening movements but not during shortening movements, nor with II afferents. EMG was also significantly higher with high error gain in recordings with Ia afferents. When the effect of EMG was factored out, using partial correlation analysis, the significant difference in Ia firing rate vanished. The findings suggest that fusimotor drive as well as skeletomotor activity were both marginally higher when the precision demand was higher, whereas no indication of independent fusimotor adjustments was found. These results are discussed with respect to data from behaving animals and the role of fusimotor independence in various limb muscles proposed.

  6. Afferent Visual Pathway Affection in Patients with PMP22 Deletion-Related Hereditary Neuropathy with Liability to Pressure Palsies

    Science.gov (United States)

    Rinnenthal, Jan Leo; Zimmermann, Hanna; Mikolajczak, Janine; Oberwahrenbrock, Timm; Papazoglou, Sebastian; Pfüller, Caspar F.; Schinzel, Johann; Tackenberg, Björn; Paul, Friedemann; Hahn, Katrin; Bellmann-Strobl, Judith

    2016-01-01

    Background The PMP22 gene encodes a protein integral to peripheral myelin. Its deletion leads to hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is not expressed in the adult central nervous system, but previous studies suggest a role in CNS myelin development. The objective of this study was to identify potential structural and functional alterations in the afferent visual system in HNPP patients. Methods Twenty HNPP patients and 18 matched healthy controls (HC) were recruited in a cross-sectional study. Participants underwent neurological examination including visual acuity, visual evoked potential (VEP) examination, optical coherence tomography (OCT), and magnetic resonance imaging with calculation of brain atrophy, regarding grey and white matter, and voxel based morphometry (VBM), in addition answered the National Eye Institute’s 39-item Visual Functioning Questionnaire (NEI-VFQ). Thirteen patients and 6 HC were additionally examined with magnetic resonance spectroscopy (MRS). Results All patients had normal visual acuity, but reported reduced peripheral vision in comparison to HC in the NEI-VFQ (p = 0.036). VEP latency was prolonged in patients (P100 = 103.7±5.7 ms) in comparison to healthy subjects (P100 = 99.7±4.2 ms, p = 0.007). In OCT, peripapillary retinal nerve fiber layer thickness RNFL was decreased in the nasal sector (90.0±15.5 vs. 101.8±16.5, p = 0.013), and lower nasal sector RNFL correlated with prolonged VEP latency (Rho = -0.405, p = 0.012). MRS revealed reduced tNAA (731.4±45.4 vs. 814.9±62.1, p = 0.017) and tCr (373.8±22.2 vs. 418.7±31.1, p = 0.002) in the visual cortex in patients vs. HC. Whole brain volume, grey and white matter volume, VBM and metabolites in a MRS sensory cortex control voxel did not differ significantly between patients and HC. Conclusion PMP22 deletion leads to functional, metabolic and macro-structural alterations in the afferent visual system of HNPP patients. Our data suggest a

  7. Afferent and efferent pathways in the visual system of the freshwater snail Planorbarius corneus%淡水蜗牛视觉系统的输入与输出通路

    Institute of Scientific and Technical Information of China (English)

    Oksana P Tuchina; Valery V Zhukov; Victor Benno Meyer-Rochow

    2011-01-01

    Afferent and efferent neural elements of the retina and central ganglia in the freshwater snail Planorbarius corneus were labelled using retrograde transport of neurobiotin through the optic nerve.Axons of at least some photoreceptor cells become direct contributors to the optic nerve as no synaptic junctions could be detected.The processes enter the cerebral ganglion and form a dense bundle of thin afferent fibres,the so-called optical neuropil.Efferent neurons were revealed in all ganglia,except the buccal ones.Some of the ascending axons branch in the cerebral ganglia,cross the cerebro-cerebral commissure,reach the contralateral eye and form arborizations in the eye cup.Some efferent neurons send axons to different peripheral nerves as well:n.n.intestinalis,pallialis dexter,pallialis sinister internus et externus.Serotonin- and FMRF-amide-ergic fibres were revealed in the optic nerve.These fibres belong to those central neurons which send their axons to the ipsilateral eye only.They form abundant varicoses in the eye cup and nuclear layer of the retina,and possibly help to regulate retinal sensitivity to light.%通过神经生物素在视神经上的逆行性传输对淡水蜗牛(Planorbarius corneus)视网膜及中央神经节的输入、输出神经元进行标记.由于没有发现突触联系,所以至少一部分光感受细胞的轴突可被视为直接参与形成视神经.这些神经元的轴突进入大脑神经节形成密集的细传入神经纤维束-视神经堆.传出神经元则存在于除颊部以外的所有神经节.一些上行轴突在大脑神经节处分叉,通过脑-脑联合,到达对侧眼并在眼杯处形成分枝.部分传出神经元的轴突也投射于不同的外周神经,如:n.n.intestinalis,pallialis dexter,pallialis sinister internus et externus.五羟色胺能纤维和FMRF-酰胺能纤维均存在于视神经上,且这些纤维隶属于只投射在同侧眼的中央神经元.它们形成了位于眼杯处的丰富曲张结

  8. Stereotaxic coordinates for the Rhesus monkey thalamus and mesencephalon referencing visual afferents and cytoarchitecture.

    Science.gov (United States)

    Benevento, L A

    1975-01-01

    When using a stereotaxic instrument for visual field stimulation we found that electrode placements in the thalamus and mesencephalon of prone rhesus monkeys with the aid of avaiable atlases showed considerable errors. As these animals are valuable for primate visual system reseach an atlas was constructed with methods that have not been used before for rhesus. In addition, the specific connections from the visual cortices, superior colliculus and retina to the thalamus and mesencephalon are also shown. Anesthetized monkeys of specific body dimensions had a matrix of pins inserted into the brain before fixation. A matrix was used so that the penetrations seen in the sectioned brain could be cross related as a control for accurate measurements of the stereotaxic planes throughout the brain. The surface of the whole brain frozen blocks were photographed on the microtome just before a cut section was taken. These calibrated pictures formed the "floor plan" of the atlas as they represent more accurately the brain geometry than individual sections which are distorted by cutting, staining and mounting. Cytoarchitectural (Nissl stain) and axonal connectional (Fink-Heimer stain) information was transferred and adjusted onto the block pictures from their corresponding stained sections. Follow up experiments showed that the present coordinates are accurate for these monkeys of restricted body dimensions. In addition, referencing visual axonal projections onto the same cytoarchitectural map in stereotaxic coordinates provides an atlas for localizing areas of the thalamus, on a basis other than cytoarchitecture, which receive combinations of visual inputs for further anatomical and physiological studies of the rhesus monkey visual system. The atlas further demonstrates that projections do not necessarily follow the cytoarchitectural definition of an area, but rather redefine the thalamus on the basis of specific axonal connections.

  9. Unmyelinated afferents constitute a second system coding tactile stimuli of the human hairy skin.

    Science.gov (United States)

    Vallbo, A B; Olausson, H; Wessberg, J

    1999-06-01

    Impulses were recorded from unmyelinated afferents innervating the forearm skin of human subjects using the technique of microneurography. Units responding to innocuous skin deformation were selected. The sample (n = 38) was split into low-threshold units (n = 27) and high-threshold units (n = 11) on the basis of three distinctive features, i.e., thresholds to skin deformation, size of response to innocuous skin deformation, and differential response to sharp and blunt stimuli. The low-threshold units provisionally were denoted tactile afferents on the basis of their response properties, which strongly suggest that they are coding some feature of tactile stimuli. They exhibited, in many respects, similar functional properties as described for low-threshold C-mechanoreceptive units in other mammals. However, a delayed acceleration, not previously demonstrated, was observed in response to long-lasting innocuous indentations. It was concluded that human hairy skin is innervated by a system of highly sensitive mechanoreceptive units with unmyelinated afferents akin to the system previously described in other mammals. The confirmation that the system is present in the forearm skin and not only in the face area where it first was identified suggests a largely general distribution although there are indications that the tactile C afferents may be lacking in the very distal parts of the limbs. The functional role of the system remains to be assessed although physiological properties of the sense organs invite to speculations that the slow tactile system might have closer relations to limbic functions than to cognitive and motor functions.

  10. Modeling the Afferent Dynamics of the Baroreflex Control System

    DEFF Research Database (Denmark)

    Ottesen, Johnny T.; Mahdi, Adam; Sturdy, Jacob

    2013-01-01

    of mechanoreceptors located in the BR nerve-endings, and modulation of the action potential frequency. The three sub-systems are modeled individually following well-established biological principles. The first submodel, predicting arterial wall deformation, uses blood pressure as an input and outputs circumferential...

  11. Modeling the afferent dynamics of the baroreflex control system.

    Directory of Open Access Journals (Sweden)

    Adam Mahdi

    Full Text Available In this study we develop a modeling framework for predicting baroreceptor firing rate as a function of blood pressure. We test models within this framework both quantitatively and qualitatively using data from rats. The models describe three components: arterial wall deformation, stimulation of mechanoreceptors located in the BR nerve-endings, and modulation of the action potential frequency. The three sub-systems are modeled individually following well-established biological principles. The first submodel, predicting arterial wall deformation, uses blood pressure as an input and outputs circumferential strain. The mechanoreceptor stimulation model, uses circumferential strain as an input, predicting receptor deformation as an output. Finally, the neural model takes receptor deformation as an input predicting the BR firing rate as an output. Our results show that nonlinear dependence of firing rate on pressure can be accounted for by taking into account the nonlinear elastic properties of the artery wall. This was observed when testing the models using multiple experiments with a single set of parameters. We find that to model the response to a square pressure stimulus, giving rise to post-excitatory depression, it is necessary to include an integrate-and-fire model, which allows the firing rate to cease when the stimulus falls below a given threshold. We show that our modeling framework in combination with sensitivity analysis and parameter estimation can be used to test and compare models. Finally, we demonstrate that our preferred model can exhibit all known dynamics and that it is advantageous to combine qualitative and quantitative analysis methods.

  12. THE ROLE OF BRAIN-STEM DISCENDING INHIBITORY SYSTEM IN THE ANTINOCICEPTIVE EFFECT ELICITED BY MUSCLE SPINDLE AFFERENTS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To analyse the antinociceptive effect of muscle spindle afferents and the involved mechanism.Methods The single unit of wide dynamic range(WDR) neurons in the spinal cord dorsal horn were recorded extracelluarly.The effects of muscle spindle afferents elicited by intravenous administration of succinylcholine (Sch) on nociceptive responses (C-fibres-evoked responses,C-responses) of WDR neurons were observed before and after bilateral lesions of ventrolateral periaqueduct gray (PAG).And the effects of muscle spindle afferents on the spontaneous discharge of the tail-flick related cell in the rostral ventro medial medulla (RVM) and on the spontaneous discharge of the PAG neurons were observed.Results The C-responses of WDR neurons were significantly inhibited by muscle spindle afferents,and the inhibitory effects were reduced by bilateral lesions of ventrolateral PAG.The spontaneous discharge of the off-cell in the RVM was excited while the on-cell was inhibited by intravenous administration of Sch.The spontaneous discharge of the PAG neurons were excited by muscle spindle afferents.Conclusion Muscle spindle afferents show a distinct effect of antinociception.PAG-RVM descending inhibitory system may play an important role in this nociceptive modulative mechanism.

  13. Whole-Brain Monosynaptic Afferent Inputs to Basal Forebrain Cholinergic System

    Science.gov (United States)

    Hu, Rongfeng; Jin, Sen; He, Xiaobin; Xu, Fuqiang; Hu, Ji

    2016-01-01

    The basal forebrain cholinergic system (BFCS) robustly modulates many important behaviors, such as arousal, attention, learning and memory, through heavy projections to cortex and hippocampus. However, the presynaptic partners governing BFCS activity still remain poorly understood. Here, we utilized a recently developed rabies virus-based cell-type-specific retrograde tracing system to map the whole-brain afferent inputs of the BFCS. We found that the BFCS receives inputs from multiple cortical areas, such as orbital frontal cortex, motor cortex, and insular cortex, and that the BFCS also receives dense inputs from several subcortical nuclei related to motivation and stress, including lateral septum, central amygdala, paraventricular nucleus of hypothalamus, dorsal raphe, and parabrachial nucleus. Interestingly, we found that the BFCS receives inputs from the olfactory areas and the entorhinal–hippocampal system. These results greatly expand our knowledge about the connectivity of the mouse BFCS and provided important preliminary indications for future exploration of circuit function. PMID:27777554

  14. The Visual System

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    Full Text Available ... Training and Jobs Fellowships NEI Summer Intern Program Diversity In Vision Research & Ophthalmology (DIVRO) Student Training Programs ... The Visual System Ever wonder how your eyes work? Watch this video to learn how you’re ...

  15. The Visual System

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    Full Text Available ... Vision About the Eye Ask a Scientist Video Series Glossary The Visual System Your Eyes’ Natural Defenses ... On average, you blink about 15 to 20 times every minute. That’s up to 28,800 times ...

  16. The Visual System

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  17. The Visual System

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  18. The Visual System

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  19. The Visual System

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  20. Effects of electrical and natural stimulation of skin afferents on the gamma-spindle system of the triceps surae muscle.

    Science.gov (United States)

    Johansson, H; Sjölander, P; Sojka, P; Wadell, I

    1989-08-01

    The aim of the present study was to investigate the extent to which skin receptors might influence the responses of primary muscle spindle afferents via reflex actions on the fusimotor system. The experiments were performed on 43 cats anaesthetized with alpha-chloralose. The alterations in fusimotor activity were assessed from changes in the responses of the muscle spindle afferents to sinusoidal stretching of their parent muscles (triceps surae and plantaris). The mean rate of firing and the modulation of the afferent response were determined. Control measurements were made in absence of any cutaneous stimulation. Tests were made (a) during physiological stimulation of skin afferents of the ipsilateral pad or of the contralateral hindlimb, or (b) during repetitive electrical stimulation of the sural nerve in the ipsilateral hindlimb, or of sural or superficial peroneal nerve in the contralateral hindlimb. Of the total number of 113 units tested with repetitive electrical stimulation of the ipsilateral sural nerve (at 20 Hz), 24.8% exhibited predominantly dynamic fusimotor reflexes, 5.3% mixed or predominantly static fusimotor reflexes. One unit studied in a preparation with intact spinal cord exhibited static reflexes at low stimulation intensities and dynamic ones at higher stimulation strengths. The remaining units (69%) were uninfluenced. When the receptor-bearing muscle was held at constant length and a train of stimuli (at 20 Hz) was applied to the ipsilateral sural nerve, the action potentials in the primary muscle spindle afferent could be stimulus-locked to the 3rd or 4th pulse in the train (and to the pulses following thereafter), with a latency of about 24 ms from the effective pulse. This 1:1 pattern of driving seemed to be mediated via static and/or dynamic fusimotor neurons. Natural stimulation influenced comparatively few units (3 of 65 units tested from the ipsilateral pad and 10 of 98 tested from the contralateral hindlimb), but when the effects

  1. Mechanistic relationship between the vagal afferent pathway, central nervous system and peripheral organs in appetite regulation

    National Research Council Canada - National Science Library

    Ueno, Hiroaki; Nakazato, Masamitsu

    2016-01-01

    .... Of such peptides, gut peptides are known to bind to receptors at the vagal afferent pathway terminal that extend into the mucosal layer of the digestive tract, modulate the electrical activity...

  2. Identified proprioceptive afferents and motor rhythm entrainment in the crayfish walking system.

    Science.gov (United States)

    Elson, R C; Sillar, K T; Bush, B M

    1992-03-01

    1. In crayfish, Pacifastacus leniusculus, remotion of a walking leg stretches the thoraco-coxal (TC) muscle receptor organ (TCMRO), located at the leg's articulation with the thorax. In vitro, alternate stretch and release of the fourth leg's TCMRO entrained the centrally generated rhythmic motor output to that leg, with the remotor phase of the rhythm entraining to TCMRO stretch, the promoter phase to release. This coordination of motor bursts to afferent input corresponds to that of active, rhythmic movements in vivo. 2. Entrainment was rapid in onset (stable coordination resulting within the first or second stimulus cycle) and was relatively phase-constant (whatever the stimulus frequency, during 1:1 entrainment, remotor bursts began near the onset of stretch and promotor bursts began near the onset of release). Outside the range of 1:1 entrainment, 2:1, 1:2, and 1:3 coordination ratios (rhythm:stimulus) were encountered. Resetting by phasic stimulation of the TCMRO was complete and probabilistic: effective stimuli triggered rapid transitions between the two burst phases. 3. The TCMRO is innervated by two afferents, the nonspiking S and T fibers, which generate graded depolarizing receptor potentials in response to stretch. During proprioceptive entrainment, the more phasic T fiber depolarized and hyperpolarized more rapidly or in advance of the more tonic S fiber. These receptor potentials were modified differently in the two afferents by interaction with central synaptic inputs that were phase-locked to the entrained motor rhythm. 4. Injecting slow sinusoidal current into either afferent alone could entrain motor rhythms: promoter phase bursts were entrained to depolarization of the S fiber or hyperpolarization of the T fiber, whereas the converse response was obtained for remotor phase bursts. 5. During proprioceptive entrainment, tonic hyperpolarization of the S fiber weakened entrained promotor bursts and allowed remotor burst durations to increase

  3. The Visual System

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  4. A dynamical systems analysis of afferent control in a neuromechanical model of locomotion: II. Phase asymmetry.

    Science.gov (United States)

    Spardy, Lucy E; Markin, Sergey N; Shevtsova, Natalia A; Prilutsky, Boris I; Rybak, Ilya A; Rubin, Jonathan E

    2011-12-01

    In this paper we analyze a closed loop neuromechanical model of locomotor rhythm generation. The model is composed of a spinal central pattern generator (CPG) and a single-joint limb, with CPG outputs projecting via motoneurons to muscles that control the limb and afferent signals from the muscles feeding back to the CPG. In a preceding companion paper (Spardy et al 2011 J. Neural Eng. 8 065003), we analyzed how the model generates oscillations in the presence or absence of feedback, identified curves in a phase plane associated with the limb that signify where feedback levels induce phase transitions within the CPG, and explained how increasing feedback strength restores oscillations in a model representation of spinal cord injury; from these steps, we derived insights about features of locomotor rhythms in several scenarios and made predictions about rhythm responses to various perturbations. In this paper, we exploit our analytical observations to construct a reduced model that retains important characteristics from the original system. We prove the existence of an oscillatory solution to the reduced model using a novel version of a Melnikov function, adapted for discontinuous systems, and also comment on the uniqueness and stability of this solution. Our analysis yields a deeper understanding of how the model must be tuned to generate oscillations and how the details of the limb dynamics shape overall model behavior. In particular, we explain how, due to the feedback signals in the model, changes in the strength of a tonic supra-spinal drive to the CPG yield asymmetric alterations in the durations of different locomotor phases, despite symmetry within the CPG itself.

  5. Visual computing scientific visualization and imaging systems

    CERN Document Server

    2014-01-01

    This volume aims to stimulate discussions on research involving the use of data and digital images as an understanding approach for analysis and visualization of phenomena and experiments. The emphasis is put not only on graphically representing data as a way of increasing its visual analysis, but also on the imaging systems which contribute greatly to the comprehension of real cases. Scientific Visualization and Imaging Systems encompass multidisciplinary areas, with applications in many knowledge fields such as Engineering, Medicine, Material Science, Physics, Geology, Geographic Information Systems, among others. This book is a selection of 13 revised and extended research papers presented in the International Conference on Advanced Computational Engineering and Experimenting -ACE-X conferences 2010 (Paris), 2011 (Algarve), 2012 (Istanbul) and 2013 (Madrid). The examples were particularly chosen from materials research, medical applications, general concepts applied in simulations and image analysis and ot...

  6. The Visual System

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    Full Text Available ... programs with respect to blinding eye diseases, visual disorders, mechanisms of visual function, preservation of sight, and the special health problems and ... Health Information Frequently asked questions ...

  7. Cortical afferents of visual area MT in the Cebus monkey: possible homologies between New and Old World monkeys.

    Science.gov (United States)

    Rosa, M G; Soares, J G; Fiorani, M; Gattass, R

    1993-01-01

    Cortical projections to the middle temporal (MT) visual area were studied by injecting the retrogradely transported fluorescent tracer Fast Blue into MT in adult New World monkeys (Cebus apella). Injection sites were selected based on electrophysiological recordings, and covered eccentricities from 2-70 deg, in both the upper and lower visual fields. The position and laminar distribution of labeled cell bodies were correlated with myeloarchitectonic boundaries and displayed in flat reconstructions of the neocortex. Topographically organized projections were found to arise mainly from the primary, second, third, and fourth visual areas (V1, V2, V3, and V4). Coarsely topographic patterns were observed in transitional V4 (V4t), in the parieto-occipital and parieto-occipital medial areas (PO and POm), and in the temporal ventral posterior area (TVP). In addition, widespread or nontopographic label was found in visual areas of the superior temporal sulcus (medial superior temporal, MST, and fundus of superior temporal, FST), annectent gyrus (dorsointermediate area, DI; and dorsomedial area, DM), intraparietal sulcus (lateral intraparietal, LIP; posterior intraparietal, PIP; and ventral intraparietal, VIP), and in the frontal eye field (FEF). Label in PO, POm, and PIP was found only after injections in the representation of the peripheral visual field (> 10 deg), and label in V4 and FST was more extensive after injections in the central representation. The projections from V1 and V2 originated predominantly from neurons in supragranular layers, whereas those from V3, V4t, DM, DI, POm, and FEF consisted of intermixed patches with either supragranular or infragranular predominance. All of the other projections were predominantly infragranular. Invasion of area MST by the injection site led to the labeling of further pathways, including substantial projections from the dorsal prelunate area (DP) and from an ensemble of areas located along the medial wall of the hemisphere

  8. Complex Digital Visual Systems

    Science.gov (United States)

    Sweeny, Robert W.

    2013-01-01

    This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…

  9. Complex Digital Visual Systems

    Science.gov (United States)

    Sweeny, Robert W.

    2013-01-01

    This article identifies possibilities for data visualization as art educational research practice. The author presents an analysis of the relationship between works of art and digital visual culture, employing aspects of network analysis drawn from the work of Barabási, Newman, and Watts (2006) and Castells (1994). Describing complex network…

  10. The Visual System

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    Full Text Available ... of visual function, preservation of sight, and the special health problems and requirements of the blind.” News & ... Emily Y. Chew, M.D., Deputy Clinical Director Education Programs National Eye Health Education Program (NEHEP) Diabetic ...

  11. Multiple system atrophy (MSA) with massive macrophage infiltration in the ponto-cerebellar afferent system.

    Science.gov (United States)

    Yokoyama, Teruo; Hasegawa, Kazuko; Horiuchi, Emiko; Yagishita, Saburou

    2007-08-01

    Multiple system atrophy (MSA) is characterized pathologically by a systemic degeneration of the olivopontocerebellar (OPC), striatonigral (SN) and autonomic systems. Massive glial cytoplasmic inclusions (GCIs) are specific for this disease. Massive lipid-laden macrophage infiltration in the degenerating tracts has not been described up to now. We here report a case of MSA with this rare event in the ponto-cerebellar (cerebellopetal) fibers. The patient, 54-year-old housewife, developed ataxia. At the age of 55 years, she was diagnosed as having MSA by cerebellar ataxia, extrapyramidal signs, autonomic failure and Horner syndrome. She died from asphyxia at the age of 57. The autopsy revealed OPC and SN system atrophy, degeneration and numerous GCIs, compatible with MSA. Numerous lipid-laden macrophages were seen in the pontine nuclei and its transverse fibers including the white matter of the cerebellum, which has not been reported up to now. There was no macrophage infiltration in the other areas. Transient ischemia, infarction and wallerian degeneration do not account for this rare event. The ponto-cerebellar (cerebellopetal) tract pathology, as observed by postmortem neuropathological study, may occur in the context of MSA.

  12. Neurophysiological changes in the afferent somatosensory system indices in the case of vertebrogenic spine pathology in miners

    Directory of Open Access Journals (Sweden)

    Sharbanu Battakova

    2013-04-01

    Full Text Available Objectives: The aim of the paper was to prove that job conditions impact the state of the afferent part of the somatosensory system in miners. Materials and Methods: Data analysis of the electrophysiological examination of the syndrome in 148 patients, aged from 28 to 55 years, with a mild, moderate and severe degree of the pain syndrome was performed. The control group included 28 people without any pain symptoms. The method used was that of somatosensory stimulated potential (SSP with the potentials amplitude and latency main components taken into consideration. Results: It was proven that the true decrease of the somatosensory stimulated potential SSP N22 (p < 0.05 component amplitudes by 41%; N30 component amplitude tend to decrease by 26%. This proves that the true N22 (p < 0.01 component latency increase by 63.8% corresponds to afferent excitation wave conductibility under the pain syndrome of vertebral pathology through sensitivity pathways mainly in the posterior spinal cord columns and then, through the parts of the brain stem, involving the cerebral cortex, which is confirmed by the fact that the P38 and P46 components amplitudes tend to decrease. In addition to this, the proven N10–N13 (p < 0.05, N13–N20 (p < 0.05, N10–N20 (p < 0.05 intervals increases by 43.5–41.8–38.7%, respectively, correspond to the nervous impulse conductibility through the peripheral nervous system structures and allow to reveal the subclinical slowdown of impulse conductibility, which indicates that the conducting system is changed even under a mild pain syndrome. Conclusions: It was found that the data obtained allow for the better understanding of how the neuropathological pain syndrome under vertebral spine pathology is formed.

  13. The Visual System

    Medline Plus

    Full Text Available ... visual function, preservation of sight, and the special health problems and requirements of the blind.” News & Events Events Calendar NEI Press Releases News from NEI Grantees Spokesperson bios Statistics and ... Frequently asked questions Clinical Studies Publications Catalog ...

  14. Science information systems: Visualization

    Science.gov (United States)

    Wall, Ray J.

    1991-01-01

    Future programs in earth science, planetary science, and astrophysics will involve complex instruments that produce data at unprecedented rates and volumes. Current methods for data display, exploration, and discovery are inadequate. Visualization technology offers a means for the user to comprehend, explore, and examine complex data sets. The goal of this program is to increase the effectiveness and efficiency of scientists in extracting scientific information from large volumes of instrument data.

  15. Corporate Visual Identity Systems origin

    OpenAIRE

    Raposo, D.

    2009-01-01

    Este artigo trata de fazer um pequeno recorrido histórico sobre como a marca se converteu nos sistemas de identidade visual corporativa. Alguns dos principais projectos de identidade ajudam a entender quais as motivações que originaram a necessidade de organização dos sistemas de identidade. Abstract: This paper is a short path about how brands became Corporate Visual Identity Systems. Some of the biggest and emblematic corporate identity projects are helpful to understand which moti...

  16. Modulation of cochlear afferent response by the lateral olivocochlear system: activation via electrical stimulation of the inferior colliculus.

    Science.gov (United States)

    Groff, J Alan; Liberman, M Charles

    2003-11-01

    The olivocochlear (OC) efferent innervation of the mammalian inner ear consists of two subdivisions, medial (MOC) and lateral (LOC), with different peripheral terminations on outer hair cells and cochlear afferent terminals, respectively. The cochlear effects of electrically activating MOC efferents are well known, i.e., response suppression effected by reducing outer hair cells' contribution to cochlear amplification. LOC peripheral effects are unknown, because their unmyelinated axons are difficult to electrically stimulate. Here, stimulating electrodes are placed in the inferior colliculus (IC) to indirectly activate the LOC system, while recording cochlear responses bilaterally from anesthetized guinea pigs. Shocks at some IC sites produced novel cochlear effects attributable to activation of the LOC system: long-lasting (5-20 min) enhancement or suppression of cochlear neural responses (compound action potentials and round window noise), without changes in cochlear responses dominated by outer hair cells (otoacoustic emissions and cochlear microphonics). These novel effects also differed from classic MOC effects in their lack of dependence on the level and frequency of the acoustic stimulus. These effects disappeared on sectioning the entire OC bundle, but not after selective lesioning of the MOC tracts or the cochlea's autonomic innervation. We conclude that the LOC pathway comprises two functional subdivisions, capable of inducing slow increases or decreases in response magnitudes in the auditory nerve. Such a system may be useful in maintaining accurate binaural comparisons necessary for sound localization in the face of slow changes in interaural sensitivity.

  17. Cerebellar and afferent ataxias.

    Science.gov (United States)

    Pandolfo, Massimo; Manto, Mario

    2013-10-01

    Ataxia is the predominant manifestation of many acquired and inherited neurologic disorders affecting the cerebellum, its connections, and the afferent proprioceptive pathways. This article reviews the phenomenology and etiologies of cerebellar and afferent ataxias and provides indications for a rational approach to diagnosis and management. The pathophysiology of ataxia is being progressively understood and linked to the functional organization of the cerebellum. The impact of cerebellar diseases on different neurologic functions has been better defined and shown not to be limited to loss of motor coordination. The role of autoimmunity is increasingly recognized as a cause of sporadic cases of ataxia. Large collaborative studies of long duration are providing crucial information on the clinical spectrum and natural history of both sporadic ataxias (such as the cerebellar form of multiple system atrophy) and inherited ataxias. New dominant and recessive ataxia genes have been identified. On the therapeutic front, progress mostly concerns the development of treatments for Friedreich ataxia. Ataxia is the clinical manifestation of a wide range of disorders. In addition to accurate clinical assessment, MRI plays a major role in the diagnostic workup, allowing us to distinguish degenerative conditions from those due to other types of structural damage to the cerebellar or proprioceptive systems. Diagnostic algorithms based on clinical features, imaging, and neurophysiologic and biochemical parameters can be used to guide genetic testing for hereditary ataxias, the diagnosis of which is likely to be greatly improved by the introduction of new-generation DNA-sequencing approaches. Some rare forms of ataxia can be treated, so their diagnosis should not be missed. Proven symptomatic treatments for ataxia are still lacking, but intensive physical therapy appears to be helpful.

  18. Relating Standardized Visual Perception Measures to Simulator Visual System Performance

    Science.gov (United States)

    Kaiser, Mary K.; Sweet, Barbara T.

    2013-01-01

    Human vision is quantified through the use of standardized clinical vision measurements. These measurements typically include visual acuity (near and far), contrast sensitivity, color vision, stereopsis (a.k.a. stereo acuity), and visual field periphery. Simulator visual system performance is specified in terms such as brightness, contrast, color depth, color gamut, gamma, resolution, and field-of-view. How do these simulator performance characteristics relate to the perceptual experience of the pilot in the simulator? In this paper, visual acuity and contrast sensitivity will be related to simulator visual system resolution, contrast, and dynamic range; similarly, color vision will be related to color depth/color gamut. Finally, we will consider how some characteristics of human vision not typically included in current clinical assessments could be used to better inform simulator requirements (e.g., relating dynamic characteristics of human vision to update rate and other temporal display characteristics).

  19. Unmyelinated visceral afferents exhibit frequency dependent action potential broadening while myelinated visceral afferents do not.

    Science.gov (United States)

    Li, Bai-Yan; Feng, Bin; Tsu, Hwa Y; Schild, John H

    2007-06-21

    Sensory information arising from visceral organ systems is encoded into action potential trains that propagate along afferent fibers to target nuclei in the central nervous system. These information streams range from tight patterns of action potentials that are well synchronized with the sensory transduction event to irregular, patternless discharge with no clear correlation to the sensory input. In general terms these afferent pathways can be divided into unmyelinated and myelinated fiber types. Our laboratory has a long standing interest in the functional differences between these two types of afferents in terms of the preprocessing of sensory information into action potential trains (synchrony, frequency, duration, etc.), the reflexogenic consequences of this sensory input to the central nervous system and the ionic channels that give rise to the electrophysiological properties of these unique cell types. The aim of this study was to determine whether there were any functional differences in the somatic action potential characteristics of unmyelinated and myelinated vagal afferents in response to different rates of sensory nerve stimulation. Our results showed that activity and frequency-dependent widening of the somatic action potential was quite prominent in unmyelinated but not myelinated vagal afferents. Spike broadening often leads to increased influx of Ca(2+) ions that has been associated with a diverse range of modulatory mechanisms both at the cell body and central synaptic terminations (e.g. increased neurotransmitter release.) We conclude that our observations are indicative of fundamentally different mechanisms for neural integration of sensory information arising from unmyelinated and myelinated vagal afferents.

  20. Microstructural visual system changes in AQP4-antibody-seropositive NMOSD.

    Science.gov (United States)

    Oertel, Frederike C; Kuchling, Joseph; Zimmermann, Hanna; Chien, Claudia; Schmidt, Felix; Knier, Benjamin; Bellmann-Strobl, Judith; Korn, Thomas; Scheel, Michael; Klistorner, Alexander; Ruprecht, Klemens; Paul, Friedemann; Brandt, Alexander U

    2017-05-01

    To trace microstructural changes in patients with aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorders (NMOSDs) by investigating the afferent visual system in patients without clinically overt visual symptoms or visual pathway lesions. Of 51 screened patients with NMOSD from a longitudinal observational cohort study, we compared 6 AQP4-ab-seropositive NMOSD patients with longitudinally extensive transverse myelitis (LETM) but no history of optic neuritis (ON) or other bout (NMOSD-LETM) to 19 AQP4-ab-seropositive NMOSD patients with previous ON (NMOSD-ON) and 26 healthy controls (HCs). Foveal thickness (FT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and ganglion cell and inner plexiform layer (GCIPL) thickness were measured with optical coherence tomography (OCT). Microstructural changes in the optic radiation (OR) were investigated using diffusion tensor imaging (DTI). Visual function was determined by high-contrast visual acuity (VA). OCT results were confirmed in a second independent cohort. FT was reduced in both patients with NMOSD-LETM (p = 3.52e(-14)) and NMOSD-ON (p = 1.24e(-16)) in comparison with HC. Probabilistic tractography showed fractional anisotropy reduction in the OR in patients with NMOSD-LETM (p = 0.046) and NMOSD-ON (p = 1.50e(-5)) compared with HC. Only patients with NMOSD-ON but not NMOSD-LETM showed neuroaxonal damage in the form of pRNFL and GCIPL thinning. VA was normal in patients with NMOSD-LETM and was not associated with OCT or DTI parameters. Patients with AQP4-ab-seropositive NMOSD without a history of ON have microstructural changes in the afferent visual system. The localization of retinal changes around the Müller-cell rich fovea supports a retinal astrocytopathy.

  1. Microstructural visual system changes in AQP4-antibody–seropositive NMOSD

    Science.gov (United States)

    Oertel, Frederike C.; Kuchling, Joseph; Zimmermann, Hanna; Chien, Claudia; Schmidt, Felix; Knier, Benjamin; Bellmann-Strobl, Judith; Korn, Thomas; Scheel, Michael; Klistorner, Alexander; Ruprecht, Klemens; Paul, Friedemann

    2017-01-01

    Objective: To trace microstructural changes in patients with aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorders (NMOSDs) by investigating the afferent visual system in patients without clinically overt visual symptoms or visual pathway lesions. Methods: Of 51 screened patients with NMOSD from a longitudinal observational cohort study, we compared 6 AQP4-ab–seropositive NMOSD patients with longitudinally extensive transverse myelitis (LETM) but no history of optic neuritis (ON) or other bout (NMOSD-LETM) to 19 AQP4-ab–seropositive NMOSD patients with previous ON (NMOSD-ON) and 26 healthy controls (HCs). Foveal thickness (FT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and ganglion cell and inner plexiform layer (GCIPL) thickness were measured with optical coherence tomography (OCT). Microstructural changes in the optic radiation (OR) were investigated using diffusion tensor imaging (DTI). Visual function was determined by high-contrast visual acuity (VA). OCT results were confirmed in a second independent cohort. Results: FT was reduced in both patients with NMOSD-LETM (p = 3.52e−14) and NMOSD-ON (p = 1.24e−16) in comparison with HC. Probabilistic tractography showed fractional anisotropy reduction in the OR in patients with NMOSD-LETM (p = 0.046) and NMOSD-ON (p = 1.50e−5) compared with HC. Only patients with NMOSD-ON but not NMOSD-LETM showed neuroaxonal damage in the form of pRNFL and GCIPL thinning. VA was normal in patients with NMOSD-LETM and was not associated with OCT or DTI parameters. Conclusions: Patients with AQP4-ab–seropositive NMOSD without a history of ON have microstructural changes in the afferent visual system. The localization of retinal changes around the Müller-cell rich fovea supports a retinal astrocytopathy. PMID:28255575

  2. Visual system manifestations of Alzheimer's disease.

    Science.gov (United States)

    Kusne, Yael; Wolf, Andrew B; Townley, Kate; Conway, Mandi; Peyman, Gholam A

    2016-11-19

    Alzheimer's disease (AD) is an increasingly common disease with massive personal and economic costs. While it has long been known that AD impacts the visual system, there has recently been an increased focus on understanding both pathophysiological mechanisms that may be shared between the eye and brain and how related biomarkers could be useful for AD diagnosis. Here, were review pertinent cellular and molecular mechanisms of AD pathophysiology, the presence of AD pathology in the visual system, associated functional changes, and potential development of diagnostic tools based on the visual system. Additionally, we discuss links between AD and visual disorders, including possible pathophysiological mechanisms and their relevance for improving our understanding of AD.

  3. Electromagnetic System Design and Visual Simulation

    Institute of Scientific and Technical Information of China (English)

    ZHANGJing-shu; CHENDe-gui; NIUChun-ping

    2004-01-01

    An electromagnet design system is developed using Visual C++ language and OpenGL technology to visualize parametric 3D model. The system consists of primary design,optimization design, dynamic and static characteristics, and visual simulation. All empirical parameters and curves used in design process are stored in database. Through human-computer interactions, an electromagnetic system can be designed conveniently with the results and characteristics curves displayed in graphic model. Using this system can greatly shorten the process of product design, and the results satisfy technical requirements.

  4. Birth order dependent growth cone segregation determines synaptic layer identity in the Drosophila visual system.

    Science.gov (United States)

    Kulkarni, Abhishek; Ertekin, Deniz; Lee, Chi-Hon; Hummel, Thomas

    2016-03-17

    The precise recognition of appropriate synaptic partner neurons is a critical step during neural circuit assembly. However, little is known about the developmental context in which recognition specificity is important to establish synaptic contacts. We show that in the Drosophila visual system, sequential segregation of photoreceptor afferents, reflecting their birth order, lead to differential positioning of their growth cones in the early target region. By combining loss- and gain-of-function analyses we demonstrate that relative differences in the expression of the transcription factor Sequoia regulate R cell growth cone segregation. This initial growth cone positioning is consolidated via cell-adhesion molecule Capricious in R8 axons. Further, we show that the initial growth cone positioning determines synaptic layer selection through proximity-based axon-target interactions. Taken together, we demonstrate that birth order dependent pre-patterning of afferent growth cones is an essential pre-requisite for the identification of synaptic partner neurons during visual map formation in Drosophila.

  5. Using Visualization in Cockpit Decision Support Systems

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.

    2005-07-01

    In order to safely operate their aircraft, pilots must makerapid decisions based on integrating and processing large amounts ofheterogeneous information. Visual displays are often the most efficientmethod of presenting safety-critical data to pilots in real time.However, care must be taken to ensure the pilot is provided with theappropriate amount of information to make effective decisions and notbecome cognitively overloaded. The results of two usability studies of aprototype airflow hazard visualization cockpit decision support systemare summarized. The studies demonstrate that such a system significantlyimproves the performance of helicopter pilots landing under turbulentconditions. Based on these results, design principles and implicationsfor cockpit decision support systems using visualization arepresented.

  6. Sensations evoked by microstimulation of single mechanoreceptive afferents innervating the human face and mouth.

    Science.gov (United States)

    Trulsson, M; Essick, G K

    2010-04-01

    Intraneural microneurography and microstimulation were performed on single afferent axons in the inferior alveolar and lingual nerves innervating the face, teeth, labial, or oral mucosa. Using natural mechanical stimuli, 35 single mechanoreceptive afferents were characterized with respect to unit type [fast adapting type I (FA I), FA hair, slowly adapting type I and II (SA I and SA II), periodontal, and deep tongue units] as well as size and shape of the receptive field. All afferents were subsequently microstimulated with pulse trains at 30 Hz lasting 1.0 s. Afferents recordings whose were stable thereafter were also tested with single pulses and pulse trains at 5 and 60 Hz. The results revealed that electrical stimulation of single FA I, FA hair, and SA I afferents from the orofacial region can evoke a percept that is spatially matched to the afferent's receptive field and consistent with the afferent's response properties as observed on natural mechanical stimulation. Stimulation of FA afferents typically evoked sensations that were vibratory in nature; whereas those of SA I afferents were felt as constant pressure. These afferents terminate superficially in the orofacial tissues and seem to have a particularly powerful access to perceptual levels. In contrast, microstimulation of single periodontal, SA II, and deep tongue afferents failed to evoke a sensation that matched the receptive field of the afferent. These afferents terminate more deeply in the tissues, are often active in the absence of external stimulation, and probably access perceptual levels only when multiple afferents are stimulated. It is suggested that the spontaneously active afferents that monitor tension in collagen fibers (SA II and periodontal afferents) may have the role to register the mechanical state of the soft tissues, which has been hypothesized to help maintain the body's representation in the central somatosensory system.

  7. Visual computing model for immune system and medical system.

    Science.gov (United States)

    Gong, Tao; Cao, Xinxue; Xiong, Qin

    2015-01-01

    Natural immune system is an intelligent self-organizing and adaptive system, which has a variety of immune cells with different types of immune mechanisms. The mutual cooperation between the immune cells shows the intelligence of this immune system, and modeling this immune system has an important significance in medical science and engineering. In order to build a comprehensible model of this immune system for better understanding with the visualization method than the traditional mathematic model, a visual computing model of this immune system was proposed and also used to design a medical system with the immune system, in this paper. Some visual simulations of the immune system were made to test the visual effect. The experimental results of the simulations show that the visual modeling approach can provide a more effective way for analyzing this immune system than only the traditional mathematic equations.

  8. Visualizing Mobility of Public Transportation System.

    Science.gov (United States)

    Zeng, Wei; Fu, Chi-Wing; Arisona, Stefan Müller; Erath, Alexander; Qu, Huamin

    2014-12-01

    Public transportation systems (PTSs) play an important role in modern cities, providing shared/massive transportation services that are essential for the general public. However, due to their increasing complexity, designing effective methods to visualize and explore PTS is highly challenging. Most existing techniques employ network visualization methods and focus on showing the network topology across stops while ignoring various mobility-related factors such as riding time, transfer time, waiting time, and round-the-clock patterns. This work aims to visualize and explore passenger mobility in a PTS with a family of analytical tasks based on inputs from transportation researchers. After exploring different design alternatives, we come up with an integrated solution with three visualization modules: isochrone map view for geographical information, isotime flow map view for effective temporal information comparison and manipulation, and OD-pair journey view for detailed visual analysis of mobility factors along routes between specific origin-destination pairs. The isotime flow map linearizes a flow map into a parallel isoline representation, maximizing the visualization of mobility information along the horizontal time axis while presenting clear and smooth pathways from origin to destinations. Moreover, we devise several interactive visual query methods for users to easily explore the dynamics of PTS mobility over space and time. Lastly, we also construct a PTS mobility model from millions of real passenger trajectories, and evaluate our visualization techniques with assorted case studies with the transportation researchers.

  9. Earth orbital teleoperator visual system evaluation program

    Science.gov (United States)

    Shields, N. L., Jr.; Kirkpatrick, M., III; Frederick, P. N.; Malone, T. B.

    1975-01-01

    Empirical tests of range estimation accuracy and resolution, via television, under monoptic and steroptic viewing conditions are discussed. Test data are used to derive man machine interface requirements and make design decisions for an orbital remote manipulator system. Remote manipulator system visual tasks are given and the effects of system parameters of these tasks are evaluated.

  10. Visual system plasticity in mammals: the story of monocular enucleation-induced vision loss.

    Science.gov (United States)

    Nys, Julie; Scheyltjens, Isabelle; Arckens, Lutgarde

    2015-01-01

    The groundbreaking work of Hubel and Wiesel in the 1960's on ocular dominance plasticity instigated many studies of the visual system of mammals, enriching our understanding of how the development of its structure and function depends on high quality visual input through both eyes. These studies have mainly employed lid suturing, dark rearing and eye patching applied to different species to reduce or impair visual input, and have created extensive knowledge on binocular vision. However, not all aspects and types of plasticity in the visual cortex have been covered in full detail. In that regard, a more drastic deprivation method like enucleation, leading to complete vision loss appears useful as it has more widespread effects on the afferent visual pathway and even on non-visual brain regions. One-eyed vision due to monocular enucleation (ME) profoundly affects the contralateral retinorecipient subcortical and cortical structures thereby creating a powerful means to investigate cortical plasticity phenomena in which binocular competition has no vote.In this review, we will present current knowledge about the specific application of ME as an experimental tool to study visual and cross-modal brain plasticity and compare early postnatal stages up into adulthood. The structural and physiological consequences of this type of extensive sensory loss as documented and studied in several animal species and human patients will be discussed. We will summarize how ME studies have been instrumental to our current understanding of the differentiation of sensory systems and how the structure and function of cortical circuits in mammals are shaped in response to such an extensive alteration in experience. In conclusion, we will highlight future perspectives and the clinical relevance of adding ME to the list of more longstanding deprivation models in visual system research.

  11. [Review of visual display system in flight simulator].

    Science.gov (United States)

    Xie, Guang-hui; Wei, Shao-ning

    2003-06-01

    Visual display system is the key part and plays a very important role in flight simulators and flight training devices. The developing history of visual display system is recalled and the principle and characters of some visual display systems including collimated display systems and back-projected collimated display systems are described. The future directions of visual display systems are analyzed.

  12. Sex differences in the human visual system.

    Science.gov (United States)

    Vanston, John E; Strother, Lars

    2017-01-02

    This Mini-Review summarizes a wide range of sex differences in the human visual system, with a primary focus on sex differences in visual perception and its neural basis. We highlight sex differences in both basic and high-level visual processing, with evidence from behavioral, neurophysiological, and neuroimaging studies. We argue that sex differences in human visual processing, no matter how small or subtle, support the view that females and males truly see the world differently. We acknowledge some of the controversy regarding sex differences in human vision and propose that such controversy should be interpreted as a source of motivation for continued efforts to assess the validity and reliability of published sex differences and for continued research on sex differences in human vision and the nervous system in general. © 2016 Wiley Periodicals, Inc.

  13. Reading into neuronal oscillations in the visual system: implications for developmental dyslexia

    Directory of Open Access Journals (Sweden)

    Trichur Raman Vidyasagar

    2013-11-01

    Full Text Available While phonological impairments are common in developmental dyslexia, there has recently been much debate as to whether there is a causal link between the phonological difficulties and the reading problem. An alternative suggestion has been gaining ground that the core deficit in dyslexia is in visual attentional mechanisms. If so, the visual aetiology may be at any of a number of sites along the afferent magnocellular pathway or in the dorsal cortical stream that are all essential for a visuo-spatial attentional feedback to the primary visual cortex. It has been suggested that the same circuits and pathways of top-down attention used for serial visual search are used for reading. Top-down signals from the dorsal parietal areas to primary visual cortex serially highlight cortical locations representing successive letters in a text before they can be recognised and concatenated into a word. We had shown in non-human primates that the mechanism of such a top-down feedback in a visual attention task uses synchronized neuronal oscillations at the lower end of the gamma frequency range. It is no coincidence that reading graphemes in a text also happens at the low gamma frequencies. The basic proposal here is that each cycle of gamma oscillation focuses an attentional spotlight on the primary visual cortical representation of just one or two letters before sequential recognition of letters and their concatenation into word strings. The timing, period, envelope, amplitude and phase of the synchronized oscillations modulating the incoming signals in the striate cortex would have a profound influence on the accuracy and speed of reading. Thus the general temporal sampling difficulties in dyslexic subjects may impact reading not necessarily by causing phonological deficits, but by affecting the spatio-temporal parsing of the visual input within the visual system before these signals are used for letter and word recognition.

  14. Reading into neuronal oscillations in the visual system: implications for developmental dyslexia.

    Science.gov (United States)

    Vidyasagar, Trichur R

    2013-01-01

    While phonological impairments are common in developmental dyslexia, there has recently been much debate as to whether there is a causal link between the phonological difficulties and the reading problem. An alternative suggestion has been gaining ground that the core deficit in dyslexia is in visual attentional mechanisms. If so, the visual aetiology may be at any of a number of sites along the afferent magnocellular pathway or in the dorsal cortical stream that are all essential for a visuo-spatial attentional feedback to the primary visual cortex. It has been suggested that the same circuits and pathways of top-down attention used for serial visual search are used for reading. Top-down signals from the dorsal parietal areas to primary visual cortex serially highlight cortical locations representing successive letters in a text before they can be recognized and concatenated into a word. We had shown in non-human primates that the mechanism of such a top-down feedback in a visual attention task uses synchronized neuronal oscillations at the lower end of the gamma frequency range. It is no coincidence that reading graphemes in a text also happens at the low gamma frequencies. The basic proposal here is that each cycle of gamma oscillation focuses an attentional spotlight on the primary visual cortical representation of just one or two letters before sequential recognition of letters and their concatenation into word strings. The timing, period, envelope, amplitude, and phase of the synchronized oscillations modulating the incoming signals in the striate cortex would have a profound influence on the accuracy and speed of reading. Thus, the general temporal sampling difficulties in dyslexic subjects may impact reading not necessarily by causing phonological deficits, but by affecting the spatio-temporal parsing of the visual input within the visual system before these signals are used for letter and word recognition.

  15. Visual Tracking System for Welding Seams

    Institute of Scientific and Technical Information of China (English)

    Zeng-shun ZHAO; Ji-zhen WANG; Xue-Zhen CHENG

    2010-01-01

    To track the narrow butt welding seams in container manufacture, a visual tracking system based on smart camera is proposed in this paper. A smart camera is used as the sensor to detect the welding seam. The feature extraction algorithm is designed with the consideration of the characteristics of the smart camera, which is used to compute the error between the welding torch and the welding seam. Visual control system based on image is presented, which employs a programmable controller to control a stepper motor to eliminate the tracking error detected by the smart camera. Experiments are conducted to demonstrate the effectiveness of the vision system.

  16. Visual systems - The state of the art

    Science.gov (United States)

    Shorrock, David

    State-of-the-art, computer-generated image simulator visual systems typically encompass a data base which generates the model of the operating environment, an image generator, and a display system suitable for the applications envisaged. Two basic approaches to such systems are discernible: those employing hybrid raster/calligraphy and those using raster/continuous tone. Attention is presently given to such capabilities and elements of visual displays as texture effects, transparencies, fade level-of-detail management, animation effects, and image generator functions for daylight and night/dusk conditions, as well as prospective developments in this field.

  17. Scientific & Intelligence Exascale Visualization Analysis System

    Energy Technology Data Exchange (ETDEWEB)

    2017-07-14

    SIEVAS provides an immersive visualization framework for connecting multiple systems in real time for data science. SIEVAS provides the ability to connect multiple COTS and GOTS products in a seamless fashion for data fusion, data analysis, and viewing. It provides this capability by using a combination of micro services, real time messaging, and web service compliant back-end system.

  18. Development of the cerebellar afferent system in the shark Scyliorhinus canicula: insights into the basal organization of precerebellar nuclei in gnathostomes.

    Science.gov (United States)

    Pose-Méndez, Sol; Candal, Eva; Adrio, Fátima; Rodríguez-Moldes, Isabel

    2014-01-01

    The cerebellum is recognized as an evolutionary innovation of jawed vertebrates, whose most primitive group is represented by the chondrichthyans, or cartilaginous fishes. A comprehensive knowledge of cerebellar connections in these fishes might shed light on the basal organization of the cerebellar system. Although the organization of the precerebellar system is known in adults, developmental studies are essential for understanding the origin and evolution of precerebellar nuclei. In the present work we performed a developmental study of cerebellar connections in embryos and juveniles of an advanced shark species, Scyliorhinus canicula, by application of tract tracing in combination with immunohistochemical techniques. Main precerebellar cell populations were located in the diencephalon (pretectum and thalamus), mesencephalon (reticular formation and nucleus ruber), rhombencephalon (cerebellar nucleus, reticular formation, and inferior olive), and spinal cord (ventral horn). The order of arrival of cerebellar afferent projections throughout development revealed a common pattern with other jawed vertebrates, which was helpful for comparison of stages of cerebellar development. The neurochemical study of the inferior olive and other precerebellar nuclei revealed many shared features with other gnathostomes. Furthermore, because many precerebellar nuclei originate from rhombic lips, the first analysis of neuronal migrations from these lips was performed with markers of neuroblasts. The shared features of development and organization of precerebellar connections observed between sharks and amniotes suggest that their basic pattern was established early in gnathostome evolution. Copyright © 2013 Wiley Periodicals, Inc.

  19. Visualizing complex (hydrological) systems with correlation matrices

    Science.gov (United States)

    Haas, J. C.

    2016-12-01

    When trying to understand or visualize the connections of different aspects of a complex system, this often requires deeper understanding to start with, or - in the case of geo data - complicated GIS software. To our knowledge, correlation matrices have rarely been used in hydrology (e.g. Stoll et al., 2011; van Loon and Laaha, 2015), yet they do provide an interesting option for data visualization and analysis. We present a simple, python based way - using a river catchment as an example - to visualize correlations and similarities in an easy and colorful way. We apply existing and easy to use python packages from various disciplines not necessarily linked to the Earth sciences and can thus quickly show how different aquifers work or react, and identify outliers, enabling this system to also be used for quality control of large datasets. Going beyond earlier work, we add a temporal and spatial element, enabling us to visualize how a system reacts to local phenomena such as for example a river, or changes over time, by visualizing the passing of time in an animated movie. References: van Loon, A.F., Laaha, G.: Hydrological drought severity explained by climate and catchment characteristics, Journal of Hydrology 526, 3-14, 2015, Drought processes, modeling, and mitigation Stoll, S., Hendricks Franssen, H. J., Barthel, R., Kinzelbach, W.: What can we learn from long-term groundwater data to improve climate change impact studies?, Hydrology and Earth System Sciences 15(12), 3861-3875, 2011

  20. Design for a Program Visualization System.

    Science.gov (United States)

    1981-01-01

    level here would run on a DEC VAX- 11/780 computer running of detail that the user may wish to see. At the most the UNIX operating system ( KERNIGHAN ...typographic tools that could be ftry on the UNIX Operating System [LIONS] is a clas- applied to the publishing of programs are: sic example of the value of well...produced by a visualizer run-time executive process. The visual- izer is used in place of the standard UNIX command 1. interact with the user to

  1. Visceral perception: sensory transduction in visceral afferents and nutrients.

    Science.gov (United States)

    Raybould, H E

    2002-07-01

    The possible mechanisms that may be involved in nutrient detection in the wall of the gastrointestinal tract are reviewed. There is strong functional and electrophysiological evidence that both intrinsic and extrinsic primary afferent neurones mediate mechano- and chemosensitive responses in the gastrointestinal tract. This review focuses on the extrinsic afferent pathways as these are the ones that convey information to the central nervous system which is clearly necessary for perception to occur.

  2. Visual-tracking-based robot vision system

    Science.gov (United States)

    Deng, Keqiang; Wilson, Joseph N.; Ritter, Gerhard X.

    1992-11-01

    There are two kinds of depth perception for robot vision systems: quantitative and qualitative. The first one can be used to reconstruct the visible surfaces numerically while the second to describe the visible surfaces qualitatively. In this paper, we present a qualitative vision system suitable for intelligent robots. The goal of such a system is to perceive depth information qualitatively using monocular 2-D images. We first establish a set of propositions relating depth information, such as 3-D orientation and distance, to the changes of image region caused by camera motion. We then introduce an approximation-based visual tracking system. Given an object, the tracking system tracks its image while moving the camera in a way dependent upon the particular depth property to be perceived. Checking the data generated by the tracking system with our propositions provides us the depth information about the object. The visual tracking system can track image regions in real-time even as implemented on a PC AT clone machine, and mobile robots can naturally provide the inputs to our visual tracking system, therefore, we are able to construct a real-time, cost effective, monocular, qualitative and 3-dimensional robot vision system. To verify our idea, we present examples of perception of planar surface orientation, distance, size, dimensionality and convexity/concavity.

  3. Evolutionarily conserved organization of the dopaminergic system in lamprey: SNc/VTA afferent and efferent connectivity and D2 receptor expression.

    Science.gov (United States)

    Pérez-Fernández, Juan; Stephenson-Jones, Marcus; Suryanarayana, Shreyas M; Robertson, Brita; Grillner, Sten

    2014-12-01

    The dopaminergic system influences motor behavior, signals reward and novelty, and is an essential component of the basal ganglia in all vertebrates including the lamprey, one of the phylogenetically oldest vertebrates. The intrinsic organization and function of the lamprey basal ganglia is highly conserved. For instance, the direct and indirect pathways are modulated through dopamine D1 and D2 receptors in lamprey and in mammals. The nucleus of the tuberculum posterior, a homologue of the substantia nigra pars compacta (SNc)/ventral tegmental area (VTA) is present in lamprey, but only scarce data exist about its connectivity. Likewise, the D2 receptor is expressed in the striatum, but little is known about its localization in other brain areas. We used in situ hybridization and tracer injections, both in combination with tyrosine hydroxylase immunohistochemistry, to characterize the SNc/VTA efferent and afferent connectivity, and to relate its projection pattern with D2 receptor expression in particular. We show that most features of the dopaminergic system are highly conserved. As in mammals, the direct pallial (cortex in mammals) input and the basal ganglia connectivity with the SNc/VTA are present as part of the evaluation system, as well as input from the tectum as the evolutionary basis for salience/novelty detection. Moreover, the SNc/VTA receives sensory information from the olfactory bulbs, optic tectum, octavolateral area, and dorsal column nucleus, and it innervates, apart from the nigrostriatal pathway, several motor-related areas. This suggests that the dopaminergic system also contributes to the control of different motor centers at the brainstem level.

  4. Intrusion Detection System Visualization of Network Alerts

    Science.gov (United States)

    2010-07-01

    Intrusion Detection System Visualization of Network Alerts Dolores M. Zage and Wayne M. Zage Ball State University Final Report July 2010...contracts. Staff Wayne Zage, Director of the S2ERC and Professor, Department of Computer Science, Ball State University Dolores Zage, Research

  5. Visual speech gestures modulate efferent auditory system.

    Science.gov (United States)

    Namasivayam, Aravind Kumar; Wong, Wing Yiu Stephanie; Sharma, Dinaay; van Lieshout, Pascal

    2015-03-01

    Visual and auditory systems interact at both cortical and subcortical levels. Studies suggest a highly context-specific cross-modal modulation of the auditory system by the visual system. The present study builds on this work by sampling data from 17 young healthy adults to test whether visual speech stimuli evoke different responses in the auditory efferent system compared to visual non-speech stimuli. The descending cortical influences on medial olivocochlear (MOC) activity were indirectly assessed by examining the effects of contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs) at 1, 2, 3 and 4 kHz under three conditions: (a) in the absence of any contralateral noise (Baseline), (b) contralateral noise + observing facial speech gestures related to productions of vowels /a/ and /u/ and (c) contralateral noise + observing facial non-speech gestures related to smiling and frowning. The results are based on 7 individuals whose data met strict recording criteria and indicated a significant difference in TEOAE suppression between observing speech gestures relative to the non-speech gestures, but only at the 1 kHz frequency. These results suggest that observing a speech gesture compared to a non-speech gesture may trigger a difference in MOC activity, possibly to enhance peripheral neural encoding. If such findings can be reproduced in future research, sensory perception models and theories positing the downstream convergence of unisensory streams of information in the cortex may need to be revised.

