Effects of listening to pleasant music on chronic unilateral neglect: a single-subject study.

PubMed

Tsai, Pei-Luen; Chen, Mei-Ching; Huang, Yu-Ting; Lin, Keh-Chung

2013-01-01

Recent studies suggest that the positive emotion induced by pleasant music may improve cognitive functions. We used the single-subject design to study whether listening to preferred music may reduce unilateral neglect in two participants with post-stroke neglect. These participants were instructed to listen to their preferred music every day for 5 weeks, followed by 2 weeks of follow-up assessment. Outcome measures involved the Star Cancellation Test, the Line Bisection Test, and the visual exploration task. A combination of visual analysis and the two-standard-deviation band method was used for data analysis. Both participants showed significant intervention-related improvements on all outcome measures except the Line Bisection Test, on which one participant showed no improvement. The therapeutic effects were maintained during the follow-up phase. The findings suggest that positive emotion, evoked by preferred music, may be used to ameliorate unilateral neglect. Further research using controlled trials is warranted to validate the findings.

Radial bisection of words and lines in right-brain-damaged patients with spatial neglect.

PubMed

Veronelli, Laura; Arduino, Lisa S; Girelli, Luisa; Vallar, Giuseppe

2017-09-01

The bisection of lines positioned radially (with the two ends of the line close and far, with respect to the participant's body) has been less investigated than that of lines placed horizontally (with their two ends left and right, with respect to the body's midsagittal plane). In horizontal bisection, patients with left neglect typically show a rightward bias for both lines and words, greater with longer stimuli. As for radial bisection, available data indicate that neurologically unimpaired participants make a distal error, while results from right-brain-damaged patients with left spatial neglect are contradictory. We investigated the bisection of radially oriented words, with the prediction that, during bisection, linguistic material would be recoded to its canonical left-to-right format in reading, with the performance of neglect patients being similar to that for horizontal words. Thirteen right-brain-damaged patients (seven with left spatial neglect) and fourteen healthy controls were asked to manually bisect 40 radial and 40 horizontal words (5-10 letters), and 80 lines, 40 radial and 40 horizontal, of comparable length. Right-brain-damaged patients with spatial neglect exhibited a proximal bias in the bisection of short radial words, with the proximal part corresponding to the final right part of horizontally oriented words. This proximal error was not found in patients without neglect and healthy controls. For bisection, short radial words may be recoded to the canonical orthographic horizontal format, unveiling the impact of left neglect on radially oriented stimuli. © 2015 The British Psychological Society.

Perceptual-Attentional and Motor-Intentional Bias in Near and Far Space

PubMed Central

Garza, John P.; Eslinger, Paul J.; Barrett, Anna M.

2008-01-01

Spatial bias demonstrated in tasks such as line-bisection may stem from perceptual-attentional (PA) “where” and motor-intentional (MI) “aiming” influences. We tested normal participants’ line bisection performance in the presence of an asymmetric visual distracter with a video apparatus designed to dissociate PA from MI bias. An experimenter stood as a distractor to the left or right of a video monitor positioned in either near or far space, where participants viewed lines and a laser point they directed under 1) natural and 2) mirror-reversed conditions. Each trial started with the pointer positioned at either the top left or top right corner of the screen, and alternated thereafter. Data analysis indicated that participants made primarily PA leftward errors in near space, but not in far space. Furthermore, PA, but not MI, bias increased bilaterally in the direction of distraction. In contrast, MI, but not PA, bias was shifted bilaterally in the direction of startside. Results support the conclusion that a primarily PA left sided bias in near space is consistent with right hemisphere spatial attentional dominance. A bottom-up visual distractor specifically affected PA “where” spatial bias while top-down motor cuing influenced MI “aiming” bias. PMID:18381226

Line-Bisecting Performance in Highly Skilled Athletes: Does Preponderance of Rightward Error Reflect Unique Cortical Organization and Functioning?

ERIC Educational Resources Information Center

Carlstedt, Roland A.

2004-01-01

A line-bisecting test was administered to 250 highly skilled right-handed athletes and a control group of 60 right-handed age matched non-athletes. Results revealed that athletes made overwhelmingly more rightward errors than non-athletes, who predominantly bisected lines to the left of the veridical center. These findings were interpreted in the…

The Centre Is Not in the Middle: Evidence from Line and Word Bisection

ERIC Educational Resources Information Center

Arduino, Lisa S.; Previtali, Paola; Girelli, Luisa

2010-01-01

English and German readers have been shown to mark a position to the left of the true centre as the subjective midpoint in word bisection. This effect resembles a well-known phenomenon observed with the bisection of solid lines (pseudoneglect), although this behavioural similarity does not imply a common origin. The purpose of the present study…

Prism adaptation magnitude has differential influences on perceptual versus manual responses.

PubMed

Striemer, Christopher L; Russell, Karyn; Nath, Priya

2016-10-01

Previous research has indicated that rightward prism adaptation can reduce symptoms of spatial neglect following right brain damage. In addition, leftward prism adaptation can create "neglect-like" patterns of performance in healthy adults on tasks that measure attention and spatial biases. Although a great deal of research has focused on which behaviors are influenced by prism adaptation, very few studies have focused directly on how the magnitude of visual shift induced by prisms might be related to the observed aftereffects, or the effects of prisms on measures of attentional and spatial biases. In the current study, we examined these questions by having groups of healthy adult participants complete manual line bisection and landmark tasks prior to and following adaptation to either 8.5° (15 diopter; n = 22) or 17° (30 diopter; n = 25) leftward shifting prisms. Our results demonstrated a significantly larger rightward shift in straight-ahead pointing (a measure of prism aftereffect) following adaptation to 17°, compared to 8.5° leftward shifting prisms. In addition, only 17° leftward shifting prisms resulted in a significant rightward shift in line bisection following adaptation. However, there was a significant change in performance on the landmark task pre- versus post-adaptation in both the 8.5° and 17° leftward shifting prism groups. Interestingly, correlation analyses indicated that changes in straight-ahead pointing pre- versus post-adaptation were positively correlated with changes in performance on the manual line bisection task, but not the landmark task. These data suggest that larger magnitudes of prism adaptation seem to have a greater influence on tasks that require a response with the adapted hand (i.e., line bisection), compared to tasks that only require a perceptual judgment (i.e., the landmark task). In addition, these data provide further evidence that the effects of prisms on manual and perceptual responses are not related to one another.

Combining language and space: sentence bisection in unilateral spatial neglect.

PubMed

Veronelli, Laura; Guasti, Maria T; Arduino, Lisa S; Vallar, Giuseppe

2014-10-01

In line bisection right-brain-damaged patients with left spatial neglect show a rightward deviation, with respect to the line's physical center. In word bisection ortho-phonological features of the stimulus' final (right-sided) part modulate performance of both patients and healthy participants (Veronelli, Vallar, Marinelli, Primativo, & Arduino, 2014). We investigated the role of linguistic factors in sentence bisection, in patients with and without neglect, and control participants. The effects of information in the right-sided part of the sentence (Experiment #1), and of lexical and syntactic violations (Experiment #2) were assessed. Neglect patients showed an overall rightward bias, larger than those of patients without neglect and controls. The neglect patients' bias was modulated by stimulus type, decreasing from lines, to letter strings and to all types of sentences. In sum, in visuo-manual sentence bisection a basic linguistic mechanism, such as sentence readability, brings about a more leftward appreciation of the stimulus, reducing the neglect patients' rightward bias. Copyright © 2014 Elsevier Inc. All rights reserved.

Auditory/visual Duration Bisection in Patients with Left or Right Medial-Temporal Lobe Resection

ERIC Educational Resources Information Center

Melgire, Manuela; Ragot, Richard; Samson, Severine; Penney, Trevor B.; Meck, Warren H.; Pouthas, Viviane

2005-01-01

Patients with unilateral (left or right) medial temporal lobe lesions and normal control (NC) volunteers participated in two experiments, both using a duration bisection procedure. Experiment 1 assessed discrimination of auditory and visual signal durations ranging from 2 to 8 s, in the same test session. Patients and NC participants judged…

Early Visual Deprivation Severely Compromises the Auditory Sense of Space in Congenitally Blind Children

ERIC Educational Resources Information Center

Vercillo, Tiziana; Burr, David; Gori, Monica

2016-01-01

A recent study has shown that congenitally blind adults, who have never had visual experience, are impaired on an auditory spatial bisection task (Gori, Sandini, Martinoli, & Burr, 2014). In this study we investigated how thresholds for auditory spatial bisection and auditory discrimination develop with age in sighted and congenitally blind…

Non-musicians also have a piano in the head: evidence for spatial-musical associations from line bisection tracking.

PubMed

Hartmann, Matthias

2017-02-01

The spatial representation of ordinal sequences (numbers, time, tones) seems to be a fundamental cognitive property. While an automatic association between horizontal space and pitch height (left-low pitch, right-high pitch) is constantly reported in musicians, the evidence for such an association in non-musicians is mixed. In this study, 20 non-musicians performed a line bisection task while listening to irrelevant high- and low-pitched tones and white noise (control condition). While pitch height had no influence on the final bisection point, participants' movement trajectories showed systematic biases: When approaching the line and touching the line for the first time (initial bisection point), the mouse cursor was directed more rightward for high-pitched tones compared to low-pitched tones and noise. These results show that non-musicians also have a subtle but nevertheless automatic association between pitch height and the horizontal space. This suggests that spatial-musical associations do not necessarily depend on constant sensorimotor experiences (as it is the case for musicians) but rather reflect the seemingly inescapable tendency to represent ordinal information on a horizontal line.

Visuospatial biases in preschool children: Evidence from line bisection in three-dimensional space.

PubMed

Patro, Katarzyna; Nuerk, Hans-Christoph; Brugger, Peter

2018-04-09

Spatial attention in adults is characterized by systematic asymmetries across all three spatial dimensions. These asymmetries are evident when participants bisect horizontal, vertical, or radial lines and misplace their midpoints to the left, the top, or far from the body, respectively. However, bisection errors are rarely examined during early childhood. In this study, we examined the development of spatial-attentional asymmetries in three-dimensional (3D) space by asking preschool children (aged 3-6 years) to bisect horizontal, vertical, and radial lines. Children erred to the left with horizontal lines and to the top with vertical lines, consistent with the pattern reported in adults. These biases got stronger with age and were absent in the youngest preschoolers. However, by controlling for a possible failure in hitting the line, we observed an additional unpredicted pattern: Children's pointing systematically deviated away from the line to an empty space on its left side (for vertical and radial lines) or above it (for horizontal lines). Notably, this task-irrelevant deviation was pronounced in children as young as 3 or 4 years. We conclude that asymmetries in spatial-attentional functions should be measured not only in task-relevant dimensions but also in task-irrelevant dimensions because the latter may reveal biases in very young children not typically observed in task-relevant measures. Copyright © 2018 Elsevier Inc. All rights reserved.

Lateral Biases and Reading Direction: A Dissociation between Aesthetic Preference and Line Bisection

ERIC Educational Resources Information Center

Ishii, Yukiko; Okubo, Matia; Nicholls, Michael E. R.; Imai, Hisato

2011-01-01

Perceptual asymmetries for tasks involving aesthetic preference or line bisection can be affected by asymmetrical neurological mechanisms or left/right reading habits. This study investigated the relative contribution of these mechanisms in 100 readers of Japanese and English. Participants made aesthetic judgments between pairs of mirror-reversed…

Right up There: Hemispatial and Hand Asymmetries of Altitudinal Pseudoneglect

ERIC Educational Resources Information Center

Suavansri, Ketchai; Falchook, Adam D.; Williamson, John B.; Heilman, Kenneth M.

2012-01-01

Background: Pseudoneglect is a normal left sided spatial bias observed with attempted bisections of horizontal lines and a normal upward bias observed with attempted bisections of vertical lines. Horizontal pseudoneglect has been attributed to right hemispheric dominance for the allocation of attention. The goal of this study was to test the…

The influence of unimanual response on pseudoneglect magnitude.

PubMed

McCourt, M E; Freeman, P; Tahmahkera-Stevens, C; Chaussee, M

2001-02-01

Various factors influence the degree of leftward error (pseudoneglect) (Bowers & Heilman, 1980) that typifies the performance of normal subjects in line bisection tasks (Jewell & McCourt, 2000). The results of this experiment show that unimanual responding also exerts a subtle but significant modulating influence on spatial attention, as indexed by the differential magnitude of pseudoneglect. Using a forced-choice tachistoscopic line bisection protocol, 184 subjects (92 male and 92 female) bisected horizontally oriented lines (22.3 degrees wide x 0.39 degrees height) presented to central vision in two conditions, in which bisection responses were executed via button presses using the first two fingers of either the left (LH) or right (RH) hand. Perceived line midpoint deviated significantly leftward of veridical (p <.05) in both conditions. There was no significant influence of subject sex (p >.05). A significant influence of unimanual response was revealed (p <.05) where pseudoneglect magnitude was greater in the LH than the RH condition. The results are interpreted within the framework of the activation-orientation theory of attentional asymmetry. Copyright 2001 Academic Press.

Normative data for distal line bisection and baking tray task.

PubMed

Facchin, Alessio; Beschin, Nicoletta; Pisano, Alessia; Reverberi, Cristina

2016-09-01

Line bisection is one of the tests used to diagnose unilateral spatial neglect (USN). Despite its wide application, no procedure or norms were available for the distal variant when the task was performed at distance with a laser pointer. Furthermore, the baking tray task was an ecological test aimed at diagnosing USN in a more natural context. The aim of this study was to collect normative values for these two tests in an Italian population. We recruited a sample of 191 healthy subjects with ages ranging from 20 to 89 years. They performed line bisection with a laser pointer on three different line lengths (1, 1.5, and 2 m) at a distance of 3 m. After this task, the subjects performed the baking tray task and a second repetition of line bisection to test the reliability of measurement. Multiple regression analysis revealed no significant effects of demographic variables on the performance of both tests. Normative cut-off values for the two tests were developed using non-parametric tolerance intervals. The results formed the basis for clinical use of these two tools for assessing lateralized performance of patients with brain injury and for diagnosing USN.

Great Dike of Zimbabwe, Zimbabwae, Africa

NASA Technical Reports Server (NTRS)

1993-01-01

The Great Dike of Zimbabwe (17.5S, 31.5E) bisects the entire length of Zimbabwae in southern Africa and is one of the prominent visual features easily recognized from low orbit. The volcanic rocks which make up the dike are about 1.2 billion years old and are rich in chromite and platinum which are mined from it. The straight line of the dike is offset in places by faults which are often occupied by streams flowing through the fractures.

Decreased Leftward ‘Aiming’ Motor-Intentional Spatial Cuing in Traumatic Brain Injury

PubMed Central

Wagner, Daymond; Eslinger, Paul J.; Barrett, A. M.

2016-01-01

Objective To characterize the mediation of attention and action in space following traumatic brain injury (TBI). Method Two exploratory analyses were performed to determine the influence of spatial ‘Aiming’ motor versus spatial ‘Where’ bias on line bisection in TBI participants. The first experiment compared performance according to severity and location of injury in TBI. The second experiment examined bisection performance in a larger TBI sample against a matched control group. In both experiments, participants bisected lines in near and far space using an apparatus that allowed for the fractionation of spatial Aiming versus Where error components. Results In the first experiment, participants with severe injuries tended to incur rightward error when starting from the right in far space, compared with participants with mild injuries. In the second experiment, when performance was examined at the individual level, more participants with TBI tended to incur rightward motor error compared to controls. Conclusions TBI may cause frontal-subcortical cognitive dysfunction and asymmetric motor perseveration, affecting spatial Aiming bias on line bisection. Potential effects on real-world function need further investigation. PMID:27571220

Feasibility of a Semi-computerized Line Bisection Test for Unilateral Visual Neglect Assessment.

PubMed

Jee, H; Kim, J; Kim, C; Kim, T; Park, J

2015-01-01

Commonly used paper-and-pencil based test modalities for assessing the degree of unilateral visual neglect (ULN) in patients with hemispheric cerebral lesions consume human resources with a significant inter and intra-rater variability. To explore the feasibility of a semi-computerized electronic-pen based ULN assessment system (e-system) to improve assessment quality without altering the conventional user interface. Thirty cognitively healthy participants (HG) and 11 participants diagnosed with right-hemispheric lesion and unilateral visual neglect (NG) were recruited to evaluate the e-system. Line bisection tests (LBT) were repeatedly conducted twice for the inter-rater and intra-rater (reliability) comparisons. The LBT results were assessed by the e-system and the golden standard methods (manual rater assessment). The percent deviation (%), assessment duration (sec), and number of neglected line (each) were evaluated. The inter-rater comparisons of the assessed deviation (%) variable showed excellent interrater reliabilities (CCCs) ranging from .84 (.59 to .95 (p < .001)) to .99 (.90 to .99 (p < .001)) for HG and NG. The Bland Altman mean difference (B-A) plots with bias (95% LOA (limits of agreement)) showed similar agreements between the e-system and the raters ranging from -.04 % (-2.10 to 1.97) to 1.30 % (-2.23 to 4.84) for HG and NG. The effect sizes (ES), which show similarities between the assessment methods, yielded smaller ranges from .01 to .30 for HG and NG. The reliability (test-retest) comparisons showed similar assessment results between the e-system, rater 1, and rater 2. The manual rater assessment time ranging from 5.85 to 6.00 minutes and inter- and intraassessment variations were virtually eliminated with the e-system. The semi-computerized system with the conventional paper-and pencil user-interface showed valid and reliable assessment results. It may be a feasible replacement for the manual rater assessment modality even in a clinical setting.

Line and word bisection in right-brain-damaged patients with left spatial neglect.

PubMed

Veronelli, Laura; Vallar, Giuseppe; Marinelli, Chiara V; Primativo, Silvia; Arduino, Lisa S

2014-01-01

Right-brain-damaged patients with left unilateral spatial neglect typically set the mid-point of horizontal lines to the right of the objective center. By contrast, healthy participants exhibit a reversed bias (pseudoneglect). The same effect has been described also when bisecting orthographic strings. In particular, for this latter kind of stimulus, some recent studies have shown that visuo-perceptual characteristics, like stimulus length, may contribute to both the magnitude and the direction bias of the bisection performance (Arduino et al. in Neuropsychologia 48:2140-2146, 2010). Furthermore, word stress was shown to modulate reading performances in both healthy participants, and patients with left spatial neglect and neglect dyslexia (Cubelli and Beschin in Brain Lang 95:319-326, 2005; Rusconi et al. in Neuropsychology 18:135-140, 2004). In Experiment I, 22 right-brain-damaged patients (11 with left visuo-spatial neglect) and 11 matched neurologically unimpaired control participants were asked to set the subjective mid-point of word letter strings, and of lines of comparable length. Most patients exhibited an overall disproportionate rightward bias, sensitive to stimulus length, and similar for words and lines. Importantly, in individual patients, biases differed according to stimulus type (words vs. lines), indicating that at least partly different mechanisms may be involved. In Experiment II, the putative effects on the bisection bias of ortho-phonological information (i.e., word stress endings), arising from the non-neglected right hand side of the stimulus were investigated. The orthographic cue induced a rightward shift of the perceived mid-point in both patients and controls, with short words stressed on the antepenultimate final sequence inducing a smaller rightward deviation with respect to short words stressed on the penultimate final sequence. In conclusion, partly different mechanisms, including both visuo-spatial and lexical factors, may support line and word bisection performance of right-brain-damaged patients with left spatial neglect, and healthy participants.

Memory for Spatial Locations in a Patient with Near Space Neglect and Optic Ataxia: Involvement of the Occipitotemporal Stream

PubMed Central

Chieffi, Sergio; Messina, Giovanni; Messina, Antonietta; Villano, Ines; Monda, Vincenzo; Ambra, Ferdinando Ivano; Garofalo, Elisabetta; Romano, Felice; Mollica, Maria Pina; Monda, Marcellino; Iavarone, Alessandro

2017-01-01

Previous studies suggested that the occipitoparietal stream orients attention toward the near/lower space and is involved in immediate reaching, whereas the occipitotemporal stream orients attention toward the far/upper space and is involved in delayed reaching. In the present study, we investigated the role of the occipitotemporal stream in attention orienting and delayed reaching in a patient (GP) with bilateral damage to the occipitoparietal areas and optic ataxia. GP and healthy controls took part in three experiments. In the experiment 1, the participants bisected lines oriented along radial, vertical, and horizontal axes. GP bisected radial lines farther, and vertical lines more above, than the controls, consistent with an attentional bias toward the far/upper space and near/lower space neglect. The experiment 2 consisted of two tasks: (1) an immediate reaching task, in which GP reached target locations under visual control and (2) a delayed visual reaching task, in which GP and controls were asked to reach remembered target locations visually presented. We measured constant and variable distance and direction errors. In immediate reaching task, GP accurately reached target locations. In delayed reaching task, GP overshot remembered target locations, whereas the controls undershot them. Furthermore, variable errors were greater in GP than in the controls. In the experiment 3, GP and controls performed a delayed proprioceptive reaching task. Constant reaching errors did not differ between GP and the controls. However, variable direction errors were greater in GP than in the controls. We suggest that the occipitoparietal damage, and the relatively intact occipitotemporal region, produced in GP an attentional orienting bias toward the far/upper space (experiment 1). In turns, the attentional bias selectively shifted toward the far space remembered visual (experiment 2), but not proprioceptive (experiment 3), target locations. As a whole, these findings further support the hypothesis of an involvement of the occipitotemporal stream in delayed reaching. Furthermore, the observation that in both delayed reaching tasks the variable errors were greater in GP than in the controls suggested that in optic ataxia is present not only a visuo- but also a proprioceptivo-motor integration deficit. PMID:28620345

Effects of stimulant medication on the lateralisation of line bisection judgements of children with attention deficit hyperactivity disorder.

PubMed

Sheppard, D M; Bradshaw, J L; Mattingley, J B; Lee, P

1999-01-01

Deficits in the maintenance of attention may underlie problems in attention deficit hyperactivity disorder (ADHD). Children with ADHD also show asymmetric attention deficits in traditional lateralisation and visuospatial orienting tasks, suggesting right hemispheric (and left hemispace) attentional disturbance. This study aimed to examine the lateralisation of selective attention in ADHD; specifically, the effect of a moving, random dot background, and stimulant medication in the line bisection task. The performance of children with ADHD, on and off methylphenidate, was examined using a computerised horizontal line bisection task with moving and blank backgrounds. Twenty children with a DSM-IV diagnosis of ADHD participated with 20 controls, individually matched for age, sex, grade at school, and IQ. Twelve of the 20 children with ADHD were on stimulant medication at the time of testing. Horizontal lines of varying length were presented in the centre of a computer screen, with either a blank background, or a moving, random dot field. The random dots moved either leftward or rightward across the screen at either 40 mm/s or 80 mm/s. The children with ADHD off medication bisected lines significantly further to the right compared with controls, who showed a small leftward error. Methylphenidate normalised the performance of the children with ADHD for the task with the moving dots. These results support previous evidence for a right hemispheric hypoarousal theory of attentional dysfunction, and are consistent with the emerging picture of a lateralised dysfunction of frontostriatal circuitry in ADHD.

Peripersonal and extrapersonal visuospatial neglect in different frames of reference: A brain lesion-symptom mapping study.

PubMed

Ten Brink, Antonia F; Matthijs Biesbroek, J; Oort, Quirien; Visser-Meily, Johanna M A; Nijboer, Tanja C W

2018-06-22

Visuospatial neglect can occur in peripersonal and extrapersonal space. The dorsal visual pathway is hypothesized to be associated with peripersonal, and the ventral pathway with extrapersonal neglect. We aimed to evaluate neural substrates of peripersonal versus extrapersonal neglect, separately for egocentric and allocentric frames of reference. This was a retrospective study, including stroke patients admitted for inpatient rehabilitation. Approximately 1 month post-stroke onset, computerized cancellation (egocentric) and bisection tasks (egocentric and allocentric) were administered at 30 cm and 120 cm. We collected CT or MRI scans and performed voxel-based lesion-symptom mapping for the cancellation, and subtraction analyses for the line bisection task. We included 98 patients for the cancellation and 129 for the bisection analyses. The right parahippocampal gyrus, hippocampus, and thalamus were associated with egocentric peripersonal neglect as measured with cancellation. These areas were also associated with extrapersonal neglect, together with the right superior parietal lobule, angular gyrus, supramarginal gyrus, lateral occipital cortex, planum temporale and superior temporal gyrus. Lesions in the right parietal, temporal and frontal areas were associated with both peripersonal and extrapersonal egocentric neglect as measured with bisection. For allocentric neglect no clear pattern of associated brain regions was observed. We found right hemispheric anatomical correlates for peripersonal and extrapersonal neglect. However, no brain areas were uniquely associated with peripersonal neglect, meaning we could not conclusively verify the ventral/dorsal hypothesis. Several areas were uniquely associated with egocentric extrapersonal neglect, suggesting that these brain areas can be specifically involved in extrapersonal, but not in peripersonal, attention processes. Copyright © 2018. Published by Elsevier B.V.

Audio-visual temporal perception in children with restored hearing.

PubMed

Gori, Monica; Chilosi, Anna; Forli, Francesca; Burr, David

2017-05-01

It is not clear how audio-visual temporal perception develops in children with restored hearing. In this study we measured temporal discrimination thresholds with an audio-visual temporal bisection task in 9 deaf children with restored audition, and 22 typically hearing children. In typically hearing children, audition was more precise than vision, with no gain in multisensory conditions (as previously reported in Gori et al. (2012b)). However, deaf children with restored audition showed similar thresholds for audio and visual thresholds and some evidence of gain in audio-visual temporal multisensory conditions. Interestingly, we found a strong correlation between auditory weighting of multisensory signals and quality of language: patients who gave more weight to audition had better language skills. Similarly, auditory thresholds for the temporal bisection task were also a good predictor of language skills. This result supports the idea that the temporal auditory processing is associated with language development. Copyright © 2017. Published by Elsevier Ltd.

Order information in verbal working memory shifts the subjective midpoint in both the line bisection and the landmark tasks.

PubMed

Antoine, Sophie; Ranzini, Mariagrazia; Gebuis, Titia; van Dijck, Jean-Philippe; Gevers, Wim

2017-10-01

A largely substantiated view in the domain of working memory is that the maintenance of serial order is achieved by generating associations of each item with an independent representation of its position, so-called position markers. Recent studies reported that the ordinal position of an item in verbal working memory interacts with spatial processing. This suggests that position markers might be spatial in nature. However, these interactions were so far observed in tasks implying a clear binary categorization of space (i.e., with left and right responses or targets). Such binary categorizations leave room for alternative interpretations, such as congruency between non-spatial categorical codes for ordinal position (e.g., begin and end) and spatial categorical codes for response (e.g., left and right). Here we discard this interpretation by providing evidence that this interaction can also be observed in a task that draws upon a continuous processing of space, the line bisection task. Specifically, bisections are modulated by ordinal position in verbal working memory, with lines bisected more towards the right after retrieving items from the end compared to the beginning of the memorized sequence. This supports the idea that position markers are intrinsically spatial in nature.

The effect of virtual reality training on unilateral spatial neglect in stroke patients.

PubMed

Kim, Yong Mi; Chun, Min Ho; Yun, Gi Jeong; Song, Young Jin; Young, Han Eun

2011-06-01

To investigate the effect of virtual reality training on unilateral spatial neglect in stroke patients. Twenty-four stroke patients (14 males and 10 females, mean age=64.7) who had unilateral spatial neglect as a result of right hemisphere stroke were recruited. All patients were randomly assigned to either the virtual reality (VR) group (n=12) or the control group (n=12). The VR group received VR training, which stimulated the left side of their bodies. The control group received conventional neglect therapy such as visual scanning training. Both groups received therapy for 30 minutes a day, five days per week for three weeks. Outcome measurements included star cancellation test, line bisection test, Catherine Bergego scale (CBS), and the Korean version of modified Barthel index (K-MBI). These measurements were taken before and after treatment. There were no significant differences in the baseline characteristics and initial values between the two groups. The changes in star cancellation test results and CBS in the VR group were significantly higher than those of the control group after treatment. The changes in line bisection test score and the K-MBI in the VR group were not statistically significant. This study suggests that virtual reality training may be a beneficial therapeutic technique on unilateral spatial neglect in stroke patients.

Differences in paper-and-pencil versus computerized line bisection according to ADHD subtype and hand-use.

PubMed

Rolfe, Mei Hsin Suzanne; Hamm, Jeff P; Waldie, Karen E

2008-03-01

Two versions of the line bisection task, paper-and-pencil and computerized, were administered to non-medicated children (5-12 years) with and without Attention-Deficit/Hyperactivity Disorder (ADHD). Fifteen children were classified with ADHD-Inattentive type (ADHD-I), 15 were classified with ADHD-Combined or Hyperactive-Impulsive type (ADHD-C), and 15 children served as controls. During the paper-and-pencil task, and irrespective of hand-use, participants with ADHD-C bisected lines with a right bias, whereas participants with ADHD-I showed a leftwards bias. Interestingly, during the computerized version, an opposite pattern of hemineglect was observed with a leftwards bias for participants with ADHD-C and a rightwards bias for participants with ADHD-I. These findings suggest that different task demands are associated with the paper-and-pencil and computerized tasks. The findings also suggest that the two subtypes differ according to their cognitive profile, and possibly differ as to their underlying neural impairment.

Non-spatial neglect for the mental number line.

PubMed

van Dijck, Jean-Philippe; Gevers, Wim; Lafosse, Christophe; Doricchi, Fabrizio; Fias, Wim

2011-07-01

Several psychophysical investigations, expanding the classical introspective observations by Galton, have suggested that the mental representation of numbers takes the form of a number line along which magnitude is positioned in ascending order according to reading habits, i.e. from left to right in Western cultures. In keeping with the evidence, pathological rightward deviations in the bisection of number intervals due to right brain damage are generally interpreted as originating from a purely spatial-attentional deficit in the processing of the left side of number intervals. However, consistent double dissociations between defective processing of the left side of physical and mental number space have called into question the universality of this interpretation. Recent evidence suggests a link between rightward deviations in number space and defective memory for both spatial and non-spatial sequences of items. Here we describe the case of a left brain-damaged patient exhibiting right-sided neglect for extrapersonal and representational space, and left-sided neglect on the mental number line. Accurate neuropsychological examination revealed that the apparent left-sided neglect in the bisection of number intervals had a purely non-spatial origin and was based on mnemonic difficulties for the initial items of verbal sequences presented visually at an identical spatial position. These findings show that effective position-based verbal working memory might be crucial for numerical tasks that are usually considered to involve purely spatial representation of numerical magnitudes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Prism adaptation and neck muscle vibration in healthy individuals: are two methods better than one?

PubMed

Guinet, M; Michel, C

2013-12-19

Studies involving therapeutic combinations reveal an important benefit in the rehabilitation of neglect patients when compared to single therapies. In light of these observations our present work examines, in healthy individuals, sensorimotor and cognitive after-effects of prism adaptation and neck muscle vibration applied individually or simultaneously. We explored sensorimotor after-effects on visuo-manual open-loop pointing, visual and proprioceptive straight-ahead estimations. We assessed cognitive after-effects on the line bisection task. Fifty-four healthy participants were divided into six groups designated according to the exposure procedure used with each: 'Prism' (P) group; 'Vibration with a sensation of body rotation' (Vb) group; 'Vibration with a move illusion of the LED' (Vl) group; 'Association with a sensation of body rotation' (Ab) group; 'Association with a move illusion of the LED' (Al) group; and 'Control' (C) group. The main findings showed that prism adaptation applied alone or combined with vibration showed significant adaptation in visuo-manual open-loop pointing, visual straight-ahead and proprioceptive straight-ahead. Vibration alone produced significant after-effects on proprioceptive straight-ahead estimation in the Vl group. Furthermore all groups (except C group) showed a rightward neglect-like bias in line bisection following the training procedure. This is the first demonstration of cognitive after-effects following neck muscle vibration in healthy individuals. The simultaneous application of both methods did not produce significant greater after-effects than prism adaptation alone in both sensorimotor and cognitive tasks. These results are discussed in terms of transfer of sensorimotor plasticity to spatial cognition in healthy individuals. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

The Effect of Virtual Reality Training on Unilateral Spatial Neglect in Stroke Patients

PubMed Central

Kim, Yong Mi; Yun, Gi Jeong; Song, Young Jin; Young, Han Eun

2011-01-01

Objective To investigate the effect of virtual reality training on unilateral spatial neglect in stroke patients. Method Twenty-four stroke patients (14 males and 10 females, mean age=64.7) who had unilateral spatial neglect as a result of right hemisphere stroke were recruited. All patients were randomly assigned to either the virtual reality (VR) group (n=12) or the control group (n=12). The VR group received VR training, which stimulated the left side of their bodies. The control group received conventional neglect therapy such as visual scanning training. Both groups received therapy for 30 minutes a day, five days per week for three weeks. Outcome measurements included star cancellation test, line bisection test, Catherine Bergego scale (CBS), and the Korean version of modified Barthel index (K-MBI). These measurements were taken before and after treatment. Results There were no significant differences in the baseline characteristics and initial values between the two groups. The changes in star cancellation test results and CBS in the VR group were significantly higher than those of the control group after treatment. The changes in line bisection test score and the K-MBI in the VR group were not statistically significant. Conclusion This study suggests that virtual reality training may be a beneficial therapeutic technique on unilateral spatial neglect in stroke patients. PMID:22506138

Eye-Tracking Reveals that the Strength of the Vertical-Horizontal Illusion Increases as the Retinal Image Becomes More Stable with Fixation

PubMed Central

Chouinard, Philippe A.; Peel, Hayden J.; Landry, Oriane

2017-01-01

The closer a line extends toward a surrounding frame, the longer it appears. This is known as a framing effect. Over 70 years ago, Teodor Künnapas demonstrated that the shape of the visual field itself can act as a frame to influence the perceived length of lines in the vertical-horizontal illusion. This illusion is typically created by having a vertical line rise from the center of a horizontal line of the same length creating an inverted T figure. We aimed to determine if the degree to which one fixates on a spatial location where the two lines bisect could influence the strength of the illusion, assuming that the framing effect would be stronger when the retinal image is more stable. We performed two experiments: the visual-field and vertical-horizontal illusion experiments. The visual-field experiment demonstrated that the participants could discriminate a target more easily when it was presented along the horizontal vs. vertical meridian, confirming a framing influence on visual perception. The vertical-horizontal illusion experiment determined the effects of orientation, size and eye gaze on the strength of the illusion. As predicted, the illusion was strongest when the stimulus was presented in either its standard inverted T orientation or when it was rotated 180° compared to other orientations, and in conditions in which the retinal image was more stable, as indexed by eye tracking. Taken together, we conclude that the results provide support for Teodor Künnapas’ explanation of the vertical-horizontal illusion. PMID:28392764

Orientation of X Lines in Asymmetric Magnetic Reconnection-Mass Ratio Dependency

NASA Technical Reports Server (NTRS)

Liu, Yi-Hsin; Hesse, M.; Kuznetsova, M.

2015-01-01

Using fully kinetic simulations, we study the X line orientation of magnetic reconnection in an asymmetric configuration. A spatially localized perturbation is employed to induce a single X line, which has sufficient freedom to choose its orientation in three-dimensional systems. The effect of ion to electron mass ratio is investigated, and the X line appears to bisect the magnetic shear angle across the current sheet in the large mass ratio limit. The orientation can generally be deduced by scanning through the corresponding 2-D simulations to find the reconnection plane that maximizes the peak reconnection electric field. The deviation from the bisection angle in the lower mass ratio limit is consistent with the orientation shift of the most unstable linear tearing mode in an electron-scale current sheet.

Negative correlation between leftward bias in line bisection and schizotypal features in healthy subjects

PubMed Central

Ribolsi, Michele; Lisi, Giulia; Di Lorenzo, Giorgio; Rociola, Giuseppe; Niolu, Cinzia; Siracusano, Alberto

2013-01-01

Introduction: Recent studies have found a lack of normal pseudoneglect in schizophrenia patients and in their first degree relatives. Similarly, several contributions have reported that measures of schizotypy in the healthy population may be related to signs of right-sided lateralization, but most of these studies differ greatly in methodology (sample size, choice of schizotypy scales, and laterality tasks) and, consequently, the results cannot be compared and so definitive conclusion cannot be drawn. In this study, our purpose is to investigate whether some tasks of spatial attention may be related to different dimensions of schizotypy not only in a larger sample of healthy subjects (HS), but testing the same people with several supposedly related measures several times. Materials and Methods: In the first part of the study (Part I), the performance on “paper and pencil” line bisection (LB) tasks in 205 HS was investigated. Each task was repeated three times. In the second part of the study (Part II), a subgroup of 80 subjects performed a computerized version of the LB test and of the mental number line bisection (MNL) test. In both parts of the study, every subject completed the 74-item version of the Schizotypal Personality Questionnaire (SPQ) and the Edinburgh Handedness Inventory (EHI). Results: In both parts of the study, high scores on the subscale “magical thinking” of SPQ have resulted in being closely linked to a decreased pseudoneglect as assessed by the LB task. On the contrary, right handedness is related to an increased leftward bias at the same task. No association was found between MNL and the other variables. Discussion: The main finding of this study is that a decreased spatial leftward bias at the LB task correlates with positive schizotypy in the healthy population. This finding supports the hypothesis that a deviation from leftward hemispatial visual preference may be related to the degree of psychosis-like schizotypal signs in non-clinical population and should be investigated as a possible marker of psychosis. PMID:24294208

Effects of monocular viewing and eye dominance on spatial attention.

PubMed

Roth, Heidi L; Lora, Andrea N; Heilman, Kenneth M

2002-09-01

Observations in primates and patients with unilateral spatial neglect have suggested that patching of the eye ipsilateral to the injury and contralateral to the neglected space can sometimes improve attention to the neglected space. Investigators have generally attributed the effects of monocular eye patching to activation of subcortical centers that interact with cortical attentional systems. Eye patching is thought to produce preferential activation of attentional systems contralateral to the viewing eye. In this study we examined the effect of monocular eye patching on attentional biases in normal subjects. When normal subjects bisect vertical (radial) lines using both eyes, they demonstrate a far attentional bias, misbisecting lines away from their body. In a monocular viewing experiment, we found that the majority of subjects, who were right eye dominant, had relatively nearer bisections and a diminished far bias when they used their right eye (left eye covered) compared with when they used their left eye (right eye covered). The smaller group of subjects who were left eye dominant had relatively nearer bisections and a diminished far bias when they used their left eye compared with when they used their right eye. In the hemispatial placement experiment, we directly manipulated hemispheric engagement by having subjects perform the same task in right and left hemispace. We found that right eye dominant subjects had a diminished far bias in right hemispace relative to left hemispace. Left eye dominant subjects showed the opposite pattern and had a diminished far bias in left hemispace. For both groups, spatial presentation affected performance more for the non-dominant eye. The results suggest that monocular viewing is associated with preferential activation of attentional systems in the contralateral hemisphere, and that the right hemisphere (at least in right eye dominant subjects) is biased towards far space. Finally, the results suggest that the poorly understood phenomenon of eye dominance may be related to hemispheric specialization for visual attention.

Near and far space neglect: task sensitivity and anatomical substrates.

PubMed

Aimola, Lina; Schindler, Igor; Simone, Anna Maria; Venneri, Annalena

2012-05-01

Most group studies which have investigated neglect for near and far space have found an increased severity of symptoms in far space compared to near space. However, the majority of these studies used relatively small samples and based their findings almost exclusively on line bisection performance. The aim of the present study was, therefore, to explore the occurrence of neglect for near and far space in a larger group of unselected right brain damaged patients and to evaluate whether neglect specific to near and far space is a task-related deficit or generalises across distance irrespective of task. In addition, a lesion overlap analysis was carried out to identify critical lesion sites associated with distance specific neglect deficits. Thirty-eight right hemisphere damaged patients carried out a line bisection and a cancellation task by using a pen in near space (40 cm) and a laser pointer in far space (320 cm). The results showed that both the number of left-sided omissions and rightward bisection errors were significantly increased in near compared to far space. Distance specific dissociations, albeit less common, were more frequently observed for cancellation than line bisection. These results suggest that space representation in neglect is more severely impaired in near than in far space. In addition, distance related dissociations in neglect may depend on task demands. Although the anatomical findings were broadly consistent with a dorsal and ventral stream dichotomy for near and far space processing, they also suggest the involvement of intermediate structures in distance related neglect phenomena. Copyright © 2012 Elsevier Ltd. All rights reserved.

Visual neglect following stroke: current concepts and future focus.

PubMed

Ting, Darren S J; Pollock, Alex; Dutton, Gordon N; Doubal, Fergus N; Ting, Daniel S W; Thompson, Michelle; Dhillon, Baljean

2011-01-01

Visual neglect is a common, yet frequently overlooked, neurological disorder following stroke characterized by a deficit in attention and appreciation of stimuli on the contralesional side of the body. It has a profound functional impact on affected individuals. A assessment and management of this condition are hindered, however, by the lack of professional awareness and clinical guidelines. Recent evidence suggests that the underlying deficit in visual attention is due to a disrupted internalized representation of the outer world rather than a disorder of sensory inputs. Dysfunction of the cortical domains and white-matter tracts, as well as inter-hemispheric imbalance, have been implicated in the various manifestations of visual neglect. Optimal diagnosis requires careful history-taking from the patient, family, and friends, in addition to clinical assessment with the line bisection test, the star cancellation test, and the Catherine Bergego Scale. Early recognition and prompt rehabilitation employing a multidisciplinary approach is desirable. Although no treatment has been definitively shown to be of benefit, those with promise include prism adaptation, visual scanning therapy, and virtual reality-based techniques. Further high quality research to seek optimum short- and long-term rehabilitative strategies for visual neglect is required. Copyright © 2011 Elsevier Inc. All rights reserved.

Clock-drawing test and unilateral spatial neglect.

PubMed

Ishiai, S; Sugishita, M; Ichikawa, T; Gono, S; Watabiki, S

1993-01-01

We investigated the ability of 25 patients with left unilateral spatial neglect to make a clock face by putting numbers inside a printed circle. Impairment seen in this clock-drawing test did not parallel neglect severity as judged by results of the line-cancellation and line-bisection tests, as well as the copying of a daisy. The score for clock drawing correlated highly with the verbal WAIS score. Most neglect patients with a verbal IQ of 87 or more could draw a clock face fairly well and used planning in placing the numbers 12, 3, 6, and 9 before the others. In clock drawing, verbal intelligence may compensate for left unilateral spatial neglect. We therefore recommend use of the line-cancellation and line-bisection tests, as well as the copying test, but do not recommend use of the clock-drawing test in the diagnosis of left unilateral spatial neglect.

'Where' depends on 'what': a differential functional anatomy for position discrimination in one- versus two-dimensions.

PubMed

Fink, G R; Marshall, J C; Weiss, P H; Shah, N J; Toni, I; Halligan, P W; Zilles, K

2000-01-01

Line bisection is widely used as a clinical test of spatial cognition in patients with left visuospatial neglect after right hemisphere lesion. Surprisingly, many neglect patients who show severe impairment on marking the center of horizontal lines can accurately mark the center of squares. That these patients with left neglect are also typically poor at judging whether lines are correctly prebisected implies that the deficit can be perceptual rather than motoric. These findings suggest a differential neural basis for one- and two-dimensional visual position discrimination that we investigated with functional neuroimaging (fMRI). Normal subjects judged whether, in premarked lines or squares, the mark was placed centrally. Line center judgements differentially activated right parietal cortex, while square center judgements differentially activated the lingual gyrus bilaterally. These distinct neural bases for one- and two-dimensional visuospatial judgements help explain the observed clinical dissociations by showing that as a stimulus becomes a better, more 'object-like' gestalt, the ventral visuoperceptive route assumes more responsibility for assessing position within the object.

Monocular Patching May Induce Ipsilateral “Where” Spatial Bias

PubMed Central

Chen, Peii; Erdahl, Lillian; Barrett, Anna M.

2009-01-01

Spatial bias is an asymmetry of perception and/or representation of spatial information —“where” bias —, or of spatially directed actions — “aiming” bias. A monocular patch may induce contralateral “where” spatial bias (the Sprague effect; Sprague (1966) Science, 153, 1544–1547). However, an ipsilateral patch-induced spatial bias may be observed if visual occlusion results in top-down, compensatory re-allocation of spatial perceptual or representational resources toward the region of visual deprivation. Tactile distraction from a monocular patch may also contribute to an ipsilateral bias. To examine these hypotheses, neurologically normal adults bisected horizontal lines at baseline without a patch, while wearing a monocular patch, and while wearing tactile-only and visual-only monocular occlusion. We fractionated “where” and “aiming” spatial bias components using a video apparatus to reverse visual feedback for half of the test trials. The results support monocular patch-induced ipsilateral “where” spatial errors, which are not consistent with the Sprague effect. Further, the present findings suggested that the induced ipsilateral bias may be primarily induced by visual deprivation, consistent with compensatory “where” resource re-allocation. PMID:19100274

Image of a line is not shrunk but neglected. Absence of crossover in unilateral spatial neglect.

PubMed

Ishiai, Sumio; Koyama, Yasumasa; Nakano, Naomi; Seki, Keiko; Nishida, Yoichiro; Hayashi, Kazuko

2004-01-01

Patients with left unilateral spatial neglect following right hemisphere lesions usually err rightward when bisecting a horizontal line. For very short lines (e.g. 25 mm), however, leftward errors or seemingly 'right' neglect is often observed. To explain this paradox of crossover in the direction of errors, rather complicated models have been introduced as to the distribution of attention. Neglect may be hypothesized to occur in representational process of a line or estimation of the midpoint on the formed image, or both. We devised a line image task using a computer display with a touch panel and approached the representational image of a line to be bisected. Three patients with typical left neglect were presented with a line and forced to see its whole extent with cueing to the left endpoint. After disappearance of the line, they pointed to the right endpoint, the left endpoint, or the subjective midpoint according to their representational image. The line image between the reproduced right and left endpoints was appropriately formed for the 200 mm lines. However, the images for the shorter 25 and 100 mm lines were longer than the physical lengths with overextension to the left side. These results proved the context effect that short lines may be perceived longer when they are presented in combination with longer lines. One of our patients had an extensive lesion that involved the frontal, temporal, and parietal lobes, and the other two had a lesion restricted to the posterior right hemisphere. The image for a fully perceived line may be represented far enough into left space even when left neglect occurs after a lesion that involves the right parietal lobe. The patients with neglect placed the subjective midpoint rightward from the centre of the stimulus line for the 100 and 200 mm lines and leftward for the 25 mm lines. This crossover of bisection errors disappeared when the displacement of the subjective midpoint was measured from the centre of the representational line image. Left neglect may occur consistently in estimation of the subjective midpoint on the representational image, which may be explained by a simple rightward bias of attentional distribution.

Auditory and Visual Differences in Time Perception? An Investigation from a Developmental Perspective with Neuropsychological Tests

ERIC Educational Resources Information Center

Zelanti, Pierre S.; Droit-Volet, Sylvie

2012-01-01

Adults and children (5- and 8-year-olds) performed a temporal bisection task with either auditory or visual signals and either a short (0.5-1.0s) or long (4.0-8.0s) duration range. Their working memory and attentional capacities were assessed by a series of neuropsychological tests administered in both the auditory and visual modalities. Results…

The role of the right superior temporal gyrus in stimulus-centered spatial processing.

PubMed

Shah-Basak, Priyanka P; Chen, Peii; Caulfield, Kevin; Medina, Jared; Hamilton, Roy H

2018-05-01

Although emerging neuropsychological evidence supports the involvement of temporal areas, and in particular the right superior temporal gyrus (STG), in allocentric neglect deficits, the role of STG in healthy spatial processing remains elusive. While several functional brain imaging studies have demonstrated involvement of the STG in tasks involving explicit stimulus-centered judgments, prior rTMS studies targeting the right STG did not find the expected neglect-like rightward bias in size judgments using the conventional landmark task. The objective of the current study was to investigate whether disruption of the right STG using inhibitory repetitive transcranial magnetic stimulation (rTMS) could impact stimulus-centered, allocentric spatial processing in healthy individuals. A lateralized version of the landmark task was developed to accentuate the dissociation between viewer-centered and stimulus-centered reference frames. We predicted that inhibiting activity in the right STG would decrease accuracy because of induced rightward bias centered on the line stimulus irrespective of its viewer-centered or egocentric locations. Eleven healthy, right-handed adults underwent the lateralized landmark task. After viewing each stimulus, participants had to judge whether the line was bisected, or whether the left (left-long trials) or the right segment (right-long trials) of the line was longer. Participants repeated the task before (pre-rTMS) and after (post-rTMS) receiving 20 min of 1 Hz rTMS over the right STG, the right supramarginal gyrus (SMG), and the vertex (a control site) during three separate visits. Linear mixed models for binomial data were generated with either accuracy or judgment errors as dependent variables, to compare 1) performance across trial types (bisection, non-bisection), and 2) pre- vs. post-rTMS performance between the vertex and the STG and the vertex and the SMG. Line eccentricity (z = 4.31, p < 0.0001) and line bisection (z = 5.49, p < 0.0001) were significant predictors of accuracy. In the models comparing the effects of rTMS, a significant two-way interaction with STG (z = -3.09, p = 0.002) revealed a decrease in accuracy of 9.5% and an increase in errors of the right-long type by 10.7% on bisection trials, in both left and right viewer-centered locations. No significant changes in leftward errors were found. These findings suggested an induced stimulus-centered rightward bias in our participants after STG stimulation. Notably, accuracy or errors were not influenced by SMG stimulation compared to vertex. In line with our predictions, the findings provide compelling evidence for right STG's involvement in healthy stimulus-centered spatial processing. Copyright © 2018 Elsevier Ltd. All rights reserved.

Left to Right: Representational Biases for Numbers and the Effect of Visuomotor Adaptation

ERIC Educational Resources Information Center

Loftus, Andrea M.; Nicholls, Michael E. R.; Mattingley, Jason B.; Bradshaw, John L.

2008-01-01

Adaptation to right-shifting prisms improves left neglect for mental number line bisection. This study examined whether adaptation affects the mental number line in normal participants. Thirty-six participants completed a mental number line task before and after adaptation to either: left-shifting prisms, right-shifting prisms or control…

The Influence of Tactile Cognitive Maps on Auditory Space Perception in Sighted Persons.

PubMed

Tonelli, Alessia; Gori, Monica; Brayda, Luca

2016-01-01

We have recently shown that vision is important to improve spatial auditory cognition. In this study, we investigate whether touch is as effective as vision to create a cognitive map of a soundscape. In particular, we tested whether the creation of a mental representation of a room, obtained through tactile exploration of a 3D model, can influence the perception of a complex auditory task in sighted people. We tested two groups of blindfolded sighted people - one experimental and one control group - in an auditory space bisection task. In the first group, the bisection task was performed three times: specifically, the participants explored with their hands the 3D tactile model of the room and were led along the perimeter of the room between the first and the second execution of the space bisection. Then, they were allowed to remove the blindfold for a few minutes and look at the room between the second and third execution of the space bisection. Instead, the control group repeated for two consecutive times the space bisection task without performing any environmental exploration in between. Considering the first execution as a baseline, we found an improvement in the precision after the tactile exploration of the 3D model. Interestingly, no additional gain was obtained when room observation followed the tactile exploration, suggesting that no additional gain was obtained by vision cues after spatial tactile cues were internalized. No improvement was found between the first and the second execution of the space bisection without environmental exploration in the control group, suggesting that the improvement was not due to task learning. Our results show that tactile information modulates the precision of an ongoing space auditory task as well as visual information. This suggests that cognitive maps elicited by touch may participate in cross-modal calibration and supra-modal representations of space that increase implicit knowledge about sound propagation.

Making Time for Nature: Visual Exposure to Natural Environments Lengthens Subjective Time Perception and Reduces Impulsivity

PubMed Central

Berry, Meredith S.; Repke, Meredith A.; Nickerson, Norma P.; Conway, Lucian G.; Odum, Amy L.; Jordan, Kerry E.

2015-01-01

Impulsivity in delay discounting is associated with maladaptive behaviors such as overeating and drug and alcohol abuse. Researchers have recently noted that delay discounting, even when measured by a brief laboratory task, may be the best predictor of human health related behaviors (e.g., exercise) currently available. Identifying techniques to decrease impulsivity in delay discounting, therefore, could help improve decision-making on a global scale. Visual exposure to natural environments is one recent approach shown to decrease impulsive decision-making in a delay discounting task, although the mechanism driving this result is currently unknown. The present experiment was thus designed to evaluate not only whether visual exposure to natural (mountains, lakes) relative to built (buildings, cities) environments resulted in less impulsivity, but also whether this exposure influenced time perception. Participants were randomly assigned to either a natural environment condition or a built environment condition. Participants viewed photographs of either natural scenes or built scenes before and during a delay discounting task in which they made choices about receiving immediate or delayed hypothetical monetary outcomes. Participants also completed an interval bisection task in which natural or built stimuli were judged as relatively longer or shorter presentation durations. Following the delay discounting and interval bisection tasks, additional measures of time perception were administered, including how many minutes participants thought had passed during the session and a scale measurement of whether time "flew" or "dragged" during the session. Participants exposed to natural as opposed to built scenes were less impulsive and also reported longer subjective session times, although no differences across groups were revealed with the interval bisection task. These results are the first to suggest that decreased impulsivity from exposure to natural as opposed to built environments may be related to lengthened time perception. PMID:26558610

The Effect of Hemispatial Neglect on the Perception of Centre

ERIC Educational Resources Information Center

Olk, Bettina; Wee, Joy; Kingstone, Alan

2004-01-01

Highly variable bisection performance in neglect patients has been attributed to an increased "zone of indifference" (Marshall & Halligan, 1989). The indifference zone indicates the discrepancy between two line lengths which are judged as equal in length. Following this argumentation, the central area of a line should be expanded in neglect…

A neuroanatomical model of space-based and object-centered processing in spatial neglect.

PubMed

Pedrazzini, Elena; Schnider, Armin; Ptak, Radek

2017-11-01

Visual attention can be deployed in space-based or object-centered reference frames. Right-hemisphere damage may lead to distinct deficits of space- or object-based processing, and such dissociations are thought to underlie the heterogeneous nature of spatial neglect. Previous studies have suggested that object-centered processing deficits (such as in copying, reading or line bisection) result from damage to retro-rolandic regions while impaired spatial exploration reflects damage to more anterior regions. However, this evidence is based on small samples and heterogeneous tasks. Here, we tested a theoretical model of neglect that takes in account the space- and object-based processing and relates them to neuroanatomical predictors. One hundred and one right-hemisphere-damaged patients were examined with classic neuropsychological tests and structural brain imaging. Relations between neglect measures and damage to the temporal-parietal junction, intraparietal cortex, insula and middle frontal gyrus were examined with two structural equation models by assuming that object-centered processing (involved in line bisection and single-word reading) and space-based processing (involved in cancelation tasks) either represented a unique latent variable or two distinct variables. Of these two models the latter had better explanatory power. Damage to the intraparietal sulcus was a significant predictor of object-centered, but not space-based processing, while damage to the temporal-parietal junction predicted space-based, but not object-centered processing. Space-based processing and object-centered processing were strongly intercorrelated, indicating that they rely on similar, albeit partly dissociated processes. These findings indicate that object-centered and space-based deficits in neglect are partly independent and result from superior parietal and inferior parietal damage, respectively.

Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation.

PubMed

Christophe, Laure; Chabanat, Eric; Delporte, Ludovic; Revol, Patrice; Volckmann, Pierre; Jacquin-Courtois, Sophie; Rossetti, Yves

Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations.

Feeling socially powerless makes you more prone to bumping into things on the right and induces leftward line bisection error.

PubMed

Wilkinson, David; Guinote, Ana; Weick, Mario; Molinari, Rosanna; Graham, Kylee

2010-12-01

Social power affects the manner in which people view themselves and act toward others, a finding that has attracted broad interest from the social and political sciences. However, there has been little interest from those within cognitive neuroscience. Here, we demonstrate that the effects of power extend beyond social interaction and invoke elementary spatial biases in behavior consistent with preferential hemispheric activation. In particular, participants who felt relatively powerless, compared with those who felt more powerful, were more likely to bisect horizontal lines to the left of center, and bump into the right-hand (as opposed to the left-hand) side when walking through a narrow passage. These results suggest that power induces hemispheric differences in visuomotor behavior, indicating that this ubiquitous phenomenon affects not only how we interact with one another, but also how we interact with the physical world.

The amusic brain: lost in music, but not in space.

PubMed

Tillmann, Barbara; Jolicoeur, Pierre; Ishihara, Masami; Gosselin, Nathalie; Bertrand, Olivier; Rossetti, Yves; Peretz, Isabelle

2010-04-21

Congenital amusia is a neurogenetic disorder of music processing that is currently ascribed to a deficit in pitch processing. A recent study challenges this view and claims the disorder might arise as a consequence of a general spatial-processing deficit. Here, we assessed spatial processing abilities in two independent samples of individuals with congenital amusia by using line bisection tasks (Experiment 1) and a mental rotation task (Experiment 2). Both amusics and controls showed the classical spatial effects on bisection performance and on mental rotation performance, and amusics and controls did not differ from each other. These results indicate that the neurocognitive impairment of congenital amusia does not affect the processing of space.

Cerebral Asymmetry of fMRI-BOLD Responses to Visual Stimulation

PubMed Central

Hougaard, Anders; Jensen, Bettina Hagström; Amin, Faisal Mohammad; Rostrup, Egill; Hoffmann, Michael B.; Ashina, Messoud

2015-01-01

Hemispheric asymmetry of a wide range of functions is a hallmark of the human brain. The visual system has traditionally been thought of as symmetrically distributed in the brain, but a growing body of evidence has challenged this view. Some highly specific visual tasks have been shown to depend on hemispheric specialization. However, the possible lateralization of cerebral responses to a simple checkerboard visual stimulation has not been a focus of previous studies. To investigate this, we performed two sessions of blood-oxygenation level dependent (BOLD) functional magnetic resonance imaging (fMRI) in 54 healthy subjects during stimulation with a black and white checkerboard visual stimulus. While carefully excluding possible non-physiological causes of left-to-right bias, we compared the activation of the left and the right cerebral hemispheres and related this to grey matter volume, handedness, age, gender, ocular dominance, interocular difference in visual acuity, as well as line-bisection performance. We found a general lateralization of cerebral activation towards the right hemisphere of early visual cortical areas and areas of higher-level visual processing, involved in visuospatial attention, especially in top-down (i.e., goal-oriented) attentional processing. This right hemisphere lateralization was partly, but not completely, explained by an increased grey matter volume in the right hemisphere of the early visual areas. Difference in activation of the superior parietal lobule was correlated with subject age, suggesting a shift towards the left hemisphere with increasing age. Our findings suggest a right-hemispheric dominance of these areas, which could lend support to the generally observed leftward visual attentional bias and to the left hemifield advantage for some visual perception tasks. PMID:25985078

Multi-jagged: A scalable parallel spatial partitioning algorithm

DOE PAGES

Deveci, Mehmet; Rajamanickam, Sivasankaran; Devine, Karen D.; ...

2015-03-18

Geometric partitioning is fast and effective for load-balancing dynamic applications, particularly those requiring geometric locality of data (particle methods, crash simulations). We present, to our knowledge, the first parallel implementation of a multidimensional-jagged geometric partitioner. In contrast to the traditional recursive coordinate bisection algorithm (RCB), which recursively bisects subdomains perpendicular to their longest dimension until the desired number of parts is obtained, our algorithm does recursive multi-section with a given number of parts in each dimension. By computing multiple cut lines concurrently and intelligently deciding when to migrate data while computing the partition, we minimize data movement compared to efficientmore » implementations of recursive bisection. We demonstrate the algorithm's scalability and quality relative to the RCB implementation in Zoltan on both real and synthetic datasets. Our experiments show that the proposed algorithm performs and scales better than RCB in terms of run-time without degrading the load balance. Lastly, our implementation partitions 24 billion points into 65,536 parts within a few seconds and exhibits near perfect weak scaling up to 6K cores.« less

Spatial and numerical processing in children with high and low visuospatial abilities.

PubMed

Crollen, Virginie; Noël, Marie-Pascale

2015-04-01

In the literature on numerical cognition, a strong association between numbers and space has been repeatedly demonstrated. However, only a few recent studies have been devoted to examine the consequences of low visuospatial abilities on calculation processing. In this study, we wanted to investigate whether visuospatial weakness may affect pure spatial processing as well as basic numerical reasoning. To do so, the performances of children with high and low visuospatial abilities were directly compared on different spatial tasks (the line bisection and Simon tasks) and numerical tasks (the number bisection, number-to-position, and numerical comparison tasks). Children from the low visuospatial group presented the classic Simon and SNARC (spatial numerical association of response codes) effects but showed larger deviation errors as compared with the high visuospatial group. Our results, therefore, demonstrated that low visuospatial abilities did not change the nature of the mental number line but rather led to a decrease in its accuracy. Copyright © 2014 Elsevier Inc. All rights reserved.

Prisms to Shift Pain Away: Pathophysiological and Therapeutic Exploration of CRPS with Prism Adaptation

PubMed Central

Volckmann, Pierre; Jacquin-Courtois, Sophie

2016-01-01

Complex Regional Pain Syndrome (CRPS) is an invalidating chronic condition subsequent to peripheral lesions. There is growing consensus for a central contribution to CRPS. However, the nature of this central body representation disorder is increasingly debated. Although it has been repeatedly argued that CRPS results in motor neglect of the affected side, visual egocentric reference frame was found to be deviated toward the pain, that is, neglect of the healthy side. Accordingly, prism adaptation has been successfully used to normalize this deviation. This study aimed at clarifying whether 7 CRPS patients exhibited neglect as well as exploring the pathophysiological mechanisms of this manifestation and of the therapeutic effects of prism adaptation. Pain and quality of life, egocentric reference frames (visual and proprioceptive straight-ahead), and neglect tests (line bisection, kinematic analyses of motor neglect and motor extinction) were repeatedly assessed prior to, during, and following a one-week intense prism adaptation intervention. First, our results provide no support for visual and motor neglect in CRPS. Second, reference frames for body representations were not systematically deviated. Third, intensive prism adaptation intervention durably ameliorated pain and quality of life. As for spatial neglect, understanding the therapeutic effects of prism adaptation deserves further investigations. PMID:27668094

Rightward Biases in Free-Viewing Visual Bisection Tasks: Implications for Leftward Responses Biases on Similar Tasks

ERIC Educational Resources Information Center

Elias, Lorin J.; Robinson, Brent; Saucier, Deborah M.

2005-01-01

Neurologically normal individuals exhibit strong leftward response biases during free-viewing perceptual judgments of brightness, quantity, and size. When participants view two mirror-reversed objects and they are forced to choose which object appears darker, more numerous, or larger, the stimulus with the relevant feature on the left side is…

Near Space and Its Relation to Claustrophobic Fear

ERIC Educational Resources Information Center

Lourenco, Stella F.; Longo, Matthew R.; Pathman, Thanujeni

2011-01-01

It is well established that the near space immediately surrounding the body (also known as peripersonal space) is represented differently than the space farther away. When bisecting horizontal lines, for example, neurologically-healthy adults show a slight leftward bias (known as pseudoneglect) in near space; this attentional bias, however,…

Simulating hemispatial neglect with virtual reality.

PubMed

Baheux, Kenji; Yoshizawa, Makoto; Yoshida, Yasuko

2007-07-19

Hemispatial neglect is a cognitive disorder defined as a lack of attention for stimuli contra-lateral to the brain lesion. The assessment is traditionally done with basic pencil and paper tests and the rehabilitation programs are generally not well adapted. We propose a virtual reality system featuring an eye-tracking device for a better characterization of the neglect that will lead to new rehabilitation techniques. This paper presents a comparison of eye-gaze patterns of healthy subjects, patients and healthy simulated patients on a virtual line bisection test. The task was also executed with a reduced visual field condition hoping that fewer stimuli would limit the neglect. We found that patients and healthy simulated patients had similar eye-gaze patterns. However, while the reduced visual field condition had no effect on the healthy simulated patients, it actually had a negative impact on the patients. We discuss the reasons for these differences and how they relate to the limitations of the neglect simulation. We argue that with some improvements the technique could be used to determine the potential of new rehabilitation techniques and also help the rehabilitation staff or the patient's relatives to better understand the neglect condition.

Bisecting Microfluidic Channels with Metallic Nanowires Fabricated by Nanoskiving.

PubMed

Kalkman, Gerard A; Zhang, Yanxi; Monachino, Enrico; Mathwig, Klaus; Kamminga, Machteld E; Pourhossein, Parisa; Oomen, Pieter E; Stratmann, Sarah A; Zhao, Zhiyuan; van Oijen, Antoine M; Verpoorte, Elisabeth; Chiechi, Ryan C

2016-02-23

This paper describes the fabrication of millimeter-long gold nanowires that bisect the center of microfluidic channels. We fabricated the nanowires by nanoskiving and then suspended them over a trench in a glass structure. The channel was sealed by bonding it to a complementary poly(dimethylsiloxane) structure. The resulting structures place the nanowires in the region of highest flow, as opposed to the walls, where it approaches zero, and expose their entire surface area to fluid. We demonstrate active functionality, by constructing a hot-wire anemometer to measure flow through determining the change in resistance of the nanowire as a function of heat dissipation at low voltage (<5 V). Further, passive functionality is demonstrated by visualizing individual, fluorescently labeled DNA molecules attached to the wires. We measure rates of flow and show that, compared to surface-bound DNA strands, elongation saturates at lower rates of flow and background fluorescence from nonspecific binding is reduced.

Paradoxical Cross-Over Due to Attention to High or Low Spatial Frequencies

ERIC Educational Resources Information Center

Niemeier, Matthias; Stojanoski, Boge; Singh, Vaughan W. A.; Chu, Eddie

2008-01-01

The mechanisms underlying the right hemisphere's dominance for spatial and attentional functions lacks a comprehensively explanation. For example, perceptual biases, as observed in line bisection and related tasks, might be caused by an attentional asymmetry or by perceptual processes such as a specialization of the left and right hemisphere for…

Reduced Pseudoneglect for Physical Space, but Not Mental Representations of Space, for Adults with Autistic Traits

ERIC Educational Resources Information Center

English, Michael C.; Maybery, Murray T.; Visser, Troy A.

2017-01-01

Neurotypical individuals display a leftward attentional bias, called pseudoneglect, for physical space (e.g. landmark task) and mental representations of space (e.g. mental number line bisection). However, leftward bias is reduced in autistic individuals viewing faces, and neurotypical individuals with autistic traits viewing "greyscale"…

Developmental Trajectory of Pseudoneglect in Adults Using the Greyscales Task

ERIC Educational Resources Information Center

Friedrich, Trista E.; Hunter, Paulette V.; Elias, Lorin J.

2016-01-01

Neurologically healthy adults display a reliable but slight leftward spatial bias, and this bias appears to change with age (Jewell & McCourt, 2000). Studies using line bisection and the landmark task to investigate pseudoneglect in participants over 60 years of age have shown suppression and near reversal of the leftward response bias. The…

Exaggerated Leftward Bias in the Mental Number Line of Patients with Schizophrenia

ERIC Educational Resources Information Center

Cavezian, Celine; Rossetti, Yves; Danckert, James; d'Amato, Thierry; Dalery, Jean; Saoud, Mohamed

2007-01-01

Several visuo-motor tasks can be used to demonstrate biases towards left hemispace in schizophrenic patients, suggesting a minor right hemineglect. Recent studies in neglect patients used a new number bisection task to highlight a lateralized defect in their visuo-spatial representation of numbers. To test a possible lateralized representational…

Development of Visuospatial Attention in Typically Developing Children

PubMed Central

Ickx, Gaétan; Bleyenheuft, Yannick; Hatem, Samar M.

2017-01-01

The aim of the present study is to investigate the development of visuospatial attention in typically developing children and to propose reference values for children for the following six visuospatial attention tests: star cancellation, Ogden figure, reading test, line bisection, proprioceptive pointing and visuo-proprioceptive pointing. Data of 159 children attending primary or secondary school in the Fédération Wallonie Bruxelles (Belgium) were analyzed. Results showed that the children's performance on star cancellation, Ogden figure and reading test improved until the age of 13 years, whereas their performance on proprioceptive pointing, visuo-proprioceptive pointing and line bisection was stable with increasing age. These results suggest that the execution of different types of visuospatial attention tasks are not following the same developmental trajectories. This dissociation is strengthened by the lack of correlation observed between tests assessing egocentric and allocentric visuospatial attention, except for the star cancellation test (egocentric) and the Ogden figure copy (ego- and allocentric). Reference values are proposed that may be useful to examine children with clinical disorders of visuospatial attention. PMID:29270138

Prism adaptation in the healthy brain: the shift in line bisection judgments is long lasting and fluctuates.

PubMed

Schintu, Selene; Pisella, Laure; Jacobs, Stéphane; Salemme, Romeo; Reilly, Karen T; Farnè, Alessandro

2014-01-01

Rightward prism adaptation has been shown to ameliorate visuospatial biases in right brain-damaged patients with neglect, and a single session of prism adaptation can lead to improvements that last up to several hours. Leftward prism adaptation in neurologically healthy individuals induces neglect-like biases in visuospatial tasks. The duration of these effects in healthy individuals, typically assumed to be ephemeral, has never been investigated. Here we assessed the time-course of the adaptation-induced modifications in a classical perceptual line bisection task that was repeatedly administered for approximately 40min after a single session of adaptation to either a leftward or rightward prismatic deviation. Consistent with previous reports, only adaptation to leftward-deviating prisms induced a visuospatial shift on perceptual line bisection judgments. The typical pattern of pseudoneglect was counteracted by a rightward shift in midline judgments, which became significant between 5 and 10 min after adaptation, fluctuated between being significant or not several times in the 40 min following adaptation, and was present as late as 35 min. In contrast, the sensorimotor aftereffect was present immediately after adaptation to both rightward and leftward deviating prisms, decayed initially then remained stable until 40 min. These results demonstrate that both the sensorimotor and visuospatial effects last for at least 35 min, but that the visuospatial shift needs time to fully develop and fluctuates. By showing that the effects of prism adaptation in the undamaged brain are not ephemeral, these findings reveal the presence of another, so-far neglected dimension in the domain of the cognitive effects induced by prism adaptation, namely time. The prolonged duration of the induced visuospatial shift, previously considered to be a feature of prism adaptation unique to brain-damaged subjects, also applies to the normal brain. © 2013 Published by Elsevier Ltd.

Pseudoneglect in line bisection judgement is associated with a modulation of right hemispheric spatial attention dominance in right-handers.

PubMed

Zago, Laure; Petit, Laurent; Jobard, Gael; Hay, Julien; Mazoyer, Bernard; Tzourio-Mazoyer, Nathalie; Karnath, Hans-Otto; Mellet, Emmanuel

2017-01-08

The objective of this study was to validate a line bisection judgement (LBJ) task for use in investigating the lateralized cerebral bases of spatial attention in a sample of 51 right-handed healthy participants. Using functional magnetic resonance imaging (fMRI), the participants performed a LBJ task that was compared to a visuomotor control task during which the participants made similar saccadic and motoric responses. Cerebral lateralization was determined using a voxel-based functional asymmetry analysis and a hemispheric functional lateralization index (HFLI) computed from fMRI contrast images. Behavioural attentional deviation biases were assessed during the LBJ task and a "paper and pencil" symbol cancellation task (SCT). Individual visuospatial skills were also evaluated. The results showed that both the LBJ and SCT tasks elicited leftward spatial biases in healthy subjects, although the biases were not correlated, which indicated their independence. Neuroimaging results showed that the LBJ task elicited a right hemispheric lateralization, with rightward asymmetries found in a large posterior occipito-parietal area, the posterior calcarine sulcus (V1p) and the temporo-occipital junction (TOJ) and in the inferior frontal gyrus, the anterior insula and the superior medial frontal gyrus. The comparison of the LBJ asymmetry map to the lesion map of neglect patients who suffer line bisection deviation demonstrated maximum overlap in a network that included the middle occipital gyrus (MOG), the TOJ, the anterior insula and the inferior frontal region, likely subtending spatial LBJ bias. Finally, the LBJ task-related cerebral lateralization was specifically correlated with the LBJ spatial bias but not with the SCT bias or with the visuospatial skills of the participants. Taken together, these results demonstrated that the LBJ task is adequate for investigating spatial lateralization in healthy subjects and is suitable for determining the factors underlying the variability of spatial cerebral lateralization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Neural correlates of visuospatial bias in patients with left hemisphere stroke: a causal functional contribution analysis based on game theory.

PubMed

Malherbe, C; Umarova, R M; Zavaglia, M; Kaller, C P; Beume, L; Thomalla, G; Weiller, C; Hilgetag, C C

2017-10-12

Stroke patients frequently display spatial neglect, an inability to report, or respond to, relevant stimuli in the contralesional space. Although this syndrome is widely considered to result from the dysfunction of a large-scale attention network, the individual contributions of damaged grey and white matter regions to neglect are still being disputed. Moreover, while the neuroanatomy of neglect in right hemispheric lesions is well studied, the contributions of left hemispheric brain regions to visuospatial processing are less well understood. To address this question, 128 left hemisphere acute stroke patients were investigated with respect to left- and rightward spatial biases measured as severity of deviation in the line bisection test and as Center of Cancellation (CoC) in the Bells Test. Causal functional contributions and interactions of nine predefined grey and white matter regions of interest in visuospatial processing were assessed using Multi-perturbation Shapley value Analysis (MSA). MSA, an inference approach based on game theory, constitutes a robust and exact multivariate mathematical method for inferring functional contributions from multi-lesion patterns. According to the analysis of performance in the Bells test, leftward attentional bias (contralesional deficit) was associated with contributions of the left superior temporal gyrus and rightward attentional bias with contributions of the left inferior parietal lobe, whereas the arcuate fascicle was contributed to both contra- and ipsilesional bias. Leftward and rightward deviations in the line bisection test were related to contributions of the superior longitudinal fascicle and the inferior parietal lobe, correspondingly. Thus, Bells test and line bisection tests, as well as ipsi- and contralesional attentional biases in these tests, have distinct neural correlates. Our findings demonstrate the contribution of different grey and white matter structures to contra- and ipsilesional spatial biases as revealed by left hemisphere stroke. The results provide new insights into the role of the left hemisphere in visuospatial processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual extinction in relation to visuospatial neglect after right-hemispheric stroke: quantitative assessment and statistical lesion-symptom mapping.

PubMed

Vossel, S; Eschenbeck, P; Weiss, P H; Weidner, R; Saliger, J; Karbe, H; Fink, G R

2011-08-01

Visual neglect and extinction are two common neurological syndromes in patients with right-hemispheric brain damage. Whether and how these two syndromes are associated or share common neural substrates is still a matter of debate. To address these issues, the authors investigated 56 patients with right-hemispheric stroke with a novel diagnostic test to detect extinction and neglect. In this computerised task, subjects had to respond to target stimuli in uni- and bilateral stimulation conditions with detection probabilities being assessed. A cluster-analytical approach identified 18 patients with neglect and 13 patients with extinction. Statistical lesion-symptom mapping analyses with measures for extinction and neglect were performed. Extinction and neglect co-occurred in a subset of patients but were also observed independently from each other, thereby constituting a double dissociation. Lesions within the right inferior parietal cortex were significantly associated with the severity of visual extinction. Visuospatial neglect was related to damage of fronto-parietal brain regions, with parieto-occipital areas affecting line bisection and dorsal fronto-parietal areas affecting cancellation task performance, respectively. Quantifying lesion-induced symptoms with this novel paradigm shows that extinction and neglect are dissociable syndromes in patients with right-hemispheric stroke. Furthermore, extinction and neglect can be related to differential neural substrates, with extinction being related to focal brain damage within the right inferior parietal cortex.