  6. "Identifying the hospitalised patient in crisis"--a consensus conference on the afferent limb of rapid response systems

    DEFF Research Database (Denmark)

    DeVita, Michael A; Smith, Gary B; Adam, Sheila K

    2010-01-01

    Most reports of Rapid Response Systems (RRS) focus on the efferent, response component of the system, although evidence suggests that improved vital sign monitoring and recognition of a clinical crisis may have outcome benefits. There is no consensus regarding how best to detect patient deteriora......Most reports of Rapid Response Systems (RRS) focus on the efferent, response component of the system, although evidence suggests that improved vital sign monitoring and recognition of a clinical crisis may have outcome benefits. There is no consensus regarding how best to detect patient...

  7. Visual navigation system for autonomous indoor blimps

    Science.gov (United States)

    Campos, Mario F.; de Souza Coelho, Lucio

    1999-07-01

    Autonomous dirigibles - aerial robots that are a blimp controlled by computer based on information gathered by sensors - are a new and promising research field in Robotics, offering several original work opportunities. One of them is the study of visual navigation of UAVs. In the work described in this paper, a Computer Vision and Control system was developed to perform automatically very simple navigation task for a small indoor blimp. The vision system is able to track artificial visual beacons - objects with known geometrical properties - and from them a geometrical methodology can extract information about orientation of the blimp. The tracking of natural landmarks is also a possibility for the vision technique developed. The control system uses that data to keep the dirigible on a programmed orientation. Experimental results showing the correct and efficient functioning of the system are shown and have your implications and future possibilities discussed.

  8. "Identifying the hospitalised patient in crisis"-A consensus conference on the afferent limb of Rapid Response Systems

    DEFF Research Database (Denmark)

    Devita, M.A.; Smith, G.B.; Adam, S.K.

    2010-01-01

    Background: Most reports of Rapid Response Systems (RRS) focus on the efferent, response component of the system, although evidence suggests that improved vital sign monitoring and recognition of a clinical crisis may have outcome benefits. There is no consensus regarding how best to detect patie...

  9. Lightness computation by the human visual system

    Science.gov (United States)

    Rudd, Michael E.

    2017-05-01

    A model of achromatic color computation by the human visual system is presented, which is shown to account in an exact quantitative way for a large body of appearance matching data collected with simple visual displays. The model equations are closely related to those of the original Retinex model of Land and McCann. However, the present model differs in important ways from Land and McCann's theory in that it invokes additional biological and perceptual mechanisms, including contrast gain control, different inherent neural gains for incremental, and decremental luminance steps, and two types of top-down influence on the perceptual weights applied to local luminance steps in the display: edge classification and spatial integration attentional windowing. Arguments are presented to support the claim that these various visual processes must be instantiated by a particular underlying neural architecture. By pointing to correspondences between the architecture of the model and findings from visual neurophysiology, this paper suggests that edge classification involves a top-down gating of neural edge responses in early visual cortex (cortical areas V1 and/or V2) while spatial integration windowing occurs in cortical area V4 or beyond.

  10. Dependency visualization for complex system understanding

    Energy Technology Data Exchange (ETDEWEB)

    Smart, J. Allison Cory [Univ. of California, Davis, CA (United States)

    1994-09-01

    With the volume of software in production use dramatically increasing, the importance of software maintenance has become strikingly apparent. Techniques now sought and developed for reverse engineering and design extraction and recovery. At present, numerous commercial products and research tools exist which are capable of visualizing a variety of programming languages and software constructs. The list of new tools and services continues to grow rapidly. Although the scope of the existing commercial and academic product set is quite broad, these tools still share a common underlying problem. The ability of each tool to visually organize object representations is increasingly impaired as the number of components and component dependencies within systems increases. Regardless of how objects are defined, complex ``spaghetti`` networks result in nearly all large system cases. While this problem is immediately apparent in modem systems analysis involving large software implementations, it is not new. As will be discussed in Chapter 2, related problems involving the theory of graphs were identified long ago. This important theoretical foundation provides a useful vehicle for representing and analyzing complex system structures. While the utility of directed graph based concepts in software tool design has been demonstrated in literature, these tools still lack the capabilities necessary for large system comprehension. This foundation must therefore be expanded with new organizational and visualization constructs necessary to meet this challenge. This dissertation addresses this need by constructing a conceptual model and a set of methods for interactively exploring, organizing, and understanding the structure of complex software systems.

  11. Analysis of afferent responses from isolated semicircular canal of the guitarfish using rotational acceleration white-noise inputs. II. Estimation of linear system parameters and gain and phase spectra.

    Science.gov (United States)

    O'Leary, D P; Honrubia, V

    1976-05-01

    Quantitative estimates were computed for exponential coefficients and rate constants contributing to afferent unit impulse responses obtained from bundles innervating specific regions of the semicircular canal. The grouping of these estimates into specific response classes provided quantitative correlations with specific anatomical regions of innervation of the crista. Linear system gain and phase spectra were computed also, by applying Fourier transformations to unit impulse responses, for purposes of comparison with previous studies employing frequency domain analyses. Responses fitted by third-order linear system equations were specific to afferents innervating the crest and transition regions of the crista; whereas those fitted by overdamped, second-order equations were specific to afferents innervating the slopes and transition crista regions. It was concluded that strictly mechanical models of the transduction process are inadequate to account for the diverse and spatially distributed classes of observed responses and, moreover, structural features such as different hair cell types or efferent innervation effects could be excluded as inoperative in this preparation. The alternative hypothesis was suggested that certain of the observed subcomponents could be direct reflections of the initial mechanical stimulus, but that other subcomponents were reflections of more complex filtering mechanisms operating at the cellular or synaptic levels.

  12. Visualizing systems engineering data with Java

    Energy Technology Data Exchange (ETDEWEB)

    Barter, Robert H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vinzant, Aleta [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1998-11-10

    Systems Engineers are required to deal with complex sets of data. To be useful, the data must be managed effectively, and presented in meaningful terms to a wide variety of information consumers. Two software patterns are presented as the basis for exploring the visualization of systems engineering data. The Model, View, Controller pattern defines an information management system architecture. The Entity, Relation, Attribute pattern defines the information model. MVC "Views" then form the basis for the user interface between the information consumer and the MVC "Controller"/"Model" combination. A Java tool set is described for exploring alternative views into the underlying complex data structures encountered in systems engineering.

  13. Visualization aided system of hydropower engineering management%Visualization aided system of hydropower engineering management

    Institute of Scientific and Technical Information of China (English)

    Huang Yuan; Nie Miaojing; Yan Hongyan

    2012-01-01

    For the purpose of realizing the information visualization of hydropower engineering management, we construeted three kinds of graphics models sorted by hierarchy for system modelling, employed the construction simulation system to simulate the real-time construction behaviours, introduced the graphics rendering system to organize and update the virtual scene, and designed the interaction system to respond to the user-initiated and simulation-initiated events. So, the real-time, interactive visualization aided system of hydropower engineering management is developed. Eventually, the effectiveness and capabilities of the system are showed through the application examples in China.

  14. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This brochure describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  15. High Performance Interactive System Dynamics Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Duckworth, Jonathan C [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-14

    This presentation describes a system dynamics simulation (SD) framework that supports an end-to-end analysis workflow that is optimized for deployment on ESIF facilities(Peregrine and the Insight Center). It includes (I) parallel and distributed simulation of SD models, (ii) real-time 3D visualization of running simulations, and (iii) comprehensive database-oriented persistence of simulation metadata, inputs, and outputs.

  16. Autonomous facial recognition system inspired by human visual system based logarithmical image visualization technique

    Science.gov (United States)

    Wan, Qianwen; Panetta, Karen; Agaian, Sos

    2017-05-01

    Autonomous facial recognition system is widely used in real-life applications, such as homeland border security, law enforcement identification and authentication, and video-based surveillance analysis. Issues like low image quality, non-uniform illumination as well as variations in poses and facial expressions can impair the performance of recognition systems. To address the non-uniform illumination challenge, we present a novel robust autonomous facial recognition system inspired by the human visual system based, so called, logarithmical image visualization technique. In this paper, the proposed method, for the first time, utilizes the logarithmical image visualization technique coupled with the local binary pattern to perform discriminative feature extraction for facial recognition system. The Yale database, the Yale-B database and the ATT database are used for computer simulation accuracy and efficiency testing. The extensive computer simulation demonstrates the method's efficiency, accuracy, and robustness of illumination invariance for facial recognition.

  17. Visual Awareness Is Limited by the Representational Architecture of the Visual System.

    Science.gov (United States)

    Cohen, Michael A; Nakayama, Ken; Konkle, Talia; Stantić, Mirta; Alvarez, George A

    2015-11-01

    Visual perception and awareness have strict limitations. We suggest that one source of these limitations is the representational architecture of the visual system. Under this view, the extent to which items activate the same neural channels constrains the amount of information that can be processed by the visual system and ultimately reach awareness. Here, we measured how well stimuli from different categories (e.g., faces and cars) blocked one another from reaching awareness using two distinct paradigms that render stimuli invisible: visual masking and continuous flash suppression. Next, we used fMRI to measure the similarity of the neural responses elicited by these categories across the entire visual hierarchy. Overall, we found strong brain-behavior correlations within the ventral pathway, weaker correlations in the dorsal pathway, and no correlations in early visual cortex (V1-V3). These results suggest that the organization of higher level visual cortex constrains visual awareness and the overall processing capacity of visual cognition.

  18. Evaluation vademecum for visual information system

    Science.gov (United States)

    Santini, Simone

    1999-12-01

    This paper presents some methodological observations on the measurement of performance in Visual Information Retrieval systems. The paper identifies three different types of measures tow of which can be determined with methods inherited from physical and social sciences respectively. The third model is more typical of the design and construction of complicated systems, since it allows us to measure the performance of individual modules before their insertion in a particular application. This paper present some methodologies for the decontextualized evaluation, anchoring them to a case study of evaluation of several subsystems of an image database.

  19. A comparative study of changes operated by sympathetic nervous system activation on spindle afferent discharge and on tonic vibration reflex in rabbit jaw muscles.

    Science.gov (United States)

    Passatore, M; Deriu, F; Grassi, C; Roatta, S

    1996-03-07

    The effect of sympathetic activation on the spindle afferent response to vibratory stimuli eliciting the tonic vibration reflex in jaw closing muscles was studied in precollicularly decerebrate rabbits. Stimulation of the cervical sympathetic trunk, at frequencies within the physiologic range, consistently induced a decrease in spindle response to muscle vibration, which was often preceded by a transient enhancement. Spindle discharge was usually correlated with the EMG activity in the masseter muscle and the tension reflexly developed by jaw muscles. The changes in spindle response to vibration were superimposed on variations of the basal discharge which exhibited different patterns in the studied units, increases in the firing rate being more frequently observed. These effects were mimicked by close arterial injection of the selective alpha 1-adrenoceptor agonist phenylephrine. Data presented here suggest that sympathetically-induced modifications of the tonic vibration reflex are due to changes exerted on muscle spindle afferent information.

  20. Gut vagal afferents differentially modulate innate anxiety and learned fear.

    Science.gov (United States)

    Klarer, Melanie; Arnold, Myrtha; Günther, Lydia; Winter, Christine; Langhans, Wolfgang; Meyer, Urs

    2014-05-21

    Vagal afferents are an important neuronal component of the gut-brain axis allowing bottom-up information flow from the viscera to the CNS. In addition to its role in ingestive behavior, vagal afferent signaling has been implicated modulating mood and affect, including distinct forms of anxiety and fear. Here, we used a rat model of subdiaphragmatic vagal deafferentation (SDA), the most complete and selective vagal deafferentation method existing to date, to study the consequences of complete disconnection of abdominal vagal afferents on innate anxiety, conditioned fear, and neurochemical parameters in the limbic system. We found that compared with Sham controls, SDA rats consistently displayed reduced innate anxiety-like behavior in three procedures commonly used in preclinical rodent models of anxiety, namely the elevated plus maze test, open field test, and food neophobia test. On the other hand, SDA rats exhibited increased expression of auditory-cued fear conditioning, which specifically emerged as attenuated extinction of conditioned fear during the tone re-exposure test. The behavioral manifestations in SDA rats were associated with region-dependent changes in noradrenaline and GABA levels in key areas of the limbic system, but not with functional alterations in the hypothalamus-pituitary-adrenal grand stress. Our study demonstrates that innate anxiety and learned fear are both subjected to visceral modulation through abdominal vagal afferents, possibly via changing limbic neurotransmitter systems. These data add further weight to theories emphasizing an important role of afferent visceral signals in the regulation of emotional behavior.

  1. 30 CFR 77.309 - Visual check of system equipment.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Visual check of system equipment. 77.309... COAL MINES Thermal Dryers § 77.309 Visual check of system equipment. Frequent visual checks shall be made by the operator of the thermal dryer system control station, or by some other competent person,...

  2. Holodeck: Telepresence Dome Visualization System Simulations

    Science.gov (United States)

    Hite, Nicolas

    2012-01-01

    This paper explores the simulation and consideration of different image-projection strategies for the Holodeck, a dome that will be used for highly immersive telepresence operations in future endeavors of the National Aeronautics and Space Administration (NASA). Its visualization system will include a full 360 degree projection onto the dome's interior walls in order to display video streams from both simulations and recorded video. Because humans innately trust their vision to precisely report their surroundings, the Holodeck's visualization system is crucial to its realism. This system will be rigged with an integrated hardware and software infrastructure-namely, a system of projectors that will relay with a Graphics Processing Unit (GPU) and computer to both project images onto the dome and correct warping in those projections in real-time. Using both Computer-Aided Design (CAD) and ray-tracing software, virtual models of various dome/projector geometries were created and simulated via tracking and analysis of virtual light sources, leading to the selection of two possible configurations for installation. Research into image warping and the generation of dome-ready video content was also conducted, including generation of fisheye images, distortion correction, and the generation of a reliable content-generation pipeline.

  3. ATTENTIONAL NETWORKS AND SELECTIVE VISUAL SYSTEM

    Directory of Open Access Journals (Sweden)

    ALEJANDRO CASTILLO MORENO

    2006-05-01

    Full Text Available In this paper we checked the principal researches and theories to explain the attention system functioning.We are going to start reviewing along time about the concept of attention, from filter theories andresources distributor theories, to the current theories in which attention is conceived as a control system.From this last point of view, we will emphasize on the attentional networks theory of Posner, thatproposes different systems to explain diverse aspects of attention, but they are related to each other. Atlast in this paper, we will mention experimental results that have been important to characterize theselective attentional mechanisms of the human visual system, using the attentional spotlight model forthis aim.

  4. Plasticity in the Drosophila larval visual System

    Directory of Open Access Journals (Sweden)

    Abud J Farca-Luna

    2013-07-01

    Full Text Available The remarkable ability of the nervous system to modify its structure and function is mostly experience and activity modulated. The molecular basis of neuronal plasticity has been studied in higher behavioral processes, such as learning and memory formation. However, neuronal plasticity is not restricted to higher brain functions, but may provide a basic feature of adaptation of all neural circuits. The fruit fly Drosophila melanogaster provides a powerful genetic model to gain insight into the molecular basis of nervous system development and function. The nervous system of the larvae is again a magnitude simpler than its adult counter part, allowing the genetic assessment of a number of individual genetically identifiable neurons. We review here recent progress on the genetic basis of neuronal plasticity in developing and functioning neural circuits focusing on the simple visual system of the Drosophila larva.

  5. Pharmacology of airway afferent nerve activity

    Directory of Open Access Journals (Sweden)

    Carr Michael J

    2001-05-01

    Full Text Available Abstract Afferent nerves in the airways serve to regulate breathing pattern, cough, and airway autonomic neural tone. Pharmacologic agents that influence afferent nerve activity can be subclassified into compounds that modulate activity by indirect means (e.g. bronchial smooth muscle spasmogens and those that act directly on the nerves. Directly acting agents affect afferent nerve activity by interacting with various ion channels and receptors within the membrane of the afferent terminals. Whether by direct or indirect means, most compounds that enter the airspace will modify afferent nerve activity, and through this action alter airway physiology.

  6. Surprising characteristics of visual systems of invertebrates.

    Science.gov (United States)

    González-Martín-Moro, J; Hernández-Verdejo, J L; Jiménez-Gahete, A E

    2017-01-01

    To communicate relevant and striking aspects about the visual system of some close invertebrates. Review of the related literature. The capacity of snails to regenerate a complete eye, the benefit of the oval shape of the compound eye of many flying insects as a way of stabilising the image during flight, the potential advantages related to the extreme refractive error that characterises the ocelli of many insects, as well as the ability to detect polarised light as a navigation system, are some of the surprising capabilities present in the small invertebrate eyes that are described in this work. The invertebrate eyes have capabilities and sensorial modalities that are not present in the human eye. The study of the eyes of these animals can help us to improve our understanding of our visual system, and inspire the development of optical devices. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Neuroanatomical affiliation visualization-interface system.

    Science.gov (United States)

    Palombi, Olivier; Shin, Jae-Won; Watson, Charles; Paxinos, George

    2006-01-01

    A number of knowledge management systems have been developed to allow users to have access to large quantity of neuroanatomical data. The advent of three-dimensional (3D) visualization techniques allows users to interact with complex 3D object. In order to better understand the structural and functional organization of the brain, we present Neuroanatomical Affiliations Visualization-Interface System (NAVIS) as the original software to see brain structures and neuroanatomical affiliations in 3D. This version of NAVIS has made use of the fifth edition of "The Rat Brain in Stereotaxic coordinates" (Paxinos and Watson, 2005). The NAVIS development environment was based on the scripting language name Python, using visualization toolkit (VTK) as 3D-library and wxPython for the graphic user interface. The following manuscript is focused on the nucleus of the solitary tract (Sol) and the set of affiliated structures in the brain to illustrate the functionality of NAVIS. The nucleus of the Sol is the primary relay center of visceral and taste information, and consists of 14 distinct subnuclei that differ in cytoarchitecture, chemoarchitecture, connections, and function. In the present study, neuroanatomical projection data of the rat Sol were collected from selected literature in PubMed since 1975. Forty-nine identified projection data of Sol were inserted in NAVIS. The standard XML format used as an input for affiliation data allows NAVIS to update data online and/or allows users to manually change or update affiliation data. NAVIS can be extended to nuclei other than Sol.

  8. Real-Time Visualization System for Computational Offloading

    Science.gov (United States)

    2015-01-01

    dependencies are hard- coded into the visualization system. The remainder of this report is organized as follows. In Section 2, we discuss the...timer. Such a driver has access to all the visualization functionality present in the visualization pane. In Fig. 8, we show a code snippet required...Real-Time Visualization System for Computational Offloading by Bryan Dawson and David L Doria ARL-TN-0655 January 2015

  9. Altered anterior visual system development following early monocular enucleation

    Directory of Open Access Journals (Sweden)

    Krista R. Kelly

    2014-01-01

    Conclusions: The novel finding of an asymmetry in morphology of the anterior visual system following long-term survival from early monocular enucleation indicates altered postnatal visual development. Possible mechanisms behind this altered development include recruitment of deafferented cells by crossing nasal fibres and/or geniculate cell retention via feedback from primary visual cortex. These data highlight the importance of balanced binocular input during postnatal maturation for typical anterior visual system morphology.

  10. Visualization for understanding of neurodynamical systems.

    Science.gov (United States)

    Duch, Włodzisław; Dobosz, Krzysztof

    2011-06-01

    Complex neurodynamical systems are quite difficult to analyze and understand. New type of plots are introduced to help in visualization of high-dimensional trajectories and show global picture of the phase space, including relations between basins of attractors. Color recurrence plots (RPs) display distances from each point on the trajectory to all other points in a two-dimensional matrix. Fuzzy Symbolic Dynamics (FSD) plots enhance this information mapping the whole trajectory to two or three dimensions. Each coordinate is defined by the value of a fuzzy localized membership function, optimized to visualize interesting features of the dynamics, showing to which degree a point on the trajectory belongs to some neighborhood. The variance of the trajectory within the attraction basin plotted against the variance of the synaptic noise provides information about sizes and shapes of these basins. Plots that use color to show the distance between each trajectory point and a larger number of selected reference points (for example centers of attractor basins) are also introduced. Activity of 140 neurons in the semantic layer of dyslexia model implemented in the Emergent neural simulator is analyzed in details showing different aspects of neurodynamics that may be understood in this way. Influence of connectivity and various neural properties on network dynamics is illustrated using visualization techniques. A number of interesting conclusions about cognitive neurodynamics of lexical concept activations are drawn. Changing neural accommodation parameters has very strong influence on the dwell time of the trajectories. This may be linked to attention deficits disorders observed in autism in case of strong enslavement, and to ADHD-like behavior in case of weak enslavement.

  11. A Visualization System for Interactive Exploration of the Cardiac Anatomy.

    Science.gov (United States)

    Zhang, Lei; Wang, Kuanquan; Yang, Fei; Lu, Wenjing; Wang, Kechao; Zhang, Yue; Liang, Xiaoqing; Han, Dongchen; Zhu, Ying Julie

    2016-06-01

    Because of the complex and fine structure, visualization of the heart still remains a challenging task, which makes it an active research topic. In this paper, we present a visualization system for medical data, which takes advantage of the recent graphics processing unit (GPU) and can provide real-time cardiac visualization. This work focuses on investigating the anatomical structure visualization of the human heart, which is fundamental to the cardiac visualization, medical training and diagnosis assistance. Several state-of-the-art cardiac visualization methods are integrated into the proposed system and a task specified visualization method is proposed. In addition, auxiliary tools are provided to generate user specified visualization results. The contributions of our work lie in two-fold: for doctors and medical staff, the system can provide task specified visualization with interactive visualization tools; for researchers, the proposed platform can serve as a baseline for comparing different rendering methods and can easily incorporate new rendering methods. Experimental results show that the proposed system can provide favorable cardiac visualization results in terms of both effectiveness and efficiency.

  12. 40 CFR 202.22 - Visual exhaust system inspection.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Visual exhaust system inspection. 202... Standards § 202.22 Visual exhaust system inspection. No motor carrier subject to these regulations shall operate any motor vehicle of a type to which this regulation is applicable unless the exhaust system...

  13. IMAGO Visualization System: An Interactive Web-Based 3D Visualization System for Cultural Heritage Applications

    Directory of Open Access Journals (Sweden)

    Caroline M. Mendes

    2012-04-01

    Full Text Available Due to the evolution of technologies and methods for realistic 3D reconstruction of objects, in many projects it can be found efficient ways to make research results in digital preservation available on the Internet. 3D visualization of cultural heritage is highlighted in this scenario, helping to expand research activities in this field by providing proper tools to allow for example, remote access to historical artifacts. Thus, visualization systems must be able to handle important aspects in the context of digital preservation, such as user profiles, security and ease access to 3D models. This paper presents the development of an effective web-based 3D visualization system whose architecture offers an easy and fast interactivity with 3D models even when limited computer resources are available. The system has been successfully adopted in developing of 3D Virtual Museums in the Universidade Federal do Parana (UFPR in Brazil, providing an important tool to promote research, educational, social and cultural activities.

  14. Computer systems and methods for visualizing data

    Science.gov (United States)

    Stolte, Chris; Hanrahan, Patrick

    2010-07-13

    A method for forming a visual plot using a hierarchical structure of a dataset. The dataset comprises a measure and a dimension. The dimension consists of a plurality of levels. The plurality of levels form a dimension hierarchy. The visual plot is constructed based on a specification. A first level from the plurality of levels is represented by a first component of the visual plot. A second level from the plurality of levels is represented by a second component of the visual plot. The dataset is queried to retrieve data in accordance with the specification. The data includes all or a portion of the dimension and all or a portion of the measure. The visual plot is populated with the retrieved data in accordance with the specification.

  15. Cascaded effects of spatial adaptation in the early visual system.

    Science.gov (United States)

    Dhruv, Neel T; Carandini, Matteo

    2014-02-05

    Virtually all stages of the visual system exhibit adaptation: neurons adjust their responses based on the recent stimulus history. While some of these adjustments occur at specific stages, others may be inherited from earlier stages. How do adaptation effects cascade along the visual system? We measured spatially selective adaptation at two successive stages in the mouse visual system: visual thalamus (LGN) and primary visual cortex (V1). This form of adaptation affected both stages but in drastically different ways: in LGN it only changed response gain, while in V1 it also shifted spatial tuning away from the adaptor. These effects, however, are reconciled by a simple model whereby V1 neurons summate LGN inputs with a fixed, unadaptable weighting profile. These results indicate that adaptation effects cascade through the visual system, that this cascading can shape selectivity, and that the rules of integration from one stage to the next are not themselves adaptable.

  16. Visualization

    OpenAIRE

    Balon, Andreja

    1990-01-01

    The present thesis entails the field of visualization which is divided into visualization along traditional lines and visualization in computer science. As the psychological aspect of image is of vital importance for visualization, it is shortly described in the beginning. Visualization in computer science is divided into three main fields: scientific visualization, program visualization and visual programming. An explanation and examples of approach to applications are given for each field....

  17. Design and Implementation of Flight Visual Simulation System

    OpenAIRE

    Tian, Feng; Chai, Wenjian; Wang, Chuanyun; Sun, Xiaoping

    2012-01-01

    The design requirement for flight visual simulation system is studied and the overall structure and development process are proposed in this paper. Through the construction of 3D scene model library and aircraft model, the rendering and interaction of visual scene are implemented. The changes of aircraft flight attitude in visual system are controlled by real-time calculation of aircraft aerodynamic and dynamic equations and flight simulation effect is enhanced by this kind of control. Severa...

  18. A dual working mode mobile robot system based on visual guiding and visual servoing

    Institute of Scientific and Technical Information of China (English)

    Peng Yizhun; Yuan Kui; Zou Wei; Hu Huosheng

    2007-01-01

    A dual operational modes mobile robot system based on visual guiding and visual servo control is presented.This system consists of a mobile robot with a two-axis manipulator and a tele-operation station.In the visual guiding mode,for the robot works in an open loop visual servo control mode,the manipulating burden of the operator is reduced largely.In the visual servo mode the robot can locate the position of the target assigned by the operator and pick it up by its manipulator.With the help of the operator,the difficult problems of finding and handling a target in a complicated environment by the robot Can be solved easily.

  19. Activation of lateral geniculate nucleus and primary visual cortex as detected by functional magnetic resonance imaging in normal subjects and in patients with visual disturbance

    Energy Technology Data Exchange (ETDEWEB)

    Miki, Atsushi [Niigata Univ. (Japan). Graduate School of Medical and Dental Sciences

    2002-12-01

    Functional magnetic resonance imaging (fMRI) during visual stimulation can detect regional cerebral blood flow changes that reflect neural activity in the lateral geniculate nucleus and primary visual cortex, which are major relay points in the human afferent visual system. FMRI has been used in the clinical evaluation of visual disorders such as homonymous hemianopia and unilateral eye diseases (optic neuritis, amblyopia, and so on). Future development in the data acquisition and data analysis may facilitate the use of fMRI for the management of patients with visual deficits and understanding of the visual disorders. (author)

  20. Masking reveals parallel form systems in the visual brain

    National Research Council Canada - National Science Library

    Lo, Yu Tung; Zeki, Semir

    2014-01-01

    ...-selective cells of V1. In this psychophysical study, we undertook to test another hypothesis, namely that the brain's visual form system consists of multiple parallel systems and that complex forms are other than the sum of their parts...

  1. History of visual systems in the Systems Engineering Simulator

    Science.gov (United States)

    Christianson, David C.

    1989-01-01

    The Systems Engineering Simulator (SES) houses a variety of real-time computer generated visual systems. The earliest machine dates from the mid-1960's and is one of the first real-time graphics systems in the world. The latest acquisition is the state-of-the-art Evans and Sutherland CT6. Between the span of time from the mid-1960's to the late 1980's, tremendous strides have been made in the real-time graphics world. These strides include advances in both software and hardware engineering. The purpose is to explore the history of the development of these real-time computer generated image systems from the first machine to the present. Hardware advances as well as software algorithm changes are presented. This history is not only quite interesting but also provides us with a perspective with which we can look backward and forward.

  2. Development of an automatic visual grading system for grafting seedlings

    Directory of Open Access Journals (Sweden)

    Subo Tian

    2017-01-01

    Full Text Available In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

  3. An Effective Stereo Visualization System Implementation for Virtual Prototyping

    OpenAIRE

    R.S. Kamath; Dr. R.K. Kamat

    2010-01-01

    Virtual Reality technology is becoming an increasingly popular in diverse areas from scientific data analysis to entertainment. An important feature of this technology is the Stereoscopic display of computer-generated images to produce three-dimensional visual effects. The visualization tool is an ASCII text file driven system to visually simulate the modeled operation in 3D virtual space. Stereovision improves the manufacturing process by analyzing the product before its actual manufacturing...

  4. Chicken (Gallus domesticus) inner ear afferents

    Science.gov (United States)

    Hara, H.; Chen, X.; Hartsfield, J. F.; Hara, J.; Martin, D.; Fermin, C. D.

    1998-01-01

    Neurons from the vestibular (VG) and the statoacoustic (SAG) ganglion of the chick (Gallus domesticus) were evaluated histologically and morphometrically. Embryos at stages 34 (E8 days), 39 (E13 days) and 44 (E18 days) were sacrificed and temporal bones microdissected. Specimens were embedded in JB-4 methacrylate plastic, and stained with a mixture of 0.2% toluidine blue (TB) and 0.1% basic Fuschin in 25% ethanol or with a mixture of 2% TB and 1% paraphenylenediamine (PDA) for axon and myelin measurement study. Images of the VIIIth nerve were produced by a V150 (R) color imaging system and the contour of 200-300 neuronal bodies (perikarya) was traced directly on a video screen with a mouse in real time. The cross-sectional area of VG perikarya was 67.29 micrometers2 at stage 34 (E8), 128.46 micrometers2 at stage 39 (E13) and 275.85 micrometers2 at stage 44 (E18). The cross-sectional area of SAG perikarya was 62.44 micrometers2 at stage 34 (E8), 102.05 micrometers2 at stage 39 (E13) and 165.02 micrometers2 at stage 44 (E18). A significant cross-sectional area increase of the VG perikarya between stage 39 (E13) and stage 44 (E18) was determined. We randomly measured the cross-sectional area of myelin and axoplasm of hatchling afferent nerves, and found a correspondence between axoplasmic and myelin cross-sectional area in the utricular, saccular and semicircular canal nerve branches of the nerve. The results suggest that the period between stage 34 (E8) and 39 (E13) is a critical period for afferent neuronal development. Physiological and behavioral vestibular properties of developing and maturing hatchlings may change accordingly. The results compliment previous work by other investigators and provide valuable anatomical measures useful to correlate physiological data obtained from stimulation of the whole nerve or its parts.

  5. An annotation system for 3D fluid flow visualization

    Science.gov (United States)

    Loughlin, Maria M.; Hughes, John F.

    1995-01-01

    Annotation is a key activity of data analysis. However, current systems for data analysis focus almost exclusively on visualization. We propose a system which integrates annotations into a visualization system. Annotations are embedded in 3D data space, using the Post-it metaphor. This embedding allows contextual-based information storage and retrieval, and facilitates information sharing in collaborative environments. We provide a traditional database filter and a Magic Lens filter to create specialized views of the data. The system has been customized for fluid flow applications, with features which allow users to store parameters of visualization tools and sketch 3D volumes.

  6. Lipolysis sensation by white fat afferent nerves triggers brown fat thermogenesis.

    Science.gov (United States)

    Garretson, John T; Szymanski, Laura A; Schwartz, Gary J; Xue, Bingzhong; Ryu, Vitaly; Bartness, Timothy J

    2016-08-01

    Metabolic challenges, such as a cold environment, stimulate sympathetic neural efferent activity to white adipose tissue (WAT) to drive lipolysis, thereby increasing the availability of free fatty acids as one source of fuel for brown adipose tissue (BAT) thermogenesis. WAT is also innervated by sensory nerve fibers that network to metabolic brain areas; moreover, activation of these afferents is reported to increase sympathetic nervous system outflow. However, the endogenous stimuli sufficient to drive WAT afferents during metabolic challenges as well as their functional relation to BAT thermogenesis remain unknown. We tested if local WAT lipolysis directly activates WAT afferent nerves, and then assessed whether this WAT sensory signal affected BAT thermogenesis in Siberian hamsters (Phodopus sungorus). 2-deoxyglucose, a sympathetic nervous system stimulant, caused β-adrenergic receptor dependent increases in inguinal WAT (IWAT) afferent neurophysiological activity. In addition, direct IWAT injections of the β3-AR agonist CL316,243 dose-dependently increased: 1) phosphorylation of IWAT hormone sensitive lipase, an indicator of SNS-stimulated lipolysis, 2) expression of the neuronal activation marker c-Fos in dorsal root ganglion neurons receiving sensory input from IWAT, and 3) IWAT afferent neurophysiological activity, an increase blocked by antilipolytic agent 3,5-dimethylpyrazole. Finally, we demonstrated that IWAT afferent activation by lipolysis triggers interscapular BAT thermogenesis through a neural link between these two tissues. These data suggest IWAT lipolysis activates local IWAT afferents triggering a neural circuit from WAT to BAT that acutely induces BAT thermogenesis.

  7. Visualizing Astrophysical N-body Systems

    CERN Document Server

    Dubinski, John

    2008-01-01

    I begin with a brief history of N-body simulation and visualization and then go on to describe various methods for creating images and animations of modern simulations in cosmology and galactic dynamics. These techniques are incorporated into a specialized particle visualization software library called MYRIAD that is designed to render images within large parallel N-body simulations as they run. I present several case studies that explore the application of these methods to animations of star clusters, interacting galaxies and cosmological structure formation.

  8. Disappearance of click-evoked potentials on the neck of the guinea pig by pharmacological and surgical destruction of the peripheral vestibular afferent system.

    Science.gov (United States)

    Matsuzaki, Masaki; Murofushi, Toshihisa

    2003-10-01

    In order to establish an animal model of acoustically evoked vestibulo-collic reflex, the so-called vestibular evoked myogenic potential in humans, potentials evoked by loud clicks on the neck of the guinea pig were recorded using subjects whose peripheral vestibular endorgans or vestibular afferents had been damaged. Four normal control guinea pigs, four guinea pigs that received an intramuscular injection of gentamicin for 20 days (90 mg/kg/day) and five guinea pigs whose vestibular nerves were surgically sectioned were used in this study. Under general anesthesia with an intraperitoneal injection of pentobarbital sodium (40 mg/kg), auditory brainstem responses (ABRs) were recorded. Then, potentials evoked by loud clicks on the pre-vertebral muscle at the level of the third cervical vertebral bone were recorded using silver ball electrodes. As a result, a distinctive negative peak (NP) with a latency of 6-8 ms was recorded in all animals in the control group. NP was not observed in the gentamicin-administered group while ABR was preserved. After sectioning the vestibular nerve, NP was abolished while ABR was preserved. From these results, NP could be of vestibular origin. These results are in agreement with a previous report of NP using subjects whose cochlea had been damaged pharmacologically.

  9. Lipopolysaccharide-induced hyperalgesia of intracranial capsaicin sensitive afferents in conscious rats

    NARCIS (Netherlands)

    Kemper, RHA; Spoelstra, MB; Meijler, WJ; Ter Horst, GJ

    1998-01-01

    Migraineous and non-migraineous headache is reported to be at highest intensity after an infection. This study investigated whether activation of the immune system can induce hyperalgesia in intracranial capsaicin sensitive afferents. The effects of intraperitoneal injected lipopolysaccharides (LPS)

  10. JPEG2000 COMPRESSION CODING USING HUMAN VISUAL SYSTEM MODEL

    Institute of Scientific and Technical Information of China (English)

    Xiao Jiang; Wu Chengke

    2005-01-01

    In order to apply the Human Visual System (HVS) model to JPEG2000 standard,several implementation alternatives are discussed and a new scheme of visual optimization isintroduced with modifying the slope of rate-distortion. The novelty is that the method of visual weighting is not lifting the coefficients in wavelet domain, but is complemented by code stream organization. It remains all the features of Embedded Block Coding with Optimized Truncation (EBCOT) such as resolution progressive, good robust for error bit spread and compatibility of lossless compression. Well performed than other methods, it keeps the shortest standard codestream and decompression time and owns the ability of VIsual Progressive (VIP) coding.

  11. Flight simulation visual requirements and a new display system

    Science.gov (United States)

    Amery, John G.; Streid, Harry R.

    1999-08-01

    This paper reviews the technical requirements for Out The Window (OTW) visual systems. Requirements for different modes of training and/or simulation will be stated. A new type of visual display will be described that provides improved, cost effective implementation and performance.

  12. An approach for the development of visual configuration systems

    DEFF Research Database (Denmark)

    Hvam, Lars; Ladeby, Klaes Rohde

    2007-01-01

    by Centre for Product Modelling (CPM) at The Technical University of Denmark. The approach is based on experiences from a visualization project in co-operation between CPM and the global provider of power protection American Power Conversion (APC). The visual configuration system was developed in 2001...

  13. Formalism for the Neural Network of Visual Systems

    NARCIS (Netherlands)

    Stavenga, D.G.; Beersma, D.G.M.

    1975-01-01

    A formalism to describe neural interrelations is developed on the exemplary case of the fly visual system. Absolute and relative indices are employed to identify the position of neural elements within the lattices of the visual ganglia. Illustrative applications as the projection of fly retinula cel

  14. Integrating visual learning within a model-based ATR system

    Science.gov (United States)

    Carlotto, Mark; Nebrich, Mark

    2017-05-01

    Automatic target recognition (ATR) systems, like human photo-interpreters, rely on a variety of visual information for detecting, classifying, and identifying manmade objects in aerial imagery. We describe the integration of a visual learning component into the Image Data Conditioner (IDC) for target/clutter and other visual classification tasks. The component is based on an implementation of a model of the visual cortex developed by Serre, Wolf, and Poggio. Visual learning in an ATR context requires the ability to recognize objects independent of location, scale, and rotation. Our method uses IDC to extract, rotate, and scale image chips at candidate target locations. A bootstrap learning method effectively extends the operation of the classifier beyond the training set and provides a measure of confidence. We show how the classifier can be used to learn other features that are difficult to compute from imagery such as target direction, and to assess the performance of the visual learning process itself.

  15. [Auditory guidance systems for the visually impaired people].

    Science.gov (United States)

    He, Jing; Nie, Min; Luo, Lan; Tong, Shanbao; Niu, Jinhai; Zhu, Yisheng

    2010-04-01

    Visually impaired people face many inconveniences because of the loss of vision. Therefore, scientists are trying to design various guidance systems for improving the lives of the blind. Based on sensory substitution, auditory guidance has become an interesting topic in the field of biomedical engineering. In this paper, we made a state-of-technique review of the auditory guidance system. Although there have been many technical challenges, the auditory guidance system would be a useful alternative for the visually impaired people.

  16. Local control of information flow in segmental and ascending collaterals of single afferents.

    Science.gov (United States)

    Lomelí, J; Quevedo, J; Linares, P; Rudomin, P

    1998-10-08

    In the vertebrate spinal cord, the activation of GABA(gamma-amino-butyric acid)-releasing interneurons that synapse with intraspinal terminals of sensory fibres leading into the central nervous system (afferent fibres) produces primary afferent depolarization and presynaptic inhibition. It is not known to what extent these presynaptic mechanisms allow a selective control of information transmitted through specific sets of intraspinal branches of individual afferents. Here we study the local nature of the presynaptic control by measuring primary afferent depolarization simultaneously in two intraspinal collaterals of the same muscle spindle afferent. One of these collaterals ends at the L6-L7 segmental level in the intermediate nucleus, and the other ascends to segment L3 within Clarke's column, the site of origin of spinocerebellar neurons. Our results indicate that there are central mechanisms that are able to affect independently the synaptic effectiveness of segmental and ascending collaterals of individual muscle spindle afferents. Focal control of presynaptic inhibition thus allows the intraspinal branches of afferent fibres to function as a dynamic assembly that can be fractionated to convey information to selected neuronal targets. This may be a mechanism by which different spinal postsynaptic targets that are coupled by sensory input from a common source could be uncoupled.

  17. Distribution of presumptive chemosensory afferents with FMRFamide- or substance P-like immunoreactivity in decapod crustaceans.

    Science.gov (United States)

    Schmidt, M

    1997-01-23

    In five species of decapod crustaceans--Cherax destructor (crayfish), Carcinus maenas (crab), Homarus americanus (clawed lobster), Eriocheir sinensis (crab), Macrobrachium rosenbergii (shrimp)--immunocytochemical stainings revealed the presence of sensory afferents with FMRFamide-like immunoreactivity in the central nervous system. These afferents were extremely thin, very numerous, and innervated all sensory neuropils except the optic and olfactory lobes. In their target neuropils they gave rise to condensed net- or ball-like terminal structures. Only in Homarus americanus but not in any other studied species immunocytochemistry revealed a separate, non-overlapping class of sensory afferents with substance P-like immunoreactivity. Also the afferents with substance P-like immunoreactivity were very thin and numerous, innervated all sensory neuropils except optic and olfactory lobes, and gave rise to condensed terminal structures. From their morphological characteristics it can be concluded that likely both classes of afferents are chemosensory. The substance P-like immunoreactivity suggests a link with the nociceptor afferents of vertebrates, with which both classes of afferents share several other morphological features.

  18. Dynamic response to initial stage blindness in visual system development.

    Science.gov (United States)

    Long, Erping; Zhang, Xiayin; Liu, Zhenzhen; Wu, Xiaohang; Tan, Xuhua; Lin, Duoru; Cao, Qianzhong; Chen, Jingjing; Lin, Zhuoling; Wang, Dongni; Li, Xiaoyan; Li, Jing; Wang, Jinghui; Li, Wangting; Lin, Haotian; Chen, Weirong; Liu, Yizhi

    2017-07-01

    Sensitive periods and experience-dependent plasticity have become core issues in visual system development. Converging evidence indicates that visual experience is an indispensable factor in establishing mature visual system circuitry during sensitive periods and the visual system exhibits substantial plasticity while facing deprivation. The mechanisms that underlie the environmental regulation of visual system development and plasticity are of great interest but need further exploration. Here, we investigated a unique sample of human infants who experienced initial stage blindness (beginning at birth and lasting for 2-8 months) before the removal of bilateral cataracts. Retinal thickness (RT), axial length (AL), refractive status, visual grating acuity and genetic integrity were recorded during the preoperative period or at surgery and then during follow-up. The results showed that the development of the retina is malleable and associated with external environmental influences. Our work supported that the retina might play critical roles in the development of the experience-dependent visual system and its malleability might partly contribute to the sensitive period plasticity. © 2017 The Author(s).

  19. Psychophysical Criteria for Visual Simulation Systems.

    Science.gov (United States)

    1980-05-01

    differences ( aniseikonia ) encompass a variety of visual display problems in which the images to the two eyes differ. These disparities are categorized...displacements is treated in the discussion of binocular image rotation. The topic of unequal magnification ( aniseikonia ), which has been the subject of much...The specific functional relationships needinq quantification were the following: 1. The effect of Horizontal Aniseikonia on Target Detection and

  20. Visual Data Mining in Indian Election System

    Directory of Open Access Journals (Sweden)

    Prof. T. M. Kodinariya

    2012-07-01

    Full Text Available A good leaders or Government is the basic need to develop country. In India, who is largest democratic country in the world people are not fully involved in the selection process of Leaders. On an average there are 60-65% voting is done. For this purpose we have build the Data Warehouse that containing all the information related to election to increase awareness of voting. Using this we can findinteresting patterns that are extracted and represented using Visual Data mining to arrange awareness program. The approach is divided into 5 phases: I Data Preprocessing: II Data Warehouse Creation:III Task-Relevant Data Extraction; IV Data Mining and V Visualization. Generally, data collected from various cities of a state may be noisy, inconsistent and requires cleaning hence the database is preprocessed for missing values, normalization etc. in first phase. In Data Warehouse Creation phase, warehouse with vote as measure in fact and voter Gender, voter age, voter education, candidate, Religion, time, session, word as dimension. Word dimension has 4-level concept hierarchy of country, state, city, area/word id. Time dimension has concept hierarchy with year, Quarter, month, and date. Similarly, candidate has 2 level and Voter age, voter education, Religion, and session have level 1 concept hierarchy. In Last phase, results of data mining phase are represented using Visual Data mining techniques.

  1. Multiple Roles for Nogo Receptor 1 in Visual System Plasticity.

    Science.gov (United States)

    Stephany, Céleste-Élise; Frantz, Michael G; McGee, Aaron W

    2016-12-01

    During the developmental critical period for visual plasticity, discordant vision alters the responsiveness of neurons in visual cortex. The subsequent closure of the critical period not only consolidates neural function but also limits recovery of acuity from preceding abnormal visual experience. Despite species-specific differences in circuitry of the visual system, these characteristics are conserved. The nogo-66 receptor 1 (ngr1) is one of only a small number of genes identified thus far that is essential to closing the critical period. Mice lacking a functional ngr1 gene retain developmental visual plasticity as adults and their visual acuity spontaneously improves after prolonged visual deprivation. Experiments employing conditional mouse genetics have revealed that ngr1 restricts plasticity within distinct circuits for ocular dominance and visual acuity. However, the mechanisms by which NgR1 limits plasticity have not been elucidated, in part because the subcellular localization and signal transduction of the protein are only partially understood. Here we explore potential mechanisms for NgR1 function in relation to manipulations that reactivate visual plasticity in adults and propose lines of investigation to address relevant gaps in knowledge.

  2. Eye movement-invariant representations in the human visual system.

    Science.gov (United States)

    Nishimoto, Shinji; Huth, Alexander G; Bilenko, Natalia Y; Gallant, Jack L

    2017-01-01

    During natural vision, humans make frequent eye movements but perceive a stable visual world. It is therefore likely that the human visual system contains representations of the visual world that are invariant to eye movements. Here we present an experiment designed to identify visual areas that might contain eye-movement-invariant representations. We used functional MRI to record brain activity from four human subjects who watched natural movies. In one condition subjects were required to fixate steadily, and in the other they were allowed to freely make voluntary eye movements. The movies used in each condition were identical. We reasoned that the brain activity recorded in a visual area that is invariant to eye movement should be similar under fixation and free viewing conditions. In contrast, activity in a visual area that is sensitive to eye movement should differ between fixation and free viewing. We therefore measured the similarity of brain activity across repeated presentations of the same movie within the fixation condition, and separately between the fixation and free viewing conditions. The ratio of these measures was used to determine which brain areas are most likely to contain eye movement-invariant representations. We found that voxels located in early visual areas are strongly affected by eye movements, while voxels in ventral temporal areas are only weakly affected by eye movements. These results suggest that the ventral temporal visual areas contain a stable representation of the visual world that is invariant to eye movements made during natural vision.

  3. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker;

    2014-01-01

    Due to increased computational power, reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between a HRTF enhanced audio system (3D......) and an amplitude panning audio system (panning) in a virtual environment. We present a performance study involving 33 participants locating aurally-aided visual targets placed at fixed positions, under different audio conditions. A varying amount of visual distractors were present, represented as black circles...

  4. Three-dimensional visualization and animation for power systems analysis

    Energy Technology Data Exchange (ETDEWEB)

    Milano, Federico [Department of Electrical Engineering of the University of Castilla-La Mancha, 13071, Ciudad Real (Spain)

    2009-12-15

    This paper describes a novel approach for three-dimensional visualization and animation of power systems analyses. The paper demonstrates that three-dimensional visualization of power systems can be used for teaching and can help in easily understanding complex concepts. The solutions of power flow analysis, continuation power flow, optimal power flow and time domain simulations are used for illustrating the proposed technique. The paper presents a variety of examples, particularly oriented to education and practitioner training. Conclusions are duly drawn. (author)

  5. Retinal and visual system: occupational and environmental toxicology.

    Science.gov (United States)

    Fox, Donald A

    2015-01-01

    Occupational chemical exposure often results in sensory systems alterations that occur without other clinical signs or symptoms. Approximately 3000 chemicals are toxic to the retina and central visual system. Their dysfunction can have immediate, long-term, and delayed effects on mental health, physical health, and performance and lead to increased occupational injuries. The aims of this chapter are fourfold. First, provide references on retinal/visual system structure, function, and assessment techniques. Second, discuss the retinal features that make it especially vulnerable to toxic chemicals. Third, review the clinical and corresponding experimental data regarding retinal/visual system deficits produced by occupational toxicants: organic solvents (carbon disulfide, trichloroethylene, tetrachloroethylene, styrene, toluene, and mixtures) and metals (inorganic lead, methyl mercury, and mercury vapor). Fourth, discuss occupational and environmental toxicants as risk factors for late-onset retinal diseases and degeneration. Overall, the toxicants altered color vision, rod- and/or cone-mediated electroretinograms, visual fields, spatial contrast sensitivity, and/or retinal thickness. The findings elucidate the importance of conducting multimodal noninvasive clinical, electrophysiologic, imaging and vision testing to monitor toxicant-exposed workers for possible retinal/visual system alterations. Finally, since the retina is a window into the brain, an increased awareness and understanding of retinal/visual system dysfunction should provide additional insight into acquired neurodegenerative disorders.

  6. Sunfall: a collaborative visual analytics system for astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Aragon, Cecilia R.; Aragon, Cecilia R.; Bailey, Stephen J.; Poon, Sarah; Runge, Karl; Thomas, Rollin C.

    2008-07-07

    Computational and experimental sciences produce and collect ever-larger and complex datasets, often in large-scale, multi-institution projects. The inability to gain insight into complex scientific phenomena using current software tools is a bottleneck facing virtually all endeavors of science. In this paper, we introduce Sunfall, a collaborative visual analytics system developed for the Nearby Supernova Factory, an international astrophysics experiment and the largest data volume supernova search currently in operation. Sunfall utilizes novel interactive visualization and analysis techniques to facilitate deeper scientific insight into complex, noisy, high-dimensional, high-volume, time-critical data. The system combines novel image processing algorithms, statistical analysis, and machine learning with highly interactive visual interfaces to enable collaborative, user-driven scientific exploration of supernova image and spectral data. Sunfall is currently in operation at the Nearby Supernova Factory; it is the first visual analytics system in production use at a major astrophysics project.

  7. Workflow Driven Decision Support Systems: A case of an intra-operative visualization system for surgeons

    NARCIS (Netherlands)

    Jalote-Parmar, A.

    2009-01-01

    Inadequate visualization during Minimally Invasive Surgeries (MIS) has led several technology research labs to develop decision support systems such as Intra-operative Visualization Systems (IVS). IVS focuses on providing surgeons with real-time imaging support to improve task visualization and

  8. The Two Visual Systems Hypothesis: new challenges and insights from visual form agnosic patient DF

    Directory of Open Access Journals (Sweden)

    Robert Leslie Whitwell

    2014-12-01

    Full Text Available Patient DF, who developed visual form agnosia following carbon monoxide poisoning, is still able to use vision to adjust the configuration of her grasping hand to the geometry of a goal object. This striking dissociation between perception and action in DF provided a key piece of evidence for the formulation of Goodale and Milner’s Two Visual Systems Hypothesis (TVSH. According to the TVSH, the ventral stream plays a critical role in constructing our visual percepts, whereas the dorsal stream mediates the visual control of action, such as visually guided grasping. In this review, we discuss recent studies of DF that provide new insights into the functional organization of the dorsal and ventral streams. We confirm recent evidence that DF has dorsal as well as ventral brain damage – and that her dorsal-stream lesions and surrounding atrophy have increased in size since her first published brain scan. We argue that the damage to DF’s dorsal stream explains her deficits in directing actions at targets in the periphery. We then focus on DF’s ability to accurately adjust her in-flight hand aperture to changes in the width of goal objects (grip scaling whose dimensions she cannot explicitly report. An examination of several studies of DF’s grip scaling under natural conditions reveals a modest though significant deficit. Importantly, however, she continues to show a robust dissociation between form vision for perception and form vision for action. We also review recent studies that explore the role of online visual feedback and terminal haptic feedback in the programming and control of her grasping. These studies make it clear that DF is no more reliant on visual or haptic feedback than are neurologically-intact individuals. In short, we argue that her ability to grasp objects depends on visual feedforward processing carried out by visuomotor networks in her dorsal stream that function in the much the same way as they do in neurologically

  9. Shared visual attention and memory systems in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Bruno van Swinderen

    Full Text Available BACKGROUND: Selective attention and memory seem to be related in human experience. This appears to be the case as well in simple model organisms such as the fly Drosophila melanogaster. Mutations affecting olfactory and visual memory formation in Drosophila, such as in dunce and rutabaga, also affect short-term visual processes relevant to selective attention. In particular, increased optomotor responsiveness appears to be predictive of visual attention defects in these mutants. METHODOLOGY/PRINCIPAL FINDINGS: To further explore the possible overlap between memory and visual attention systems in the fly brain, we screened a panel of 36 olfactory long term memory (LTM mutants for visual attention-like defects using an optomotor maze paradigm. Three of these mutants yielded high dunce-like optomotor responsiveness. We characterized these three strains by examining their visual distraction in the maze, their visual learning capabilities, and their brain activity responses to visual novelty. We found that one of these mutants, D0067, was almost completely identical to dunce(1 for all measures, while another, D0264, was more like wild type. Exploiting the fact that the LTM mutants are also Gal4 enhancer traps, we explored the sufficiency for the cells subserved by these elements to rescue dunce attention defects and found overlap at the level of the mushroom bodies. Finally, we demonstrate that control of synaptic function in these Gal4 expressing cells specifically modulates a 20-30 Hz local field potential associated with attention-like effects in the fly brain. CONCLUSIONS/SIGNIFICANCE: Our study uncovers genetic and neuroanatomical systems in the fly brain affecting both visual attention and odor memory phenotypes. A common component to these systems appears to be the mushroom bodies, brain structures which have been traditionally associated with odor learning but which we propose might be also involved in generating oscillatory brain activity

  10. Synchronization trigger control system for flow visualization

    Science.gov (United States)

    Chun, K. S.

    1987-01-01

    The use of cinematography or holographic interferometry for dynamic flow visualization in an internal combustion engine requires a control device that globally synchronizes camera and light source timing at a predefined shaft encoder angle. The device is capable of 0.35 deg resolution for rotational speeds of up to 73 240 rpm. This was achieved by implementing the shaft encoder signal addressed look-up table (LUT) and appropriate latches. The developed digital signal processing technique achieves 25 nsec of high speed triggering angle detection by using direct parallel bit comparison of the shaft encoder digital code with a simulated angle reference code, instead of using angle value comparison which involves more complicated computation steps. In order to establish synchronization to an AC reference signal whose magnitude is variant with the rotating speed, a dynamic peak followup synchronization technique has been devised. This method scrutinizes the reference signal and provides the right timing within 40 nsec. Two application examples are described.

  11. Defining the cortical visual systems: "what", "where", and "how"

    Science.gov (United States)

    Creem, S. H.; Proffitt, D. R.; Kaiser, M. K. (Principal Investigator)

    2001-01-01

    The visual system historically has been defined as consisting of at least two broad subsystems subserving object and spatial vision. These visual processing streams have been organized both structurally as two distinct pathways in the brain, and functionally for the types of tasks that they mediate. The classic definition by Ungerleider and Mishkin labeled a ventral "what" stream to process object information and a dorsal "where" stream to process spatial information. More recently, Goodale and Milner redefined the two visual systems with a focus on the different ways in which visual information is transformed for different goals. They relabeled the dorsal stream as a "how" system for transforming visual information using an egocentric frame of reference in preparation for direct action. This paper reviews recent research from psychophysics, neurophysiology, neuropsychology and neuroimaging to define the roles of the ventral and dorsal visual processing streams. We discuss a possible solution that allows for both "where" and "how" systems that are functionally and structurally organized within the posterior parietal lobe.

  12. The Orbital Maneuvering Vehicle Training Facility visual system concept

    Science.gov (United States)

    Williams, Keith

    1989-01-01

    The purpose of the Orbital Maneuvering Vehicle (OMV) Training Facility (OTF) is to provide effective training for OMV pilots. A critical part of the training environment is the Visual System, which will simulate the video scenes produced by the OMV Closed-Circuit Television (CCTV) system. The simulation will include camera models, dynamic target models, moving appendages, and scene degradation due to the compression/decompression of video signal. Video system malfunctions will also be provided to ensure that the pilot is ready to meet all challenges the real-world might provide. One possible visual system configuration for the training facility that will meet existing requirements is described.

  13. Expression of 5-HT3 receptors by extrinsic duodenal afferents contribute to intestinal inhibition of gastric emptying.

    Science.gov (United States)

    Raybould, Helen E; Glatzle, Jorg; Robin, Carla; Meyer, James H; Phan, Thomas; Wong, Helen; Sternini, Catia

    2003-03-01

    Intestinal perfusion with carbohydrates inhibits gastric emptying via vagal and spinal capsaicin-sensitive afferent pathways. The aim of the present study was to determine the role of 1) 5-hydroxytryptamine (5-HT)(3) receptors (5-HT(3)R) in mediating glucose-induced inhibition of gastric emptying and 2) 5-HT(3)R expression in vagal and spinal afferents in innervating the duodenum. In awake rats fitted with gastric and duodenal cannulas, perfusion of the duodenum with glucose (50 and 100 mg) inhibited gastric emptying. Intestinal perfusion of mannitol inhibited gastric emptying only at the highest concentration (990 mosm/kgH(2)O). Pretreatment with the 5-HT(3)R antagonist tropisetron abolished both glucose- and mannitol-induced inhibition of gastric emptying. Retrograde labeling of visceral afferents by injection of dextran-conjugated Texas Red into the duodenal wall was used to identify extrinsic primary afferents. Immunoreactivity for 5-HT(3)R, visualized with an antibody directed to the COOH terminus of the rat 5-HT(3)R, was found in >80% of duodenal vagal and spinal afferents. These results show that duodenal extrinsic afferents express 5-HT(3)R and that the receptor mediates specific glucose-induced inhibition of gastric emptying. These findings support the hypothesis that enterochromaffin cells in the intestinal mucosa release 5-HT in response to glucose, which activates 5-HT(3)R on afferent nerve terminals to evoke reflex changes in gastric motility. The primary glucose sensors of the intestine may be mucosal enterochromaffin cells.