A matter of hand: Causal links between hand dominance, structural organization of fronto-parietal attention networks, and variability in behavioural responses to transcranial magnetic stimulation.

PubMed

Cazzoli, Dario; Chechlacz, Magdalena

2017-01-01

Considerable evidence suggests that, on a group level, human visuospatial attention is asymmetrically organized, with a right-hemispheric dominance. The asymmetrical organization of the superior longitudinal fasciculus (SLF) has been shown to account for the right-hemispheric dominance in visual attention. However, such account is by no means universal, and large individual differences in asymmetrical performance on visuospatial tasks have been reported. Furthermore, the variability in the SLF lateralization has been shown to correlate with behavioural asymmetries. Continuous theta burst stimulation (cTBS) enables to temporarily interfere with cortical activity. cTBS applied over the posterior parietal cortex (PPC) has been previously used to systematically study attentional asymmetries. Interestingly, large individual differences in the effectiveness of stimulation have been reported. In accordance with earlier both animal and human studies, one possible cause underlying these striking individual differences might lie in the structural organization of frontoparietal pathways subserving visuospatial attention. Thus, the current study employed diffusion tractography to examine the relationship between the variability in the structural organization of the SLF and the individual differences in attentional shifts induced by a modified cTBS (cTBS mod ; triplets of pulses at 30 Hz, repeated at 6 Hz) applied over the IPS, as measured by a line bisection task. Consistent with previous studies, on a group level, cTBS mod applied over the right intraparietal sulcus (IPS) triggered a rightward bisection bias shift, and there were no significant effects of cTBS mod applied over the left IPS. However, further analyses demonstrated that both handedness and structural variability (as assessed based on hindrance modulated orientational anisotropy) within the middle and the ventral branches of the SLF predicted individual differences in the cTBS mod -induced attentional shifts. Our study thus suggests that the effects of cTBS mod over the IPS may depend on intra-hemispheric interactions between cortical loci controlling visual attention. To conclude, our findings provide converging evidence for the notion put forward previously that inter-individual variability in the structural organization of intra-hemispheric frontoparietal connections has important implications for the functional models of human visual attention. Moreover, we hypothesize that this may also be relevant for the understanding of attentional disorders and their rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bisecting GlcNAc restricts conformations of branches in model N-glycans with GlcNAc termini.

PubMed

Hanashima, Shinya; Suga, Akitsugu; Yamaguchi, Yoshiki

2018-02-01

Bisected N-glycans play significant roles in tumor migration and Alzheimer's disease through modulating the action and localization of their carrier proteins. Such biological functions are often discussed in terms of the conformation of the attached N-glycans with or without bisecting GlcNAc. To obtain insights into the effects of bisecting GlcNAc on glycan conformation, a systematic NMR structural analysis was performed on two pairs of synthetic N-glycans, with and without bisecting GlcNAc. The analysis reveals that terminal GlcNAcs and bisecting GlcNAc cooperate to restrict the conformations of both the α1-3 and α1-6 branches of N-glycans. 1 H and 13 C chemical shift comparisons suggest that bisecting GlcNAc directly modulates local conformation. Unique NOE correlations between core-mannose and the α1-3 branch mannose as well as the 3 J C-H constant of the glycoside linkage indicate that bisecting GlcNAc restricts the conformation of the 1-3 branch. The angles of the glycosidic bonds between core-mannose and α1-6 branch mannose derived from 3 J C-H and 3 J H-H coupling constants show that terminal GlcNAcs restrict the distribution of the ψ angle to 180° and the bisecting GlcNAc increases the distribution of the ω angle +60° in the presence of terminal GlcNAcs. It is feasible that restriction of branch conformations by bisecting GlcNAc has important consequences for protein-glycan interplay and following biological events. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stimulus- and state-dependence of systematic bias in spatial attention: additive effects of stimulus-size and time-on-task.

PubMed

Benwell, Christopher S Y; Harvey, Monika; Gardner, Stephanie; Thut, Gregor

2013-03-01

Systematic biases in spatial attention are a common finding. In the general population, a systematic leftward bias is typically observed (pseudoneglect), possibly as a consequence of right hemisphere dominance for visuospatial attention. However, this leftward bias can cross-over to a systematic rightward bias with changes in stimulus and state factors (such as line length and arousal). The processes governing these changes are still unknown. Here we tested models of spatial attention as to their ability to account for these effects. To this end, we experimentally manipulated both stimulus and state factors, while healthy participants performed a computerized version of a landmark task. State was manipulated by time-on-task (>1 h) leading to increased fatigue and a reliable left- to rightward shift in spatial bias. Stimulus was manipulated by presenting either long or short lines which was associated with a shift of subjective midpoint from a reliable leftward bias for long to a more rightward bias for short lines. Importantly, we found time-on-task and line length effects to be additive suggesting a common denominator for line bisection across all conditions, which is in disagreement with models that assume that bisection decisions in long and short lines are governed by distinct processes (Magnitude estimation vs Global/local distinction). Our findings emphasize the dynamic rather than static nature of spatial biases in midline judgement. They are best captured by theories of spatial attention positing that spatial bias is flexibly modulated, and subject to inter-hemispheric balance which can change over time or conditions to accommodate task demands or reflect fatigue. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sinistrals' Upper Hand: Evidence for Handedness Differences in the Representation of Body Space

ERIC Educational Resources Information Center

Hach, Sylvia; Schutz-Bosbach, Simone

2010-01-01

A difference in the perception of extrapersonal space has been shown to exist between dextrals and sinistrals. On the classical line bisection task, this difference is evident in a greater left bias for dextrals compared to sinistrals. Different modalities and regions of space can be affected. However, it has not yet been investigated whether a…

An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation.

PubMed

Seraglia, Bruno; Gamberini, Luciano; Priftis, Konstantinos; Scatturin, Pietro; Martinelli, Massimiliano; Cutini, Simone

2011-01-01

For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed.

Treatment of visual neglect in elderly patients with stroke: a single-subject series using either a scanning and cueing strategy or a left-limb activation strategy.

PubMed

Bailey, Maggie J; Riddoch, M Jane; Crome, Peter

2002-08-01

The presence of unilateral visual neglect (UVN) may adversely affect functional recovery, and rehabilitation strategies that are practical for use in clinical settings are needed. The purpose of this study was to evaluate the use of 2 approaches to reduce UVN in people who have had strokes. Seven elderly patients with stroke and severe left UVN, aged 60 to 85 years, were recruited from a stroke rehabilitation unit. A nonconcurrent, multiple-baselines-across-subjects approach, with an A-B-A treatment-withdrawal single-subject experimental design, was used. Five subjects received a scanning and cueing approach, and 2 subjects received a contralesional limb activation approach, for 10 one-hour sessions. In the former approach, active scanning to the left was encouraged by the therapist, using visual and verbal cues and a mental imagery technique, during reading and copying tasks and simple board games. In the latter approach, functional and goal-oriented left upper-limb activities in neglected hemispace were encouraged. Unilateral visual neglect was examined by a masked (blinded) examiner throughout all phases using the Star Cancellation Test, the Line Bisection Test, and the Baking Tray Task. Data were analyzed using visual and inferential statistical techniques. Both subjects who received limb activation and 3 of the 5 subjects who received scanning and cueing showed a reduction in UVN in one or more tests. This improvement was maintained during the withdrawal phase. Both approaches had a positive effect of reducing aspects of UVN in some subjects relative to no-treatment baselines. However, causality cannot be assured in the absence of controls. The approaches are practical for use in rehabilitation settings. These procedures warrant further replication across subjects, settings, and therapists.

The effects of the dopamine agonist rotigotine on hemispatial neglect following stroke.

PubMed

Gorgoraptis, Nikos; Mah, Yee-Haur; Machner, Bjoern; Singh-Curry, Victoria; Malhotra, Paresh; Hadji-Michael, Maria; Cohen, David; Simister, Robert; Nair, Ajoy; Kulinskaya, Elena; Ward, Nick; Greenwood, Richard; Husain, Masud

2012-08-01

Hemispatial neglect following right-hemisphere stroke is a common and disabling disorder, for which there is currently no effective pharmacological treatment. Dopamine agonists have been shown to play a role in selective attention and working memory, two core cognitive components of neglect. Here, we investigated whether the dopamine agonist rotigotine would have a beneficial effect on hemispatial neglect in stroke patients. A double-blind, randomized, placebo-controlled ABA design was used, in which each patient was assessed for 20 testing sessions, in three phases: pretreatment (Phase A1), on transdermal rotigotine for 7-11 days (Phase B) and post-treatment (Phase A2), with the exact duration of each phase randomized within limits. Outcome measures included performance on cancellation (visual search), line bisection, visual working memory, selective attention and sustained attention tasks, as well as measures of motor control. Sixteen right-hemisphere stroke patients were recruited, all of whom completed the trial. Performance on the Mesulam shape cancellation task improved significantly while on rotigotine, with the number of targets found on the left side increasing by 12.8% (P = 0.012) on treatment and spatial bias reducing by 8.1% (P = 0.016). This improvement in visual search was associated with an enhancement in selective attention but not on our measures of working memory or sustained attention. The positive effect of rotigotine on visual search was not associated with the degree of preservation of prefrontal cortex and occurred even in patients with significant prefrontal involvement. Rotigotine was not associated with any significant improvement in motor performance. This proof-of-concept study suggests a beneficial role of dopaminergic modulation on visual search and selective attention in patients with hemispatial neglect following stroke.

The effects of the dopamine agonist rotigotine on hemispatial neglect following stroke

PubMed Central

Gorgoraptis, Nikos; Mah, Yee-Haur; Machner, Bjoern; Singh-Curry, Victoria; Malhotra, Paresh; Hadji-Michael, Maria; Cohen, David; Simister, Robert; Nair, Ajoy; Kulinskaya, Elena; Ward, Nick; Greenwood, Richard

2012-01-01

Hemispatial neglect following right-hemisphere stroke is a common and disabling disorder, for which there is currently no effective pharmacological treatment. Dopamine agonists have been shown to play a role in selective attention and working memory, two core cognitive components of neglect. Here, we investigated whether the dopamine agonist rotigotine would have a beneficial effect on hemispatial neglect in stroke patients. A double-blind, randomized, placebo-controlled ABA design was used, in which each patient was assessed for 20 testing sessions, in three phases: pretreatment (Phase A1), on transdermal rotigotine for 7–11 days (Phase B) and post-treatment (Phase A2), with the exact duration of each phase randomized within limits. Outcome measures included performance on cancellation (visual search), line bisection, visual working memory, selective attention and sustained attention tasks, as well as measures of motor control. Sixteen right-hemisphere stroke patients were recruited, all of whom completed the trial. Performance on the Mesulam shape cancellation task improved significantly while on rotigotine, with the number of targets found on the left side increasing by 12.8% (P = 0.012) on treatment and spatial bias reducing by 8.1% (P = 0.016). This improvement in visual search was associated with an enhancement in selective attention but not on our measures of working memory or sustained attention. The positive effect of rotigotine on visual search was not associated with the degree of preservation of prefrontal cortex and occurred even in patients with significant prefrontal involvement. Rotigotine was not associated with any significant improvement in motor performance. This proof-of-concept study suggests a beneficial role of dopaminergic modulation on visual search and selective attention in patients with hemispatial neglect following stroke. PMID:22761293

Stronger cortisol response to acute psychosocial stress is correlated with larger decrease in temporal sensitivity

PubMed Central

Yao, Zhuxi; Jiang, Caihong; Zhang, Kan; Wu, Jianhui

2016-01-01

As a fundamental dimension of cognition and behavior, time perception has been found to be sensitive to stress. However, how one’s time perception changes with responses to stress is still unclear. The present study aimed to investigate the relationship between stress-induced cortisol response and time perception. A group of 40 healthy young male adults performed a temporal bisection task before and after the Trier Social Stress Test for a stress condition. A control group of 27 male participants completed the same time perception task without stress induction. In the temporal bisection task, participants were first presented with short (400 ms) and long (1,600 ms) visual signals serving as anchor durations and then required to judge whether the intermediate probe durations were more similar to the short or the long anchor. The bisection point and Weber ratio were calculated and indicated the subjective duration and the temporal sensitivity, respectively. Data showed that participants in the stress group had significantly increased salivary cortisol levels, heart rates, and negative affects compared with those in the control group. The results did not show significant group differences for the subjective duration or the temporal sensitivity. However, the results showed a significant positive correlation between stress-induced cortisol responses and decreases in temporal sensitivity indexed by increases in the Weber ratio. This correlation was not observed for the control group. Changes in subjective duration indexed by temporal bisection points were not correlated with cortisol reactivity in both the groups. In conclusion, the present study found that although no significant change was observed in time perception after an acute stressor on the group-level comparison (i.e., stress vs. nonstress group), individuals with stronger cortisol responses to stress showed a larger decrease in temporal sensitivity. This finding may provide insight into the understanding of the relationship between stress and temporal sensitivity. PMID:27257544

Epigenetic activation of MGAT3 and corresponding bisecting GlcNAc shortens the survival of cancer patients.

PubMed

Kohler, Reto S; Anugraham, Merrina; López, Mónica Núñez; Xiao, Christina; Schoetzau, Andreas; Hettich, Timm; Schlotterbeck, Goetz; Fedier, André; Jacob, Francis; Heinzelmann-Schwarz, Viola

2016-08-09

Bisecting GlcNAc on N-glycoproteins is described in E-cadherin-, EGF-, Wnt- and integrin- cancer-associated signaling pathways. However, the mechanisms regulating bisecting GlcNAc expression are not clear. Bisecting GlcNAc is attached to N-glycans through beta 1-4 N-acetylglucosaminyl transferase III (MGAT3), which is encoded by two exons flanked by high-density CpG islands. Despite a recently described correlation of MGAT3 and bisecting GlcNAc in ovarian cancer cells, it remains unknown whether DNA methylation is causative for the presence of bisecting GlcNAc. Here, we narrow down the regulatory genomic region and show that reconstitution of MGAT3 expression with 5-Aza coincides with reduced DNA methylation at the MGAT3 transcription start site. The presence of bisecting GlcNAc on released N-glycans was detected by mass spectrometry (LC-ESI-qTOF-MS/MS) in serous ovarian cancer cells upon DNA methyltransferase inhibition. The regulatory impact of DNA methylation on MGAT3 was further evaluated in 18 TCGA cancer types (n = 6118 samples) and the results indicate an improved overall survival in patients with reduced MGAT3 expression, thereby identifying long-term survivors of high-grade serous ovarian cancers (HGSOC). Epigenetic activation of MGAT3 was also confirmed in basal-like breast cancers sharing similar molecular and genetic features with HGSOC. These results provide novel insights into the epigenetic regulation of MGAT3/bisecting GlcNAc and demonstrate the importance of N-glycosylation in cancer progression.

Intermittent θ burst stimulation modulates resting-state functional connectivity in the attention network and promotes behavioral recovery in patients with visual spatial neglect.

PubMed

Cao, Lei; Fu, Wei; Zhang, Yanming; Huo, Su; Du, JuBao; Zhu, Lin; Song, Weiqun

2016-12-07

Functional connectivity changes in the attention network are viewed as a physiological signature of visual spatial neglect (VSN). The left dorsal lateral prefrontal cortex (LDLPFC) is known to initiate and monitor top-down attentional control and dynamically adjust behavioral performance. This study aimed to investigate whether increasing the activity of the LDLPFC through intermittent θ burst stimulation (iTBS) could modulate the resting-state functional connectivity in the attention network and facilitate recovery from VSN. Patients with right hemisphere stroke and VSN were randomly assigned to two groups matched for clinical characteristics and given a 10-day treatment. On each day, all patients underwent visual scanning training and motor function training and received iTBS over the LDLPFC either at 80% resting motor threshold (RMT) or at 40% RMT before the trainings. MRI, the line bisection test, and the star cancelation test were performed before and after treatment. Patients who received iTBS at 80% RMT showed a large-scale reduction in the resting-state functional connectivity extent, largely in the right attention network, and more significant improvement of behavioral performance compared with patients who received iTBS at 40% RMT. These results support that the LDLPFC potentially plays a key role in the modulation of attention networks in neglect. Increasing the activity of the LDPLPFC through iTBS can facilitate recovery from VSN in patients with stroke.

Leftward Bias of Visual Attention in Patients with End-Stage Renal Disease Receiving Dialysis: A Neglected Phenomenon.

PubMed

Mańkowska, Aleksandra; Heilman, Kenneth M; Williamson, John B; Biedunkiewicz, Bogdan; Dębska-Ślizień, Alicja; Harciarek, Michał

2017-12-01

Patients with end-stage renal disease (ESRD) who are receiving dialysis often have cognitive and behavioral changes, including impairments in sustained attention. Impairments in sustained attention appear to be the consequence of right hemisphere dysfunction. Right hemisphere brain networks are also important for the allocation of spatial attention. Therefore, the objective of this study was to learn whether patients with ESRD receiving dialysis might also have a spatial attentional bias. Eighteen nondemented patients with ESRD receiving dialysis but without any neurologic diseases (age range: 20 to 60 years) and 18 demographically matched healthy controls participated in this study. Participants performed a standard line bisection task using 24 horizontal lines (24 cm long and 2 mm thick) that were sequentially placed at eye level on a white board. Patients receiving dialysis had a significantly greater leftward bias than healthy controls. Patients with ESRD receiving dialysis appear to have an impaired ability to correctly allocate their spatial attention (spatial neglect). Although the reason for the patients' leftward bias needs to be elucidated, ESRD and/or dialysis may have induced right frontal-subcortical dysfunction that disinhibited the right parietal lobe, producing a left-sided attentional bias. Further studies are needed to test this hypothesis.

Competitive action video game players display rightward error bias during on-line video game play.

PubMed

Roebuck, Andrew J; Dubnyk, Aurora J B; Cochran, David; Mandryk, Regan L; Howland, John G; Harms, Victoria

2017-09-12

Research in asymmetrical visuospatial attention has identified a leftward bias in the general population across a variety of measures including visual attention and line-bisection tasks. In addition, increases in rightward collisions, or bumping, during visuospatial navigation tasks have been demonstrated in real world and virtual environments. However, little research has investigated these biases beyond the laboratory. The present study uses a semi-naturalistic approach and the online video game streaming service Twitch to examine navigational errors and assaults as skilled action video game players (n = 60) compete in Counter Strike: Global Offensive. This study showed a significant rightward bias in both fatal assaults and navigational errors. Analysis using the in-game ranking system as a measure of skill failed to show a relationship between bias and skill. These results suggest that a leftward visuospatial bias may exist in skilled players during online video game play. However, the present study was unable to account for some factors such as environmental symmetry and player handedness. In conclusion, video game streaming is a promising method for behavioural research in the future, however further study is required before one can determine whether these results are an artefact of the method applied, or representative of a genuine rightward bias.

Contribution of visuospatial attention, short-term memory and executive functions to performance in number interval bisection.

PubMed

Ranzini, Mariagrazia; Carbè, Katia; Gevers, Wim

2017-05-01

Number interval bisection consists of estimating the mid-number within a pair (1-9=>5). Healthy adults and right-brain damage patients can show biased performance in this task, underestimating and overestimating the mid-number, respectively. The role of visuospatial attention during this task, and its interplay with other cognitive abilities (e.g., working memory) is still object of debate. In this study we explored the relation between visuospatial attention and individual differences in working memory and executive functions during number interval bisection. To manipulate the deployment of visuospatial attention, healthy participants tracked a dot moving to the left or moving to the right while bisecting numerical intervals. We also collected information concerning verbal and visuospatial short-term memory span, and concerning verbal and visuospatial fluency scores. Beside replicating what is typically observed in this task (e.g., underestimation bias), a correlation was observed between verbal short-term memory and bisection bias, and an interesting relation between performance in the number interval bisection, verbal short-term memory, and visuospatial attention. Specifically, performance of those participants with low verbal span was affected by the direction of the moving dot, underestimating at a larger extent when the dot moved leftward than rightward. Finally, it was also observed that participants' verbal fluency ability contributed in the generation of biases in the numerical task. The finding of the involvement of abilities belonging to the verbal domain contributes to unveil the multi-componential nature of number interval bisection. Considering the debate on the nature of number interval bisection and its use in the clinical assessment of deficits following brain damage, this finding may be interesting also from a clinical perspective. Copyright © 2017 Elsevier Ltd. All rights reserved.

An exploratory fNIRS study with immersive virtual reality: a new method for technical implementation

PubMed Central

Seraglia, Bruno; Gamberini, Luciano; Priftis, Konstantinos; Scatturin, Pietro; Martinelli, Massimiliano; Cutini, Simone

2011-01-01

For over two decades Virtual Reality (VR) has been used as a useful tool in several fields, from medical and psychological treatments, to industrial and military applications. Only in recent years researchers have begun to study the neural correlates that subtend VR experiences. Even if the functional Magnetic Resonance Imaging (fMRI) is the most common and used technique, it suffers several limitations and problems. Here we present a methodology that involves the use of a new and growing brain imaging technique, functional Near-infrared Spectroscopy (fNIRS), while participants experience immersive VR. In order to allow a proper fNIRS probe application, a custom-made VR helmet was created. To test the adapted helmet, a virtual version of the line bisection task was used. Participants could bisect the lines in a virtual peripersonal or extrapersonal space, through the manipulation of a Nintendo Wiimote ® controller in order for the participants to move a virtual laser pointer. Although no neural correlates of the dissociation between peripersonal and extrapersonal space were found, a significant hemodynamic activity with respect to the baseline was present in the right parietal and occipital areas. Both advantages and disadvantages of the presented methodology are discussed. PMID:22207843

Visual and tactile length matching in spatial neglect.

PubMed

Bisiach, Edoardo; McIntosh, Robert D; Dijkerman, H Chris; McClements, Kevin I; Colombo, Mariarosa; Milner, A David

2004-01-01

Previous studies have shown that many patients with spatial neglect underestimate the horizontal extent of leftwardly located shapes (presented on screen or on paper) relative to rightwardly located shapes. This has been used to help explain their leftward biases in line bisection. In the present study we have tested patients with right hemisphere damage, either with or without neglect, on a comparable length matching task, but using 3-dimensional objects. The task was executed first visually without tactile contact, and second through touch without vision. In both sense modalities, we found that patients with neglect, but not those without, tended to underestimate leftward located objects relative to rightward located objects, differing significantly in this regard from healthy subjects. However these lateral biases were not as frequent or as pronounced as in previous studies using 2-D visual shapes. Despite the similar asymmetries in the two sense modalities, we found only a small correlation between them, and clear double dissociations were observed among our patients. We conclude that leftward length underestimation cannot be attributed to any one single cause. First it cannot be entirely due to impairments in the visual pathways, such as hemianopia and/or processing biases, since the disorder is also seen in the tactile modality. At the same time, however, length underestimation phenomena cannot be fully explained as a disruption of a supramodal central size processor, since they can occur in either vision or touch alone. Our data would fit best with a multiple-factor model in which some patients show leftward length underestimation for modality-specific reasons, while others do so due to a more high-level disruption of size judgements.

Right hemisphere dominance directly predicts both baseline V1 cortical excitability and the degree of top-down modulation exerted over low-level brain structures.

PubMed

Arshad, Q; Siddiqui, S; Ramachandran, S; Goga, U; Bonsu, A; Patel, M; Roberts, R E; Nigmatullina, Y; Malhotra, P; Bronstein, A M

2015-12-17

Right hemisphere dominance for visuo-spatial attention is characteristically observed in most right-handed individuals. This dominance has been attributed to both an anatomically larger right fronto-parietal network and the existence of asymmetric parietal interhemispheric connections. Previously it has been demonstrated that interhemispheric conflict, which induces left hemisphere inhibition, results in the modulation of both (i) the excitability of the early visual cortex (V1) and (ii) the brainstem-mediated vestibular-ocular reflex (VOR) via top-down control mechanisms. However to date, it remains unknown whether the degree of an individual's right hemisphere dominance for visuospatial function can influence, (i) the baseline excitability of the visual cortex and (ii) the extent to which the right hemisphere can exert top-down modulation. We directly tested this by correlating line bisection error (or pseudoneglect), taken as a measure of right hemisphere dominance, with both (i) visual cortical excitability measured using phosphene perception elicited via single-pulse occipital trans-cranial magnetic stimulation (TMS) and (ii) the degree of trans-cranial direct current stimulation (tDCS)-mediated VOR suppression, following left hemisphere inhibition. We found that those individuals with greater right hemisphere dominance had a less excitable early visual cortex at baseline and demonstrated a greater degree of vestibular nystagmus suppression following left hemisphere cathodal tDCS. To conclude, our results provide the first demonstration that individual differences in right hemisphere dominance can directly predict both the baseline excitability of low-level brain structures and the degree of top-down modulation exerted over them. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

The Behavioral Toxicology of High-Peak, Low Average Power, Pulsed Microwave Irradiation

DTIC Science & Technology

1993-01-25

Psychometrika, 47, 95-99. Raslear, T. G. (1983). A test of the Pfanzagl bisection model in rats. Journal of Experimental Psychology : Animal Behavior Processes, 9...temporal bisection, Y-maze, treadmill running, food motivation (behavioraleconomics), and Persolt swim test . Reliable effects were found with the...subsequent task performance: temporal bisection, Y-maze, treadmill running, food motivation (behavioral economics), and Porsolt swim test . Reliable effects

Prism adaptation enhances activity of intact fronto-parietal areas in both hemispheres in neglect patients.

PubMed

Saj, Arnaud; Cojan, Yann; Vocat, Roland; Luauté, Jacques; Vuilleumier, Patrik

2013-01-01

Unilateral spatial neglect involves a failure to report or orient to stimuli in the contralesional (left) space due to right brain damage, with severe handicap in everyday activities and poor rehabilitation outcome. Because behavioral studies suggest that prism adaptation may reduce spatial neglect, we investigated the neural mechanisms underlying prism effects on visuo-spatial processing in neglect patients. We used functional magnetic resonance imaging (fMRI) to examine the effect of (right-deviating) prisms on seven patients with left neglect, by comparing brain activity while they performed three different spatial tasks on the same visual stimuli (bisection, search, and memory), before and after a single prism-adaptation session. Following prism adaptation, fMRI data showed increased activation in bilateral parietal, frontal, and occipital cortex during bisection and visual search, but not during the memory task. These increases were associated with significant behavioral improvement in the same two tasks. Changes in neural activity and behavior were seen only after prism adaptation, but not attributable to mere task repetition. These results show for the first time the neural substrates underlying the therapeutic benefits of prism adaptation, and demonstrate that visuo-motor adaptation induced by prism exposure can restore activation in bilateral brain networks controlling spatial attention and awareness. This bilateral recruitment of fronto-parietal networks may counteract the pathological biases produced by unilateral right hemisphere damage, consistent with recent proposals that neglect may reflect lateralized deficits induced by bilateral hemispheric dysfunction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Cellular composition and viability of demi- and quarter-embryos made from bisected bovine morulae and blastocysts produced in vitro.

PubMed

Rho, G J; Johnson, W H; Betteridge, K J

1998-10-15

The cellular composition and viability of intact, IVP embryos were compared with those of demi- and quarter-embryos produced by bisection of IVP morulae and blastocysts. Embryos were produced by established techniques from oocytes harvested from slaughterhouse ovaries. In Experiment 1, morulae at Day 6 or blastocysts at Day 7 were bisected on an inverted microscope using a microsurgical steel blade. Demi-embryos were then cultured without a zona pellucida until Day 8, when they were morphologically assessed for quality (viability). A higher proportion of demi-embryos made from blastocysts than from morulae were classified as viable (381/420, 91% vs 164/267, 61%; P < 0.001). In Experiment 2, only Day 7 blastocysts were bisected, and some of the resulting demi-embryos were bisected a second time 24 h later to produce quarter-embryos. The remaining demi-embryos, the quarter-embryos, and control intact embryos were cultured until Day 9, at which time they were assessed for quality and subjected to immunosurgery and differential staining to count inner cell mass (ICM) and trophectoderm cells. A higher proportion of demi-embryos than quarter-embryos was classified as viable (408/459, 89% vs 223/319, 70%, respectively; P < 0.001). Total cell numbers decreased with successive bisections, but the proportion of surviving cells found in the ICM was significantly (P < 0.05) higher in the best quality demi- and quarter-embryos (35 and 32%, respectively) than in the controls (22%). Transfer of all 12 quarter-embryos derived from 3 blastocysts, in pairs, into 6 recipient heifers resulted in 2 pregnancies, each with a single viable fetus at 90 d of gestation. The fetuses originated from 2 different blastocysts. The results suggest that bisection of intact IVP embryos into demi-embryos and bisection of those into quarter-embryos can increase the number of transferable embryos by as much as 178 and 235%, respectively.

Developing a semi/automated protocol to post-process large volume, High-resolution airborne thermal infrared (TIR) imagery for urban waste heat mapping

NASA Astrophysics Data System (ADS)

Rahman, Mir Mustafizur

In collaboration with The City of Calgary 2011 Sustainability Direction and as part of the HEAT (Heat Energy Assessment Technologies) project, the focus of this research is to develop a semi/automated 'protocol' to post-process large volumes of high-resolution (H-res) airborne thermal infrared (TIR) imagery to enable accurate urban waste heat mapping. HEAT is a free GeoWeb service, designed to help Calgary residents improve their home energy efficiency by visualizing the amount and location of waste heat leaving their homes and communities, as easily as clicking on their house in Google Maps. HEAT metrics are derived from 43 flight lines of TABI-1800 (Thermal Airborne Broadband Imager) data acquired on May 13--14, 2012 at night (11:00 pm--5:00 am) over The City of Calgary, Alberta (˜825 km 2) at a 50 cm spatial resolution and 0.05°C thermal resolution. At present, the only way to generate a large area, high-spatial resolution TIR scene is to acquire separate airborne flight lines and mosaic them together. However, the ambient sensed temperature within, and between flight lines naturally changes during acquisition (due to varying atmospheric and local micro-climate conditions), resulting in mosaicked images with different temperatures for the same scene components (e.g. roads, buildings), and mosaic join-lines arbitrarily bisect many thousands of homes. In combination these effects result in reduced utility and classification accuracy including, poorly defined HEAT Metrics, inaccurate hotspot detection and raw imagery that are difficult to interpret. In an effort to minimize these effects, three new semi/automated post-processing algorithms (the protocol) are described, which are then used to generate a 43 flight line mosaic of TABI-1800 data from which accurate Calgary waste heat maps and HEAT metrics can be generated. These algorithms (presented as four peer-reviewed papers)---are: (a) Thermal Urban Road Normalization (TURN)---used to mitigate the microclimatic variability within a thermal flight line based on varying road temperatures; (b) Automated Polynomial Relative Radiometric Normalization (RRN)---which mitigates the between flight line radiometric variability; and (c) Object Based Mosaicking (OBM)---which minimizes the geometric distortion along the mosaic edge between each flight line. A modified Emissivity Modulation technique is also described to correct H-res TIR images for emissivity. This combined radiometric and geometric post-processing protocol (i) increases the visual agreement between TABI-1800 flight lines, (ii) improves radiometric agreement within/between flight lines, (iii) produces a visually seamless mosaic, (iv) improves hot-spot detection and landcover classification accuracy, and (v) provides accurate data for thermal-based HEAT energy models. Keywords: Thermal Infrared, Post-Processing, High Spatial Resolution, Airborne, Thermal Urban Road Normalization (TURN), Relative Radiometric Normalization (RRN), Object Based Mosaicking (OBM), TABI-1800, HEAT, and Automation.

Environmental surfaces and the compression of perceived visual space

PubMed Central

Bian, Zheng; Andersen, George J.

2011-01-01

The present study examined whether the compression of perceived visual space varies according to the type of environmental surface being viewed. To examine this issue, observers made exocentric distance judgments when viewing simulated 3D scenes. In 4 experiments, observers viewed ground and ceiling surfaces and performed either an L-shaped matching task (Experiments 1, 3, and 4) or a bisection task (Experiment 2). Overall, we found considerable compression of perceived exocentric distance on both ground and ceiling surfaces. However, the perceived exocentric distance was less compressed on a ground surface than on a ceiling surface. In addition, this ground surface advantage did not vary systematically as a function of the distance in the scene. These results suggest that the perceived visual space when viewing a ground surface is less compressed than the perceived visual space when viewing a ceiling surface and that the perceived layout of a surface varies as a function of the type of the surface. PMID:21669858

Projecting one’s own spatial bias onto others during a theory-of-mind task

PubMed Central

Bio, Branden J.; Webb, Taylor W.; Graziano, Michael S. A.

2018-01-01

Many people show a left-right bias in visual processing. We measured spatial bias in neurotypical participants using a variant of the line bisection task. In the same participants, we measured performance in a social cognition task. This theory-of-mind task measured whether each participant had a processing-speed bias toward the right of, or left of, a cartoon agent about which the participant was thinking. Crucially, the cartoon was rotated such that what was left and right with respect to the cartoon was up and down with respect to the participant. Thus, a person’s own left-right bias could not align directly onto left and right with respect to the cartoon head. Performance on the two tasks was significantly correlated. People who had a natural bias toward processing their own left side of space were quicker to process how the cartoon might think about objects to the left side of its face, and likewise for a rightward bias. One possible interpretation of these results is that the act of processing one’s own personal space shares some of the same underlying mechanisms as the social cognitive act of reconstructing someone else’s processing of their space. PMID:29339513

Rapid natural scene categorization in the near absence of attention

PubMed Central

Li, Fei Fei; VanRullen, Rufin; Koch, Christof; Perona, Pietro

2002-01-01

What can we see when we do not pay attention? It is well known that we can be “blind” even to major aspects of natural scenes when we attend elsewhere. The only tasks that do not need attention appear to be carried out in the early stages of the visual system. Contrary to this common belief, we report that subjects can rapidly detect animals or vehicles in briefly presented novel natural scenes while simultaneously performing another attentionally demanding task. By comparison, they are unable to discriminate large T's from L's, or bisected two-color disks from their mirror images under the same conditions. We conclude that some visual tasks associated with “high-level” cortical areas may proceed in the near absence of attention. PMID:12077298

Regeneration in bipinnaria larvae of the bat star Patiria miniata induces rapid and broad new gene expression.

PubMed

Oulhen, Nathalie; Heyland, Andreas; Carrier, Tyler J; Zazueta-Novoa, Vanesa; Fresques, Tara; Laird, Jessica; Onorato, Thomas M; Janies, Daniel; Wessel, Gary

2016-11-01

Some metazoa have the capacity to regenerate lost body parts. This phenomenon in adults has been classically described in echinoderms, especially in sea stars (Asteroidea). Sea star bipinnaria larvae can also rapidly and effectively regenerate a complete larva after surgical bisection. Understanding the capacity to reverse cell fates in the larva is important from both a developmental and biomedical perspective; yet, the mechanisms underlying regeneration in echinoderms are poorly understood. Here, we describe the process of bipinnaria regeneration after bisection in the bat star Patiria miniata. We tested transcriptional, translational, and cell proliferation activity after bisection in anterior and posterior bipinnaria halves as well as expression of SRAP, reported as a sea star regeneration associated protease (Vickery et al., 2001b). Moreover, we found several genes whose transcripts increased in abundance following bisection, including: Vasa, dysferlin, vitellogenin 1 and vitellogenin 2. These results show a transformation following bisection, especially in the anterior halves, of cell fate reassignment in all three germ layers, with clear and predictable changes. These results define molecular events that accompany the cell fate changes coincident to the regenerative response in echinoderm larvae. Crown Copyright © 2016. Published by Elsevier Ireland Ltd. All rights reserved.

Reading direction shifts visuospatial attention: an Interactive Account of attentional biases.

PubMed

Rinaldi, Luca; Di Luca, Samuel; Henik, Avishai; Girelli, Luisa

2014-09-01

A growing amount of evidence confirms the influence of reading and writing habits on visuospatial processing, although this phenomenon has been so far testified mainly as a lateralized shift of a single behavioral sign (e.g., line bisection), with lack of proof from pure right-to-left readers. The present study contributed to this issue by analyzing multiple attentional and motor indexes in monolingual Italian (i.e., reading from left-to-right), and monolingual (i.e., reading from right-to-left) and bilingual Israeli (i.e., reading from right-to-left in Hebrew but also from left-to-right in English) participants' visuospatial performance. Subjects were administered a computerized standard star cancellation task and a modified version in which English letters and words were replaced by Hebrew ones. Tasks were presented on a graphics tablet, allowing recording of both chronometric and spatial parameters (i.e., measured in (x, y) vector coordinates). Results showed that reading direction modulated the on-line visuomotor performance (i.e., left-to-right vs. right-to-left shifts) from the beginning (i.e., first mark) to the end of the task (i.e., spatial distribution of omissions and subjective epicenter). Additionally, the spatial bias observed in a computerized line bisection task was also related to the participants' habitual reading direction. Overall, the results favor the proposal of an Interactive Account of visuospatial asymmetries, according to which both cultural factors, such as the directional scanning associated with language processing, and biological factors, such as hemispheric specialization, modulate visuospatial processing. Results are discussed in light of recent behavioral and neuroanatomical findings. Copyright © 2014 Elsevier B.V. All rights reserved.

A Parallel Implementation of Multilevel Recursive Spectral Bisection for Application to Adaptive Unstructured Meshes. Chapter 1

NASA Technical Reports Server (NTRS)

Barnard, Stephen T.; Simon, Horst; Lasinski, T. A. (Technical Monitor)

1994-01-01

The design of a parallel implementation of multilevel recursive spectral bisection is described. The goal is to implement a code that is fast enough to enable dynamic repartitioning of adaptive meshes.