  14. Enhanced Muscle Afferent Signals during Motor Learning in Humans.

    Science.gov (United States)

    Dimitriou, Michael

    2016-04-25

    Much has been revealed concerning human motor learning at the behavioral level [1, 2], but less is known about changes in the involved neural circuits and signals. By examining muscle spindle responses during a classic visuomotor adaptation task [3-6] performed by fully alert humans, I found substantial modulation of sensory afferent signals as a function of adaptation state. Specifically, spindle control was independent of concurrent muscle activity but was specific to movement direction (representing muscle lengthening versus shortening) and to different stages of learning. Increased spindle afferent responses to muscle stretch occurring early during learning reflected individual error size and were negatively related to subsequent antagonist activity (i.e., 60-80 ms thereafter). Relative increases in tonic afferent output early during learning were predictive of the subjects' adaptation rate. I also found that independent spindle control during sensory realignment (the "washout" stage) induced afferent signal "linearization" with respect to muscle length (i.e., signals were more tuned to hand position). The results demonstrate for the first time that motor learning also involves independent and state-related modulation of sensory mechanoreceptor signals. The current findings suggest that adaptive motor performance also relies on the independent control of sensors, not just of muscles. I propose that the "γ" motor system innervating spindles acts to facilitate the acquisition and extraction of task-relevant information at the early stages of sensorimotor adaptation. This designates a more active and targeted role for the human proprioceptive system during motor learning.

  15. Voice and GPS Based Navigation System For Visually Impaired

    Directory of Open Access Journals (Sweden)

    Harsha Gawari

    2014-04-01

    Full Text Available The paper represents the architecture and implementation of a system that will help to navigate the visually impaired people. The system designed uses GPS and voice recognition along with obstacle avoidance for the purpose of guiding visually impaired. The visually impaired person issues the command and receives the direction response using audio signals. The latitude and longitude values are received continuously from the GPS receiver. The directions are given to the user with the help of audio signals. An obstacle detector is used to help the user to avoid obstacles by sending an audio message.GPS receivers use NMEA standard. With the advancement in voice recognition it becomes easier to issue commands regarding directions to the visually impaired.

  16. Visual disturbance with systemic symptoms: old lessons revisited.

    Science.gov (United States)

    Hume, Megan E; Fernandes, Peter M; MacLean, Kirsty; McRorie, Euan; Davenport, Richard

    2016-10-25

    We describe a retired physician who presented with visual disturbance and systemic symptoms. The presence of general malaise, headache and scalp tenderness, with raised inflammatory markers, suggested that giant cell arteritis (GCA) was the likely diagnosis. Rapid response to initial steroid therapy and histological evidence of inflammation in the temporal artery supported this diagnosis. The character of these visual symptoms was, however, atypical for GCA. The patient, who had heart valve disease, subsequently deteriorated and developed further symptoms warranting investigation of bacterial endocarditis. Retinal emboli are a recognised complication of endocarditis, which could account for these visual symptoms. Moreover, interpretation of the temporal artery biopsy is limited in the context of existing steroid therapy. Our patient was consequently diagnosed with bacterial endocarditis. This case reminds us to consider the wider differential diagnoses for headache, visual disturbance and systemic symptoms, where echocardiogram and blood cultures may be crucial to reach the diagnosis.

  17. An Effective Stereo Visualization System Implementation for Virtual Prototyping

    Directory of Open Access Journals (Sweden)

    R.S. Kamath

    2010-10-01

    Full Text Available Virtual Reality technology is becoming an increasingly popular in diverse areas from scientific data analysis to entertainment. An important feature of this technology is the Stereoscopic display of computer-generated images to produce three-dimensional visual effects. The visualization tool is an ASCII text file driven system to visually simulate the modeled operation in 3D virtual space. Stereovision improves the manufacturing process by analyzing the product before its actual manufacturing. The goal of the virtual prototyping environment is to decrease product development time and costs and also to increase quality by providing continuous computer support for the development cycle. This paper addresses implementation of 3D stereo visualization system which serves in virtual prototyping for productivity improvement in Manufacturing Processes.

  18. Rapidly Building Visual Management Systems for Context-Aware Services

    Science.gov (United States)

    Satoh, Ichiro

    A component framework for building and operating visual interfaces for context-aware services in ubiquitous computing environments is presented. By using a compound-document technology, it provides physical entities, places, stationary or mobile computing devices, and services with visual components as multimedia representations to enable them to be annotated and controlled them. It can automatically assemble visual components into a visual interface for monitoring and managing context-aware services according to the spatial-containment relationships between their targets in the physical world by using underlying location-sensing systems. End-users can manually deploy and customize context-aware services through user-friendly GUI-based manipulations for editing documents. This paper presents the design for this framework and describes its implementation and practical applications in user/location-aware assistant systems in two museums.

  19. Associating peripheral and foveal visual input across saccades: a default mode of the human visual system?

    Science.gov (United States)

    Weiß, Katharina; Schneider, Werner X; Herwig, Arvid

    2014-09-09

    Spatial processing resolution of a particular object in the visual field can differ considerably due to eye movements. The same object will be represented with high acuity in the fovea but only coarsely in periphery. Herwig and Schneider (in press) proposed that the visual system counteracts such resolution differences by predicting, based on previous experience, how foveal objects will look in the periphery and vice versa. They demonstrated that previously learned transsaccadic associations between peripheral and foveal object information facilitate performance in visual search, irrespective of the correctness of these associations. False associations were learned by replacing the presaccadic object with a slightly different object during the saccade. Importantly, participants usually did not notice this object change. This raises the question of whether perception of object continuity is a critical factor in building transsaccadic associations. We disturbed object continuity during learning with a postsaccadic blank or a task-irrelevant shape change. Interestingly, visual search performance revealed that neither disruption of temporal object continuity (blank) nor disruption of spatial object continuity (shape change) impaired transsaccadic learning. Thus, transsaccadic learning seems to be a very robust default mechanism of the visual system that is probably related to the more general concept of action-effect learning.

  20. Innervation of enteric mast cells by primary spinal afferents in guinea pig and human small intestine.

    Science.gov (United States)

    Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Qu, Meihua; Xia, Yun; Needleman, Bradley J; Mikami, Dean J; Wood, Jackie D

    2014-10-01

    Mast cells express the substance P (SP) neurokinin 1 receptor and the calcitonin gene-related peptide (CGRP) receptor in guinea pig and human small intestine. Enzyme-linked immunoassay showed that activation of intramural afferents by antidromic electrical stimulation or by capsaicin released SP and CGRP from human and guinea pig intestinal segments. Electrical stimulation of the afferents evoked slow excitatory postsynaptic potentials (EPSPs) in the enteric nervous system. The slow EPSPs were mediated by tachykinin neurokinin 1 and CGRP receptors. Capsaicin evoked slow EPSP-like responses that were suppressed by antagonists for protease-activated receptor 2. Afferent stimulation evoked slow EPSP-like excitation that was suppressed by mast cell-stabilizing drugs. Histamine and mast cell protease II were released by 1) exposure to SP or CGRP, 2) capsaicin, 3) compound 48/80, 4) elevation of mast cell Ca²⁺ by ionophore A23187, and 5) antidromic electrical stimulation of afferents. The mast cell stabilizers cromolyn and doxantrazole suppressed release of protease II and histamine when evoked by SP, CGRP, capsaicin, A23187, electrical stimulation of afferents, or compound 48/80. Neural blockade by tetrodotoxin prevented mast cell protease II release in response to antidromic electrical stimulation of mesenteric afferents. The results support a hypothesis that afferent innervation of enteric mast cells releases histamine and mast cell protease II, both of which are known to act in a diffuse paracrine manner to influence the behavior of enteric nervous system neurons and to elevate the sensitivity of spinal afferent terminals.

  1. Visual Debugging of Visualization Software: A Case Study for Particle Systems

    Energy Technology Data Exchange (ETDEWEB)

    Angel, Edward; Crossno, Patricia

    1999-07-12

    Visualization systems are complex dynamic software systems. Debugging such systems is difficult using conventional debuggers because the programmer must try to imagine the three-dimensional geometry based on a list of positions and attributes. In addition, the programmer must be able to mentally animate changes in those positions and attributes to grasp dynamic behaviors within the algorithm. In this paper we shall show that representing geometry, attributes, and relationships graphically permits visual pattern recognition skills to be applied to the debugging problem. The particular application is a particle system used for isosurface extraction from volumetric data. Coloring particles based on individual attributes is especially helpful when these colorings are viewed as animations over successive iterations in the program. Although we describe a particular application, the types of tools that we discuss can be applied to a variety of problems.

  2. Visualizing Concurrency Control Algorithms for Real-Time Database Systems

    Directory of Open Access Journals (Sweden)

    Olusegun Folorunso

    2008-11-01

    Full Text Available This paper describes an approach to visualizing concurrency control (CC algorithms for real-time database systems (RTDBs. This approach is based on the principle of software visualization, which has been applied in related fields. The Model-View-controller (MVC architecture is used to alleviate the black box syndrome associated with the study of algorithm behaviour for RTDBs Concurrency Controls. We propose a Visualization "exploratory" tool that assists the RTDBS designer in understanding the actual behaviour of the concurrency control algorithms of choice and also in evaluating the performance quality of the algorithm. We demonstrate the feasibility of our approach using an optimistic concurrency control model as our case study. The developed tool substantiates the earlier simulation-based performance studies by exposing spikes at some points when visualized dynamically that are not observed using usual static graphs. Eventually this tool helps solve the problem of contradictory assumptions of CC in RTDBs.

  3. Visualization tool. 3DAVS and polarization-type VR system

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Yasuhiro [Fujitsu Tokushima Systems Engineering Limited, Tokushima (Japan); Ueshima, Yutaka [Japan Atomic Energy Research Inst., Kizu, Kyoto (Japan)

    2003-01-01

    In the visualization work of simulation data in every advanced research field, what is used most in the report or the presentation as a research result has still remained in the stages of the still picture or the 2-dimensional animation, in spite of recent abundance of various visualization software. With the recent progress of computational environment, however, more complicated phenomena can be so easily computed that the results are more needed to be comprehensible as well as intelligible. Therefore, it inevitably requires an animation rather than a still picture, or 3-dimensional display (virtual reality) rather than 2-dimensional one. In this report, two visualization tools, 3DAVS and Polarization-Type VR system are described as the data expression method after visualization processing. (author)

  4. VisTool: A user interface and visualization development system

    DEFF Research Database (Denmark)

    Xu, Shangjin

    Although software usability has long been emphasized, there is a lot of software with poor usability. In Usability Engineering, usability professionals prescribe a classical usability approach to improving software usability. It is essential to prototype and usability test user interfaces before....... However, it is more difficult to follow the classical usability approach for graphical presentation development. These difficulties result from the fact that designers cannot implement user interface with interactions and real data. We developed VisTool – a user interface and visualization development...... system – to simplify user interface development. VisTool allows user interface development without real programming. With VisTool a designer assembles visual objects (e.g. textboxes, ellipse, etc.) to visualize database contents. In VisTool, visual properties (e.g. color, position, etc.) can be formulas...

  5. Plasticity and stability of the visual system in human achiasma.

    Science.gov (United States)

    Hoffmann, Michael B; Kaule, Falko R; Levin, Netta; Masuda, Yoichiro; Kumar, Anil; Gottlob, Irene; Horiguchi, Hiroshi; Dougherty, Robert F; Stadler, Joerg; Wolynski, Barbara; Speck, Oliver; Kanowski, Martin; Liao, Yaping J; Wandell, Brian A; Dumoulin, Serge O

    2012-08-09

    The absence of the optic chiasm is an extraordinary and extreme abnormality in the nervous system. The abnormality produces highly atypical functional responses in the cortex, including overlapping hemifield representations and bilateral population receptive fields in both striate and extrastriate visual cortex. Even in the presence of these large functional abnormalities, the effect on visual perception and daily life is not easily detected. Here, we demonstrate that in two achiasmic humans the gross topography of the geniculostriate and occipital callosal connections remains largely unaltered. We conclude that visual function is preserved by reorganization of intracortical connections instead of large-scale reorganizations of the visual cortex. Thus, developmental mechanisms of local wiring within cortical maps compensate for the improper gross wiring to preserve function in human achiasma.

  6. Visualization and natural control systems for microscopy

    DEFF Research Database (Denmark)

    Taylor, Russell M.; Borland, David; Brooks, Frederick P.

    2005-01-01

    This chapter presents these microscope systems, along with brief descriptions of the science experiments driving the development of each system. Beginning with a discussion of the philosophy that has driven the Nanoscale Science Research Group (NSRG) and the methods used, the chapter describes...... the lessons learned during system development, including both useful directions and blind alleys. The first lesson is to begin software development at least as soon as hardware development. The second lesson is to partner with experts in required technologies. The NSRG attempts to use the best available...... computer technology to develop effective systems for use by the physical science team, which then become cost-effective and can be deployed on widely available hardware as technology marches on. The chapter also describes techniques to enable telemicroscopy in the context of remote experiments and outreach...

  7. Spectral Imaging Visualization and Tracking System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address the NASA Earth Observation Mission need for innovative optical tracking systems, Physical Optics Corporation (POC) proposes to develop a new Spectral...

  8. Experience-independent development of the hamster circadian visual system.

    Directory of Open Access Journals (Sweden)

    August Kampf-Lassin

    Full Text Available Experience-dependent functional plasticity is a hallmark of the primary visual system, but it is not known if analogous mechanisms govern development of the circadian visual system. Here we investigated molecular, anatomical, and behavioral consequences of complete monocular light deprivation during extended intervals of postnatal development in Syrian hamsters. Hamsters were raised in constant darkness and opaque contact lenses were applied shortly after eye opening and prior to the introduction of a light-dark cycle. In adulthood, previously-occluded eyes were challenged with visual stimuli. Whereas image-formation and motion-detection were markedly impaired by monocular occlusion, neither entrainment to a light-dark cycle, nor phase-resetting responses to shifts in the light-dark cycle were affected by prior monocular deprivation. Cholera toxin-b subunit fluorescent tract-tracing revealed that in monocularly-deprived hamsters the density of fibers projecting from the retina to the suprachiasmatic nucleus (SCN was comparable regardless of whether such fibers originated from occluded or exposed eyes. In addition, long-term monocular deprivation did not attenuate light-induced c-Fos expression in the SCN. Thus, in contrast to the thalamocortical projections of the primary visual system, retinohypothalamic projections terminating in the SCN develop into normal adult patterns and mediate circadian responses to light largely independent of light experience during development. The data identify a categorical difference in the requirement for light input during postnatal development between circadian and non-circadian visual systems.

  9. Retinal waves coordinate patterned activity throughout the developing visual system.

    Science.gov (United States)

    Ackman, James B; Burbridge, Timothy J; Crair, Michael C

    2012-10-11

    The morphological and functional development of the vertebrate nervous system is initially governed by genetic factors and subsequently refined by neuronal activity. However, fundamental features of the nervous system emerge before sensory experience is possible. Thus, activity-dependent development occurring before the onset of experience must be driven by spontaneous activity, but the origin and nature of activity in vivo remains largely untested. Here we use optical methods to show in live neonatal mice that waves of spontaneous retinal activity are present and propagate throughout the entire visual system before eye opening. This patterned activity encompassed the visual field, relied on cholinergic neurotransmission, preferentially initiated in the binocular retina and exhibited spatiotemporal correlations between the two hemispheres. Retinal waves were the primary source of activity in the midbrain and primary visual cortex, but only modulated ongoing activity in secondary visual areas. Thus, spontaneous retinal activity is transmitted through the entire visual system and carries patterned information capable of guiding the activity-dependent development of complex intra- and inter-hemispheric circuits before the onset of vision.

  10. Segmentation of moving images by the human visual system.

    Science.gov (United States)

    Chantelau, K

    1997-08-01

    New segments appearing in an image sequence or spontaneously accelerated segments are band limited by the visual system due to a nonperfect tracking of these segments by eye movements. In spite of this band limitation and acceleration of segments, a coarse segmentation (initial segmentation phase) can be performed by the visual system. This is interesting for the development of purely automatic segmentation algorithms for multimedia applications. In this paper the segmentation of the visual system is modelled and used in an automatic coarse initial segmentation. A suitable model for motion processing based on a spectral representation is presented and applied to the segmentation of synthetic and real image sequences with band limited and accelerated moving foreground and background segments.

  11. Effect of hypergravity on the development of vestibulocerebellar afferent fibers

    Science.gov (United States)

    Bruce, L. L.

    Gravity is a critical factor in the normal development of the vestibular system, as prolonged prenatal exposures to either micro- or hypergravity will alter the pattern of projections from specific vestibular organs to specific targets in the vestibular nuclei. This study addresses the effect of gravity on the development of vestibulocerebellar projections. In adult rats the semicircular canal afferents project mainly to the cerebellar nodulus whereas the otolith maculae project mainly to the ventral uvula of the cerebellum. To determine if the distribution pattern of these afferents is altered by exposures to altered gravity, 10 pregnant rats were exposed to hypergravity (1.5g) from embryonic day 12 (before vestibular ganglion neurons contact vestibular nuclei) to embryonic day 21 (near the time when the vestibular system becomes functional). Controls were exposed to Earth's gravity but otherwise received the same treatment. At the end of the exposure the embryos were deeply anesthetized and fixed by transcardiac perfusion with 4% paraformaldehyde in 0.1 M phosphate buffer (pH7.4). Filter strips coated with DiI and PTIR were implanted into the saccule (gravistatic vestibular receptor) or into the posterior vertical canal (angular acceleration receptor), and allowed to diffuse for 2 weeks at 37°C. Then the brains were dissected and sectioned for fluorescent confocal imaging. Examination of the control cerebella revealed that the canal and otolith afferents have reached the nodulus and uvula, and axons extend into the internal granular, Purkinje, and molecular layers. Projections from the saccule and posterior vertical canal were partially segregated into their respective domains, the uvula and nodulus. In contrast, in hypergravity-exposed rat fetuses the saccule and posterior vertical canal projections were poorly segregated, and both organs contributed labeled fibers to all layers of the nodulus and uvula. This contrasts with the increased afferent segregation

  12. The coordinate systems used in visual tracking

    NARCIS (Netherlands)

    Howe, P.D.L.; Pinto, Y.; Horowitz, T.S.

    2010-01-01

    Tracking moving objects is a fundamental attentional operation. Here we ask which coordinate system is used to track objects: retinal (retinotopic), scene-centered (allocentric), or both? Observers tracked three of six disks that were confined to move within an imaginary square. By moving either the

  13. Visuals and Visualisation of Human Body Systems

    Science.gov (United States)

    Mathai, Sindhu; Ramadas, Jayashree

    2009-01-01

    This paper explores the role of diagrams and text in middle school students' understanding and visualisation of human body systems. We develop a common framework based on structure and function to assess students' responses across diagram and verbal modes. Visualisation is defined in terms of understanding transformations on structure and relating…

  14. Research Requirements for Future Visual Guidance Systems

    Science.gov (United States)

    1994-02-01

    20591. 5. FAA Advisory Circular 150/5340-18, Standards for Airport Sign Systems, latest edition, Washington, DC 20591. 6. Bonaventura , Vincent...Dunlap and Associates, March 1952, New York. 8. Bonaventura , Vincent E., A Proposed Method of Color Coding Airport Taxi Guidance-Sins, The Port of New

  15. Visualization and natural control systems for microscopy

    DEFF Research Database (Denmark)

    Taylor, Russell M.; Borland, David; Brooks, Frederick P.

    2005-01-01

    the lessons learned during system development, including both useful directions and blind alleys. The first lesson is to begin software development at least as soon as hardware development. The second lesson is to partner with experts in required technologies. The NSRG attempts to use the best available...

  16. The unassisted visual system on earth and in space.

    Science.gov (United States)

    Harris, Laurence R; Jenkin, Michael; Jenkin, Heather; Dyde, Richard; Zacher, Jim; Allison, Robert S

    2010-01-01

    Chuck Oman has been a guide and mentor for research in human perception and performance during space exploration for over 25 years. His research has provided a solid foundation for our understanding of how humans cope with the challenges and ambiguities of sensation and perception in space. In many of the environments associated with work in space the human visual system must operate with unusual combinations of visual and other perceptual cues. On Earth physical acceleration cues are normally available to assist the visual system in interpreting static and dynamic visual features. Here we consider two cases where the visual system is not assisted by such cues. Our first experiment examines perceptual stability when the normally available physical cues to linear acceleration are absent. Our second experiment examines perceived orientation when there is no assistance from the physically sensed direction of gravity. In both cases the effectiveness of vision is paradoxically reduced in the absence of physical acceleration cues. The reluctance to rely heavily on vision represents an important human factors challenge to efficient performance in the space environment.

  17. A visualization system for CT based pulmonary fissure analysis

    Science.gov (United States)

    Pu, Jiantao; Zheng, Bin; Park, Sang Cheol

    2009-02-01

    In this study we describe a visualization system of pulmonary fissures depicted on CT images. The purpose is to provide clinicians with an intuitive perception of a patient's lung anatomy through an interactive examination of fissures, enhancing their understanding and accurate diagnosis of lung diseases. This system consists of four key components: (1) region-of-interest segmentation; (2) three-dimensional surface modeling; (3) fissure type classification; and (4) an interactive user interface, by which the extracted fissures are displayed flexibly in different space domains including image space, geometric space, and mixed space using simple toggling "on" and "off" operations. In this system, the different visualization modes allow users not only to examine the fissures themselves but also to analyze the relationship between fissures and their surrounding structures. In addition, the users can adjust thresholds interactively to visualize the fissure surface under different scanning and processing conditions. Such a visualization tool is expected to facilitate investigation of structures near the fissures and provide an efficient "visual aid" for other applications such as treatment planning and assessment of therapeutic efficacy as well as education of medical professionals.

  18. Satellite Imagery Assisted Road-Based Visual Navigation System

    Science.gov (United States)

    Volkova, A.; Gibbens, P. W.

    2016-06-01

    There is a growing demand for unmanned aerial systems as autonomous surveillance, exploration and remote sensing solutions. Among the key concerns for robust operation of these systems is the need to reliably navigate the environment without reliance on global navigation satellite system (GNSS). This is of particular concern in Defence circles, but is also a major safety issue for commercial operations. In these circumstances, the aircraft needs to navigate relying only on information from on-board passive sensors such as digital cameras. An autonomous feature-based visual system presented in this work offers a novel integral approach to the modelling and registration of visual features that responds to the specific needs of the navigation system. It detects visual features from Google Earth* build a feature database. The same algorithm then detects features in an on-board cameras video stream. On one level this serves to localise the vehicle relative to the environment using Simultaneous Localisation and Mapping (SLAM). On a second level it correlates them with the database to localise the vehicle with respect to the inertial frame. The performance of the presented visual navigation system was compared using the satellite imagery from different years. Based on comparison results, an analysis of the effects of seasonal, structural and qualitative changes of the imagery source on the performance of the navigation algorithm is presented. * The algorithm is independent of the source of satellite imagery and another provider can be used

  19. Public Transport Information System for Visually Impaired and Blind People

    Science.gov (United States)

    Markiewicz, Michał; Skomorowski, Marek

    This paper presents an assistive system for the visually impaired and blind people which helps them using public transport means. The proposed system uses mobile phones as a medium for passenger information system and GPS (Global Positioning System), GSM (Global System for Mobile Communications) and Bluetooth technologies for location and communication purposes. In the proposed system sound messages are given to the blind people via mobile phones which have dedicated software installed. This system has been implemented and tested in public transport in two pilot cities.

  20. Characteristics of Flight Simulator Visual Systems

    Science.gov (United States)

    1981-05-01

    d’Eclairage CGI computer- geerated imagery CM modulation contrast -B B2 CRT cathode-ray tube d diameter of aperture, m D luminance transition...photopic vision (for a 20 field) V’(;,) spectral luminosity coefficient for scotopic vision I,2 standardized primry colors in the CIE system X,Y, Z ...transitions should not vary with range to natural features, but should vary with illumina- Z WOODED tion and visibility. Naturally, for a perfectly uni- 2

  1. Power spectra of the natural input to the visual system.

    Science.gov (United States)

    Pamplona, D; Triesch, J; Rothkopf, C A

    2013-05-03

    The efficient coding hypothesis posits that sensory systems are adapted to the regularities of their signal input so as to reduce redundancy in the resulting representations. It is therefore important to characterize the regularities of natural signals to gain insight into the processing of natural stimuli. While measurements of statistical regularity in vision have focused on photographic images of natural environments it has been much less investigated, how the specific imaging process embodied by the organism's eye induces statistical dependencies on the natural input to the visual system. This has allowed using the convenient assumption that natural image data are homogeneous across the visual field. Here we give up on this assumption and show how the imaging process in a human model eye influences the local statistics of the natural input to the visual system across the entire visual field. Artificial scenes with three-dimensional edge elements were generated and the influence of the imaging projection onto the back of a spherical model eye were quantified. These distributions show a strong radial influence of the imaging process on the resulting edge statistics with increasing eccentricity from the model fovea. This influence is further quantified through computation of the second order intensity statistics as a function of eccentricity from the center of projection using samples from the dead leaves image model. Using data from a naturalistic virtual environment, which allows generation of correctly projected images onto the model eye across the entire field of view, we quantified the second order dependencies as function of the position in the visual field using a new generalized parameterization of the power spectra. Finally, we compared this analysis with a commonly used natural image database, the van Hateren database, and show good agreement within the small field of view available in these photographic images. We conclude by providing a detailed

  2. New apparatus of single particle trap system for aerosol visualization

    Science.gov (United States)

    Higashi, Hidenori; Fujioka, Tomomi; Endo, Tetsuo; Kitayama, Chiho; Seto, Takafumi; Otani, Yoshio

    2014-08-01

    Control of transport and deposition of charged aerosol particles is important in various manufacturing processes. Aerosol visualization is an effective method to directly observe light scattering signal from laser-irradiated single aerosol particle trapped in a visualization cell. New single particle trap system triggered by light scattering pulse signal was developed in this study. The performance of the device was evaluated experimentally. Experimental setup consisted of an aerosol generator, a differential mobility analyzer (DMA), an optical particle counter (OPC) and the single particle trap system. Polystylene latex standard (PSL) particles (0.5, 1.0 and 2.0 μm) were generated and classified according to the charge by the DMA. Singly charged 0.5 and 1.0 μm particles and doubly charged 2.0 μm particles were used as test particles. The single particle trap system was composed of a light scattering signal detector and a visualization cell. When the particle passed through the detector, trigger signal with a given delay time sent to the solenoid valves upstream and downstream of the visualization cell for trapping the particle in the visualization cell. The motion of particle in the visualization cell was monitored by CCD camera and the gravitational settling velocity and the electrostatic migration velocity were measured from the video image. The aerodynamic diameter obtained from the settling velocity was in good agreement with Stokes diameter calculated from the electrostatic migration velocity for individual particles. It was also found that the aerodynamic diameter obtained from the settling velocity was a one-to-one function of the scattered light intensity of individual particles. The applicability of this system will be discussed.

  3. Identification of Safety System Malfunction Using Correlation Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Park, Suk Young; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Kim, Jung Taek [KAERI, Dajeon (Korea, Republic of)

    2014-08-15

    I and C systems should provide the reliable information particularly when an accident occurs and operators should also take action to mitigate the accident by identifying the cause of accident. However, incorrect information might be provided due to malfunction or failure of safety system caused by an accident. Accordingly, operators get confused and it made difficult for them to take appropriate actions. If they fail to grasp the exact information of progress then it might lead to spread of accident. Thus, we propose the idea that enables to identify safety system malfunctions or failures in such environment impossible to guarantee of safety system. For identifying the malfunctions or failures of a safety system, the correlation visualization which shows linear relationship between parameters is performed. The correlation visualization results show different images with various scenarios, so it determines which system has problem to operate. Therefore we can identify the safety system operability by the comparison of the correlation visualization results. Furthermore, we can determine specifically which parameter shows abnormal signal using correlation visualization after identifying the operability of safety system. The methodology can determine the situation by viewing the overall signals and include the result robustly though incorrect signal input to the indictor. Proposed methodology is demonstrated through case study by specifying SBLOCA as an initiating event that is judged greater contribution of severe accident. Various accident data are obtained according to operability of safety system and confirmed a feasibility of idea by applying to case study. Overall reliability of I and C system can be improved using suggested methodology. As a result, this research can be helpful in accident response and management if safety system malfunctioned when an accident occurred.

  4. A prototype system based on visual interactive SDM called VGC

    Science.gov (United States)

    Jia, Zelu; Liu, Yaolin; Liu, Yanfang

    2009-10-01

    In many application domains, data is collected and referenced by its geo-spatial location. Spatial data mining, or the discovery of interesting patterns in such databases, is an important capability in the development of database systems. Spatial data mining recently emerges from a number of real applications, such as real-estate marketing, urban planning, weather forecasting, medical image analysis, road traffic accident analysis, etc. It demands for efficient solutions for many new, expensive, and complicated problems. For spatial data mining of large data sets to be effective, it is also important to include humans in the data exploration process and combine their flexibility, creativity, and general knowledge with the enormous storage capacity and computational power of today's computers. Visual spatial data mining applies human visual perception to the exploration of large data sets. Presenting data in an interactive, graphical form often fosters new insights, encouraging the information and validation of new hypotheses to the end of better problem-solving and gaining deeper domain knowledge. In this paper a visual interactive spatial data mining prototype system (visual geo-classify) based on VC++6.0 and MapObject2.0 are designed and developed, the basic algorithms of the spatial data mining is used decision tree and Bayesian networks, and data classify are used training and learning and the integration of the two to realize. The result indicates it's a practical and extensible visual interactive spatial data mining tool.

  5. Visualizing Terrestrial and Aquatic Systems in 3D - in IEEE VisWeek 2014

    Science.gov (United States)

    The need for better visualization tools for environmental science is well documented, and the Visualization for Terrestrial and Aquatic Systems project (VISTAS) aims to both help scientists produce effective environmental science visualizations and to determine which visualizatio...

  6. Visualizing Terrestrial and Aquatic Systems in 3D - in IEEE VisWeek 2014

    Science.gov (United States)

    The need for better visualization tools for environmental science is well documented, and the Visualization for Terrestrial and Aquatic Systems project (VISTAS) aims to both help scientists produce effective environmental science visualizations and to determine which visualizatio...

  7. Audio-visual perception system for a humanoid robotic head.

    Science.gov (United States)

    Viciana-Abad, Raquel; Marfil, Rebeca; Perez-Lorenzo, Jose M; Bandera, Juan P; Romero-Garces, Adrian; Reche-Lopez, Pedro

    2014-05-28

    One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework.

  8. Audio-Visual Perception System for a Humanoid Robotic Head

    Directory of Open Access Journals (Sweden)

    Raquel Viciana-Abad

    2014-05-01

    Full Text Available One of the main issues within the field of social robotics is to endow robots with the ability to direct attention to people with whom they are interacting. Different approaches follow bio-inspired mechanisms, merging audio and visual cues to localize a person using multiple sensors. However, most of these fusion mechanisms have been used in fixed systems, such as those used in video-conference rooms, and thus, they may incur difficulties when constrained to the sensors with which a robot can be equipped. Besides, within the scope of interactive autonomous robots, there is a lack in terms of evaluating the benefits of audio-visual attention mechanisms, compared to only audio or visual approaches, in real scenarios. Most of the tests conducted have been within controlled environments, at short distances and/or with off-line performance measurements. With the goal of demonstrating the benefit of fusing sensory information with a Bayes inference for interactive robotics, this paper presents a system for localizing a person by processing visual and audio data. Moreover, the performance of this system is evaluated and compared via considering the technical limitations of unimodal systems. The experiments show the promise of the proposed approach for the proactive detection and tracking of speakers in a human-robot interactive framework.

  9. A Dynamic Systems Theory Model of Visual Perception Development

    Science.gov (United States)

    Coté, Carol A.

    2015-01-01

    This article presents a model for understanding the development of visual perception from a dynamic systems theory perspective. It contrasts to a hierarchical or reductionist model that is often found in the occupational therapy literature. In this proposed model vision and ocular motor abilities are not foundational to perception, they are seen…

  10. Corner Detection Based on Human Visual System Model

    Institute of Scientific and Technical Information of China (English)

    LU Xiaoguang; ZHOU Jie

    2001-01-01

    Corners are useful features in computer vision tasks.In this paper,we present an algorithm for corner detection based on a human visual system model.Experimental results proved that it ismore effective than conventional corner detector under uneven illumination conditions.

  11. Whisker-related afferents in superior colliculus.

    Science.gov (United States)

    Castro-Alamancos, Manuel A; Favero, Morgana

    2016-05-01

    Rodents use their whiskers to explore the environment, and the superior colliculus is part of the neural circuits that process this sensorimotor information. Cells in the intermediate layers of the superior colliculus integrate trigeminotectal afferents from trigeminal complex and corticotectal afferents from barrel cortex. Using histological methods in mice, we found that trigeminotectal and corticotectal synapses overlap somewhat as they innervate the lower and upper portions of the intermediate granular layer, respectively. Using electrophysiological recordings and optogenetics in anesthetized mice in vivo, we showed that, similar to rats, whisker deflections produce two successive responses that are driven by trigeminotectal and corticotectal afferents. We then employed in vivo and slice experiments to characterize the response properties of these afferents. In vivo, corticotectal responses triggered by electrical stimulation of the barrel cortex evoke activity in the superior colliculus that increases with stimulus intensity and depresses with increasing frequency. In slices from adult mice, optogenetic activation of channelrhodopsin-expressing trigeminotectal and corticotectal fibers revealed that cells in the intermediate layers receive more efficacious trigeminotectal, than corticotectal, synaptic inputs. Moreover, the efficacy of trigeminotectal inputs depresses more strongly with increasing frequency than that of corticotectal inputs. The intermediate layers of superior colliculus appear to be tuned to process strong but infrequent trigeminal inputs and weak but more persistent cortical inputs, which explains features of sensory responsiveness, such as the robust rapid sensory adaptation of whisker responses in the superior colliculus. Copyright © 2016 the American Physiological Society.

  12. Reticulospinal actions on primary afferent depolarization of cutaneous and muscle afferents in the isolated frog neuraxis.

    Science.gov (United States)

    González, H; Jiménez, I; Rudomin, P

    1993-01-01

    The effects of the brainstem reticular formation on the intraspinal excitability of low threshold cutaneous and muscle afferents were studied in the frog neuraxis isolated together with the right hindlimb nerves. Stimulation of low threshold fibers (less than two times threshold) in cutaneous nerves produced short latency, negative field potentials in the ipsilateral dorsal neuropil (200-400 microns depth) that reversed to positivity at deeper regions (500-700 microns). Stimulation of low threshold fibers (less than two times threshold) in muscle nerves produced, instead, negative response that acquired their maximum amplitude in the ventral neuropil (700-900 microns depth). These electrophysiological findings suggest, in agreement with observations in the cat, that low threshold cutaneous and muscle afferents end at different sites in the spinal cord. Intraspinal microstimulation applied within the dorsal neuropil produced antidromic responses in low threshold cutaneous afferents that were increased in size following stimulation of the dorsal or ventral roots, as well as of the brainstem reticular formation. This increase in excitability is interpreted as being due to primary afferent depolarization (PAD) of the intraspinal terminals of cutaneous fibers. Antidromic responses recorded in muscle nerves following intraspinal stimulation within the ventral neuropil were also increased following conditioning stimulation of adjacent dorsal or ventral roots. However, stimulation of the bulbar reticular formation produced practically no changes in the antidromic responses, but was able to inhibit the PAD of low threshold muscle afferents elicited by stimulation of the dorsal or ventral roots. It is suggested that the PAD of low threshold cutaneous and muscle afferents is mediated by independent sets of interneurons. Reticulospinal fibers would have excitatory connections with the interneurons mediating the PAD of cutaneous fibers and inhibitory connections with the

  13. Visual system evolution and the nature of the ancestral snake.

    Science.gov (United States)

    Simões, B F; Sampaio, F L; Jared, C; Antoniazzi, M M; Loew, E R; Bowmaker, J K; Rodriguez, A; Hart, N S; Hunt, D M; Partridge, J C; Gower, D J

    2015-07-01

    The dominant hypothesis for the evolutionary origin of snakes from 'lizards' (non-snake squamates) is that stem snakes acquired many snake features while passing through a profound burrowing (fossorial) phase. To investigate this, we examined the visual pigments and their encoding opsin genes in a range of squamate reptiles, focusing on fossorial lizards and snakes. We sequenced opsin transcripts isolated from retinal cDNA and used microspectrophotometry to measure directly the spectral absorbance of the photoreceptor visual pigments in a subset of samples. In snakes, but not lizards, dedicated fossoriality (as in Scolecophidia and the alethinophidian Anilius scytale) corresponds with loss of all visual opsins other than RH1 (λmax 490-497 nm); all other snakes (including less dedicated burrowers) also have functional sws1 and lws opsin genes. In contrast, the retinas of all lizards sampled, even highly fossorial amphisbaenians with reduced eyes, express functional lws, sws1, sws2 and rh1 genes, and most also express rh2 (i.e. they express all five of the visual opsin genes present in the ancestral vertebrate). Our evidence of visual pigment complements suggests that the visual system of stem snakes was partly reduced, with two (RH2 and SWS2) of the ancestral vertebrate visual pigments being eliminated, but that this did not extend to the extreme additional loss of SWS1 and LWS that subsequently occurred (probably independently) in highly fossorial extant scolecophidians and A. scytale. We therefore consider it unlikely that the ancestral snake was as fossorial as extant scolecophidians, whether or not the latter are para- or monophyletic.

  14. Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

    Directory of Open Access Journals (Sweden)

    André eMaia Chagas

    2013-12-01

    Full Text Available Sensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of ‘how much’ information is conveyed by primary afferents, using the direct method, a classical information theoretic tool, revealed that primary afferents transfer huge amounts of information (up to 529 bits/s. Information theoretic analysis of instantaneous spike-triggered kinematic stimulus features was used to gain functional insight on ‘what’ is coded by primary afferents. Amongst the kinematic variables tested - position, velocity, and acceleration - primary afferent spikes encoded velocity best. The other two variables contribute to information transfer, but only if combined with velocity. We further revealed three additional characteristics that play a role in information transfer by primary afferents. Firstly, primary afferent spikes show preference for well separated multiple stimuli (i.e. well separated sets of combinations of the three instantaneous kinematic variables. Secondly, spikes are sensitive to short strips of the stimulus trajectory (up to 10 ms pre-spike time, and thirdly, they show spike patterns (precise doublet and triplet spiking. In order to deal with these complexities, we used a flexible probabilistic neuron model fitting mixtures of Gaussians to the spike triggered stimulus distributions, which quantitatively captured the contribution of the mentioned features and allowed us to achieve a full functional analysis of the total information rate indicated by the direct method. We found that instantaneous position, velocity, and acceleration explained about 50% of the total information rate. Adding a 10 ms pre-spike interval of stimulus trajectory achieved 80-90%. The final 10-20% were found to be due to non-linear coding by spike bursts.

  15. Visual prosthesis wireless energy transfer system optimal modeling.

    Science.gov (United States)

    Li, Xueping; Yang, Yuan; Gao, Yong

    2014-01-16

    Wireless energy transfer system is an effective way to solve the visual prosthesis energy supply problems, theoretical modeling of the system is the prerequisite to do optimal energy transfer system design. On the basis of the ideal model of the wireless energy transfer system, according to visual prosthesis application condition, the system modeling is optimized. During the optimal modeling, taking planar spiral coils as the coupling devices between energy transmitter and receiver, the effect of the parasitic capacitance of the transfer coil is considered, and especially the concept of biological capacitance is proposed to consider the influence of biological tissue on the energy transfer efficiency, resulting in the optimal modeling's more accuracy for the actual application. The simulation data of the optimal model in this paper is compared with that of the previous ideal model, the results show that under high frequency condition, the parasitic capacitance of inductance and biological capacitance considered in the optimal model could have great impact on the wireless energy transfer system. The further comparison with the experimental data verifies the validity and accuracy of the optimal model proposed in this paper. The optimal model proposed in this paper has a higher theoretical guiding significance for the wireless energy transfer system's further research, and provide a more precise model reference for solving the power supply problem in visual prosthesis clinical application.

  16. Four-dimensional information visualization and analysis system

    Energy Technology Data Exchange (ETDEWEB)

    Rex, B.

    1994-09-01

    4DIVAS was conceived for two purposes. The first purpose was to fill the void between the current generation of GIS and high-end, image-only visualization systems. The gap existing between these two systems can be summarized as the limitation of relational database oriented GIS to deal with time and the poor connection in visualization systems to databases of any kind. The second purpose was to permit spatio-temporal modeling and query, functionalities currently underdeveloped in the commercial arena. At the Hanford Site, there are many potential applications for such a system, especially in the monitoring and modeling of potential constituent plumes in the subsurface hydrology over time, among others. In its current form, 4DIVAS exists as a proof-of-concept functional prototype and is therefore more of a technology than a product at this time.

  17. Visual exploration of 2D autonomous dynamical systems

    CERN Document Server

    Müller, Thomas

    2015-01-01

    In an introductory course on dynamical systems or Hamiltonian mechanics, vector field diagrams are a central tool to show a system's qualitative behaviour in a certain domain. Because of their low sampling rates and the involved issues of vector normalization, these plots give only a coarse insight and are unable to convey the vector field behaviour at locations with high variation, in particular in the neighborhood of critical points. Similarly, automatic generation of phase portraits based on traditional sampling cannot precisely capture separatrices or limit cylces. In this paper, we present ASysViewer, an application for the interactive visual exploration of two-dimensional autonomous dynamical systems using line integral convolution techniques for visualization, and grid-based techniques to extract critical points and separatrices. ASysViewer is addressed to undergraduate students during their first course in dynamical systems or Hamiltonian mechanics.

  18. Head-mounted display system for surgical visualization

    Science.gov (United States)

    Schmidt, Greg W.; Osborn, Dale B.

    1995-05-01

    Recent advances in high resolution color spatial light modulators and light weight optics together with application specific integrated circuits enable true stereoscopic visualization on a head mounted display (HMD). The development of precision stereo displays with comfortable long duration wear characteristics are critically dependent on incorporating key human factors into the HMD design. In this paper we discuss the development of a VGA format (640 X 480 pixel) full color video and graphics stereo display. Its primary application is as an element of an integrated, interactive visualization system for surgeons performing minimally invasive surgery and endoscopic laser surgery. Additional uses include endoscopic and open surgical training and rehearsal. The high resolution, wide field of view displays combined with true stereoscopic imagery enhances the surgeon's visualization, ability to navigate and manipulate in the surgical field.

  19. Visual perception system and method for a humanoid robot

    Science.gov (United States)

    Wells, James W. (Inventor); Mc Kay, Neil David (Inventor); Chelian, Suhas E. (Inventor); Linn, Douglas Martin (Inventor); Wampler, II, Charles W. (Inventor); Bridgwater, Lyndon (Inventor)

    2012-01-01

    A robotic system includes a humanoid robot with robotic joints each moveable using an actuator(s), and a distributed controller for controlling the movement of each of the robotic joints. The controller includes a visual perception module (VPM) for visually identifying and tracking an object in the field of view of the robot under threshold lighting conditions. The VPM includes optical devices for collecting an image of the object, a positional extraction device, and a host machine having an algorithm for processing the image and positional information. The algorithm visually identifies and tracks the object, and automatically adapts an exposure time of the optical devices to prevent feature data loss of the image under the threshold lighting conditions. A method of identifying and tracking the object includes collecting the image, extracting positional information of the object, and automatically adapting the exposure time to thereby prevent feature data loss of the image.

  20. Performance analysis of visual markers for indoor navigation systems#

    Institute of Scientific and Technical Information of China (English)

    Gaetano C LA DELFA; Salvatore MONTELEONE; Vincenzo CATANIA; Juan F DE PAZ; Javier BAJO

    2016-01-01

    The massive diffusion of smartphones, the growing interest in wearable devices and the Internet of Things, and the exponential rise of location based services (LBSs) have made the problem of localization and navigation inside buildings one of the most important technological challenges of recent years. Indoor positioning systems have a huge market in the retail sector and contextual advertising;in addition, they can be fundamental to increasing the quality of life for citizens if deployed inside public buildings such as hospitals, airports, and museums. Sometimes, in emergency situations, they can make the difference between life and death. Various approaches have been proposed in the literature. Recently, thanks to the high performance of smartphones’ cameras, marker-less and marker-based computer vision approaches have been investigated. In a previous paper, we proposed a technique for indoor localization and navigation using both Bluetooth low energy (BLE) and a 2D visual marker system deployed into the fl oor. In this paper, we presented a qualitative performance evaluation of three 2D visual markers, Vuforia, ArUco marker, and AprilTag, which are suitable for real-time applications. Our analysis focused on specifi c case study of visual markers placed onto the tiles, to improve the efficiency of our indoor localization and navigation approach by choosing the best visual marker system.

  1. Autostereoscopic 3D visualization and image processing system for neurosurgery.

    Science.gov (United States)

    Meyer, Tobias; Kuß, Julia; Uhlemann, Falk; Wagner, Stefan; Kirsch, Matthias; Sobottka, Stephan B; Steinmeier, Ralf; Schackert, Gabriele; Morgenstern, Ute

    2013-06-01

    A demonstrator system for planning neurosurgical procedures was developed based on commercial hardware and software. The system combines an easy-to-use environment for surgical planning with high-end visualization and the opportunity to analyze data sets for research purposes. The demonstrator system is based on the software AMIRA. Specific algorithms for segmentation, elastic registration, and visualization have been implemented and adapted to the clinical workflow. Modules from AMIRA and the image processing library Insight Segmentation and Registration Toolkit (ITK) can be combined to solve various image processing tasks. Customized modules tailored to specific clinical problems can easily be implemented using the AMIRA application programming interface and a self-developed framework for ITK filters. Visualization is done via autostereoscopic displays, which provide a 3D impression without viewing aids. A Spaceball device allows a comfortable, intuitive way of navigation in the data sets. Via an interface to a neurosurgical navigation system, the demonstrator system can be used intraoperatively. The precision, applicability, and benefit of the demonstrator system for planning of neurosurgical interventions and for neurosurgical research were successfully evaluated by neurosurgeons using phantom and patient data sets.

  2. Linear and Nonlinear Systems Analysis of the Visual System: Why does it seem so linear?

    Science.gov (United States)

    Shapley, Robert

    2009-01-01

    Linear and nonlinear systems analysis are tools that can be used to study communication systems like the visual system. The first step of systems analysis often is to test whether or not the system is linear. Retinal pathways are surprisingly linear, and some neurons in the visual cortex also emulate linear sensory transducers. We conclude that the retinal linearity depends on specialized ribbon synapses while cortical linearity is the result of balanced excitatory and inhibitory synaptic interactions. PMID:18940193

  3. Kv1 channels and neural processing in vestibular calyx afferents

    Directory of Open Access Journals (Sweden)

    Frances L Meredith

    2015-06-01

    Full Text Available Potassium-selective ion channels are important for accurate transmission of signals from auditory and vestibular sensory end organs to their targets in the central nervous system. During different gravity conditions, astronauts experience altered input signals from the peripheral vestibular system resulting in sensorimotor dysfunction. Adaptation to altered sensory input occurs, but it is not explicitly known whether this involves synaptic modifications within the vestibular epithelia. Future investigations of such potential plasticity require a better understanding of the electrophysiological mechanisms underlying the known heterogeneity of afferent discharge under normal conditions. This study advances this understanding by examining the role of the Kv1 potassium channel family in mediating action potentials in specialized vestibular afferent calyx endings in the gerbil crista and utricle. Pharmacological agents selective for different sub-types of Kv1 channels were tested on membrane responses in whole cell recordings in the crista. Kv1 channels sensitive to α-dendrotoxin and dendrotoxin-K were found to prevail in the central regions, whereas K+ channels sensitive to margatoxin, which blocks Kv1.3 and 1.6 channels, were more prominent in peripheral regions. Margatoxin-sensitive currents showed voltage-dependent inactivation. Dendrotoxin-sensitive currents showed no inactivation and dampened excitability in calyces in central neuroepithelial regions. The differential distribution of Kv1 potassium channels in vestibular afferents supports their importance in accurately relaying gravitational and head movement signals through specialized lines to the central nervous system. Pharmacological modulation of specific groups of K+ channels could help alleviate vestibular dysfunction on earth and in space.

  4. A dual physiological character for cerebral mechanisms of sexuality and cognition: common somatic peripheral afferents.

    Science.gov (United States)

    Motofei, Ion G

    2011-11-01

    The dual theory of sexuality is a work in progress that tries to put together all the significant physiological aspects described on this subject, the most recent published article discussing about the hormonal and pheromonal neuromodulation of somatic peripheral afferents. But sexuality and cognition shares common somatic peripheral afferents, so that a good understanding of sexual mechanisms supposes also a good knowledge of the essential psychological mechanisms/neuromodulators. Current psychological approaches could be limited to two general tendencies. Some authors consider that cerebral neuronal connexions generate a unitary network substrate that - increasing in its complexity - becomes compatible with our complex mental function. Others suggest that such a complex cerebral function correspond actually to a system based on subsystems, represented by distinct neuronal units (not necessarily complexes) that interact each other. Starting from basic somatic/sexual neurophysiological elements and general accepted psychological aspects, the discussion gave sense to the last point of view, namely that genesis of a new function is the result of cooperation between distinct structural and functional units. Contrary to the classical concepts, this paper sows the fact that mental perception corresponds actually (in term of touch/tangibility) to the internal representation of an external object while sensations realize an internal representation of the external characteristics of environmental object. As a conclusion, sexuality and cognition are two distinct autonomic/dual functions, interrelated at both cerebral and peripheral level. Peripheral interference implies intervention of some specific (mental and sexual) neuromodulators, making external information act as internal mental or internal sexual stimuli. Central cerebral interferences are also clinically and pharmacologically documented, specific neuromodulators being taken into account. Supplementary studies would

  5. Are Visual Peripheries Forever Young?

    Directory of Open Access Journals (Sweden)

    Kalina Burnat

    2015-01-01

    Full Text Available The paper presents a concept of lifelong plasticity of peripheral vision. Central vision processing is accepted as critical and irreplaceable for normal perception in humans. While peripheral processing chiefly carries information about motion stimuli features and redirects foveal attention to new objects, it can also take over functions typical for central vision. Here I review the data showing the plasticity of peripheral vision found in functional, developmental, and comparative studies. Even though it is well established that afferent projections from central and peripheral retinal regions are not established simultaneously during early postnatal life, central vision is commonly used as a general model of development of the visual system. Based on clinical studies and visually deprived animal models, I describe how central and peripheral visual field representations separately rely on early visual experience. Peripheral visual processing (motion is more affected by binocular visual deprivation than central visual processing (spatial resolution. In addition, our own experimental findings show the possible recruitment of coarse peripheral vision for fine spatial analysis. Accordingly, I hypothesize that the balance between central and peripheral visual processing, established in the course of development, is susceptible to plastic adaptations during the entire life span, with peripheral vision capable of taking over central processing.

  6. The unsilent majority-TRPV1 drives "spontaneous" transmission of unmyelinated primary afferents within cardiorespiratory NTS.

    Science.gov (United States)

    Andresen, Michael C; Hofmann, Mackenzie E; Fawley, Jessica A

    2012-12-15

    Cranial primary afferent sensory neurons figure importantly in homeostatic control of visceral organ systems. Of the two broad classes of visceral afferents, the role of unmyelinated or C-type class remains poorly understood. This review contrasts key aspects of peripheral discharge properties of C-fiber afferents and their glutamate transmission mechanisms within the solitary tract nucleus (NTS). During normal prevailing conditions, most information arrives at the NTS through myelinated A-type nerves. However, most of visceral afferent axons (75-90%) in NTS are unmyelinated, C-type axons. Centrally, C-type solitary tract (ST) afferent terminals have presynaptic transient receptor potential vanilloid type 1 (TRPV1) receptors. Capsaicin activation of TRPV1 blocks phasic or synchronous release of glutamate but facilitates release of glutamate from a separate pool of vesicles. This TRPV1-operated pool of vesicles is active at normal temperatures and is responsible for actively driving a 10-fold higher release of glutamate at TRPV1 compared with TRPV1- terminals even in the absence of afferent action potentials. This novel TRPV1 mechanism is responsible for an additional asynchronous release of glutamate that is not present in myelinated terminals. The NTS is rich with presynaptic G protein-coupled receptors, and the implications of TRPV1-operated glutamate offer unique targets for signaling in C-type sensory afferent terminals from neuropeptides, inflammatory mediators, lipid metabolites, cytokines, and cannabinoids. From a homeostatic view, this combination could have broad implications for integration in chronic pathological disturbances in which the numeric dominance of C-type endings and TRPV1 would broadly disturb multisystem control mechanisms.

  7. Big Data Visual Analytics for Exploratory Earth System Simulation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Steed, Chad A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ricciuto, Daniel M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shipman, Galen M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, Brian E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Thornton, Peter E. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wang, Dali [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shi, Xiaoying [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Williams, Dean N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2013-12-01

    Rapid increases in high performance computing are feeding the development of larger and more complex data sets in climate research, which sets the stage for so-called big data analysis challenges. However, conventional climate analysis techniques are inadequate in dealing with the complexities of today s data. In this paper, we describe and demonstrate a visual analytics system, called the Exploratory Data analysis ENvironment (EDEN), with specific application to the analysis of complex earth system simulation data sets. EDEN represents the type of interactive visual analysis tools that are necessary to transform data into insight, thereby improving critical comprehension of earth system processes. In addition to providing an overview of EDEN, we describe real-world studies using both point ensembles and global Community Land Model Version 4 (CLM4) simulations.

  8. An Indoor Navigation System for the Visually Impaired

    Directory of Open Access Journals (Sweden)

    Luis A. Guerrero

    2012-06-01

    Full Text Available Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user’s trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  9. An indoor navigation system for the visually impaired.

    Science.gov (United States)

    Guerrero, Luis A; Vasquez, Francisco; Ochoa, Sergio F

    2012-01-01

    Navigation in indoor environments is highly challenging for the severely visually impaired, particularly in spaces visited for the first time. Several solutions have been proposed to deal with this challenge. Although some of them have shown to be useful in real scenarios, they involve an important deployment effort or use artifacts that are not natural for blind users. This paper presents an indoor navigation system that was designed taking into consideration usability as the quality requirement to be maximized. This solution enables one to identify the position of a person and calculates the velocity and direction of his movements. Using this information, the system determines the user's trajectory, locates possible obstacles in that route, and offers navigation information to the user. The solution has been evaluated using two experimental scenarios. Although the results are still not enough to provide strong conclusions, they indicate that the system is suitable to guide visually impaired people through an unknown built environment.

  10. A visual representation system for the scheduling and management of projects

    NARCIS (Netherlands)

    Pollalis, S.N.

    1992-01-01

    A VISUAL SCHEDULING AND MANAGEMENT SYSTEM (VSMS) This work proposes a new system for the visual representation of projects that displays the quantities of work, resources and cost. This new system, called Visual Scheduling and Management System, has a built-in hierarchical system to provide differen

  11. A visual representation system for the scheduling and management of projects

    NARCIS (Netherlands)

    Pollalis, S.N.

    1992-01-01

    A VISUAL SCHEDULING AND MANAGEMENT SYSTEM (VSMS) This work proposes a new system for the visual representation of projects that displays the quantities of work, resources and cost. This new system, called Visual Scheduling and Management System, has a built-in hierarchical system to provide differen

  12. A visual representation system for the scheduling and management of projects

    NARCIS (Netherlands)

    Pollalis, S.N.

    1992-01-01

    A VISUAL SCHEDULING AND MANAGEMENT SYSTEM (VSMS) This work proposes a new system for the visual representation of projects that displays the quantities of work, resources and cost. This new system, called Visual Scheduling and Management System, has a built-in hierarchical system to provide

  13. Retinal lesions induce fast intrinsic cortical plasticity in adult mouse visual system.

    Science.gov (United States)

    Smolders, Katrien; Vreysen, Samme; Laramée, Marie-Eve; Cuyvers, Annemie; Hu, Tjing-Tjing; Van Brussel, Leen; Eysel, Ulf T; Nys, Julie; Arckens, Lutgarde

    2016-09-01

    Neuronal activity plays an important role in the development and structural-functional maintenance of the brain as well as in its life-long plastic response to changes in sensory stimulation. We characterized the impact of unilateral 15° laser lesions in the temporal lower visual field of the retina, on visually driven neuronal activity in the afferent visual pathway of adult mice using in situ hybridization for the activity reporter gene zif268. In the first days post-lesion, we detected a discrete zone of reduced zif268 expression in the contralateral hemisphere, spanning the border between the monocular segment of the primary visual cortex (V1) with extrastriate visual area V2M. We could not detect a clear lesion projection zone (LPZ) in areas lateral to V1 whereas medial to V2M, agranular and granular retrosplenial cortex showed decreased zif268 levels over their full extent. All affected areas displayed a return to normal zif268 levels, and this was faster in higher order visual areas than in V1. The lesion did, however, induce a permanent LPZ in the retinorecipient layers of the superior colliculus. We identified a retinotopy-based intrinsic capacity of adult mouse visual cortex to recover from restricted vision loss, with recovery speed reflecting the areal cortical magnification factor. Our observations predict incomplete visual field representations for areas lateral to V1 vs. lack of retinotopic organization for areas medial to V2M. The validation of this mouse model paves the way for future interrogations of cortical region- and cell-type-specific contributions to functional recovery, up to microcircuit level.

  14. Functional electrical stimulation post-spinal cord injury improves locomotion and increases afferent input into the central nervous system in rats.

    Science.gov (United States)

    Beaumont, Eric; Guevara, Edgar; Dubeau, Simon; Lesage, Frederic; Nagai, Mary; Popovic, Milos

    2014-01-01

    Functional electrical stimulation (FES) has been found to be effective in restoring voluntary functions after spinal cord injury (SCI) and stroke. However, the central nervous system (CNS) changes that occur in as a result of this therapy are largely unknown. To examine the effects of FES on the restoration of voluntary locomotor function of the CNS in a SCI rat model. SCI rats were instrumented with chronic FES electrodes in the hindlimb muscles and were divided into two groups: (a) FES therapy and (b) sedentary. At day 7 post-SCI, the animals were assessed for locomotion performance by using a Basso, Beattie and Bresnahan (BBB) scale. They were then anesthetized for a terminal in vivo experiment. The lumbar spinal cord and somatosensory cortex were exposed and the instrumented muscles were stimulated electrically. Associated neurovascular responses in the CNS were recorded with an intrinsic optical imaging system. FES greatly improved locomotion recovery by day 7 post-SCI, as measured by BBB scores (P spinal cord and somatosensory cortex when the muscles were stimulated between 1 and 3 motor threshold (MT). Hind limb rehabilitation with FES is an effective strategy to improve locomotion during the acute phase post-SCI. The results of this study indicate that after FES, the CNS preserves/acquires the capacity to respond to peripheral electrical stimulation.

  15. A web-based 3D geological information visualization system

    Science.gov (United States)

    Song, Renbo; Jiang, Nan

    2013-03-01

    Construction of 3D geological visualization system has attracted much more concern in GIS, computer modeling, simulation and visualization fields. It not only can effectively help geological interpretation and analysis work, but also can it can help leveling up geosciences professional education. In this paper, an applet-based method was introduced for developing a web-based 3D geological information visualization system. The main aims of this paper are to explore a rapid and low-cost development method for constructing a web-based 3D geological system. First, the borehole data stored in Excel spreadsheets was extracted and then stored in SQLSERVER database of a web server. Second, the JDBC data access component was utilized for providing the capability of access the database. Third, the user interface was implemented with applet component embedded in JSP page and the 3D viewing and querying functions were implemented with PickCanvas of Java3D. Last, the borehole data acquired from geological survey were used for test the system, and the test results has shown that related methods of this paper have a certain application values.

  16. Environmental information system for visualizing environmental impact assessment information.

    Science.gov (United States)

    Cserny, Angelika; Kovács, Zsófia; Domokos, Endre; Rédey, Akos

    2009-01-01

    The Institute of Environmental Engineering at the University of Pannonia has undertaken the challenge to develop an online environmental information system. This system is able to receive and process the collected environmental data via Internet. The authors have attached importance to the presentation of the data and have included other comprehensible information for laymen as well in order to work out visualisation techniques that are expressive and attract attention for environmental questions through the developed information system. The ways of visualizing physical and chemical parameters of surface water and the effects of motorway construction were examined.

  17. An Avatar-Based Italian Sign Language Visualization System

    Science.gov (United States)

    Falletto, Andrea; Prinetto, Paolo; Tiotto, Gabriele

    In this paper, we present an experimental system that supports the translation from Italian to Italian Sign Language (ISL) of the deaf and its visualization through a virtual character. Our objective is to develop a complete platform useful for any application and reusable on several platforms including Web, Digital Television and offline text translation. The system relies on a database that stores both a corpus of Italian words and words coded in the ISL notation system. An interface for the insertion of data is implemented, that allows future extensions and integrations.

  18. Advanced 3D Sensing and Visualization System for Unattended Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, J.J.; Little, C.Q.; Nelson, C.L.

    1999-01-01

    The purpose of this project was to create a reliable, 3D sensing and visualization system for unattended monitoring. The system provides benefits for several of Sandia's initiatives including nonproliferation, treaty verification, national security and critical infrastructure surety. The robust qualities of the system make it suitable for both interior and exterior monitoring applications. The 3D sensing system combines two existing sensor technologies in a new way to continuously maintain accurate 3D models of both static and dynamic components of monitored areas (e.g., portions of buildings, roads, and secured perimeters in addition to real-time estimates of the shape, location, and motion of humans and moving objects). A key strength of this system is the ability to monitor simultaneous activities on a continuous basis, such as several humans working independently within a controlled workspace, while also detecting unauthorized entry into the workspace. Data from the sensing system is used to identi~ activities or conditions that can signi~ potential surety (safety, security, and reliability) threats. The system could alert a security operator of potential threats or could be used to cue other detection, inspection or warning systems. An interactive, Web-based, 3D visualization capability was also developed using the Virtual Reality Modeling Language (VRML). The intex%ace allows remote, interactive inspection of a monitored area (via the Internet or Satellite Links) using a 3D computer model of the area that is rendered from actual sensor data.

  19. Intelligent Data Visualization for Cross-Checking Spacecraft System Diagnosis

    Science.gov (United States)

    Ong, James C.; Remolina, Emilio; Breeden, David; Stroozas, Brett A.; Mohammed, John L.

    2012-01-01

    Any reasoning system is fallible, so crew members and flight controllers must be able to cross-check automated diagnoses of spacecraft or habitat problems by considering alternate diagnoses and analyzing related evidence. Cross-checking improves diagnostic accuracy because people can apply information processing heuristics, pattern recognition techniques, and reasoning methods that the automated diagnostic system may not possess. Over time, cross-checking also enables crew members to become comfortable with how the diagnostic reasoning system performs, so the system can earn the crew s trust. We developed intelligent data visualization software that helps users cross-check automated diagnoses of system faults more effectively. The user interface displays scrollable arrays of timelines and time-series graphs, which are tightly integrated with an interactive, color-coded system schematic to show important spatial-temporal data patterns. Signal processing and rule-based diagnostic reasoning automatically identify alternate hypotheses and data patterns that support or rebut the original and alternate diagnoses. A color-coded matrix display summarizes the supporting or rebutting evidence for each diagnosis, and a drill-down capability enables crew members to quickly view graphs and timelines of the underlying data. This system demonstrates that modest amounts of diagnostic reasoning, combined with interactive, information-dense data visualizations, can accelerate system diagnosis and cross-checking.

  20. Pain processing by spinal microcircuits: afferent combinatorics.

    Science.gov (United States)

    Prescott, Steven A; Ratté, Stéphanie

    2012-08-01

    Pain, itch, heat, cold, and touch represent different percepts arising from somatosensory input. How stimuli give rise to these percepts has been debated for over a century. Recent work supports the view that primary afferents are highly specialized to transduce and encode specific stimulus modalities. However, cross-modal interactions (e.g. inhibition or exacerbation of pain by touch) support convergence rather than specificity in central circuits. We outline how peripheral specialization together with central convergence could enable spinal microcircuits to combine inputs from distinctly specialized, co-activated afferents and to modulate the output signals thus formed through computations like normalization. These issues will be discussed alongside recent advances in our understanding of microcircuitry in the superficial dorsal horn.

  1. Smart Grid Wide-Area Transmission System Visualization

    Directory of Open Access Journals (Sweden)

    Thomas J. Overbye

    2015-12-01

    Full Text Available The installation of vast quantities of additional new sensing and communication equipment, in conjunction with building the computing infrastructure to store and manage data gathered by this equipment, has been the first step in the creation of what is generically referred to as the “smart grid” for the electric transmission system. With this enormous capital investment in equipment having been made, attention is now focused on developing methods to analyze and visualize this large data set. The most direct use of this large set of new data will be in data visualization. This paper presents a survey of some visualization techniques that have been deployed by the electric power industry for visualizing data over the past several years. These techniques include pie charts, animation, contouring, time-varying graphs, geographic-based displays, image blending, and data aggregation techniques. The paper then emphasizes a newer concept of using word-sized graphics called sparklines as an extremely effective method of showing large amounts of time-varying data.

  2. Designing visual displays and system models for safe reactor operations

    Energy Technology Data Exchange (ETDEWEB)

    Brown-VanHoozer, S.A.

    1995-12-31

    The material presented in this paper is based on two studies involving the design of visual displays and the user`s prospective model of a system. The studies involve a methodology known as Neuro-Linguistic Programming and its use in expanding design choices from the operator`s perspective image. The contents of this paper focuses on the studies and how they are applicable to the safety of operating reactors.

  3. Dynamically multilayered visual system of the multifractal fly.

    Science.gov (United States)

    Baptista, M S; Grebogi, Celso; Köberle, Roland

    2006-10-27

    We dynamically analyze our experimental results on the motion sensitive spiking H1 neuron of the fly's visual system. We find that the fly uses an alphabet composed of a few letters to encode the information contained in the stimulus. The alphabet dynamics is multifractal both with and without stimulus, though the multifractality increases with the stimulus entropy. This is in sharp contrast to models generating independent spike intervals, whose dynamics is monofractal.

  4. Meningeal afferent signaling and the pathophysiology of migraine.

    Science.gov (United States)

    Burgos-Vega, Carolina; Moy, Jamie; Dussor, Gregory

    2015-01-01

    Migraine is the most common neurological disorder. Attacks are complex and consist of multiple phases but are most commonly characterized by intense, unilateral, throbbing headache. The pathophysiology contributing to migraine is poorly understood and the disorder is not well managed with currently available therapeutics, often rendering patients disabled during attacks. The mechanisms most likely to contribute to the pain phase of migraine require activation of trigeminal afferent signaling from the cranial meninges and subsequent relay of nociceptive information into the central nervous system in a region of the dorsal brainstem known as the trigeminal nucleus caudalis. Events leading to activation of meningeal afferents are unclear, but nerve endings within this tissue are mechanosensitive and also express a variety of ion channels including acid-sensing ion channels and transient receptor-potential channels. These properties may provide clues into the pathophysiology of migraine by suggesting that decreased extracellular pH and environmental irritant exposure in the meninges contributes to headache. Neuroplasticity is also likely to play a role in migraine given that attacks are triggered by routine events that are typically nonnoxious in healthy patients and clear evidence of sensitization occurs during an attack. Where and how plasticity develops is also not clear but may include events directly on the afferents and/or within the TNC. Among the mediators potentially contributing to plasticity, calcitonin gene-related peptide has received the most attention within the migraine field but other mechanisms may also contribute. Ultimately, greater understanding of the molecules and mechanisms contributing to migraine will undoubtedly lead to better therapeutics and relief for the large number of patients across the globe who suffer from this highly disabling neurological disorder.

  5. A Visual-aided Inertial Navigation and Mapping System

    Directory of Open Access Journals (Sweden)

    Rodrigo Munguía

    2016-05-01

    Full Text Available State estimation is a fundamental necessity for any application involving autonomous robots. This paper describes a visual-aided inertial navigation and mapping system for application to autonomous robots. The system, which relies on Kalman filtering, is designed to fuse the measurements obtained from a monocular camera, an inertial measurement unit (IMU and a position sensor (GPS. The estimated state consists of the full state of the vehicle: the position, orientation, their first derivatives and the parameter errors of the inertial sensors (i.e., the bias of gyroscopes and accelerometers. The system also provides the spatial locations of the visual features observed by the camera. The proposed scheme was designed by considering the limited resources commonly available in small mobile robots, while it is intended to be applied to cluttered environments in order to perform fully vision-based navigation in periods where the position sensor is not available. Moreover, the estimated map of visual features would be suitable for multiple tasks: i terrain analysis; ii three dimensional (3D scene reconstruction; iii localization, detection or perception of obstacles and generating trajectories to navigate around these obstacles; and iv autonomous exploration. In this work, simulations and experiments with real data are presented in order to validate and demonstrate the performance of the proposal.

  6. Visual Simulation of Microalgae Growth in Bioregenerative Life Support System

    Science.gov (United States)

    Zhao, Ming

    Bioregenerative life support system is one of the key technologies for future human deep space exploration and long-term space missions. BLSS use biological system as its core unit in combination with other physical and chemical equipments, under the proper control and manipulation by crew to complete a specific task to support life. Food production, waste treatment, oxygen and water regeneration are all conducted by higher plants or microalgae in BLSS, which is the most import characteristic different from other kinds of life support systems. Microalgae is light autotrophic micro-organisms, light undoubtedly is the most import factor which limits its growth and reproduction. Increasing or decreasing the light intensity changes the growth rate of microalgae, and then regulates the concentration of oxygen and carbon dioxide in the system. In this paper, based on the mathematical model of microalgae which grew under the different light intensity, three-dimensional visualization model was built and realized through using 3ds max, Virtools and some other three dimensional software, in order to display its change and impacting on oxygen and carbon dioxide intuitively. We changed its model structure and parameters, such as establishing closed-loop control system, light intensity, temperature and Nutrient fluid’s velocity and so on, carried out computer virtual simulation, and observed dynamic change of system with the aim of providing visualization support for system research.

  7. Rapid Global Calibration Technology for Hybrid Visual Inspection System.

    Science.gov (United States)

    Liu, Tao; Yin, Shibin; Guo, Yin; Zhu, Jigui

    2017-06-19

    Vision-based methods for product quality inspection are playing an increasingly important role in modern industries for their good performance and high efficiency. A hybrid visual inspection system, which consists of an industrial robot with a flexible sensor and several stationary sensors, has been widely applied in mass production, especially in automobile manufacturing. In this paper, a rapid global calibration method for the hybrid visual inspection system is proposed. Global calibration of a flexible sensor is performed first based on the robot kinematic. Then, with the aid of the calibrated flexible sensor, stationary sensors are calibrated globally one by one based on homography. Only a standard sphere and an auxiliary target with a 2D planar pattern are applied during the system global calibration, and the calibration process can be easily re-performed during the system's periodical maintenance. An error compensation method is proposed for the hybrid inspection system, and the final accuracy of the hybrid system is evaluated with the deviation and correlation coefficient between the measured results of the hybrid system and Coordinate Measuring Machine (CMM). An accuracy verification experiment shows that deviation of over 95% of featured points are less than ±0.3 mm, and the correlation coefficients of over 85% of points are larger than 0.7.

  8. Windows into the Visual Brain: New Discoveries about the Visual System, Its Functions, and Implications for Practitioners

    Science.gov (United States)

    Jan, James E.; Heaven, Roberta K. B.; Matsuba, Carey; Langley, M. Beth; Roman-Lantzy, Christine; Anthony, Tanni L

    2013-01-01

    Introduction: In recent years, major progress has been made in understanding the human visual system because of new investigative techniques. These developments often contradict older concepts about visual function. Methods: A detailed literature search and interprofessional discussions. Results: Recent innovative neurological tests are described…

  9. Windows into the Visual Brain: New Discoveries about the Visual System, Its Functions, and Implications for Practitioners

    Science.gov (United States)

    Jan, James E.; Heaven, Roberta K. B.; Matsuba, Carey; Langley, M. Beth; Roman-Lantzy, Christine; Anthony, Tanni L

    2013-01-01

    Introduction: In recent years, major progress has been made in understanding the human visual system because of new investigative techniques. These developments often contradict older concepts about visual function. Methods: A detailed literature search and interprofessional discussions. Results: Recent innovative neurological tests are described…

  10. Visual Peoplemeter: A Vision-based Television Audience Measurement System

    Directory of Open Access Journals (Sweden)

    SKELIN, A. K.

    2014-11-01

    Full Text Available Visual peoplemeter is a vision-based measurement system that objectively evaluates the attentive behavior for TV audience rating, thus offering solution to some of drawbacks of current manual logging peoplemeters. In this paper, some limitations of current audience measurement system are reviewed and a novel vision-based system aiming at passive metering of viewers is prototyped. The system uses camera mounted on a television as a sensing modality and applies advanced computer vision algorithms to detect and track a person, and to recognize attentional states. Feasibility of the system is evaluated on a secondary dataset. The results show that the proposed system can analyze viewer's attentive behavior, therefore enabling passive estimates of relevant audience measurement categories.

  11. Visual Cortex Plasticity Following Peripheral Damage To The Visual System: fMRI Evidence.

    Science.gov (United States)

    Lemos, João; Pereira, Daniela; Castelo-Branco, Miguel

    2016-10-01

    Over the last two decades, functional magnetic resonance imaging (fMRI) has become a powerful research method to investigate cortical visual plasticity. Abnormal fMRI response patterns have been occasionally detected in the visually deprived cortex of patients with bilateral retinal diseases. Controversy remains whether these observations indicate structural reorganization of the visual cortex or unmasking of previously silent cortico-cortical connections. In optic nerve diseases, there is weak evidence showing that early visual cortex seems to lack reorganization, while higher-order visual areas undergo plastic changes which may contribute to optimise visual function. There is however accumulating imaging evidence demonstrating trans-synaptic degeneration of the visual cortex in patients with disease of the anterior visual pathways. This may preclude the use of restorative treatments in these patients. Here, we review and update the body of fMRI evidence on visual cortical plasticity.

  12. Functional analysis of ultra high information rates conveyed by rat vibrissal primary afferents

    NARCIS (Netherlands)

    A.M. Chagas (André); L. Theis (Lucas); B. Sengupta (Biswa); M.C. Stüttgen (Maik); M. Bethge (Matthias); C. Schwarz (Cornelius)

    2013-01-01

    textabstractSensory receptors determine the type and the quantity of information available for perception. Here, we quantified and characterized the information transferred by primary afferents in the rat whisker system using neural system identification. Quantification of "how much" information is

  13. Rapid Global Calibration Technology for Hybrid Visual Inspection System

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-06-01

    Full Text Available Vision-based methods for product quality inspection are playing an increasingly important role in modern industries for their good performance and high efficiency. A hybrid visual inspection system, which consists of an industrial robot with a flexible sensor and several stationary sensors, has been widely applied in mass production, especially in automobile manufacturing. In this paper, a rapid global calibration method for the hybrid visual inspection system is proposed. Global calibration of a flexible sensor is performed first based on the robot kinematic. Then, with the aid of the calibrated flexible sensor, stationary sensors are calibrated globally one by one based on homography. Only a standard sphere and an auxiliary target with a 2D planar pattern are applied during the system global calibration, and the calibration process can be easily re-performed during the system’s periodical maintenance. An error compensation method is proposed for the hybrid inspection system, and the final accuracy of the hybrid system is evaluated with the deviation and correlation coefficient between the measured results of the hybrid system and Coordinate Measuring Machine (CMM. An accuracy verification experiment shows that deviation of over 95% of featured points are less than ±0.3 mm, and the correlation coefficients of over 85% of points are larger than 0.7.

  14. Individual differences in involvement of the visual object recognition system during visual word recognition.

    Science.gov (United States)

    Laszlo, Sarah; Sacchi, Elizabeth

    2015-01-01

    Individuals with dyslexia often evince reduced activation during reading in left hemisphere (LH) language regions. This can be observed along with increased activation in the right hemisphere (RH), especially in areas associated with object recognition - a pattern referred to as RH compensation. The mechanisms of RH compensation are relatively unclear. We hypothesize that RH compensation occurs when the RH object recognition system is called upon to supplement an underperforming LH visual word form recognition system. We tested this by collecting ERPs while participants with a range of reading abilities viewed words, objects, and word/object ambiguous items (e.g., "SMILE" shaped like a smile). Less experienced readers differentiate words, objects, and ambiguous items less strongly, especially over the RH. We suggest that this lack of differentiation may have negative consequences for dyslexic individuals demonstrating RH compensation.

  15. Dataspace: an automated visualization system for large databases

    Science.gov (United States)

    Petajan, Eric D.; Jean, Yves D.; Lieuwen, Dan; Anupam, Vinod

    1997-04-01

    DataSpace is a multi-platform software system for easily visualizing relational databases using a set of flexible 3D graphics tools. Typically, five attributes are selected for a given visualization session where two of the attributes are used to generate 2D plots and the other three attributes are used to position the 2D plots in a regular 3D lattice. Mouse-based 3D navigation with constraints allows the user to see the 'forest and the trees' without getting 'lost in space'. DataSpace uses the Standard Query Language to allow connection popular database systems. DataSpace also incorporates a variety of additional tools e.g., aggregation, data 'drill down', multidimensional scaling, variable transparency, query by example, and display of graphics from external applications. Labeling of node contents is automatic. 3D strokefonts are used to provide readable yet scalable text in a 3D environment. Since interactive 3D navigation is essential to DataSpace, we have incorporated several methods for adaptively reducing graphical detail without losing information when the host machine is overloaded. DataSpace has been sued to visualized databases containing over 1 million records with interactive performance. In particular, large databases containing stock price information and telecommunications customer profiles have been analyzed using DataSpace.

  16. Learning Visual Representations for Perception-Action Systems

    DEFF Research Database (Denmark)

    Piater, Justus; Jodogne, Sebastien; Detry, Renaud;

    2011-01-01

    We discuss vision as a sensory modality for systems that effect actions in response to perceptions. While the internal representations informed by vision may be arbitrarily complex, we argue that in many cases it is advantageous to link them rather directly to action via learned mappings. These a......We discuss vision as a sensory modality for systems that effect actions in response to perceptions. While the internal representations informed by vision may be arbitrarily complex, we argue that in many cases it is advantageous to link them rather directly to action via learned mappings....... These arguments are illustrated by two examples of our own work. First, our RLVC algorithm performs reinforcement learning directly on the visual input space. To make this very large space manageable, RLVC interleaves the reinforcement learner with a supervised classification algorithm that seeks to split...... perceptual states so as to reduce perceptual aliasing. This results in an adaptive discretization of the perceptual space based on the presence or absence of visual features. Its extension RLJC also handles continuous action spaces. In contrast to the minimalistic visual representations produced by RLVC...

  17. Group Ia afferents contribute to short-latency interlimb reflexes in the human biceps femoris muscle

    DEFF Research Database (Denmark)

    Stevenson, Andrew James Thomas; Kamavuako, Ernest Nlandu; Geertsen, Svend Sparre

    2017-01-01

    and velocity of the iKnee rotations. Methods 11 seated participants (mean age: 25 ± 5 years) performed a voluntary isometric knee extension with the ipsilateral leg and contralateral knee flexion to 10% of maximum voluntary contraction (MVC). A mechanical actuator (MTS-Systems Corporation) imposed i...... amplitudes (4 vs. 8°) at the same 150°/s velocity (p’s > 0.08). Conclusion Because fast conducting group Ia muscle spindle afferents are sensitive to changes in muscle stretch velocity, while group II spindle afferents are sensitive to changes in amplitude (Grey et al., JPhysiol., 2001; Matthews, Trends...... Neurosci., 1991), group Ia velocity sensitive muscle spindle afferents likely contribute to the short-latency crossed spinal reflexes in the cBF muscle following iKnee joint rotations. This supports the findings for the short-latency crossed responses in the human soleus muscle (Stubbs & Mrachacz...

  18. Visual Attention Shift based on Image Segmentation Using Neurodynamic System

    Directory of Open Access Journals (Sweden)

    Lijuan Duan

    2011-01-01

    Full Text Available A method of predicting visual attention shift is proposed based on image segmentation using neurodynamic system in this paper. The input image is mapped to a neural oscillator network. Each oscillator corresponding to a pixel is modeled by means of simplified Wilson-Cowan equations, and is coupled with its 8-nearest neighbors. Then the image is segmented by classifying the oscillation curves of the excitatory groups of all the oscillators. The classifier is constructed based on features of frequency, offset, phase and amplitude of the curves. The visual attention shift between the regions on the image is predicted according to the saliency strength of each region. Referring to the mechanism of winner-take-all competition, the saliency of a region is the aggregation of the dissimilarities between this region and all the other ones. Experimental results on images show the effectiveness of our method.

  19. Research on the Visual Processing System of the Punch Press

    Directory of Open Access Journals (Sweden)

    Sun Xuan

    2016-01-01

    Full Text Available Most of raw materials of small hardware processing for plate scraps, and it’s realized through the manual operation of ordinary punch, which way has the low production efficiency and the high labor intensity. In order to improve the automation level of production, developing and designing of a visual processing system for punch press manipulator which based on the MFC tools of Visual Studio software platform. Through the image acquisition and image processing, get the information about the board to be processed, such as shape, length, the center of gravity position and pose, and providing relevant parameters for positioning gripping and placing into the punch table positioning of the feeding manipulator and automatic programming of punching machine, so as to realize the automatic operation about press feeding and processing.

  20. Design principles of insect and vertebrate visual systems.

    Science.gov (United States)

    Sanes, Joshua R; Zipursky, S Lawrence

    2010-04-15

    A century ago, Cajal noted striking similarities between the neural circuits that underlie vision in vertebrates and flies. Over the past few decades, structural and functional studies have provided strong support for Cajal's view. In parallel, genetic studies have revealed some common molecular mechanisms controlling development of vertebrate and fly visual systems and suggested that they share a common evolutionary origin. Here, we review these shared features, focusing on the first several layers-retina, optic tectum (superior colliculus), and lateral geniculate nucleus in vertebrates; and retina, lamina, and medulla in fly. We argue that vertebrate and fly visual circuits utilize common design principles and that taking advantage of this phylogenetic conservation will speed progress in elucidating both functional strategies and developmental mechanisms, as has already occurred in other areas of neurobiology ranging from electrical signaling and synaptic plasticity to neurogenesis and axon guidance.

  1. A complex biological system: the fly's visual module.

    Science.gov (United States)

    Baptista, Murilo S; de Almeida, Lirio O B; Slaets, Jan F W; Köberle, Roland; Grebogi, Celso

    2008-02-13

    Is the characterization of biological systems as complex systems in the mathematical sense a fruitful assertion? In this paper we argue in the affirmative, although obviously we do not attempt to confront all the issues raised by this question. We use the fly's visual system as an example and analyse our experimental results of one particular neuron in the fly's visual system from this point of view. We find that the motion-sensitive 'H1' neuron, which converts incoming signals into a sequence of identical pulses or 'spikes', encodes the information contained in the stimulus into an alphabet composed of a few letters. This encoding occurs on multilayered sets, one of the features attributed to complex systems. The conversion of intervals between consecutive occurrences of spikes into an alphabet requires us to construct a generating partition. This entails a one-to-one correspondence between sequences of spike intervals and words written in the alphabet. The alphabet dynamics is multifractal both with and without stimulus, though the multifractality increases with the stimulus entropy. This is in sharp contrast to models generating independent spike intervals, such as models using Poisson statistics, whose dynamics is monofractal. We embed the support of the probability measure, which describes the distribution of words written in this alphabet, in a two-dimensional space, whose topology can be reproduced by an M-shaped map. This map has positive Lyapunov exponents, indicating a chaotic-like encoding.

  2. An indoor navigation system to support the visually impaired.

    Science.gov (United States)

    Riehle, T H; Lichter, P; Giudice, N A

    2008-01-01

    Indoor navigation technology is needed to support seamless mobility for the visually impaired. A small portable personal navigation device that provides current position, useful contextual wayfinding information about the indoor environment and directions to a destination would greatly improve access and independence for people with low vision. This paper describes the construction of such a device which utilizes a commercial Ultra-Wideband (UWB) asset tracking system to support real-time location and navigation information. Human trials were conducted to assess the efficacy of the system by comparing target-finding performance between blindfolded subjects using the navigation system for real-time guidance, and blindfolded subjects who only received speech information about their local surrounds but no route guidance information (similar to that available from a long cane or guide dog). A normal vision control condition was also run. The time and distance traveled was measured in each trial and a point-back test was performed after goal completion to assess cognitive map development. Statistically significant differences were observed between the three conditions in time and distance traveled; with the navigation system and the visual condition yielding the best results, and the navigation system dramatically outperforming the non-guided condition.

  3. Models of utricular bouton afferents: role of afferent-hair cell connectivity in determining spike train regularity.

    Science.gov (United States)

    Holmes, William R; Huwe, Janice A; Williams, Barbara; Rowe, Michael H; Peterson, Ellengene H

    2017-05-01

    Vestibular bouton afferent terminals in turtle utricle can be categorized into four types depending on their location and terminal arbor structure: lateral extrastriolar (LES), striolar, juxtastriolar, and medial extrastriolar (MES). The terminal arbors of these afferents differ in surface area, total length, collecting area, number of boutons, number of bouton contacts per hair cell, and axon diameter (Huwe JA, Logan CJ, Williams B, Rowe MH, Peterson EH. J Neurophysiol 113: 2420-2433, 2015). To understand how differences in terminal morphology and the resulting hair cell inputs might affect afferent response properties, we modeled representative afferents from each region, using reconstructed bouton afferents. Collecting area and hair cell density were used to estimate hair cell-to-afferent convergence. Nonmorphological features were held constant to isolate effects of afferent structure and connectivity. The models suggest that all four bouton afferent types are electrotonically compact and that excitatory postsynaptic potentials are two to four times larger in MES afferents than in other afferents, making MES afferents more responsive to low input levels. The models also predict that MES and LES terminal structures permit higher spontaneous firing rates than those in striola and juxtastriola. We found that differences in spike train regularity are not a consequence of differences in peripheral terminal structure, per se, but that a higher proportion of multiple contacts between afferents and individual hair cells increases afferent firing irregularity. The prediction that afferents having primarily one bouton contact per hair cell will fire more regularly than afferents making multiple bouton contacts per hair cell has implications for spike train regularity in dimorphic and calyx afferents.NEW & NOTEWORTHY Bouton afferents in different regions of turtle utricle have very different morphologies and afferent-hair cell connectivities. Highly detailed computational

  4. Alterations of the visual pathways in congenital blindness

    DEFF Research Database (Denmark)

    Ptito, Maurice; Schneider, Fabien C G; Paulson, Olaf B

    2008-01-01

    We used whole brain MRI voxel-based morphometry (VBM) to study the anatomical organization of the visual system in congenitally blind (CB) adults. Eleven CB without a history of visual perception were compared with 21 age- and sex-matched normal-sighted controls (NS). CB showed significant atrophy...... of the geniculo-striate system, encompassing the optic nerves, the optic chiasm, the optic radiations and the primary visual cortex (BA17). The volume decrease in BA17 reached 25% in both hemispheres. The pulvinar and its projections to the associative visual areas were also dramatically altered, BA18....../19 and the middle temporal cortex (MT) showing volume reductions of up to 20%. Additional significant white matter alterations were observed in the inferior longitudinal tract and in the posterior part of the corpus callosum, which links the visual areas of both hemispheres. Our data indicate that the afferent...

  5. Peptide and lipid modulation of glutamatergic afferent synaptic transmission in the solitary tract nucleus

    Directory of Open Access Journals (Sweden)

    Michael C. Andresen

    2013-01-01

    Full Text Available The brainstem nucleus of the solitary tract (NTS holds the first central neurons in major homeostatic reflex pathways. These homeostatic reflexes regulate and coordinate multiple organ systems from gastrointestinal to cardiopulmonary functions. The core of many of these pathways arise from cranial visceral afferent neurons that enter the brain as the solitary tract (ST with more than two-thirds arising from the gastrointestinal system. About one quarter of ST afferents have myelinated axons but the majority are classed as unmyelinated C-fibers. All ST afferents release the fast neurotransmitter glutamate with remarkably similar, high-probability release characteristics. Second order NTS neurons receive surprisingly limited primary afferent information with one or two individual inputs converging on single second order NTS neurons. A- and C-fiber afferents never mix at NTS second order neurons. Many transmitters modify the basic glutamatergic excitatory postsynaptic current (EPSC often by reducing glutamate release or interrupting terminal depolarization. Thus, a distinguishing feature of ST transmission is presynaptic expression of G-protein coupled receptors for peptides common to peripheral or forebrain (e.g. hypothalamus neuron sources. Presynaptic receptors for angiotensin (AT1, vasopressin (V1a, oxytocin (OT, opioid (MOR, ghrelin (GHSR1 and cholecystokinin (CCK differentially control glutamate release on particular subsets of neurons with most other ST afferents unaffected. Lastly, lipid-like signals are transduced by two key ST presynaptic receptors, the transient receptor potential vanilloid type 1 (TRPV1 and the cannabinoid receptor (CB1 that oppositely control glutamate release. Increasing evidence suggests that peripheral nervous signaling mechanisms are repurposed at central terminals to control excitation and are major sites of signal integration of peripheral and central inputs particularly from the hypothalamus.

  6. Modulation of long-latency afferent inhibition by the amplitude of sensory afferent volley.

    Science.gov (United States)

    Turco, Claudia V; El-Sayes, Jenin; Fassett, Hunter J; Chen, Robert; Nelson, Aimee J

    2017-07-01

    Long-latency afferent inhibition (LAI) is the inhibition of the transcranial magnetic stimulation (TMS) motor-evoked potentials (MEP) by the sensory afferent volley following electrical stimulation of a peripheral nerve. It is unknown how the activation of sensory afferent fibers relates to the magnitude of LAI. This study investigated the relationship between LAI and the sensory nerve action potentials (SNAP) from the median nerve (MN) and the digital nerves (DN) of the second digit. LAI was obtained by delivering nerve stimulation 200 ms before a TMS pulse delivered over the motor cortex. Experiment 1 assessed the magnitude of LAI following stimulation of the contralateral MN or DN using nerve stimulus intensities relative to the maximum SNAP (SNAPmax) of that nerve and two TMS intensities (0.5- and 1-mV MEP). Results indicate that MN LAI is maximal at ~50% SNAPmax, when presumably all sensory afferents are recruited for TMS of 0.5-mV MEP. For DN, LAI appears at ~50% SNAPmax and does not increase with further recruitment of sensory afferents. Experiment 2 investigated the magnitude of LAI following ipsilateral nerve stimulation at intensities relative to SNAPmax Results show minimal LAI evoked by ipsilateral MN and no LAI following ipsilateral DN stimulation. Implications for future studies investigating LAI include adjusting nerve stimulation to 50% SNAPmax to obtain maximal LAI. Additionally, MN LAI can be used as a marker for neurological disease or injury by using a nerve stimulation intensity that can evoke a depth of LAI capable of increasing or decreasing.NEW & NOTEWORTHY This is the first investigation of the relationship between long-latency afferent inhibition (LAI) and the sensory afferent volley. Differences exist between median and digital nerve LAI. For the median nerve, LAI increases until all sensory fibers are presumably recruited. In contrast, digital nerve LAI does not increase with the recruitment of additional sensory fibers but rather is

  7. Research and Implementation of 3D Stereo Visual System for Flight Simulation

    Institute of Scientific and Technical Information of China (English)

    黄安祥; 于恒进; 陈宗基; 李明

    2002-01-01

    In military aircrafl fiight simulation, visual cues require depth sense,stereo sense and large field of view. To satisfy these requirements, we set up a space stereo visual system for flight simulation. This paper discusses the design issues of this visual system, including design principles, system implementations,as well as practical solutions to some key problems.

  8. Primary afferent depolarization of muscle afferents elicited by stimulation of joint afferents in cats with intact neuraxis and during reversible spinalization.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Jiménez, I; Schmidt, R F; Rudomin, P

    1993-11-01

    spinalization. 6. The results obtained suggest that intermediate and high-threshold myelinated fibers in the PAN have the same actions on Ia and Ib fibers as intermediate and high-threshold cutaneous afferents and may therefore be considered as belonging to the same functional system. They further indicate that in anesthetized preparations the pathways mediating the PAD of group I fibers, as well as the pathways mediating the inhibition of the PAD, may be subjected to a descending control that is removed by spinalization.

  9. Information processing in the primate visual system - An integrated systems perspective

    Science.gov (United States)

    Van Essen, David C.; Anderson, Charles H.; Felleman, Daniel J.

    1992-01-01

    The primate visual system contains dozens of distinct areas in the cerebral cortex and several major subcortical structures. These subdivisions are extensively interconnected in a distributed hierarchical network that contains several intertwined processing streams. A number of strategies are used for efficient information processing within this hierarchy. These include linear and nonlinear filtering, passage through information bottlenecks, and coordinated use of multiple types of information. In addition, dynamic regulation of information flow within and between visual areas may provide the computational flexibility needed for the visual system to perform a broad spectrum of tasks accurately and at high resolution.

  10. Scientific Visualization & Modeling for Earth Systems Science Education

    Science.gov (United States)

    Chaudhury, S. Raj; Rodriguez, Waldo J.

    2003-01-01

    Providing research experiences for undergraduate students in Earth Systems Science (ESS) poses several challenges at smaller academic institutions that might lack dedicated resources for this area of study. This paper describes the development of an innovative model that involves students with majors in diverse scientific disciplines in authentic ESS research. In studying global climate change, experts typically use scientific visualization techniques applied to remote sensing data collected by satellites. In particular, many problems related to environmental phenomena can be quantitatively addressed by investigations based on datasets related to the scientific endeavours such as the Earth Radiation Budget Experiment (ERBE). Working with data products stored at NASA's Distributed Active Archive Centers, visualization software specifically designed for students and an advanced, immersive Virtual Reality (VR) environment, students engage in guided research projects during a structured 6-week summer program. Over the 5-year span, this program has afforded the opportunity for students majoring in biology, chemistry, mathematics, computer science, physics, engineering and science education to work collaboratively in teams on research projects that emphasize the use of scientific visualization in studying the environment. Recently, a hands-on component has been added through science student partnerships with school-teachers in data collection and reporting for the GLOBE Program (GLobal Observations to Benefit the Environment).

  11. New data visualization of the LHC Era Monitoring (Lemon) system

    Science.gov (United States)

    Ivan, Fedorko; Veronique, Lefebure; Daniel, Lenkes; Omar, Pera Mira

    2012-12-01

    In the last few years, new requirements have been received for visualization of monitoring data: advanced graphics, flexibility in configuration and decoupling of the presentation layer from the monitoring repository. Lemonweb is the data visualization component of the LHC Era Monitoring (Lemon) system. Lemonweb consists of two subcomponents: a data collector and a web visualization interface. The data collector is a daemon, implemented in Python, responsible for data gathering from the central monitoring repository and storing into time series data structures. Data is stored on disk in Round Robin Database (RRD) files: one file per monitored entity, with set of entity related metrics. Entities may be grouped into a hierarchical structure, called “clusters” and supporting mathematical operations over entities and clusters (e.g. cluster A + cluster B /clusters C - entity XY). Using the configuration information, a cluster definition is evaluated in the collector engine and, at runtime, a sequence of data selects is built, to optimize access to the central monitoring repository. In this article, an overview of the design and architecture as well as highlights of some implemented features will be presented.

  12. Head Worn Display System for Equivalent Visual Operations

    Science.gov (United States)

    Cupero, Frank; Valimont, Brian; Wise, John; Best. Carl; DeMers, Bob

    2009-01-01

    Head-Worn Displays or so-called, near-to-eye displays have potentially significant advantages in terms of cost, overcoming cockpit space constraints, and for the display of spatially-integrated information. However, many technical issues need to be overcome before these technologies can be successfully introduced into commercial aircraft cockpits. The results of three activities are reported. First, the near-to-eye display design, technological, and human factors issues are described and a literature review is presented. Second, the results of a fixed-base piloted simulation, investigating the impact of near to eye displays on both operational and visual performance is reported. Straight-in approaches were flown in simulated visual and instrument conditions while using either a biocular or a monocular display placed on either the dominant or non-dominant eye. The pilot's flight performance, visual acuity, and ability to detect unsafe conditions on the runway were tested. The data generally supports a monocular design with minimal impact due to eye dominance. Finally, a method for head tracker system latency measurement is developed and used to compare two different devices.

  13. Live Interrogation and Visualization of Earth Systems (LIVES)

    Science.gov (United States)

    Nunn, J. A.; Anderson, L. C.

    2007-12-01

    Twenty tablet PCs and associated peripherals acquired through a HP Technology for Teaching grant are being used to redesign two freshman laboratory courses as well as a sophomore geobiology course in Geology and Geophysics at Louisiana State University. The two introductory laboratories serve approximately 750 students per academic year including both majors and non-majors; the geobiology course enrolls about 35 students/year and is required for majors in the department's geology concentration. Limited enrollments and 3 hour labs make it possible to incorporate hands-on visualization, animation, GIS, manipulation of data and images, and access to geological data available online. Goals of the course redesigns include: enhancing visualization of earth materials, physical/chemical/biological processes, and biosphere/geosphere history; strengthening student's ability to acquire, manage, and interpret multifaceted geological information; fostering critical thinking, the scientific method, and earth-system science/perspective in ancient and modern environments (such as coastal erosion and restoration in Louisiana or the Snowball Earth hypothesis); improving student communication skills; and increasing the quantity, quality, and diversity of students pursuing Earth Science careers. IT resources available in the laboratory provide students with sophisticated visualization tools, allowing them to switch between 2-D and 3-D reconstructions more seamlessly, and enabling them to manipulate larger integrated data- sets, thus permitting more time for critical thinking and hypothesis testing. IT resources also enable faculty and students to simultaneously work with simulation software to animate earth processes such as plate motions or groundwater flow and immediately test hypothesis formulated in the data analysis. Finally, tablet PCs make it possible for data gathering and analysis outside a formal classroom. As a result, students will achieve fluency in using visualization

  14. Hair-Cell Versus Afferent Adaptation in the Semicircular Canals

    OpenAIRE

    Rabbitt, R. D.; Boyle, R.; Holstein, G. R.; Highstein, S. M.

    2004-01-01

    The time course and extent of adaptation in semicircular canal hair cells was compared to adaptation in primary afferent neurons for physiological stimuli in vivo to study the origins of the neural code transmitted to the brain. The oyster toadfish, Opsanus tau, was used as the experimental model. Afferent firing-rate adaptation followed a double-exponential time course in response to step cupula displacements. The dominant adaptation time constant varied considerably among afferent fibers an...

  15. Fuel visual inspection system of the RTMIII; Sistema de inspeccion visual de combustible del RTMIII

    Energy Technology Data Exchange (ETDEWEB)

    Delfin L, A.; Castaneda J, G.; Mazon R, R.; Aguilar H, F. [ININ, Km. 36.5 Carretera Mexico-Toluca, Ocoyoacac, 52245 Estado de Mexico (Mexico)]. e-mail: rmr@nuclear.inin.mx

    2007-07-01

    The International Atomic Energy Agency (IAEA) through the RLA/04/18 project, Management of Irradiated Fuel in Research Reactors, it recommended among other that the participant countries (Brazil, Argentina, Chile, Peru and Mexico), develop tools to assure the integrity of the nuclear fuels used in the research reactors. The TRIGA Mark lll reactor (RTMIII) of the ININ, designed and built a system of visual inspection, that it uses a high radiation camera and image digitalisation. The project considers safety conditions of the personnel that carried out the activities of visual inspection, for that which the tool dives in the pool of the RTMIII, being held by an end in the superior part of the aluminium liner of the Reactor like it is shown in the plane No. 1. The primordial unit of the system is the visual equipment that corresponds to a camera of the Hydro-Technologie (HYTEC) VSLT 410N mark, designed to work in atmospheres under the water and/or in places of high risk. The camera has an unit of motorized orientation of stainless steel that can be rotated unboundedly in both senses, with variable speed by means of a control lever from the control unit. Together to this orientation unit is found the camera head, the one which is contained in an unit of motorized inclination of stainless steel that can be rotated azimuthally up to 370 degrees in both senses. The operation conditions of the camera are the following ones, temperature: 0 to 50 C, dose speed: {<=} 50 rad/h, operation depth: {<=} 30 mts, humidity (control unit): {<=} 80%. From the control unit it is derived an external device plug-n-play TV-Usb Aver Media marks whose function is to decode the video signal sent by the control unit and to transmit it to the computer where the image is captured in picture or video that is analyzed later on with any software ad hoc, that in our case we use the Quantikov Image Analyzer program for Windows 98 of the Dr. Lucio C. M. Pinto from Brazil who participates in the RLA

  16. Diurnality, nocturnality, and the evolution of primate visual systems.

    Science.gov (United States)

    Ankel-Simons, F; Rasmussen, D T

    2008-01-01

    Much of the recent research on the evolution of primate visual systems has assumed that a minimum number of shifts have occurred in circadian activity patterns over the course of primate evolution. The evolutionary origins of key higher taxonomic groups have been interpreted by some researchers as a consequence of a rare shift from nocturnality to diurnality (e.g., Anthropoidea) or from diurnality to nocturnality (e.g., Tarsiidae). Interpreting the evolution of primate visual systems with an ecological approach without parsimony constraints suggests that the evolutionary transitions in activity pattern are more common than what would be allowed by parsimony models, and that such transitions are probably less important in the origin of higher level taxa. The analysis of 17 communities of primates distributed widely around the world and through geological time shows that primate communities consistently contain both nocturnal and diurnal forms, regardless of the taxonomic sources of the communities. This suggests that primates in a community will adapt their circadian pattern to fill empty diurnal or nocturnal niches. Several evolutionary transitions from one pattern to the other within narrow taxonomic groups are solidly documented, and these cases probably represent a small fraction of such transitions throughout the Cenozoic. One or more switches have been documented among platyrrhine monkeys, Malagasy prosimians, Eocene omomyids, Eocene adapoids, and early African anthropoids, with inconclusive but suggestive data within tarsiids. The interpretation of living and extinct primates as fitting into one of two diarhythmic categories is itself problematic, because many extant primates show significant behavioral activity both nocturnally and diurnally. Parsimony models routinely interpret ancestral primates to have been nocturnal, but analyses of morphological and genetic data indicate that they may have been diurnal, or that early primate radiations were likely to

  17. Aurally Aided Visual Search Performance Comparing Virtual Audio Systems

    DEFF Research Database (Denmark)

    Larsen, Camilla Horne; Lauritsen, David Skødt; Larsen, Jacob Junker;

    2014-01-01

    Due to increased computational power reproducing binaural hearing in real-time applications, through usage of head-related transfer functions (HRTFs), is now possible. This paper addresses the differences in aurally-aided visual search performance between an HRTF enhanced audio system (3D...... with white dots. The results indicate that 3D audio yields faster search latencies than panning audio, especially with larger amounts of distractors. The applications of this research could fit virtual environments such as video games or virtual simulations....

  18. Frequent Trajectory Patterns Mining for Intelligent Visual Surveillance System

    Institute of Scientific and Technical Information of China (English)

    QU Lin; CHEN Yao-wu

    2009-01-01

    A frequent trajectory patterns mining algorithm is proposed to learn the object activities and classify the trajectories in intelligent visual surveillance system. The distribution patterns of the trajectories were generated by an Apriori based frequent patterns mining algorithm and the trajectories were classified by the frequent trajectory patterns generated. In addition, a fuzzy c-mcans (FCM) based learning algorithm and a mean shift based clustering procedure were used to construct the representation of trajectories. The algorithm can be further used to describe activities and identify anomalies. The experiments on two real scenes show that the algorithm is effective.

  19. K+ Currents in Isolated Vestibular Afferent Calyx Terminals

    National Research Council Canada - National Science Library

    Dhawan, Ritu; Mann, Scott E; Meredith, Frances L; Rennie, Katherine J

    2010-01-01

    Vestibular hair cells transduce mechanical displacements of their hair bundles into an electrical receptor potential which modulates transmitter release and subsequent action potential firing in afferent neurons...

  20. Differential modulation of primary afferent depolarization of segmental and ascending intraspinal collaterals of single muscle afferents in the cat spinal cord.

    Science.gov (United States)

    Rudomin, P; Lomelí, J; Quevedo, J

    2004-06-01

    We examined primary afferent depolarization (PAD) in the anesthetized cat elicited in 109 pairs of intraspinal collaterals of single group I afferents from the gastrocnemius nerve, one of the pair ending in the L3 segment, around the Clarke's column nuclei, and the other in the L6 segment within the intermediate zone. Tests for refractoriness were made to assess whether the responses produced by intraspinal stimulation in the L3 and L6 segments were due to activation of collaterals of the same afferent fiber. PAD in each collateral was estimated by independent computer-controlled measurement of the intraspinal current required to maintain a constant probability of antidromic firing. In most fibers, stimulation of the ipsilateral posterior biceps and semitendinosus (PBSt) nerve with trains of pulses maximal for group I afferents had a qualitatively similar effect but produced a larger PAD in the L6 than in the L3 collaterals. Stimulation of cutaneous nerves (sural and superficial peroneus) with single pulses and of the posterior articular nerve, the ipsilateral reticular formation, nucleus raphe magnus and contralateral motor cortex with trains of pulses often had qualitatively different effects. They could produce PAD and/or facilitate the PBSt-induced PAD in one collateral, and produce PAH and/or inhibit the PAD in the other collateral. These patterns could be changed in a differential manner by sensory or supraspinal conditioning stimulation. In summary, the present investigation suggests that the segmental and ascending collaterals of individual afferents are not fixed routes for information transmission, but parts of dynamic systems in which information transmitted to segmental reflex pathways and to Clarke's column neurons by common sources can be decoupled by sensory and descending inputs and funneled to specific targets according to the motor tasks to be performed.

  1. Engineering a visual system for seeing through fog

    Science.gov (United States)

    Larimer, J.; Pavel, M.; Ahumada, A.; Sweet, B.

    1992-01-01

    We examine the requirements for on-board aircraft sensor systems that would allow pilots to 'see through' poor weather, especially fog, and land and rollout aircraft under conditions that currently cause flight cancellations and airport closures. Three visual aspects of landing and rollout are distinguished: guidance, hazard detection and hazard recognition. The visual features which support the tasks are discussed. Three broad categories of sensor technology are examined: passive millimeter wave (PMMW), imaging radar, and passive infrared (IR). PMMW and imaging radar exhibit good weather penetration, but poor spatial and temporal resolution. Imaging radar exhibits good weather penetration, but typically relies on a flat-earth assumption which can lead to interpretive errors. PMMW systems have a narrow field of view. IR has poorer weather penetration but good spatial resolution. We recommend using both millimeter-wave and infrared sensor systems, blending the images using multiresolution digital-image pyramid-processing technology, and fusing the resulting real-time images with stored database imagery of the same scene.

  2. Development of the navigation system for visually impaired.

    Science.gov (United States)

    Harada, Tetsuya; Kaneko, Yuki; Hirahara, Yoshiaki; Yanashima, Kenji; Magatani, Kazushige

    2004-01-01

    A white cane is a typical support instrument for the visually impaired. They use a white cane for the detection of obstacles while walking. So, the area where they have a mental map, they can walk using white cane without the help of others. However, they cannot walk independently in the unknown area, even if they use a white cane. Because, a white cane is a detecting device for obstacles and not a navigation device for their correct route. Now, we are developing the navigation system for the visually impaired which uses indoor space. In Japan, sometimes colored guide lines to the destination is used for a normal person. These lines are attached on the floor, we can reach the destination, if we walk along one of these line. In our system, a developed new white cane senses one colored guide line, and make notice to an user by vibration. This system recognizes the line of the color stuck on the floor by the optical sensor attached in the white cane. And in order to guide still more smoothly, infrared beacons (optical beacon), which can perform voice guidance, are also used.

  3. The visual system of diurnal raptors: updated review.

    Science.gov (United States)

    González-Martín-Moro, J; Hernández-Verdejo, J L; Clement-Corral, A

    2017-05-01

    Diurnal birds of prey (raptors) are considered the group of animals with highest visual acuity (VA). The purpose of this work is to review all the information recently published about the visual system of this group of animals. A bibliographic search was performed in PubMed. The algorithm used was (raptor OR falcon OR kestrel OR hawk OR eagle) AND (vision OR «visual acuity» OR eye OR macula OR retina OR fovea OR «nictitating membrane» OR «chromatic vision» OR ultraviolet). The search was restricted to the «Title» and «Abstract» fields, and to non-human species, without time restriction. The proposed algorithm located 97 articles. Birds of prey are endowed with the highest VA of the animal kingdom. However most of the works study one individual or a small group of individuals, and the methodology is heterogeneous. The most studied bird is the Peregrine falcon (Falco peregrinus), with an estimated VA of 140 cycles/degree. Some eagles are endowed with similar VA. The tubular shape of the eye, the large pupil, and a high density of photoreceptors make this extraordinary VA possible. In some species, histology and optic coherence tomography demonstrate the presence of 2foveas. The nasal fovea (deep fovea) has higher VA. Nevertheless, the exact function of each fovea is unknown. The vitreous contained in the deep fovea could behave as a third lens, adding some magnification to the optic system. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Assessment of visual space recognition in patients with visual field defects using head mounted display (HMD) system: case study with severe visual field defect.

    Science.gov (United States)

    Sugihara, Shunichi; Tanaka, Toshiaki; Miyasaka, Tomoya; Izumi, Takashi; Shimizu, Koichi

    2013-01-01

    For the quantitative assessment of visual field defects of cerebrovascular patients, we developed a new measurement system that could present various kinds of visual information to the patient. In this system, we use a head mounted display as the display device. The quantitative assessment becomes possible by adding the capability to measure the eye movement and the head movement simultaneously by means of a video apparatus of motion analysis. In our study, we examined the effectiveness of this system by applying it to a patient with serious visual field defects. The visual image of the reduced test paper was presented to the patient, the effect on his/her spatial recognition and eye movement was investigated. The results indicated the increase in the ration of visual search in the reduced side. With the reduced image, the decrease of the angular velocity of eye movement was recognized in the visual search in the defected side. In the motion analysis, the head movement was not observed while the eye movements appeared corresponding to each different conditions. This fact led us to confirm that the patient coped with this kind of test by the eye movement. In this analysis, the effectiveness and the usefulness of the developed system were confirmed that enables us to evaluate the abnormal and compensation movement of the eyes.

  5. The organization of primary afferent depolarization in the isolated spinal cord of the frog

    Science.gov (United States)

    Carpenter, D. O.; Rudomin, P.

    1973-01-01

    those of cutaneous and extensor terminals. 7. The VR-DRPs appear to reflect activity of a negative feed-back loop from extensor motoneurones on to sensory fibres from cutaneous and extensor muscles. This system may have a role in modulating the ballistic movement of the frog. DR-DRPs, on the contrary, are widespread in origin and distribution. PAD from sensory fibres may function to sharpen contrast between incoming afferent information. PMID:4541991

  6. Visualization Component of Vehicle Health Decision Support System

    Science.gov (United States)

    Jacob, Joseph; Turmon, Michael; Stough, Timothy; Siegel, Herbert; Walter, patrick; Kurt, Cindy

    2008-01-01

    The visualization front-end of a Decision Support System (DSS) also includes an analysis engine linked to vehicle telemetry, and a database of learned models for known behaviors. Because the display is graphical rather than text-based, the summarization it provides has a greater information density on one screen for evaluation by a flight controller.This tool provides a system-level visualization of the state of a vehicle, and drill-down capability for more details and interfaces to separate analysis algorithms and sensor data streams. The system-level view is a 3D rendering of the vehicle, with sensors represented as icons, tied to appropriate positions within the vehicle body and colored to indicate sensor state (e.g., normal, warning, anomalous state, etc.). The sensor data is received via an Information Sharing Protocol (ISP) client that connects to an external server for real-time telemetry. Users can interactively pan, zoom, and rotate this 3D view, as well as select sensors for a detail plot of the associated time series data. Subsets of the plotted data can be selected and sent to an external analysis engine to either search for a similar time series in an historical database, or to detect anomalous events. The system overview and plotting capabilities are completely general in that they can be applied to any vehicle instrumented with a collection of sensors. This visualization component can interface with the ISP for data streams used by NASA s Mission Control Center at Johnson Space Center. In addition, it can connect to, and display results from, separate analysis engine components that identify anomalies or that search for past instances of similar behavior. This software supports NASA's Software, Intelligent Systems, and Modeling element in the Exploration Systems Research and Technology Program by augmenting the capability of human flight controllers to make correct decisions, thus increasing safety and reliability. It was designed specifically as a

  7. Effect of acute and chronic bilateral visual deafferentation on c-Fos immunoreactivity in the visual system of adult rats.

    Science.gov (United States)

    Wiedmann, Rhea; Rosahl, Steffen K; Brinker, Thomas; Samii, Madjid; Nakamura, Makoto

    2013-09-01

    In our study we examined acute and chronic changes in c-Fos expression patterns in the visual system of the rat after complete visual deafferentation. In 20 male Lewis rats, the retro-bulbar part of the optic nerve was sectioned bilaterally. Ten animals underwent c-Fos immunohistochemistry after 3 days and 10 animals after 3 weeks examining time-dependent changes. The control group consisted of 10 animals, which did not undergo any surgical manipulation. c-Fos expression in the rat visual system experienced significant changes after acute and chronic bilateral complete visual deafferentation. Acute decrease in c-Fos level was observed in the ventral lateral geniculate nucleus, intergeniculate leaflet, superficial gray layer of the superior colliculus and layers IV and V of the primary visual cortex. After chronic deafferentation, c-Fos expression was also found to be decreased in the optic and deep layers of the superior colliculus and layer VI of the primary visual cortex. No change in c-Fos expression was observed in the dorsal lateral geniculate nucleus and layers I, II and III of the primary visual cortex. This work shows that secondary complete blindness does not lead to uniform decrease in c-Fos levels in all subcortical and cortical brain regions related to vision. These findings provide important information concerning expression of the immediate-early gene product c-Fos in secondary blind rodent models. It may further serve as a relevant baseline finding when electrical stimulation of the visual system is performed, aiding the assessment of visual neuroprosthesis using c-Fos as a functional mapping tool when evaluating different stimulus parameters in blind rodent models.

  8. Development of Network Analysis and Visualization System for KEGG Pathways

    Directory of Open Access Journals (Sweden)

    Dongmin Seo

    2015-07-01

    Full Text Available Big data refers to informationalization technology for extracting valuable information through the use and analysis of large-scale data and, based on that data, deriving plans for response or predicting changes. With the development of software and devices for next generation sequencing, a vast amount of bioinformatics data has been generated recently. Also, bioinformatics data based big-data technology is rising rapidly as a core technology by the bioinformatician, biologist and big-data scientist. KEGG pathway is bioinformatics data for understanding high-level functions and utilities of the biological system. However, KEGG pathway analysis requires a lot of time and effort because KEGG pathways are high volume and very diverse. In this paper, we proposed a network analysis and visualization system that crawl user interest KEGG pathways, construct a pathway network based on a hierarchy structure of pathways and visualize relations and interactions of pathways by clustering and selecting core pathways from the network. Finally, we construct a pathway network collected by starting with an Alzheimer’s disease pathway and show the results on clustering and selecting core pathways from the pathway network.

  9. Rock Visualization System. Technical description (RVS v.3.5)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [FB Engineering, Goeteborg (Sweden)

    2004-03-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. It is a description of RVS version 3.5. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples; Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  10. Rock Visualization System. Technical description (RVS version 3.8)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [Golder Associates AB (Sweden)

    2007-06-15

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 4.0. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carry out a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  11. Rock Visualization System. Technical description (RVS version 3.8)

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, P.; Elfstroem, M.; Markstroem, I. [FB Engineering, Goeteborg (Sweden)

    2005-04-01

    The Rock Visualization System (RVS) has been developed by SKB for use in visualizing geological and engineering data in 3D. The purpose of this report is to provide a technical description of RVS aimed at potential program users and interested parties as well as fulfilling the function of a more general RVS reference that can be cited when writing other technical reports. The report describes RVS version 3.8. Updated versions of this report or addenda will be made available following further development of RVS and the release of subsequent versions of the program. The report covers the following main items: Technical description of the program with illustrations and examples. Limitations of the program and of functionality. For most RVS functions step-by-step tutorials are available describing how a particular function can be used to carryout a specific task. A complete set of updated tutorials is issued with each new version release of the RVS program. However, the tutorials do not cover all the possible uses of all the individual functions but rather give an overall view of their functionality. A detailed description of every RVS function and how it can be used is included in the RVS online Help system.

  12. A New Method to Calibrate Robot Visual Measurement System

    Directory of Open Access Journals (Sweden)

    Yali Wang

    2013-01-01

    Full Text Available This paper presents a new method to calibrate the robot visual measurement system. In the paper, a laser tracker is used to calibrate the robot twist angles. Each axis of the robot is moved to many positions and the positions measured by the laser tracker fit a plane. The normal vectors of the planes are the directions of the Z axes. According to the definition of the robot kinematics model parameters, the errors of the twist angles can be calculated. The joint angles zero offsets are calibrated by the constraint that the rotation relationship between the world frame and the robot base frame is relatively constant. A planar target with several parallel lines is used to obtain the pose of the camera relative to the planar target by the lines in the target plane and the vanishing line of the plane. The quantum behaved particle swarm optimization (QPSO algorithm is used to calculate the parameters. Experiments are performed and the results show that the accuracy of the robot visual measurement system is improved about 10 times after being calibrated.

  13. Komadu: A Capture and Visualization System for Scientific Data Provenance

    Directory of Open Access Journals (Sweden)

    Isuru Suriarachchi

    2015-03-01

    Full Text Available Data provenance captured from scientific applications is a critical precursor to data sharing and reuse. For researchers wanting to repurpose data, it is a source of information about the lineage and attribution of the data and this is needed in order to establish trust in a data set. Komadu is a standalone provenance capture and visualization system for capturing, representing, and manipulating provenance coming from scientific tools, infrastructures, and repositories. It uses the W3C PROV standard [1] in representing data, and it is the successor of the Karma [2] provenance capture system which was based on Open Provenance Model (OPM [3]. Komadu comes with two different interfaces: a Web Services interface based on Apache Axis2 [4] and a messaging interface based on RabbitMQ [5]. Komadu is completely open source and the source code is publicly available on GitHub [6]. Even though Komadu has been used most extensively in relation to scientific research, its interfaces are designed to collect and visualize provenance of any kind of application needing provenance.