Hazardous Waste Cleanup: Unilever Bestfoods in Montville, New Jersey

EPA Pesticide Factsheets

Unilever Bestfoods area is approximately 27 acres and is bisected by Taylortown Road into eastern and western sections. Crooked Brook further bisects the western portion of the site into northern and southern sections in Montville, New Jersey.

Accuracy and Feasibility of an Android-Based Digital Assessment Tool for Post Stroke Visual Disorders-The StrokeVision App.

PubMed

Quinn, Terence J; Livingstone, Iain; Weir, Alexander; Shaw, Robert; Breckenridge, Andrew; McAlpine, Christine; Tarbert, Claire M

2018-01-01

Visual impairment affects up to 70% of stroke survivors. We designed an app (StrokeVision) to facilitate screening for common post stroke visual issues (acuity, visual fields, and visual inattention). We sought to describe the test time, feasibility, acceptability, and accuracy of our app-based digital visual assessments against (a) current methods used for bedside screening and (b) gold standard measures. Patients were prospectively recruited from acute stroke settings. Index tests were app-based assessments of fields and inattention performed by a trained researcher. We compared against usual clinical screening practice of visual fields to confrontation, including inattention assessment (simultaneous stimuli). We also compared app to gold standard assessments of formal kinetic perimetry (Goldman or Octopus Visual Field Assessment); and pencil and paper-based tests of inattention (Albert's, Star Cancelation, and Line Bisection). Results of inattention and field tests were adjudicated by a specialist Neuro-ophthalmologist. All assessors were masked to each other's results. Participants and assessors graded acceptability using a bespoke scale that ranged from 0 (completely unacceptable) to 10 (perfect acceptability). Of 48 stroke survivors recruited, the complete battery of index and reference tests for fields was successfully completed in 45. Similar acceptability scores were observed for app-based [assessor median score 10 (IQR: 9-10); patient 9 (IQR: 8-10)] and traditional bedside testing [assessor 10 (IQR: 9-10); patient 10 (IQR: 9-10)]. Median test time was longer for app-based testing [combined time to completion of all digital tests 420 s (IQR: 390-588)] when compared with conventional bedside testing [70 s, (IQR: 40-70)], but shorter than gold standard testing [1,260 s, (IQR: 1005-1,620)]. Compared with gold standard assessments, usual screening practice demonstrated 79% sensitivity and 82% specificity for detection of a stroke-related field defect. This compares with 79% sensitivity and 88% specificity for StrokeVision digital assessment. StrokeVision shows promise as a screening tool for visual complications in the acute phase of stroke. The app is at least as good as usual screening and offers other functionality that may make it attractive for use in acute stroke. https://ClinicalTrials.gov/ct2/show/NCT02539381.

Type of Material in the Pipes Overhead Power Lines Impact on the Distribution on the Size of the Overhang and the Tension

NASA Astrophysics Data System (ADS)

Pawlak, Urszula; Pawlak, Marcin

2017-10-01

The article presents the material type from which the conductors of the overhead power lines are produced influences on the size of the overhang and the tension. The aim of the calculations was to present the benefits of the mechanics of the cable resulting from the type of cable used. The analysis was performed for two types of cables: aluminium with steel core and aluminium with composite core, twice span power line section. 10 different conductor-to-strand coil, wind, icing, and temperature variations were included in the calculations. The string description was made by means of a chain curve, while the horizontal component H of the tension force was determined using the bisection method. The loads were collected in accordance with applicable Eurocode.

Spatial range of illusory effects in Müller-Lyer figures.

PubMed

Predebon, J

2001-11-01

The spatial range of the illusory effects in Müller-Lyer (M-L) figures was examined in three experiments. Experiments 1 and 2 assessed the pattern of bisection errors along the shaft of the standard or double-angle (experiment 1) and the single-angle (experiment 2) M-L figures: Subjects bisected the shaft and the resulting two half-segments of the shaft to produce apparently equal quarters, and then each of the quarters to produce eight equal-appearing segments. The bisection judgments of each segment were referenced to the segment's physical midpoints. The expansion or wings-out and the contraction or wings-in figures yielded similar patterns of bisection errors. For the standard M-L figures, there were significant errors in bisecting each half, and each end-quarter, but not the two central quarters of the shaft. For the single-angle M-L figures, there were significant errors in bisecting the length of the shaft, the half-segment, and the quarter, of the shaft adjacent to the vertex but not the second quarter from the vertex nor in dividing the half of the shaft at the open end of the figure into four equal intervals. Experiment 3 assessed the apparent length of the half-segment of the shaft at the open end of the single-angle figures. Length judgments were unaffected by the vertex at the opposite end of the shaft. Taken together, the results indicate that the length distortions in both the standard and single-angle M-L figures are not uniformly distributed along the shaft but rather are confined mainly to the quarters adjacent to the vertices. The present findings imply that theories of the M-L illusion which assume uniform expansion or contraction of the shafts are incomplete.

In vitro and in vivo survival of bisected sheep embryos derived from frozen-thawed unsorted, and frozen-thawed sex-sorted and refrozen-thawed ram spermatozoa.

PubMed

Morton, Katherine M; Rowe, Anthony M; Chis Maxwell, W M; Evans, Gareth

2006-04-15

Ovine IVP embryos were derived from frozen-thawed unsorted and frozen-thawed sex-sorted spermatozoa that had been refrozen and thawed. The embryos were bisected and cultured in vitro, or transferred to recipient ewes to determine their survival in vitro and in vivo. Oocyte progression to the blastocyst stage was similar for unsorted (97/232, 41.8%) and sex-sorted spermatozoa (113/286, 39.5%; P > 0.05). Embryo survival in vitro post-bisection was similar for demi-embryos derived from unsorted and sex-sorted sperm, and embryos bisected at the blastocyst and expanded blastocyst stage (P > 0.05). A higher proportion of recipient ewes were pregnant at Day 63 after transfer of two intact embryos derived from unsorted (17/21, 80.9%) than two demi-embryos derived from unsorted (5/15, 33.3%) or sex-sorted spermatozoa (7/17, 41.2%). The number of fetuses per original embryo at Day 63 did not differ among groups (unsorted intact: 23/42, 54.8%; unsorted demi: 7/15, 46.7%; sex-sorted demi: 10/17, 58.8%) and twin pregnancies were observed in all groups. Embryo survival to term was high, and was not significantly different among intact (unsorted: 22/42, 52.4%) and demi-embryos (unsorted: 4/15, 26.7%; sex-sorted spermatozoa: 7/17, 41.2%; P > 0.05). Dizygotic twins (n = 6 sets) were born after the transfer of two intact embryos derived from unsorted spermatozoa, but only singleton lambs resulted from the transfer of demi-embryos. In conclusion, bisected IVP embryos successfully developed into morphologically normal lambs. However, embryo survival to term was neither increased nor decreased by embryo bisection.

Experimental design and analysis of JND test on coded image/video

NASA Astrophysics Data System (ADS)

Lin, Joe Yuchieh; Jin, Lina; Hu, Sudeng; Katsavounidis, Ioannis; Li, Zhi; Aaron, Anne; Kuo, C.-C. Jay

2015-09-01

The visual Just-Noticeable-Difference (JND) metric is characterized by the detectable minimum amount of two visual stimuli. Conducting the subjective JND test is a labor-intensive task. In this work, we present a novel interactive method in performing the visual JND test on compressed image/video. JND has been used to enhance perceptual visual quality in the context of image/video compression. Given a set of coding parameters, a JND test is designed to determine the distinguishable quality level against a reference image/video, which is called the anchor. The JND metric can be used to save coding bitrates by exploiting the special characteristics of the human visual system. The proposed JND test is conducted using a binary-forced choice, which is often adopted to discriminate the difference in perception in a psychophysical experiment. The assessors are asked to compare coded image/video pairs and determine whether they are of the same quality or not. A bisection procedure is designed to find the JND locations so as to reduce the required number of comparisons over a wide range of bitrates. We will demonstrate the efficiency of the proposed JND test, report experimental results on the image and video JND tests.

No inherent left and right side in human 'mental number line': evidence from right brain damage.

PubMed

Aiello, Marilena; Jacquin-Courtois, Sophie; Merola, Sheila; Ottaviani, Teresa; Tomaiuolo, Francesco; Bueti, Domenica; Rossetti, Yves; Doricchi, Fabrizio

2012-08-01

Spatial reasoning has a relevant role in mathematics and helps daily computational activities. It is widely assumed that in cultures with left-to-right reading, numbers are organized along the mental equivalent of a ruler, the mental number line, with small magnitudes located to the left of larger ones. Patients with right brain damage can disregard smaller numbers while mentally setting the midpoint of number intervals. This has been interpreted as a sign of spatial neglect for numbers on the left side of the mental number line and taken as a strong argument for the intrinsic left-to-right organization of the mental number line. Here, we put forward the understanding of this cognitive disability by discovering that patients with right brain damage disregard smaller numbers both when these are mapped on the left side of the mental number line and on the right side of an imagined clock face. This shows that the right hemisphere supports the representation of small numerical magnitudes independently from their mapping on the left or the right side of a spatial-mental layout. In addition, the study of the anatomical correlates through voxel-based lesion-symptom mapping and the mapping of lesion peaks on the diffusion tensor imaging-based reconstruction of white matter pathways showed that the rightward bias in the imagined clock-face was correlated with lesions of high-level middle temporal visual areas that code stimuli in object-centred spatial coordinates, i.e. stimuli that, like a clock face, have an inherent left and right side. In contrast, bias towards higher numbers on the mental number line was linked to white matter damage in the frontal component of the parietal-frontal number network. These anatomical findings show that the human brain does not represent the mental number line as an object with an inherent left and right side. We conclude that the bias towards higher numbers in the mental bisection of number intervals does not depend on left side spatial, imagery or object-centred neglect and that it rather depends on disruption of an abstract non-spatial representation of small numerical magnitudes.

Observed Human Errors in Interpreting 3D visualizations: implications for Teaching Students how to Comprehend Geological Block Diagrams

NASA Astrophysics Data System (ADS)

Bemis, K. G.; Pirl, E.; Chiang, J.; Tremaine, M.

2009-12-01

Block diagrams are commonly used to communicate three dimensional geological structures and other phenomena relevant to geological science (e.g., water bodies in the ocean). However, several recent studies have suggested that these 3D visualizations create difficulties for individuals with low to moderate spatial abilities. We have therefore initiated a series of studies to understand what it is about the 3D structures that make them so difficult for some people and also to determine if we can improve people’s understanding of these structures through web-based training not related to geology or other underlying information. Our first study examined what mistakes subjects made in a set of 3D block diagrams designed to represent progressively more difficult internal structures. Each block was shown bisected by a plane either perpendicular or at an angle to the block sides. Five low to medium spatial subjects were asked to draw the features that would appear on the bisecting plane. They were asked to talk aloud as they solved the problem. Each session was videotaped. Using the time it took subjects to solve the problems, the subject verbalizations of their problem solving and the drawings that were found to be in error, we have been able to find common patterns in the difficulties the subjects had with the diagrams. We have used these patterns to generate a set of strategies the subjects used in solving the problems. From these strategies, we are developing methods of teaching. A problem found in earlier work on geology structures was not observed in our study, that is, one of subjects failing to recognize the 2D representation of the block as 3D and drawing the cross-section as a combined version of the visible faces of the object. We attribute this to our experiment introduction, suggesting that even this simple training needs to be carried out with students encountering 3D block diagrams. Other problems subjects had included difficulties in perceptually recognizing variations in layer thicknesses, difficulties in recognizing an internal structure from the visible cues on the block walls, difficulties in mentally constructing objects and intersections that were not perpendicular, and difficulties in keeping track of the number of folds of a layer, and thus, the number of intersections of the layer with the bisecting plane. All of these problems suggest that web-based games giving mass practice with these variations in block diagram representations are likely to give any person appropriate skills in their interpretation. The time to complete the drawings and the errors in the drawings were also correlated with quantifiable properties of the diagrams, e.g., number of layers, number of folds in the layers, angle of bisection of the plane, etc. These will be used in further research to organize the training from easy to hard problems following what is known already about mass practice and developing abstracted skill sets. The plan is to also make the training adaptive, that is, to provide practice in those areas where an individual user is having the most problems.

Proceedings of Border Institute VI: transboundary ecosystem management

Treesearch

D. Rick Van Schoik

2005-01-01

Ecosystems are bisected by international borders along the United States-Mexican border; infrastructure and the heightened security activities bisect the north-south cores, corridors, and buffers essential to preservation of ecosystems. The Southwest Consortium for Environmental Research and Policy (SCERP) and its partners convened an annual policy conference, Border...

Human Performance on the Temporal Bisection Task

ERIC Educational Resources Information Center

Kopec, Charles D.; Brody, Carlos D.

2010-01-01

The perception and processing of temporal information are tasks the brain must continuously perform. These include measuring the duration of stimuli, storing duration information in memory, recalling such memories, and comparing two durations. How the brain accomplishes these tasks, however, is still open for debate. The temporal bisection task,…

Suspension system for a wheel rolling on a flat track. [bearings for directional antennas

NASA Technical Reports Server (NTRS)

Mcginness, H. D. (Inventor)

1981-01-01

An improved suspension system for an uncrowned wheel rolling on a flat track is presented. It is characterized by a wheel frame assembly including a wheel frame and at least one uncrowned wheel connected in supporting relation with the frame. It is adapted to be seated in rolling engagement with a flat track, a load supporting bed, and a plurality of flexural struts interconnecting the bed in supported relation with the frame. Each of said struts is disposed in a plane passing through the center of the uncrowned wheel surface along a line substantially bisecting the line of contact established between the wheel surface and the flat surface of the truck and characterized by a modulus of elasticity sufficient for maintaining the axis of rotation for the wheel in substantial parallelism with the line of contact established between the surfaces of the wheel and track.

Mirror therapy in unilateral neglect after stroke (MUST trial): a randomized controlled trial.

PubMed

Pandian, Jeyaraj D; Arora, Rajni; Kaur, Paramdeep; Sharma, Deepika; Vishwambaran, Dheeraj K; Arima, Hisatomi

2014-09-09

We explored the effectiveness of mirror therapy (MT) in the treatment of unilateral neglect in stroke patients. This is an open, blinded endpoint, randomized controlled trial carried out from January 2011 to August 2013. We included stroke patients with thalamic and parietal lobe lesions with unilateral neglect 48 hours after stroke. Patients were randomized to the MT group or the control group (sham MT), and both the groups received limb activation. Patients received treatment for 1-2 hours a day 5 days a week for 4 weeks. The primary outcome was unilateral neglect assessed by a blinded assessor using the star cancellation test, the line bisection test, and a picture identification task at 1, 3, and 6 months. This study was registered at http://clinicaltrials.gov (NCT 01735877). Forty-eight patients were randomized to MT (n = 27) or the control group (n = 21). Improvement in scores on the star cancellation test over 6 months was greater in the MT group (mean difference 23, 95% confidence interval [CI] 19-28; p < 0.0001). Similarly, improvement in the MT group was observed in the scores on the picture identification task (mean difference 3.2, 95% CI 2.4-4.0; p < 0.0001) and line bisection test (mean difference 8.6, 95% CI 2.7-14.6; p = 0.006). In patients with stroke, MT is a simple treatment that improves unilateral neglect. This study provides Class I evidence that for patients with neglect from thalamic and parietal lobe strokes, MT improves neglect. © 2014 American Academy of Neurology.

Mirror Therapy in Unilateral Neglect After Stroke (MUST trial)

PubMed Central

Arora, Rajni; Kaur, Paramdeep; Sharma, Deepika; Vishwambaran, Dheeraj K.; Arima, Hisatomi

2014-01-01

Objective: We explored the effectiveness of mirror therapy (MT) in the treatment of unilateral neglect in stroke patients. Methods: This is an open, blinded endpoint, randomized controlled trial carried out from January 2011 to August 2013. We included stroke patients with thalamic and parietal lobe lesions with unilateral neglect 48 hours after stroke. Patients were randomized to the MT group or the control group (sham MT), and both the groups received limb activation. Patients received treatment for 1–2 hours a day 5 days a week for 4 weeks. The primary outcome was unilateral neglect assessed by a blinded assessor using the star cancellation test, the line bisection test, and a picture identification task at 1, 3, and 6 months. This study was registered at http://clinicaltrials.gov (NCT 01735877). Results: Forty-eight patients were randomized to MT (n = 27) or the control group (n = 21). Improvement in scores on the star cancellation test over 6 months was greater in the MT group (mean difference 23, 95% confidence interval [CI] 19–28; p < 0.0001). Similarly, improvement in the MT group was observed in the scores on the picture identification task (mean difference 3.2, 95% CI 2.4–4.0; p < 0.0001) and line bisection test (mean difference 8.6, 95% CI 2.7–14.6; p = 0.006). Conclusions: In patients with stroke, MT is a simple treatment that improves unilateral neglect. Classification of evidence: This study provides Class I evidence that for patients with neglect from thalamic and parietal lobe strokes, MT improves neglect. PMID:25107877

Lucky numbers: spatial neglect affects physical, but not representational, choices in a lotto task.

PubMed

Loetscher, Tobias; Nicholls, Michael E R; Towse, John N; Bradshaw, John L; Brugger, Peter

2010-05-01

Spatial neglect can be characterized by a "magnetic attraction" towards the right side of a visual stimulus array and a selection of stimuli from that hemispace. This study examined whether these distinctive characteristics in visuo-motor space are also evident in representational number space. Given that numbers are thought to be represented along a left-to-right oriented mental number line, an affinity for the spontaneous selection of larger numbers was anticipated for neglect patients. Contrary to this expectation, neglect patients (n=20) picked a similar range of numbers compared to controls (n=17) when generating a number between 1000 and 10,000 and when playing an imaginary lottery game. There was, however, a positive correlation between the biases for the imaginary lottery, number generation and a number bisection task - demonstrating that exploration asymmetries along the mental number line are consistent within individuals across tasks. Some of the patients selected smaller numbers in all of these tasks, confirming reports of dissociations between physical and numerical-representational forms of neglect. Conversely, only four (20%) of the patients could reliably be classified as demonstrating a neglect in number space. When filling out a physical lottery ticket, the neglect patients showed the expected bias towards picking numbers placed on the right-hand side of the ticket. These results demonstrate that the magnetic attraction towards the right side of mental representations is rather weak and that representational forms of neglect only occasionally co-exist with neglect in physical space. Copyright 2009 Elsevier Srl. All rights reserved.

Ipsilesional 'where' with contralesional 'what' neglect.

PubMed

Kwon, Jay Cheol; Ahn, Sunyoung; Kim, Sunghee; Heilman, Kenneth M

2012-01-01

Whereas contralesional spatial neglect is usually caused by right temporo-parietal lesions, ipsilesional spatial neglect is induced primarily by right frontal lesions. This report describes a 73-year-old woman with a right inferior parietal lesion who on 'where' tasks (line bisection and midline pointing) demonstrated ipsilesional neglect, but on 'what' tests (gap vs. no-gap detection cancellation and clothing tape removal) demonstrated contralesional neglect. This 'what' and 'where' directional dissociation provides evidence for independent 'what' and 'where' attentional networks; however, the reason this parietal lesion causes this contralesional vs. ipsilesional spatial attentional 'what' and 'where' dichotomy remains to be determined.

Dewitt Clinton High School Project BISECT. O.E.E. Evaluation Report, 1982-1983.

ERIC Educational Resources Information Center

Zephirin, Henriot; Schulman, Robert

Project Bilingual Spanish-to-English Career Training (BISECT) in its first year of funding offered bilingual instruction, career awareness development, and supportive services to 255 Hispanic students of limited English proficiency. Title VII, Title I, and tax-levy funds supported the program, which was implemented at DeWitt Clinton High School…

Orientation and spread of reconnection x-line in asymmetric current sheets

NASA Astrophysics Data System (ADS)

Liu, Y. H.; Hesse, M.; Wendel, D. E.; Kuznetsova, M.; Wang, S.

2017-12-01

The magnetic field in solar wind plasmas can shear with Earth's dipole magnetic field at arbitrary angles, and the plasma conditions on the two sides of the (magnetopause) current sheet can greatly differ. One of the outstanding questions in such asymmetric geometry is what local physics controls the orientation of the reconnection x-line; while the x-line in a simplified 2D model (simulation) always points out of the simulation plane by design, it is unclear how to predict the orientation of the x-line in a fully three-dimensional (3D) system. Using kinetic simulations run on Blue Waters, we develop an approach to explore this 3D nature of the reconnection x-line, and test hypotheses including maximizing the reconnection rate, tearing mode growth rate or reconnection outflow speed, and the bisection solution. Practically, this orientation should correspond to the M-direction of the local LMN coordinate system that is often employed to analyze diffusion region crossings by the Magnetospheric Multiscale Mission (MMS). In this talk, we will also discuss how an x-line spread from a point source in asymmetric geometries, and the boundary effect on the development of the reconnection x-line and turbulence.

Temporal processing dysfunction in schizophrenia.

PubMed

Carroll, Christine A; Boggs, Jennifer; O'Donnell, Brian F; Shekhar, Anantha; Hetrick, William P

2008-07-01

Schizophrenia may be associated with a fundamental disturbance in the temporal coordination of information processing in the brain, leading to classic symptoms of schizophrenia such as thought disorder and disorganized and contextually inappropriate behavior. Despite the growing interest and centrality of time-dependent conceptualizations of the pathophysiology of schizophrenia, there remains a paucity of research directly examining overt timing performance in the disorder. Accordingly, the present study investigated timing in schizophrenia using a well-established task of time perception. Twenty-three individuals with schizophrenia and 22 non-psychiatric control participants completed a temporal bisection task, which required participants to make temporal judgments about auditory and visually presented durations ranging from 300 to 600 ms. Both schizophrenia and control groups displayed greater visual compared to auditory timing variability, with no difference between groups in the visual modality. However, individuals with schizophrenia exhibited less temporal precision than controls in the perception of auditory durations. These findings correlated with parameter estimates obtained from a quantitative model of time estimation, and provide evidence of a fundamental deficit in temporal auditory precision in schizophrenia.

Pluto Color Map

NASA Image and Video Library

2017-01-20

This new, detailed global mosaic color map of Pluto is based on a series of three color filter images obtained by the Ralph/Multispectral Visual Imaging Camera aboard New Horizons during the NASA spacecraft's close flyby of Pluto in July 2015. The mosaic shows how Pluto's large-scale color patterns extend beyond the hemisphere facing New Horizons at closest approach- which were imaged at the highest resolution. North is up; Pluto's equator roughly bisects the band of dark red terrains running across the lower third of the map. Pluto's giant, informally named Sputnik Planitia glacier - the left half of Pluto's signature "heart" feature -- is at the center of this map. http://photojournal.jpl.nasa.gov/catalog/PIA11707

The role of primary auditory and visual cortices in temporal processing: A tDCS approach.

PubMed

Mioni, G; Grondin, S; Forgione, M; Fracasso, V; Mapelli, D; Stablum, F

2016-10-15

Many studies showed that visual stimuli are frequently experienced as shorter than equivalent auditory stimuli. These findings suggest that timing is distributed across many brain areas and that "different clocks" might be involved in temporal processing. The aim of this study is to investigate, with the application of tDCS over V1 and A1, the specific role of primary sensory cortices (either visual or auditory) in temporal processing. Forty-eight University students were included in the study. Twenty-four participants were stimulated over A1 and 24 participants were stimulated over V1. Participants performed time bisection tasks, in the visual and the auditory modalities, involving standard durations lasting 300ms (short) and 900ms (long). When tDCS was delivered over A1, no effect of stimulation was observed on perceived duration but we observed higher temporal variability under anodic stimulation compared to sham and higher variability in the visual compared to the auditory modality. When tDCS was delivered over V1, an under-estimation of perceived duration and higher variability was observed in the visual compared to the auditory modality. Our results showed more variability of visual temporal processing under tDCS stimulation. These results suggest a modality independent role of A1 in temporal processing and a modality specific role of V1 in the processing of temporal intervals in the visual modality. Copyright © 2016 Elsevier B.V. All rights reserved.

The Sloan Digital Sky Survey Reverberation Mapping Project: The C IV Blueshift, Its Variability, and Its Dependence Upon Quasar Properties

NASA Astrophysics Data System (ADS)

Sun, Mouyuan; Xue, Yongquan; Richards, Gordon T.; Trump, Jonathan R.; Shen, Yue; Brandt, W. N.; Schneider, D. P.

2018-02-01

We use the multi-epoch spectra of 362 quasars from the Sloan Digital Sky Survey Reverberation Mapping project to investigate the dependence of the blueshift of C IV relative to Mg II on quasar properties. We confirm that high-blueshift sources tend to have low C IV equivalent widths (EWs), and that the low-EW sources span a range of blueshift. Other high-ionization lines, such as He II, also show similar blueshift properties. The ratio of the line width (measured as both the full width at half maximum and the velocity dispersion) of C IV to that of Mg II increases with blueshift. Quasar variability enhances the connection between the C IV blueshift and quasar properties (e.g., EW). The variability of the Mg II line center (i.e., the wavelength that bisects the cumulative line flux) increases with blueshift. In contrast, the C IV line center shows weaker variability at the extreme blueshifts. Quasars with the high-blueshift C IV lines tend to have less variable continuum emission, when controlling for EW, luminosity, and redshift. Our results support the scenario that high-blueshift sources tend to have large Eddington ratios.

The NRL Program on Electroactive Polymers.

DTIC Science & Technology

1980-09-15

cell of a point in an aggregate involves selecting the smallest cell formed by planes perpendicularly bisecting all the point to neighbor vectors . Such...plane perpendicular to the interatomic vector is located nearer the smaller atom by bisecting the distance between the sur- faces of spheres whose...density waves (and consequent novel excitations such as solitons (6)). The physical structure as well as the chemical bonding of such polymeric

Tourism Impacts of Three Mile Island and Other Adverse Events: Implications for Lincoln County and Other Rural Counties Bisected by Radioactive Wastes Intended for Yucca Mountain.

ERIC Educational Resources Information Center

Himmelberger, Jeffery J.; And Others

1995-01-01

Summarizes key research implications of Three Mile Island and other major hazard events as related to tourism. Examines how the proposed Yucca Mountain nuclear waste repository system will impact tourism in southern Nevada and other visitor-oriented rural counties bisected by planned waste transportation corridors. (AIM)

Cultural and biological factors modulate spatial biases over development.

PubMed

Girelli, Luisa; Marinelli, Chiara Valeria; Grossi, Giuseppe; Arduino, Lisa S

2017-11-01

Increasing evidence supports the contribution of both biological and cultural factors to visuospatial processing. The present study adds to the literature by exploring the interplay of perceptual and linguistic mechanisms in determining visuospatial asymmetries in adults (Experiment 1) and children (Experiment 2). In particular, pre-schoolers (3 and 5 year-olds), school-aged children (8 year-old), and adult participants were required to bisect different types of stimuli, that is, lines, words, and figure strings. In accordance with the literature, results yielded a leftward bias for lines and words and a rightward bias for figure strings, in adult participants. More critically, different biases were found for lines, words, and figure strings in children as a function of age, reflecting the impact of both cultural and biological factors on the processing of different visuospatial materials. Specifically, an adult-like pattern of results emerged only in the older group of children (8 year-old), but not in pre-schoolers. Results are discussed in terms of literacy, reading habits exposure, and biological maturation.

Influence of "Solcoseryl" during culture on the sex-dependent repair of bovine demi-embryos.

PubMed

Tominaga, K; Yoneda, K; Utsumi, K

1996-03-01

The purpose of this experiment was to determine the effect of culture conditions on the development of split embryos after bisection and on the sex ratio of resultant bovine demi-embryos. Embryos that had developed into blastocysts on days 6 1/2 to 7 or on days 7 1/2 to 8 from oocytes matured and fertilized in vitro were bisected in BMOC-3 medium supplemented with 33% calf serum. The medium also contained 0%, 0.1% or 1.0% Solcoseryl, a deproteinized hemodialysate product from calf blood. The demi-embryos were first cultured for 4 hours in the same medium in which they had been bisected and then co-cultured with cumulus cells in TCM199 supplemented with 1% calf serum for an additional 20 hr. The rate of production of good to excellent quality demi-embryos obtained from days 6 1/2 to 7 blastocysts was higher than from those on days 7 1/2 to 8. The rate was also significantly improved when blastocysts were bisected in medium containing 0.1% or 1.0% Solcoseryl, compared to the medium without Solcoseryl. Male embryos seemed to recover more rapidly than female embryos, as assessed by morphological quality at 4 hr, although the quality of female embryos had improved by 24 hr. The percentage of males after culture was higher in the medium without Solcoseryl than in its presence. Thus, addition of Solcoseryl at either 0.1% or 1.0% to BMOC-3 medium seemed to improve the production efficiency of good quality demi-embryos, but did not influence the sex ratio. It appears as if female demi-embryos required more time than male embryos to be repaired after bisection.

Extended Wearing Trial of Trifield Lens Device for “Tunnel Vision”

PubMed Central

Woods, Russell L.; Giorgi, Robert G.; Berson, Eliot L.; Peli, Eli

2009-01-01

Severe visual field constriction (tunnel vision) impairs the ability to navigate and walk safely. We evaluated Trifield glasses as a mobility rehabilitation device for tunnel vision in an extended wearing trial. Twelve patients with tunnel vision (5 to 22 degrees wide) due to retinitis pigmentosa or choroideremia participated in the 5-visit wearing trial. To expand the horizontal visual field, one spectacle lens was fitted with two apex-to-apex prisms that vertically bisected the pupil on primary gaze. This provides visual field expansion at the expense of visual confusion (two objects with the same visual direction). Patients were asked to wear these spectacles as much as possible for the duration of the wearing trial (median 8, range 6 to 60, weeks). Clinical success (continued wear, indicating perceived overall benefit), visual field expansion, perceived direction and perceived visual ability were measured. Of 12 patients, 9 chose to continue wearing the Trifield glasses at the end of the wearing trial. Of those 9 patients, at long-term follow-up (35 to 78 weeks), 3 reported still wearing the Trifield glasses. Visual field expansion (median 18, range 9 to 38, degrees) was demonstrated for all patients. No patient demonstrated adaptation to the change in visual direction produced by the Trifield glasses (prisms). For difficulty with obstacles, some differences between successful and non-successful wearers were found. Trifield glasses provided reported benefits in obstacle avoidance to 7 of the 12 patients completing the wearing trial. Crowded environments were particularly difficult for most wearers. Possible reasons for long-term discontinuation and lack of adaptation to perceived direction are discussed. PMID:20444130

Extended wearing trial of Trifield lens device for 'tunnel vision'.

PubMed

Woods, Russell L; Giorgi, Robert G; Berson, Eliot L; Peli, Eli

2010-05-01

Severe visual field constriction (tunnel vision) impairs the ability to navigate and walk safely. We evaluated Trifield glasses as a mobility rehabilitation device for tunnel vision in an extended wearing trial. Twelve patients with tunnel vision (5-22 degrees wide) due to retinitis pigmentosa or choroideremia participated in the 5-visit wearing trial. To expand the horizontal visual field, one spectacle lens was fitted with two apex-to-apex prisms that vertically bisected the pupil on primary gaze. This provides visual field expansion at the expense of visual confusion (two objects with the same visual direction). Patients were asked to wear these spectacles as much as possible for the duration of the wearing trial (median 8, range 6-60 weeks). Clinical success (continued wear, indicating perceived overall benefit), visual field expansion, perceived direction and perceived visual ability were measured. Of 12 patients, nine chose to continue wearing the Trifield glasses at the end of the wearing trial. Of those nine patients, at long-term follow-up (35-78 weeks), three reported still wearing the Trifield glasses. Visual field expansion (median 18, range 9-38 degrees) was demonstrated for all patients. No patient demonstrated adaptation to the change in visual direction produced by the Trifield glasses (prisms). For reported difficulty with obstacles, some differences between successful and non-successful wearers were found. Trifield glasses provided reported benefits in obstacle avoidance to 7 of the 12 patients completing the wearing trial. Crowded environments were particularly difficult for most wearers. Possible reasons for long-term discontinuation and lack of adaptation to perceived direction are discussed.

Validation of an immersive virtual reality system for training near and far space neglect in individuals with stroke: a pilot study.

PubMed

Yasuda, Kazuhiro; Muroi, Daisuke; Ohira, Masahiro; Iwata, Hiroyasu

2017-10-01

Unilateral spatial neglect (USN) is defined as impaired ability to attend and see on one side, and when present, it interferes seriously with daily life. These symptoms can exist for near and far spaces combined or independently, and it is important to provide effective intervention for near and far space neglect. The purpose of this pilot study was to propose an immersive virtual reality (VR) rehabilitation program using a head-mounted display that is able to train both near and far space neglect, and to validate the immediate effect of the VR program in both near and far space neglect. Ten USN patients underwent the VR program with a pre-post design and no control. In the virtual environment, we developed visual searching and reaching tasks using an immersive VR system. Behavioral inattention test (BIT) scores obtained pre- and immediate post-VR program were compared. BIT scores obtained pre- and post-VR program revealed that far space neglect but not near space neglect improved promptly after the VR program. This effect for far space neglect was observed in the cancelation task, but not in the line bisection task. Positive effects of the immersive VR program for far space neglect are suggested by the results of the present pilot study. However, further studies with rigorous designs are needed to validate its clinical effectiveness.

Impaired spatial body representation in complex regional pain syndrome type 1 (CRPS I).

PubMed

Reinersmann, Annika; Landwehrt, Julia; Krumova, Elena K; Ocklenburg, Sebastian; Güntürkün, Onur; Maier, Christoph

2012-11-01

Recently, a shift of the visual subjective body midline (vSM), a correlate of the egocentric reference frame, towards the affected side was reported in patients with complex regional pain syndrome (CRPS). However, the specificity of this finding is as yet unclear. This study compares 24 CRPS patients to 21 patients with upper limb pain of other origin (pain control) and to 24 healthy subjects using a comprehensive test battery, including assessment of the vSM in light and dark, line bisection, hand laterality recognition, neglect-like severity symptoms, and motor impairment (disability of the arm, shoulder, and hand). 1-way analysis of variance, t-tests, significance level: 0.05. In the dark, CRPS patients displayed a significantly larger leftward spatial bias when estimating their vSM, compared to pain controls and healthy subjects, and also reported lower motor function than pain controls. For right-affected CRPS patients only, the deviation of the vSM correlated significantly with the severity of distorted body perception. Results confirm previous findings of impaired visuospatial perception in CRPS patients, which might be the result of the involvement of supraspinal mechanisms in this pain syndrome. These mechanisms might accentuate the leftward bias that results from a right-hemispheric dominance in visuospatial processing and is known as pseudoneglect. Pseudoneglect reveals itself in the tendency to perceive the midpoint of horizontal lines or the subjective body midline left of the centre. It was observable in all 3 groups, but most pronounced in CRPS patients, which might be due to the cortical reorganisation processes associated with this syndrome. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

It's about time: revisiting temporal processing deficits in dyslexia.

PubMed

Casini, Laurence; Pech-Georgel, Catherine; Ziegler, Johannes C

2018-03-01

Temporal processing in French children with dyslexia was evaluated in three tasks: a word identification task requiring implicit temporal processing, and two explicit temporal bisection tasks, one in the auditory and one in the visual modality. Normally developing children matched on chronological age and reading level served as a control group. Children with dyslexia exhibited robust deficits in temporal tasks whether they were explicit or implicit and whether they involved the auditory or the visual modality. First, they presented larger perceptual variability when performing temporal tasks, whereas they showed no such difficulties when performing the same task on a non-temporal dimension (intensity). This dissociation suggests that their difficulties were specific to temporal processing and could not be attributed to lapses of attention, reduced alertness, faulty anchoring, or overall noisy processing. In the framework of cognitive models of time perception, these data point to a dysfunction of the 'internal clock' of dyslexic children. These results are broadly compatible with the recent temporal sampling theory of dyslexia. © 2017 John Wiley & Sons Ltd.

Effect of bisecting GlcNAc and core fucosylation on conformational properties of biantennary complex-type N-glycans in solution.

PubMed

Nishima, Wataru; Miyashita, Naoyuki; Yamaguchi, Yoshiki; Sugita, Yuji; Re, Suyong

2012-07-26

The introduction of bisecting GlcNAc and core fucosylation in N-glycans is essential for fine functional regulation of glycoproteins. In this paper, the effect of these modifications on the conformational properties of N-glycans is examined at the atomic level by performing replica-exchange molecular dynamics (REMD) simulations. We simulate four biantennary complex-type N-glycans, namely, unmodified, two single-substituted with either bisecting GlcNAc or core fucose, and disubstituted forms. By using REMD as an enhanced sampling technique, five distinct conformers in solution, each of which is characterized by its local orientation of the Manα1-6Man glycosidic linkage, are observed for all four N-glycans. The chemical modifications significantly change their conformational equilibria. The number of major conformers is reduced from five to two and from five to four upon the introduction of bisecting GlcNAc and core fucosylation, respectively. The population change is attributed to specific inter-residue hydrogen bonds, including water-mediated ones. The experimental NMR data, including nuclear Overhauser enhancement and scalar J-coupling constants, are well reproduced taking the multiple conformers into account. Our structural model supports the concept of "conformer selection", which emphasizes the conformational flexibility of N-glycans in protein-glycan interactions.

A Chinese patient with pusher syndrome and unilateral spatial neglect syndrome.