  14. Hydrogen sulfide determines HNO-induced stimulation of trigeminal afferents.

    Science.gov (United States)

    Wild, Vanessa; Messlinger, Karl; Fischer, Michael J M

    2015-08-18

    Endogenous NO and hydrogen sulfide form HNO, which causes CGRP release via TRPA1 channel activation in sensory nerves. In the present study, stimulation of intact trigeminal afferent neuron preparations with NO donors, Na2S or both was analyzed by measuring CGRP release as an index of mass activation. Combined stimulation was able to activate all parts of the trigeminal system and acted synergistic compared to stimulation with both substances alone. To investigate the contribution of both substances, we varied their ratio and tracked intracellular calcium in isolated neurons. Our results demonstrate that hydrogen sulfide is the rate-limiting factor for HNO formation. CGRP has a key role in migraine pathophysiology and HNO formation at all sites of the trigeminal system should be considered for this novel means of activation.

  15. A visual-analytics system for railway safety management.

    Science.gov (United States)

    Lira, Wallace P; Alves, Ronnie; Costa, Jean M R; Pessin, Gustavo; Galvao, Lilyan; Cardoso, Ana C; de Souza, Cleidson R B

    2014-01-01

    The working environment of railways is challenging and complex and often involves high-risk operations. These operations affect both the company staff and inhabitants of the towns and cities alongside the railway lines. To reduce the employees' and public's exposure to risk, railway companies adopt strategies involving trained safety personnel, advanced forms of technology, and special work processes. Nevertheless, unfortunate incidents still occur. To assist railway safety management, researchers developed a visual-analytics system. Using a data analytics workflow, it compiles an incident risk index that processes information about railway incidents. It displays the index on a geographical map, together with socioeconomic information about the associated towns and cities. Feedback on this system suggests that safety engineers and experts can use it to make and communicate decisions.

  16. Fluorescent visualization of oxytocin in the hypothalamo-neurohypophysial system

    Directory of Open Access Journals (Sweden)

    Hirofumi eHashimoto

    2014-07-01

    Full Text Available Oxytocin (OXT is well known for its ability to the milk ejection reflex and uterine contraction. It is also involved in several other behaviors, such as anti-nociception, anxiety, feeding, social recognition and stress responses. OXT is synthesized in the magnocellular neurosecretory cells (MNCs in the hypothalamic paraventricular (PVN and the supraoptic nuclei (SON that terminate their axons in the posterior pituitary (PP. We generated transgenic rats that express the OXT and fluorescent protein fusion gene in order to visualize oxytocin in the hypothalamo-neurohypophysial system. In these transgenic rats, fluorescent proteins were observed in the MNCs and axon terminals in the PP. This transgenic rat is a new tool to study the physiological role of OXT in the hypothalamo-neurohypophysial system.

  17. The Astronomy Workshop: Scientific Notation and Solar System Visualizer

    Science.gov (United States)

    Deming, Grace; Hamilton, D.; Hayes-Gehrke, M.

    2008-09-01

    The Astronomy Workshop (http://janus.astro.umd.edu) is a collection of interactive World Wide Web tools that were developed under the direction of Doug Hamilton for use in undergraduate classes and by the general public. The philosophy of the site is to foster student interest in astronomy by exploiting their fascination with computers and the internet. We have expanded the "Scientific Notation” tool from simply converting decimal numbers into and out of scientific notation to adding, subtracting, multiplying, and dividing numbers expressed in scientific notation. Students practice these skills and when confident they may complete a quiz. In addition, there are suggestions on how instructors may use the site to encourage students to practice these basic skills. The Solar System Visualizer animates orbits of planets, moons, and rings to scale. Extrasolar planetary systems are also featured. This research was sponsored by NASA EPO grant NNG06GGF99G.

  18. Integrated Computational System for Aerodynamic Steering and Visualization

    Science.gov (United States)

    Hesselink, Lambertus

    1999-01-01

    In February of 1994, an effort from the Fluid Dynamics and Information Sciences Divisions at NASA Ames Research Center with McDonnel Douglas Aerospace Company and Stanford University was initiated to develop, demonstrate, validate and disseminate automated software for numerical aerodynamic simulation. The goal of the initiative was to develop a tri-discipline approach encompassing CFD, Intelligent Systems, and Automated Flow Feature Recognition to improve the utility of CFD in the design cycle. This approach would then be represented through an intelligent computational system which could accept an engineer's definition of a problem and construct an optimal and reliable CFD solution. Stanford University's role focused on developing technologies that advance visualization capabilities for analysis of CFD data, extract specific flow features useful for the design process, and compare CFD data with experimental data. During the years 1995-1997, Stanford University focused on developing techniques in the area of tensor visualization and flow feature extraction. Software libraries were created enabling feature extraction and exploration of tensor fields. As a proof of concept, a prototype system called the Integrated Computational System (ICS) was developed to demonstrate CFD design cycle. The current research effort focuses on finding a quantitative comparison of general vector fields based on topological features. Since the method relies on topological information, grid matching and vector alignment is not needed in the comparison. This is often a problem with many data comparison techniques. In addition, since only topology based information is stored and compared for each field, there is a significant compression of information that enables large databases to be quickly searched. This report will (1) briefly review the technologies developed during 1995-1997 (2) describe current technologies in the area of comparison techniques, (4) describe the theory of our new

  19. Visual Semantic Based 3D Video Retrieval System Using HDFS.

    Science.gov (United States)

    Kumar, C Ranjith; Suguna, S

    2016-08-01

    This paper brings out a neoteric frame of reference for visual semantic based 3d video search and retrieval applications. Newfangled 3D retrieval application spotlight on shape analysis like object matching, classification and retrieval not only sticking up entirely with video retrieval. In this ambit, we delve into 3D-CBVR (Content Based Video Retrieval) concept for the first time. For this purpose, we intent to hitch on BOVW and Mapreduce in 3D framework. Instead of conventional shape based local descriptors, we tried to coalesce shape, color and texture for feature extraction. For this purpose, we have used combination of geometric & topological features for shape and 3D co-occurrence matrix for color and texture. After thriving extraction of local descriptors, TB-PCT (Threshold Based- Predictive Clustering Tree) algorithm is used to generate visual codebook and histogram is produced. Further, matching is performed using soft weighting scheme with L2 distance function. As a final step, retrieved results are ranked according to the Index value and acknowledged to the user as a feedback .In order to handle prodigious amount of data and Efficacious retrieval, we have incorporated HDFS in our Intellection. Using 3D video dataset, we future the performance of our proposed system which can pan out that the proposed work gives meticulous result and also reduce the time intricacy.

  20. Therapeutic Options for Controlling Fluids in the Visual System

    Science.gov (United States)

    Curry, Kristina M.; Wotring, Virginia E.

    2014-01-01

    Visual Impairment/Intracranial Pressure (VIIP) is a newly recognized risk at NASA. The VIIP project examines the effect of long-term exposure to microgravity on vision of crewmembers before and after they return to Earth. Diamox (acetazolamide) is a medication which is used to decrease intraocular pressure; however, it carries a 3% risk of kidney stones. Astronauts are at a higher risk of kidney stones during spaceflight and the use Diamox would only increase the risk; therefore alternative therapies were investigated. Histamine 2 (H2) antagonist acid blockers such as cimetidine, ranitidine, famotidine and nizatidine are typically used to relieve the symptoms of gastroesophageal reflux disease (GERD). H2 receptors have been found in the human visual system, which has led to research on the use of H2 antagonist blockers to control fluid production in the human eye. Another potential therapeutic strategy is targeted at aquaporins, which are water channels that help maintain fluid homeostasis. Aquaporin antagonists are also known to affect intracranial pressure which can in turn alter intraocular pressure. Studies on aquaporin antagonists suggest high potential for effective treatment. The primary objective of this investigation is to review existing research on alternate medications or therapy to significantly reduce intracranial and intraocular pressure. A literature review was conducted. Even though we do not have all the answers quite yet, a considerable amount of information was discovered, and findings were narrowed, which should allow for more conclusive answers to be found in the near future.

  1. [Effect of work with computer monitors on the visual system].

    Science.gov (United States)

    Niesłuchowska, M

    1994-03-01

    Computer users complain of numerous visual discomforts. The paper discusses those connected with eye fatigue and changes in visual functions associated with the work with monitor screens; these can be alleviated with an ergonomic organization of the work unit. There is a need for a determination of the requirements in visual functions for computer users.

  2. Real-time, interactive, visually updated simulator system for telepresence

    Science.gov (United States)

    Schebor, Frederick S.; Turney, Jerry L.; Marzwell, Neville I.

    1991-01-01

    Time delays and limited sensory feedback of remote telerobotic systems tend to disorient teleoperators and dramatically decrease the operator's performance. To remove the effects of time delays, key components were designed and developed of a prototype forward simulation subsystem, the Global-Local Environment Telerobotic Simulator (GLETS) that buffers the operator from the remote task. GLETS totally immerses an operator in a real-time, interactive, simulated, visually updated artificial environment of the remote telerobotic site. Using GLETS, the operator will, in effect, enter into a telerobotic virtual reality and can easily form a gestalt of the virtual 'local site' that matches the operator's normal interactions with the remote site. In addition to use in space based telerobotics, GLETS, due to its extendable architecture, can also be used in other teleoperational environments such as toxic material handling, construction, and undersea exploration.

  3. Visual tracking in stereo. [by computer vision system

    Science.gov (United States)

    Saund, E.

    1981-01-01

    A method is described for visual object tracking by a computer vision system using TV cameras and special low-level image processing hardware. The tracker maintains an internal model of the location, orientation, and velocity of the object in three-dimensional space. This model is used to predict where features of the object will lie on the two-dimensional images produced by stereo TV cameras. The differences in the locations of features in the two-dimensional images as predicted by the internal model and as actually seen create an error signal in the two-dimensional representation. This is multiplied by a generalized inverse Jacobian matrix to deduce the error in the internal model. The procedure repeats to update the internal model of the object's location, orientation and velocity continuously.

  4. Performance Evaluation of Wavelet Based on Human Visual System

    Institute of Scientific and Technical Information of China (English)

    胡海平; 莫玉龙

    2002-01-01

    We have constructed a compactly supported biorthogonal wavelet that approximates the modulation transfer function(MTF) of human visual system in the frequency domain.In this paper,we evaluate performance of the constructed wavelet,and compare it with the widely used Daubechies9-7,Daubechies 9-3 and GBCW-9-7 wavelets.The result shows that coding performance of the constructed wavelet is better than Daubechies9-3,and is competitive with Daubechies 9-7 and GBCW-9-7 wavelets.Like Dauechies 9-3 wavelet,the filter coefficients of the constructed waveklet are all dyadic fractions,and the tap is less than Daubechies 9-7 and GBOW 9-7,It has an attractive feature in the realization of discrete wavelet transform.

  5. Microlens arrays in the complex visual system of Cretaceous echinoderms.

    Science.gov (United States)

    Gorzelak, Przemysław; Salamon, Mariusz A; Lach, Rafał; Loba, Michał; Ferré, Bruno

    2014-04-01

    It has long been assumed that photosensitivity in echinoderms is mainly related to diffuse photoreception mediated by photosensitive regions embedded within the dermis. Recent studies, however, have shown that some extant echinoderms may also display modified ossicles with microlenses acting as sophisticated photosensory organs. Thanks to their remarkable properties, these calcitic microlenses serve as an inspiration for scientists across various disciplines among which bio-inspired engineering. However, the evolutionary origins of these microlenses remain obscure. Here we provide microstructural evidence showing that analogous spherical calcitic lenses had been acquired in some brittle stars and starfish of Poland by the Late Cretaceous (Campanian, ~79 Ma). Specimens from Poland described here had a highly developed visual system similar to that of modern forms. We suggest that such an optimization of echinoderm skeletons for both mechanical and optical purposes reflects escalation-related adaptation to increased predation pressure during the so-called Mesozoic Marine Revolution.

  6. DESIGN OF A VISUAL INTERFACE FOR ANN BASED SYSTEMS

    Directory of Open Access Journals (Sweden)

    Ramazan BAYINDIR

    2008-01-01

    Full Text Available Artificial intelligence application methods have been used for control of many systems with parallel of technological development besides conventional control techniques. Increasing of artificial intelligence applications have required to education in this area. In this paper, computer based an artificial neural network (ANN software has been presented to learning and understanding of artificial neural networks. By means of the developed software, the training of the artificial neural network according to the inputs provided and a test action can be performed by changing the components such as iteration number, momentum factor, learning ratio, and efficiency function of the artificial neural networks. As a result of the study a visual education set has been obtained that can easily be adapted to the real time application.

  7. Indoor visual positioning system using LED and mobile phone

    Science.gov (United States)

    Gong, Yingkui; Shi, Zhengfa; Wang, Yuqi

    2016-01-01

    An indoor visual positioning system is proposed, which using four or more LED ceiling lamps and a mobile phone. A 4*4 photodiode array is attached to the mobile phone to receive the three-dimensional coordinates of the LED lamps via visible light communication, and the front camera of the mobile phone is used to receive the high resolution image of the LED lamps. The mobile phone's three-dimensional coordinates can be determined by matching the spot information and three-dimensional coordinates of the LED lamps with the image information provided by the mobile phone. An improved collinear equation model is proposed to build the mapping relationship between the three-dimensional coordinates of the LED lamps and the image information acquired by the front camera. A semi-physical simulation has been conducted and analyzed. The positioning scheme is proved to be valid and the positioning accuracy is up to decimeter level.

  8. BrainFrame: a knowledge visualization system for the neurosciences

    Science.gov (United States)

    Barnes, Steven J.; Shaw, Chris D.

    2009-01-01

    Neuroscience has benefited from an explosion of new experimental techniques; many have only become feasible in the wake of improvements in computing speed and data storage. At the same time, these new computation-intensive techniques have led to a growing gulf between the data and the knowledge extracted from those data. That is, in the neurosciences there is a paucity of effective knowledge management techniques and an accelerating accumulation of experimental data. The purpose of the project described in the present paper is to create a visualization of the knowledge base of the neurosciences. At run-time, this 'BrainFrame' project accesses several web-based ontologies and generates a semantically zoomable representation of any one of many levels of the human nervous system.

  9. Visual tracking in stereo. [by computer vision system

    Science.gov (United States)

    Saund, E.

    1981-01-01

    A method is described for visual object tracking by a computer vision system using TV cameras and special low-level image processing hardware. The tracker maintains an internal model of the location, orientation, and velocity of the object in three-dimensional space. This model is used to predict where features of the object will lie on the two-dimensional images produced by stereo TV cameras. The differences in the locations of features in the two-dimensional images as predicted by the internal model and as actually seen create an error signal in the two-dimensional representation. This is multiplied by a generalized inverse Jacobian matrix to deduce the error in the internal model. The procedure repeats to update the internal model of the object's location, orientation and velocity continuously.

  10. Detection of a white dwarf in a visual binary system

    Science.gov (United States)

    Boehm-Vitense, Erika

    1992-01-01

    The F6 giant HD 160365 was detected to have a white dwarf companion about 8 arcsec south of the star. The UV energy distribution observed with IUE shows that the white dwarf has an effective temperature of 23,000 +/- 2000 K. If log g = 8 the Lya profile indicates an effective temperature around 24,500 K. Using the theoretical models by Wesemael et al. (1980) one finds a visual magnitude of m(V) about 16.5. For T(eff) = 24,500 K one expects for a white dwarf a luminosity of log L/L(solar) about 1.3 and M(V) about 10.67. This gives a distance modulus for the system of m(V) - M(V) = 5.83 and an absolute magnitude M(V)= 0.3 for the giant.

  11. Evaluating System Parameters on a Dragonfly using Simulation and Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Bhatele, Abhinav [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jain, Nikhil [Univ. of Illinois, Urbana-Champaign, IL (United States); Livnat, Yarden [Univ. of Utah, Salt Lake City, UT (United States); Pascucci, Valerio [Univ. of Utah, Salt Lake City, UT (United States); Bremer, Peer-Timo [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Utah, Salt Lake City, UT (United States)

    2015-04-24

    The dragon y topology is becoming a popular choice for build- ing high-radix, low-diameter networks with high-bandwidth links. Even with a powerful network, preliminary experi- ments on Edison at NERSC have shown that for communica- tion heavy applications, job interference and thus presumably job placement remains an important factor. In this paper, we explore the e ects of job placement, job sizes, parallel workloads and network con gurations on network through- put to better understand inter-job interference. We use a simulation tool called Damsel y to model the network be- havior of Edison and study the impact of various system parameters on network throughput. Parallel workloads based on ve representative communication patters are used and the simulation studies on up to 131,072 cores are aided by a new visualization of the dragon y network.

  12. The Components of the Visual System of a Dragonfly

    Science.gov (United States)

    Ruck, Philip

    1965-01-01

    In this study of the electroretinograms of dragonflies (adults and nymphs) the objectives were to determine the number of classes of photoreceptors present in the visual system and to allocate these to particular morphological regions. There are probably five classes of photoreceptors present with peak sensitivities near 550, 530, 518, 420, and < 380 mµ. The dorsal ocelli contain two classes (518 mµ and < 380 mµ). The ventral (anterior) ommatidia of the adult compound eye contain at least two classes (near 518 mµ and < 380 mµ) and probably a third class (near 550 mµ). The dorsal ommatidia of the adult compound eye contain one class (420 mµ) and possibly another class (< 380 mµ). The compound eye of the nymph contains one class (530 mµ) and possibly another class (420 mµ). PMID:19873565

  13. New enhancement of infrared image based on human visual system

    Institute of Scientific and Technical Information of China (English)

    Tianhe Yu; Qiuming Li; Jingmin Dai

    2009-01-01

    Infrared images are firstly analyzed using the multifractal theory so that the singularity of each pixel can be extracted from the images. The multifractal spectrum is then estimated, which can reflect overall characteristic of an infrared image. Thus the edge and texture of an infrared image can be accurately extracted based on the singularity of each pixel and the multifractal spectrum. Finally the edge pixels are classified and enhanced in accordance with the sensitivity of human visual system to the edge profile of an infrared image. The experimental results obtained by this approach are compared with those obtained by other methods. It is found that the proposed approach can be used to highlight the edge area of an infrared image to make an infrared image more suitable for observation by human eyes.

  14. The Simulating of the Woven Fabric Visual System

    Institute of Scientific and Technical Information of China (English)

    DENG Zhongmin; LU Hongmei; ZHU Lili

    2006-01-01

    With Visual C++6.0 as the language, following the traditional waterfall model and the software engineering theory, utilizing the technique of the dialog box, picture synthesis in VC, the writers present the developing of the woven fabric CAD system under the environment of Windows98. The system includes weave designing, yarn simulating, color matching, handling hand sample fabric and the testing effect.The basic methods and effect evaluation have been discussed and developed for the weave designing, yarn appearance simulating and fabric color matching, as well as handling hand sample states the image processing, such as DIB(Device-independent bitmap);meanwhile, the developed system has been tested and run in actual design and textile mill trials. The operated results show that the system runs steadily, efficiently and smart, it can be widely used in yarn and fabric design by using with the merits of convenience, celerity and nicety in shortening the developing periods of product; additionally, it provides in fact a new approach to technical design for textile mills.

  15. Ghrelin counteracts insulin-induced activation of vagal afferent neurons via growth hormone secretagogue receptor.

    Science.gov (United States)

    Iwasaki, Yusaku; Dezaki, Katsuya; Kumari, Parmila; Kakei, Masafumi; Yada, Toshihiko

    2015-08-01

    Vagal afferent nerves sense meal-related gastrointestinal and pancreatic hormones and convey their information to the brain, thereby regulating brain functions including feeding. We have recently demonstrated that postprandial insulin directly acts on the vagal afferent neurons. Plasma concentrations of orexigenic ghrelin and anorexigenic insulin show reciprocal dynamics before and after meals. The present study examined interactive effects of ghrelin and insulin on vagal afferent nerves. Cytosolic Ca(2+) concentration ([Ca(2+)]i) in isolated nodose ganglion (NG) neurons was measured to monitor their activity. Insulin at 10(-7)M increased [Ca(2+)]i in NG neurons, and the insulin-induced [Ca(2+)]i increase was inhibited by treatment with ghrelin at 10(-8)M. This inhibitory effect of ghrelin was attenuated by [D-Lys(3)]-GHRP-6, an antagonist of growth hormone-secretagogue receptor (GHSR). Des-acyl ghrelin had little effect on insulin-induced [Ca(2+)]i increases in NG neurons. Ghrelin did not affect [Ca(2+)]i increases in response to cholecystokinin (CCK), a hormone that inhibits feeding via vagal afferent neurons, indicating that ghrelin selectively counteracts the insulin action. These results demonstrate that ghrelin via GHSR suppresses insulin-induced activation of NG neurons. The action of ghrelin to counteract insulin effects on NG might serve to efficiently inform the brain of the systemic change between fasting-associated ghrelin-dominant and fed-associated insulin-dominant states for the homeostatic central regulation of feeding and metabolism.

  16. Synaptic transmission of baro- and chemoreceptors afferents in the NTS second order neurons.

    Science.gov (United States)

    Accorsi-Mendonça, Daniela; Machado, Benedito H

    2013-04-01

    Second order neurons in the nucleus tractus solitarius (NTS) process and integrate the afferent information from arterial baroreceptors with high fidelity and precise timing synaptic transmission. Since 2nd-order NTS neurons receiving baroreceptors inputs are relatively well characterized, their electrophysiological profile has been accepted as a general characteristic for all 2nd-order NTS neurons involved with the processing of different sensorial inputs. On the other hand, the synaptic properties of other afferent systems in NTS, such as the peripheral chemoreceptors, are not yet well understood. In this context, in previous studies we demonstrated that in response to repetitive afferents stimulation, the chemoreceptors 2nd-order NTS neurons also presented high fidelity of synaptic transmission, but with a large variability in the latency of evoked responses. This finding is different in relation to the precise timing transmission for baroreceptor 2nd-order NTS neurons, which was accepted as a general characteristic profile for all 2nd order neurons in the NTS. In this brief review we discuss this new concept as an index of complexity of the sensorial inputs to NTS with focus on the synaptic processing of baro- and chemoreceptor afferents.

  17. Virtual Earth System Laboratory (VESL): Effective Visualization of Earth System Data and Process Simulations

    Science.gov (United States)

    Quinn, J. D.; Larour, E. Y.; Cheng, D. L. C.; Halkides, D. J.

    2016-12-01

    The Virtual Earth System Laboratory (VESL) is a Web-based tool, under development at the Jet Propulsion Laboratory and UC Irvine, for the visualization of Earth System data and process simulations. It contains features geared toward a range of applications, spanning research and outreach. It offers an intuitive user interface, in which model inputs are changed using sliders and other interactive components. Current capabilities include simulation of polar ice sheet responses to climate forcing, based on NASA's Ice Sheet System Model (ISSM). We believe that the visualization of data is most effective when tailored to the target audience, and that many of the best practices for modern Web design/development can be applied directly to the visualization of data: use of negative space, color schemes, typography, accessibility standards, tooltips, etc cetera. We present our prototype website, and invite input from potential users, including researchers, educators, and students.

  18. Iterative development of visual control systems in a research vivarium.

    Directory of Open Access Journals (Sweden)

    James A Bassuk

    Full Text Available The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation, would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and

  19. Iterative development of visual control systems in a research vivarium.

    Science.gov (United States)

    Bassuk, James A; Washington, Ida M

    2014-01-01

    The goal of this study was to test the hypothesis that reintroduction of Continuous Performance Improvement (CPI) methodology, a lean approach to management at Seattle Children's (Hospital, Research Institute, Foundation), would facilitate engagement of vivarium employees in the development and sustainment of a daily management system and a work-in-process board. Such engagement was implemented through reintroduction of aspects of the Toyota Production System. Iterations of a Work-In-Process Board were generated using Shewhart's Plan-Do-Check-Act process improvement cycle. Specific attention was given to the importance of detecting and preventing errors through assessment of the following 5 levels of quality: Level 1, customer inspects; Level 2, company inspects; Level 3, work unit inspects; Level 4, self-inspection; Level 5, mistake proofing. A functioning iteration of a Mouse Cage Work-In-Process Board was eventually established using electronic data entry, an improvement that increased the quality level from 1 to 3 while reducing wasteful steps, handoffs and queues. A visual workplace was realized via a daily management system that included a Work-In-Process Board, a problem solving board and two Heijunka boards. One Heijunka board tracked cage changing as a function of a biological kanban, which was validated via ammonia levels. A 17% reduction in cage changing frequency provided vivarium staff with additional time to support Institute researchers in their mutual goal of advancing cures for pediatric diseases. Cage washing metrics demonstrated an improvement in the flow continuum in which a traditional batch and queue push system was replaced with a supermarket-type pull system. Staff engagement during the improvement process was challenging and is discussed. The collective data indicate that the hypothesis was found to be true. The reintroduction of CPI into daily work in the vivarium is consistent with the 4P Model of the Toyota Way and selected Principles

  20. Application Of Expert System Techniques To A Visual Tracker

    Science.gov (United States)

    Myler, Harley R.; Thompson, Wiley E.; Flachs, Gerald M.

    1985-04-01

    A structure for visual tracking system is presented which relies on information developed from previous tracking scenarios stored in a knowledge base to enhance tracking performance. The system is comprised of a centroid tracker front end which supplies segmented image features to a data reduction algorithm which holds the reduced data in a temporary data base relation. This relation is then classified vio two separate modes, learn and track. Under learn mode, an external teacher-irector operator provides identification and weighting cues for membership in a long-term storage relation within a knowledge base. Track mode operates autonomously from the learn mode where the system determines feature validity by applying fuzzy set membership criteria to previously stored track information in the database. Results determined from the classification generate tracker directives which either enhance or permit current tracking to continue or cause the tracker to search for alternate targets based upon analysis of a global target tracking list. The classification algorithm is based on correlative analysis of the tracker's segmented output presentation after low pass filtering derives lower order harmonics of the feature. The fuzzy set membership criteria is based on size, rotation, Irame location, and past history of the feature. The first three factors are lin-ear operations on the spectra, while the last is generated as a context relation in the knowledge base. The context relation interlinks data between features to facilitate tracker operation during feature occlusion or presence of countermeasures.

  1. Human visual system-based smoking event detection

    Science.gov (United States)

    Odetallah, Amjad D.; Agaian, Sos S.

    2012-06-01

    Human action (e.g. smoking, eating, and phoning) analysis is an important task in various application domains like video surveillance, video retrieval, human-computer interaction systems, and so on. Smoke detection is a crucial task in many video surveillance applications and could have a great impact to raise the level of safety of urban areas, public parks, airplanes, hospitals, schools and others. The detection task is challenging since there is no prior knowledge about the object's shape, texture and color. In addition, its visual features will change under different lighting and weather conditions. This paper presents a new scheme of a system for detecting human smoking events, or small smoke, in a sequence of images. In developed system, motion detection and background subtraction are combined with motion-region-saving, skin-based image segmentation, and smoke-based image segmentation to capture potential smoke regions which are further analyzed to decide on the occurrence of smoking events. Experimental results show the effectiveness of the proposed approach. As well, the developed method is capable of detecting the small smoking events of uncertain actions with various cigarette sizes, colors, and shapes.

  2. High-Frequency Acoustic Flow Visualization (HFAFV) Sonar Systems

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Flow visualization of fluid processes on the continental shelf; e.g., internal tides, ear instabilities, and nonlinear internal gravity waves (solitons)....

  3. Patterns of primary afferent depolarization of segmental and ascending intraspinal collaterals of single joint afferents in the cat.

    Science.gov (United States)

    Rudomin, P; Lomelí, J

    2007-01-01

    We have examined in the anesthetized cat the threshold changes produced by sensory and supraspinal stimuli on intraspinal collaterals of single afferents from the posterior articular nerve (PAN). Forty-eight fibers were tested in the L3 segment, in or close to Clarke's column, and 70 fibers in the L6-L7 segments within the intermediate zone. Of these, 15 pairs of L3 and L6-L7 collaterals were from the same afferent. Antidromically activated fibers had conduction velocities between 23 and 74 m/s and peripheral thresholds between 1.1 and 4.7 times the threshold of the most excitable fibers (xT), most of them below 3 xT. PAN afferents were strongly depolarized by stimulation of muscle afferents and by cutaneous afferents, as well as by stimulation of the bulbar reticular formation and the midline raphe nuclei. Stimulation of muscle nerves (posterior biceps and semitendinosus, quadriceps) produced a larger PAD (primary afferent depolarization) in the L6-L7 than in the L3 terminations. Group II were more effective than group I muscle afferents. As with group I muscle afferents, the PAD elicited in PAN afferents by stimulation of muscle nerves could be inhibited by conditioning stimulation of cutaneous afferents. Stimulation of the cutaneous sural and superficial peroneal nerves increased the threshold of few terminations (i.e., produced primary afferent hyperpolarization, PAH) and reduced the threshold of many others, particularly of those tested in the L6-L7 segments. Yet, there was a substantial number of terminals where these conditioning stimuli had minor or no effects. Autogenetic stimulation of the PAN with trains of pulses increased the intraspinal threshold in 46% and reduced the threshold in 26% of fibers tested in the L6-L7 segments (no tests were made with trains of pulses on fibers ending in L3). These observations indicate that PAN afferents have a rather small autogenetic PAD, particularly if this is compared with the effects of heterogenetic stimulation

  4. Distributed consensus with visual perception in multi-robot systems

    CERN Document Server

    Montijano, Eduardo

    2015-01-01

    This monograph introduces novel responses to the different problems that arise when multiple robots need to execute a task in cooperation, each robot in the team having a monocular camera as its primary input sensor. Its central proposition is that a consistent perception of the world is crucial for the good development of any multi-robot application. The text focuses on the high-level problem of cooperative perception by a multi-robot system: the idea that, depending on what each robot sees and its current situation, it will need to communicate these things to its fellows whenever possible to share what it has found and keep updated by them in its turn. However, in any realistic scenario, distributed solutions to this problem are not trivial and need to be addressed from as many angles as possible. Distributed Consensus with Visual Perception in Multi-Robot Systems covers a variety of related topics such as: ·         distributed consensus algorithms; ·         data association and robustne...

  5. Dissecting Nck/Dock Signaling Pathways in Drosophila Visual System

    Directory of Open Access Journals (Sweden)

    2005-04-01

    Full Text Available The establishment of neuronal connections during embryonic development requires the precise guidance and targeting of the neuronal growth cone, an expanded cellular structure at the leading tip of a growing axon. The growth cone contains sophisticated signaling systems that allow the rapid communication between guidance receptors and the actin cytoskeleton in generating directed motility. Previous studies demonstrated a specific role for the Nck/Dock SH2/SH3 adapter protein in photoreceptor (R cell axon guidance and target recognition in the Drosophila visual system, suggesting strongly that Nck/Dock is one of the long-sought missing links between cell surface receptors and the actin cytoskeleton. In this review, I discuss the recent progress on dissecting the Nck/Dock signaling pathways in R-cell growth cones. These studies have identified additional key components of the Nck/Dock signaling pathways for linking the receptor signaling to the remodeling of the actin cytoskeleton in controlling growth-cone motility.

  6. A General Provincial Situation Visualization System Based on iPhone Operating System of Shandong Province

    Science.gov (United States)

    Ye, Z.; Xiang, H.

    2014-04-01

    The paper discusses the basic principles and the problem solutions during the design and implementation of the mobile GIS system, and base on the research result, we developed the General Provincial Situation Visualization System Based on iOS of Shandong Province. The system is developed in the Objective-C programming language, and use the ArcGIS Runtime SDK for IOS as the development tool to call the "World-map Shandong" services to implement the development of the General Provincial Situation Visualization System Based on iOS devices. The system is currently available for download in the Appstore and is chosen as the typical application case of ESRI China ArcGIS API for iOS.

  7. Visual and Spatial Mental Imagery: Dissociable Systems of Representation.

    Science.gov (United States)

    1987-08-07

    Eisenbc g. 1978. Marmor & Zabeck, 1976), mental scanning tasks (Kerr. 1983). imagery mnemr nic taskq (Jonides, Kahn & Rozin. 1975. Kerr. 1983...40. 362-389 Marmor . G. S.. & Zabeck. L. A. (1976). Mental rotation by the blind: Does mental rotation Visual and Spatial Imagery 30 depend on visual

  8. Hour-long adaptation in the awake early visual system.

    Science.gov (United States)

    Stoelzel, Carl R; Huff, Joseph M; Bereshpolova, Yulia; Zhuang, Jun; Hei, Xiaojuan; Alonso, Jose-Manuel; Swadlow, Harvey A

    2015-08-01

    Sensory adaptation serves to adjust awake brains to changing environments on different time scales. However, adaptation has been studied traditionally under anesthesia and for short time periods. Here, we demonstrate in awake rabbits a novel type of sensory adaptation that persists for >1 h and acts on visual thalamocortical neurons and their synapses in the input layers of the visual cortex. Following prolonged visual stimulation (10-30 min), cells in the dorsal lateral geniculate nucleus (LGN) show a severe and prolonged reduction in spontaneous firing rate. This effect is bidirectional, and prolonged visually induced response suppression is followed by a prolonged increase in spontaneous activity. The reduction in thalamic spontaneous activity following prolonged visual activation is accompanied by increases in 1) response reliability, 2) signal detectability, and 3) the ratio of visual signal/spontaneous activity. In addition, following such prolonged activation of an LGN neuron, the monosynaptic currents generated by thalamic impulses in layer 4 of the primary visual cortex are enhanced. These results demonstrate that in awake brains, prolonged sensory stimulation can have a profound, long-lasting effect on the information conveyed by thalamocortical inputs to the visual cortex.

  9. Vcs.js - Visualization Control System for the Web

    Science.gov (United States)

    Chaudhary, A.; Lipsa, D.; Doutriaux, C.; Beezley, J. D.; Williams, D. N.; Fries, S.; Harris, M. B.

    2016-12-01

    VCS is a general purpose visualization library, optimized for climate data, which is part of the UV-CDAT system. It provides a Python API for drawing 2D plots such as lineplots, scatter plots, Taylor diagrams, data colored by scalar values, vector glyphs, isocontours and map projections. VCS is based on the VTK library. Vcs.js is the corresponding JavaScript API, designed to be as close as possible to the original VCS Python API and to provide similar functionality for the Web. Vcs.js includes additional functionality when compared with VCS. This additional API is used to introspect data files available on the server and variables available in a data file. Vcs.js can display plots in the browser window. It always works with a server that reads a data file, extracts variables from the file and subsets the data. From this point, two alternate paths are possible. First the system can render the data on the server using VCS producing an image which is send to the browser to be displayed. This path works for for all plot types and produces a reference image identical with the images produced by VCS. This path uses the VTK-Web library. As an optimization, usable in certain conditions, a second path is possible. Data is packed, and sent to the browser which uses a JavaScript plotting library, such as plotly, to display the data. Plots that work well in the browser are line-plots, scatter-plots for any data and many other plot types for small data and supported grid types. As web technology matures, more plots could be supported for rendering in the browser. Rendering can be done either on the client or on the server and we expect that the best place to render will change depending on the available web technology, data transfer costs, server management costs and value provided to users. We intend to provide a flexible solution that allows for both client and server side rendering and a meaningful way to choose between the two. We provide a web-based user interface called v

  10. Smart-system of distance learning of visually impaired people based on approaches of artificial intelligence

    Science.gov (United States)

    Samigulina, Galina A.; Shayakhmetova, Assem S.

    2016-11-01

    Research objective is the creation of intellectual innovative technology and information Smart-system of distance learning for visually impaired people. The organization of the available environment for receiving quality education for visually impaired people, their social adaptation in society are important and topical issues of modern education.The proposed Smart-system of distance learning for visually impaired people can significantly improve the efficiency and quality of education of this category of people. The scientific novelty of proposed Smart-system is using intelligent and statistical methods of processing multi-dimensional data, and taking into account psycho-physiological characteristics of perception and awareness learning information by visually impaired people.

  11. Effects of visual and motion simulation cueing systems on pilot performance during takeoffs with engine failures

    Science.gov (United States)

    Parris, B. L.; Cook, A. M.

    1978-01-01

    Data are presented that show the effects of visual and motion during cueing on pilot performance during takeoffs with engine failures. Four groups of USAF pilots flew a simulated KC-135 using four different cueing systems. The most basic of these systems was of the instrument-only type. Visual scene simulation and/or motion simulation was added to produce the other systems. Learning curves, mean performance, and subjective data are examined. The results show that the addition of visual cueing results in significant improvement in pilot performance, but the combined use of visual and motion cueing results in far better performance.

  12. Testing geoscience data visualization systems for geological mapping and training

    Science.gov (United States)

    Head, J. W.; Huffman, J. N.; Forsberg, A. S.; Hurwitz, D. M.; Basilevsky, A. T.; Ivanov, M. A.; Dickson, J. L.; Senthil Kumar, P.

    2008-09-01

    Traditional methods of planetary geological mapping have relied on photographic hard copy and light-table tracing and mapping. In the last several decades this has given way to the availability and analysis of multiple digital data sets, and programs and platforms that permit the viewing and manipulation of multiple annotated layers of relevant information. This has revolutionized the ability to incorporate important new data into the planetary mapping process at all scales. Information on these developments and approaches can be obtained at http://astrogeology.usgs. gov/ Technology/. The processes is aided by Geographic Information Systems (GIS) (see http://astrogeology. usgs.gov/Technology/) and excellent analysis packages (such as ArcGIS) that permit co-registration, rapid viewing, and analysis of multiple data sets on desktop displays (see http://astrogeology.usgs.gov/Projects/ webgis/). We are currently investigating new technological developments in computer visualization and analysis in order to assess their importance and utility in planetary geological analysis and mapping. Last year we reported on the range of technologies available and on our application of these to various problems in planetary mapping. In this contribution we focus on the application of these techniques and tools to Venus geological mapping at the 1:5M quadrangle scale. In our current Venus mapping projects we have utilized and tested the various platforms to understand their capabilities and assess their usefulness in defining units, establishing stratigraphic relationships, mapping structures, reaching consensus on interpretations and producing map products. We are specifically assessing how computer visualization display qualities (e.g., level of immersion, stereoscopic vs. monoscopic viewing, field of view, large vs. small display size, etc.) influence performance on scientific analysis and geological mapping. We have been exploring four different environments: 1) conventional

  13. Sex-dependent neurochemical effects of environmental enrichment in the visual system.

    Science.gov (United States)

    Bessinis, D P; Dalla, C; Kokras, N; Pitychoutis, P M; Papadopoulou-Daifoti, Z

    2013-12-19

    Sex differences in the visual system have been reported in aspects of human vision, such as color perception, peripheral vision and even in the activation of the primary visual cortex. Similarly sex differences have been identified in the visual system of laboratory animals such as monkeys and rats. On the other hand, environmental enrichment (EE) has long been known to affect visual tissues. Taking into consideration the variation in the experimental approaches concerning EE and the sex differences in the visual system, we investigated in male and female rats the serotonergic and dopaminergic effects of EE in the retina and the visual cortex at different time points (i.e. P0-25, P0-P90 and P90-P150). Early EE in adulthood increased the serotonergic activity of the male visual cortex and the female retina (P0-P90). In addition early enrichment (P0-P90) increased dopaminergic activity in the female retina and in the visual cortex of both sexes. Late enrichment increased the serotonergic activity in the retina and visual cortex of both sexes (P90-P150), but increased the dopaminergic activity in the visual cortex only in male animals. In the present study we expose marked sex differences in the neurochemistry of visual tissues and we demonstrate for the first time that EE can in fact modify the serotonergic and dopaminergic neurotransmission in the retina and visual cortex. Overall, the present study underpins the sex-dependent neurochemical status of the visual system and provides insights into the different mechanisms underlying visual processing in the two sexes.

  14. Evaluating the Cognitive Aspects of User Interaction with 2D Visual Tagging Systems

    Directory of Open Access Journals (Sweden)

    Samuel Olugbenga King

    2008-04-01

    Full Text Available There has been significant interest in thedevelopment and deployment of visual taggingapplications in recent times. But user perceptions aboutthe purpose and function of visual tagging systems havenot received much attention. This paper presents a userexperience study that investigates the cognitive modelsthat novice users have about interacting with visualtagging applications. The results of the study show thatalthough most users are unfamiliar with visual taggingtechnologies, they could accurately predict the purposeand mode of retrieval of data stored in visual tags. Thestudy concludes with suggestions on how to improve therecognition, ease of recall and design of visual tags.

  15. Altered visual information processing systems in bipolar disorder: evidence from visual MMN and P3

    Directory of Open Access Journals (Sweden)

    Toshihiko eMaekawa

    2013-07-01

    Full Text Available Objective: Mismatch negativity (MMN and P3 are unique ERP components that provide objective indices of human cognitive functions such as short-term memory and prediction. Bipolar disorder (BD is an endogenous psychiatric disorder characterized by extreme shifts in mood, energy, and ability to function socially. BD patients usually show cognitive dysfunction, and the goal of this study was to access their altered visual information processing via visual MMN (vMMN and P3 using windmill pattern stimuli.Methods: Twenty patients with BD and 20 healthy controls matched for age, gender, and handedness participated in this study. Subjects were seated in front of a monitor and listened to a story via earphones. Two types of windmill patterns (standard and deviant and white circle (target stimuli were randomly presented on the monitor. All stimuli were presented in random order at 200-ms durations with an 800-ms inter-stimulus interval. Stimuli were presented at 80% (standard, 10% (deviant, and 10% (target probabilities. The participants were instructed to attend to the story and press a button as soon as possible when the target stimuli were presented. Event-related potentials were recorded throughout the experiment using 128-channel EEG equipment. vMMN was obtained by subtracting standard from deviant stimuli responses, and P3 was evoked from the target stimulus.Results: Mean reaction times for target stimuli in the BD group were significantly higher than those in the control group. Additionally, mean vMMN-amplitudes and peak P3-amplitudes were significantly lower in the BD group than in controls.Conclusions: Abnormal vMMN and P3 in patients indicate a deficit of visual information processing in bipolar disorder, which is consistent with their increased reaction time to visual target stimuli.Significance: Both bottom-up and top-down visual information processing are likely altered in BD.

  16. Primary afferent response to signals in the intestinal lumen.

    Science.gov (United States)

    Raybould, H

    2001-02-01

    The first recordings of vagal afferent nerve fibre activity were performed by Paintal in the early 1950s. In these experiments, he showed that phenyldiguanide (later recognized as a 5-HT3 receptor agonist) stimulated the firing of C-fibres innervating the intestine. In the following years, ample physiological and psychological studies have demonstrated the importance of afferent information arising from the gut in the regulation of gastrointestinal function and behaviour. Many stimuli are capable of eliciting these functional effects and of stimulating afferent fibre discharge, including mechanical, chemical, nutrient- and immune-derived stimuli. Studies in the last 10 years have begun to focus on the precise sensory transduction mechanisms by which these visceral primary afferent nerve terminals are activated and, like the contribution by Zhu et al. in this issue of The Journal of Physiology, are revealing some novel and exciting findings.

  17. Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study

    Directory of Open Access Journals (Sweden)

    Hitoshi eShitara

    2013-09-01

    Full Text Available Neuroimaging combined with transcranial magnetic stimulation (TMS to primary motor cortex (M1 is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or electrically stimulated the right median nerve (MNS in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG. We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10-20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging.

  18. Creating a portable data-collection system with Microsoft Embedded Visual Tools for the Pocket PC.

    Science.gov (United States)

    Dixon, Mark R

    2003-01-01

    This paper describes an overview and illustrative example for creating a portable data-collection system using Microsoft Embedded Visual Tools for the Pocket PC. A description of the Visual Basic programming language is given, along with examples of computer code procedures for developing data-collection software. Program specifications, strategies for customizing the collection system, and troubleshooting tips are also provided.

  19. Presynaptic selection of afferent inflow in the spinal cord.

    Science.gov (United States)

    Rudomin, P

    1999-01-01

    The synaptic effectiveness of sensory fibers ending in the spinal cord of vertebrates can be centrally controlled by means of specific sets of GABAergic interneurons that make axo-axonic synapses with the terminal arborizations of the afferent fibers. In the steady state, the intracellular concentration of chloride ions in these terminals is higher than that predicted from a passive distribution, because of an active transport mechanism. Following the release of GABA by spinal interneurons and activation of GABA(A) receptors in the afferent terminals, there is an outwardly directed efflux of chloride ions that produces primary afferent depolarization (PAD) and reduces transmitter release (presynaptic inhibition). Studies made by intrafiber recording of PAD, or by measuring changes in the intraspinal threshold of single afferent terminals (which is reduced during PAD), have further indicated that muscle and cutaneous afferents have distinctive, but modifiable PAD patterns in response to segmental and descending stimuli. This has suggested that PAD and presynaptic inhibition in the various types of afferents is mediated by separate sets of last-order GABAergic interneurons. Direct activation, by means of intraspinal microstimulation, of single or small groups of last-order PAD-mediating interneurons shows that the monosynaptic PAD elicited in Ia and Ib afferents can remain confined to some sets of the intraspinal collaterals and not spread to nearby collaterals. The local character of PAD allows cutaneous and descending inputs to selectively inhibit the PAD of segmental and ascending intraspinal collaterals of individual muscle spindle afferents. It thus seems that the intraspinal branches of the sensory fibers are not hard wired routes that diverge excitation to spinal neurons, but are instead dynamic pathways that can be centrally controlled to address information to selected neuronal targets. This feature appears to play an important role in the selection of

  20. Biliary stone causing afferent loop syndrome and pancreatitis

    Institute of Scientific and Technical Information of China (English)

    André Roncon Dias; Roberto Iglesias Lopes

    2006-01-01

    We report the case of an 84-year-old female who had a partial gastrectomy with Billroth-Ⅱ anastomosis 24years ago for a benign peptic ulcer who now presented an acute pancreatitis secondary to an afferent loop syndrome. The syndrome was caused by a gallstone that migrated through a cholecystoenteric fistula. This is the first description in the literature of a biliary stone causing afferent loop syndrome.

  1. Rimonabant induced anorexia in rodents is not mediated by vagal or sympathetic gut afferents

    DEFF Research Database (Denmark)

    Madsen, Andreas Nygaard; Jelsing, Jacob; van de Wall, Esther H E M

    2009-01-01

    The selective CB1 receptor antagonist rimonabant is a novel weight control agent. Although CB1 receptors and binding sites are present in both the rodent central and peripheral nervous systems, including the afferent vagus nerve, the role of gut afferents in mediating anorexia following CB1R...... blockade is still debated. In the present study we examined rimonabant-induced anorexia in male C57BL/6J mice with subdiaphragmatic vagotomy (VGX) as well as in male Sprague-Dawley rats subjected to either subdiaphragmatic vagal deafferentation (SDA) alone or in combination with a complete celiac...... system, are required for rimonabant to inhibit food intake leading to the hypothesis that centrally located CB1 receptors are the prime mediators of rimonabant-induced anorexia....

  2. The Forgotten Tribe in ODL Systems: Challenges Faced by Visually ...

    African Journals Online (AJOL)

    ... Faced by Visually Impaired Students in Institutions of Higher Learning. ... CH Tichauya, CR Alexander, M Paul, D Emanuel ... Data was collected through student interviews and questionnaires for lecturers and thematically analysed.

  3. Reorganization of early visual cortex functional connectivity following selective peripheral and central visual loss.

    Science.gov (United States)

    Sabbah, Norman; Sanda, Nicolae; Authié, Colas N; Mohand-Saïd, Saddek; Sahel, José-Alain; Habas, Christophe; Amedi, Amir; Safran, Avinoam B

    2017-02-24

    Behavioral alterations emerging after central or peripheral vision loss suggest that cerebral reorganization occurs for both the afferented and deafferented early visual cortex (EVC). We explored the functional reorganization of the central and peripheral EVC following visual field defects specifically affecting central or peripheral vision. Compared to normally sighted, afferented central and peripheral EVC enhance their functional connectivity with areas involved in visual processing, whereas deafferented central and peripheral EVC increase their functional connectivity with more remote regions. The connectivity pattern of afferented EVC suggests adaptive changes that might enhance the visual processing capacity whereas the connectivity pattern of deafferented EVC may reflect the involvement of these regions in high-order mechanisms. Characterizing and understanding the plastic changes induced by these visual defects is essential for any attempt to develop efficient rehabilitation strategies.

  4. In pursuit of P2X3 antagonists: novel therapeutics for chronic pain and afferent sensitization.

    Science.gov (United States)

    Ford, Anthony P

    2012-02-01

    Treating pain by inhibiting ATP activation of P2X3-containing receptors heralds an exciting new approach to pain management, and Afferent's program marks the vanguard in a new class of drugs poised to explore this approach to meet the significant unmet needs in pain management. P2X3 receptor subunits are expressed predominately and selectively in so-called C- and Aδ-fiber primary afferent neurons in most tissues and organ systems, including skin, joints, and hollow organs, suggesting a high degree of specificity to the pain sensing system in the human body. P2X3 antagonists block the activation of these fibers by ATP and stand to offer an alternative approach to the management of pain and discomfort. In addition, P2X3 is expressed pre-synaptically at central terminals of C-fiber afferent neurons, where ATP further sensitizes transmission of painful signals. As a result of the selectivity of the expression of P2X3, there is a lower likelihood of adverse effects in the brain, gastrointestinal, or cardiovascular tissues, effects which remain limiting factors for many existing pain therapeutics. In the periphery, ATP (the factor that triggers P2X3 receptor activation) can be released from various cells as a result of tissue inflammation, injury or stress, as well as visceral organ distension, and stimulate these local nociceptors. The P2X3 receptor rationale has aroused a formidable level of investigation producing many reports that clarify the potential role of ATP as a pain mediator, in chronic sensitized states in particular, and has piqued the interest of pharmaceutical companies. P2X receptor-mediated afferent activation has been implicated in inflammatory, visceral, and neuropathic pain states, as well as in airways hyperreactivity, migraine, itch, and cancer pain. It is well appreciated that oftentimes new mechanisms translate poorly from models into clinical efficacy and effectiveness; however, the breadth of activity seen from P2X3 inhibition in models offers

  5. Quantitative and qualitative evaluation of PERCEPT indoor navigation system for visually impaired users.

    Science.gov (United States)

    Ganz, Aura; Schafer, James; Puleo, Elaine; Wilson, Carole; Robertson, Meg

    2012-01-01

    In this paper we introduce qualitative and quantitative evaluation of PERCEPT system, an indoor navigation system for the blind and visually impaired. PERCEPT system trials with 24 blind and visually impaired users in a multi-story building show PERCEPT system effectiveness in providing appropriate navigation instructions to these users. The uniqueness of our system is that it is affordable and that its design follows Orientation and Mobility principles. These results encourage us to generalize the solution to large indoor spaces and test it with significantly larger visually impaired population in diverse settings. We hope that PERCEPT will become a standard deployed in all indoor public spaces.

  6. elVis: An Interactive System For Visualization of Unsteady Fluid Flow

    Science.gov (United States)

    Gerald-Yamasaki, Michael; Lasinski, T. A. (Technical Monitor)

    1995-01-01

    ElVis is a prototype system with allows for the interactive visualization of unsteady fluid flow. The increasing computational power applied to fluid dynamics simulations presents the enormous challenge to the visualization system designer to apply a wide range of technologies to the analysis process with ever increasing demands on performance. Visualization of the results of unsteady fluid flow simulations presents the challenge of exploring very large and complex data sets. Since exploration is a trial and error process, it is of utmost importance that the time required to execute a trial (i.e., create a visualization) be at a minimum in order to provide real time interaction.

  7. Stochastic resonance in the synaptic transmission between hair cells and vestibular primary afferents in development.

    Science.gov (United States)

    Flores, A; Manilla, S; Huidobro, N; De la Torre-Valdovinos, B; Kristeva, R; Mendez-Balbuena, I; Galindo, F; Treviño, M; Manjarrez, E

    2016-05-13

    The stochastic resonance (SR) is a phenomenon of nonlinear systems in which the addition of an intermediate level of noise improves the response of such system. Although SR has been studied in isolated hair cells and in the bullfrog sacculus, the occurrence of this phenomenon in the vestibular system in development is unknown. The purpose of the present study was to explore for the existence of SR via natural mechanical-stimulation in the hair cell-vestibular primary afferent transmission. In vitro experiments were performed on the posterior semicircular canal of the chicken inner ear during development. Our experiments showed that the signal-to-noise ratio of the afferent multiunit activity from E15 to P5 stages of development exhibited the SR phenomenon, which was characterized by an inverted U-like response as a function of the input noise level. The inverted U-like graphs of SR acquired their higher amplitude after the post-hatching stage of development. Blockage of the synaptic transmission with selective antagonists of the NMDA and AMPA/Kainate receptors abolished the SR of the afferent multiunit activity. Furthermore, computer simulations on a model of the hair cell - primary afferent synapse qualitatively reproduced this SR behavior and provided a possible explanation of how and where the SR could occur. These results demonstrate that a particular level of mechanical noise on the semicircular canals can improve the performance of the vestibular system in their peripheral sensory processing even during embryonic stages of development. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Linkwinds, A Visual Data Analysis System and Its Application to Remote Sensed Data

    Science.gov (United States)

    Jacobson, A.; Berkin, A.

    1994-01-01

    The Llinked Windows Interactive Data System is a prototype visual data exploration system resulting from a NASA/JPL program of research into applying graphical methods for rapidly accessing, displaying and analyzing large multivariate multidisciplinary data sets.

  9. Complementary and dynamic type II cadherin expression associated with development of the primate visual system.

    Science.gov (United States)

    Matsunaga, Eiji; Nambu, Sanae; Oka, Mariko; Iriki, Atsushi

    2014-10-01

    The middle temporal visual area (MT, also known as V5) is a visual association area that is particularly evolved in the primate brain. The MT receives input from the primary visual area (V1), constitutes part of the dorsal visual pathway, and plays an essential role in processing motion. Connections between the MT and V1 in the primate brain are formed after birth, and are related to the maturation of visual system. However, it remains to be determined what molecular mechanisms control the formation and maturation of the visual system. Cadherins are transmembrane proteins, originally isolated as cell adhesion molecules, which have multiple roles in synapse formation and function. To investigate potential involvement of cadherins in development of the primate visual system, we examined type II cadherin expression (cadherin-6, -8, -12) in cortical and thalamic visual areas of pre- and postnatal brains of the common marmoset (Callithrix jacchus). In the prenatal brain, cadherin-6 was dominantly expressed in the pulvino-MT pathway whereas cadherin-8 was dominant in the lateral geniculate nucleus (LGN)-V1 pathway. During postnatal development, there was a downregulation of cadherin-6 and upregulation of cadherin-8 expression in the MT. The timing of this cadherin exchange preceded the development of V1-MT connections. Our results suggest the possibility that changes in cadherin expression are involved in the development of the primate visual system, and that a switch in cadherin expression may be a general mechanism to control neural plasticity of highly cognitive abilities.

  10. Geological Visualization System with GPU-Based Interpolation

    Science.gov (United States)

    Huang, L.; Chen, K.; Lai, Y.; Chang, P.; Song, S.

    2011-12-01

    There has been a large number of research using parallel-processing GPU to accelerate the computation. In Near Surface Geology efficient interpolations are critical for proper interpretation of measured data. Additionally, an appropriate interpolation method for generating proper results depends on the factors such as the dense of the measured locations and the estimation model. Therefore, fast interpolation process is needed to efficiently find a proper interpolation algorithm for a set of collected data. However, a general CPU framework has to process each computation in a sequential manner and is not efficient enough to handle a large number of interpolation generally needed in Near Surface Geology. When carefully observing the interpolation processing, the computation for each grid point is independent from all other computation. Therefore, the GPU parallel framework should be an efficient technology to accelerate the interpolation process which is critical in Near Surface Geology. Thus in this paper we design a geological visualization system whose core includes a set of interpolation algorithms including Nearest Neighbor, Inverse Distance and Kriging. All these interpolation algorithms are implemented using both the CPU framework and GPU framework. The comparison between CPU and GPU implementation in the aspect of precision and processing speed shows that parallel computation can accelerate the interpolation process and also demonstrates the possibility of using GPU-equipped personal computer to replace the expensive workstation. Immediate update at the measurement site is the dream of geologists. In the future the parallel and remote computation ability of cloud will be explored to make the mobile computation on the measurement site possible.

  11. The Dynamics of Voluntary Force Production in Afferented Muscle Influence Involuntary Tremor

    Directory of Open Access Journals (Sweden)

    Christopher M Laine

    2016-08-01

    Full Text Available Voluntary control of force is always marked by some degree of error and unsteadiness. Both neural and mechanical factors contribute to these fluctuations, but how they interact to produce them is poorly understood. In this study, we identify and characterize a previously undescribed neuromechanical interaction where the dynamics of voluntary force production suffice to generate involuntary tremor. Specifically, participants were asked to produce isometric force with the index finger and use visual feedback to track a sinusoidal target spanning 5 to 9 % of each individual’s maximal voluntary force level. Force fluctuations and EMG activity over the flexor digitorum superficialis (FDS muscle were recorded and their frequency content was analyzed as a function target phase. Force variability in either the 1 to 5 or 6 to 15 Hz frequency ranges tended to be largest at the peaks and valleys of the target sinusoid. In those same periods, FDS EMG activity was synchronized with force fluctuations. We then constructed a physiologically-realistic computer simulation in which a muscle-tendon complex was set inside of a feedback-driven control loop. Surprisingly, the model sufficed to produce phase-dependent modulation of tremor similar to that observed in humans. Further, the gain of afferent feedback from muscle spindles was critical for appropriately amplifying and shaping this tremor. We suggest that the experimentally-induced tremor may represent the response of a viscoelastic muscle-tendon system to dynamic drive, and therefore does not fall into known categories of tremor generation, such as tremorogenic descending drive, stretch-reflex loop oscillations, motor unit behavior, or mechanical resonance. Our findings motivate future efforts to understand tremor from a perspective that considers neuromechanical coupling within the context of closed-loop control. The strategy of combining experimental recordings with physiologically-sound simulations will

  12. Blindsight and Unconscious Vision: What They Teach Us about the Human Visual System.

    Science.gov (United States)

    Ajina, Sara; Bridge, Holly

    2016-10-23

    Damage to the primary visual cortex removes the major input from the eyes to the brain, causing significant visual loss as patients are unable to perceive the side of the world contralateral to the damage. Some patients, however, retain the ability to detect visual information within this blind region; this is known as blindsight. By studying the visual pathways that underlie this residual vision in patients, we can uncover additional aspects of the human visual system that likely contribute to normal visual function but cannot be revealed under physiological conditions. In this review, we discuss the residual abilities and neural activity that have been described in blindsight and the implications of these findings for understanding the intact system.

  13. Impulse processing: A dynamical systems model of incremental eye movements in the visual world paradigm

    Science.gov (United States)

    Kukona, Anuenue; Tabor, Whitney

    2011-01-01

    The visual world paradigm presents listeners with a challenging problem: they must integrate two disparate signals, the spoken language and the visual context, in support of action (e.g., complex movements of the eyes across a scene). We present Impulse Processing, a dynamical systems approach to incremental eye movements in the visual world that suggests a framework for integrating language, vision, and action generally. Our approach assumes that impulses driven by the language and the visual context impinge minutely on a dynamical landscape of attractors corresponding to the potential eye-movement behaviors of the system. We test three unique predictions of our approach in an empirical study in the visual world paradigm, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the visual world paradigm. PMID:21609355

  14. Afferent innervation of the utricular macula in pigeons

    Science.gov (United States)

    Si, Xiaohong; Zakir, Mridha Md; Dickman, J. David

    2003-01-01

    Biotinylated dextran amine (BDA) was used to retrogradely label afferents innervating the utricular macula in adult pigeons. The pigeon utriclar macula consists of a large rectangular-shaped neuroepithelium with a dorsally curved anterior edge and an extended medioposterior tail. The macula could be demarcated into several regions based on cytoarchitectural differences. The striola occupied 30% of the macula and contained a large density of type I hair cells with fewer type II hair cells. Medial and lateral extrastriola zones were located outside the striola and contained only type II hair cells. A six- to eight-cell-wide band of type II hair cells existed near the center of the striola. The reversal line marked by the morphological polarization of hair cells coursed throughout the epithelium, near the peripheral margin, and through the center of the type II band. Calyx afferents innervated type I hair cells with calyceal terminals that contained between 2 and 15 receptor cells. Calyx afferents were located only in the striola region, exclusive of the type II band, had small total fiber innervation areas and low innervation densities. Dimorph afferents innervated both type I and type II hair cells with calyceal and bouton terminals and were primarily located in the striola region. Dimorph afferents had smaller calyceal terminals with few type I hair cells, extended fiber branches with bouton terminals and larger innervation areas. Bouton afferents innervated only type II hair cells in the extrastriola and type II band regions. Bouton afferents innervating the type II band had smaller terminal fields with fewer bouton terminals and smaller innervation areas than fibers located in the extrastriolar zones. Bouton afferents had the most bouton terminals on the longest fibers, the largest innervation areas with the highest innervation densities of all afferents. Among all afferents, smaller terminal innervation fields were observed in the striola and large fields were

  15. The Design of the Visual Basic Programming Computer Test System%Visual Basic程序设计上机考试系统的设计

    Institute of Scientific and Technical Information of China (English)

    王绍清; 严光银

    2015-01-01

    根据Visual Basic程序设计语言上机考试的实际需求,用Visual Basic语言和Access数据库设计开发了一款“Visual Basic程序设计上机考试系统”,实现了Visual Basic程序设计上机考试的自动组卷、自动计时和自动评分功能。%According to the examination on Computer Operation needs of Visual Basic programming language, using Visual Basic language and Access database was designed and developed a"Visual Basic programming computer test system", realized the com⁃puter Visual Basic programming test Automatic component test paper, automatic timing and automatic grade.

  16. Technical note: real-time web-based wireless visual guidance system for radiotherapy.

    Science.gov (United States)

    Lee, Danny; Kim, Siyong; Palta, Jatinder R; Kim, Taeho

    2017-06-01

    Describe a Web-based wireless visual guidance system that mitigates issues associated with hard-wired audio-visual aided patient interactive motion management systems that are cumbersome to use in routine clinical practice. Web-based wireless visual display duplicates an existing visual display of a respiratory-motion management system for visual guidance. The visual display of the existing system is sent to legacy Web clients over a private wireless network, thereby allowing a wireless setting for real-time visual guidance. In this study, active breathing coordinator (ABC) trace was used as an input for visual display, which captured and transmitted to Web clients. Virtual reality goggles require two (left and right eye view) images for visual display. We investigated the performance of Web-based wireless visual guidance by quantifying (1) the network latency of visual displays between an ABC computer display and Web clients of a laptop, an iPad mini 2 and an iPhone 6, and (2) the frame rate of visual display on the Web clients in frames per second (fps). The network latency of visual display between the ABC computer and Web clients was about 100 ms and the frame rate was 14.0 fps (laptop), 9.2 fps (iPad mini 2) and 11.2 fps (iPhone 6). In addition, visual display for virtual reality goggles was successfully shown on the iPhone 6 with 100 ms and 11.2 fps. A high network security was maintained by utilizing the private network configuration. This study demonstrated that a Web-based wireless visual guidance can be a promising technique for clinical motion management systems, which require real-time visual display of their outputs. Based on the results of this study, our approach has the potential to reduce clutter associated with wired-systems, reduce space requirements, and extend the use of medical devices from static usage to interactive and dynamic usage in a radiotherapy treatment vault.

  17. Hierarchy of Processing Memories in the Human Visual System

    Science.gov (United States)

    Williamson, S. J.; Uusitalo, M. A.

    1997-03-01

    Magnetic source imaging, obtained with an array of 122 superconducting sensors, reveals a dynamical organization of visual cortical areas suggesting that the participation of local memories is an essential component of visual information processing. Response recovery studies provide evidence that each responding cortical area supports a memory function with a well-defined lifetime. The areas fell into two groups: the earliest in occipital lobes with lifetimes ranging from 0.1 to 0.6 s, and the later ones in temporal, parietal, and frontal areas with lifetimes ranging from 7 to 30 s. Also, within each group the areas responding later tended to have longer lifetimes. These hierarchical features introduce a dynamic element that is lacking in many contemporary models of visual processing.

  18. Developing Visualization Support System for Teaching/Learning Database Normalization

    Science.gov (United States)

    Folorunso, Olusegun; Akinwale, AdioTaofeek

    2010-01-01

    Purpose: In tertiary institution, some students find it hard to learn database design theory, in particular, database normalization. The purpose of this paper is to develop a visualization tool to give students an interactive hands-on experience in database normalization process. Design/methodology/approach: The model-view-controller architecture…

  19. Visual System Involvement in Patients with Friedreich's Ataxia

    Science.gov (United States)

    Fortuna, Filippo; Barboni, Piero; Liguori, Rocco; Valentino, Maria Lucia; Savini, Giacomo; Gellera, Cinzia; Mariotti, Caterina; Rizzo, Giovanni; Tonon, Caterina; Manners, David; Lodi, Raffaele; Sadun, Alfredo A.; Carelli, Valerio

    2009-01-01

    Optic neuropathy is common in mitochondrial disorders, but poorly characterized in Friedreich's ataxia (FRDA), a recessive condition caused by lack of the mitochondrial protein frataxin. We investigated 26 molecularly confirmed FRDA patients by studying both anterior and posterior sections of the visual pathway using a new, integrated approach.…

  20. Brain systems for visual perspective taking and action perception.

    Science.gov (United States)

    Mazzarella, Elisabetta; Ramsey, Richard; Conson, Massimiliano; Hamilton, Antonia

    2013-01-01

    Taking another person's viewpoint and making sense of their actions are key processes that guide social behavior. Previous neuroimaging investigations have largely studied these processes separately. The current study used functional magnetic resonance imaging to examine how the brain incorporates another person's viewpoint and actions into visual perspective judgments. Participants made a left-right judgment about the location of a target object from their own (egocentric) or an actor's visual perspective (altercentric). Actor location varied around a table and the actor was either reaching or not reaching for the target object. Analyses examined brain regions engaged in the egocentric and altercentric tasks, brain regions where response magnitude tracked the orientation of the actor in the scene and brain regions sensitive to the action performed by the actor. The blood oxygen level-dependent (BOLD) response in dorsomedial prefrontal cortex (dmPFC) was sensitive to actor orientation in the altercentric task, whereas the response in right inferior frontal gyrus (IFG) was sensitive to actor orientation in the egocentric task. Thus, dmPFC and right IFG may play distinct but complementary roles in visual perspective taking (VPT). Observation of a reaching actor compared to a non-reaching actor yielded activation in lateral occipitotemporal cortex, regardless of task, showing that these regions are sensitive to body posture independent of social context. By considering how an observed actor's location and action influence the neural bases of visual perspective judgments, the current study supports the view that multiple neurocognitive "routes" operate during VPT.

  1. Visual System Involvement in Patients with Friedreich's Ataxia

    Science.gov (United States)

    Fortuna, Filippo; Barboni, Piero; Liguori, Rocco; Valentino, Maria Lucia; Savini, Giacomo; Gellera, Cinzia; Mariotti, Caterina; Rizzo, Giovanni; Tonon, Caterina; Manners, David; Lodi, Raffaele; Sadun, Alfredo A.; Carelli, Valerio

    2009-01-01

    Optic neuropathy is common in mitochondrial disorders, but poorly characterized in Friedreich's ataxia (FRDA), a recessive condition caused by lack of the mitochondrial protein frataxin. We investigated 26 molecularly confirmed FRDA patients by studying both anterior and posterior sections of the visual pathway using a new, integrated approach.…

  2. Personnel Launch System Test On Visual Motion Simulater

    Science.gov (United States)

    1991-01-01

    A research pilot performs a simulated approach and landing in the HL-20 lifting body vehicle. This study, conducted at NASA Langley Research Center's Visual/Motion Simulater, demonstrated the feasibility of the HL-20 as an unpowered glider in landing on a conventional runway.

  3. A Prototypical 3D Graphical Visualizer for Object-Oriented Systems

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    is paper describes a framework for visualizing object-oriented systems within a 3D interactive environment.The 3D visualizer represents the structure of a program as Cylinder Net that simultaneously specifies two relationships between objects within 3D virtual space.Additionally,it represents additional relationships on demand when objects are moved into local focus.The 3D visualizer is implemented using a 3D graphics toolkit,TOAST,that implements 3D Widgets 3D graphics to ease the programming task for 3D visualization.

  4. Visual Complexity in Orthographic Learning: Modeling Learning across Writing System Variations

    Science.gov (United States)

    Chang, Li-Yun; Plaut, David C.; Perfetti, Charles A.

    2016-01-01

    The visual complexity of orthographies varies across writing systems. Prior research has shown that complexity strongly influences the initial stage of reading development: the perceptual learning of grapheme forms. This study presents a computational simulation that examines the degree to which visual complexity leads to grapheme learning…

  5. Interaction Junk: User Interaction-Based Evaluation of Visual Analytic Systems

    Energy Technology Data Exchange (ETDEWEB)

    Endert, Alexander; North, Chris

    2012-10-14

    With the growing need for visualization to aid users in understanding large, complex datasets, the ability for users to interact and explore these datasets is critical. As visual analytic systems have advanced to leverage powerful computational models and data analytics capabilities, the modes by which users engage and interact with the information are limited. Often, users are taxed with directly manipulating parameters of these models through traditional GUIs (e.g., using sliders to directly manipulate the value of a parameter). However, the purpose of user interaction in visual analytic systems is to enable visual data exploration – where users can focus on their task, as opposed to the tool or system. As a result, users can engage freely in data exploration and decision-making, for the purpose of gaining insight. In this position paper, we discuss how evaluating visual analytic systems can be approached through user interaction analysis, where the goal is to minimize the cognitive translation between the visual metaphor and the mode of interaction (i.e., reducing the “Interactionjunk”). We motivate this concept through a discussion of traditional GUIs used in visual analytics for direct manipulation of model parameters, and the importance of designing interactions the support visual data exploration.

  6. Toward a visual cognitive system using active top-down saccadic control

    NARCIS (Netherlands)

    LaCroix, J.; Postma, E.; van den Herik, J.; Murre, J.

    2008-01-01

    The saccadic selection of relevant visual input for preferential processing allows the efficient use of computational resources. Based on saccadic active human vision, we aim to develop a plausible saccade-based visual cognitive system for a humanoid robot. This paper presents two initial steps towa

  7. Child and Symbol Factors in Learning to Read a Visually Complex Writing System

    Science.gov (United States)

    Nag, Sonali; Snowling, Margaret; Quinlan, Philip; Hulme, Charles

    2014-01-01

    In Kannada, visual features are arranged in blocks called "akshara," making this a visually more complex writing system than typical alphabetic orthographies. Akshara knowledge was assessed concurrently and 8 months later in 113 children in the first years of reading instruction (aged 4-7 years). Mixed effects logistic regression models…

  8. Visual Complexity in Orthographic Learning: Modeling Learning across Writing System Variations

    Science.gov (United States)

    Chang, Li-Yun; Plaut, David C.; Perfetti, Charles A.

    2016-01-01

    The visual complexity of orthographies varies across writing systems. Prior research has shown that complexity strongly influences the initial stage of reading development: the perceptual learning of grapheme forms. This study presents a computational simulation that examines the degree to which visual complexity leads to grapheme learning…

  9. Tonic differential supraspinal modulation of PAD and PAH of segmental and ascending intraspinal collaterals of single group I muscle afferents in the cat spinal cord.

    Science.gov (United States)

    Rudomin, P; Lomelí, J; Quevedo, J

    2004-11-01

    We compared in the anesthetized cat the effects of reversible spinalization by cold block on primary afferent depolarization (PAD) and primary afferent hyperpolarization (PAH) elicited in pairs of intraspinal collaterals of single group I afferents from the gastrocnemius nerve, one of the pairs ending in the L3 segment, around the Clarke's column nuclei, and the other in the L6 segment within the intermediate zone. PAD in each collateral was estimated by independent computer-controlled measurement of the intraspinal current required to maintain a constant probability of antidromic firing. The results indicate that the segmental and ascending collaterals of individual afferents are subjected to a tonic PAD of descending origin affecting in a differential manner the excitatory and inhibitory actions of cutaneous and joint afferents on the pathways mediating the PAD of group I fibers. The PAD-mediating networks appear to function as distributed systems whose output will be determined by the balance of the segmental and supraspinal influences received at that moment. It is suggested that the descending differential modulation of PAD enables the intraspinal arborizations of the muscle afferents to function as dynamic systems, in which information transmitted to segmental reflex pathways and to Clarke's column neurons by common sources can be decoupled by sensory and descending inputs, and funneled to specific targets according to the motor tasks to be performed.

  10. VISUAL TEACHING TECHNOLOGY IN IT SYSTEMS FOR THE “MILLENNIAL GENERATION”

    OpenAIRE

    Robert Lis

    2015-01-01

    This publication presents the ongoing development of visual teaching technology in IT systems, which can be used for e-learning for the “Millennial Generation”. The analysis of different models of teaching making use of visual messages, leads to the conclusion that systems more advanced in VPN technologies possess substantial educational qualities. These systems include TightVPN, UltraVNC, OpenVPN, RealVNC or Radmin and ComodoUNITE as well as TeamViewer.

  11. Experience-driven axon retraction in the pharmacologically inactivated visual cortex does not require synaptic transmission.

    Directory of Open Access Journals (Sweden)

    Kana Watanabe

    Full Text Available BACKGROUND: Experience during early postnatal development plays an important role in the refinement of specific neural connections in the brain. In the mammalian visual system, altered visual experiences induce plastic adaptation of visual cortical responses and guide rearrangements of afferent axons from the lateral geniculate nucleus. Previous studies using visual deprivation demonstrated that the afferents serving an open eye significantly retract when cortical neurons are pharmacologically inhibited by applying a gamma-aminobutyric acid type A receptor agonist, muscimol, whereas those serving a deprived eye are rescued from retraction, suggesting that presynaptic activity can lead to the retraction of geniculocortical axons in the absence of postsynaptic activity. Because muscimol application suppresses the spike activity of cortical neurons leaving transmitter release intact at geniculocortical synapses, local synaptic interaction may underlie the retraction of active axons in the inhibited cortex. METHOD AND FINDINGS: New studies reported here determined whether experience-driven axon retraction can occur in the visual cortex inactivated by blocking synaptic inputs. We inactivated the primary visual cortex of kittens by suppressing synaptic transmission with cortical injections of botulinum neurotoxin type E, which cleaves a synaptic protein, SNAP-25, and blocks transmitter release, and examined the geniculocortical axon morphology in the animals with normal vision and those deprived of vision binocularly. We found that afferent axons in the animals with normal vision showed a significant retraction in the inactivated cortex, as similarly observed in the muscimol-treated cortex, whereas the axons in the binocularly deprived animals were preserved. CONCLUSIONS: Therefore, the experience-driven axon retraction in the inactivated cortex can proceed in the absence of synaptic transmission. These results suggest that presynaptic mechanisms play

  12. Dynamics of functional state of sensory visual system of technical specialties students during educational day

    Directory of Open Access Journals (Sweden)

    Rovniy A.S.

    2010-09-01

    Full Text Available The problem of adaptation of students of freshmen is examined to the educational loadings during educational day. In research took part 93 students in the age of 17-18. It is set that the visual sensory system is the indicator of reacting of organism on the different types of fatigue - psychical, mental, physical. It is rotined that playing table tennis is a substantial mean in renewal of functions of the visual sensory system. It is marked that the natural increase of adaptation to the educational loadings reduces the level of functional changes of the visual sensory system.

  13. NMClab, a model to assess the contributions of muscle visco-elasticity and afferent feedback to joint dynamics

    NARCIS (Netherlands)

    Schouten, Alfred C.; Mugge, Winfred; Helm, van der Frans C.T.

    2008-01-01

    The dynamic behavior of a neuromusculoskeletal system results from the complex mechanical interaction between muscle visco-elasticity resulting from (co-)contraction and afferent feedback from muscle spindles and Golgi tendon organs. As a result of the multiple interactions the individual effect of

  14. Patterns of connectivity of spinal interneurons with single muscle afferents.

    Science.gov (United States)

    Quevedo, J; Eguibar, J R; Lomeli, J; Rudomin, P

    1997-07-01

    A technique was developed to measure, in the anesthetized and paralyzed cat under artificial ventilation, changes of excitability to intraspinal stimulation simultaneously in two different afferent fibers or in two collaterals of the same afferent fiber. Intraspinal stimulation reduced the threshold of single muscle afferent fibers ending in the intermediate nucleus. This effect was seen with strengths below those required to activate the afferent fiber tested (1.5-12 microA), occurred at a short latency (1.5-2.0 ms), reached a maximum between 15 and 30 ms, and lasted up to 100 ms. The effects produced by graded stimulation applied at the shortest conditioning-testing stimulus time intervals increased by fixed steps, suggesting recruitment of discrete elements, most likely of last-order interneurons mediating primary afferent depolarization (PAD). The short-latency increases in excitability produced by the weakest effective intraspinal stimuli were usually detected only in the collateral closest to the stimulating micropipette, indicating that the stimulated interneurons mediating PAD have spatially restricted actions. The short-latency PAD produced by intraspinal stimuli, as well as the PAD produced by stimulation of the posterior biceps and semitendinosus (PBSt) nerve or by stimulation of the bulbar reticular formation (RF), was depressed 19-30 min after the i.v. injection of 0.5 mg/kg of picrotoxin, suggesting that all these effects were mediated by GABAergic mechanisms. The PAD elicited by stimulation of muscle and/or cutaneous nerves was depressed following the i.v. injection of (-)-baclofen, whereas the PAD elicited in the same collateral by stimulation of the RF was baclofen-resistant. The short-latency PAD produced by intraspinal stimulation was not always depressed by i.v. injections of (-)-baclofen. Baclofen-sensitive and baclofen-resistant monosynaptic PADs could be produced in different collaterals of the same afferent fiber. The results suggest that

  15. Genioglossus muscle responses to upper airway pressure changes: afferent pathways.

    Science.gov (United States)

    Mathew, O P; Abu-Osba, Y K; Thach, B T

    1982-02-01

    The afferent pathway of an upper airway reflex in which genioglossus muscle electromyographic (GG EMG) activity is influenced by pharyngeal pressure changes was investigated in 20 anesthetized rabbits. We took advantage of the fact that the upper airway was separated into two compartments by pharyngeal closure occurring when the animals breathe through a tracheostomy. This allowed pressure to be delivered selectively either to the nose and nasopharynx or to the larynx and hypopharynx. Midcervical vagotomy did not eliminate the GG EMG response to pressure stimuli. On the other hand high cervical vagotomy or superior laryngeal nerve section eliminated the response in the laryngeal compartment, but not in the nasopharyngeal compartment. Topical anesthesia of the mucosa of the nose, pharynx, and larynx abolished the response in both compartments. Therefore we conclude that more than one afferent pathway exists for this upper airway pressure reflex; the primary afferent pathway from the laryngeal compartment is the superior laryngeal branch of the vagus nerve, whereas the primary afferent pathway for the nasopharynx is nonvagal. Trigeminal nerve, glossopharyngeal nerve, and/or nervus intermedius carry nonvagal afferents from the nasopharynx and nose. The topical anesthetic and nerve section studies suggest that superficial receptors mediate this response. The occurrence of swallowing in response to upper airway pressure changes and its elimination by topical anesthesia or superior mechanoreceptors may mediate both genioglossus respiratory responses and swallowing responses.

  16. Visual cues in low-level flight - Implications for pilotage, training, simulation, and enhanced/synthetic vision systems

    Science.gov (United States)

    Foyle, David C.; Kaiser, Mary K.; Johnson, Walter W.

    1992-01-01

    This paper reviews some of the sources of visual information that are available in the out-the-window scene and describes how these visual cues are important for routine pilotage and training, as well as the development of simulator visual systems and enhanced or synthetic vision systems for aircraft cockpits. It is shown how these visual cues may change or disappear under environmental or sensor conditions, and how the visual scene can be augmented by advanced displays to capitalize on the pilot's excellent ability to extract visual information from the visual scene.

  17. Cortical and white matter mapping in the visual system-more than meets the eye: on the importance of functional imaging to understand visual system pathologies.

    Science.gov (United States)

    Raz, Noa; Levin, Netta

    2014-01-01

    Information transmission within the visual system is highly organized with the ultimate goal of accomplishing higher-order, complex visuo-spatial and object identity processing. Perception is dependent on the intactness of the entire system and damage at each stage-in the eye itself, the visual pathways, or within cortical processing-might result in perception disturbance. Herein we will review several examples of lesions along the visual system, from the retina, via the optic nerve and chiasm and through the occipital cortex. We will address their clinical manifestation and their cortical substrate. The latter will be studied via functional magnetic resonance imaging (fMRI) and Diffusion Tensor Imaging (DTI), enabling cortical, and white matter mapping of the human brain. In contrast to traditional signal recording, these procedures enable simultaneous evaluation of the entire brain network engaged when subjects undertake a particular task or evaluate the entirety of associated white matter pathways. These examples provided will highlight the importance of using advanced imaging methods to better understand visual pathologies. We will argue that clinical manifestation cannot always be explained solely by structural damage and a functional view is required to understand the clinical symptom. In such cases we recommend using advanced imaging methods to better understand the neurological basis of visual phenomena.

  18. Population coding of forelimb joint kinematics by peripheral afferents in monkeys.

    Directory of Open Access Journals (Sweden)

    Tatsuya Umeda

    Full Text Available Various peripheral receptors provide information concerning position and movement to the central nervous system to achieve complex and dexterous movements of forelimbs in primates. The response properties of single afferent receptors to movements at a single joint have been examined in detail, but the population coding of peripheral afferents remains poorly defined. In this study, we obtained multichannel recordings from dorsal root ganglion (DRG neurons in cervical segments of monkeys. We applied the sparse linear regression (SLiR algorithm to the recordings, which selects useful input signals to reconstruct movement kinematics. Multichannel recordings of peripheral afferents were performed by inserting multi-electrode arrays into the DRGs of lower cervical segments in two anesthetized monkeys. A total of 112 and 92 units were responsive to the passive joint movements or the skin stimulation with a painting brush in Monkey 1 and Monkey 2, respectively. Using the SLiR algorithm, we reconstructed the temporal changes of joint angle, angular velocity, and acceleration at the elbow, wrist, and finger joints from temporal firing patterns of the DRG neurons. By automatically selecting a subset of recorded units, the SLiR achieved superior generalization performance compared with a regularized linear regression algorithm. The SLiR selected not only putative muscle units that were responsive to only the passive movements, but also a number of putative cutaneous units responsive to the skin stimulation. These results suggested that an ensemble of peripheral primary afferents that contains both putative muscle and cutaneous units encode forelimb joint kinematics of non-human primates.

  19. Afferent and Efferent Connections of the Cortex-Amygdala Transition Zone in Mice

    Science.gov (United States)

    Cádiz-Moretti, Bernardita; Abellán-Álvaro, María; Pardo-Bellver, Cecília; Martínez-García, Fernando; Lanuza, Enrique

    2016-01-01

    The transitional zone between the ventral part of the piriform cortex and the anterior cortical nucleus of the amygdala, named the cortex-amygdala transition zone (CxA), shows two differential features that allow its identification as a particular structure. First, it receives dense cholinergic and dopaminergic innervations as compared to the adjacent piriform cortex and amygdala, and second, it receives projections from the main and accessory olfactory bulbs. In this work we have studied the pattern of afferent and efferent projections of the CxA, which are mainly unknown, by using the retrograde tracer Fluorogold and the anterograde tracer biotinylated dextranamine. The results show that the CxA receives a relatively restricted set of intratelencephalic connections, originated mainly by the olfactory system and basal forebrain, with minor afferents from the amygdala. The only relevant extratelencephalic afference originates in the ventral tegmental area (VTA). The efferent projections of the CxA reciprocate the inputs from the piriform cortex and olfactory amygdala. In addition, the CxA projects densely to the basolateral amygdaloid nucleus and the olfactory tubercle. The extratelencephalic projections of the CxA are very scarce, and target mainly hypothalamic structures. The pattern of connections of the CxA suggests that it is indeed a transitional area between the piriform cortex and the cortical amygdala. Double labeling with choline acetyltransferase indicates that the afferent projection from the basal forebrain is the origin of its distinctive cholinergic innervation, and double labeling with dopamine transporter shows that the projection from the VTA is the source of dopaminergic innervation. These connectivity and neurochemical features, together with the fact that it receives vomeronasal in addition to olfactory information, suggest that the CxA may be involved in processing olfactory information endowed with relevant biological meaning, such as odors

  20. Psychoactive bacteria Lactobacillus rhamnosus (JB-1) elicits rapid frequency facilitation in vagal afferents.

    Science.gov (United States)

    Perez-Burgos, Azucena; Wang, Bingxian; Mao, Yu-Kang; Mistry, Bhavik; McVey Neufeld, Karen-Anne; Bienenstock, John; Kunze, Wolfgang

    2013-01-15

    Mounting evidence supports the influence of the gut microbiome on the local enteric nervous system and its effects on brain chemistry and relevant behavior. Vagal afferents are involved in some of these effects. We previously showed that ingestion of the probiotic bacterium Lactobacillus rhamnosus (JB-1) caused extensive neurochemical changes in the brain and behavior that were abrogated by prior vagotomy. Because information can be transmitted to the brain via primary afferents encoded as neuronal spike trains, our goal was to record those induced by JB-1 in vagal afferents in the mesenteric nerve bundle and thus determine the nature of the signals sent to the brain. Male Swiss Webster mice jejunal segments were cannulated ex vivo, and serosal and luminal compartments were perfused separately. Bacteria were added intraluminally. We found no evidence for translocation of labeled bacteria across the epithelium during the experiment. We recorded extracellular multi- and single-unit neuronal activity with glass suction pipettes. Within minutes of application, JB-1 increased the constitutive single- and multiunit firing rate of the mesenteric nerve bundle, but Lactobacillus salivarius (a negative control) or media alone were ineffective. JB-1 significantly augmented multiunit discharge responses to an intraluminal distension pressure of 31 hPa. Prior subdiaphragmatic vagotomy abolished all of the JB-1-evoked effects. This detailed exploration of the neuronal spike firing that encodes behavioral signaling to the brain may be useful to identify effective psychoactive bacteria and thereby offer an alternative new perspective in the field of psychiatry and comorbid conditions.

  1. [Three-dimensional morphological modeling and visualization of wheat root system].

    Science.gov (United States)

    Tan, Feng; Tang, Liang; Hu, Jun-Cheng; Jiang, Hai-Yan; Cao, Wei-Xing; Zhu, Yan

    2011-01-01

    Crop three-dimensional (3D) morphological modeling and visualization is an important part of digital plant study. This paper aimed to develop a 3D morphological model of wheat root system based on the parameters of wheat root morphological features, and to realize the visualization of wheat root growth. According to the framework of visualization technology for wheat root growth, a 3D visualization model of wheat root axis, including root axis growth model, branch geometric model, and root axis curve model, was developed firstly. Then, by integrating root topology, the corresponding pixel was determined, and the whole wheat root system was three-dimensionally re-constructed by using the morphological feature parameters in the root morphological model. Finally, based on the platform of OpenGL, and by integrating the technologies of texture mapping, lighting rendering, and collision detection, the 3D visualization of wheat root growth was realized. The 3D output of wheat root system from the model was vivid, which could realize the 3D root system visualization of different wheat cultivars under different water regimes and nitrogen application rates. This study could lay a technical foundation for further development of an integral visualization system of wheat plant.

  2. System and method for image mapping and visual attention

    Science.gov (United States)

    Peters, II, Richard A. (Inventor)

    2011-01-01

    A method is described for mapping dense sensory data to a Sensory Ego Sphere (SES). Methods are also described for finding and ranking areas of interest in the images that form a complete visual scene on an SES. Further, attentional processing of image data is best done by performing attentional processing on individual full-size images from the image sequence, mapping each attentional location to the nearest node, and then summing all attentional locations at each node.

  3. explorase: Multivariate Exploratory Analysis and Visualization for Systems Biology

    OpenAIRE

    2008-01-01

    The datasets being produced by high-throughput biological experiments, such as microarrays, have forced biologists to turn to sophisticated statistical analysis and visualization tools in order to understand their data. We address the particular need for an open-source exploratory data analysis tool that applies numerical methods in coordination with interactive graphics to the analysis of experimental data. The software package, known as explorase, provides a graphical user interface (GUI) ...

  4. Catroid: A Mobile Visual Programming System for Children

    CERN Document Server

    Slany, Wolfgang

    2012-01-01

    Catroid is a free and open source visual programming language, programming environment, image manipulation program, and website. Catroid allows casual and first-time users starting from age eight to develop their own animations and games solely using their Android phones or tablets. Catroid also allows to wirelessly control external hardware such as Lego Mindstorms robots via Bluetooth, Bluetooth Arduino boards, as well as Parrot's popular and inexpensive AR.Drone quadcopters via WiFi.

  5. Data Exchange between CAD System and Visualization System%几何造型系统与可视化系统的数据交换

    Institute of Scientific and Technical Information of China (English)

    李海生; 牛文杰; 杨钦; 陈其明

    2001-01-01

    This paper presents the basic idea of data exchange between CAD system and visualization system which is designed and implemented. As a test,two complex modeling data of geometrical body are read into the visualization system by means of STL file and are triangulated successfully. The result of transferred geometrical body data from CAD system to visualization system is successfully used in analyzing and showing complicated data field and therefore extends the application fields of the visualization system.

  6. Functional and structural connectivity of the visual system in infants with perinatal brain injury.

    Science.gov (United States)

    Merhar, Stephanie L; Gozdas, Elveda; Tkach, Jean A; Harpster, Karen L; Schwartz, Terry L; Yuan, Weihong; Kline-Fath, Beth M; Leach, James L; Altaye, Mekibib; Holland, Scott K

    2016-07-01

    Infants with perinatal brain injury are at risk of later visual problems. Advanced neuroimaging techniques show promise to detect functional and structural alterations of the visual system. We hypothesized that infants with perinatal brain injury would have less brain activation during a visual functional magnetic resonance imaging (fMRI) task and reduced task-based functional connectivity and structural connectivity as compared with healthy controls. Ten infants with perinatal brain injury and 20 control infants underwent visual fMRI and diffusion tensor imaging (DTI) during natural sleep with no sedation. Activation maps, functional connectivity maps, and structural connectivity were analyzed and compared between the two groups. Most infants in both groups had negative activation in the visual cortex during the fMRI task. Infants with brain injury showed reduced activation in the occipital cortex, weaker connectivity between visual areas and other areas of the brain during the visual task, and reduced fractional anisotropy in white matter tracts projecting to visual regions, as compared with control infants. Infants with brain injury sustained in the perinatal period showed evidence of decreased brain activity and functional connectivity during a visual task and altered structural connectivity as compared with healthy term neonates.

  7. A 2D virtual reality system for visual goal-driven navigation in zebrafish larvae

    Science.gov (United States)

    Jouary, Adrien; Haudrechy, Mathieu; Candelier, Raphaël; Sumbre, German

    2016-01-01

    Animals continuously rely on sensory feedback to adjust motor commands. In order to study the role of visual feedback in goal-driven navigation, we developed a 2D visual virtual reality system for zebrafish larvae. The visual feedback can be set to be similar to what the animal experiences in natural conditions. Alternatively, modification of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, we first generated a library of free-swimming behaviors from which we learned the relationship between the trajectory of the larva and the shape of its tail. Then, we used this technique to infer the intended displacements of head-fixed larvae, and updated the visual environment accordingly. Under these conditions, larvae were capable of aligning and swimming in the direction of a whole-field moving stimulus and produced the fine changes in orientation and position required to capture virtual prey. We demonstrate the sensitivity of larvae to visual feedback by updating the visual world in real-time or only at the end of the discrete swimming episodes. This visual feedback perturbation caused impaired performance of prey-capture behavior, suggesting that larvae rely on continuous visual feedback during swimming. PMID:27659496

  8. A 2D virtual reality system for visual goal-driven navigation in zebrafish larvae.

    Science.gov (United States)

    Jouary, Adrien; Haudrechy, Mathieu; Candelier, Raphaël; Sumbre, German

    2016-09-23

    Animals continuously rely on sensory feedback to adjust motor commands. In order to study the role of visual feedback in goal-driven navigation, we developed a 2D visual virtual reality system for zebrafish larvae. The visual feedback can be set to be similar to what the animal experiences in natural conditions. Alternatively, modification of the visual feedback can be used to study how the brain adapts to perturbations. For this purpose, we first generated a library of free-swimming behaviors from which we learned the relationship between the trajectory of the larva and the shape of its tail. Then, we used this technique to infer the intended displacements of head-fixed larvae, and updated the visual environment accordingly. Under these conditions, larvae were capable of aligning and swimming in the direction of a whole-field moving stimulus and produced the fine changes in orientation and position required to capture virtual prey. We demonstrate the sensitivity of larvae to visual feedback by updating the visual world in real-time or only at the end of the discrete swimming episodes. This visual feedback perturbation caused impaired performance of prey-capture behavior, suggesting that larvae rely on continuous visual feedback during swimming.

  9. The cannabinoid system and visual processing: a review on experimental findings and clinical presumptions.

    Science.gov (United States)

    Schwitzer, Thomas; Schwan, Raymund; Angioi-Duprez, Karine; Ingster-Moati, Isabelle; Lalanne, Laurence; Giersch, Anne; Laprevote, Vincent

    2015-01-01

    Cannabis is one of the most prevalent drugs used worldwide. Regular cannabis use is associated with impairments in highly integrative cognitive functions such as memory, attention and executive functions. To date, the cerebral mechanisms of these deficits are still poorly understood. Studying the processing of visual information may offer an innovative and relevant approach to evaluate the cerebral impact of exogenous cannabinoids on the human brain. Furthermore, this knowledge is required to understand the impact of cannabis intake in everyday life, and especially in car drivers. Here we review the role of the endocannabinoids in the functioning of the visual system and the potential involvement of cannabis use in visual dysfunctions. This review describes the presence of the endocannabinoids in the critical stages of visual information processing, and their role in the modulation of visual neurotransmission and visual synaptic plasticity, thereby enabling them to alter the transmission of the visual signal. We also review several induced visual changes, together with experimental dysfunctions reported in cannabis users. In the discussion, we consider these results in relation to the existing literature. We argue for more involvement of public health research in the study of visual function in cannabis users, especially because cannabis use is implicated in driving impairments.

  10. Novel Visual Nasogastric Tube Insertion System: A Feasibility and Efficiency Study in a Manikin.

    Science.gov (United States)

    Li, Qiaoya; Xie, Juan; Wu, Jinxing; Guo, Rui; Ma, Wenwen; Xu, Gang; Yang, Min; Deng, Huisheng

    2016-01-01

    Background. Conventional nasogastric tube placement is an essential clinical procedure; however, complications may arise from blind manipulation. We tested the feasibility and efficiency of a visual nasogastric tube insertion system (VNGS) using a manikin. Methods. A microimaging fiber (0.8 mm) was integrated into the nasogastric tube to create the VNGS. Twenty inexperienced physicians were enrolled and assigned to the visual or conventional group. Each physician performed 10 repeated nasogastric tube insertions with visual guidance or the conventional method; another 20 inexperienced medical students received nasogastric tube insertion training using visual guidance or the conventional method. Results. The nasogastric tube successfully reached the stomach and the narrow anatomic structures were visualized with the VNGS. Time required for insertion was significantly shorter in the visual group compared to the conventional group (22.56 ± 3.08 versus 37.30 ± 4.12 seconds, P visual group. Less mucosal damage was noted in the visual group (3.43 ± 1.63 versus 9.86 ± 2.31 cm(2)). Medical students performed better NGT insertions (shorter insertion time and less procedure-related complications) after undergoing the visual guidance training. Conclusions. The VNGS may provide a new technique for nasogastric tube insertion applicable to clinical use or simulation training.

  11. Chloride regulates afferent arteriolar contraction in response to depolarization

    DEFF Research Database (Denmark)

    Hansen, P B; Jensen, B L; Skott, O

    1998-01-01

    . The results show that K+-induced contraction of smooth muscle cells in the afferent arteriole is highly sensitive to chloride, whereas neurotransmitter release and ensuing contraction is not dependent on chloride. Thus, there are different activation pathways for depolarizing vasoconstrictors......-Renal vascular reactivity is influenced by the level of dietary salt intake. Recent in vitro data suggest that afferent arteriolar contractility is modulated by extracellular chloride. In the present study, we assessed the influence of chloride on K+-induced contraction in isolated perfused rabbit...... afferent arterioles. In 70% of vessels examined, K+-induced contraction was abolished by acute substitution of bath chloride. Consecutive addition of Cl- (30, 60, 80, 100, 110, and 117 mmol/L) restored the sensitivity to K+, and half-maximal response was observed at 82 mmol/L chloride. The calcium channel...

  12. Adipose afferent reflex: sympathetic activation and obesity hypertension.

    Science.gov (United States)

    Xiong, X-Q; Chen, W-W; Zhu, G-Q

    2014-03-01

    Excessive sympathetic activity contributes to the pathogenesis of hypertension and the progression of the related organ damage. Adipose afferent reflex (AAR) is a sympatho-excitatory reflex that the afferent activity from white adipose tissue (WAT) increases sympathetic outflow and blood pressure. Hypothalamic paraventricular nucleus (PVN or PVH) is one of the central sites in the control of the AAR, and ionotropic glutamate receptors in the nucleus mediate the AAR. The AAR is enhanced in obesity and obesity hypertension. Enhanced WAT afferent activity and AAR contribute to the excessive sympathetic activation and hypertension in obesity. Blockage of the AAR attenuates the excessive sympathetic activity and hypertension. Leptin may be one of sensors in the WAT for the AAR, and is involved in the enhanced AAR in obesity and hypertension. This review focuses on the neuroanatomical basis and physiological functions of the AAR, and the important role of the enhanced AAR in the pathogenesis of obesity hypertension.

  13. International Space Station (ISS) SERVIR Environmental Research and Visualization System Photos: 2013-2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The ISS SERVIR Environmental Research and Visualization System (ISERV) acquired images of the Earth's surface from the International Space Station (ISS). The goal...

  14. Experimental System for Investigation of Visual Sensory Input in Postural Feedback Control

    Directory of Open Access Journals (Sweden)

    Jozef Pucik

    2012-01-01

    Full Text Available The human postural control system represents a biological feedback system responsible for maintenance of upright stance. Vestibular, proprioceptive and visual sensory inputs provide the most important information into the control system, which controls body centre of mass (COM in order to stabilize the human body resembling an inverted pendulum. The COM can be measured indirectly by means of a force plate as the centre of pressure (COP. Clinically used measurement method is referred to as posturography. In this paper, the conventional static posturography is extended by visual stimulation, which provides insight into a role of visual information in balance control. Visual stimuli have been designed to induce body sway in four specific directions – forward, backward, left and right. Stabilograms were measured using proposed single-PC based system and processed to calculate velocity waveforms and posturographic parameters. The parameters extracted from pre-stimulus and on-stimulus periods exhibit statistically significant differences.

  15. International Space Station (ISS) SERVIR Environmental Research and Visualization System Photos: 2013-2014

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The ISS SERVIR Environmental Research and Visualization System (ISERV) acquired images of the Earth's surface from the International Space Station (ISS). The goal...

  16. Cloud-Based Social Media Visual Analytics Disaster Response System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a next-generation cloud-based social media visual analytics disaster response system that will enable decision-makers and first-responders to obtain...

  17. Introduction to Information Visualization (InfoVis) Techniques for Model-Based Systems Engineering

    Science.gov (United States)

    Sindiy, Oleg; Litomisky, Krystof; Davidoff, Scott; Dekens, Frank

    2013-01-01

    This paper presents insights that conform to numerous system modeling languages/representation standards. The insights are drawn from best practices of Information Visualization as applied to aerospace-based applications.

  18. VISUAL TEACHING TECHNOLOGY IN IT SYSTEMS FOR THE “MILLENNIAL GENERATION”

    National Research Council Canada - National Science Library

    Robert Lis

    2015-01-01

    ... for the “Millennial Generation”. The analysis of different models of teaching making use of visual messages, leads to the conclusion that systems more advanced in VPN technologies possess substantial educational qualities...

  19. Visual Environment for Rich Data Interpretation (VERDI) program for environmental modeling systems

    Science.gov (United States)

    VERDI is a flexible, modular, Java-based program used for visualizing multivariate gridded meteorology, emissions and air quality modeling data created by environmental modeling systems such as the CMAQ model and WRF.

  20. Envision: An interactive system for the management and visualization of large geophysical data sets

    Science.gov (United States)

    Searight, K. R.; Wojtowicz, D. P.; Walsh, J. E.; Pathi, S.; Bowman, K. P.; Wilhelmson, R. B.

    1995-01-01

    Envision is a software project at the University of Illinois and Texas A&M, funded by NASA's Applied Information Systems Research Project. It provides researchers in the geophysical sciences convenient ways to manage, browse, and visualize large observed or model data sets. Envision integrates data management, analysis, and visualization of geophysical data in an interactive environment. It employs commonly used standards in data formats, operating systems, networking, and graphics. It also attempts, wherever possible, to integrate with existing scientific visualization and analysis software. Envision has an easy-to-use graphical interface, distributed process components, and an extensible design. It is a public domain package, freely available to the scientific community.

  1. Choosing Your Poison: Optimizing Simulator Visual System Selection as a Function of Operational Tasks

    Science.gov (United States)

    Sweet, Barbara T.; Kaiser, Mary K.

    2013-01-01

    Although current technology simulator visual systems can achieve extremely realistic levels they do not completely replicate the experience of a pilot sitting in the cockpit, looking at the outside world. Some differences in experience are due to visual artifacts, or perceptual features that would not be present in a naturally viewed scene. Others are due to features that are missing from the simulated scene. In this paper, these differences will be defined and discussed. The significance of these differences will be examined as a function of several particular operational tasks. A framework to facilitate the choice of visual system characteristics based on operational task requirements will be proposed.

  2. Design of an Eye Limiting Resolution Visual System Using Commercial-Off-the-Shelf Equipment

    Science.gov (United States)

    Sweet, Barbara T.; Giovannetti, Dean P.

    2008-01-01

    A feasibility study was conducted to determine if a flight simulator with an eye-limiting resolution out-the-window (OTW) visual system could be built using commercial off-the-shelf (COTS) technology and used to evaluate the visual performance of Air Force pilots in an operations context. Results of this study demonstrate that an eye limiting OTW visual system can be built using COTS technology. Further, a series of operationally-based tasks linked to clinical vision tests can be used within the synthetic environment to demonstrate a correlation and quantify the level of correlation between vision and operational aviation performance.

  3. Research and Development of Enterprise Information Visual Management System Based on GIS

    Institute of Scientific and Technical Information of China (English)

    YANG Liqing; LI Xunbo

    2006-01-01

    Aiming at managing enterprise information, we have done research and development on enterprise information visual management system based on geographic information system (GIS). In this paper, basis function, design scheme and implement are introduced. Space data and attribute data are supervised with a database. And the functions of GIS, such as display, edit and print, are utilized. The map information and the enterprise information are visually managed and integrally supervised.

  4. Regulation of layer-specific axon targeting in the developing visual system of Drosophila

    OpenAIRE

    Timofeev, K.

    2012-01-01

    The ability of a nervous system to correctly process sensory information depends on the precise wiring of axonal and dendritic projections. The visual system of vertebrates and invertebrates consists of many neuron subtypes, whose neurites are organized into columns and layers. Layered pathways are pivotal to enable parallel processing of several visual features within a network, such as motion and color detection. Despite their functional relevance, the molecular mechanisms controlling their...

  5. A Provenance Visualization Tool for Global Earth Observation System of Systems

    Science.gov (United States)

    Closa Santos, Guillem; Masó Pau, Joan

    2013-04-01

    The widespread use of the distributed environments in the Geographic Information Systems field had generated a broader access and a broader interchange of geographic information. This huge quantity of information, the heterogeneity of the origin of the data, and the complex functionalities involved in the creation of some geographical products can generate some problems in the reliability assessment process. Hence, this can affect to the quality of the results obtained from processing geographic information. In order to increase the trust of the data, the collection and the accessibility of detailed lineage information including responsibilities parties (part of the metadata that refers to the origin and the processes undertaken to obtain a specific geographic product, also known as provenance), is crucial to evaluate the quality of the resulting knowledge, to estimate the trustworthiness level offered by the Agents and the Processes, as well as to allow the reproducibility of the geographical information. Even there are several works related to this topic and some models have been created to integrate provenance information into the metadata standards, there are still some challenges in provenance-aware applications, like the interoperability of the provenance formats, automatic provenance registration and provenance visualization tools. The first goal of this communication is to analyze the state of the art in provenance visualization by comparing different approaches and methods. Secondly, we propose a tool for provenance visualization in Global Earth Observation System of Systems (GEOSS) considering also the relation between provenance information and workflow processing in distributed environments e.g. Web Processing Services. This work is done in the context of the GeoViQua FP7 project.

  6. A method to visualize the evolution of multiple interacting spatial systems

    Science.gov (United States)

    Heitzler, Magnus; Hackl, Jürgen; Adey, Bryan T.; Iosifescu-Enescu, Ionut; Lam, Juan Carlos; Hurni, Lorenz

    2016-07-01

    Integrated modeling approaches are being increasingly used to simulate the behavior of, and the interaction between, several interdependent systems. They are becoming more and more important in many fields, including, but not being limited to, civil engineering, hydrology and climate impact research. It is beneficial when using these approaches to be able to visualize both, the intermediary and final results of scenario-based analyses that are conducted in both, space and time. This requires appropriate visualization techniques that enable to efficiently navigate between multiple such scenarios. In recent years, several innovative visualization techniques have been developed that allow for such navigation purposes. These techniques, however, are limited to the representation of one system at a time. Improvements are possible with respect to the ability to visualize the results related to multiple scenarios for multiple interdependent spatio-temporal systems. To address this issue, existing multi-scenario navigation techniques based on small multiples and line graphs are extended by multiple system representations and inter-system impact representations. This not only allows to understand the evolution of the systems under consideration but also eases identifying events where one system influences another system significantly. In addition, the concept of selective branching is described that allows to remove otherwise redundant information from the visualization by considering the logical and temporal dependencies between these systems. This visualization technique is applied to a risk assessment methodology that allows to determine how different environmental systems (i.e. precipitation, flooding, and landslides) influence each other as well as how their impact on civil infrastructure affects society. The results of this work are concepts for improved visualization techniques for multiple interacting spatial systems. The successful validation with domain experts of

  7. Flow visualization using a computerized data acquisition system

    Science.gov (United States)

    Gallington, R.; Sisson, G.

    1981-01-01

    A computer-driven traversing mechanism combined with mass data storage, data reduction programs, and general-purpose graphics programs permits a visualization of complex flows. A unique seven-hole probe is used which permits reasonably accurate measurements of all average flow properties if the local flow angle does not exceed 80 degrees. A description is given of the wake of a lifting canard surface as this wake passes over a wing. The flow includes concentrated and dissipating vortices, large regions of reduced total pressure, and local flow angles up to 60 deg. All these features can be clearly seen and accurately located in the graphical output.

  8. Integrating a geographic information system, a scientific visualization system and an orographic precipitation model

    Science.gov (United States)

    Hay, L.; Knapp, L.

    1996-01-01

    Investigating natural, potential, and man-induced impacts on hydrological systems commonly requires complex modelling with overlapping data requirements, and massive amounts of one- to four-dimensional data at multiple scales and formats. Given the complexity of most hydrological studies, the requisite software infrastructure must incorporate many components including simulation modelling, spatial analysis and flexible, intuitive displays. There is a general requirement for a set of capabilities to support scientific analysis which, at this time, can only come from an integration of several software components. Integration of geographic information systems (GISs) and scientific visualization systems (SVSs) is a powerful technique for developing and analysing complex models. This paper describes the integration of an orographic precipitation model, a GIS and a SVS. The combination of these individual components provides a robust infrastructure which allows the scientist to work with the full dimensionality of the data and to examine the data in a more intuitive manner.

  9. Constructing a core framework of visual engine for Digital Earth system

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A visual engine is the core of a Digital Earth system.There is a wide variety of functional requirements in Digital Earth system and different requirements correspond to different operations.Based on the development of the visual engine for ChinaStar,a 3D Digital China prototype software platform,and analysis of 3D Digital Earth platforms such as Google Earth,Virtual Earth,Skyline,etc,are discussed.A common core framework for a visual engine is proposed in this paper to construct a visual engine and then with this framework various Digital Earth application systems can be developed efficient.The parametric model of the Earth,scheduling and optimization in visual field,choice of 3D graphics library,and designing component-based visual engine framework of Digital Earth are discussed in detail.In addition,the relationships among these four basic components and the construction of visualization applications of Digital Earth by this method are also discussed.

  10. ProteinVista: a fast molecular visualization system using Microsoft Direct3D.

    Science.gov (United States)

    Park, Chan-Yong; Park, Sung-Hee; Park, Soo-Jun; Park, Sun-Hee; Hwang, Chi-Jung

    2008-09-01

    Many tools have been developed to visualize protein and molecular structures. Most high quality protein visualization tools use the OpenGL graphics library as a 3D graphics system. Currently, the performance of recent 3D graphics hardware has rapidly improved. Recent high-performance 3D graphics hardware support Microsoft Direct3D graphics library more than OpenGL and have become very popular in personal computers (PCs). In this paper, a molecular visualization system termed ProteinVista is proposed. ProteinVista is well-designed visualization system using the Microsoft Direct3D graphics library. It provides various visualization styles such as the wireframe, stick, ball and stick, space fill, ribbon, and surface model styles, in addition to display options for 3D visualization. As ProteinVista is optimized for recent 3D graphics hardware platforms and because it uses a geometry instancing technique, its rendering speed is 2.7 times faster compared to other visualization tools.

  11. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill

    2000-01-01

    in very young infants and in infants with brain damage. We examined 15 preterm infants, 12 children suspected of having a cerebral visual impairment and 10 children with a normal visual system, all of whom were either spontaneously asleep or sedated with chloral hydrate. Cortical response to stroboscopic...... showed a signal decrease. The activated cortical volumes showed a linear relation to age for healthy children younger than 90 weeks PMA, but were small in children with visual impairment. In two children with unilateral damage to the optic radiations, activation was strongly asymmetrical with greatest......Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision...

  12. Functional magnetic resonance imaging of the normal and abnormal visual system in early life

    DEFF Research Database (Denmark)

    Born, A.P.; Miranda Gimenez-Ricco, Maria Jo; Rostrup, Egill;

    2000-01-01

    in very young infants and in infants with brain damage. We examined 15 preterm infants, 12 children suspected of having a cerebral visual impairment and 10 children with a normal visual system, all of whom were either spontaneously asleep or sedated with chloral hydrate. Cortical response to stroboscopic......Functional magnetic resonance imaging (fMRI) in young children may provide information about the development of the visual cortex, and may have predictive value for later visual performance. The purpose of this study was to evaluate the usefulness of fMRI for examining cerebral processing of vision...... showed a signal decrease. The activated cortical volumes showed a linear relation to age for healthy children younger than 90 weeks PMA, but were small in children with visual impairment. In two children with unilateral damage to the optic radiations, activation was strongly asymmetrical with greatest...

  13. Development of the Macro Command Editing Executive System for Factory Workers-Oriented Programless Visual Inspection System

    Science.gov (United States)

    Anezaki, Takashi; Wakitani, Kouichi; Nakamura, Masatoshi; Kubo, Hiroyasu

    Because visual inspection systems are difficult to tune, they create many problems for the kaizen process. This results in increased development costs and time to assure that the inspection systems function properly. In order to improve inspection system development, we designed an easy-tuning system called a “Program-less” visual inspection system. The ROI macro command which consisted of eight kinds of shape recognition macro commands and decision, operation, control commands was built. Furthermore, the macro command editing executive system was developed by the operation of only the GUI without editing source program. The validity of the ROI macro command was proved by the application of 488 places.

  14. Modern Methods of Multidimensional Data Visualization: Analysis, Classification, Implementation, and Applications in Technical Systems

    Directory of Open Access Journals (Sweden)

    I. K. Romanova

    2016-01-01

    Full Text Available The article deals with theoretical and practical aspects of solving the problem of visualization of multidimensional data as an effective means of multivariate analysis of systems. Several classifications are proposed for visualization techniques, according to data types, visualization objects, the method of transformation of coordinates and data. To represent classification are used charts with links to the relevant work. The article also proposes two classifications of modern trends in display technology, including integration of visualization techniques as one of the modern trends of development, along with the introduction of interactive technologies and the dynamics of development processes. It describes some approaches to the visualization problem, which are concerned with fulfilling the needs. The needs are generated by the relevant tasks such as information retrieval in global networks, development of bioinformatics, study and control of business processes, development of regions, etc. The article highlights modern visualization tools, which are capable of improving the efficiency of the multivariate analysis and searching for solutions in multi-objective optimization of technical systems, but are not very actively used for such studies. These are horizontal graphs, graphics "quantile-quantile", etc. The paper proposes to use Choropleth cards traditionally used in cartography for simultaneous presentation of the distribution parameters of several criteria in the space. It notes that visualizations of graphs in network applications can be more actively used to describe the control system. The article suggests using the heat maps to provide graphical representation of the sensitivity of the system quality criteria under variations of options (multivariate analysis of technical systems. It also mentions that it is useful to extend the supervising heat maps to the task of estimating quality of identify in constructing system models. A

  15. Mastering algebra retrains the visual system to perceive hierarchical structure in equations.

    Science.gov (United States)

    Marghetis, Tyler; Landy, David; Goldstone, Robert L

    2016-01-01

    Formal mathematics is a paragon of abstractness. It thus seems natural to assume that the mathematical expert should rely more on symbolic or conceptual processes, and less on perception and action. We argue instead that mathematical proficiency relies on perceptual systems that have been retrained to implement mathematical skills. Specifically, we investigated whether the visual system-in particular, object-based attention-is retrained so that parsing algebraic expressions and evaluating algebraic validity are accomplished by visual processing. Object-based attention occurs when the visual system organizes the world into discrete objects, which then guide the deployment of attention. One classic signature of object-based attention is better perceptual discrimination within, rather than between, visual objects. The current study reports that object-based attention occurs not only for simple shapes but also for symbolic mathematical elements within algebraic expressions-but only among individuals who have mastered the hierarchical syntax of algebra. Moreover, among these individuals, increased object-based attention within algebraic expressions is associated with a better ability to evaluate algebraic validity. These results suggest that, in mastering the rules of algebra, people retrain their visual system to represent and evaluate abstract mathematical structure. We thus argue that algebraic expertise involves the regimentation and reuse of evolutionarily ancient perceptual processes. Our findings implicate the visual system as central to learning and reasoning in mathematics, leading us to favor educational approaches to mathematics and related STEM fields that encourage students to adapt, not abandon, their use of perception.

  16. A visual warning system to reduce struck-by or pinning accidents involving mobile mining equipment.

    Science.gov (United States)

    Sammarco, J; Gallagher, S; Mayton, A; Srednicki, J

    2012-11-01

    This paper describes an experiment to examine whether a visual warning system can improve detection of moving machine hazards that could result in struck-by or pinning accidents. Thirty-six participants, twelve each in one of three age groups, participated in the study. A visual warning system capable of providing four different modes of warning was installed on a continuous mining machine that is used to mine coal. The speed of detecting various machine movements was recorded with and without the visual warning system. The average speed of detection for forward and reverse machine movements was reduced by 75% when using the flashing mode of the visual warning system. This translated to 0.485 m of machine travel for the fast speed condition of 19.8 m/min, which is significant in the context of the confined spaces of a mine. There were no statistically significant differences among age groups in the ability to detect machine movements for the visual warning modes in this study. The visual warning system shows promise as a safety intervention for reducing struck-by or pinning accidents involving continuous mining machines. The methods and results of this study could be applied to other moving machinery used in mining or other industries where moving machinery poses struck-by or pinning hazards.

  17. Developing a personal computer-based data visualization system using public domain software

    Science.gov (United States)

    Chen, Philip C.

    1999-03-01

    The current research will investigate the possibility of developing a computing-visualization system using a public domain software system built on a personal computer. Visualization Toolkit (VTK) is available on UNIX and PC platforms. VTK uses C++ to build an executable. It has abundant programming classes/objects that are contained in the system library. Users can also develop their own classes/objects in addition to those existing in the class library. Users can develop applications with any of the C++, Tcl/Tk, and JAVA environments. The present research will show how a data visualization system can be developed with VTK running on a personal computer. The topics will include: execution efficiency; visual object quality; availability of the user interface design; and exploring the feasibility of the VTK-based World Wide Web data visualization system. The present research will feature a case study showing how to use VTK to visualize meteorological data with techniques including, iso-surface, volume rendering, vector display, and composite analysis. The study also shows how the VTK outline, axes, and two-dimensional annotation text and title are enhancing the data presentation. The present research will also demonstrate how VTK works in an internet environment while accessing an executable with a JAVA application programing in a webpage.

  18. A visual servo-based teleoperation robot system for closed diaphyseal fracture reduction.

    Science.gov (United States)

    Li, Changsheng; Wang, Tianmiao; Hu, Lei; Zhang, Lihai; Du, Hailong; Zhao, Lu; Wang, Lifeng; Tang, Peifu

    2015-09-01

    Common fracture treatments include open reduction and intramedullary nailing technology. However, these methods have disadvantages such as intraoperative X-ray radiation, delayed union or nonunion and postoperative rotation. Robots provide a novel solution to the aforementioned problems while posing new challenges. Against this scientific background, we develop a visual servo-based teleoperation robot system. In this article, we present a robot system, analyze the visual servo-based control system in detail and develop path planning for fracture reduction, inverse kinematics, and output forces of the reduction mechanism. A series of experimental tests is conducted on a bone model and an animal bone. The experimental results demonstrate the feasibility of the robot system. The robot system uses preoperative computed tomography data to realize high precision and perform minimally invasive teleoperation for fracture reduction via the visual servo-based control system while protecting surgeons from radiation.