PubMed

Chen, Xiao-Wei; Lin, Cheng-He; Zheng, Hua; Lin, Zhen-Lan

2014-07-01

To observe clinical manifestations, behavioral characteristics, and effects of rehabilitation on a patient with pusher syndrome and unilateral spatial neglect caused by right thalamic hemorrhage. Assessment of pusher syndrome was made by the Scale for Contraversive pushing (SCP), and unilateral spatial neglect syndrome was diagnosed using line cancellation, letter and star cancellation, line bisection tests and copy and continuation of graphic sequence test. Behavioral therapy, occupational therapy, reading training and traditional Chinese medicine methods were adopted for treatment of pusher syndrome and unilateral spatial neglect. The patient showed typical pusher syndrome and unilateral spatial neglect symptoms. The pusher syndrome and unilateral spatial neglect symptoms were significantly improved following rehabilitation treatments. Pusher syndrome and unilateral spatial neglect syndrome occurred simultaneously after right thalamic hemorrhage. Early rehabilitation therapy can reduce the symptoms of pusher syndrome and unilateral spatial neglect syndrome and improve motor function.

Human performance on the temporal bisection task.

PubMed

Kopec, Charles D; Brody, Carlos D

2010-12-01

The perception and processing of temporal information are tasks the brain must continuously perform. These include measuring the duration of stimuli, storing duration information in memory, recalling such memories, and comparing two durations. How the brain accomplishes these tasks, however, is still open for debate. The temporal bisection task, which requires subjects to compare temporal stimuli to durations held in memory, is perfectly suited to address these questions. Here we perform a meta-analysis of human performance on the temporal bisection task collected from 148 experiments spread across 18 independent studies. With this expanded data set we are able to show that human performance on this task contains a number of significant peculiarities, which in total no single model yet proposed has been able to explain. Here we present a simple 2-step decision model that is capable of explaining all the idiosyncrasies seen in the data. Copyright © 2010 Elsevier Inc. All rights reserved.

Achieving the Holevo bound via a bisection decoding protocol

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

Rosati, Matteo; Giovannetti, Vittorio

2016-06-15

We present a new decoding protocol to realize transmission of classical information through a quantum channel at asymptotically maximum capacity, achieving the Holevo bound and thus the optimal communication rate. At variance with previous proposals, our scheme recovers the message bit by bit, making use of a series of “yes-no” measurements, organized in bisection fashion, thus determining which codeword was sent in log{sub 2} N steps, N being the number of codewords.

Insulin/IGF-I Signaling Pathways Enhances Tumor Cell Invasion through Bisecting GlcNAc N-glycans Modulation. An Interplay with E-Cadherin

PubMed Central

Dias, Ana M.; Oliveira, Patrícia; Cabral, Joana; Seruca, Raquel; Oliveira, Carla; Morgado-Díaz, José Andrés; Reis, Celso A.; Pinho, Salomé S.

2013-01-01

Changes in glycosylation are considered a hallmark of cancer, and one of the key targets of glycosylation modifications is E-cadherin. We and others have previously demonstrated that E-cadherin has a role in the regulation of bisecting GlcNAc N-glycans expression, remaining to be determined the E-cadherin-dependent signaling pathway involved in this N-glycans expression regulation. In this study, we analysed the impact of E-cadherin expression in the activation profile of receptor tyrosine kinases such as insulin receptor (IR) and IGF-I receptor (IGF-IR). We demonstrated that exogenous E-cadherin expression inhibits IR, IGF-IR and ERK 1/2 phosphorylation. Stimulation with insulin and IGF-I in MDA-MD-435 cancer cells overexpressing E-cadherin induces a decrease of bisecting GlcNAc N-glycans that was accompanied with alterations on E-cadherin cellular localization. Concomitantly, IR/IGF-IR signaling activation induced a mesenchymal-like phenotype of cancer cells together with an increased tumor cell invasion capability. Altogether, these results demonstrate an interplay between E-cadherin and IR/IGF-IR signaling as major networking players in the regulation of bisecting N-glycans expression, with important effects in the modulation of epithelial characteristics and tumor cell invasion. Here we provide new insights into the role that Insulin/IGF-I signaling play during cancer progression through glycosylation modifications. PMID:24282611

Bisected, complex N-glycans and galectins in mouse mammary tumor progression and human breast cancer

PubMed Central

Miwa, Hazuki E; Koba, Wade R; Fine, Eugene J; Giricz, Orsi; Kenny, Paraic A; Stanley, Pamela

2013-01-01

Bisected, complex N-glycans on glycoproteins are generated by the glycosyltransferase MGAT3 and cause reduced cell surface binding of galectins. Previously, we showed that MGAT3 reduces growth factor signaling and retards mammary tumor progression driven by the Polyoma middle T antigen (PyMT) expressed in mammary epithelium under the mouse mammary tumor virus (MMTV) promoter. However, the penetrance of the tumor phenotype became variable in mixed FVB/N and C57BL/6 female mice and we therefore investigated a congenic C57BL/6 Mgat3−/−/MMTV-PyMT model. In the absence of MGAT3, C57BL/6 Mgat3−/−/MMTV-PyMT females exhibited accelerated tumor appearance and increased tumor burden, glucose uptake in tumors and lung metastasis. Nevertheless, activation of extracellular signal-regulated kinase (ERK)1/2 or protein kinase B (AKT) was reduced in ∼20-week C57BL/6 MMTV-PyMT tumors lacking MGAT3. Activation of focal adhesion kinase (FAK), protein tyrosine kinase Src, and p38 mitogen-activated protein kinase were similar to that of controls. All the eight mouse galectin genes were expressed in mammary tumors and tumor epithelial cells (TECs), but galectin-2 and -12 were not detected by western analysis in tumors, and galectin-7 was not detected in 60% of the TEC lines. From microarray data reported for human breast cancers, at least 10 galectin and 7 N-glycan N-acetylglucosaminyl (GlcNAc)-transferase (MGAT) genes are expressed in tumor tissue, and expression often varies significantly between different breast cancer subtypes. Thus, in summary, while MGAT3 and bisected complex N-glycans retard mouse mammary tumor progression, genetic background may modify this effect; identification of key galectins that promote mammary tumor progression in mice is not straightforward because all the eight galectin genes are expressed; and high levels of MGAT3, galectin-4, -8, -10, -13 and -14 transcripts correlate with better relapse-free survival in human breast cancer. PMID:24037315

Magical ideation modulates spatial behavior.

PubMed

Mohr, Christine; Bracha, H Stefan; Brugger, Peter

2003-01-01

Previous research has found that animals as well as persons with psychotic disorders preferentially orient away from the cerebral hemisphere with the more active dopamine system. This study investigated the modulation of spatial behavior by a mode of thinking reminiscent of the positive symptoms of psychosis. In a non-treatment-seeking sample of healthy volunteers (20 women and 16 men), the authors assessed the lateral biases in turning and veering behavior and in line bisection as a function of their magical ideation, that is, a mild form of schizotypy. Across tasks, pronounced magical ideation was associated with reduced right-sided orientation preferences. This finding suggests a relative hyperdopaminergia of the right hemisphere as the biological basis of magical ideation.

Mechanics of wheel-soil interaction

NASA Technical Reports Server (NTRS)

Houland, H. J.

1973-01-01

An approximate theory for wheel-soil interaction is presented which forms the basis for a practical solution to the problem. It is shown that two fundamental observations render the problem determinate: (1) The line of action of the resultant of radial stresses acting at the wheel soil interface approximately bisects the wheel-soil contact angle for all values of slip. (2) A shear stress surface can be hypothesized. The influence of soil inertia forces is also evaluated. A concept of equivalent cohesion is introduced which allows a convenient experimental comparison for both cohesive and frictional soils. This theory compares favorably with previous analyses and experimental data, and shows that soil inertia forces influencing the motion of a rolling wheel can be significant.

Complete NMR assignment of a bisecting hybrid-type oligosaccharide transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase.

PubMed

Yamanoi, Takashi; Oda, Yoshiki; Katsuraya, Kaname; Inazu, Toshiyuki; Yamamoto, Kenji

2016-06-02

This study describes the complete nuclear magnetic resonance (NMR) spectral assignment of a bisecting hybrid-type oligosaccharide 1, transferred by Mucor hiemalis endo-β-N-acetylglucosaminidase (Endo-M). Through (1)H- and (13)C-NMR, DQF-COSY, HSQC, HMBC, TOCSY, and NOESY experiments, we determine the structure of the glycoside linkage formed by the Endo-M transglycosylation, i.e., the connection between GlcNAc and GlcNAc in oligosaccharide 1. Copyright © 2016 Elsevier Ltd. All rights reserved.

BRSCW Reference Set Application: Karen Abbott -University of Arkansas (2014) — EDRN Public Portal

Cancer.gov

Our earlier glycoproteomic studies have identified bisecting glycoslyation and core fucosylation changes on particular glycoproteins in endometrioid ovarian cancer tissues and plasma (Abbott et al, 2010, Proteomics). We have validated that these glycan changes occur on the same glycoproteins in serous ovarian cancer plasma using a lectin-pull down western blot assays. We would like to used pooled reference samples to develop a sensitive magnetic bead-based assay to detect these glycoproteins with bisecting and core fucosylation changes.

The Behavioral Economics of Choice and Interval Timing

PubMed Central

Jozefowiez, J.; Staddon, J. E. R.; Cerutti, D. T.

2009-01-01

We propose a simple behavioral economic model (BEM) describing how reinforcement and interval timing interact. The model assumes a Weber-law-compliant logarithmic representation of time. Associated with each represented time value are the payoffs that have been obtained for each possible response. At a given real time, the response with the highest payoff is emitted. The model accounts for a wide range of data from procedures such as simple bisection, metacognition in animals, economic effects in free-operant psychophysical procedures and paradoxical choice in double-bisection procedures. Although it assumes logarithmic time representation, it can also account for data from the time-left procedure usually cited in support of linear time representation. It encounters some difficulties in complex free-operant choice procedures, such as concurrent mixed fixed-interval schedules as well as some of the data on double bisection, that may involve additional processes. Overall, BEM provides a theoretical framework for understanding how reinforcement and interval timing work together to determine choice between temporally differentiated reinforcers. PMID:19618985

Determining a bisection bandwidth for a multi-node data communications network

DOEpatents

Faraj, Ahmad A.

2010-01-26

Methods, systems, and products are disclosed for determining a bisection bandwidth for a multi-node data communications network that include: partitioning nodes in the network into a first sub-network and a second sub-network in dependence upon a topology of the network; sending, by each node in the first sub-network to a destination node in the second sub-network, a first message having a predetermined message size; receiving, by each node in the first sub-network from a source node in the second sub-network, a second message; measuring, by each node in the first sub-network, the elapsed communications time between the sending of the first message and the receiving of the second message; selecting the longest elapsed communications time; and calculating the bisection bandwidth for the network in dependence upon the number of the nodes in the first sub-network, the predetermined message size of the first test message, and the longest elapsed communications time.

Subjective time in near and far representational space.

PubMed

Zäch, Peter; Brugger, Peter

2008-03-01

We set out to measure healthy subjects' estimates of temporal duration during the imagination of left and right sides of an object located in either near or far representational space. Duration estimates during the observation of small-scale scenes are shorter than those during the observation of the same scenes presented in a larger scale. It is not known whether a similar space-time relationship also exists for objects merely imagined and whether subjective time varies with a forced focus on either the left or the right side of a mental image. Eyes closed, 40 healthy, right-handed subjects (20 women) had to imagine a standard Swiss railway clock either at a distance of 30 cm or 6 m. They were required to focus on the imagined movement of the second hand and provide estimates of elapsed durations of 15 and 30 seconds. Separate estimates for the left and right side of the clockface were obtained. The magnitude of implicit line bisection error was assessed in a separate task. Irrespective of side of the clockface, duration estimates were shorter for the clockface imagined in far space than for the one imagined immediately in front of the inner eye. For men, but not women, duration judgments (left relative to right side of the clockface) correlated with relative lengths of left and right line segments in the bisection task. Subjective time seems to run faster during the inspection of a small-size compared with a larger-size mental image. This finding underlines the equivalence of the laws that guide both exploration and representation of space. Together with the observed correlation between spatial and temporal measures of lateral asymmetries, the result also illustrates the conceptual similarities in the processing of space and time. The normative data presented here may be useful for clinical applications of the paradigm in patients with hemispatial neglect or a distorted perception of time.

Perception while watching movies: Effects of physical screen size and scene type.

PubMed

Troscianko, Tom; Meese, Timothy S; Hinde, Stephen

2012-01-01

Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that "bigger is better." However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image size (C. A. Burbeck, 1987), we wondered whether object size itself might be an important factor. To test this, we needed a task that would tap into the subjective experiences of participants watching a movie on different-sized displays with the same retinal subtense. Our participants used a line bisection task to self-report their level of "presence" (i.e., their involvement with the movie) at several target locations that were probed in a 45-min section of the movie "The Good, The Bad, and The Ugly." Measures of pupil dilation and reaction time to the probes were also obtained. In Experiment 1, we found that subjective ratings of presence increased with physical screen size, supporting our hypothesis. Face scenes also produced higher presence scores than landscape scenes for both screen sizes. In Experiment 2, reaction time and pupil dilation results showed the same trends as the presence ratings and pupil dilation correlated with presence ratings, providing some validation of the method. Overall, the results suggest that real-time measures of subjective presence might be a valuable tool for measuring audience experience for different types of (i) display and (ii) audiovisual material.

The Spider Center Wide File System; From Concept to Reality

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

Shipman, Galen M; Dillow, David A; Oral, H Sarp

2009-01-01

The Leadership Computing Facility (LCF) at Oak Ridge National Laboratory (ORNL) has a diverse portfolio of computational resources ranging from a petascale XT4/XT5 simulation system (Jaguar) to numerous other systems supporting development, visualization, and data analytics. In order to support vastly different I/O needs of these systems Spider, a Lustre-based center wide file system was designed and deployed to provide over 240 GB/s of aggregate throughput with over 10 Petabytes of formatted capacity. A multi-stage InfiniBand network, dubbed as Scalable I/O Network (SION), with over 889 GB/s of bisectional bandwidth was deployed as part of Spider to provide connectivity tomore » our simulation, development, visualization, and other platforms. To our knowledge, while writing this paper, Spider is the largest and fastest POSIX-compliant parallel file system in production. This paper will detail the overall architecture of the Spider system, challenges in deploying and initial testings of a file system of this scale, and novel solutions to these challenges which offer key insights into file system design in the future.« less

Aspects of Collisionless Magnetic Reconnection in Asymmetric Systems

NASA Technical Reports Server (NTRS)

Hesse, Michael; Aunai, Nicolas; Zenitani, Seiji; Kuznetsova, Masha; Birn, Joachim

2013-01-01

Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: The direction of the reconnection line in configurations with nonvanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.

Aspects of Collisionless Magnetic Reconnection in Asymmetric Systems

NASA Technical Reports Server (NTRS)

Hesse, Michael; Aunai, Nicolas; Zeitani, Seiji; Kuznetsova, Masha; Birn, Joachim

2013-01-01

Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with non-vanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement for particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.

Aspects of collisionless magnetic reconnection in asymmetric systems

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

Hesse, Michael; Aunai, Nicolas; Kuznetsova, Masha

2013-06-15

Asymmetric reconnection is being investigated by means of particle-in-cell simulations. The research has two foci: the direction of the reconnection line in configurations with nonvanishing magnetic fields; and the question why reconnection can be faster if a guide field is added to an otherwise unchanged asymmetric configuration. We find that reconnection prefers a direction, which maximizes the available magnetic energy, and show that this direction coincides with the bisection of the angle between the asymptotic magnetic fields. Regarding the difference in reconnection rates between planar and guide field models, we demonstrate that a guide field can provide essential confinement formore » particles in the reconnection region, which the weaker magnetic field in one of the inflow directions cannot necessarily provide.« less

Keeping your distance: attentional withdrawal in individuals who show physiological signs of social discomfort.

PubMed

Szpak, Ancret; Loetscher, Tobias; Churches, Owen; Thomas, Nicole A; Spence, Charles J; Nicholls, Michael E R

2015-04-01

Being in close social proximity to a stranger is generally perceived to be an uncomfortable experience, which most people seek to avoid. In circumstances where crowding is unavoidable, however, people may seek to withdraw their attention from the other person. This study examined whether social discomfort, as indexed by electrodermal activity, is related to a withdrawal of attention in 28 (m=8, f=20) university students. Students performed a radial line bisection task while alone or together with a stranger facing them. Physiological arousal was indexed by a wrist monitor, which recorded electrodermal activity. Correlational analyses showed that individuals who displayed physiological discomfort when together showed a withdrawal of the perceived midpoint of the line towards them (and away from the stranger). Conversely, individuals who showed no discomfort exhibited an expansion of the perceived midpoint away from them. We propose that participants shift their attention away from the stranger to increase interpersonal distance and reduce anxiety/arousal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Earth Observations taken by the Expedition 15 Crew

NASA Image and Video Library

2007-05-13

ISS015-E-07934 (13 May 2007) --- Mazatlan, Mexico is featured in this image photographed by an Expedition 15 crewmember on the International Space Station. Mazatlan is Mexico's largest port, situated on one of the best estuaries on Mexico's Pacific coast, illustrated well in this image. Docks and naval yards line the north side of the estuary. The city itself appears as a series of light-toned city blocks covering the center of the image. Mazatlan (population of 352,000 in 2005) is growing northward from the downtown peninsula, with tourist beaches backed by hotels, and a marina and golf courses just beyond. No city growth yet appears on the south side the estuary where farm lands can be seen. The famous Faro Lighthouse occupies the top of a steep island--now connected by a bridge to the mainland--at the mouth of the estuary (top center). The Faro Lighthouse is the second tallest in the world behind Gibraltar's. The wide, straight, almost vertical line of the railroad appears to bisect the picture. This image shows sea features well, primarily ocean swells coming in from the southwest, which appear as a series of parallel lines covering the entire sea surface in this view. An oil slick offshore of the tourist beaches appears as a dark line along the left side of the image.

Graph Theoretical Analysis Reveals: Women's Brains Are Better Connected than Men's.

PubMed

Szalkai, Balázs; Varga, Bálint; Grolmusz, Vince

2015-01-01

Deep graph-theoretic ideas in the context with the graph of the World Wide Web led to the definition of Google's PageRank and the subsequent rise of the most popular search engine to date. Brain graphs, or connectomes, are being widely explored today. We believe that non-trivial graph theoretic concepts, similarly as it happened in the case of the World Wide Web, will lead to discoveries enlightening the structural and also the functional details of the animal and human brains. When scientists examine large networks of tens or hundreds of millions of vertices, only fast algorithms can be applied because of the size constraints. In the case of diffusion MRI-based structural human brain imaging, the effective vertex number of the connectomes, or brain graphs derived from the data is on the scale of several hundred today. That size facilitates applying strict mathematical graph algorithms even for some hard-to-compute (or NP-hard) quantities like vertex cover or balanced minimum cut. In the present work we have examined brain graphs, computed from the data of the Human Connectome Project, recorded from male and female subjects between ages 22 and 35. Significant differences were found between the male and female structural brain graphs: we show that the average female connectome has more edges, is a better expander graph, has larger minimal bisection width, and has more spanning trees than the average male connectome. Since the average female brain weighs less than the brain of males, these properties show that the female brain has better graph theoretical properties, in a sense, than the brain of males. It is known that the female brain has a smaller gray matter/white matter ratio than males, that is, a larger white matter/gray matter ratio than the brain of males; this observation is in line with our findings concerning the number of edges, since the white matter consists of myelinated axons, which, in turn, roughly correspond to the connections in the brain graph. We have also found that the minimum bisection width, normalized with the edge number, is also significantly larger in the right and the left hemispheres in females: therefore, the differing bisection widths are independent from the difference in the number of edges.

Graph Theoretical Analysis Reveals: Women’s Brains Are Better Connected than Men’s

PubMed Central

Szalkai, Balázs; Varga, Bálint; Grolmusz, Vince

2015-01-01

Deep graph-theoretic ideas in the context with the graph of the World Wide Web led to the definition of Google’s PageRank and the subsequent rise of the most popular search engine to date. Brain graphs, or connectomes, are being widely explored today. We believe that non-trivial graph theoretic concepts, similarly as it happened in the case of the World Wide Web, will lead to discoveries enlightening the structural and also the functional details of the animal and human brains. When scientists examine large networks of tens or hundreds of millions of vertices, only fast algorithms can be applied because of the size constraints. In the case of diffusion MRI-based structural human brain imaging, the effective vertex number of the connectomes, or brain graphs derived from the data is on the scale of several hundred today. That size facilitates applying strict mathematical graph algorithms even for some hard-to-compute (or NP-hard) quantities like vertex cover or balanced minimum cut. In the present work we have examined brain graphs, computed from the data of the Human Connectome Project, recorded from male and female subjects between ages 22 and 35. Significant differences were found between the male and female structural brain graphs: we show that the average female connectome has more edges, is a better expander graph, has larger minimal bisection width, and has more spanning trees than the average male connectome. Since the average female brain weighs less than the brain of males, these properties show that the female brain has better graph theoretical properties, in a sense, than the brain of males. It is known that the female brain has a smaller gray matter/white matter ratio than males, that is, a larger white matter/gray matter ratio than the brain of males; this observation is in line with our findings concerning the number of edges, since the white matter consists of myelinated axons, which, in turn, roughly correspond to the connections in the brain graph. We have also found that the minimum bisection width, normalized with the edge number, is also significantly larger in the right and the left hemispheres in females: therefore, the differing bisection widths are independent from the difference in the number of edges. PMID:26132764

Analyzing milestoning networks for molecular kinetics: definitions, algorithms, and examples.

PubMed

Viswanath, Shruthi; Kreuzer, Steven M; Cardenas, Alfredo E; Elber, Ron

2013-11-07

Network representations are becoming increasingly popular for analyzing kinetic data from techniques like Milestoning, Markov State Models, and Transition Path Theory. Mapping continuous phase space trajectories into a relatively small number of discrete states helps in visualization of the data and in dissecting complex dynamics to concrete mechanisms. However, not only are molecular networks derived from molecular dynamics simulations growing in number, they are also getting increasingly complex, owing partly to the growth in computer power that allows us to generate longer and better converged trajectories. The increased complexity of the networks makes simple interpretation and qualitative insight of the molecular systems more difficult to achieve. In this paper, we focus on various network representations of kinetic data and algorithms to identify important edges and pathways in these networks. The kinetic data can be local and partial (such as the value of rate coefficients between states) or an exact solution to kinetic equations for the entire system (such as the stationary flux between vertices). In particular, we focus on the Milestoning method that provides fluxes as the main output. We proposed Global Maximum Weight Pathways as a useful tool for analyzing molecular mechanism in Milestoning networks. A closely related definition was made in the context of Transition Path Theory. We consider three algorithms to find Global Maximum Weight Pathways: Recursive Dijkstra's, Edge-Elimination, and Edge-List Bisection. The asymptotic efficiency of the algorithms is analyzed and numerical tests on finite networks show that Edge-List Bisection and Recursive Dijkstra's algorithms are most efficient for sparse and dense networks, respectively. Pathways are illustrated for two examples: helix unfolding and membrane permeation. Finally, we illustrate that networks based on local kinetic information can lead to incorrect interpretation of molecular mechanisms.

Enhancing the visuo-spatial aptitude of students

NASA Astrophysics Data System (ADS)

Lord, Thomas R.

Research to date has not been able to agree whether visuo-spatial ability can be influenced through practice. Many have concluded that spatial awareness is an innate phenomena and cannot be learned. Others contend that an individual's visuo-spatial potentials are acquired through interactions with the environment. Many of these theorists believe that spatial thinking can be developed through interactive exercises devised to encourage mental image formation and manipulation. To help alleviate the confusion surrounding this question the following study was undertaken. Eighty-four college undergraduates were randomly placed into control and experimental sections. Student records were examined to assure that the groups did not differ significantly in their verbal or math proficiency and pertinent pretests were given to ascertain spatial levels. The groups were also similar on their male and female ratios. During the semester the experimental section was treated to a 30-minute interaction each week. These sessions involved spatial exercises that required the participants to mentally bisect three-dimensional geometric figures and to envision the shape of the two-dimensional surface formed by the bisection. The subjects drew their mental image of this surface on a sheet of paper. Fourteen weeks later both groups were post tested with a second comparable version of the pretest. Statistical t tests were performed on the group means to see if significant differences developed between the sections. The results indicate that statistical improvement in visuo-spatial cognition did occur for the experimental group in spatial visualization, and spatial orientation. This finding suggests that the weekly intervention sessions had a positive effect on the students' visuo-spatial awareness. These results, therefore, tend to support those researchers that claim visuo-spatial aptitude can be enhanced through teaching.

A Constant-Field Interrupted Resonance System for Percutaneous Electromagnetic Measurement of Blood Flow

PubMed Central

Kolin, Alexander; Steele, James R.; Imai, James S.; Macalpin, Rex N.

1974-01-01

A combination of deformable flow probes of negligible lateral dimensions with an electronic circuit capable of providing a prolonged plateau of dB/dt = 0 and of sampling the flow signal at the end of this interval permits electromagnetic measurement of blood flow with a reliable zero base line secured by switching off the magnet. An extracorporeal magnet provides the magnetic field. The flow transducer is introduced into the vascular system percutaneously through a standard angiographic catheter by conventional technique. The idea of the current generator can be described as “principle of interrupted resonance.” The current wave form can be described as a sequence of disconnected bisected sine waves joined at the apices by horizontal current plateaus where di/dt is strictly zero. Images PMID:4275395

What Does It Take to Search Organized? The Cognitive Correlates of Search Organization During Cancellation After Stroke.

PubMed

Ten Brink, Antonia F; Visser-Meily, Johanna M A; Nijboer, Tanja C W

2018-05-01

Stroke could lead to deficits in organization of visual search. Cancellation tests are frequently used in standard neuropsychological assessment and appear suitable to measure search organization. The current aim was to evaluate which cognitive functions are associated with cancellation organization measures after stroke. Stroke patients admitted to inpatient rehabilitation were included in this retrospective study. We performed exploratory factor analyses to explore cognitive domains. A digital shape cancellation test (SC) was administered, and measures of search organization (intersections rate and best r) were computed. The following cognitive functions were measured by neuropsychological testing: neglect (SC, line bisection; LB, Catherine Bergego Scale; CBS, and Balloons Test), visuospatial perception and construction (Rey Complex Figure Test, RCFT), psychomotor speed (Trail Making Test; TMT-A), executive functioning/working memory (TMT-B), spatial planning (Tower Test), rule learning (Brixton Test), short-term auditory memory (Digit Span Forward; DSF), and verbal working memory (Digit Span Backward; DSB). In total, 439 stroke patients were included in our analyses. Four clusters were separated: "Executive functioning" (TMT-A, TMT-B, Brixton Test, and Tower Test), "Verbal memory" (DSF and DSB), "Search organization" (intersections rate and best r), and "Neglect" (CBS, RCFT copy, Balloons Test, SC, and LB). Search organization during cancellation, as measured with intersections rate and best r, seems a distinct cognitive construct compared to existing cognitive domains that are tested during neuropsychological assessment. Administering cancellation tests and analyzing measures of search organization could provide useful additional insights into the visuospatial processes of stroke patients. (JINS, 2018, 24, 424-436).

Perception while watching movies: Effects of physical screen size and scene type

PubMed Central

Troscianko, Tom; Meese, Timothy S.; Hinde, Stephen

2012-01-01

Over the last decade, television screens and display monitors have increased in size considerably, but has this improved our televisual experience? Our working hypothesis was that the audiences adopt a general strategy that “bigger is better.” However, as our visual perceptions do not tap directly into basic retinal image properties such as retinal image size (C. A. Burbeck, 1987), we wondered whether object size itself might be an important factor. To test this, we needed a task that would tap into the subjective experiences of participants watching a movie on different-sized displays with the same retinal subtense. Our participants used a line bisection task to self-report their level of “presence” (i.e., their involvement with the movie) at several target locations that were probed in a 45-min section of the movie “The Good, The Bad, and The Ugly.” Measures of pupil dilation and reaction time to the probes were also obtained. In Experiment 1, we found that subjective ratings of presence increased with physical screen size, supporting our hypothesis. Face scenes also produced higher presence scores than landscape scenes for both screen sizes. In Experiment 2, reaction time and pupil dilation results showed the same trends as the presence ratings and pupil dilation correlated with presence ratings, providing some validation of the method. Overall, the results suggest that real-time measures of subjective presence might be a valuable tool for measuring audience experience for different types of (i) display and (ii) audiovisual material. PMID:23145293

Music-induced changes in functional cerebral asymmetries.

PubMed

Hausmann, Markus; Hodgetts, Sophie; Eerola, Tuomas

2016-04-01

After decades of research, it remains unclear whether emotion lateralization occurs because one hemisphere is dominant for processing the emotional content of the stimuli, or whether emotional stimuli activate lateralised networks associated with the subjective emotional experience. By using emotion-induction procedures, we investigated the effect of listening to happy and sad music on three well-established lateralization tasks. In a prestudy, Mozart's piano sonata (K. 448) and Beethoven's Moonlight Sonata were rated as the most happy and sad excerpts, respectively. Participants listened to either one emotional excerpt, or sat in silence before completing an emotional chimeric faces task (Experiment 1), visual line bisection task (Experiment 2) and a dichotic listening task (Experiment 3 and 4). Listening to happy music resulted in a reduced right hemispheric bias in facial emotion recognition (Experiment 1) and visuospatial attention (Experiment 2) and increased left hemispheric bias in language lateralization (Experiments 3 and 4). Although Experiments 1-3 revealed an increased positive emotional state after listening to happy music, mediation analyses revealed that the effect on hemispheric asymmetries was not mediated by music-induced emotional changes. The direct effect of music listening on lateralization was investigated in Experiment 4 in which tempo of the happy excerpt was manipulated by controlling for other acoustic features. However, the results of Experiment 4 made it rather unlikely that tempo is the critical cue accounting for the effects. We conclude that listening to music can affect functional cerebral asymmetries in well-established emotional and cognitive laterality tasks, independent of music-induced changes in the emotion state. Copyright © 2016 Elsevier Inc. All rights reserved.

Genetic Algorithm for Optimization: Preprocessing with n Dimensional Bisection and Error Estimation

NASA Technical Reports Server (NTRS)

Sen, S. K.; Shaykhian, Gholam Ali

2006-01-01

A knowledge of the appropriate values of the parameters of a genetic algorithm (GA) such as the population size, the shrunk search space containing the solution, crossover and mutation probabilities is not available a priori for a general optimization problem. Recommended here is a polynomial-time preprocessing scheme that includes an n-dimensional bisection and that determines the foregoing parameters before deciding upon an appropriate GA for all problems of similar nature and type. Such a preprocessing is not only fast but also enables us to get the global optimal solution and its reasonably narrow error bounds with a high degree of confidence.

Process of pigment cell specification in the sand dollar, Scaphechinus mirabilis.

PubMed

Kominami, Tetsuya; Takata, Hiromi

2002-04-01

The process of pigment cell specification in the sand dollar Scaphechinus mirabilis was examined by manipulative methods. In half embryos, which were formed by dissociating embryos at the 2-cell stage, the number of pigment cells was significantly greater than half the number of pigment cells observed in control embryos. This relative increase might have been brought about by the change in the arrangement of blastomeres surrounding the micromere progeny. To examine whether such an increase could be induced at a later stage, embryos were bisected with a glass needle. When embryos were bisected before 7 h postfertilization, the sum of pigment cells observed in a pair of embryo fragments was greater than that in control embryos. This relative increase was not seen when embryos were bisected after 7 h postfertilization. From the size of blastomeres, it became clear that the 9th cleavage was completed by 7 h postfertilization. Aphidicolin treatment revealed that 10-15 pigment founder cells were formed. The results obtained suggest that the pigment founder cells were specified through direct cell contact with micromere progeny after the 9th cleavage, and that most of the founder cells had divided three times before they differentiated into pigment cells.

The right side? Under time pressure, approach motivation leads to right-oriented bias.

PubMed

Roskes, Marieke; Sligte, Daniel; Shalvi, Shaul; De Dreu, Carsten K W

2011-11-01

Approach motivation, a focus on achieving positive outcomes, is related to relative left-hemispheric brain activation, which translates to a variety of right-oriented behavioral biases. In two studies, we found that approach-motivated individuals display a right-oriented bias, but only when they are forced to act quickly. In a task in which they had to divide lines into two equal parts, approach-motivated individuals bisected the line at a point farther to the right than avoidance-motivated individuals did, but only when they worked under high time pressure. In our analysis of all Fédération Internationale de Football Association (FIFA) World Cup penalty shoot-outs, we found that goalkeepers were two times more likely to dive to the right than to the left when their team was behind, a situation that we conjecture induces approach motivation. Because penalty takers shot toward the two sides of the goal equally often, the goalkeepers' right-oriented bias was dysfunctional, allowing more goals to be scored. Directional biases may facilitate group coordination but prove maladaptive in individual settings and interpersonal competition.

Tourism impacts of Three Mile Island and other adverse events: Implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

NASA Astrophysics Data System (ADS)

Himmelberger, Jeffery J.; Baughman, Mike; Ogneva-Himmelberger, Yelena A.

1995-11-01

Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportatin corridors (highway or rail). As part of one such county's repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have beem revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings.

Glycosylation of random IgG distinguishes seropositive and seronegative rheumatoid arthritis.

PubMed

Magorivska, I; Döncző, B; Dumych, T; Karmash, A; Boichuk, M; Hychka, K; Mihalj, M; Szabó, M; Csánky, E; Rech, J; Guttman, A; Vari, S G; Bilyy, R

2018-05-01

The N-glycosylation of human immunoglobulins, especially IgGs, plays a critical role in determining affinity of IgGs towards their effector (pro- and anti-inflammatory) receptors. However, it is still not clear whether altered glycosylation is involved in only antibody-dependent disorders like seropositive rheumatoid arthritis (RA) or also in pathologies with similar clinical manifestations, but no specific autoantibodies like seronegative RA. The clarification of that uncertainty was the aim of the current study. Another study aim was the detection of specific glycan forms responsible for altered exposure of native glycoepitopes. We studied sera from seropositive RA (n = 15) and seronegative RA (n = 12) patients for exposure of glycans in native IgG molecules, followed by determination of specific glycans by capillary electrophoresis with laser-induced fluorescent detection (CE-LIF). Aged-matched groups of normal healthy donors (NHD) and samples of intravenous immunoglobulin IgG preparations (IVIG) served as controls. There was significantly stronger binding of Lens culinaris agglutinin (LCA) and Aleuria aurantia lectin (AAL) lectins towards IgG from seropositive RA compared to seronegative RA or NHD. CE-LIF analysis revealed statistically significant increases in bisecting glycans FA2BG2 (p = .006) and FABG2S1 (p = .005) seropositive RA, accompanied by decrease of bisecting monogalactosylated glycan FA2(6)G1 (p = .074) and non-bisecting monosialylated glycan FA2(3)G1S1 (p = .055). The results suggest that seropositive RA is distinct from seronegative RA in terms of IgG glycan moieties, attributable to specific immunoglobulin molecules present in seropositive disease. These glycans were determined to be bisecting GlcNAc-bearing forms FA2BG2 and FABG2S1, and their appearance increased the availability of LCA and AAL lectin-binding sites in native IgG glycoepitopes.

Is the effectiveness of patellofemoral bracing modified by patellofemoral alignment and trochlear morphology?

PubMed

Zhang, Xi; Eyles, Jillian P; Makovey, Joanna; Williams, Matthew J; Hunter, David J

2017-04-21

This study was performed to determine if the effectiveness of patellofemoral bracing as a treatment for patellofemoral osteoarthritis is influenced by patellofemoral joint alignment and trochlear morphology. We hypothesized that those with more extreme patellar malalignment would benefit more from bracing. Thirty-eight patients who had received bracing as part of a comprehensive treatment plan for patellofemoral osteoarthritis were selected for this study. Ten measures of patellar alignment were taken from X-rays. These alignment measures were divided into percentile groups (tertiles) for contingency table analysis. Treatment outcome was measured by Western Ontario and Macmasters Universities Osteoarthritis Index (WOMAC) scores and these were dichotomised into two groups according to "Improved" or "Not Improved" according to the minimum clinically important difference (MCID). Spearman's rho test was performed for continuous variables and Fisher's exact test was performed for correlation between tertile groups and MCID categories. Thirty-eight patients (9 male and 29 female) between the ages of 51 to 89 were included in this study. WOMAC scores ranged from -25 to 41.67, with a mean change of -3.97, 31.6, 44.7 and 31.6% of patients falling into the "Improved" group for Global, Pain and Function scores respectively. We found a non-significant trend shown (p = 0.058, correlation coefficient 0.31) between bisect offset and change in WOMAC global, indicating a trend for higher change in WOMAC scores with increasing bisect offset. Statistically significant correlations were found between mean MCID categories for the WOMAC global and function groups when analysed against percentile groups for bisect offset (p < 0.01) and patellar subluxation distance (p < 0.05), indicating those in higher percentile groups were more likely not to improve after six months. Higher bisect offset and patellar subluxation distance measures were associated with poorer outcomes. However, due to the limited sample size, more studies are required to fully examine this relationship.

Seeing the hand while reaching speeds up on-line responses to a sudden change in target position

PubMed Central

Reichenbach, Alexandra; Thielscher, Axel; Peer, Angelika; Bülthoff, Heinrich H; Bresciani, Jean-Pierre

2009-01-01

Goal-directed movements are executed under the permanent supervision of the central nervous system, which continuously processes sensory afferents and triggers on-line corrections if movement accuracy seems to be compromised. For arm reaching movements, visual information about the hand plays an important role in this supervision, notably improving reaching accuracy. Here, we tested whether visual feedback of the hand affects the latency of on-line responses to an external perturbation when reaching for a visual target. Two types of perturbation were used: visual perturbation consisted in changing the spatial location of the target and kinesthetic perturbation in applying a force step to the reaching arm. For both types of perturbation, the hand trajectory and the electromyographic (EMG) activity of shoulder muscles were analysed to assess whether visual feedback of the hand speeds up on-line corrections. Without visual feedback of the hand, on-line responses to visual perturbation exhibited the longest latency. This latency was reduced by about 10% when visual feedback of the hand was provided. On the other hand, the latency of on-line responses to kinesthetic perturbation was independent of the availability of visual feedback of the hand. In a control experiment, we tested the effect of visual feedback of the hand on visual and kinesthetic two-choice reaction times – for which coordinate transformation is not critical. Two-choice reaction times were never facilitated by visual feedback of the hand. Taken together, our results suggest that visual feedback of the hand speeds up on-line corrections when the position of the visual target with respect to the body must be re-computed during movement execution. This facilitation probably results from the possibility to map hand- and target-related information in a common visual reference frame. PMID:19675067

A virtual reality test battery for assessment and screening of spatial neglect.