  19. Autonomic control of the heart during exercise in humans: role of skeletal muscle afferents.

    Science.gov (United States)

    Fisher, James P

    2014-02-01

    What is the topic of this review? The autonomic nervous system plays a key role in bringing about the cardiovascular responses to exercise necessitated by the increased metabolic requirements of the active skeletal muscle. The complex interaction of central and peripheral neural control mechanisms evokes a decrease in parasympathetic activity and an increase sympathetic activity to the heart during exercise. What advances does it highlight? This review presents some of the recent insights provided by human studies into the role of mechanically and metabolically sensitive skeletal muscle afferents in the regulation of cardiac autonomic control during exercise. The autonomic responses to exercise are orchestrated by the interactions of several central and peripheral neural mechanisms. This report focuses on the role of peripheral feedback from skeletal muscle afferents in the autonomic control of the heart during exercise in humans. Heart rate responses to passive calf stretch are abolished with cardiac parasympathetic blockade, indicating that the activation of mechanically sensitive skeletal muscle afferents (muscle mechanoreceptors) can inhibit cardiac parasympathetic activity and is likely to contribute to the increase in heart rate at the onset of exercise. Recent experiments show that the partial restriction of blood flow to the exercising skeletal muscles, to augment the activation of metabolically sensitive skeletal muscle afferents (muscle metaboreceptors) in humans, evokes an increase in heart rate that is attenuated with β1-adrenergic blockade, thus suggesting that this response is principally mediated via an increase in cardiac sympathetic activity. Heart rate remains at resting levels during isolated activation of muscle metaboreceptors with postexercise ischaemia following hand grip, unless cardiac parasympathetic activity is inhibited, whereupon a sympathetically mediated increase in heart rate is unmasked. During postexercise ischaemia following leg

  20. A Port-Hamiltonian Approach to Visual Servo Control of a Pick and Place System

    NARCIS (Netherlands)

    Dirksz, Daniel A.; Scherpen, Jacquelien M. A.; Steinbuch, Maarten

    In this paper, we take a port-Hamiltonian approach to address the problem of image-based visual servo control of a pick and place system. Through a coordinate transformation and a passive interconnection between mechanical system and camera dynamics we realize a closed-loop system that is

  1. Assessment of visual space recognition of patients with unilateral spatial neglect and visual field defects using a head mounted display system.

    Science.gov (United States)

    Sugihara, Shunichi; Tanaka, Toshiaki; Miyasaka, Tomoya; Izumi, Takashi; Shimizu, Koichi

    2016-01-01

    [Purpose] The purpose of this study was the development of a method for presenting diverse visual information and assessing visual space recognition using a new head mounted display (HMD) system. [Subjects] Eight patients: four with unilateral spatial neglect (USN) and four with visual field defects (VFD). [Methods] A test sheet was placed on a desk, and its image was projected on the display of the HMD. Then, space recognition assessment was conducted using a cancellation test and motion analysis of the eyeballs and head under four conditions with images reduced in size and shifted. [Results] Leftward visual search was dominant in VFD patients, while rightward visual search was dominant in USN patients. The angular velocity of leftward eye movement during visual search of the right sheet decreased in both patient types. Motion analysis revealed a tendency of VFD patients to rotate the head in the affected direction under the left reduction condition, whereas USN patients rotated it in the opposite direction of the neglect. [Conclusion] A new HMD system was developed for presenting diverse visual information and assessing visual space recognition which identified the differences in the disturbance of visual space recognition of VFD and USN patients were indicated.

  2. Broad characterization of endogenous peptides in the tree shrew visual system.

    Science.gov (United States)

    Ranc, Vaclav; Petruzziello, Filomena; Kretz, Robert; Argandoña, Enrike G; Zhang, Xiaozhe; Rainer, Gregor

    2012-05-17

    Endogenous neuropeptides, acting as neurotransmitters or hormones in the brain, carry out important functions including neural plasticity, metabolism and angiogenesis. Previous neuropeptide studies have focused on peptide-rich brain regions such as the striatum or hypothalamus. Here we present an investigation of peptides in the visual system, composed of brain regions that are generally less rich in peptides, with the aim of providing the first broad overview of peptides involved in mammalian visual functions. We target three important parts of the visual system: the primary visual cortex (V1), lateral geniculate nucleus (LGN) and superior colliculus (SC). Our study is performed in the tree shrew, a close relative of primates. Using a combination of data dependent acquisition and targeted LC-MS/MS based neuropeptidomics; we identified a total of 52 peptides from the tree shrew visual system. A total of 26 peptides, for example GAV and neuropeptide K were identified in the visual system for the first time. Out of the total 52 peptides, 27 peptides with high signal-to-noise-ratio (>10) in extracted ion chromatograms (EIC) were subjected to label-free quantitation. We observed generally lower abundance of peptides in the LGN compared to V1 and SC. Consistently, a number of individual peptides showed high abundance in V1 (such as neuropeptide Y or somatostatin 28) and in SC (such as somatostatin 28 AA1-12). This study provides the first in-depth characterization of peptides in the mammalian visual system. These findings now permit the investigation of neuropeptide-regulated mechanisms of visual perception.

  3. Visual Analysis of Nonlinear Dynamical Systems: Chaos, Fractals, Self-Similarity and the Limits of Prediction

    Directory of Open Access Journals (Sweden)

    Geoff Boeing

    2016-11-01

    Full Text Available Nearly all nontrivial real-world systems are nonlinear dynamical systems. Chaos describes certain nonlinear dynamical systems that have a very sensitive dependence on initial conditions. Chaotic systems are always deterministic and may be very simple, yet they produce completely unpredictable and divergent behavior. Systems of nonlinear equations are difficult to solve analytically, and scientists have relied heavily on visual and qualitative approaches to discover and analyze the dynamics of nonlinearity. Indeed, few fields have drawn as heavily from visualization methods for their seminal innovations: from strange attractors, to bifurcation diagrams, to cobweb plots, to phase diagrams and embedding. Although the social sciences are increasingly studying these types of systems, seminal concepts remain murky or loosely adopted. This article has three aims. First, it argues for several visualization methods to critically analyze and understand the behavior of nonlinear dynamical systems. Second, it uses these visualizations to introduce the foundations of nonlinear dynamics, chaos, fractals, self-similarity and the limits of prediction. Finally, it presents Pynamical, an open-source Python package to easily visualize and explore nonlinear dynamical systems’ behavior.

  4. Gut chemosensing: interactions between gut endocrine cells and visceral afferents.

    Science.gov (United States)

    Raybould, Helen E

    2010-02-16

    Chemosensing in the gastrointestinal tract is less well understood than many aspects of gut mechanosensitivity; however, it is important in the overall function of the GI tract and indeed the organism as a whole. Chemosensing in the gut represents a complex interplay between the function of enteroendocrine (EEC) cells and visceral (primarily vagal) afferent neurons. In this brief review, I will concentrate on a new data on endocrine cells in chemosensing in the GI tract, in particular on new findings on glucose-sensing by gut EEC cells and the importance of incretin peptides and vagal afferents in glucose homeostasis, on the role of G protein coupled receptors in gut chemosensing, and on the possibility that gut endocrine cells may be involved in the detection of a luminal constituent other than nutrients, the microbiota. The role of vagal afferent pathways as a downstream target of EEC cell products will be considered and, in particular, exciting new data on the plasticity of the vagal afferent pathway with respect to expression of receptors for GI hormones and how this may play a role in energy homeostasis will also be discussed.

  5. PERCEPT Indoor Navigation System for the Blind and Visually Impaired: Architecture and Experimentation

    Directory of Open Access Journals (Sweden)

    Aura Ganz

    2012-01-01

    Full Text Available We introduce PERCEPT system, an indoor navigation system for the blind and visually impaired. PERCEPT will improve the quality of life and health of the visually impaired community by enabling independent living. Using PERCEPT, blind users will have independent access to public health facilities such as clinics, hospitals, and wellness centers. Access to healthcare facilities is crucial for this population due to the multiple health conditions that they face such as diabetes and its complications. PERCEPT system trials with 24 blind and visually impaired users in a multistory building show PERCEPT system effectiveness in providing appropriate navigation instructions to these users. The uniqueness of our system is that it is affordable and that its design follows orientation and mobility principles. We hope that PERCEPT will become a standard deployed in all indoor public spaces, especially in healthcare and wellness facilities.

  6. Robust and Cooperative Image-Based Visual Servoing System Using a Redundant Architecture

    Directory of Open Access Journals (Sweden)

    Francisco J. Badesa

    2011-12-01

    Full Text Available The reliability and robustness of image-based visual servoing systems is still unsolved by the moment. In order to address this issue, a redundant and cooperative 2D visual servoing system based on the information provided by two cameras in eye-in-hand/eye-to-hand configurations is proposed. Its control law has been defined to assure that the whole system is stable if each subsystem is stable and to allow avoiding typical problems of image-based visual servoing systems like task singularities, features extraction errors, disappearance of image features, local minima, etc. Experimental results with an industrial robot manipulator based on Schunk modular motors to demonstrate the stability, performance and robustness of the proposed system are presented.

  7. PERCEPT Indoor Navigation System for the Blind and Visually Impaired: Architecture and Experimentation.

    Science.gov (United States)

    Ganz, Aura; Schafer, James; Gandhi, Siddhesh; Puleo, Elaine; Wilson, Carole; Robertson, Meg

    2012-01-01

    We introduce PERCEPT system, an indoor navigation system for the blind and visually impaired. PERCEPT will improve the quality of life and health of the visually impaired community by enabling independent living. Using PERCEPT, blind users will have independent access to public health facilities such as clinics, hospitals, and wellness centers. Access to healthcare facilities is crucial for this population due to the multiple health conditions that they face such as diabetes and its complications. PERCEPT system trials with 24 blind and visually impaired users in a multistory building show PERCEPT system effectiveness in providing appropriate navigation instructions to these users. The uniqueness of our system is that it is affordable and that its design follows orientation and mobility principles. We hope that PERCEPT will become a standard deployed in all indoor public spaces, especially in healthcare and wellness facilities.

  8. Impulse processing: a dynamical systems model of incremental eye movements in the visual world paradigm.

    Science.gov (United States)

    Kukona, Anuenue; Tabor, Whitney

    2011-08-01

    The Visual World Paradigm (VWP) presents listeners with a challenging problem: They must integrate two disparate signals, the spoken language and the visual context, in support of action (e.g., complex movements of the eyes across a scene). We present Impulse Processing, a dynamical systems approach to incremental eye movements in the visual world that suggests a framework for integrating language, vision, and action generally. Our approach assumes that impulses driven by the language and the visual context impinge minutely on a dynamical landscape of attractors corresponding to the potential eye-movement behaviors of the system. We test three unique predictions of our approach in an empirical study in the VWP, and describe an implementation in an artificial neural network. We discuss the Impulse Processing framework in relation to other models of the VWP.

  9. The relationship between the stomatognathic system and body posture

    OpenAIRE

    Antonino Cuccia; Carola Caradonna

    2009-01-01

    In recent years, many researchers have investigated the various factors that can influence body posture: mood states, anxiety, head and neck positions, oral functions (respiration, swallowing), oculomotor and visual systems, and the inner ear. Recent studies indicate a role for trigeminal afferents on body posture, but this has not yet been demonstrated conclusively. The present study aims to review the papers that have shown a relationship between the stomatognathic system and body posture. ...

  10. Temperature-dependent variation in afferent nerve discharge in rat jejunum

    DEFF Research Database (Denmark)

    Gregersen, Hans; Yang, Jian; Zhao, Jingbo

    2015-01-01

    baseline discharge and on distension-induced afferent fibers innervating the rat jejunum. Methods: Multi-unit afferent activity was recorded in vitro from jejunum afferents from 9 Wistar rats. The segments were immersed in oxygenated Krebs solution varied between 21–43 °C. The mesenteric nerve bundle...

  11. Regenerating sprouts of axotomized cat muscle afferents express characteristic firing patterns to mechanical stimulation.

    Science.gov (United States)

    Johnson, R D; Munson, J B

    1991-12-01

    1. In cats, we studied the physiological properties of regenerating sprouts of muscle afferent fibers and compared them with sprouts from cutaneous afferent fibers. 2. Muscle nerves to the triceps surae and cutaneous sural nerves were axotomized in the popliteal fossa, and the proximal ends were inserted into nerve cuffs. Six days later, we recorded action potentials from single Groups I and II muscle and mostly Group II cutaneous afferents driven by mechanostimulation of the cuff. 3. Most muscle afferent sprouts (91%) had a regular slowly adapting discharge in response to sustained mechanical displacement of the cuff, particularly to sustained stretch stimuli, whereas most cutaneous afferents (92%) did not. Muscle afferents were more likely to have a spontaneous discharge and afterdischarge. 4. Group II muscle afferent sprouts had lower stretch thresholds and a higher incidence of spontaneous discharge compared with Group I fiber sprouts, whereas Group I fibers had a higher incidence of high-frequency afterdischarge to mechanical stimuli. 5. We conclude that, 6 days after axotomy, regenerating sprouts of muscle afferents, particularly Group II afferents, have become mechanosensitive in the absence of a receptor target and exhibit physiological properties similar to those found when innervating their native muscle but significantly different from sprouts of cutaneous afferents. Expression of these native muscle afferent firing patterns after the inappropriate reinnervation of hairy skin may be due to inherent properties of the muscle afferent fiber.

  12. DMPD: Afferent pathways of pyrogen signaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 9917870 Afferent pathways of pyrogen signaling. Blatteis CM, Sehic E, Li S. Ann N Y... Acad Sci. 1998 Sep 29;856:95-107. (.png) (.svg) (.html) (.csml) Show Afferent pathways of pyrogen signaling.... PubmedID 9917870 Title Afferent pathways of pyrogen signaling. Authors Blatteis CM, Sehic E, Li S. Publica

  13. A Dynamic Visualization Environment For The Design And Evaluation Of Automatic Vehicle Control Systems

    OpenAIRE

    Xu, Z.

    1995-01-01

    This document presents Dynamic Visualization, a project associated with the California PATH Program. The objective of the project is to develop a software which can animate automated highways, visualize the dynamics of automatic vehicles, and help the design and evaluation of automatic vehicle systems. This report summarizes the accomplishments of the project, describes the functions of the developed software, and provides an explanation of how to use the software.

  14. An interactive wireless communication system for visually impaired people using city bus transport.

    Science.gov (United States)

    Wang, Hsiao-Lan; Chen, Ya-Ping; Rau, Chi-Lun; Yu, Chung-Huang

    2014-04-25

    Visually impaired people have difficulty accessing information about public transportation systems. Several systems have been developed for assisting visually impaired and blind people to use the city bus. Most systems provide only one-way communication and require high-cost and complex equipment. The purpose of this study is to reduce the difficulties faced by visually impaired people when taking city buses, using an interactive wireless communication system. The system comprised a user module and a bus module to establish a direct one-to-one connection. When the user inputs 4-digit numbers, the user module immediately sends out the information. If the bus module receives the matched bus number, it buzzes and the warning LED flashes to notify the bus driver that someone is waiting to board on the bus. User tests were conducted by two visually impaired people in a simulated vehicle and a city bus. The success rate of interactive wireless communication, recognizing the arrival of the bus and boarding the correct bus reached 100% in all of the tests. The interactive wireless communication aid system is a valid and low-cost device for assisting visually impaired people to use city buses.

  15. Design and Implementation of Visualized Workflow Modeling System Based on B/S Structure

    Institute of Scientific and Technical Information of China (English)

    WANG Jian; LI wei-li

    2007-01-01

    According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications of WfMC and the workflow process definition meta-modei. The design for system structure is presented in detail, and the key technologies for system implementation are also introduced. Additionally, an example is illustrated to demonstrate the validity of system.

  16. Design and implementation of visualization methods for the CHANGES Spatial Decision Support System

    Science.gov (United States)

    Cristal, Irina; van Westen, Cees; Bakker, Wim; Greiving, Stefan

    2014-05-01

    The CHANGES Spatial Decision Support System (SDSS) is a web-based system aimed for risk assessment and the evaluation of optimal risk reduction alternatives at local level as a decision support tool in long-term natural risk management. The SDSS use multidimensional information, integrating thematic, spatial, temporal and documentary data. The role of visualization in this context becomes of vital importance for efficiently representing each dimension. This multidimensional aspect of the required for the system risk information, combined with the diversity of the end-users imposes the use of sophisticated visualization methods and tools. The key goal of the present work is to exploit efficiently the large amount of data in relation to the needs of the end-user, utilizing proper visualization techniques. Three main tasks have been accomplished for this purpose: categorization of the end-users, the definition of system's modules and the data definition. The graphical representation of the data and the visualization tools were designed to be relevant to the data type and the purpose of the analysis. Depending on the end-users category, each user should have access to different modules of the system and thus, to the proper visualization environment. The technologies used for the development of the visualization component combine the latest and most innovative open source JavaScript frameworks, such as OpenLayers 2.13.1, ExtJS 4 and GeoExt 2. Moreover, the model-view-controller (MVC) pattern is used in order to ensure flexibility of the system at the implementation level. Using the above technologies, the visualization techniques implemented so far offer interactive map navigation, querying and comparison tools. The map comparison tools are of great importance within the SDSS and include the following: swiping tool for comparison of different data of the same location; raster subtraction for comparison of the same phenomena varying in time; linked views for comparison

  17. Regulating critical period plasticity: insight from the visual system to fear circuitry for therapeutic interventions.

    Science.gov (United States)

    Nabel, Elisa M; Morishita, Hirofumi

    2013-01-01

    Early temporary windows of heightened brain plasticity called critical periods developmentally sculpt neural circuits and contribute to adult behavior. Regulatory mechanisms of visual cortex development - the preeminent model of experience-dependent critical period plasticity-actively limit adult plasticity and have proved fruitful therapeutic targets to reopen plasticity and rewire faulty visual system connections later in life. Interestingly, these molecular mechanisms have been implicated in the regulation of plasticity in other functions beyond vision. Applying mechanistic understandings of critical period plasticity in the visual cortex to fear circuitry may provide a conceptual framework for developing novel therapeutic tools to mitigate aberrant fear responses in post traumatic stress disorder. In this review, we turn to the model of experience-dependent visual plasticity to provide novel insights for the mechanisms regulating plasticity in the fear system. Fear circuitry, particularly fear memory erasure, also undergoes age-related changes in experience-dependent plasticity. We consider the contributions of molecular brakes that halt visual critical period plasticity to circuitry underlying fear memory erasure. A major molecular brake in the visual cortex, perineuronal net formation, recently has been identified in the development of fear systems that are resilient to fear memory erasure. The roles of other molecular brakes, myelin-related Nogo receptor signaling and Lynx family proteins - endogenous inhibitors for nicotinic acetylcholine receptor, are explored in the context of fear memory plasticity. Such fear plasticity regulators, including epigenetic effects, provide promising targets for therapeutic interventions.

  18. Regulating Critical Period Plasticity: Insight from the Visual System to Fear Circuitry for Therapeutic Interventions

    Directory of Open Access Journals (Sweden)

    Elisa M. Nabel

    2013-11-01

    Full Text Available Early temporary windows of heightened brain plasticity called critical periods developmentally sculpt neural circuits and contribute to adult behavior. Regulatory mechanisms of visual cortex development –the preeminent model of experience-dependent critical period plasticity- actively limit adult plasticity and have proved fruitful therapeutic targets to reopen plasticity and rewire faulty visual system connections later in life. Interestingly, these molecular mechanisms have been implicated in the regulation of plasticity in other functions beyond vision. Applying mechanistic understandings of critical period plasticity in the visual cortex to fear circuitry may provide a conceptual framework for developing novel therapeutic tools to mitigate aberrant fear responses in post traumatic stress disorder. In this review, we turn to the model of experience-dependent visual plasticity to provide novel insights for the mechanisms regulating plasticity in the fear system. Fear circuitry, particularly fear memory erasure, also undergoes age-related changes in experience-dependent plasticity. We consider the contributions of molecular brakes that halt visual critical period plasticity to circuitry underlying fear memory erasure. A major molecular brake in the visual cortex, perineuronal net formation, recently has been identified in the development of fear systems that are resilient to fear memory erasure. The roles of other molecular brakes, myelin-related Nogo receptor signaling and Lynx family proteins– endogenous inhibitors for nicotinic acetylcholine receptor, are explored in the context of fear memory plasticity. Such fear plasticity regulators, including epigenetic effects, provide promising targets for therapeutic interventions.

  19. A purely temporal transparency mechanism in the visual system.

    Science.gov (United States)

    Holcombe, A O

    2001-01-01

    I report evidence for a purely temporal perceptual transparency mechanism. Rapid alternation of two images in the same location can result in the simultaneous experience of both, accompanied by a sense of transparency. This is true even when the sum of the two images does not appear transparent, which suggests that the percept is not mediated by the static transparency processes. At slow rates, alternating gratings were experienced as successive. As the rate was increased, by 8 Hz observers experienced the gratings as simultaneous. The rapidly alternating gratings are apparently processed separately before being combined for awareness by a process that integrates over about 120 ms. A final experiment tested whether the common presentation time of different parts of an image in alternation with another would cause the parts to perceptually bind. Observers did not distinguish between a rapidly alternating intact grating display and one in which halves of the display were exchanged in time. In other words, temporal binding across space did not occur. The temporal transparency phenomenon, in addition to informing theories of transparency and the dynamics of visual processing, may also be useful for the creation of transparent displays for electronic devices.

  20. explorase: Multivariate Exploratory Analysis and Visualization for Systems Biology

    Directory of Open Access Journals (Sweden)

    Michael Lawrence

    2008-03-01

    Full Text Available The datasets being produced by high-throughput biological experiments, such as microarrays, have forced biologists to turn to sophisticated statistical analysis and visualization tools in order to understand their data. We address the particular need for an open-source exploratory data analysis tool that applies numerical methods in coordination with interactive graphics to the analysis of experimental data. The software package, known as explorase, provides a graphical user interface (GUI on top of the R platform for statistical computing and the GGobi software for multivariate interactive graphics. The GUI is designed for use by biologists, many of whom are unfamiliar with the R language. It displays metadata about experimental design and biological entities in tables that are sortable and filterable. There are menu shortcuts to the analysis methods implemented in R, including graphical interfaces to linear modeling tools. The GUI is linked to data plots in GGobi through a brush tool that simultaneously colors rows in the entity information table and points in the GGobi plots.

  1. DEVELOPMENT OF A GEOGRAPHIC VISUALIZATION AND COMMUNICATIONS SYSTEMS (GVCS) FOR MONITORING REMOTE VEHICLES

    Energy Technology Data Exchange (ETDEWEB)

    COLEMAN, P.; DUNCAN, M.; DURFEE, R.C.; GOELTZ, R; HARRISON, G.; HODGSON, M.E.; KOOK, M.; MCCLAIN, S.

    1998-03-30

    The purpose of this project is to integrate a variety of geographic information systems capabilities and telecommunication technologies for potential use in geographic network and visualization applications. The specific technical goals of the project were to design, develop, and simulate the components of an audio/visual geographic communications system to aid future real-time monitoring, mapping and managing of transport vehicles. The system components of this feasibility study are collectively referred to as a Geographic Visualization and Communications System (GVCS). State-of-the-art techniques will be used and developed to allow both the vehicle operator and network manager to monitor the location and surrounding environment of a transport vehicle during shipment.

  2. Age-related gene expression change of GABAergic system in visual cortex of rhesus macaque.

    Science.gov (United States)

    Liao, Chenghong; Han, Qian; Ma, Yuanye; Su, Bing

    2016-09-30

    Degradation of visual function is a common phenomenon during aging and likely mediated by change in the impaired central visual pathway. Treatment with GABA or its agonist could recover the ability of visual neurons in the primary visual cortex of senescent macaques. However, little is known about how GABAergic system change is related to the aged degradation of visual function in nonhuman primate. With the use of quantitative PCR method, we measured the expression change of 24 GABA related genes in the primary visual cortex (Brodmann's 17) of different age groups. In this study, both of mRNA and protein of glutamic acid decarboxylase (GAD65) were measured by real-time RT-PCR and Western blot, respectively. Results revealed that the level of GAD65 message was not significantly altered, but the proteins were significantly decreased in the aged monkey. As GAD65 plays an important role in GABA synthesis, the down-regulation of GAD65 protein was likely the key factor leading to the observed GABA reduction in the primary visual cortex of the aged macaques. In addition, 7 of 14 GABA receptor genes were up-regulated and one GABA receptor gene was significantly reduced during aging process even after Banjamini correction for multiple comparisons (Pvisual dysfunctions and most of GABA receptor genes induce a clear indication of compensatory effect for the reduced GABA release in the healthy aged monkey cortex.

  3. Design and Implementation of One Missile Visual Simulation System Based on OpenGL

    Institute of Scientific and Technical Information of China (English)

    GAO Ying; ZHANG Pu-zhao; PENG Yu-xin; HUANG Jian-guo

    2007-01-01

    The implementation of a missile's visual simulation system is explained that is developed with OpenGL(open graphic library) and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile's data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.

  4. VISUAL TEACHING TECHNOLOGY IN IT SYSTEMS FOR THE “MILLENNIAL GENERATION”

    Directory of Open Access Journals (Sweden)

    Robert Lis

    2015-11-01

    Full Text Available This publication presents the ongoing development of visual teaching technology in IT systems, which can be used for e-learning for the “Millennial Generation”. The analysis of different models of teaching making use of visual messages, leads to the conclusion that systems more advanced in VPN technologies possess substantial educational qualities. These systems include TightVPN, UltraVNC, OpenVPN, RealVNC or Radmin and ComodoUNITE as well as TeamViewer.

  5. Visual MRI grading system to evaluate atrophy of the supeaspinatus muscle

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Hyun Kyoung; Hong, Sung Hwan; Yoo, Hye Jin; Choi, Ja Young; Kim, Sae Hoon; Choi, Jung Ah; Kang, Heung Sik [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2014-08-15

    To investigate the interobserver reproducibility and diagnostic feasibility of a visual grading system for assessing atrophy of the supraspinatus muscle on magnetic resonance imaging (MRI). Three independent radiologists retrospectively evaluated the occupying ratio of the supraspinatus muscle in the supraspinatus fossa on 192 shoulder MRI examinations in 188 patients using a 3-point visual grading system (1, ≥ 60%; 2, 30-59%; 3, < 30%) on oblique sagittal T1-weighted images. The inter-reader agreement and the agreement with the reference standard (3-point grades according to absolute occupying ratio values quantitatively measured by directly contouring the muscles on MRI) were analyzed using weighted kappa. The visual grading was applied by a single reader to a group of 100 consecutive patients who had undergone rotator cuff repair to retrospectively determine the association between the visual grades at preoperative state and postsurgical occurrences of retear. The inter-reader weighted kappa value for the visual grading was 0.74 when averaged across three reader pairs (0.70-0.77 for individual reader pairs). The weighted kappa value between the visual grading and the reference standard ranged from 0.75 to 0.83. There was a significant difference in retear rates of the rotator cuff between the 3 visual grades of supraspinatus muscle atrophy on MRI in univariable analysis (p < 0.001), but not in multivariable analysis (p = 0.026). The 3-point visual grading system may be a feasible method to assess the severity of supraspinatus muscle atrophy on MRI and assist in the clinical management of patients with rotator cuff tear.

  6. The µ-opioid system promotes visual attention to faces and eyes.

    Science.gov (United States)

    Chelnokova, Olga; Laeng, Bruno; Løseth, Guro; Eikemo, Marie; Willoch, Frode; Leknes, Siri

    2016-12-01

    Paying attention to others' faces and eyes is a cornerstone of human social behavior. The µ-opioid receptor (MOR) system, central to social reward-processing in rodents and primates, has been proposed to mediate the capacity for affiliative reward in humans. We assessed the role of the human MOR system in visual exploration of faces and eyes of conspecifics. Thirty healthy males received a novel, bidirectional battery of psychopharmacological treatment (an MOR agonist, a non-selective opioid antagonist, or placebo, on three separate days). Eye-movements were recorded while participants viewed facial photographs. We predicted that the MOR system would promote visual exploration of faces, and hypothesized that MOR agonism would increase, whereas antagonism decrease overt attention to the information-rich eye region. The expected linear effect of MOR manipulation on visual attention to the stimuli was observed, such that MOR agonism increased while antagonism decreased visual exploration of faces and overt attention to the eyes. The observed effects suggest that the human MOR system promotes overt visual attention to socially significant cues, in line with theories linking reward value to gaze control and target selection. Enhanced attention to others' faces and eyes represents a putative behavioral mechanism through which the human MOR system promotes social interest.

  7. Visualization of Processes in Self-Learning Systems

    NARCIS (Netherlands)

    Peters, Gabriele; Bunte, Kerstin; Strickert, Marc; Biehl, Michael; Villmann, Thomas

    2012-01-01

    One aspect of self-organizing systems is their desired ability to be self-learning, i.e., to be able to adapt dynamically to conditions in their environment. This quality is awkward especially if it comes to applications in security or safety-sensitive areas. Here a step towards more trustful system

  8. Framing futures: visualizing on social-ecological systems change

    NARCIS (Netherlands)

    Vervoort, J.M.

    2011-01-01

    An appreciation of the complexity and uncertainty that characterizes linked human and natural systems - or social-ecological systems - has proliferated throughout the sciences in recent decades. However, dominant societal images, mental models and discourses frame the complexity of social-ecological

  9. Framing futures: visualizing on social-ecological systems change

    NARCIS (Netherlands)

    Vervoort, J.M.

    2011-01-01

    An appreciation of the complexity and uncertainty that characterizes linked human and natural systems - or social-ecological systems - has proliferated throughout the sciences in recent decades. However, dominant societal images, mental models and discourses frame the complexity of social-ecological

  10. Diverse firing properties and Aβ-, Aδ-, and C-afferent inputs of small local circuit neurons in spinal lamina I.

    Science.gov (United States)

    Fernandes, Elisabete C; Luz, Liliana L; Mytakhir, Oleh; Lukoyanov, Nikolai V; Szucs, Peter; Safronov, Boris V

    2016-02-01

    Spinal lamina I is a key element of the pain processing system, which integrates primary afferent input and relays it to supraspinal areas. More than 90% of neurons in this layer are local circuit neurons, whose role in the signal processing is poorly understood. We performed whole-cell recordings in a spinal cord preparation with attached dorsal roots to examine morphological features and physiological properties of small local circuit neurons (n = 47) in lamina I. Cells successfully filled with biocytin (n = 17) had fusiform (n = 10), flattened (n = 4), and multipolar (n = 3) somatodendritic morphology; their axons branched extensively and terminated in laminae I-III. Intrinsic firing properties were diverse; in addition to standard tonic (n = 16), adapting (n = 7), and delayed (n = 6) patterns, small local circuit neurons also generated rhythmic discharges (n = 6) and plateau potentials (n = 10), the latter were suppressed by the L-type Ca(2+)-channel blocker nifedipine. The neurons received monosynaptic inputs from Aδ and C afferents and could generate bursts of spikes on the root stimulation. In addition, we identified lamina I neurons (n = 7) with direct inputs from the low-threshold Aβ afferents, which could be picked up by ventral dendrites protruding to lamina III. Stimulation of afferents also evoked a disynaptic inhibition of neurons. Thus, small local circuit neurons exhibit diverse firing properties, can generate rhythmic discharges and plateau potentials, and their dendrites extending into several laminae allow broad integration of Aβ-, Aδ-, and C-afferent inputs. These properties are required for processing diverse modalities of nociceptive inputs in lamina I and may underlie spinal sensitization to pain.

  11. Design and implementation of visual inspection system handed in tokamak flexible in-vessel robot

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hesheng; Xu, Lifei [Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China (China); Chen, Weidong, E-mail: wdchen@sjtu.edu.cn [Department of Automation, Shanghai Jiao Tong University, Shanghai 200240 (China); Key Laboratory of System Control and Information Processing, Ministry of Education of China (China)

    2016-05-15

    In-vessel viewing system (IVVS) is a fundamental tool among the remote handling systems for ITER, which is used to providing information on the status of the in-vessel components. The basic functional requirement of in-vessel visual inspection system is to perform a fast intervention with adequate optical resolution. In this paper, we present the software and hardware solution, which is designed and implemented for tokamak in-vessel viewing system that installed on end-effector of flexible in-vessel robot working under vacuum and high temperature. The characteristic of our in-vessel viewing system consists of two parts: binocular heterogeneous vision inspection tool and first wall scene emersion based augment virtuality. The former protected with water-cooled shield is designed to satisfy the basic functional requirement of visual inspection system, which has the capacity of large field of view and high-resolution for detection precision. The latter, achieved by overlaying first wall tiles images onto virtual first wall scene model in 3D virtual reality simulation system, is designed for convenient, intuitive and realistic-looking visual inspection instead of viewing the status of first wall only by real-time monitoring or off-line images sequences. We present the modular division of system, each of them in smaller detail, and go through some of the design choices according to requirements of in-vessel visual inspection task.

  12. A Survey of Successful Evaluations of Program Visualization and Algorithm Animation Systems

    Science.gov (United States)

    Urquiza-Fuentes, Jaime; Velazquez-Iturbide, J. Angel

    2009-01-01

    This article reviews successful educational experiences in using program and algorithm visualizations (PAVs). First, we survey a total of 18 PAV systems that were subject to 33 evaluations. We found that half of the systems have only been tested for usability, and those were shallow inspections. The rest were evaluated with respect to their…

  13. A Survey of Successful Evaluations of Program Visualization and Algorithm Animation Systems

    Science.gov (United States)

    Urquiza-Fuentes, Jaime; Velazquez-Iturbide, J. Angel

    2009-01-01

    This article reviews successful educational experiences in using program and algorithm visualizations (PAVs). First, we survey a total of 18 PAV systems that were subject to 33 evaluations. We found that half of the systems have only been tested for usability, and those were shallow inspections. The rest were evaluated with respect to their…

  14. Finding and recognising objects in natural scenes: complementary computations in the dorsal and ventral visual systems

    Directory of Open Access Journals (Sweden)

    Edmund eRolls

    2014-08-01

    Full Text Available Searching for and recognising objects in complex natural scenes is implemented by multiple saccades until the eyes reach within the reduced receptive field sizes of inferior temporal cortex (IT neurons. We analyse and model how the dorsal and ventral visual streams both contribute to this. Saliency detection in the dorsal visual system including area LIP is modelled by graph-based visual saliency, and allows the eyes to fixate potential objects within several degrees. Visual information at the fixated location subtending approximately 9 degrees corresponding to the receptive fields of IT neurons is then passed through a four layer hierarchical model of the ventral cortical visual system, VisNet. We show that VisNet can be trained using a synaptic modification rule with a short-term memory trace of recent neuronal activity to capture both the required view and translation invariances to allow in the model approximately 90% correct object recognition for 4 objects shown in any view across a range of 135 degrees anywhere in a scene.The model was able to generalize correctly within the four trained views and the 25 trained translations.This approach analyses the principles by which complementary computations in the dorsal and ventral visual cortical streams enable objects to be located and recognised in complex natural scenes.

  15. A navigation system for the visually impaired using colored navigation lines and RFID tags.

    Science.gov (United States)

    Seto, First Tatsuya

    2009-01-01

    In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. Our developed instrument consists of a navigation system and a map information system. These systems are installed on a white cane. Our navigation system can follow a colored navigation line that is set on the floor. In this system, a color sensor installed on the tip of a white cane senses the colored navigation line, and the system informs the visually impaired that he/she is walking along the navigation line by vibration. The color recognition system is controlled by a one-chip microprocessor and this system can discriminate 6 colored navigation lines. RFID tags and a receiver for these tags are used in the map information system. The RFID tags and the RFID tag receiver are also installed on a white cane. The receiver receives tag information and notifies map information to the user by mp3 formatted pre-recorded voice. Three normal subjects who were blindfolded with an eye mask were tested with this system. All of them were able to walk along the navigation line. The performance of the map information system was good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

  16. Characterizing the effects of feature salience and top-down attention in the early visual system.

    Science.gov (United States)

    Poltoratski, Sonia; Ling, Sam; McCormack, Devin; Tong, Frank

    2017-04-05

    The visual system employs a sophisticated balance of attentional mechanisms: salient stimuli are prioritized for visual processing, yet observers can also ignore such stimuli when their goals require directing attention elsewhere. A powerful determinant of visual salience is local feature contrast: if a local region differs from its immediate surround along one or more feature dimensions, it will appear more salient. Here, we used high-resolution fMRI at 7T to characterize the modulatory effects of bottom-up salience and top-down voluntary attention within multiple sites along the early visual pathway, including visual areas V1-V4 and the lateral geniculate nucleus (LGN). Observers viewed arrays of spatially distributed gratings, where one of the gratings immediately to the left or right of fixation differed from all other items in orientation or motion direction, making it salient. To investigate the effects of directed attention, observers were cued to attend to the grating to the left or right of fixation, which was either salient or non-salient. Results revealed reliable additive effects of top-down attention and stimulus-driven salience throughout visual areas V1-hV4. In comparison, the LGN exhibited significant attentional enhancement but was not reliably modulated by orientation- or motion-defined salience. Our findings indicate that top-down effects of spatial attention can influence visual processing at the earliest possible site along the visual pathway, including the LGN, while the processing of orientation- and motion-driven salience primarily involves feature-selective interactions that take place in early cortical visual areas.

  17. Visual perceptual issues of the integrated helmet and display sighting system (IHADSS): four expert perspectives

    Science.gov (United States)

    Rash, Clarence E.; Heinecke, Kevin; Francis, Gregory; Hiatt, Keith L.

    2008-04-01

    The Integrated Helmet and Display Sighting System (IHADSS) helmet-mounted display (HMD) has been flown for over a quarter of a century on the U.S. Army's AH-64 Apache Attack Helicopter. The aircraft's successful deployment in both peacetime and combat has validated the original design concept for the IHADSS HMD. During its 1970s development phase, a number of design issues were identified as having the potential of introducing visual perception problems for aviators. These issues include monocular design, monochromatic imagery, reduced field-of-view (FOV), sensor spectrum, reduced resolution (effective visual acuity), and displaced visual input eye point. From their diverse perspectives, a panel of four experts - an HMD researcher, a cognitive psychologist, a flight surgeon, and a veteran AH-64 aviator - discuss the impact of the design issues on visual perception and related performance.

  18. Better-Than-Visual Technologies for Next Generation Air Transportation System Terminal Maneuvering Area Operations

    Science.gov (United States)

    Prinzel, Lawrence J., III; Bailey, Randall E.; Shelton, Kevin J.; Jones, Denise R.; Kramer, Lynda J.; Arthur, Jarvis J., III; Williams, Steve P.; Barmore, Bryan E.; Ellis, Kyle E.; Rehfeld, Sherri A.

    2011-01-01

    A consortium of industry, academia and government agencies are devising new concepts for future U.S. aviation operations under the Next Generation Air Transportation System (NextGen). Many key capabilities are being identified to enable NextGen, including the concept of Equivalent Visual Operations (EVO) replicating the capacity and safety of today's visual flight rules (VFR) in all-weather conditions. NASA is striving to develop the technologies and knowledge to enable EVO and to extend EVO towards a Better-Than-Visual (BTV) operational concept. The BTV operational concept uses an electronic means to provide sufficient visual references of the external world and other required flight references on flight deck displays that enable VFR-like operational tempos and maintain and improve the safety of VFR while using VFR-like procedures in all-weather conditions. NASA Langley Research Center (LaRC) research on technologies to enable the concept of BTV is described.

  19. A Global System for Transportation Simulation and Visualization in Emergency Evacuation Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei [ORNL; Liu, Cheng [ORNL; Thomas, Neil [ORNL; Bhaduri, Budhendra L [ORNL; Han, Lee [University of Tennessee, Knoxville (UTK)

    2015-01-01

    Simulation-based studies are frequently used for evacuation planning and decision making processes. Given the transportation systems complexity and data availability, most evacuation simulation models focus on certain geographic areas. With routine improvement of OpenStreetMap road networks and LandScanTM global population distribution data, we present WWEE, a uniform system for world-wide emergency evacuation simulations. WWEE uses unified data structure for simulation inputs. It also integrates a super-node trip distribution model as the default simulation parameter to improve the system computational performance. Two levels of visualization tools are implemented for evacuation performance analysis, including link-based macroscopic visualization and vehicle-based microscopic visualization. For left-hand and right-hand traffic patterns in different countries, the authors propose a mirror technique to experiment with both scenarios without significantly changing traffic simulation models. Ten cities in US, Europe, Middle East, and Asia are modeled for demonstration. With default traffic simulation models for fast and easy-to-use evacuation estimation and visualization, WWEE also retains the capability of interactive operation for users to adopt customized traffic simulation models. For the first time, WWEE provides a unified platform for global evacuation researchers to estimate and visualize their strategies performance of transportation systems under evacuation scenarios.

  20. Brief report: a hypothetical construct based on limited data visual system recovery after refractive surgery.

    Science.gov (United States)

    Lattimore, Morris R

    2015-03-01

    Laser refractive surgery, involving the computer-controlled application of a 193-nm beam of excimer laser "light," is utilized to resculpt the central cornea, thus reducing its apical thickness. On casual inspection, this simple matter of removing or excising a specific amount of central corneal avascular tissue is a smooth, seamless alteration with few apparent secondary issues or sequelae. Normal postoperative recovery is typically gauged by the recovery of high-contrast visual acuity to the same (or better) degree as was previously obtained with a spectacle correction. However, although this is an acceptable means of determining operative success, it is not indicative of the complex challenges imposed upon the neurosensory system. The secondarily imposed strain upon the visual system, regarding the return to its pre-existing visual line-of-sight organization occurs only by bringing multiple adaptations into subtle and seamless play. This process is initiated and completed in a relatively short time period, such that most patients (but not all) are not even marginally aware of the challenges imposed to the visual system. This article is meant to probe those system challenges, serving to highlight this postoperative plasticity, seeking to gain a broader understanding and appreciation of the perceptual range of the visual recovery process.

  1. Indoor Navigation System based on Passive RFID Transponder with Digital Compass for Visually Impaired People

    Directory of Open Access Journals (Sweden)

    A. M. Kassim

    2016-02-01

    Full Text Available Conventionally, visually impaired people using white cane or guide dog for traveling to desired destination. However, they could not identify their surround easily. Hence, this paper describes the development of navigation system which is applied to guide the visually impaired people at an indoor environment. To provide an efficient and user-friendly navigation tools, a navigation device is developed by using passive radio frequency identification (RFID transponders which are mounted on the floor such as on tactile paving to build such as RFID networks. The developed navigation system is equipped with a digital compass to facilitate the visually impaired people to walk properly at right direction especially when turning process. The idea of positioning and localization with the digital compass and direction guiding through voice commands is implemented in this system. Some experiments also done which is focused on the calibration of the digital compass and relocates the visually impaired people back to the right route if they are out of the direction. Besides, a comparison between two subjects which are human and a mobile robot is made to check the validity of the developed navigation system. As the result, the traveling speed of human and mobile robot is obtained from the experiment. This project is beneficial to visually impaired people because the navigation device designed with voice commands will help them to have a better experience, safer and comfortable travel.

  2. Retinal afferents synapse with relay cells targeting the middle temporal area in the pulvinar and lateral geniculate nuclei

    Directory of Open Access Journals (Sweden)

    Claire E Warner

    2010-02-01

    Full Text Available Considerable debate continues regarding thalamic inputs to the middle temporal area (MT of the visual cortex that bypass the primary visual cortex (V1 and the role they might have in the residual visual capability following a lesion of V1. Two specific retinothalamic projections to area MT have been speculated to relay through the medial portion of the inferior pulvinar nucleus (PIm and the koniocellular layers of the dorsal lateral geniculate nucleus (LGN. Although a number of studies have demonstrated retinal inputs to regions of the thalamus where relays to area MT have been observed, the relationship between the retinal terminals and area MT relay cells has not been established. Here we examined direct retino-recipient regions of the marmoset monkey (Callithrix jacchus pulvinar nucleus and the LGN following binocular injections of anterograde tracer, as well as area MT relay cells in these nuclei by injection of retrograde tracer into area MT. Retinal afferents were shown to synapse with area MT relay cells as demonstrated by colocalization with the presynaptic vesicle membrane protein synaptophysin. We also established the presence of direct synapes of retinal afferents on area MT relay cells within the PIm, as well as the koniocellular K1 and K3 layers of the LGN, thereby corroborating the existence of two disynaptic pathways from the retina to area MT that bypass V1.

  3. Efficient visual system processing of spatial and luminance statistics in representational and non-representational art

    Science.gov (United States)

    Graham, Daniel J.; Friedenberg, Jay D.; Rockmore, Daniel N.

    2009-02-01

    An emerging body of research suggests that artists consistently seek modes of representation that are efficiently processed by the human visual system, and that these shared properties could leave statistical signatures. In earlier work, we showed evidence that perceived similarity of representational art could be predicted using intensity statistics to which the early visual system is attuned, though semantic content was also found to be an important factor. Here we report two studies that examine the visual perception of similarity. We test a collection of non-representational art, which we argue possesses useful statistical and semantic properties, in terms of the relationship between image statistics and basic perceptual responses. We find two simple statistics-both expressed as single values-that predict nearly a third of the overall variance in similarity judgments of abstract art. An efficient visual system could make a quick and reasonable guess as to the relationship of a given image to others (i.e., its context) by extracting these basic statistics early in the visual stream, and this may hold for natural scenes as well as art. But a major component of many types of art is representational content. In a second study, we present findings related to efficient representation of natural scene luminances in landscapes by a well-known painter. We show empirically that elements of contemporary approaches to high-dynamic range tone-mapping-which are themselves deeply rooted in an understanding of early visual system coding-are present in the way Vincent Van Gogh transforms scene luminances into painting luminances. We argue that global tone mapping functions are a useful descriptor of an artist's perceptual goals with respect to global illumination and we present evidence that mapping the scene to a painting with different implied lighting properties produces a less efficient mapping. Together, these studies suggest that statistical regularities in art can shed

  4. Study on algorithm of dynamic uncalibrated eye-in-hand visual servoing system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Currently, most visual servoing system must be calibrated, while it is impossible to calibrate cameras and robot models precisely in industrial practice, so a novel dynamic uncalibrated eye-in-hand visual servoing system of tracking a moving target is proposed. The method does not require calibration of camera and robot kinematic models. Vision guided algorithm for tracking dynamic image is developed through minimizing nonlinear objective function. For the large residual has not been approximated in dynamic environment and the change of composite image Jacobian with time increment has not been computed in visual servoing system now,large residuals are dynamic approximated and the change of composite image Jacobian at each iterative step is computed.Simulation results demonstrate the validity of these approaches.

  5. How do Interruptions Impact Nurses’ Visual Scanning Patterns When Using Barcode Medication Administration Systems?

    Science.gov (United States)

    He, Ze; Marquard, Jenna L.; Henneman, Philip L.

    2014-01-01

    While barcode medication administration (BCMA) systems have the potential to reduce medication errors, they may introduce errors, side effects, and hazards into the medication administration process. Studies of BCMA systems should therefore consider the interrelated nature of health information technology (IT) use and sociotechnical systems. We aimed to understand how the introduction of interruptions into the BCMA process impacts nurses’ visual scanning patterns, a proxy for one component of cognitive processing. We used an eye tracker to record nurses’ visual scanning patterns while administering a medication using BCMA. Nurses either performed the BCMA process in a controlled setting with no interruptions (n=25) or in a real clinical setting with interruptions (n=21). By comparing the visual scanning patterns between the two groups, we found that nurses in the interruptive environment identified less task-related information in a given period of time, and engaged in more information searching than information processing. PMID:25954449

  6. How do interruptions impact nurses' visual scanning patterns when using barcode medication administration systems?

    Science.gov (United States)

    He, Ze; Marquard, Jenna L; Henneman, Philip L

    2014-01-01

    While barcode medication administration (BCMA) systems have the potential to reduce medication errors, they may introduce errors, side effects, and hazards into the medication administration process. Studies of BCMA systems should therefore consider the interrelated nature of health information technology (IT) use and sociotechnical systems. We aimed to understand how the introduction of interruptions into the BCMA process impacts nurses' visual scanning patterns, a proxy for one component of cognitive processing. We used an eye tracker to record nurses' visual scanning patterns while administering a medication using BCMA. Nurses either performed the BCMA process in a controlled setting with no interruptions (n=25) or in a real clinical setting with interruptions (n=21). By comparing the visual scanning patterns between the two groups, we found that nurses in the interruptive environment identified less task-related information in a given period of time, and engaged in more information searching than information processing.

  7. Development of 4D jaw movement visualization system for dental diagnosis support

    Science.gov (United States)

    Aoki, Yoshimitsu; Terajima, Masahiko; Nakasima, Akihiko

    2004-10-01

    A person with an asymmetric morphology of maxillofacial skeleton reportedly possesses an asymmetric jaw function and the risk to express temporomandibular disorder is high. A comprehensive analysis from the point of view of both the morphology and the function such as maxillofacial or temporomandibular joint morphology, dental occlusion, and features of mandibular movement pathways is essential. In this study, the 4D jaw movement visualization system was developed to visually understand the characteristic jaw movement, 3D maxillofacial skeleton structure, and the alignment of the upper and lower teeth of a patient. For this purpose, the 3D reconstructed images of the cranial and mandibular bones, obtained by computed tomography, were measured using a non-contact 3D measuring device, and the obtained morphological images of teeth model were integrated and activated on the 6 DOF jaw movement data. This system was experimentally applied and visualized in a jaw deformity patient and its usability as a clinical diagnostic support system was verified.

  8. Interactive analysis and visualization of massive earth system models using VAPOR

    Science.gov (United States)

    Norton, Alan; Clyne, John

    2013-04-01

    Recent trends in earth system modeling are leading to a dramatic increase in the size of simulation outputs; however current visualization and analysis capabilities do not readily scale with the increased simulation size. VAPOR is a visualization and analysis package that was designed to enable interactive visualization and analysis of these large datasets, using a wavelet-based multiscale data model. VAPOR runs on Mac, Windows and Linux desktops, exploiting the power of modern graphics cards. VAPOR includes several features to facilitate interactive analysis of earth system data, such as built-in support for Python/NumPy scripting, streamlines, particle tracing and geo-referencing. In this presentation the capabilities of VAPOR will be described and applied to various earth system models. We shall show how to use VAPOR to interactively browse and analyze these large datasets, such as the results of the POP ocean model and the WRF-ARW weather model.

  9. Effective solutions to a global 3D visual system in networking environments

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Liqiang; ZHANG; Yan; YANG; Chongjun; LIU; Suhong; R

    2005-01-01

    The development of Web-based global 3D visual system has made progresses. However, there exist few mature and effective ways for managing, transmitting and visualizing massive spatial data. Based on the related work, the paper illustrates the ellipsoidal quadtree technique for rapid access multi-scale and multiple level geographical data, integrates the streaming with level-of-detail rendering method for transmitting the data on the network, and implements large-scale terrain surface simplification using M-band wavelet transforms and multiresolution triangulations. We fulfil a web-based global terrain visual system using COM components on the basis of the above techniques. The system has a good prospect in the military simulation and city plans.

  10. On Assisting a Visual-Facial Affect Recognition System with Keyboard-Stroke Pattern Information

    Science.gov (United States)

    Stathopoulou, I.-O.; Alepis, E.; Tsihrintzis, G. A.; Virvou, M.

    Towards realizing a multimodal affect recognition system, we are considering the advantages of assisting a visual-facial expression recognition system with keyboard-stroke pattern information. Our work is based on the assumption that the visual-facial and keyboard modalities are complementary to each other and that their combination can significantly improve the accuracy in affective user models. Specifically, we present and discuss the development and evaluation process of two corresponding affect recognition subsystems, with emphasis on the recognition of 6 basic emotional states, namely happiness, sadness, surprise, anger and disgust as well as the emotion-less state which we refer to as neutral. We find that emotion recognition by the visual-facial modality can be aided greatly by keyboard-stroke pattern information and the combination of the two modalities can lead to better results towards building a multimodal affect recognition system.

  11. Vagal afferents are essential for maximal resection-induced intestinal adaptive growth in orally fed rats.

    Science.gov (United States)

    Nelson, David W; Liu, Xiaowen; Holst, Jens J; Raybould, Helen E; Ney, Denise M

    2006-11-01

    Small bowel resection stimulates intestinal adaptive growth by a neuroendocrine process thought to involve both sympathetic and parasympathetic innervation and enterotrophic hormones such as glucagon-like peptide-2 (GLP-2). We investigated whether capsaicin-sensitive vagal afferent neurons are essential for maximal resection-induced intestinal growth. Rats received systemic or perivagal capsaicin or ganglionectomy before 70% midjejunoileal resection or transection and were fed orally or by total parenteral nutrition (TPN) for 7 days after surgery. Growth of residual bowel was assessed by changes in mucosal mass, protein, DNA, and histology. Both systemic and perivagal capsaicin significantly attenuated by 48-100% resection-induced increases in ileal mucosal mass, protein, and DNA in rats fed orally. Villus height was significantly reduced in resected rats given capsaicin compared with vehicle. Sucrase specific activity in jejunal mucosa was not significantly different; ileal mucosal sucrase specific activity was significantly increased by resection in capsaicin-treated rats. Capsaicin did not alter the 57% increase in ileal proglucagon mRNA or the 150% increase in plasma concentration of bioactive GLP-2 resulting from resection in orally fed rats. Ablation of spinal/splanchnic innervation by ganglionectomy failed to attenuate resection-induced adaptive growth. In TPN rats, capsaicin did not attenuate resection-induced mucosal growth. We conclude that vagal afferents are not essential for GLP-2 secretion when the ileum has direct contact with luminal nutrients after resection. In summary, vagal afferent neurons are essential for maximal resection-induced intestinal adaptation through a mechanism that appears to involve stimulation by luminal nutrients.

  12. A Low-Cost Audio Prescription Labeling System Using RFID for Thai Visually-Impaired People.

    Science.gov (United States)

    Lertwiriyaprapa, Titipong; Fakkheow, Pirapong

    2015-01-01

    This research aims to develop a low-cost audio prescription labeling (APL) system for visually-impaired people by using the RFID system. The developed APL system includes the APL machine and APL software. The APL machine is for visually-impaired people while APL software allows caregivers to record all important information into the APL machine. The main objective of the development of the APL machine is to reduce costs and size by designing all of the electronic devices to fit into one print circuit board. Also, it is designed so that it is easy to use and can become an electronic aid for daily living. The developed APL software is based on Java and MySQL, both of which can operate on various operating platforms and are easy to develop as commercial software. The developed APL system was first evaluated by 5 experts. The APL system was also evaluated by 50 actual visually-impaired people (30 elders and 20 blind individuals) and 20 caregivers, pharmacists and nurses. After using the APL system, evaluations were carried out, and it can be concluded from the evaluation results that this proposed APL system can be effectively used for helping visually-impaired people in terms of self-medication.

  13. The modulation of visual and task characteristics of a writing system on hemispheric lateralization in visual word recognition-a computational exploration.

    Science.gov (United States)

    Hsiao, Janet H; Lam, Sze Man

    2013-07-01

    Through computational modeling, here we examine whether visual and task characteristics of writing systems alone can account for lateralization differences in visual word recognition between different languages without assuming influence from left hemisphere (LH) lateralized language processes. We apply a hemispheric processing model of face recognition to visual word recognition; the model implements a theory of hemispheric asymmetry in perception that posits low spatial frequency biases in the right hemisphere and high spatial frequency (HSF) biases in the LH. We show two factors that can influence lateralization: (a) Visual similarity among words: The more similar the words in the lexicon look visually, the more HSF/LH processing is required to distinguish them, and (b) Requirement to decompose words into graphemes for grapheme-phoneme mapping: Alphabetic reading (involving grapheme-phoneme conversion) requires more HSF/LH processing than logographic reading (no grapheme-phoneme mapping). These factors may explain the difference in lateralization between English and Chinese orthographic processing.

  14. Data Management System Reuse for Visualization of JPL's SMAP Project

    Science.gov (United States)

    Alarcon, C.; Huang, T.; Roberts, J. T.; Rodriguez, J. D.; Quach, N. T.; De Cesare, C.; Hall, J. R.

    2015-12-01

    The Imagery Exchange (TIE) is a scalable and efficient imagery data management system that powers the WMS web server OnEarth. Designed and developed at the Jet Propulsion Laboratory (JPL), TIE's primary purpose was to power the NASA's Global Imagery Browse Services (GIBS), a system that provides full resolution imagery from a broad set of Earth science disciplines to the public. The SMAP project at JPL had just about all of its requirements met with GIBS but required very project-specific behavior and automation for the Cal-Val phase of the project. Thanks to the extendable design of TIE (already an extension of JPL's Horizon framework) and Amazon's GovCloud services, we were able to meet the needs of the project without any rewrite of the system while significantly expanding the capabilities of an already robust system through well modularized feature additions. In this presentation, we will talk about the efforts made to re-use the already developed data system TIE for SMAP with minimal turn around. Leveraging cloud resources and standard interfaces, we were able to satisfy new project requirements in a very short amount of time.

  15. Albinism: Particular attention to the ocular motor system

    Directory of Open Access Journals (Sweden)

    Richard W Hertle

    2013-01-01

    Full Text Available The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.

  16. Albinism: particular attention to the ocular motor system.

    Science.gov (United States)

    Hertle, Richard W

    2013-01-01

    The purpose of this report is to summarize an understanding of the ocular motor system in patients with albinism. Other than the association of vertical eccentric gaze null positions and asymmetric, (a) periodic alternating nystagmus in a large percentage of patients, the ocular motor system in human albinism does not contain unique pathology, rather has "typical" types of infantile ocular oscillations and binocular disorders. Both the ocular motor and afferent visual system are affected to varying degrees in patients with albinism, thus, combined treatment of both systems will maximize visual function.

  17. Geographic Information Systems in Evaluation and Visualization of Construction Schedule

    CERN Document Server

    Bansal, V K

    2008-01-01

    Commercially available scheduling tools such as Primavera and Microsoft Project fail to provide information pertaining to the spatial aspects of construction project. A methodology using geographical information systems (GIS) is developed to represent spatial aspects of the construction progress graphically by synchronizing it with construction schedule. The spatial aspects are depicted by 3D model developed in AutoCAD and construction schedule is generated using Microsoft Excel. Spatial and scheduling information are linked together into the GIS environment (ArcGIS). The GIS-based system developed in this study may help in better understanding the schedule along with its spatial aspects.

  18. ANIMATION AND VISUALIZATION OF WATER QUALITY IN DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Water may undergo a number of changes in the distribution system, making the quality of the water at the customer's tap different from the quality of the water that leaves the treatment plant. Such changes in quality may be caused by chemical or biological variations or by a loss...

  19. Visual Based Retrieval Systems and Web Mining--Introduction.

    Science.gov (United States)

    Iyengar, S. S.

    2001-01-01

    Briefly discusses Web mining and image retrieval techniques, and then presents a summary of articles in this special issue. Articles focus on Web content mining, artificial neural networks as tools for image retrieval, content-based image retrieval systems, and personalizing the Web browsing experience using media agents. (AEF)

  20. Visualization of Processes in Self-Learning Systems

    NARCIS (Netherlands)

    Peters, Gabriele; Bunte, Kerstin; Strickert, Marc; Biehl, Michael; Villmann, Thomas

    2012-01-01

    One aspect of self-organizing systems is their desired ability to be self-learning, i.e., to be able to adapt dynamically to conditions in their environment. This quality is awkward especially if it comes to applications in security or safety-sensitive areas. Here a step towards more trustful

  1. Plasticity and stability of the visual system in human achiasma

    NARCIS (Netherlands)

    Hoffmann, M.B.; Kaule, F.; Levin, N.; Masuda, Y.; Kumar, A.; Gottlob, I.; Horiguchi, H.; Dougherty, R.F.; Stadler, J.; Wolynski, B.; Speck, O.; Kanowski, M.; Liao, Y.J.; Wandell, B.A.; Dumoulin, S.O.

    2012-01-01

    The absence of the optic chiasm is an extraordinary and extreme abnormality in the nervous system. The abnormality produces highly atypical functional responses in the cortex, including overlapping hemifield representations and bilateral population receptive fields in both striate and extrastriate v

  2. ANIMATION AND VISUALIZATION OF WATER QUALITY IN DISTRIBUTION SYSTEMS

    Science.gov (United States)

    Water may undergo a number of changes in the distribution system, making the quality of the water at the customer's tap different from the quality of the water that leaves the treatment plant. Such changes in quality may be caused by chemical or biological variations or by a loss...

  3. Audio-Visual Attractors for Capturing Attention to the Screens When Walking in CAVE Systems

    OpenAIRE

    Grani, Francesco; Argelaguet Sanz, Ferran; Gouranton, Valérie; Badawi, Marwan; Gaugne, Ronan; Serafin, Stefania; Lécuyer, Anatole

    2014-01-01

    International audience; In four-sided CAVE-like VR systems, the absence of the rear wall has been shown to decrease the level of immersion and can introduce breaks in presence. In this paper it is investigated to which extent user's attention can be driven by visual and auditory stimuli in a four-sided CAVE-like system. An experiment was conducted in order to analyze how user attention is diverted while physically walking in a virtual environment, when audio and/or visual attractors are prese...

  4. BlindNav: A Smartphone Based Navigation System for the Visually Impaired

    Directory of Open Access Journals (Sweden)

    Varsha Varadarajan

    2014-04-01

    Full Text Available Navigating in an indoor building and finding path to common locations is one of the primary concerns for visually challenged people. When the blind or visually impaired find themselves in an area they are not familiar with, they feel lost and their safety is at great risk. Current systems do not function in GPS-denied indoor environments and only do identification of particular landmarks encountered by user. As an attempt to address this problem, we present an indoor navigation system based on WiFi strength calculation which is easy to use and highly efficient.

  5. Integrating Interactive Visualizations in the Search Process of Digital Libraries and IR Systems

    CERN Document Server

    Hienert, Daniel; Schaer, Philipp; Mayr, Philipp

    2012-01-01

    Interactive visualizations for exploring and retrieval have not yet become an integral part of digital libraries and information retrieval systems. We have integrated a set of interactive graphics in a real world social science digital library. These visualizations support the exploration of search queries, results and authors, can filter search results, show trends in the database and can support the creation of new search queries. The use of weighted brushing supports the identification of related metadata for search facets. We discuss some use cases of the combination of IR systems and interactive graphics. In a user study we verify that users can gain insights from statistical graphics intuitively and can adopt interaction techniques.

  6. A distributed system for visualizing and analyzing multivariate and multidisciplinary data

    Science.gov (United States)

    Jacobson, Allan S.; Allen, Mark; Bailey, Michael; Blom, Ronald; Blume, Leo; Elson, Lee

    1993-01-01

    THe Linked Windows Interactive Data System (LinkWinds) is being developed with NASA support. The objective of this proposal is to adapt and apply that system in a complex network environment containing elements to be found by scientists working multidisciplinary teams on very large scale and distributed data sets. The proposed three year program will develop specific visualization and analysis tools, to be exercised locally and remotely in the LinkWinds environment, to demonstrate visual data analysis, interdisciplinary data analysis and cooperative and interactive televisualization and analysis of data by geographically separated science teams. These demonstrators will involve at least two science disciplines with the aim of producing publishable results.

  7. A WebGIS-based system for analyzing and visualizing air quality data for Shanghai Municipality

    Science.gov (United States)

    Wang, Manyi; Liu, Chaoshun; Gao, Wei

    2014-10-01

    An online visual analytical system based on Java Web and WebGIS for air quality data for Shanghai Municipality was designed and implemented to quantitatively analyze and qualitatively visualize air quality data. By analyzing the architecture of WebGIS and Java Web, we firstly designed the overall scheme for system architecture, then put forward the software and hardware environment and also determined the main function modules for the system. The visual system was ultimately established with the DIV + CSS layout method combined with JSP, JavaScript, and some other computer programming languages based on the Java programming environment. Moreover, Struts, Spring, and Hibernate frameworks (SSH) were integrated in the system for the purpose of easy maintenance and expansion. To provide mapping service and spatial analysis functions, we selected ArcGIS for Server as the GIS server. We also used Oracle database and ESRI file geodatabase to store spatial data and non-spatial data in order to ensure the data security. In addition, the response data from the Web server are resampled to implement rapid visualization through the browser. The experimental successes indicate that this system can quickly respond to user's requests, and efficiently return the accurate processing results.

  8. Visualizing uncertainties in a storm surge ensemble data assimilation and forecasting system

    KAUST Repository

    Hollt, Thomas

    2015-01-15

    We present a novel integrated visualization system that enables the interactive visual analysis of ensemble simulations and estimates of the sea surface height and other model variables that are used for storm surge prediction. Coastal inundation, caused by hurricanes and tropical storms, poses large risks for today\\'s societies. High-fidelity numerical models of water levels driven by hurricane-force winds are required to predict these events, posing a challenging computational problem, and even though computational models continue to improve, uncertainties in storm surge forecasts are inevitable. Today, this uncertainty is often exposed to the user by running the simulation many times with different parameters or inputs following a Monte-Carlo framework in which uncertainties are represented as stochastic quantities. This results in multidimensional, multivariate and multivalued data, so-called ensemble data. While the resulting datasets are very comprehensive, they are also huge in size and thus hard to visualize and interpret. In this paper, we tackle this problem by means of an interactive and integrated visual analysis system. By harnessing the power of modern graphics processing units for visualization as well as computation, our system allows the user to browse through the simulation ensembles in real time, view specific parameter settings or simulation models and move between different spatial and temporal regions without delay. In addition, our system provides advanced visualizations to highlight the uncertainty or show the complete distribution of the simulations at user-defined positions over the complete time series of the prediction. We highlight the benefits of our system by presenting its application in a real-world scenario using a simulation of Hurricane Ike.

  9. Visual presentation of dynamic systems with hyperbolic planar symmetry

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ning [Faculty of Information and Control Engineering, Shenyang Jianzhu University, Shenyang 110168 (China)], E-mail: n_chen@126.com; Li Zichuan; Jin Yuanyuan [Faculty of Information and Control Engineering, Shenyang Jianzhu University, Shenyang 110168 (China)

    2009-04-30

    Hyperbolic symmetric mappings defined on hyperbolic tilings are investigated. Ljapunov exponents of the dynamic systems are computed with the Euclidean distance. The parameter combinations with great impact on the characteristics of the dynamic systems were chosen as the window coordinates for construction of generalized Mandelbrot sets. The accelerated direct search algorithm is used to search for the set of the critical points in the fundamental region. The parameter space is separated into chaotic, periodic and mixed regions by the Ljapunov exponents of the critical points. The generalized Mandelbrot sets (M-set), which are the cross-sections of the parameter space, were constructed. Three different types of hyperbolic symmetry patterns, which are chaotic attractors, filled-in Julia sets and mixed images composed of an attractor and a filled-in Julia set from the same set of parameters, were created by using parameters from this kind of M-sets.

  10. Flight Simulator: Evaluation of SODERN Visualization System SVS-14.

    Science.gov (United States)

    1985-09-01

    29 96 rfgrmance characteristics visull diselay system 19 ABSTRACT iContinur on reverl if neceuary and identify by block nurnberi Engineering and Human...image, good picture aI dynamics with AVTS/IG video, excellent color rendition an contrast Human Factor Studies. Following the successful acceptance of...leads to the final comments as per attached data sheets in annex 2 p 1 to 6. The basic data from which these values are taken is the SODERN

  11. Low Cost, Wide Angle Infinity Optics Visual System.

    Science.gov (United States)

    1981-09-01

    straight edges of the sides that were to be joined. Mineral oil was used as the cooling fluid in the milling process to Prevent any possible water...maximum ana]e at the system eye noint of:16.2" 0 -6.2 x 500 , or 50.630. If the scannino format on the camera tube is not chanqed, it becomes nuite

  12. Geographic Information Systems in Evaluation and Visualization of Construction Schedule

    OpenAIRE

    Bansal, V. K.; Pal, Mahesh

    2008-01-01

    Commercially available scheduling tools such as Primavera and Microsoft Project fail to provide information pertaining to the spatial aspects of construction project. A methodology using geographical information systems (GIS) is developed to represent spatial aspects of the construction progress graphically by synchronizing it with construction schedule. The spatial aspects are depicted by 3D model developed in AutoCAD and construction schedule is generated using Microsoft Excel. Spatial and ...

  13. Investigation of a Simple Visual System for Flight Control

    Science.gov (United States)

    2011-07-01

    wings or ocelli Mizunami, The diversity of insect ocellar systems, 1994 Fleas lice proturans Dragonflies and damselflies mayflies 7 Identifying...and some do not). – Dragonflies vs. nearctic owlflies •Same sensor suites different behaviors – Very different flight, but all have the same sensor...Flight setup, by David Forester. Network 13 Similar behaving insects, different sensors. \\.J ••• • AFR .!;l 14 Dragonfly in field \\.J ••• • , AFR

  14. A Novel Visual Data Mining Module for the Geographical Information System gvSIG

    Directory of Open Access Journals (Sweden)

    Romel Vázquez-Rodríguez

    2013-01-01

    Full Text Available The exploration of large GIS models containing spatio-temporal information is a challenge. In this paper we propose the integration of scientific visualization (ScVis techniques into geographic information systems (GIS as an alternative for the visual analysis of data. Providing GIS with such tools improves the analysis and understanding of datasets with very low spatial density and allows to find correlations between variables in time and space. In this regard, we present a new visual data mining tool for the GIS gvSIG. This tool has been implemented as a gvSIG module and contains several ScVis techniques for multiparameter data with a wide range of possibilities to explore interactively the data. The developed module is a powerful visual data mining and data visualization tool to obtain knowledge from multiple datasets in time and space. A real case study with meteorological data from Villa Clara province (Cuba is presented, where the implemented visualization techniques were used to analyze the available datasets. Although it is tested with meteorological data, the developed module is of general application in the sense that it can be used in multiple application fields related with Earth Sciences.

  15. Visualizing genome and systems biology: technologies, tools, implementation techniques and trends, past, present and future.

    Science.gov (United States)

    Pavlopoulos, Georgios A; Malliarakis, Dimitris; Papanikolaou, Nikolas; Theodosiou, Theodosis; Enright, Anton J; Iliopoulos, Ioannis

    2015-01-01

    "Α picture is worth a thousand words." This widely used adage sums up in a few words the notion that a successful visual representation of a concept should enable easy and rapid absorption of large amounts of information. Although, in general, the notion of capturing complex ideas using images is very appealing, would 1000 words be enough to describe the unknown in a research field such as the life sciences? Life sciences is one of the biggest generators of enormous datasets, mainly as a result of recent and rapid technological advances; their complexity can make these datasets incomprehensible without effective visualization methods. Here we discuss the past, present and future of genomic and systems biology visualization. We briefly comment on many visualization and analysis tools and the purposes that they serve. We focus on the latest libraries and programming languages that enable more effective, efficient and faster approaches for visualizing biological concepts, and also comment on the future human-computer interaction trends that would enable for enhancing visualization further.

  16. Structural and functional brain changes beyond visual system in patients with advanced glaucoma.

    Science.gov (United States)

    Frezzotti, Paolo; Giorgio, Antonio; Motolese, Ilaria; De Leucio, Alessandro; Iester, Michele; Motolese, Eduardo; Federico, Antonio; De Stefano, Nicola

    2014-01-01

    In order to test the hypothesis that in primary open angle glaucoma (POAG), an important cause of irreversible blindness, a spreading of neurodegeneration occurs through the brain, we performed multimodal MRI and subsequent whole-brain explorative voxelwise analyses in 13 advanced POAG patients and 12 age-matched normal controls (NC). Altered integrity (decreased fractional anisotropy or increased diffusivities) of white matter (WM) tracts was found not only along the visual pathway of POAG but also in nonvisual WM tracts (superior longitudinal fascicle, anterior thalamic radiation, corticospinal tract, middle cerebellar peduncle). POAG patients also showed brain atrophy in both visual cortex and other distant grey matter (GM) regions (frontoparietal cortex, hippocampi and cerebellar cortex), decreased functional connectivity (FC) in visual, working memory and dorsal attention networks and increased FC in visual and executive networks. In POAG, abnormalities in structure and FC within and outside visual system correlated with visual field parameters in the poorer performing eyes, thus emphasizing their clinical relevance. Altogether, this represents evidence that a vision disorder such as POAG can be considered a widespread neurodegenerative condition.

  17. A simpler primate brain: the visual system of the marmoset monkey.

    Science.gov (United States)

    Solomon, Samuel G; Rosa, Marcello G P

    2014-01-01

    Humans are diurnal primates with high visual acuity at the center of gaze. Although primates share many similarities in the organization of their visual centers with other mammals, and even other species of vertebrates, their visual pathways also show unique features, particularly with respect to the organization of the cerebral cortex. Therefore, in order to understand some aspects of human visual function, we need to study non-human primate brains. Which species is the most appropriate model? Macaque monkeys, the most widely used non-human primates, are not an optimal choice in many practical respects. For example, much of the macaque cerebral cortex is buried within sulci, and is therefore inaccessible to many imaging techniques, and the postnatal development and lifespan of macaques are prohibitively long for many studies of brain maturation, plasticity, and aging. In these and several other respects the marmoset, a small New World monkey, represents a more appropriate choice. Here we review the visual pathways of the marmoset, highlighting recent work that brings these advantages into focus, and identify where additional work needs to be done to link marmoset brain organization to that of macaques and humans. We will argue that the marmoset monkey provides a good subject for studies of a complex visual system, which will likely allow an important bridge linking experiments in animal models to humans.

  18. Feasibility and performance evaluation of generating and recording visual evoked potentials using ambulatory Bluetooth based system.

    Science.gov (United States)

    Ellingson, Roger M; Oken, Barry

    2010-01-01

    Report contains the design overview and key performance measurements demonstrating the feasibility of generating and recording ambulatory visual stimulus evoked potentials using the previously reported custom Complementary and Alternative Medicine physiologic data collection and monitoring system, CAMAS. The methods used to generate visual stimuli on a PDA device and the design of an optical coupling device to convert the display to an electrical waveform which is recorded by the CAMAS base unit are presented. The optical sensor signal, synchronized to the visual stimulus emulates the brain's synchronized EEG signal input to CAMAS normally reviewed for the evoked potential response. Most importantly, the PDA also sends a marker message over the wireless Bluetooth connection to the CAMAS base unit synchronized to the visual stimulus which is the critical averaging reference component to obtain VEP results. Results show the variance in the latency of the wireless marker messaging link is consistent enough to support the generation and recording of visual evoked potentials. The averaged sensor waveforms at multiple CPU speeds are presented and demonstrate suitability of the Bluetooth interface for portable ambulatory visual evoked potential implementation on our CAMAS platform.

  19. Dynamic Visualization of SNS Diagnostics Summary Report and System Status

    CERN Document Server

    Blokland, Willem; Long, Cary D; Murphy, Darryl J; Purcell, John D; Sundaram, Madhan

    2005-01-01

    The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based running Embedded Windows XP and LabVIEW. The diagnostics instruments communicate with the control system using the Channel Access (CA) protocol of the Experimental Physics and Industrial Control System (EPICS). This paper describes the Diagnostics Group's approach to collecting data from the instruments, processing it, and presenting live in a summarized way over the web. Effectively, adding a supervisory level to the diagnostics instruments. One application of this data mining is the "Diagnostics Status Page" that summarizes the insert-able devices, transport efficiencies, and the mode of the accelerator in a compact webpage. The displays on the webpage change automatically to show the latest and/o...

  20. A 3D visualization system for molecular structures

    Science.gov (United States)

    Green, Terry J.

    1989-01-01

    The properties of molecules derive in part from their structures. Because of the importance of understanding molecular structures various methodologies, ranging from first principles to empirical technique, were developed for computing the structure of molecules. For large molecules such as polymer model compounds, the structural information is difficult to comprehend by examining tabulated data. Therefore, a molecular graphics display system, called MOLDS, was developed to help interpret the data. MOLDS is a menu-driven program developed to run on the LADC SNS computer systems. This program can read a data file generated by the modeling programs or data can be entered using the keyboard. MOLDS has the following capabilities: draws the 3-D representation of a molecule using stick, ball and ball, or space filled model from Cartesian coordinates, draws different perspective views of the molecule; rotates the molecule on the X, Y, Z axis or about some arbitrary line in space, zooms in on a small area of the molecule in order to obtain a better view of a specific region; and makes hard copy representation of molecules on a graphic printer. In addition, MOLDS can be easily updated and readily adapted to run on most computer systems.

  1. Biochemical evidence that L-glutamate is a neurotransmitter of primary vagal afferent nerve fibers

    Energy Technology Data Exchange (ETDEWEB)

    Perrone, M.H. (Cornell Univ., New York (USA). Medical Coll.)

    1981-12-28

    To determine in rat if vagal afferent fibers projecting into the intermediate one third of the nucleus tractus solitarius (NTS), the site of termination of baroafferents, utilize glutamate as a neurotransmitter, the high-affinity uptake of (/sup 3/H)L-glutamate and content of glutamate were analyzed in micropunches of rat brain stem. The intermediate NTS contains a high-affinity synaptosomal uptake system for (/sup 3/H)L-glutamate that is greater in capacity than that in areas adjacent to the NTS; it is almost two-fold higher than uptake in medial septum and nucleus accumbens and equal to that of hippocampal regions purportedly containing a rich glutamatergic innervation. Unilateral ablation of the nodose ganglion (i.e. cells of origin of vagal afferents) resulted, within 24 h in a prolonged significant reduction, to 56% of control, of (/sup 3/H)L-glutamate uptake, bilaterally in the NTS. The reduction of Na/sup +/-dependent synaptosomal uptake of (/sup 3/H)L-glutamate, resulted from a decrease in Vsub(max) without change in the Ksub(m) of the process, was anatomically restricted to the intermediate NTS, and was not associated with changes in (/sup 3/H)GABA uptake. The content of glutamate in the NTS was significantly (P < 0.01) decreased by 30% 7 days following unilateral extirpation of the nodose ganglion without changes in the concentrations of aspartate, glycine, glutamine, or GABA. A population of vagal afferent fibers projecting to NTS are glutamatergic. The results are consistent with the hypothesis obtained by physiological and pharmacological techniques that glutamate is a neurotransmitter of baroafferents.

  2. Decoding of the spike timing of primary afferents during voluntary arm movements in monkeys

    Directory of Open Access Journals (Sweden)

    Tatsuya eUmeda

    2014-05-01

    Full Text Available Understanding the mechanisms of encoding forelimb kinematics in the activity of peripheral afferents is essential for determining the optimal parameters of afferent stimulation to transmit proprioceptive signals in neuroprosthetics. To investigate whether the spike timing of dorsal root ganglion (DRG neurons could be estimated from the forelimb kinematics of behaving monkeys, we implanted two multi-electrode arrays chronically in the DRGs at the level of the cervical segments in two monkeys. Neuronal activity during voluntary reach-to-grasp movements were recorded simultaneously with the trajectories of hand/arm movements, which were tracked in three-dimensional space using a motion capture system. Sixteen and 13 neurons, including muscle spindles, skin receptors, and tendon organ afferents, were recorded in the two monkeys, respectively. We were able to reconstruct forelimb joint kinematics from the temporal firing pattern of a subset of DRG neurons using sparse linear regression (SLiR analysis, suggesting that DRG neuronal ensembles encoded information about joint kinematics. Furthermore, we estimated the spike timing of the DRG neuronal ensembles from joint kinematics using an integrate-and-fire model (IF incorporating the SLiR algorithm. The temporal change of firing frequency of a subpopulation of neurons was reconstructed precisely from forelimb kinematics using the SLiR. The spike timing of the DRG neurons was calculated using an IF model, in which a spike occurs if the cumulative sum of the firing frequency value exceeded a constant threshold. The estimated firing pattern of the DRG neuronal ensembles encoded forelimb joint angles and velocities as precisely as the originally recorded neuronal activity. These results suggest that the simple model can be used to generate an accurate estimate of the spike timing of DRG neuronal ensembles from forelimb joint kinematics, and is useful for designing a proprioceptive decoder in a brain machine

  3. Google Earth-based dynamic visualization system for storm surge flood routing

    Institute of Scientific and Technical Information of China (English)

    Liu Donghai; Wang Qian; Zuo Wentao

    2013-01-01

    To describe the dynamic process of flood routing intuitively and realistically when storm surge disaster occurs,a method for ArcGIS data and Google Earth (GE) data integration is proposed,which realizes the impor-ting and integrating of basic geographic information into GE. Based on SketchUp and AutoCAD software,three-dimension (3D) visualization of seawall and other tidal defense structures is achieved. By employing Microsoft Foundation Class Library (MFC),the related system modules and storm surge flood routing dynamic visualization system are developed. Therefore,dynamic visualization of flood routing process and interactive query of sub-merged area and inundated depth are implemented. A practical application case study of Tianjin Binhai New Area provides decision-making support for coastal seawall planning and storm surge disaster prevention and reduction.

  4. SoundView: an auditory guidance system based on environment understanding for the visually impaired people.

    Science.gov (United States)

    Nie, Min; Ren, Jie; Li, Zhengjun; Niu, Jinhai; Qiu, Yihong; Zhu, Yisheng; Tong, Shanbao

    2009-01-01

    Without visual information, the blind people live in various hardships with shopping, reading, finding objects and etc. Therefore, we developed a portable auditory guide system, called SoundView, for visually impaired people. This prototype system consists of a mini-CCD camera, a digital signal processing unit and an earphone, working with built-in customizable auditory coding algorithms. Employing environment understanding techniques, SoundView processes the images from a camera and detects objects tagged with barcodes. The recognized objects in the environment are then encoded into stereo speech signals for the blind though an earphone. The user would be able to recognize the type, motion state and location of the interested objects with the help of SoundView. Compared with other visual assistant techniques, SoundView is object-oriented and has the advantages of cheap cost, smaller size, light weight, low power consumption and easy customization.

  5. In Internet-Based Visualization System Study about Breakthrough Applet Security Restrictions

    OpenAIRE

    Chen, Jie; Huang, Yan

    2009-01-01

    International audience; In the process of realization Internet-based visualization system of the protein molecules, system needs to allow users to use the system to observe the molecular structure of the local computer, that is, customers can generate the three-dimensional graphics from PDB file on the client computer. This requires Applet access to local file, related to the Applet security restrictions question. In this paper include two realization methods: 1.Use such as signature tools, k...

  6. Rapid prototyping with the visual data environment of an OFDM WLAN system

    OpenAIRE

    Serra i Serra, Moisès; Martí i Puig, Pere; Carrabina, Jordi

    2005-01-01

    In this paper a rapid prototyping design flow is presented and applied to a prototype of the base-band physical layer of a Hiperlan/2 WLAN transceiver. This physical layer is a high performance multi-rate system that contains computationally intensive algorithms. A new method for prototyping the design flow and verifying the process is to use the latest generation of system level design environments (visual data flow environment) for DSPs. The System Generator and Matlab/Simulink ...

  7. NEURAL PATHWAYS OF TRIGEMINAL PROPRIOCEPTIVE AFFERENTS COORDINATE ORAL MOTOR BEHAVIORS

    Institute of Scientific and Technical Information of China (English)

    Luo Pifu; Zhang Jingdong; Li Jishuo

    2003-01-01

    Neural pathways and synaptic connections from the trigeminal mesencephalic nucleus (Vme) neurons to the cranial motor nuclei were studied in the rat using double labelling methodologies of intracellular Neurobiotin staining combined with retrograde horseradish peroxidase (HRP) transport, anterograde biotinylated dextran amine (BDA) tracing combined with retrograde HRP transport, and a dual fluorescent labelling of BDA anterograde combined tracing with Cholera Toxin B (CTB) retrograde transport. Direct projections and synapses were demonstrated from Vme neuronal boutons to motoneurons (MNs) of the trigeminal motor nucleus (Vmo), the hypoglossal nucleus (Ⅻ) and the ambiguus nucleus (Amb). Indirect projections and pathways from Vme neurons to the cranial motor nuclei including Vmo, Ⅻ, the facial nucleus (Ⅶ) and the cervical spinal cord (C1~5) were seen to relay on their premotor neurons. The premotor neurons of above cranial motor nuclei were overlapped in bilateral premotor neuronal pool including the parvocellular reticular formation (PCRt) and its alpha division (PCRtA), the dorsomedial part of the spinal trigeminal nucleus oralis (Vodm), and interpolaris (Vidm), the medullary reticular nucleus dorsal division (MdD), the supratrigeminal region (Vsup) and the dorsomedial part of the principal trigeminal sensory nucleus (Vpdm).Synapses between Vme neuronal boutons and Vmo and Ⅻ MNs and Ⅻ premotor neurons were predominantly asymmetric.There were four types of synaptic organizations, i.e. synaptic convergence; synaptic divergence presynaptic inhibition and afferent feedforward inhibition seen between Vme boutons and Vmno, Ⅻ MNs and between Vme boutons and Ⅻ premotor neurons.The results of present studies have demonstrated direct pathways from the trigeminal proprioceptive afferents to Vmo, Ⅻ and Amb MNs, and indirect pathways from the trigeminal proprioceptive afferents to bilateral Vmno, Ⅻ, Ⅶ and C1~s via their premotor neurons. It provides

  8. Mechanically insensitive afferents (MIAs) in cutaneous nerves of monkey.

    Science.gov (United States)

    Meyer, R A; Davis, K D; Cohen, R H; Treede, R D; Campbell, J N

    1991-10-11

    A problem in the study of nociceptors is that intense stimuli are used to locate the receptive field (RF), and thus the receptor may be damaged before the first responses are recorded. In addition, some nociceptors do not respond to the mechanical stimuli often used to search for the RF. To overcome these problems, an electrical search technique was developed to locate the RF of cutaneous nociceptors. In the hairy skin of anesthetized monkey, we used this technique to locate the RF of 63 A delta-fibers and 22 C-fibers that had extremely high thresholds or were unresponsive to mechanical stimuli. We refer to these afferents as mechanically insensitive afferents (MIAs). Ten A delta-fiber MIAs had a short latency response to stepped heat stimuli and could be responsible for first pain sensation. Five A delta-fiber MIAs and one C-fiber MIA did not respond to mechanical or heat stimuli but did respond to injection into the electrical RF of an artificial inflammatory soup containing histamine, bradykinin, prostaglandin E1, and serotonin. These chemoreceptors might be responsible for the pain and itch sensations that result from chemical stimuli. Some MIAs became more responsive to mechanical stimuli after injection into the RF of the inflammatory soup and, thus, may contribute to the hyperalgesia to mechanical stimuli associated with cutaneous injury. A large proportion of the A delta-fiber (48%) and C-fiber (30%) afferents in this study were insensitive to mechanical stimuli. The role of these MIAs in sensation needs to be studied further. The electrical search technique enables a systematic study of these afferents to be performed. This technique may also be of use to identify and characterize dorsal horn neurons that have inputs from MIAs.

  9. Characterisation of the primary afferent spinal innervation of mouse uterus

    Directory of Open Access Journals (Sweden)

    Geraldine eHerweijer

    2014-07-01

    Full Text Available The primary afferent innervation of the uterus is incompletely understood. The aim of this study was to identify the location and characteristics of primary afferent neurons that innervate the uterine horn of mice and correlate the different morphological types of putative primary afferent nerve endings, immunoreactive to the sensory marker, calcitonin gene related peptide (CGRP. Using retrograde tracing, injection of 5-10µL of 1,1'-didodecyl-3,3,3,3'-tetramethylindocarbocyanine perchlorate (DiI into discrete single sites in each uterine horn revealed a biomodal distribution of sensory neurons in dorsal root ganglia (DRG with peak labelling occurring between T13-L3 and a second smaller peak between L6-S1. The mean cross sectional area of labelled cells was 463 µm2 +/- SEM. A significantly greater proportion of labelled neurons consisted of small cell bodies (<300 µm2 in the sacral spinal cord (S2 compared with peak labelling at the lumbar (L2 region. In both sections and whole mount preparations, immunohistochemical staining for CGRP revealed substantial innervation of the uterus by CGRP-positive nerve fibres located primarily at the border between the circular and longitudinal muscle layers (N=4. The nerve endings were classified into three distinct types: single, branching or complex, that often aligned preferentially in either the circular or longitudinal axis of the smooth muscles. Complex endings were often associated with mesenteric vessels. We have identified that the cell bodies of primary afferent neurons innervating the mouse uterus lie primarily in DRG at L2 and S1 spinal levels. Also, the greatest density of CGRP immunoreactivity lies within the myometrium, with at least three different morphological types of nerve endings identified. These findings will facilitate further investigations into the mechanisms underlying sensory transduction in mouse uterus.

  10. Rapid inhibition of vasoconstriction in renal afferent arterioles by aldosterone.

    Science.gov (United States)

    Uhrenholt, T R; Schjerning, J; Hansen, P B; Nørregaard, R; Jensen, B L; Sorensen, G L; Skøtt, O

    2003-12-12

    Aldosterone has been suggested to elicit vessel contraction via a nongenomic mechanism. We tested this proposal in microdissected, perfused rabbit renal afferent arterioles. Aldosterone had no effect on internal diameter in concentrations from 10(-10) to 10(-5) mol/L, but aldosterone abolished the ability of 100 mmol/L KCl to induce vascular contraction. The inhibitory effect of aldosterone was observed from 1 pmol/L. The inhibitory effect was significant after 5 minutes and maximal after 20 minutes and was fully reversible. Actinomycin D (10(-6) mol/L) prolonged the effect of aldosterone. The effect was abolished by the mineralocorticoid receptor antagonist spironolactone (10(-7) mol/L) but not by the glucocorticoid receptor antagonist mifepristone (10(-6) mol/L). The K+-mediated increase of intracellular calcium concentration in afferent arterioles was not affected by aldosterone. Mineralocorticoid receptor was detected by reverse transcription-polymerase chain reaction and immunohistochemistry in rat renal vasculature and rabbit endothelial cells. Inhibition of phosphatidylinositol (PI)-3 kinase with LY 294002 (3x10(-6) mol/L) restored sensitivity to K+ in the presence of aldosterone, and afferent arterioles were immunopositive for PI-3 kinase subunit p110alpha. Inhibition of NO formation by L-NAME (10(-4) mol/L) or inhibition of soluble guanylyl cyclase with 1H-(1,2,4)Oxadiazolo[4,3-a]quinoxaline-1-one restored K+-induced vasoreactivity in the presence of aldosterone. Similar to aldosterone, the NO donor sodium nitroprusside inhibited K+-induced vascular contraction. Geldanamycin (10(-6) mol/L), an inhibitor of heat shock protein 90, abolished aldosterone-induced vasorelaxation. We conclude that aldosterone inhibits depolarization-induced vasoconstriction in renal afferent arterioles by a rapid nongenomic mechanism that is initiated by mineralocorticoid receptor activation and involves PI-3 kinase, protein kinase B, and heat shock protein 90-mediated

  11. How to test for a relative afferent pupillary defect (RAPD

    Directory of Open Access Journals (Sweden)

    David C Broadway

    2012-01-01

    Full Text Available The 'swinging light test' is used to detect a relative afferent pupil defect (RAPD: a means of detecting differences between the two eyes in how they respond to a light shone in one eye at a time. The test can be very useful for detecting unilateral or asymmetrical disease of the retina or optic nerve (but only optic nerve disease that occurs in front of the optic chiasm.

  12. Real-Time Grouting Monitoring and Visualization Analysis System for Dam Foundation Curtain Grouting

    Institute of Scientific and Technical Information of China (English)

    樊贵超; 钟登华; 任炳昱; 崔博; 李晓超; 岳攀

    2016-01-01

    A real-time monitoring and 3D visualization analysis system is proposed for dam foundation curtain grouting. Based on the real-time control technology, the optimization method and the set theory, a mathematical model of the system is established. The real-time collection and transmission technology of the grouting data pro-vides a data foundation for the system. The real-time grouting monitoring and dynamic alarming method helps the system control the grouting quality during the grouting process, thus, the abnormalities of grouting, such as jacking and hydraulic uplift, can be effectively controlled. In addition, the 3D grouting visualization analysis technology is proposed to establish the grouting information model(GIM). The GIM provides a platform to visualize and ana-lyze the grouting process and results. The system has been applied to a hydraulic project of China as a case study, and the application results indicate that the real-time grouting monitoring and 3D visualization analysis for the grouting process can help engineers control the grouting quality more efficiently.

  13. Road Vehicle Monitoring System Based on Intelligent Visual Internet of Things

    Directory of Open Access Journals (Sweden)

    Qingwu Li

    2015-01-01

    Full Text Available In recent years, with the rapid development of video surveillance infrastructure, more and more intelligent surveillance systems have employed computer vision and pattern recognition techniques. In this paper, we present a novel intelligent surveillance system used for the management of road vehicles based on Intelligent Visual Internet of Things (IVIoT. The system has the ability to extract the vehicle visual tags on the urban roads; in other words, it can label any vehicle by means of computer vision and therefore can easily recognize vehicles with visual tags. The nodes designed in the system can be installed not only on the urban roads for providing basic information but also on the mobile sensing vehicles for providing mobility support and improving sensing coverage. Visual tags mentioned in this paper consist of license plate number, vehicle color, and vehicle type and have several additional properties, such as passing spot and passing moment. Moreover, we present a fast and efficient image haze removal method to deal with haze weather condition. The experiment results show that the designed road vehicle monitoring system achieves an average real-time tracking accuracy of 85.80% under different conditions.

  14. Data visualization

    CERN Document Server

    Azzam, Tarek

    2013-01-01

    Do you communicate data and information to stakeholders? In Part 1, we introduce recent developments in the quantitative and qualitative data visualization field and provide a historical perspective on data visualization, its potential role in evaluation practice, and future directions. Part 2 delivers concrete suggestions for optimally using data visualization in evaluation, as well as suggestions for best practices in data visualization design. It focuses on specific quantitative and qualitative data visualization approaches that include data dashboards, graphic recording, and geographic information systems (GIS). Readers will get a step-by-step process for designing an effective data dashboard system for programs and organizations, and various suggestions to improve their utility.

  15. On-Board Visual Tracking with Unmanned Aircraft System (UAS)

    CERN Document Server

    Qadir, Ashraf; Semke, William

    2012-01-01

    This paper presents the development of a real time tracking algorithm that runs on a 1.2 GHz PC/104 computer on-board a small UAV. The algorithm uses zero mean normalized cross correlation to detect and locate an object in the image. A kalman filter is used to make the tracking algorithm computationally efficient. Object position in an image frame is predicted using the motion model and a search window, centered at the predicted position is generated. Object position is updated with the measurement from object detection. The detected position is sent to the motion controller to move the gimbal so that the object stays at the center of the image frame. Detection and tracking is autonomously carried out on the payload computer and the system is able to work in two different methods. The first method starts detecting and tracking using a stored image patch. The second method allows the operator on the ground to select the interest object for the UAV to track. The system is capable of re-detecting an object, in t...

  16. Focusing the research agenda for simulation training visual system requirements

    Science.gov (United States)

    Lloyd, Charles J.

    2014-06-01

    Advances in the capabilities of the display-related technologies with potential uses in simulation training devices continue to occur at a rapid pace. Simultaneously, ongoing reductions in defense spending stimulate the services to push a higher proportion of training into ground-based simulators to reduce their operational costs. These two trends result in increased customer expectations and desires for more capable training devices, while the money available for these devices is decreasing. Thus, there exists an increasing need to improve the efficiency of the acquisition process and to increase the probability that users get the training devices they need at the lowest practical cost. In support of this need the IDEAS program was initiated in 2010 with the goal of improving display system requirements associated with unmet user needs and expectations and disrupted acquisitions. This paper describes a process of identifying, rating, and selecting the design parameters that should receive research attention. Analyses of existing requirements documents reveal that between 40 and 50 specific design parameters (i.e., resolution, contrast, luminance, field of view, frame rate, etc.) are typically called out for the acquisition of a simulation training display system. Obviously no research effort can address the effects of this many parameters. Thus, we developed a defensible strategy for focusing limited R&D resources on a fraction of these parameters. This strategy encompasses six criteria to identify the parameters most worthy of research attention. Examples based on display design parameters recommended by stakeholders are provided.

  17. GABA in Paraventricular Nucleus Regulates Adipose Afferent Reflex in Rats.

    Directory of Open Access Journals (Sweden)

    Lei Ding

    Full Text Available Chemical stimulation of white adipose tissue (WAT induces adipose afferent reflex (AAR, and thereby causes a general sympathetic activation. Paraventricular nucleus (PVN is important in control of sympathetic outflow. This study was designed to investigate the role of γ-aminobutyric acid (GABA in PVN in regulating the AAR.Experiments were carried out in anesthetized rats. Renal sympathetic nerve activity (RSNA and mean arterial pressure (MAP were continuously recorded. AAR was evaluated by the RSNA and MAP responses to electrical stimulation of the right epididymal WAT (eWAT afferent nerve. Electrical stimulation of eWAT afferent nerve increase RSNA. Bilateral microinjection of the GABAA receptor agonist isoguvacine or the GABAB receptor agonist baclofen attenuated the AAR. The effect of isoguvacine on the AAR was greater than that of baclofen. The GABAA receptor antagonist gabazine enhanced the AAR, while the GABAB receptor antagonist CGP-35348 had no significant effect on the AAR. Bilateral PVN microinjection of vigabatrin, a selective GABA-transaminase inhibitor, to increase endogenous GABA levels in the PVN abolished the AAR. The inhibitory effect of vigabatrin on the AAR was attenuated by the pretreatment with gabazine or CGP-35348. Pretreatment with combined gabazine and CGP-35348 abolished the effects of vigabatrin.Activation of GABAA or GABAB receptors in the PVN inhibits the AAR. Blockade of GABAA receptors in the PVN enhances the AAR. Endogenous GABA in the PVN plays an important role in regulating the AAR.

  18. Long-term visual and systemic prognoses of 83 cases of biopsy-proven sarcoid uveitis.

    Science.gov (United States)

    Rochepeau, Cédric; Jamilloux, Yvan; Kerever, Sebastien; Febvay, Camille; Perard, Laurent; Broussolle, Christiane; Burillon, Carole; Kodjikian, Laurent; Seve, Pascal

    2017-07-01

    To determine the long-term visual and systemic outcomes of uveitis patients with biopsy-proven sarcoidosis. A retrospective study of biopsy-proven sarcoid uveitis, with a 3-year minimum follow-up, seen at Lyon University Hospital, between April 2004 and January 2016. A total of 83 patients were included, with a median age at onset of 52 (37-62) years and an unbalanced gender ratio (women 77.1%). Thirty-one patients had original systemic sarcoidosis in addition to ocular localisation, whereas 52 initially presented with isolated sarcoid uveitis. Among the latter, 7.7% (n=4) developed an extraocular disease after a median follow-up duration of 60 (44-110) months. The systemic spread in these patients included cutaneous sarcoids (n=2), arthritis (n=1) and multiple mononeuritis (n=1). Complete visual recovery was obtained for 60.2% of all patients and 89.2% had retrieved best-corrected visual acuity (BCVA) >20/50 in both eyes. A unilateral loss of BCVA of worse than 20/200 was documented in two patients in the isolated sarcoid uveitis group. No patient suffered from bilateral severe visual impairment or blindness. Factors linked to a poor visual prognosis, defined by BCVA ≤20/50 in at least one eye, were chronic macular oedema (p=0.009) and persistent ocular inflammation (p=0.0005). In this large European series of biopsy-proven sarcoidosis to date, with a prolonged follow-up, sarcoid uveitis was suggestive of a favourable systemic and visual outcome. Clinically isolated uveitis that revealed sarcoidosis remained a strictly ocular condition in most cases. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Robots, systems, and methods for hazard evaluation and visualization

    Science.gov (United States)

    Nielsen, Curtis W.; Bruemmer, David J.; Walton, Miles C.; Hartley, Robert S.; Gertman, David I.; Kinoshita, Robert A.; Whetten, Jonathan

    2013-01-15

    A robot includes a hazard sensor, a locomotor, and a system controller. The robot senses a hazard intensity at a location of the robot, moves to a new location in response to the hazard intensity, and autonomously repeats the sensing and moving to determine multiple hazard levels at multiple locations. The robot may also include a communicator to communicate the multiple hazard levels to a remote controller. The remote controller includes a communicator for sending user commands to the robot and receiving the hazard levels from the robot. A graphical user interface displays an environment map of the environment proximate the robot and a scale for indicating a hazard intensity. A hazard indicator corresponds to a robot position in the environment map and graphically indicates the hazard intensity at the robot position relative to the scale.

  20. Optical mapping system for visualizing arrhythmias in isolated mouse atria.

    Science.gov (United States)

    Schmidt, Robyn; Nygren, Anders

    2006-01-01

    Optical mapping has become an important technique in the study of cardiac electrophysiology, especially in terms of investigating the mechanisms of cardiac arrhythmias. The increasing availability of transgenic mice as models for cardiovascular disease is driving the need for instrumentation suitable for the study of electrical activity in the mouse heart. In this paper we evaluate our optical mapping system's ability to clearly record induced arrhythmic activity in an isolated mouse atrial preparation. Preliminary results indicate that the signal quality is high enough that individual optically recorded action potentials can be discerned in many pixels, even without post-processing for noise removal. The optical mapping video is clear enough for general observations regarding the patterns of electrical propagation during arrhythmic behaviour. The induced arrhythmias appear to have a regular pattern of activity, and are likely best classified as atrial tachycardias.

  1. Visual system based on artificial retina for motion detection.

    Science.gov (United States)

    Barranco, Francisco; Díaz, Javier; Ros, Eduardo; del Pino, Begoña

    2009-06-01

    We present a bioinspired model for detecting spatiotemporal features based on artificial retina response models. Event-driven processing is implemented using four kinds of cells encoding image contrast and temporal information. We have evaluated how the accuracy of motion processing depends on local contrast by using a multiscale and rank-order coding scheme to select the most important cues from retinal inputs. We have also developed some alternatives by integrating temporal feature results and obtained a new improved bioinspired matching algorithm with high stability, low error and low cost. Finally, we define a dynamic and versatile multimodal attention operator with which the system is driven to focus on different target features such as motion, colors, and textures.

  2. Beyond blindsight: properties of visual relearning in cortically blind fields.

    Science.gov (United States)

    Das, Anasuya; Tadin, Duje; Huxlin, Krystel R

    2014-08-27

    Damage to the primary visual cortex (V1) or its immediate afferents results in a dense scotoma, termed cortical blindness (CB). CB subjects have residual visual abilities, or blindsight, which allow them to detect and sometimes discriminate stimuli with high temporal and low spatial frequency content. Recent work showed that with training, discriminations in the blind field can become more reliable, and even reach consciousness. However, the narrow spatiotemporal bandwidth of blindsight limits its functional usefulness in everyday vision. Here, we asked whether visual training can induce recovery outside the spatiotemporal bandwidth of blindsight. Specifically, could human CB subjects learn to discriminate static, nonflickering stimuli? Can such learning transfer to untrained stimuli and tasks, and does double training with moving and static stimuli provide additional advantages relative to static training alone? We found CB subjects capable of relearning static orientation discriminations following single as well as double training. However, double training with complex, moving stimuli in a separate location was necessary to recover complex motion thresholds at locations trained with static stimuli. Subjects trained on static stimuli alone could only discriminate simple motion. Finally, both groups had approximately equivalent, incomplete recovery of fine orientation and direction discrimination thresholds, as well as contrast sensitivity. These results support two conclusions: (1) from a practical perspective, complex moving stimuli and double training may be superior training tools for inducing visual recovery in CB, and (2) the cortically blind visual system can relearn to perform a wider range of visual discriminations than predicted by blindsight alone.

  3. Knowledge integrated visual analysis system for in-depth management of bridge safety and maintenance

    Science.gov (United States)

    Wang, Xiaoyu; Dou, Wenwen; Vatcha, Rashna; Liu, Wanqiu; Chen, Shen-En; Lee, Seok-Won; Chang, Remco; Ribarsky, William

    2009-05-01

    Infrastructure safety affects millions of U.S citizens in many ways. Among all the infrastructures, the bridge plays a significant role in providing substantial economy and public safety. Nearly 600,000 bridges across the U.S are mandated to be inspected every twenty-four months. Although these inspections could generate great amount of rich data for bridge engineers to make critical maintenance decisions, processing these data has become challenging due to the low efficiency from those traditional bridge management systems. In collaboration with North Carolina Department of Transportation (NCDOT) and other regional DOT collaborators, we present our knowledge integrated visual analytics bridge management system. Our system aims to provide bridge engineers a highly interactive data exploration environment as well as knowledge pools for corresponding bridge information. By integrating the knowledge structure with visualization system, our system could provide comprehensive understandings of the bridge assets and enables bridge engineers to investigate potential bridge safety issues and make maintenance decisions.

  4. Force sensor in simulated skin and neural model mimic tactile SAI afferent spiking response to ramp and hold stimuli

    Directory of Open Access Journals (Sweden)

    Kim Elmer K

    2012-07-01

    Full Text Available Abstract Background The next generation of prosthetic limbs will restore sensory feedback to the nervous system by mimicking how skin mechanoreceptors, innervated by afferents, produce trains of action potentials in response to compressive stimuli. Prior work has addressed building sensors within skin substitutes for robotics, modeling skin mechanics and neural dynamics of mechanotransduction, and predicting response timing of action potentials for vibration. The effort here is unique because it accounts for skin elasticity by measuring force within simulated skin, utilizes few free model parameters for parsimony, and separates parameter fitting and model validation. Additionally, the ramp-and-hold, sustained stimuli used in this work capture the essential features of the everyday task of contacting and holding an object. Methods This systems integration effort computationally replicates the neural firing behavior for a slowly adapting type I (SAI afferent in its temporally varying response to both intensity and rate of indentation force by combining a physical force sensor, housed in a skin-like substrate, with a mathematical model of neuronal spiking, the leaky integrate-and-fire. Comparison experiments were then conducted using ramp-and-hold stimuli on both the spiking-sensor model and mouse SAI afferents. The model parameters were iteratively fit against recorded SAI interspike intervals (ISI before validating the model to assess its performance. Results Model-predicted spike firing compares favorably with that observed for single SAI afferents. As indentation magnitude increases (1.2, 1.3, to 1.4 mm, mean ISI decreases from 98.81 ± 24.73, 54.52 ± 6.94, to 41.11 ± 6.11 ms. Moreover, as rate of ramp-up increases, ISI during ramp-up decreases from 21.85 ± 5.33, 19.98 ± 3.10, to 15.42 ± 2.41 ms. Considering first spikes, the predicted latencies exhibited a decreasing trend as stimulus rate increased, as is

  5. Privileged Functional Connectivity between the Visual Word Form Area and the Language System.

    Science.gov (United States)

    Stevens, W Dale; Kravitz, Dwight J; Peng, Cynthia S; Tessler, Michael Henry; Martin, Alex

    2017-05-24

    The visual word form area (VWFA) is a region in the left occipitotemporal sulcus of literate individuals that is purportedly specialized for visual word recognition. However, there is considerable controversy about its functional specificity and connectivity, with some arguing that it serves as a domain-general, rather than word-specific, visual processor. The VWFA is a critical region for testing hypotheses about the nature of cortical organization, because it is known to develop only through experience (i.e., reading acquisition), and widespread literacy is too recent to have influenced genetic determinants of brain organization. Using a combination of advanced fMRI analysis techniques, including individual functional localization, multivoxel pattern analysis, and high-resolution resting-state functional connectivity (RSFC) analyses, with data from 33 healthy adult human participants, we demonstrate that (1) the VWFA can discriminate words from nonword letter strings (pseudowords); (2) the VWFA has preferential RSFC with Wernicke's area and other core regions of the language system; and (3) the strength of the RSFC between the VWFA and Wernicke's area predicts performance on a semantic classification task with words but not other categories of visual stimuli. Our results are consistent with the hypothesis that the VWFA is specialized for lexical processing of real words because of its functional connectivity with Wernicke's area.SIGNIFICANCE STATEMENT The visual word form area (VWFA) is critical for determining the nature of category-related organization of the ventral visual system. However, its functional specificity and connectivity are fiercely debated. Recent work concluded that the VWFA is a domain-general, rather than word-specific, visual processor with no preferential functional connectivity with the language system. Using more advanced techniques, our results stand in stark contrast to these earlier findings. We demonstrate that the VWFA is highly

  6. Visualization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Evaluates and improves the operational effectiveness of existing and emerging electronic warfare systems. By analyzing and visualizing simulation results...

  7. Emulated muscle spindle and spiking afferents validates VLSI neuromorphic hardware as a testbed for sensorimotor function and disease.

    Science.gov (United States)

    Niu, Chuanxin M; Nandyala, Sirish K; Sanger, Terence D

    2014-01-01

    The lack of multi-scale empirical measurements (e.g., recording simultaneously from neurons, muscles, whole body, etc.) complicates understanding of sensorimotor function in humans. This is particularly true for the understanding of development during childhood, which requires evaluation of measurements over many years. We have developed a synthetic platform for emulating multi-scale activity of the vertebrate sensorimotor system. Our design benefits from Very Large Scale Integrated-circuit (VLSI) technology to provide considerable scalability and high-speed, as much as 365× faster than real-time. An essential component of our design is the proprioceptive sensor, or muscle spindle. Here we demonstrate an accurate and extremely fast emulation of a muscle spindle and its spiking afferents, which are computationally expensive but fundamental for reflex functions. We implemented a well-known rate-based model of the spindle (Mileusnic et al., 2006) and a simplified spiking sensory neuron model using the Izhikevich approximation to the Hodgkin-Huxley model. The resulting behavior of our afferent sensory system is qualitatively compatible with classic cat soleus recording (Crowe and Matthews, 1964b; Matthews, 1964, 1972). Our results suggest that this simplified structure of the spindle and afferent neuron is sufficient to produce physiologically-realistic behavior. The VLSI technology allows us to accelerate this behavior beyond 365× real-time. Our goal is to use this testbed for predicting years of disease progression with only a few days of emulation. This is the first hardware emulation of the spindle afferent system, and it may have application not only for emulation of human health and disease, but also for the construction of compliant neuromorphic robotic systems.

  8. Visual Basic Simulated Test System Development%Visual Basic模拟考试系统开发

    Institute of Scientific and Technical Information of China (English)

    潘应晖

    2006-01-01

    根据全国计算机等级考试二级Visual Basic考试特点,利用Visual Basic.NET开发二级Visual Basic模拟考试系统,提出包括数据库操作、数据库中OLE对象数据存取、自动启动Visual Basic应用程序、上机、笔试模拟、复习、数据加密解密等主要模块的解决方法,满足二级Visual Basic学习、训练、模拟考试的自学要求.

  9. A system for visualization and automatic placement of the endoclamp balloon catheter

    Science.gov (United States)

    Furtado, Hugo; Stüdeli, Thomas; Sette, Mauro; Samset, Eigil; Gersak, Borut

    2010-02-01

    The European research network "Augmented Reality in Surgery" (ARIS*ER) developed a system that supports minimally invasive cardiac surgery based on augmented reality (AR) technology. The system supports the surgical team during aortic endoclamping where a balloon catheter has to be positioned and kept in place within the aorta. The presented system addresses the two biggest difficulties of the task: lack of visualization and difficulty in maneuvering the catheter. The system was developed using a user centered design methodology with medical doctors, engineers and human factor specialists equally involved in all the development steps. The system was implemented using the AR framework "Studierstube" developed at TU Graz and can be used to visualize in real-time the position of the balloon catheter inside the aorta. The spatial position of the catheter is measured by a magnetic tracking system and superimposed on a 3D model of the patient's thorax. The alignment is made with a rigid registration algorithm. Together with a user defined target, the spatial position data drives an actuator which adjusts the position of the catheter in the initial placement and corrects migrations during the surgery. Two user studies with a silicon phantom show promising results regarding usefulness of the system: the users perform the placement tasks faster and more accurately than with the current restricted visual support. Animal studies also provided a first indication that the system brings additional value in the real clinical setting. This work represents a major step towards safer and simpler minimally invasive cardiac surgery.

  10. Functional specificity of rat vibrissal primary afferents.

    Science.gov (United States)

    Lucianna, Facundo A; Farfán, Fernando D; Pizá, Gabriel A; Albarracín, Ana L; Felice, Carmelo J

    2016-06-01

    In this study, we propose to analyze the peripheral vibrissal system specificity through its neuronal responses. Receiver operating characteristics (ROC) curve analyses were used, which required the implementation of a binary classifier (artificial neural network) trained to identify the applied stimulus. The training phase consisted of the observation of a predetermined amount of vibrissal sweeps on two surfaces of different texture and similar roughness. Our results suggest that the specificity of the peripheral vibrissal system easily permits the discrimination between perceived stimuli, quantified through neuronal responses, and that it can be evaluated through an ROC curve analysis. We found that such specificity makes a linear binary classifier capable of detecting differences between stimuli with five sweeps at most.

  11. Multivariate Gradient Analysis for Evaluating and Visualizing a Learning System Platform for Computer Programming

    Science.gov (United States)

    Mather, Richard

    2015-01-01

    This paper explores the application of canonical gradient analysis to evaluate and visualize student performance and acceptance of a learning system platform. The subject of evaluation is a first year BSc module for computer programming. This uses "Ceebot," an animated and immersive game-like development environment. Multivariate…

  12. [Image processing system of visual prostheses based on digital signal processor DM642].

    Science.gov (United States)

    Xie, Chengcheng; Lu, Yanyu; Gu, Yun; Wang, Jing; Chai, Xinyu

    2011-09-01

    This paper employed a DSP platform to create the real-time and portable image processing system, and introduced a series of commonly used algorithms for visual prostheses. The results of performance evaluation revealed that this platform could afford image processing algorithms to be executed in real time.

  13. The Effects of Computer Algebra System on Undergraduate Students' Spatial Visualization Skills in a Calculus Course

    Science.gov (United States)

    Karakus, Fatih; Aydin, Bünyamin

    2017-01-01

    This study aimed at determining the effects of using a computer algebra system (CAS) on undergraduate students' spatial visualization skills in a calculus course. This study used an experimental design. The "one group pretest-posttest design" was the research model. The participants were 41 sophomore students (26 female and 15 male)…

  14. Developing a Data Visualization System for the Bank of America Chicago Marathon (Chicago, Illinois USA).

    Science.gov (United States)

    Hanken, Taylor; Young, Sam; Smilowitz, Karen; Chiampas, George; Waskowski, David

    2016-10-01

    As one of the largest marathons worldwide, the Bank of America Chicago Marathon (BACCM; Chicago, Illinois USA) accumulates high volumes of data. Race organizers and engaged agencies need the ability to access specific data in real-time. This report details a data visualization system designed for the Chicago Marathon and establishes key principles for event management data visualization. The data visualization system allows for efficient data communication among the organizing agencies of Chicago endurance events. Agencies can observe the progress of the race throughout the day and obtain needed information, such as the number and location of runners on the course and current weather conditions. Implementation of the system can reduce time-consuming, face-to-face interactions between involved agencies by having key data streams in one location, streamlining communications with the purpose of improving race logistics, as well as medical preparedness and response. Hanken T , Young S , Smilowitz K , Chiampas G , Waskowski D . Developing a data visualization system for the Bank of America Chicago Marathon (Chicago, Illinois USA). Prehosp Disaster Med. 2016;31(5):572-577.

  15. Quality of visual sewer inspection data: The need for a new coding system?! (poster)

    NARCIS (Netherlands)

    Dirksen, J.; Van der Steen, A.; Langeveld, J.G.; Clemens, F.H.L.R.

    2013-01-01

    Previous research learned that the reproducibility of visual sewer inspection data is poor (Dirksen et al.). Further research by Arjan et al. showed that the applied coding system has a major influence on the reproducibility. The aim of this study was to give relevant suggestions to improve the qual

  16. Multiscale aspects of the visual system and their use for scale invariant object recognition

    NARCIS (Netherlands)

    Petkov, N; vanDeemter, J; Karsch, F; Monien, B; Satz, H

    1997-01-01

    Psychophysical, neuroanatomical and neurophysiological evidence for multiscale aspects of the visual system is considered. The stack model and its relation to the image pyramid are discussed. The results of a straightforward implementation on a parallel supercomputer are presented. The high computat

  17. Text Detection from Natural Scene Images : Towards a System for Visually Impaired Persons

    NARCIS (Netherlands)

    Ezaki, Nobuo; Bulacu, Marius; Schomaker, Lambert

    2004-01-01

    We propose a system that reads the text encountered in natural scenes with the aim to provide assistance to the visually impaired persons. This paper describes the sys- tem design and evaluates several character extraction meth- ods. Automatic text recognition from natural images re- ceives a growin

  18. Comparison of the pattern reversal visual evoked potential mediated by separate cone systems

    DEFF Research Database (Denmark)

    Johnsen, B; Frederiksen, J.L.; Larsson, H.B.

    1995-01-01

    With the purpose of recording responses mediated by the 3 cone systems visual evoked potentials (VEPs) were elicited by the reversal of monochromatic checkerboards superimposed upon strong monochromatic backgrounds (yellow, purple and blue-green). The sensitivity to light of various wave lengths...

  19. Using the Picture Exchange Communication System with Students with Visual Impairment

    Science.gov (United States)

    Ivy, Sarah E.; Hatton, Deborah D.; Hooper, Jonathan D.

    2014-01-01

    Students with visual impairment (VI) were taught to request using the Picture Exchange Communication System (PECS) and tangible symbols. Participants were four males with additional disabilities, 5 to 11 years old, who had little to no functional vision. A functional relation between PECS Phase 1 and requesting was established using a multiple…

  20. A Mobile Personal Informatics System with Interactive Visualizations of Mobility and Social Interactions

    DEFF Research Database (Denmark)

    Cuttone, Andrea; Jørgensen, Sune Lehmann; Larsen, Jakob Eg

    2013-01-01

    We describe a personal informatics system for Android smartphones that provides personal data on mobility and social interactions through interactive visualization interfaces. The mobile app has been made available to N=136 first year university students as part of a study of social network...