PubMed

Fordell, H; Bodin, K; Bucht, G; Malm, J

2011-03-01

There is a need for improved screening methods for spatial neglect. To construct a VR-test battery and evaluate its accuracy and usability in patients with acute stroke. VR-DiSTRO consists of a standard desktop computer, a CRT monitor and eye shutter stereoscopic glasses, a force feedback interface, and software, developed to create an interactive and immersive 3D experience. VR-tests were developed and validated to the conventional Star Cancellation test, Line bisection, Baking Tray Task (BTT), and Visual Extinction test. A construct validation to The Rivermead Behavioral Inattention Test, used as criterion of visuospatial neglect, was made. Usability was assessed according to ISO 9241-11. Thirty-one patients with stroke were included, 9/31 patients had neglect. The sensitivity was 100% and the specificity 82% for the VR-DiSTRO to correctly identify neglect. VR-BTT and VR-Extinction had the highest correlation (r² = 0.64 and 0.78), as well as high sensitivity and specificity. The kappa values describing the agreement between traditional neglect tests and the corresponding virtual reality test were between 0.47-0.85. Usability was assessed by a questionnaire; 77% reported that the VR-DiSTRO was 'easy' to use. Eighty-eight percent reported that they felt 'focused', 'pleased' or 'alert'. No patient had adverse symptoms. The test session took 15 min. The VR-DiSTRO quickly and with a high accuracy identified visuospatial neglect in patients with stroke in this construct validation. The usability among elderly patients with stroke was high. This VR-test battery has the potential to become an important screening instrument for neglect and a valuable adjunct to the neuropsychological assessment. © 2010 John Wiley & Sons A/S.

Continuous theta-burst stimulation may improve visuospatial neglect via modulating the attention network: a randomized controlled study.

PubMed

Fu, Wei; Cao, Lei; Zhang, Yanming; Huo, Su; Du, JuBao; Zhu, Lin; Song, Weiqun

2017-05-01

Visuospatial neglect (VSN) is devastating and common after stroke, and is thought to involve functional disturbance of the attention network. Non-invasive theta-burst stimulation (TBS) may help restore the normal function of attention network, therefore facilitating recovery from VSN. This study investigated the effects of continuous TBS on resting-state functional connectivity (RSFC) in the attention network, and behavioral performances of patients with VSN after stroke. Twelve patients were randomly assigned to receive 10-day cTBS of the left posterior parietal cortex delivered at 80% (the cTBS group), or 40% (the active control group) of the resting motor threshold. Both groups received daily visual scanning training and motor function treatment. Resting-state functional MRI (fMRI) and behavioral tests including line bisection test and star cancelation test were conducted at baseline and after the treatment. At baseline, the two groups showed comparable results in the resting-state fMRI experiments and behavioral tests. After treatment, the cTBS group showed lower functional connectivity between right temporoparietal junction (TPJ) and right anterior insula, and between right superior temporal sulcus and right anterior insula, as compared with the active control group; both groups showed improvement in the behavioral tests, with the cTBS group showing larger changes from baseline than the active control group. cTBS of the left posterior parietal cortex in patients with VSN may induce changes in inter-regional RSFC in the right ventral attention network. These changes may be associated with improved recovery of behavioral deficits after behavioral training. The TPJ and superior temporal sulcus may play crucial roles in recovery from VSN.

Full-Mouth Intraoral Radiographic Survey in Rabbits.

PubMed

Regalado, Adriana; Legendre, Loïc

2017-09-01

Dental pathologies are highly prevalent in pet rabbit populations, making oral radiography an essential tool in the evaluation of lagomorph dentitions. The unique anatomy of the rabbit's mouth limits the examination of the conscious animal to the rostral portion of it's mouth. In addition, the oral examination of an aradicular hypsodont tooth is restricted to the short coronal fraction of its crown. Erstwhile images obtained by the extraoral technique were once considered the most practical and informative tool in rabbit dentistry; however, limited visualization of the key structures of individual teeth became the major drawback of this technique. As new imaging technologies are becoming widely available and affordable for veterinarians, intraoral radiography offers the ability to prevent, diagnose, and treat oral pathologies in lagomorphs. This article describes a step-by-step procedure to obtain a full-mouth radiographic survey in rabbits. For this technique, a standard dental X-ray generator and intraoral storage phosphor plates are used while applying the bisecting angle technique. Among the advantages of this technique are detailed visualization of internal and external dental structures, identification of early lesions, and detection of occult pathologies. Furthermore, intraoral images offer superior resolution and higher diagnostic quality with minimal radiation exposure, making this method safer for the veterinarian, staff members, and their patients.

Individual Differences in the Flexibility of Peripersonal Space.

PubMed

Hunley, Samuel B; Marker, Arwen M; Lourenco, Stella F

2017-01-01

The current study investigated individual differences in the flexibility of peripersonal space (i.e., representational space near the body), specifically in relation to trait claustrophobic fear (i.e., fear of suffocating or being physically restricted). Participants completed a line bisection task with either a laser pointer (Laser condition), allowing for a baseline measure of the size of one's peripersonal space, or a stick (Stick condition), which produces expansion of one's peripersonal space. Our results revealed that individuals high in claustrophobic fear had larger peripersonal spaces than those lower in claustrophobic fear, replicating previous research. We also found that, whereas individuals low in claustrophobic fear demonstrated the expected expansion of peripersonal space in the Stick condition, individuals high in claustrophobic fear showed less expansion, suggesting decreased flexibility. We discuss these findings in relation to the defensive function of peripersonal space and reduced attentional flexibility associated with trait anxieties.

Human strength simulations for one and two-handed tasks in zero gravity

NASA Technical Reports Server (NTRS)

1972-01-01

A description is given of a three dimensional hand force capability model for the seated operator and a biomechanical model for analysis of symmetric sagittal plane activities. The models are used to simulate and study human strengths for one and two handed tasks in zero gravity. Specific conditions considered include: (1) one hand active, (2) both hands active but with different force directions on each, (3) body bracing situations provided by portable foot restraint when standing and lap belt when seated, (4) static or slow movement tasks with maximum length of 4 seconds and a minimum rest of 5 minutes between exertions, and (5) wide range of hand positions relative to either the feet or bisection of a line connecting the hip centers. Simulations were also made for shirt sleeved individuals and for the male population strengths with anthropometry matching that of astronauts.

Application of a 1.48-microm diode laser for bisecting oocytes into two identical hemizonae for the hemizona assay.

PubMed

Edenfeld, J; Schöpper, B; Sturm, R; Diedrich, K; Al-Hasani, S

2002-04-01

Laser systems are very promising new technical tools in assisted reproduction. It was investigated if laser radiation can replace the mechanical cutting procedure via micromanipulator in the hemizona assay (HZA), a commonly used bioassay to determine the sperm-zona pellucida binding capacity. An oocyte was bisected precisely into two identical hemizonae with approximately 20 laser pulses (pulse length 30 msec) using a 1.48-microm diode laser. Compared with the conventional method using microscalpels for zona bisection, laser treated hemizonae showed equivalent sperm-binding and within the two groups there was no detectable difference between matching hemizonae in their capacity for tight sperm-binding. To evaluate whether laser radiation affects the outcome of the HZA when effects of certain substances are investigated, the spermatozoa were preincubated with human follicular fluid (hFF), which inhibits the binding of spermatozoa to zona pellucida in vitro. Supplementation with follicular fluid exerted an inhibitory effect in both groups. The hemizona index (HZI) showed no statistical differences between the two methods. Therefore, the 1.48-microm diode laser is a suitable new instrument for generating equally sized hemizonae. There is no use for holding pipettes and microscalpels, on the contrary, for performing the HZA the laser is a precise, very quick and easy to use new working tool.

Further tests of the Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model in a temporal bisection task.

PubMed

Machado, Armando; Arantes, Joana

2006-06-01

To contrast two models of timing, Scalar Expectancy Theory (SET) and Learning to Time (LeT), pigeons were exposed to a double temporal bisection procedure. On half of the trials, they learned to choose a red key after a 1s signal and a green key after a 4s signal; on the other half of the trials, they learned to choose a blue key after a 4-s signal and a yellow key after a 16-s signal. This was Phase A of an ABA design. On Phase B, the pigeons were divided into two groups and exposed to a new bisection task in which the signals ranged from 1 to 16s and the choice keys were blue and green. One group was reinforced for choosing blue after 1-s signals and green after 16-s signals and the other group was reinforced for the opposite mapping (green after 1-s signals and blue after 16-s signals). Whereas SET predicted no differences between the groups, LeT predicted that the former group would learn the new discrimination faster than the latter group. The results were consistent with LeT. Finally, the pigeons returned to Phase A. Only LeT made specific predictions regarding the reacquisition of the four temporal discriminations. These predictions were only partly consistent with the results.

Analysis and explanation of the Thiéry-Wundt illusion.

PubMed

Day, Ross H; Kimm, Andrew C

2010-01-01

The midpoint of the axis of bisection in a triangle appears to be displaced toward the apex so that the apical extent seems to be shorter than the basal extent, an effect originally reported in 1895 by Thiéry and later in 1898 by Wundt and, therefore, referred to here as the Thiéry-Wundt illusion. Following a demonstration strongly suggesting that the illusion is yet another version of the Müller-Lyer effect in a stimulus figure with inward-directed angles, four exploratory experiments designed to throw more light on this group of illusions are reported. The first showed that the effect occurs in an open angle, between converging lines that do not meet to form an apex, between converging stepped lines, and when one of the converging lines is removed, leaving a single oblique line. The other three experiments showed that the illusion also occurs in an open semicircle and a rectangular bracket, is weakened by the addition of a complete or partial baseline to form a triangle, and weakly but reliably when the angle is minimally formed from dots marking the ends of oblique lines. On the basis of these data, Judd's version of the conventional Müller-Lyer figure, and informal but easily repeatable observations, it is concluded that the Thiéry-Wundt illusion is, like other variants of the Müller-Lyer group of illusions, due to a process of directional biasing-an extension of the concept of biasing proposed originally by Morgan et al (1990, Vision Research 30 1793 1810).

Iteration with Spreadsheets.

ERIC Educational Resources Information Center

Smith, Michael

1990-01-01

Presents several examples of the iteration method using computer spreadsheets. Examples included are simple iterative sequences and the solution of equations using the Newton-Raphson formula, linear interpolation, and interval bisection. (YP)

Tourism impacts of Three Mile Island and other adverse events: Implications for Lincoln County and other rural counties bisected by radioactive wastes intended for Yucca Mountain

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

Himmelberger, J.J.; Ogneva-Himmelberger, Y.A.; Baughman, M.

Whether the proposed Yucca Mountain nuclear waste repository system will adversely impact tourism in southern Nevada is an open question of particular importance to visitor-oriented rural counties bisected by planned waste transportation corridors (highway or rail). As part of one such county`s repository impact assessment program, tourism implications of Three Mile Island (TMI) and other major hazard events have been revisited to inform ongoing county-wide socioeconomic assessments and contingency planning efforts. This paper summarizes key research implications of such research as applied to Lincoln County, Nevada. Implications for other rural counties are discussed in light of the research findings. 29more » refs., 3 figs., 1 tab.« less

The notion of the motion: the neurocognition of motion lines in visual narratives.

PubMed

Cohn, Neil; Maher, Stephen

2015-03-19

Motion lines appear ubiquitously in graphic representation to depict the path of a moving object, most popularly in comics. Some researchers have argued that these graphic signs directly tie to the "streaks" appearing in the visual system when a viewer tracks an object (Burr, 2000), despite the fact that previous studies have been limited to offline measurements. Here, we directly examine the cognition of motion lines by comparing images in comic strips that depicted normal motion lines with those that either had no lines or anomalous, reversed lines. In Experiment 1, shorter viewing times appeared to images with normal lines than those with no lines, which were shorter than those with anomalous lines. In Experiment 2, measurements of event-related potentials (ERPs) showed that, compared to normal lines, panels with no lines elicited a posterior positivity that was distinct from the frontal positivity evoked by anomalous lines. These results suggested that motion lines aid in the comprehension of depicted events. LORETA source localization implicated greater activation of visual and language areas when understanding was made more difficult by anomalous lines. Furthermore, in both experiments, participants' experience reading comics modulated these effects, suggesting motion lines are not tied to aspects of the visual system, but rather are conventionalized parts of the "vocabulary" of the visual language of comics. Copyright © 2015 Elsevier B.V. All rights reserved.

The notion of the motion: The neurocognition of motion lines in visual narratives

PubMed Central

Cohn, Neil; Maher, Stephen

2015-01-01

Motion lines appear ubiquitously in graphic representation to depict the path of a moving object, most popularly in comics. Some researchers have argued that these graphic signs directly tie to the “streaks” appearing in the visual system when a viewer tracks an object (Burr, 2000), despite the fact that previous studies have been limited to offline measurements. Here, we directly examine the cognition of motion lines by comparing images in comic strips that depicted normal motion lines with those that either had no lines or anomalous, reversed lines. In Experiment 1, shorter viewing times appeared to images with normal lines than those with no lines, which were shorter than those with anomalous lines. In Experiment 2, measurements of event-related potentials (ERPs) showed that, compared to normal lines, panels with no lines elicited a posterior positivity that was distinct from the frontal positivity evoked by anomalous lines. These results suggested that motion lines aid in the comprehension of depicted events. LORETA source localization implicated greater activation of visual and language areas when understanding was made more difficult by anomalous lines. Furthermore, in both experiments, participants' experience reading comics modulated these effects, suggesting motion lines are not tied to aspects of the visual system, but rather are conventionalized parts of the “vocabulary” of the visual language of comics. PMID:25601006

Capture of visual direction in dynamic vergence is reduced with flashed monocular lines.

PubMed

Jaschinski, Wolfgang; Jainta, Stephanie; Schürer, Michael

2006-08-01

The visual direction of a continuously presented monocular object is captured by the visual direction of a closely adjacent binocular object, which questions the reliability of nonius lines for measuring vergence. This was shown by Erkelens, C. J., and van Ee, R. (1997a,b) [Capture of the visual direction: An unexpected phenomenon in binocular vision. Vision Research, 37, 1193-1196; Capture of the visual direction of monocular objects by adjacent binocular objects. Vision Research, 37, 1735-1745] stimulating dynamic vergence by a counter phase oscillation of two square random-dot patterns (one to each eye) that contained a smaller central dot-free gap (of variable width) with a vertical monocular line oscillating in phase with the random-dot pattern of the respective eye; subjects adjusted the motion-amplitude of the line until it was perceived as (nearly) stationary. With a continuously presented monocular line, we replicated capture of visual direction provided the dot-free gap was narrow: the adjusted motion-amplitude of the line was similar as the motion-amplitude of the random-dot pattern, although large vergence errors occurred. However, when we flashed the line for 67 ms at the moments of maximal and minimal disparity of the vergence stimulus, we found that the adjusted motion-amplitude of the line was smaller; thus, the capture effect appeared to be reduced with flashed nonius lines. Accordingly, we found that the objectively measured vergence gain was significantly correlated (r=0.8) with the motion-amplitude of the flashed monocular line when the separation between the line and the fusion contour was at least 32 min arc. In conclusion, if one wishes to estimate the dynamic vergence response with psychophysical methods, effects of capture of visual direction can be reduced by using flashed nonius lines.

Absolute Wavelength Calibration of the IDSII Spectrometer for Impurity Ion Velocity Measurements in the MST

NASA Astrophysics Data System (ADS)

Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; MST Team

2014-10-01

The MST operates two Ion Doppler Spectrometers (IDS) for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometers record data within 0.3 nm of the line of interest, and commercial calibration lamps do not produce lines in this narrow range . Four calibration methods were investigated. First, emission along the chord bisecting the poloidal plane was measured as it should have no time-averaged Doppler shift. Second, a calibrated CCD spectrometer and the IDSII were used to observe the same plasma from opposing sides so as to measure opposite Doppler shifts. The unshifted line is located halfway between the two opposing measurements. Third, the two fibers of the IDSI were positioned to take absolute flow measurements using opposing views. Substituting the IDSII for one of the IDSI fibers, absolute measurements of flow from the IDSI were used to calibrate the IDSII. Finally, an optical system was designed to filter an ultraviolet LED, providing a known wavelength source within the spectral range covered by the IDSII. The optical train is composed of an air-gapped etalon and fused silica lenses. The quality of calibration for each of these methods is analyzed and their results compared. Preliminary impurity ion velocity measurements are shown. This work has been supported by the US DOE and the NSF.

New side-view imaging technique for observing posterior chamber structures during cataract surgery in porcine eyes

PubMed Central

2013-01-01

Background To develop a side-view imaging technique for observing the dynamic behavior of posterior chamber structures (PCSs) in porcine eyes which mimics closed-eye cataract surgery in humans. Methods Enucleated porcine eyes were placed into liquid nitrogen for 5 seconds and immediately bisected at about a 45-degree angle to the equatorial plane. The anterior portion was attached firmly to a glass slide with superglue and sprinkled with wheat flour. Phacoemulsification and aspiration (PEA) was performed as in humans on 10 consecutive porcine eyes. The movements of the PCSs were monitored through the glass slide with a high-resolution video camera set below the cut surface of the eye. The intraocular pressure (IOP) was monitored during the surgery. The highest IOP, operation time, and volume of irrigation fluid of 10 whole eyes were compared to that obtained from the bisected eyes glued to a glass slide. In a second set of experiments, the strength of the seal between the bisected eye and the glass slide was tested in three sets of eyes: 1) frozen eye fixed with superglue with wheat flour for 3 min; 2) frozen eye fixed with superglue for 3 min; and 3) non-frozen eye fixed with superglue for 30 min. The highest IOP that led to a disruption of the seal was compared among the three groups. Results PEA was successfully performed on 9 of 10 (90%) eyes with the movements of the PCSs clearly observed. The average maximum intraocular pressure of the 9 bisected eyes was 55.8 ± 4.7 mmHg and that for the 10 unbisected eyes was 55.3 ± 5.0 mmHg (P = 0.650). The frozen eye fixed with superglue in combination with wheat flour (Group 1) had the strongest sealing strength with an average IOP at the breaking point of 117.3 ± 36.2 mmHg. Conclusions Our side-view imaging technique can be used to evaluate the changes of the PCSs during intraocular surgery and for surgical training of new residents. PMID:24053470

Immortal solution of the Ricci flow

NASA Astrophysics Data System (ADS)

Ruan, Qihua; Chen, Zhihua

2005-12-01

For any complete noncompact K$\\ddot{a}$hler manifold with nonnegative and bounded holomorphic bisectional curvature,we provide the necessary and sufficient condition for non-ancient solution to the Ricci flow in this paper.

Reliable use of determinants to solve nonlinear structural eigenvalue problems efficiently

NASA Technical Reports Server (NTRS)

Williams, F. W.; Kennedy, D.

1988-01-01

The analytical derivation, numerical implementation, and performance of a multiple-determinant parabolic interpolation method (MDPIM) for use in solving transcendental eigenvalue (critical buckling or undamped free vibration) problems in structural mechanics are presented. The overall bounding, eigenvalue-separation, qualified parabolic interpolation, accuracy-confirmation, and convergence-recovery stages of the MDPIM are described in detail, and the numbers of iterations required to solve sample plane-frame problems using the MDPIM are compared with those for a conventional bisection method and for the Newtonian method of Simpson (1984) in extensive tables. The MDPIM is shown to use 31 percent less computation time than bisection when accuracy of 0.0001 is required, but 62 percent less when accuracy of 10 to the -8th is required; the time savings over the Newtonian method are about 10 percent.

Patterns of innervation of the lacrimal gland with clinical application.

PubMed

Scott, Gabriel; Balsiger, Heather; Kluckman, Matthew; Fan, Jerry; Gest, Thomas

2014-11-01

Parasympathetic stimulation of the lacrimal gland is responsible for tear production, and this innervation originates from fibers conveyed in the facial nerve. After synapse in the pterygopalatine ganglion, postsynaptic parasympathetic fibers travel within the zygomatic and zygomaticotemporal nerves (ZTN) into the orbit. As described in most anatomy texts, ZTN communicates with the lacrimal nerve (LN) posterior to the gland and then secretomotor fibers enter the gland. This study was performed to gain a better understanding of the innervation of the lacrimal gland. Seventeen cadaver heads were bisected for a total of 34 sides, which then underwent dissection of the superolateral orbital region to observe the course for the LN and ZTN. Three variations of the course of the LN and ZTN were found. In 20 (60.6%) dissections it was documented that the ZTN entered directly into the lacrimal gland with no communication with the LN. In 12 (36.4%) of the bisected heads, ZTN had both a direct connection into the gland and a communicating branch with the LN. In only one (3.0%) bisected head, ZTN communicated with the LN before entering the gland as it is commonly described in anatomy texts. Our study reveals that the ZTN usually takes a different course than is classically described in most anatomy textbooks. A greater understanding of the typical course these nerves take may help surgeons identify them more easily and avoid damaging them. © 2014 Wiley Periodicals, Inc.

Association between measures of patella height, morphologic features of the trochlea, and patellofemoral joint alignment: the MOST study.

PubMed

Stefanik, Joshua J; Zumwalt, Ann C; Segal, Neil A; Lynch, John A; Powers, Christopher M

2013-08-01

Patellofemoral joint (PFJ) malalignment (lateral patella displacement and tilt) has been proposed as a cause of patellofemoral pain. Patella height and/or the morphologic features of the femoral trochlea may predispose one to patella malalignment. The purposes of our study were to assess the associations among patella height, morphologic features of the trochlea, and measures of PFJ alignment and to determine which measures of patella height and morphologic features of the trochlea were the best predictors of PFJ alignment. Measures of patella height (Insall-Salvati ratio and modified Insall-Salvati ratio), morphologic features of the trochlea (sulcus angle, trochlear angle, lateral trochlear inclination, medial trochlear inclination), and PFJ alignment (bisect offset and patella tilt angle) were assessed in 566 knees from the Multicenter Osteoarthritis Study. Bisect offset was correlated with the Insall-Salvati ratio (r = 0.25) and lateral trochlear inclination (r = -0.38). Patella tilt angle correlated with the trochlear angle (-0.27) and lateral trochlear inclination (-0.32). Linear regression models including the Insall-Salvati ratio and lateral trochlear inclination explained 20% and 11% of the variance in bisect offset and patella tilt angle, respectively. Of the variables measured in the current study, the Insall-Salvati ratio and lateral trochlear inclination were the best predictors of lateral patella displacement and lateral tilt. This knowledge will aid clinicians in the identification of anatomic risk factors for PFJ malalignment and/or PFJ dysfunction.

Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

PubMed Central

Laugharne, Edward; Bali, Navi; Purushothamdas, Sanjay; Almallah, Faris; Kundra, Rik

2016-01-01

Purpose The purpose of this study was to investigate the impact of varying knee flexion and quadriceps activity on patellofemoral indices measured on magnetic resonance imaging (MRI). Materials and Methods MRI of the knee was performed in 20 patients for indications other than patellar or patellofemoral pathology. Axial and sagittal sequences were performed in full extension of the knee with the quadriceps relaxed, full extension of the knee with the quadriceps contracted, 30° flexion of the knee with the quadriceps relaxed, and 30° flexion with the quadriceps contracted. Bisect offset, patella tilt angle, Insall-Salvati ratio and Caton-Deschamps index were measured. Results With the knee flexed to 30° and quadriceps relaxed, the mean values of patellar tilt angle, bisect offset, Insall-Salvati ratio and Caton-Deschamps index were all within normal limits. With the knee extended and quadriceps contracted, the mean patellar tilt angle (normal value, <15°) was 14.6° and the bisect offset (normal value, <65%) was 65%, while the Caton-Deschamps index was 1.34 (normal range, 0.6 to 1.3). With the knee extended and quadriceps relaxed, the mean Caton-Deschamps index was 1.31. Conclusions MRI scanning of the knee in extension with the quadriceps contracted leads to elevated patellofemoral indices. MRI taken with the knee in 30° of flexion allows more reliable assessment of the patellofemoral joint and minimises the confounding effect of quadriceps contraction. PMID:27894177

An approach to successful freezing of demi-embryos derived from day-7 bovine embryos.

PubMed

Niemann, H; Brem, G; Sacher, B; Smidt, D; Kräusslich, H

1986-04-01

The developmental capacity of frozen/thawed bisected embryos (n = 33) derived from day-7 bovine embryos was investigated and compared to ordinary embryos after freezing and thawing (n = 28) and to freshly bisected embryos (n = 19). The freezing and thawing protocol was identical for ordinary and demi-embryos. The percentage of intact embryos classified as excellent, good, or poor after thawing was 92.9 and 96.3% for ordinary and demi-embryos, respectively. Pregnancy rates of 53.8 (8 15 ), 46.2 (6 13 ), and 47.5% (9 19 ) were obtained when frozen/thawed ordinary embryos and frozen/thawed demi-embryos classified as excellent or good and sealed with an additional zona pellucida from hatched pig blastocysts or freshly bisected embryos were transferred. One pair of identical twins resulted from the transfer of frozen/thawed demi-embryos sealed with an additional zona pellucida. Transfer of four frozen/thawed demi-embryos without an additional zona pellucida led to one pregnancy. In contrast, demi-embryos derived from frozen/thawed ordinary embryos (n = 8) as well as frozen/thawed demi-embryos classified as poor (n = 6) did not result in any pregnancies although two halves were transferred per recipient. It is concluded that sealing the punctured zona pellucida improves the developmental capacity of frozen/thawed demi-embryos derived from day-7 bovine embryos, and freezing demi-embryos is more efficient compared to the splitting of frozen/thawed ordinary embryos.

In vitro survival of fresh and frozen/thawed bovine demi-embryos.

PubMed

Lucas-Hahn, A; Niemann, H

1991-10-01

Three experiments were conducted to investigate the effects of type of culture medium in freshly bisected bovine embryos and the effects of agar embedding and of 1.2 propanediol (PROH) as the cryoprotectant in frozen/thawed bisected bovine embryos on development in vitro. A total of 265 bovine embryos were used as controls or were microsurgically bisected and were cultured in vitro for 48 hours and development was determined 24 and 48 hours after the onset of culture. Whitten's medium supported more (P<0.05) intact and demi-embryos to grow to expanded blastocysts (92.9 and 73.1%, respectively) compared with Ham's F10 (43.8 and 26.3%, respectively) and PBS (53.8 and 12.5%, respectively). Embedding in agar and culture in Whitten's medium resulted in a higher (P<0.05) percentage of in vitro development of frozen/thawed demi-embryos after 24 hours than the freezing of nonembedded demi-embryos (44.1 versus 19.6%, respectively). This difference disappeared, however, after a 48 hours culture period (17.6 versus 11.8%, respectively). Following freezing in PROH, survival rates of 40 and 28%, respectively after 24 hours of culture were obtained for intact and demi-embryos. The respective percentages after 48 hours were 8.6 and 16%. Since neither embedding in agar nor the use of PROH as the cryoprotectant resulted in high survival rates of frozen/thawed demi-embryos in vitro, new freezing procedures are needed to overcome the sensitivity of demi-embryos to freezing and thawing.

Comparison of animated jet stream visualizations

NASA Astrophysics Data System (ADS)

Nocke, Thomas; Hoffmann, Peter

2016-04-01

The visualization of 3D atmospheric phenomena in space and time is still a challenging problem. In particular, multiple solutions of animated jet stream visualizations have been produced in recent years, which were designed to visually analyze and communicate the jet and related impacts on weather circulation patterns and extreme weather events. This PICO integrates popular and new jet animation solutions and inter-compares them. The applied techniques (e.g. stream lines or line integral convolution) and parametrizations (color mapping, line lengths) are discussed with respect to visualization quality criteria and their suitability for certain visualization tasks (e.g. jet patterns and jet anomaly analysis, communicating its relevance for climate change).

[Peculiarities of visual perception of dentition and smile aesthetic parameters].

PubMed

Riakhovskiĭ, A N; Usanova, E V

2007-01-01

As the result of the studies it was determined in which limits the dentition central line displacement from the face middle line and the change of smile line tilt angle become noticeable for visual perception. And also how much visual perception of the dentition aesthetic parameters were differed in doctors with different experience, dental technicians and patients.

[Grid laser photocoagulation in diffuse diabetic macular edema].

PubMed

Degenring, Robert F; Hugger, Philipp; Sauder, Gangolf; Jonas, Jost B

2004-01-01

To evaluate the clinical outcome of macular grid laser photocoagulation in the treatment of diffuse diabetic macular oedema. The retrospective study included 30 consecutive patients (41 eyes) who were treated by macular argon green grid laser photocoagulation for diffuse diabetic macular oedema. Follow-up time was 31.4 +/- 19.6 weeks. Visual acuity decreased from 0.25 +/- 0.18 (range, 0.03 - 0.8) to 0.20 +/- 0.18 (range, 0.02 - 0.8) (P = 0.045), representing a change of - 0.9 +/- 2,32 lines. 5 (12.2 %) eyes gained in visual acuity, visual acuity remained unchanged for 23 (56.1 %) eyes, and 13 (31.7 %) eyes showed a visual loss of more than one line. In eyes with a baseline visual acuity > or = 0.2 (N = 24) visual acuity dropped from 0.36 +/- 0.15 (0.2 - 0.8; median 0.3) to 0.29 +/- 0.19 (0.05 - 0.8; median 0.2) (p = 0.038). 3 eyes (12.5 %) gained > or = 2 lines, 11 eyes (45.8 %) lost > or = 2 lines, 10 eyes (41.7 %) remained stable. Mean loss was - 1.63 +/- 2.53 lines. Eyes with a baseline visual acuity < or = 0.2 did not change significantly. In the present study mean visual acuity decreased in the whole population and especially in the subgroup with a baseline visual acuity of > or = 0.2 after macular grid laser photocoagulation for diffuse diabetic macular oedema. Mean visual loss was just below the predefined 2 lines. In view of these results and upcoming new pharmacological and surgical treatment modalities, the significance of grid laser photocoagulation should be re-discussed.

Are there right hemisphere contributions to visually-guided movement? Manipulating left hand reaction time advantages in dextrals.

PubMed

Carey, David P; Otto-de Haart, E Grace; Buckingham, Gavin; Dijkerman, H Chris; Hargreaves, Eric L; Goodale, Melvyn A

2015-01-01

Many studies have argued for distinct but complementary contributions from each hemisphere in the control of movements to visual targets. Investigators have attempted to extend observations from patients with unilateral left- and right-hemisphere damage, to those using neurologically-intact participants, by assuming that each hand has privileged access to the contralateral hemisphere. Previous attempts to illustrate right hemispheric contributions to the control of aiming have focussed on increasing the spatial demands of an aiming task, to attenuate the typical right hand advantages, to try to enhance a left hand reaction time advantage in right-handed participants. These early attempts have not been successful. The present study circumnavigates some of the theoretical and methodological difficulties of some of the earlier experiments, by using three different tasks linked directly to specialized functions of the right hemisphere: bisecting, the gap effect, and visuospatial localization. None of these tasks were effective in reducing the magnitude of left hand reaction time advantages in right handers. Results are discussed in terms of alternatives to right hemispheric functional explanations of the effect, the one-dimensional nature of our target arrays, power and precision given the size of the left hand RT effect, and the utility of examining the proportions of participants who show these effects, rather than exclusive reliance on measures of central tendency and their associated null hypothesis significance tests.

Are there right hemisphere contributions to visually-guided movement? Manipulating left hand reaction time advantages in dextrals

PubMed Central

Carey, David P.; Otto-de Haart, E. Grace; Buckingham, Gavin; Dijkerman, H. Chris; Hargreaves, Eric L.; Goodale, Melvyn A.

2015-01-01

Many studies have argued for distinct but complementary contributions from each hemisphere in the control of movements to visual targets. Investigators have attempted to extend observations from patients with unilateral left- and right-hemisphere damage, to those using neurologically-intact participants, by assuming that each hand has privileged access to the contralateral hemisphere. Previous attempts to illustrate right hemispheric contributions to the control of aiming have focussed on increasing the spatial demands of an aiming task, to attenuate the typical right hand advantages, to try to enhance a left hand reaction time advantage in right-handed participants. These early attempts have not been successful. The present study circumnavigates some of the theoretical and methodological difficulties of some of the earlier experiments, by using three different tasks linked directly to specialized functions of the right hemisphere: bisecting, the gap effect, and visuospatial localization. None of these tasks were effective in reducing the magnitude of left hand reaction time advantages in right handers. Results are discussed in terms of alternatives to right hemispheric functional explanations of the effect, the one-dimensional nature of our target arrays, power and precision given the size of the left hand RT effect, and the utility of examining the proportions of participants who show these effects, rather than exclusive reliance on measures of central tendency and their associated null hypothesis significance tests. PMID:26379572

Bisectional fault detection system

DOEpatents

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2012-02-14

An apparatus, program product and method logically divide a group of nodes and causes node pairs comprising a node from each section to communicate. Results from the communications may be analyzed to determine performance characteristics, such as bandwidth and proper connectivity.

Bisectional fault detection system

DOEpatents

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2009-08-04

An apparatus and program product logically divide a group of nodes and causes node pairs comprising a node from each section to communicate. Results from the communications may be analyzed to determine performance characteristics, such as bandwidth and proper connectivity.

Bisectional fault detection system

DOEpatents

Archer, Charles Jens [Rochester, MN; Pinnow, Kurt Walter [Rochester, MN; Ratterman, Joseph D [Rochester, MN; Smith, Brian Edward [Rochester, MN

2008-11-11

An apparatus, program product and method logically divides a group of nodes and causes node pairs comprising a node from each section to communicate. Results from the communications may be analyzed to determine performance characteristics, such as bandwidth and proper connectivity.

On global optimization using an estimate of Lipschitz constant and simplicial partition

NASA Astrophysics Data System (ADS)

Gimbutas, Albertas; Žilinskas, Antanas

2016-10-01

A new algorithm is proposed for finding the global minimum of a multi-variate black-box Lipschitz function with an unknown Lipschitz constant. The feasible region is initially partitioned into simplices; in the subsequent iteration, the most suitable simplices are selected and bisected via the middle point of the longest edge. The suitability of a simplex for bisection is evaluated by minimizing of a surrogate function which mimics the lower bound for the considered objective function over that simplex. The surrogate function is defined using an estimate of the Lipschitz constant and the objective function values at the vertices of a simplex. The novelty of the algorithm is the sophisticated method of estimating the Lipschitz constant, and the appropriate method to minimize the surrogate function. The proposed algorithm was tested using 600 random test problems of different complexity, showing competitive results with two popular advanced algorithms which are based on similar assumptions.

Joint Optimization of Receiver Placement and Illuminator Selection for a Multiband Passive Radar Network.

PubMed

Xie, Rui; Wan, Xianrong; Hong, Sheng; Yi, Jianxin

2017-06-14

The performance of a passive radar network can be greatly improved by an optimal radar network structure. Generally, radar network structure optimization consists of two aspects, namely the placement of receivers in suitable places and selection of appropriate illuminators. The present study investigates issues concerning the joint optimization of receiver placement and illuminator selection for a passive radar network. Firstly, the required radar cross section (RCS) for target detection is chosen as the performance metric, and the joint optimization model boils down to the partition p -center problem (PPCP). The PPCP is then solved by a proposed bisection algorithm. The key of the bisection algorithm lies in solving the partition set covering problem (PSCP), which can be solved by a hybrid algorithm developed by coupling the convex optimization with the greedy dropping algorithm. In the end, the performance of the proposed algorithm is validated via numerical simulations.

Separated-orbit bisected energy-recovered linear accelerator

DOEpatents

Douglas, David R.

2015-09-01

A separated-orbit bisected energy-recovered linear accelerator apparatus and method. The accelerator includes a first linac, a second linac, and a plurality of arcs of differing path lengths, including a plurality of up arcs, a plurality of downgoing arcs, and a full energy arc providing a path independent of the up arcs and downgoing arcs. The up arcs have a path length that is substantially a multiple of the RF wavelength and the full energy arc includes a path length that is substantially an odd half-integer multiple of the RF wavelength. Operation of the accelerator includes accelerating the beam utilizing the linacs and up arcs until the beam is at full energy, at full energy executing a full recirculation to the second linac using a path length that is substantially an odd half-integer of the RF wavelength, and then decelerating the beam using the linacs and downgoing arcs.

Hemispheric differences in visual search of simple line arrays.

PubMed

Polich, J; DeFrancesco, D P; Garon, J F; Cohen, W

1990-01-01

The effects of perceptual organization on hemispheric visual-information processing were assessed with stimulus arrays composed of short lines arranged in columns. A visual-search task was employed in which subjects judged whether all the lines were vertical (same) or whether a single horizontal line was present (different). Stimulus-display organization was manipulated in two experiments by variation of line density, linear organization, and array size. In general, left-visual-field/right-hemisphere presentations demonstrated more rapid and accurate responses when the display was perceived as a whole. Right-visual-field/left-hemisphere superiorities were observed when the display organization coerced assessment of individual array elements because the physical qualities of the stimulus did not effect a gestalt whole. Response times increased somewhat with increases in array size, although these effects interacted with other stimulus variables. Error rates tended to follow the reaction-time patterns. The results suggest that laterality differences in visual search are governed by stimulus properties which contribute to, or inhibit, the perception of a display as a gestalt. The implications of these findings for theoretical interpretations of hemispheric specialization are discussed.

Plastic pollution in the South Pacific subtropical gyre.

PubMed

Eriksen, Marcus; Maximenko, Nikolai; Thiel, Martin; Cummins, Anna; Lattin, Gwen; Wilson, Stiv; Hafner, Jan; Zellers, Ann; Rifman, Samuel

2013-03-15

Plastic marine pollution in the open ocean of the southern hemisphere is largely undocumented. Here, we report the result of a (4489 km) 2424 nautical mile transect through the South Pacific subtropical gyre, carried out in March-April 2011. Neuston samples were collected at 48 sites, averaging 50 nautical miles apart, using a manta trawl lined with a 333 μm mesh. The transect bisected a predicted accumulation zone associated with the convergence of surface currents, driven by local winds. The results show an increase in surface abundance of plastic pollution as we neared the center and decrease as we moved away, verifying the presence of a garbage patch. The average abundance and mass was 26,898 particles km(-2) and 70.96 g km(-2), respectively. 88.8% of the plastic pollution was found in the middle third of the samples with the highest value of 396,342 particles km(-2) occurring near the center of the predicted accumulation zone. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cultural influence on directional tendencies in children's drawing.

PubMed

Portex, Marine; Foulin, Jean-Noël; Troadec, Bertrand

2017-09-01

The present study was aimed at investigating how print experience as a cultural factor influences directional tendencies in children's drawing in the interplay with biomechanical (hand), syntactic (shape orientation) and semantic (shape meaning) factors. Eighty-eight right-handed children from three literacy/age groups (preliterate, first graders and third graders) had to copy a geometrical shape adapted from the Rey-Osterrieth complex figure. The shape was presented alternatively leftward and rightward, while using both dominant (right) and non-dominant (left) hands. Directional tendencies were assessed regarding directionality of drawing movements at global, intermediate and local levels and deviation error in centre line bisection. Results show a global improvement of drawing quality and strategies across groups and an advantage for the dominant right hand from 6 years onward. Regarding directional tendencies, a reinforcement of a congruency effect between conditions and writing direction was found from preliterates to third graders. These results are discussed as a cultural embodiment process and have implications for psychological testing.

From Concrete to Abstract in the Measurement of Length

NASA Astrophysics Data System (ADS)

Stephanou, Andreas; Fisher, William P., Jr.

2013-09-01

The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct.

Fine lattice lines on the corneal surface after laser in situ keratomileusis (LASIK).

PubMed

Carpel, E F; Carlson, K H; Shannon, S

2000-03-01

To present an example of a pattern of lines resembling fine lattice on the corneal surface subsequent to laser in situ keratomileusis (LASIK). This subtle phenomenon may be relatively common and may affect visual outcome. Case report. A 41-year-old year old man with high myopia and best-corrected visual acuity of 20/20 +2 in each eye underwent laser in situ keratomileusis (LASIK). No operative or postoperative complications occurred. No striae were evident on slit-lamp examination with direct illumination and retroillumination at the time of surgery or in the postoperative period. Postoperative uncorrected visual acuity was 20/25 with a best-corrected spectacle correction of 20/25 in both eyes. Fine lines in a lattice pattern were seen only with fluorescein dye in the precorneal tear film as areas of "negative stain" within the LASIK flap. With tear film supplementation, the lines were less evident and visual acuity improved. One year postoperatively, his uncorrected visual acuity was 20/25 in both eyes. The best-corrected spectacle visual acuity was RE: 20/20 -2, LE: 20/25. The fine lines were still present within the flap. A soft contact lens improved visual acuity to 20/20 in both eyes. Although all four puncta were occluded, he had no epiphora. Fine lines in a lattice pattern that may represent folds in the epithelium or Bowman layer may be present within the flap after LASIK and may adversely affect visual acuity. They may be visible as areas of negative stain with fluorescein dye in the precorneal tear film in the absence of any striae visible in the flap. These superficial lines have been seen more in patients with high degrees of correction and in patients with dry eye. If visual acuity is affected, it may be improved with punctal occlusion, tear supplements, or a contact lens.

Neural model for processing the influence of visual orientation on visually perceived eye level (VPEL).

PubMed

Matin, L; Li, W

2001-10-01

An individual line or a combination of lines viewed in darkness has a large influence on the elevation to which an observer sets a target so that it is perceived to lie at eye level (VPEL). These influences are systematically related to the orientation of pitched-from-vertical lines on pitched plane(s) and to the lengths of the lines, as well as to the orientations of lines of 'equivalent pitch' that lie on frontoparallel planes. A three-stage model processes the visual influence: The first stage parallel processes the orientations of the lines utilizing 2 classes of orientation-sensitive neural units in each hemisphere, with the two classes sensitive to opposing ranges of orientations; the signal delivered by each class is of opposite sign in the two hemispheres. The second stage generates the total visual influence from the parallel combination of inputs delivered by the 4 groups of the first stage, and a third stage combines the total visual influence from the second stage with signals from the body-referenced mechanism that contains information about the position and orientation of the eyes, head, and body. The circuit equation describing the combined influence of n separate inputs from stage 1 on the output of the stage 2 integrating neuron is derived for n stimulus lines which possess any combination of orientations and lengths; Each of the n lines is assumed to stimulate one of the groups of orientation-sensitive units in visual cortex (stage 1) whose signals converge on to a dendrite of the integrating neuron (stage 2), and to produce changes in postsynaptic membrane conductance (g(i)) and potential (V(i)) there. The net current from the n dendrites results in a voltage change (V(A)) at the initial segment of the axon of the integrating neuron. Nerve impulse frequency proportional to this voltage change signals the total visual influence on perceived elevation of the visual field. The circuit equation corresponding to the total visual influence for n equal length inducing lines is V(A)= sum V(i)/[n+(g(A)/g(S))], where the potential change due to line i, V(i), is proportional to line orientation, g(A) is the conductance at the axon's summing point, and g(S)=g(i) for each i for the equal length case; the net conductance change due to a line is proportional to the line's length. The circuit equation is interpreted as a basis for quantitative predictions from the model that can be compared to psychophysical measurements of the elevation of VPEL. The interpretation provides the predicted relation for the visual influence on VPEL, V, by n inducing lines each with length l: thus, V=a+[k(i) sum theta(i)/n+(k(2)/l)], where theta(i) is the orientation of line i, a is the effect of the body-referenced mechanism, and k(1) and k(2) are constants. The model's output is fitted to the results of five sets of experiments in which the elevation of VPEL measured with a small target in the median plane is systematically influenced by distantly located 1-line or 2-line inducing stimuli varying in orientation and length and viewed in otherwise total darkness with gaze restricted to the median plane; each line is located at either 25 degrees eccentricity to the left or right of the median plane. The model predicts the negatively accelerated growth of VPEL with line length for each orientation and the change of slope constant of the linear combination rule among lines from 1.00 (linear summation; short lines) to 0.61 (near-averaging; long lines). Fits to the data are obtained over a range of orientations from -30 degrees to +30 degrees of pitch for 1-line visual fields from lengths of 3 degrees to 64 degrees, for parallel 2-line visual fields over the same range of lengths and orientations, for short and long 2-line combinations in which each of the two members may have any orientation (parallel or nonparallel pairs), and for the well-illuminated and fully structured pitchroom. In addition, similar experiments with 2-line stimuli of equivalent pitch in the frontoparallel plane were also fitted to the model. The model accounts for more than 98% of the variance of the results in each case.

Development of cortical orientation selectivity in the absence of visual experience with contour

PubMed Central

Hussain, Shaista; Weliky, Michael

2011-01-01

Visual cortical neurons are selective for the orientation of lines, and the full development of this selectivity requires natural visual experience after eye opening. Here we examined whether this selectivity develops without seeing lines and contours. Juvenile ferrets were reared in a dark room and visually trained by being shown a movie of flickering, sparse spots. We found that despite the lack of contour visual experience, the cortical neurons of these ferrets developed strong orientation selectivity and exhibited simple-cell receptive fields. This finding suggests that overt contour visual experience is unnecessary for the maturation of orientation selectivity and is inconsistent with the computational models that crucially require the visual inputs of lines and contours for the development of orientation selectivity. We propose that a correlation-based model supplemented with a constraint on synaptic strength dynamics is able to account for our experimental result. PMID:21753023

The development of a white cane which navigates the visually impaired.

PubMed

Shiizu, Yuriko; Hirahara, Yoshiaki; Yanashima, Kenji; Magatani, Kazushige

2007-01-01

In this paper, we describe about a developed navigation system that supports the independent walking of the visually impaired in the indoor space. This system is composed of colored navigation lines, RFID tags and an intelligent white cane. In our system, some colored marking tapes are set on along the walking route. These lines are called navigation line. And also RFID tags are set on this line at each landmark point. The intelligent white cane can sense a color of navigation line and receive tag information. By vibration of white cane, the system informs the visually impaired that he/she is walking along the navigation line. At the landmark point, the system also notifies area information to him/her by pre-recorded voice. Ten normal subjects who were blind folded with an eye mask were tested with this system. All of them were able to walk along the navigation line. The performance of the area information system was good. Therefore, we have concluded that our system will be extremely valuable in supporting the activities of the visually impaired.

Bionic Vision-Based Intelligent Power Line Inspection System

PubMed Central

Ma, Yunpeng; He, Feijia; Xu, Jinxin

2017-01-01

Detecting the threats of the external obstacles to the power lines can ensure the stability of the power system. Inspired by the attention mechanism and binocular vision of human visual system, an intelligent power line inspection system is presented in this paper. Human visual attention mechanism in this intelligent inspection system is used to detect and track power lines in image sequences according to the shape information of power lines, and the binocular visual model is used to calculate the 3D coordinate information of obstacles and power lines. In order to improve the real time and accuracy of the system, we propose a new matching strategy based on the traditional SURF algorithm. The experimental results show that the system is able to accurately locate the position of the obstacles around power lines automatically, and the designed power line inspection system is effective in complex backgrounds, and there are no missing detection instances under different conditions. PMID:28203269

Solution of Cubic Equations by Iteration Methods on a Pocket Calculator

ERIC Educational Resources Information Center

Bamdad, Farzad

2004-01-01

A method to provide students a vision of how they can write iteration programs on an inexpensive programmable pocket calculator, without requiring a PC or a graphing calculator is developed. Two iteration methods are used, successive-approximations and bisection methods.

Impact of cycling cells and cell cycle regulation on Hydra regeneration.

PubMed

Buzgariu, Wanda; Wenger, Yvan; Tcaciuc, Nina; Catunda-Lemos, Ana-Paula; Galliot, Brigitte

2018-01-15

Hydra tissues are made from three distinct populations of stem cells that continuously cycle and pause in G2 instead of G1. To characterize the role of cell proliferation after mid-gastric bisection, we have (i) used flow cytometry and classical markers to monitor cell cycle modulations, (ii) quantified the transcriptomic regulations of 202 genes associated with cell proliferation during head and foot regeneration, and (iii) compared the impact of anti-proliferative treatments on regeneration efficiency. We confirm two previously reported events: an early mitotic wave in head-regenerating tips, when few cell cycle genes are up-regulated, and an early-late wave of proliferation on the second day, preceded by the up-regulation of 17 cell cycle genes. These regulations appear more intense after mid-gastric bisection than after decapitation, suggesting a position-dependent regulation of cell proliferation during head regeneration. Hydroxyurea, which blocks S-phase progression, delays head regeneration when applied before but not after bisection. This result is consistent with the fact that the Hydra central region is enriched in G2-paused adult stem cells, poised to divide upon injury, thus forming a necessary constitutive pro-blastema. However a prolonged exposure to hydroxyurea does not block regeneration as cells can differentiate apical structures without traversing S-phase, and also escape in few days the hydroxyurea-induced S-phase blockade. Thus Hydra head regeneration, which is a fast event, is highly plastic, relying on large stocks of adult stem cells paused in G2 at amputation time, which immediately divide to proliferate and/or differentiate apical structures even when S-phase is blocked. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Derivation of two functional X chromosome centromeres from a single break bisecting the centromere of origin: Implications for centromere structure

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

Schonberg, S.A.; Quarles, C.; Tifft, C.

1994-09-01

The precise nature of the functional human centromeric sequences remains a matter of some controversy. Evidence has accumulated over the past several years that directly implicates alphoid repeats as a critical component. We report a child with dysmorphic features consistent with the recently described small ring X syndrome, with a constitutional karyotype that addresses this issue. At 5 1/2 months, the patient was a small, hypotonic, delayed female with brachycephaly, a broad forehead, prominent nasal root, synophorous, small mouth, and cup-shaped ears with prominent lobules, as well as microcornea, and pendular nystagmus. Hand abnormalities included single palmar creases and shortmore » tapered fingers. In addition to mosaicism for a small ring chromosome derived from the proximal short arm of the X, the proband has, in all cells, a monocentric isochromosome for the long arm of the X. The karyotype is interpreted as 46,X,iso(Xq)/47,X,iso(Xq),r(Xp11cen). We present routine karyotypic and FISH analysis of the rearranged X chromosomes. We propose that the only mechanism consistent with this karyotype is that of a two-break rearrangement with one break bisecting a centromere in such a way as to retain functional centromeric activity in each of the separated regions. The second break, proximal in the short arm, allows for ring chromosome formation with the bisected centromere. The iso(Xq) arises by the classical mechanism of post-replication sister-reunion. The formation of two functional centromeres by a single break through the {open_quotes}parental{close_quotes} centromere indicates that the functional activity must be in a repeated component of the centromeric DNA and argues strongly against the requirement for any single gene in cis orientation.« less

Immunoglobulin G (IgG) Fab glycosylation analysis using a new mass spectrometric high-throughput profiling method reveals pregnancy-associated changes.

PubMed

Bondt, Albert; Rombouts, Yoann; Selman, Maurice H J; Hensbergen, Paul J; Reiding, Karli R; Hazes, Johanna M W; Dolhain, Radboud J E M; Wuhrer, Manfred

2014-11-01

The N-linked glycosylation of the constant fragment (Fc) of immunoglobulin G has been shown to change during pathological and physiological events and to strongly influence antibody inflammatory properties. In contrast, little is known about Fab-linked N-glycosylation, carried by ∼ 20% of IgG. Here we present a high-throughput workflow to analyze Fab and Fc glycosylation of polyclonal IgG purified from 5 μl of serum. We were able to detect and quantify 37 different N-glycans by means of MALDI-TOF-MS analysis in reflectron positive mode using a novel linkage-specific derivatization of sialic acid. This method was applied to 174 samples of a pregnancy cohort to reveal Fab glycosylation features and their change with pregnancy. Data analysis revealed marked differences between Fab and Fc glycosylation, especially in the levels of galactosylation and sialylation, incidence of bisecting GlcNAc, and presence of high mannose structures, which were all higher in the Fab portion than the Fc, whereas Fc showed higher levels of fucosylation. Additionally, we observed several changes during pregnancy and after delivery. Fab N-glycan sialylation was increased and bisection was decreased relative to postpartum time points, and nearly complete galactosylation of Fab glycans was observed throughout. Fc glycosylation changes were similar to results described before, with increased galactosylation and sialylation and decreased bisection during pregnancy. We expect that the parallel analysis of IgG Fab and Fc, as set up in this paper, will be important for unraveling roles of these glycans in (auto)immunity, which may be mediated via recognition by human lectins or modulation of antigen binding. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Immunoglobulin G (IgG) Fab Glycosylation Analysis Using a New Mass Spectrometric High-throughput Profiling Method Reveals Pregnancy-associated Changes*

PubMed Central

Bondt, Albert; Rombouts, Yoann; Selman, Maurice H. J.; Hensbergen, Paul J.; Reiding, Karli R.; Hazes, Johanna M. W.; Dolhain, Radboud J. E. M.; Wuhrer, Manfred

2014-01-01

The N-linked glycosylation of the constant fragment (Fc) of immunoglobulin G has been shown to change during pathological and physiological events and to strongly influence antibody inflammatory properties. In contrast, little is known about Fab-linked N-glycosylation, carried by ∼20% of IgG. Here we present a high-throughput workflow to analyze Fab and Fc glycosylation of polyclonal IgG purified from 5 μl of serum. We were able to detect and quantify 37 different N-glycans by means of MALDI-TOF-MS analysis in reflectron positive mode using a novel linkage-specific derivatization of sialic acid. This method was applied to 174 samples of a pregnancy cohort to reveal Fab glycosylation features and their change with pregnancy. Data analysis revealed marked differences between Fab and Fc glycosylation, especially in the levels of galactosylation and sialylation, incidence of bisecting GlcNAc, and presence of high mannose structures, which were all higher in the Fab portion than the Fc, whereas Fc showed higher levels of fucosylation. Additionally, we observed several changes during pregnancy and after delivery. Fab N-glycan sialylation was increased and bisection was decreased relative to postpartum time points, and nearly complete galactosylation of Fab glycans was observed throughout. Fc glycosylation changes were similar to results described before, with increased galactosylation and sialylation and decreased bisection during pregnancy. We expect that the parallel analysis of IgG Fab and Fc, as set up in this paper, will be important for unraveling roles of these glycans in (auto)immunity, which may be mediated via recognition by human lectins or modulation of antigen binding. PMID:25004930

A Hydraulically Operated Pine Cone Cutter

Treesearch

Carl W. Fatzinger; M.T. Proveaux

1971-01-01

Mature cones of slash pine (Pinus elliottii Engelm. var. elliottii) and longleaf pine (P. palustris Mill.) can be easily bisected along their longitudinal axes with the hydraulic pine cone cutter described. This cutter eliminates the two major problems of earlier models--undue operator fatigue and the...

The effect of mindfulness meditation on time perception.

PubMed

Kramer, Robin S S; Weger, Ulrich W; Sharma, Dinkar

2013-09-01

Research has increasingly focussed on the benefits of meditation in everyday life and performance. Mindfulness in particular improves attention, working memory capacity, and reading comprehension. Given its emphasis on moment-to-moment awareness, we hypothesised that mindfulness meditation would alter time perception. Using a within-subjects design, participants carried out a temporal bisection task, where several probe durations are compared to "short" and "long" standards. Following this, participants either listened to an audiobook or a meditation that focussed on the movement of breath in the body. Finally, participants completed the temporal bisection task for a second time. The control group showed no change after the listening task. However, meditation led to a relative overestimation of durations. Within an internal clock framework, a change in attentional resources can produce longer perceived durations. This meditative effect has wider implications for the use of mindfulness as an everyday practice and a basis for clinical treatment. Copyright © 2013 Elsevier Inc. All rights reserved.

System for maintaining the alignment of mandrels in filament winding operations

DOEpatents

Robinson, S.C.; Dodge, W.G.; Pollard, R.E.

1983-10-12

The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

System for maintaining the alignment of mandrels in filament winding operations

DOEpatents

Robinson, Samuel C.; Dodge, William G.; Pollard, Roy E.

1984-01-01

The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

The contribution of efficient production of monozygotic twins to beef cattle breeding

PubMed Central

HASHIYADA, Yutaka

2017-01-01

Production of sires with high breeding potential is indispensable for prompt and reliable breeding using their semen in the cattle industry. Currently, in Japan, we aim to further the production of Japanese black sires via a new breeding system that uses genetically homologous monozygotic twins so that better growth performance and carcass traits can be translated to the increased production of beef with higher economic value. Several studies have reported that monozygotic twins are produced by embryo bisection. On the other hand, with the evolution and stabilization of in vitro fertilization technology, it has become possible to produce multiple monozygotic twin calves from blastomeres separated from a cleavage-stage embryo. This review attempts to clarify breeding practices through revalidation of the factors that affect the production efficiency of monozygotic twin calves by embryo bisection. Furthermore, the establishment of a system for monozygotic twin embryo production via the simplified technique of blastomere separation is reviewed while showing data from our previously performed studies. PMID:29033399

NeuroLines: A Subway Map Metaphor for Visualizing Nanoscale Neuronal Connectivity.

PubMed

Al-Awami, Ali K; Beyer, Johanna; Strobelt, Hendrik; Kasthuri, Narayanan; Lichtman, Jeff W; Pfister, Hanspeter; Hadwiger, Markus

2014-12-01

We present NeuroLines, a novel visualization technique designed for scalable detailed analysis of neuronal connectivity at the nanoscale level. The topology of 3D brain tissue data is abstracted into a multi-scale, relative distance-preserving subway map visualization that allows domain scientists to conduct an interactive analysis of neurons and their connectivity. Nanoscale connectomics aims at reverse-engineering the wiring of the brain. Reconstructing and analyzing the detailed connectivity of neurons and neurites (axons, dendrites) will be crucial for understanding the brain and its development and diseases. However, the enormous scale and complexity of nanoscale neuronal connectivity pose big challenges to existing visualization techniques in terms of scalability. NeuroLines offers a scalable visualization framework that can interactively render thousands of neurites, and that supports the detailed analysis of neuronal structures and their connectivity. We describe and analyze the design of NeuroLines based on two real-world use-cases of our collaborators in developmental neuroscience, and investigate its scalability to large-scale neuronal connectivity data.

Visualizing and understanding vortex and tendex lines of colliding black holes

NASA Astrophysics Data System (ADS)

Khan, Haroon; Lovelace, Geoffery; Rodriguez, Samuel

2017-01-01

Gravitational waves (GWs) are ripples of spacetime. In order to detect and physically study the GW emitted by merging black holes with ground based detectors such as aLIGO, we must accurately predict how the waves look and behave. This requires numerical simulations of black hole (BH) mergers on supercomputers, because all analytical approximations fail near the time of merger. These simulations also reveal how BHs warp space and time. My project focuses on using these simulations to visualize the strongly curved space time in simulations of merging BHs. I have visualized the vortex and tendex lines for a binary BH system, using the Spectral Einstein Code. Vortex lines describe how an observer would be twisted by the curvature, and the tendex lines describe an observer would be stretched at squeezed by it. These lines are analogous to how electric and magnetic field lines describe the electromagnetic forces on an observer. Visualizing these will provide a more intuitive understanding of the nonlinear dynamics of the spacetime of merging BHs. I am exploring how these lines change with time during a simulation, to see whether they vary smoothly in time and how they depend on where they are seeded.

Drug/Cell-line Browser: interactive canvas visualization of cancer drug/cell-line viability assay datasets.

PubMed

Duan, Qiaonan; Wang, Zichen; Fernandez, Nicolas F; Rouillard, Andrew D; Tan, Christopher M; Benes, Cyril H; Ma'ayan, Avi

2014-11-15

Recently, several high profile studies collected cell viability data from panels of cancer cell lines treated with many drugs applied at different concentrations. Such drug sensitivity data for cancer cell lines provide suggestive treatments for different types and subtypes of cancer. Visualization of these datasets can reveal patterns that may not be obvious by examining the data without such efforts. Here we introduce Drug/Cell-line Browser (DCB), an online interactive HTML5 data visualization tool for interacting with three of the recently published datasets of cancer cell lines/drug-viability studies. DCB uses clustering and canvas visualization of the drugs and the cell lines, as well as a bar graph that summarizes drug effectiveness for the tissue of origin or the cancer subtypes for single or multiple drugs. DCB can help in understanding drug response patterns and prioritizing drug/cancer cell line interactions by tissue of origin or cancer subtype. DCB is an open source Web-based tool that is freely available at: http://www.maayanlab.net/LINCS/DCB CONTACT: avi.maayan@mssm.edu Supplementary data are available at Bioinformatics online. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

First Absolutely Calibrated Localized Measurements of Ion Velocity in the MST in Locked and Rotating Plasmas

NASA Astrophysics Data System (ADS)

Baltzer, M.; Craig, D.; den Hartog, D. J.; Nornberg, M. D.; Munaretto, S.

2015-11-01

An Ion Doppler Spectrometer (IDS) is used on MST for high time-resolution passive and active measurements of impurity ion emission. Absolutely calibrated measurements of flow are difficult because the spectrometer records data within 0.3 nm of the C+5 line of interest, and commercial calibration lamps do not produce lines in this narrow range . A novel optical system was designed to absolutely calibrate the IDS. The device uses an UV LED to produce a broad emission curve in the desired region. A Fabry-Perot etalon filters this light, cutting transmittance peaks into the pattern of the LED emission. An optical train of fused silica lenses focuses the light into the IDS with f/4. A holographic diffuser blurs the light cone to increase homogeneity. Using this light source, the absolute Doppler shift of ion emissions can be measured in MST plasmas. In combination with charge exchange recombination spectroscopy, localized ion velocities can now be measured. Previously, a time-averaged measurement along the chord bisecting the poloidal plane was used to calibrate the IDS; the quality of these central chord calibrations can be characterized with our absolute calibration. Calibration errors may also be quantified and minimized by optimizing the curve-fitting process. Preliminary measurements of toroidal velocity in locked and rotating plasmas will be shown. This work has been supported by the US DOE.

A visual resource management study of alternative dams, reservoirs and highway and transmission line corridors near Copper Creek, Washington

Treesearch

John Ady; Brian A. Gray; Grant R. Jones

1979-01-01

Three alternative dams have been considered by Seattle City Light for the Skagit River Narrows in the North Cascades National Recreation Area, Washington. The authors assessed the area's existing visual resources, identified three alternative highway and transmission line realignments, evaluated changes in visual character and quality for 13 different combinations...

Dental Radiology I Student Guide [and Instructor Guide].

ERIC Educational Resources Information Center

Fox Valley Technical Coll., Appleton, WI.

The dental radiology student and instructor guides provide instruction in the following units: (1) x-ray physics; (2) x-ray production; (3) radiation health and safety; (4) radiographic anatomy and pathology; (5) darkroom setup and chemistry; (6) bisecting angle technique; (7) paralleling technique; (8) full mouth survey technique--composition and…

Updating of visual orientation in a gravity-based reference frame.

PubMed

Niehof, Nynke; Tramper, Julian J; Doeller, Christian F; Medendorp, W Pieter

2017-10-01

The brain can use multiple reference frames to code line orientation, including head-, object-, and gravity-centered references. If these frames change orientation, their representations must be updated to keep register with actual line orientation. We tested this internal updating during head rotation in roll, exploiting the rod-and-frame effect: The illusory tilt of a vertical line surrounded by a tilted visual frame. If line orientation is stored relative to gravity, these distortions should also affect the updating process. Alternatively, if coding is head- or frame-centered, updating errors should be related to the changes in their orientation. Ten subjects were instructed to memorize the orientation of a briefly flashed line, surrounded by a tilted visual frame, then rotate their head, and subsequently judge the orientation of a second line relative to the memorized first while the frame was upright. Results showed that updating errors were mostly related to the amount of subjective distortion of gravity at both the initial and final head orientation, rather than to the amount of intervening head rotation. In some subjects, a smaller part of the updating error was also related to the change of visual frame orientation. We conclude that the brain relies primarily on a gravity-based reference to remember line orientation during head roll.

Parametric study of beam refraction problems across laser anemometer windows

NASA Technical Reports Server (NTRS)

Owen, A. K.

1986-01-01

The experimenter is often required to view flows through a window with a different index of refraction than either the medium being observed or the medium that the laser anemometer is immersed in. The refraction that occurs at the window surfaces may lead to undesirable changes in probe volume position or beam crossing angle and can lead to partial or complete beam uncrossing. This report describes the results of a parametric study of this problem using a ray tracing technique to predict these changes. The windows studied were a flat plate and a simple cyclinder. For the flat-plate study: (1) surface thickness, (2) beam crossing angle, (3) bisecting line - surface normal angle, and (4) incoming beam plane surface orientation were varied. For the cylindrical window additional parameters were also varied: (1) probe volume immersion, (2) probe volume off-radial position, and (3) probe volume position out of the R-theta plane of the lens. A number of empirical correlations were deduced to aid the interested reader in determining the movement, uncrossing, and change in crossing angle for a particular situation.

A parametric study of the beam refraction problems across laser anemometer windows

NASA Technical Reports Server (NTRS)

Owen, Albert K.

1986-01-01

The experimenter is often required to view flows through a window with a different index of refraction than either the medium being observed or the medium that the laser anemometer is immersed in. The refraction that occurs at the window surfaces may lead to undesirable changes in probe volume position or beam crossing angle and can lead to partial or complete beam uncrossing. This report describes the results of a parametric study of this problem using a ray tracing technique to predict these changes. The windows studied were a flat plate and a simple cylinder. For the flat-plate study: (1) surface thickness, (2) beam crossing angle, (3) bisecting line - surface normal angle, and (4) incoming beam plane surface orientation were varied. For the cylindrical window additional parameters were also varied: (1) probe volume immersion, (2) probe volume off-radial position, and (3) probe volume position out of the r-theta plane of the lens. A number of empirical correlations were deduced to aid the reader in determining the movement, uncrossing, and change in crossing angle for a particular situations.

An Intrinsic Role of Beta Oscillations in Memory for Time Estimation.

PubMed

Wiener, Martin; Parikh, Alomi; Krakow, Arielle; Coslett, H Branch

2018-05-22

The neural mechanisms underlying time perception are of vital importance to a comprehensive understanding of behavior and cognition. Recent work has suggested a supramodal role for beta oscillations in measuring temporal intervals. However, the precise function of beta oscillations and whether their manipulation alters timing has yet to be determined. To accomplish this, we first re-analyzed two, separate EEG datasets and demonstrate that beta oscillations are associated with the retention and comparison of a memory standard for duration. We next conducted a study of 20 human participants using transcranial alternating current stimulation (tACS), over frontocentral cortex, at alpha and beta frequencies, during a visual temporal bisection task, finding that beta stimulation exclusively shifts the perception of time such that stimuli are reported as longer in duration. Finally, we decomposed trialwise choice data with a drift diffusion model of timing, revealing that the shift in timing is caused by a change in the starting point of accumulation, rather than the drift rate or threshold. Our results provide evidence for the intrinsic involvement of beta oscillations in the perception of time, and point to a specific role for beta oscillations in the encoding and retention of memory for temporal intervals.

The extent of visual space inferred from perspective angles

PubMed Central

Erkelens, Casper J.

2015-01-01

Retinal images are perspective projections of the visual environment. Perspective projections do not explain why we perceive perspective in 3-D space. Analysis of underlying spatial transformations shows that visual space is a perspective transformation of physical space if parallel lines in physical space vanish at finite distance in visual space. Perspective angles, i.e., the angle perceived between parallel lines in physical space, were estimated for rails of a straight railway track. Perspective angles were also estimated from pictures taken from the same point of view. Perspective angles between rails ranged from 27% to 83% of their angular size in the retinal image. Perspective angles prescribe the distance of vanishing points of visual space. All computed distances were shorter than 6 m. The shallow depth of a hypothetical space inferred from perspective angles does not match the depth of visual space, as it is perceived. Incongruity between the perceived shape of a railway line on the one hand and the experienced ratio between width and length of the line on the other hand is huge, but apparently so unobtrusive that it has remained unnoticed. The incompatibility between perspective angles and perceived distances casts doubt on evidence for a curved visual space that has been presented in the literature and was obtained from combining judgments of distances and angles with physical positions. PMID:26034567

IDEN2-A program for visual identification of spectral lines and energy levels in optical spectra of atoms and simple molecules

NASA Astrophysics Data System (ADS)

Azarov, V. I.; Kramida, A.; Vokhmentsev, M. Ya.

2018-04-01

The article describes a Java program that can be used in a user-friendly way to visually identify spectral lines observed in complex spectra with theoretically predicted transitions between atomic or molecular energy levels. The program arranges various information about spectral lines and energy levels in such a way that line identification and determination of positions of experimentally observed energy levels become much easier tasks that can be solved fast and efficiently.

Using Time Perception to Explore Implicit Sensitivity to Emotional Stimuli in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Jones, Catherine R. G.; Lambrechts, Anna; Gaigg, Sebastian B.

2017-01-01

Establishing whether implicit responses to emotional cues are intact in autism spectrum disorder (ASD) is fundamental to ascertaining why their emotional understanding is compromised. We used a temporal bisection task to assess for responsiveness to face and wildlife images that varied in emotional salience. There were no significant differences…

49 CFR 571.221 - Standard No. 221; School bus body joint strength.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and any structure forward of the passenger compartment. Maintenance access panel means a body panel... so that it does not bisect a spot weld or a discrete fastener. Support members which contribute to... structure attached to joint members, shall remain attached to the test specimen, except that material may be...

49 CFR 571.221 - Standard No. 221; School bus body joint strength.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and any structure forward of the passenger compartment. Maintenance access panel means a body panel... so that it does not bisect a spot weld or a discrete fastener. Support members which contribute to... structure attached to joint members, shall remain attached to the test specimen, except that material may be...

49 CFR 571.221 - Standard No. 221; School bus body joint strength.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and any structure forward of the passenger compartment. Maintenance access panel means a body panel... so that it does not bisect a spot weld or a discrete fastener. Support members which contribute to... structure attached to joint members, shall remain attached to the test specimen, except that material may be...

49 CFR 571.221 - Standard No. 221; School bus body joint strength.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and any structure forward of the passenger compartment. Maintenance access panel means a body panel... so that it does not bisect a spot weld or a discrete fastener. Support members which contribute to... structure attached to joint members, shall remain attached to the test specimen, except that material may be...

49 CFR 571.221 - Standard No. 221; School bus body joint strength.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and any structure forward of the passenger compartment. Maintenance access panel means a body panel... so that it does not bisect a spot weld or a discrete fastener. Support members which contribute to... structure attached to joint members, shall remain attached to the test specimen, except that material may be...

Interval-Timing Deficits in Individuals at High Risk for Schizophrenia

ERIC Educational Resources Information Center

Penney, T.B.; Meck, W.H.; Roberts, S.A.; Gibbon, J.; Erlenmeyer-Kimling, L.

2005-01-01

A duration-bisection procedure was used to study the effects of signal modality and divided attention on duration classification in participants at high genetic risk for schizophrenia (HrSz), major affective disorder (HrAff), and normal controls (NC). Participants learned short and long target durations during training and classified probe…

Psychophysical Assessment of Timing in Individuals with Autism

ERIC Educational Resources Information Center

Allman, Melissa J.; DeLeon, Iser G.

2011-01-01

Perception of time, in the seconds to minutes range, is not well characterized in autism. The required interval timing system (ITS) develops at the same stages during infancy as communication, social reciprocity, and other cognitive and behavioral functions. The authors used two versions of a temporal bisection procedure to study the perception of…

Numerosity Discrimination in Preschool Children

ERIC Educational Resources Information Center

Almeida, Alzira; Arantes, Joana; Machado, Armando

2007-01-01

We used a numerical bisection procedure to examine preschool children's sensitivity to the numerical attributes of stimuli. In Experiment 1 children performed two tasks. In the Cups Task they earned coins for choosing a green cup after two drumbeats and a blue cup after eight drumbeats. In the Gloves Task they earned coins for raising a red glove…

Microfluidic guillotine for single-cell wound repair studies

NASA Astrophysics Data System (ADS)

Blauch, Lucas R.; Gai, Ya; Khor, Jian Wei; Sood, Pranidhi; Marshall, Wallace F.; Tang, Sindy K. Y.

2017-07-01

Wound repair is a key feature distinguishing living from nonliving matter. Single cells are increasingly recognized to be capable of healing wounds. The lack of reproducible, high-throughput wounding methods has hindered single-cell wound repair studies. This work describes a microfluidic guillotine for bisecting single Stentor coeruleus cells in a continuous-flow manner. Stentor is used as a model due to its robust repair capacity and the ability to perform gene knockdown in a high-throughput manner. Local cutting dynamics reveals two regimes under which cells are bisected, one at low viscous stress where cells are cut with small membrane ruptures and high viability and one at high viscous stress where cells are cut with extended membrane ruptures and decreased viability. A cutting throughput up to 64 cells per minute—more than 200 times faster than current methods—is achieved. The method allows the generation of more than 100 cells in a synchronized stage of their repair process. This capacity, combined with high-throughput gene knockdown in Stentor, enables time-course mechanistic studies impossible with current wounding methods.

A navigation system for the visually impaired using colored navigation lines and RFID tags.

PubMed

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.

Sedentary behavior as a factor in determining lateral line contributions to rheotaxis.

PubMed

Bak-Coleman, Joseph; Coombs, Sheryl

2014-07-01

Rheotaxis is a robust, multisensory behavior with many potential benefits for fish and other aquatic animals. Visual (optic flow) cues appear to be sufficient for rheotaxis, but other sensory cues can clearly compensate for the loss of vision. The role of various non-visual sensory systems, in particular the flow-sensing lateral line, is poorly understood, largely because of widely varying methods and sensory conditions for studying rheotaxis. Here, we examine how sedentary behavior under visually deprived conditions affects the relative importance of lateral line cues in two species: one that is normally sedentary (the three-lined corydoras, Corydoras trilineatus) and one that normally swims continuously along the substrate (the blind cavefish, Astyanax mexicanus). No effect of lateral line disruption on rheotactic performance was found in blind cavefish, which were significantly more mobile than three-lined corydoras. By contrast, rheotaxis was significantly impaired at low, but not high, flow speeds in lateral-line-disabled corydoras. In addition, lateral-line-enabled corydoras were characterized by decreased mobility and increased rheotactic performance relative to lateral-line-disabled fish. Taken together, these results suggest that sedentary behavior is an important factor in promoting reliance on lateral line cues. © 2014. Published by The Company of Biologists Ltd.

Temporal Visualization for Legal Case Histories.

ERIC Educational Resources Information Center

Harris, Chanda; Allen, Robert B.; Plaisant, Catherine; Shneiderman, Ben

1999-01-01

Discusses visualization of legal information using a tool for temporal information called "LifeLines." Explores ways "LifeLines" could aid in viewing the links between original case and direct and indirect case histories. Uses the case of Apple Computer, Inc. versus Microsoft Corporation and Hewlett Packard Company to…

A Randomized Trial Comparing Bangerter Filters and Patching for the Treatment of Moderate Amblyopia in Children

PubMed Central

2009-01-01

Objective To determine whether visual acuity improvement with Bangerter filters is similar to improvement with patching as initial therapy for children with moderate amblyopia. Design Randomized clinical trial. Participants 186 children, 3 to <10 years old, with moderate amblyopia (20/40 to 20/80). Methods Children were randomly assigned to receive either daily patching or to use a Bangerter filter on the spectacle lens in front of the fellow eye. Study visits were scheduled at 6, 12, 18 and 24 weeks. Main outcome measure Visual acuity in amblyopic eye at 24 weeks. Results At 24 weeks, amblyopic eye improvement averaged 1.9 lines in the Bangerter group and 2.3 lines in the patching group (difference in mean visual acuities between groups adjusted for baseline acuity = 0.38 line). The upper limit of a 1-sided 95% confidence interval was 0.76 line, which slightly exceeded a pre-specified non-inferiority limit of < 0.75 line. Similar percentages of subjects in each group improved ≥3 lines (Bangerter group 38% versus patching group 35%, P=0.61) or had 20/25 or better amblyopic eye acuity (36% versus 31%, respectively, P=0.86). There was a lower treatment burden in the Bangerter group as measured with the Amblyopia Treatment Index. With Bangerter filters, neither a fixation switch to the amblyopic eye nor induced blurring in the fellow eye to worse than that of the amblyopic eye was required for visual acuity improvement. Conclusion Because the average difference in visual acuity improvement between Bangerter filters and patching was less than half a line, and there was lower burden of treatment on the child and family, Bangerter filter treatment is a reasonable option to consider for initial treatment of moderate amblyopia. PMID:20163869

Implementation of an oblique-sectioning visualization tool for line-of-sight stereotactic neurosurgical navigation using the AVW toolkit

NASA Astrophysics Data System (ADS)

Bates, Lisa M.; Hanson, Dennis P.; Kall, Bruce A.; Meyer, Frederic B.; Robb, Richard A.

1998-06-01

An important clinical application of biomedical imaging and visualization techniques is provision of image guided neurosurgical planning and navigation techniques using interactive computer display systems in the operating room. Current systems provide interactive display of orthogonal images and 3D surface or volume renderings integrated with and guided by the location of a surgical probe. However, structures in the 'line-of-sight' path which lead to the surgical target cannot be directly visualized, presenting difficulty in obtaining full understanding of the 3D volumetric anatomic relationships necessary for effective neurosurgical navigation below the cortical surface. Complex vascular relationships and histologic boundaries like those found in artereovenous malformations (AVM's) also contribute to the difficulty in determining optimal approaches prior to actual surgical intervention. These difficulties demonstrate the need for interactive oblique imaging methods to provide 'line-of-sight' visualization. Capabilities for 'line-of- sight' interactive oblique sectioning are present in several current neurosurgical navigation systems. However, our implementation is novel, in that it utilizes a completely independent software toolkit, AVW (A Visualization Workshop) developed at the Mayo Biomedical Imaging Resource, integrated with a current neurosurgical navigation system, the COMPASS stereotactic system at Mayo Foundation. The toolkit is a comprehensive, C-callable imaging toolkit containing over 500 optimized imaging functions and structures. The powerful functionality and versatility of the AVW imaging toolkit provided facile integration and implementation of desired interactive oblique sectioning using a finite set of functions. The implementation of the AVW-based code resulted in higher-level functions for complete 'line-of-sight' visualization.

Visual Survey of Infantry Troops. Part 1. Visual Acuity, Refractive Status, Interpupillary Distance and Visual Skills

DTIC Science & Technology

1989-06-01

letters on one line and several letters on the next line, there is no accurate way to credit these extra letters for statistical analysis. The decimal and...contains the descriptive statistics of the objective refractive error components of infantrymen. Figures 8-11 show the frequency distributions for sphere...equivalents. Nonspectacle wearers Table 12 contains the idescriptive statistics for non- spectacle wearers. Based or these refractive error data, about 30

42. Photocopy of photograph (original photograph in possession of Sacramento ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. Photocopy of photograph (original photograph in possession of Sacramento Archives and Museum Collection Center, Sacramento, California) Original photographer and year unknown. BEANS GROWING ON THE PHILIP S. DRIVER ESTATE LANDS IN NATOMAS DISTRICT NO. 1000. - Reclamation District 1000, Northwest Sacramento County & southwest Sutter County, bisected by State Highway No. 99, Sacramento, Sacramento County, CA

Time Perception in Children Treated for a Cerebellar Medulloblastoma

ERIC Educational Resources Information Center

Droit-Volet, Sylvie; Zelanti, Pierre S.; Dellatolas, Georges; Kieffer, Virginie; El Massioui, Nicole; Brown, Bruce L.; Doyere, Valerie; Provasi, Joelle; Grill, Jacques

2013-01-01

The aim of the present study was to investigate temporal abilities in children treated by surgery for a malignant tumor in the cerebellum. Children with a diagnosed medulloblastoma and age-paired control children were given a temporal discrimination task (bisection task) and a temporal reproduction task with two duration ranges, one shorter than 1…

Small mammal distributions relative to corridor edges within intensively managed southern pine plantations.

Treesearch

Nicole L. Constantine; Tyler A. Campbell; William M. Baughman; Timothy B. Harrington; Brian R. Chapman; Karl V. Miller

2005-01-01

We characterized small mammal communities in three loblolly pine (Pinus taeda) stands in the Lower Coastal Plain of South Carolina during June 1998-Aug. 2000 to investigate influence of corridor edges on small mammal distribution. We live-trapped small mammals in three regenerating stands following clearcutting. Harvested stands were bisected by...

An Integrated Theory of Prospective Time Interval Estimation: The Role of Cognition, Attention, and Learning

ERIC Educational Resources Information Center

Taatgen, Niels A.; van Rijn, Hedderik; Anderson, John

2007-01-01

A theory of prospective time perception is introduced and incorporated as a module in an integrated theory of cognition, thereby extending existing theories and allowing predictions about attention and learning. First, a time perception module is established by fitting existing datasets (interval estimation and bisection and impact of secondary…

Dynamics of Folds in the Plane

ERIC Educational Resources Information Center

Krylov, Nikolai A.; Rogers, Edwin L.

2011-01-01

Take a strip of paper and fold a crease intersecting the long edges, creating two angles. Choose one edge and consider the angle with the crease. Fold the opposite edge along the crease, creating a new crease that bisects the angle. Fold again, this time using the newly created crease and the initial edge, creating a new angle along the chosen…

A single peptide loop in an alpha-Helix

USDA-ARS?s Scientific Manuscript database

Pitch is not a height but a ratio of rise/run. In an alpha-helix, run can be as the radius (r) from the center of the circle, as a diameter (d) measured across/bisecting a circumference, or as a distance (c) along a circumference; rise in each case can corresponds to same height (h) increase. For ...

SOFIA Observations of S106: Dynamics of the Warm Gas

NASA Technical Reports Server (NTRS)

Simon, R.; Schneider, N.; Stutzki, J.; Gusten, R.; Graf, U. U.; Hartogh, P.; Guan, X.; Staguhn, J. G.; Benford, D. J.

2012-01-01

Context The H II region/PDR/molecular cloud complex S106 is excited by a single O-star. The full extent of the warm and dense gas close to the star has not been mapped in spectrally resolved high-J CO or [C II] lines, so the kinematics of the warm. partially ionized gas, are unknown. Whether the prominent dark lane bisecting the hourglass-shaped nebula is due solely to the shadow cast by a small disk around the exciting star or also to extinction in high column foreground gas was an open question until now. Aims. To disentangle the morphology and kinematics of warm neutral and ionized gas close to the star, study their relation to the bulk of the molecular gas. and to investigate the nature of the dark lane. Methods. We use the heterodyne receiver GREAT on board SOFIA to observe velocity resolved spectral lines of [C II] and CO 11 yields 10 in comparison with so far unpublished submm continuum data at 350 micron (8HARC-Il) and complementary molecular line data. Results. The high angular and spectral resolution observations show a very complex morphology and kinematics of the inner S106 region, with many different components at different excitation conditions contributing to the observed emission. The [C II] lines are found to be bright and very broad. tracing high velocity gas close to the interface of molecular cloud and H II region. CO 11 yields 10 emission is more confined.. both spatially and in velocity, to the immediate surroundings of S 106 IR showing the presence of warm, high density (clumpy) gas. Our high angular resolution submm continuum observations rule out the scenario where the dark lane separating the two lobes is due solely to the shadow cast by a small disk close to the star. The lane is clearly seen also as warm, high column density gas at the boundary of the molecular cloud and H II region.

Measuring the effect of multiple eye fixations on memory for visual attributes.

PubMed

Palmer, J; Ames, C T

1992-09-01

Because of limited peripheral vision, many visual tasks depend on multiple eye fixations. Good performance in such tasks demonstrates that some memory must survive from one fixation to the next. One factor that must influence performance is the degree to which multiple eye fixations interfere with the critical memories. In the present study, the amount of interference was measured by comparing visual discriminations based on multiple fixations to visual discriminations based on a single fixation. The procedure resembled partial report, but used a discrimination measure. In the prototype study, two lines were presented, followed by a single line and a cue. The cue pointed toward one of the positions of the first two lines. Observers were required to judge if the single line in the second display was longer or shorter than the cued line of the first display. These judgments were used to estimate a length threshold. The critical manipulation was to instruct observers either to maintain fixation between the lines of the first display or to fixate each line in sequence. The results showed an advantage for multiple fixations despite the intervening eye movements. In fact, thresholds for the multiple-fixation condition were nearly as good as those in a control condition where the lines were foveally viewed without eye movements. Thus, eye movements had little or no interfering effect in this task. Additional studies generalized the procedure and the stimuli. In conclusion, information about a variety of size and shape attributes was remembered with essentially no interference across eye fixations.

Heuristics of reasoning and analogy in children's visual perspective taking.

PubMed

Yaniv, I; Shatz, M

1990-10-01

We propose that children's reasoning about others' visual perspectives is guided by simple heuristics based on a perceiver's line of sight and salient features of the object met by that line. In 3 experiments employing a 2-perceiver analogy task, children aged 3-6 were generally better able to reproduce a perceiver's perspective if a visual cue in the perceiver's line of sight sufficed to distinguish it from alternatives. Children had greater difficulty when the task hinged on attending to configural cues. Availability of distinctive cues affixed on the objects' sides facilitated solution of the symmetrical orientations. These and several other related findings reported in the literature are traced to children's reliance on heuristics of reasoning.

Combined influences of gravitoinertial force level and visual field pitch on visually perceived eye level

NASA Technical Reports Server (NTRS)

DiZio, P.; Li, W.; Lackner, J. R.; Matin, L.

1997-01-01

Psychophysical measurements of the level at which observers set a small visual target so as to appear at eye level (VPEL) were made on 13 subjects in 1.0 g and 1.5 g environments in the Graybiel Laboratory rotating room while they viewed a pitched visual field or while in total darkness. The gravitoinertial force was parallel to the z-axis of the head and body during the measurements. The visual field consisted of two 58 degrees high, luminous, pitched-from-vertical, bilaterally symmetric, parallel lines, viewed in otherwise total darkness. The lines were horizontally separated by 53 degrees and presented at each of 7 angles of pitch ranging from 30 degrees with the top of the visual field turned away from the subject (top backward) to 30 degrees with the top turned toward the subject (top forward). At 1.5 g, VPEL changed linearly with the pitch of the 2-line stimulus and was depressed with top backward pitch and elevated with top forward pitch as had been reported previously at 1.0 g (1,2); however, the slopes of the VPEL-vs-pitch functions at 1.0 g and 1.5 g were indistinguishable. As reported previously also (3,4), the VPEL in darkness was considerably lower at 1.5 g than at 1.0 g; however, although the y-intercept of the VPEL-vs-pitch function in the presence of the 2-line visual field (visual field erect) was also lower at 1.5 g than at 1.0 g as it was in darkness, the G-related difference was significantly attenuated by the presence of the visual field. The quantitative characteristics of the results are consistent with a model in which VPEL is treated as a consequence of an algebraic weighted average or a vector sum of visual and nonvisual influences although the two combining rules lead to fits that are equally good.

CRITIC2: A program for real-space analysis of quantum chemical interactions in solids

NASA Astrophysics Data System (ADS)

Otero-de-la-Roza, A.; Johnson, Erin R.; Luaña, Víctor

2014-03-01

We present CRITIC2, a program for the analysis of quantum-mechanical atomic and molecular interactions in periodic solids. This code, a greatly improved version of the previous CRITIC program (Otero-de-la Roza et al., 2009), can: (i) find critical points of the electron density and related scalar fields such as the electron localization function (ELF), Laplacian, … (ii) integrate atomic properties in the framework of Bader’s Atoms-in-Molecules theory (QTAIM), (iii) visualize non-covalent interactions in crystals using the non-covalent interactions (NCI) index, (iv) generate relevant graphical representations including lines, planes, gradient paths, contour plots, atomic basins, … and (v) perform transformations between file formats describing scalar fields and crystal structures. CRITIC2 can interface with the output produced by a variety of electronic structure programs including WIEN2k, elk, PI, abinit, Quantum ESPRESSO, VASP, Gaussian, and, in general, any other code capable of writing the scalar field under study to a three-dimensional grid. CRITIC2 is parallelized, completely documented (including illustrative test cases) and publicly available under the GNU General Public License. Catalogue identifier: AECB_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AECB_v2_0.html Program obtainable from: CPC Program Library, Queen’s University, Belfast, N. Ireland Licensing provisions: yes No. of lines in distributed program, including test data, etc.: 11686949 No. of bytes in distributed program, including test data, etc.: 337020731 Distribution format: tar.gz Programming language: Fortran 77 and 90. Computer: Workstations. Operating system: Unix, GNU/Linux. Has the code been vectorized or parallelized?: Shared-memory parallelization can be used for most tasks. Classification: 7.3. Catalogue identifier of previous version: AECB_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 157 Nature of problem: Analysis of quantum-chemical interactions in periodic solids by means of atoms-in-molecules and related formalisms. Solution method: Critical point search using Newton’s algorithm, atomic basin integration using bisection, qtree and grid-based algorithms, diverse graphical representations and computation of the non-covalent interactions index on a three-dimensional grid. Additional comments: !!!!! The distribution file for this program is over 330 Mbytes and therefore is not delivered directly when download or Email is requested. Instead a html file giving details of how the program can be obtained is sent. !!!!! Running time: Variable, depending on the crystal and the source of the underlying scalar field.

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets

PubMed Central

Bola, Łukasz; Radziun, Dominika; Siuda-Krzywicka, Katarzyna; Sowa, Joanna E.; Paplińska, Małgorzata; Sumera, Ewa; Szwed, Marcin

2017-01-01

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a “normal” script (e.g., Cyrillic). Using a lexical decision task, we examined Visual Braille reading speed and efficiency in sighted Braille teachers. As a control, we tested learners of a natural visual script, Cyrillic. Both groups participated in a two semester course of either visual Braille or Russian while their reading speed and accuracy was tested at regular intervals. The results show that visual Braille reading is slow, prone to errors and highly serial, even in Braille readers with years of prior reading experience. Although subjects showed some improvements in their visual Braille reading accuracy and speed following the course, the effect of word length on reading speed (typically observed in beginning readers) was remained very sizeable through all testing sessions. These results are in stark contrast to Cyrillic, a natural script, where only 3 months of learning were sufficient to achieve relative proficiency. Taken together, these results suggest that visual features such as line junctions and their combinations might be necessary for efficient reading. PMID:28421027

Universal Visual Features Might Be Necessary for Fluent Reading. A Longitudinal Study of Visual Reading in Braille and Cyrillic Alphabets.

PubMed

Bola, Łukasz; Radziun, Dominika; Siuda-Krzywicka, Katarzyna; Sowa, Joanna E; Paplińska, Małgorzata; Sumera, Ewa; Szwed, Marcin

2017-01-01

It has been hypothesized that efficient reading is possible because all reading scripts have been matched, through cultural evolution, to the natural capabilities of the visual cortex. This matching has resulted in all scripts being made of line-junctions, such as T, X, or L. Our aim was to test a critical prediction of this hypothesis: visual reading in an atypical script that is devoid of line-junctions (such as the Braille alphabet read visually) should be much less efficient than reading in a "normal" script (e.g., Cyrillic). Using a lexical decision task, we examined Visual Braille reading speed and efficiency in sighted Braille teachers. As a control, we tested learners of a natural visual script, Cyrillic. Both groups participated in a two semester course of either visual Braille or Russian while their reading speed and accuracy was tested at regular intervals. The results show that visual Braille reading is slow, prone to errors and highly serial, even in Braille readers with years of prior reading experience. Although subjects showed some improvements in their visual Braille reading accuracy and speed following the course, the effect of word length on reading speed (typically observed in beginning readers) was remained very sizeable through all testing sessions. These results are in stark contrast to Cyrillic, a natural script, where only 3 months of learning were sufficient to achieve relative proficiency. Taken together, these results suggest that visual features such as line junctions and their combinations might be necessary for efficient reading.

Visual and visually mediated haptic illusions with Titchener's ⊥.

PubMed

Landwehr, Klaus

2014-05-01

For a replication and expansion of a previous experiment of mine, 14 newly recruited participants provided haptic and verbal estimates of the lengths of the two lines that make up Titchener's ⊥. The stimulus was presented at two different orientations (frontoparallel vs. horizontal) and rotated in steps of 45 deg around 2π. Haptically, the divided line of the ⊥ was generally underestimated, especially at a horizontal orientation. Verbal judgments also differed according to presentation condition and to which line was the target, with the overestimation of the undivided line ranging between 6.2 % and 15.3 %. The results are discussed with reference to the two-visual-systems theory of perception and action, neuroscientific accounts, and also recent historical developments (the use of handheld touchscreens, in particular), because the previously reported "haptic induction effect" (the scaling of haptic responses to the divided line of the ⊥, depending on the length of the undivided one) did not replicate.

Line Spread as a Visual Clinical Tool for Thickened Liquids

ERIC Educational Resources Information Center

Lund, Annelise Masters; Mertz Garcia, Jane; Chambers, Edgar, IV.

2013-01-01

Purpose: Preparing modified liquids to a target level of consistency is critical to patients' nutritional care. This study examined the relationship of line spread (i.e., the distance a liquid flows) to viscometer measurements for a variety of product/liquid combinations and determined if flow distance visually differentiated nectar-thick…

Visualizing Time-Varying Phenomena In Numerical Simulations Of Unsteady Flows

NASA Technical Reports Server (NTRS)

Lane, David A.

1996-01-01

Streamlines, contour lines, vector plots, and volume slices (cutting planes) are commonly used for flow visualization. These techniques are sometimes referred to as instantaneous flow visualization techniques because calculations are based on an instant of the flowfield in time. Although instantaneous flow visualization techniques are effective for depicting phenomena in steady flows,they sometimes do not adequately depict time-varying phenomena in unsteady flows. Streaklines and timelines are effective visualization techniques for depicting vortex shedding, vortex breakdown, and shock waves in unsteady flows. These techniques are examples of time-dependent flow visualization techniques, which are based on many instants of the flowfields in time. This paper describes the algorithms for computing streaklines and timelines. Using numerically simulated unsteady flows, streaklines and timelines are compared with streamlines, contour lines, and vector plots. It is shown that streaklines and timelines reveal vortex shedding and vortex breakdown more clearly than instantaneous flow visualization techniques.

Visual perceptual load induces inattentional deafness.

PubMed

Macdonald, James S P; Lavie, Nilli

2011-08-01

In this article, we establish a new phenomenon of "inattentional deafness" and highlight the level of load on visual attention as a critical determinant of this phenomenon. In three experiments, we modified an inattentional blindness paradigm to assess inattentional deafness. Participants made either a low- or high-load visual discrimination concerning a cross shape (respectively, a discrimination of line color or of line length with a subtle length difference). A brief pure tone was presented simultaneously with the visual task display on a final trial. Failures to notice the presence of this tone (i.e., inattentional deafness) reached a rate of 79% in the high-visual-load condition, significantly more than in the low-load condition. These findings establish the phenomenon of inattentional deafness under visual load, thereby extending the load theory of attention (e.g., Lavie, Journal of Experimental Psychology. Human Perception and Performance, 25, 596-616, 1995) to address the cross-modal effects of visual perceptual load.

Improvement of visual acuity by refraction in a low-vision population.

PubMed

Sunness, Janet S; El Annan, Jaafar

2010-07-01

Refraction often may be overlooked in low-vision patients, because the main cause of vision decrease is not refractive, but rather is the result of underlying ocular disease. This retrospective study was carried out to determine how frequently and to what extent visual acuity is improved by refraction in a low-vision population. Cross-sectional study. Seven hundred thirty-nine low-vision patients seen for the first time. A database with all new low-vision patients seen from November 2005 through June 2008 recorded presenting visual acuity using an Early Treatment Diabetic Retinopathy Study chart; it also recorded the best-corrected visual acuity (BCVA) if it was 2 lines or more better than the presenting visual acuity. Retinoscopy was carried out on all patients, followed by manifest refraction. Improvement in visual acuity. Median presenting acuity was 20/80(-2) (interquartile range, 20/50-20/200). There was an improvement of 2 lines or more of visual acuity in 81 patients (11% of all patients), with 22 patients (3% of all patients) improving by 4 lines or more. There was no significant difference in age or in presenting visual acuity between the group that did not improve by refraction and the group that did improve. When stratified by diagnosis, the only 2 diagnoses with a significantly higher rate of improvement than the age-related macular degeneration group were myopic degeneration and progressive myopia (odds ratio, 4.8; 95% confidence interval [CI], 3.0-6.7) and status post-retinal detachment (odds ratio, 7.1; 95% CI, 5.2-9.0). For 5 patients (6% of those with improvement), the eye that was 1 line or more worse than the fellow eye at presentation became the eye that was 1 line or more better than the fellow eye after refraction. A significant improvement in visual acuity was attained by refraction in 11% of the new low-vision patients. Improvement was seen across diagnoses and the range of presenting visual acuity. The worse-seeing eye at presentation may become the better-seeing eye after refraction, so that the eye behind a balance lens should be refracted as well. Proprietary or commercial disclosure may be found after the references. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Distance versus near visual acuity in amblyopia

PubMed Central

Christoff, Alex; Repka, Michael X.; Kaminski, Brett M.; Holmes, Jonathan M.; Ch, B

2011-01-01

Purpose There are conflicting reports about whether distance and near visual acuity are similar in eyes with amblyopia. The purpose of this study is to compare monocular distance visual acuity with near visual acuity in amblyopic eyes of children. Methods Subjects 2 to 6 years of age were evaluated in a randomized trial of amblyopia therapy for moderate amblyopia (20/40 to 20/80) due to anisometropia, strabismus, or both. Prior to initiating the protocol-prescribed therapy, subjects had best-corrected visual acuity measured with standardized protocols at 3 meters and 0.4 meters using single-surrounded HOTV optotypes. Results A total of 129 subjects were included. The mean amblyopic eye visual acuity was similar at distance and near (mean, 0.45 logMAR at distance versus 0.45 logMAR at near; mean difference, +0.00, 95% CI, −0.03 to 0.03). Of the 129 subjects, 86 (67%) tested within one line at distance and near, 19 (15%) tested more than one logMAR line better at distance, and 24 (19%) tested more than one logMAR line better at near. The mean visual acuity difference between distance and near did not differ by cause of amblyopia, age, or spherical equivalent refractive error. Conclusions We found no systematic difference between distance and near visual acuity in 2- to 6-year-old children with moderate amblyopia associated with strabismus and/or anisometropia. Individual differences between distance and near visual acuity are likely due to test–retest variability. PMID:21907115

Power line detection system

DOEpatents

Latorre, Victor R.; Watwood, Donald B.

1994-01-01

A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard.

Ecological investigations to select mitigation options to reduce vehicle-caused mortality of a threatened butterfly

Treesearch

Sara B. Zielin; Jalene Littlejohn; Catherine E. de Rivera; Winston P. Smith; Sandra L. Jacobson

2016-01-01

Whereas roads that bisect habitat are known to decrease population size through animal-vehicle collisions or interruption of key life history events, it is not always obvious how to reduce such impacts, especially for flying organisms. We needed a quick, cost-efficient and effective way to determine how best to decrease vehicle-caused mortality while maintaining...

Mapping and assessing the environmental impacts of border tactical infrastructure in the Sky Island Region

Treesearch

Caroline Patrick-Birdwell; Sergio Avila-Villegas; Jenny Neeley; Louise Misztal

2013-01-01

In this project we mapped the different types of border barriers, identified impacts of border infrastructure on public and private lands and conducted spatial analyses within the approximately 200 miles of international border in the Sky Island region. The Sky Island region, bisected by the U.S.-Mexico border, is critically important for its biodiversity and...

The Interaction of Temporal Generalization Gradients Predicts the Context Effect

ERIC Educational Resources Information Center

de Castro, Ana Catarina; Machado, Armando

2012-01-01

In a temporal double bisection task, animals learn two discriminations. In the presence of Red and Green keys, responses to Red are reinforced after 1-s samples and responses to Green are reinforced after 4-s samples; in the presence of Blue and Yellow keys, responses to Blue are reinforced after 4-s samples and responses to Yellow are reinforced…

Relative versus Absolute Stimulus Control in the Temporal Bisection Task

ERIC Educational Resources Information Center

de Carvalho, Marilia Pinhiero; Machado, Armando

2012-01-01

When subjects learn to associate two sample durations with two comparison keys, do they learn to associate the keys with the short and long samples (relational hypothesis), or with the specific sample durations (absolute hypothesis)? We exposed 16 pigeons to an ABA design in which phases A and B corresponded to tasks using samples of 1 s and 4 s,…

Generating Enhanced Natural Environments and Terrain for Interactive Combat Simulations (GENETICS)

DTIC Science & Technology

2005-09-01

split to avoid T-junctions ........................................................................52 Figure 2-23 Longest edge bisection...database. This feature allows trainers the flexibility to use the same terrain repeatedly or use a new one each time, forcing trainees to avoid ...model are favored to create a good surface approximation. Cracks are avoided by projecting primitives and their respective textures onto multiple

A New Computational Technique for the Generation of Optimised Aircraft Trajectories

NASA Astrophysics Data System (ADS)

Chircop, Kenneth; Gardi, Alessandro; Zammit-Mangion, David; Sabatini, Roberto

2017-12-01

A new computational technique based on Pseudospectral Discretisation (PSD) and adaptive bisection ɛ-constraint methods is proposed to solve multi-objective aircraft trajectory optimisation problems formulated as nonlinear optimal control problems. This technique is applicable to a variety of next-generation avionics and Air Traffic Management (ATM) Decision Support Systems (DSS) for strategic and tactical replanning operations. These include the future Flight Management Systems (FMS) and the 4-Dimensional Trajectory (4DT) planning and intent negotiation/validation tools envisaged by SESAR and NextGen for a global implementation. In particular, after describing the PSD method, the adaptive bisection ɛ-constraint method is presented to allow an efficient solution of problems in which two or multiple performance indices are to be minimized simultaneously. Initial simulation case studies were performed adopting suitable aircraft dynamics models and addressing a classical vertical trajectory optimisation problem with two objectives simultaneously. Subsequently, a more advanced 4DT simulation case study is presented with a focus on representative ATM optimisation objectives in the Terminal Manoeuvring Area (TMA). The simulation results are analysed in-depth and corroborated by flight performance analysis, supporting the validity of the proposed computational techniques.

A genetically encoded and gate for cell-targeted metabolic labeling of proteins.

PubMed

Mahdavi, Alborz; Segall-Shapiro, Thomas H; Kou, Songzi; Jindal, Granton A; Hoff, Kevin G; Liu, Shirley; Chitsaz, Mohsen; Ismagilov, Rustem F; Silberg, Jonathan J; Tirrell, David A

2013-02-27

We describe a genetic AND gate for cell-targeted metabolic labeling and proteomic analysis in complex cellular systems. The centerpiece of the AND gate is a bisected methionyl-tRNA synthetase (MetRS) that charges the Met surrogate azidonorleucine (Anl) to tRNA(Met). Cellular protein labeling occurs only upon activation of two different promoters that drive expression of the N- and C-terminal fragments of the bisected MetRS. Anl-labeled proteins can be tagged with fluorescent dyes or affinity reagents via either copper-catalyzed or strain-promoted azide-alkyne cycloaddition. Protein labeling is apparent within 5 min after addition of Anl to bacterial cells in which the AND gate has been activated. This method allows spatial and temporal control of proteomic labeling and identification of proteins made in specific cellular subpopulations. The approach is demonstrated by selective labeling of proteins in bacterial cells immobilized in the center of a laminar-flow microfluidic channel, where they are exposed to overlapping, opposed gradients of inducers of the N- and C-terminal MetRS fragments. The observed labeling profile is predicted accurately from the strengths of the individual input signals.

A Genetically Encoded AND Gate for Cell-Targeted Metabolic Labeling of Proteins

PubMed Central

Mahdavi, Alborz; Segall-Shapiro, Thomas H.; Kou, Songzi; Jindal, Granton A.; Hoff, Kevin G.; Liu, Shirley; Chitsaz, Mohsen; Ismagilov, Rustem F.; Silberg, Jonathan J.; Tirrell, David A.

2013-01-01

We describe a genetic AND gate for cell-targeted metabolic labeling and proteomic analysis in complex cellular systems. The centerpiece of the AND gate is a bisected methionyl-tRNA synthetase (MetRS) that charges the Met surrogate azidonorleucine (Anl) to tRNAMet. Cellular protein labeling occurs only upon activation of two different promoters that drive expression of the N- and C-terminal fragments of the bisected MetRS. Anl-labeled proteins can be tagged with fluorescent dyes or affinity reagents via either copper-catalyzed or strain-promoted azide-alkyne cycloaddition. Protein labeling is apparent within five minutes after addition of Anl to bacterial cells in which the AND gate has been activated. This method allows spatial and temporal control of proteomic labeling and identification of proteins made in specific cellular subpopulations. The approach is demonstrated by selective labeling of proteins in bacterial cells immobilized in the center of a laminar-flow microfluidic channel, where they are exposed to overlapping, opposed gradients of inducers of the N- and C-terminal MetRS fragments. The observed labeling profile is predicted accurately from the strengths of the individual input signals. PMID:23406315

Cognitive abilities required in time judgment depending on the temporal tasks used: A comparison of children and adults.

PubMed

Droit-Volet, S; Wearden, J H; Zélanti, P S

2015-01-01

The aim of this study was to examine age-related differences in time judgments during childhood as a function of the temporal task used. Children aged 5 and 8 years, as well as adults, were submitted to 3 temporal tasks (bisection, generalization and reproduction) with short (0.4/0.8 s) and long durations (8/16 s). Furthermore, their cognitive capacities in terms of working memory, attentional control, and processing speed were assessed by a wide battery of neuropsychological tests. The results showed that the age-related differences in time judgment were greater in the reproduction task than in the temporal discrimination tasks. This task was indeed more demanding in terms of working memory and information processing speed. In addition, the bisection task appeared to be easier for children than the generalization task, whereas these 2 tasks were similar for the adults, although the generalization task required more attention to be paid to the processing of durations. Our study thus demonstrates that it is important to understand the different cognitive processes involved in time judgment as a function of the temporal tasks used before venturing to draw conclusions about the development of time perception capabilities.

Putative porcine embryonic stem cell lines derived from aggregated four-celled cloned embryos produced by oocyte bisection cloning.

PubMed

Siriboon, Chawalit; Lin, Yu-Hsuan; Kere, Michel; Chen, Chun-Da; Chen, Lih-Ren; Chen, Chien-Hong; Tu, Ching-Fu; Lo, Neng-Wen; Ju, Jyh-Cherng

2015-01-01

We attempted to isolate ES cell lines using inner cell masses from high-quality cloned porcine blastocysts. After being seeded onto feeders, embryos had better (P < 0.05) attachment, outgrowth formation and primary colonization in both 2× and 3× aggregated cloned embryos (62.8, 42.6 and 12.8% vs. 76.2, 55.2 and 26.2%, respectively) compared to the non-aggregated group (41.6, 23.4 and 3.9%). Effects of feeder types (STO vs. MEF) and serum sources (FBS vs. KSR) on extraction of cloned embryo-derived porcine ES cells were examined. More (17.1%) ntES cell lines over Passage 3 were generated in the MEF/KSR group. However, ntES cells cultured in KSR-supplemented medium had a low proliferation rate with defective morphology, and eventually underwent differentiation or apoptosis subsequently. Approximately 26.1, 22.7 and 35.7% of primary colonies were formed after plating embryos in DMEM, DMEM/F12 and α-MEM media, respectively. Survival rates of ntES cells cultured in α-MEM, DMEM and DMEM/F12 were 16.7, 4.3 and 6.8%, respectively (P > 0.05). We further examined the beneficial effect of TSA treatment of 3× aggregated cloned embryos on establishment of ntES cell lines. Primary colony numbers and survival rates of ntES cells beyond passage 3 were higher (P < 0.05) in those derived from TSA-treated 3× blastocysts (36.7 and 26.7%) than from the non-treated aggregated group (23.1 and 11.5%). These cells, remaining undifferentiated over 25 passages, had alkaline phosphatase activity and expressed ES specific markers Oct4, Nanog, Sox2, and Rex01. Moreover, these ntES cells successfully differentiated into embryoid bodies (EBs) that expressed specific genes of all three germ layers after being cultured in LIF-free medium. In conclusion, we have successfully derived putative porcine ntES cells with high efficiency from quality cloned embryos produced by embryo aggregation, and optimized the ES cell culture system suitable for establishing and maintaining ntES cell lines in undifferentiated state.

Putative Porcine Embryonic Stem Cell Lines Derived from Aggregated Four-Celled Cloned Embryos Produced by Oocyte Bisection Cloning

PubMed Central

Siriboon, Chawalit; Lin, Yu-Hsuan; Kere, Michel; Chen, Chun-Da; Chen, Lih-Ren; Chen, Chien-Hong; Tu, Ching-Fu; Lo, Neng-Wen; Ju, Jyh-Cherng

2015-01-01

We attempted to isolate ES cell lines using inner cell masses from high-quality cloned porcine blastocysts. After being seeded onto feeders, embryos had better (P < 0.05) attachment, outgrowth formation and primary colonization in both 2× and 3× aggregated cloned embryos (62.8, 42.6 and12.8% vs. 76.2, 55.2 and 26.2%, respectively) compared to the non-aggregated group (41.6, 23.4 and 3.9%). Effects of feeder types (STO vs. MEF) and serum sources (FBS vs. KSR) on extraction of cloned embryo-derived porcine ES cells were examined. More (17.1%) ntES cell lines over Passage 3 were generated in the MEF/KSR group. However, ntES cells cultured in KSR-supplemented medium had a low proliferation rate with defective morphology, and eventually underwent differentiation or apoptosis subsequently. Approximately 26.1, 22.7 and 35.7% of primary colonies were formed after plating embryos in DMEM, DMEM/F12 and α-MEM media, respectively. Survival rates of ntES cells cultured in α-MEM, DMEM and DMEM/F12 were 16.7, 4.3 and 6.8%, respectively (P > 0.05). We further examined the beneficial effect of TSA treatment of 3× aggregated cloned embryos on establishment of ntES cell lines. Primary colony numbers and survival rates of ntES cells beyond passage 3 were higher (P < 0.05) in those derived from TSA-treated 3× blastocysts (36.7 and 26.7%) than from the non-treated aggregated group (23.1 and 11.5%). These cells, remaining undifferentiated over 25 passages, had alkaline phosphatase activity and expressed ES specific markers Oct4, Nanog, Sox2, and Rex01. Moreover, these ntES cells successfully differentiated into embryoid bodies (EBs) that expressed specific genes of all three germ layers after being cultured in LIF-free medium. In conclusion, we have successfully derived putative porcine ntES cells with high efficiency from quality cloned embryos produced by embryo aggregation, and optimized the ES cell culture system suitable for establishing and maintaining ntES cell lines in undifferentiated state. PMID:25680105

From Open Geographical Data to Tangible Maps: Improving the Accessibility of Maps for Visually Impaired People

NASA Astrophysics Data System (ADS)

Ducasse, J.; Macé, M.; Jouffrais, C.

2015-08-01

Visual maps must be transcribed into (interactive) raised-line maps to be accessible for visually impaired people. However, these tactile maps suffer from several shortcomings: they are long and expensive to produce, they cannot display a large amount of information, and they are not dynamically modifiable. A number of methods have been developed to automate the production of raised-line maps, but there is not yet any tactile map editor on the market. Tangible interactions proved to be an efficient way to help a visually impaired user manipulate spatial representations. Contrary to raised-line maps, tangible maps can be autonomously constructed and edited. In this paper, we present the scenarios and the main expected contributions of the AccessiMap project, which is based on the availability of many sources of open spatial data: 1/ facilitating the production of interactive tactile maps with the development of an open-source web-based editor; 2/ investigating the use of tangible interfaces for the autonomous construction and exploration of a map by a visually impaired user.

Vertical perceptual span and the processing of visual signals in reading.

PubMed

Cauchard, Fabrice; Eyrolle, Hélène; Cellier, Jean-Marie; Hyönä, Jukka

2010-02-01

A previous study by Pollatsek et al. ( 1993 ) claims that the perceptual span in reading is restricted to the fixated line, i.e. readers typically focus their visual attention on the line of text being read. The present study investigated whether readers make use of content structure signals (paragraph indentations and topic headings) present several lines away from the currently fixated line. We reasoned that as these signals are low-resolution visual objects (as opposed to letter and word identity), readers may attend to them even if they are located some distance away from the fixated line. Participants read a hierarchically organized multi-topic expository text containing structure signals in either a normal condition or a window condition, where the text disappeared above and below a vertical 3° gaze-contingent region. After reading, participants were asked to produce a written recall of the text. The results showed that the overall reading rate was not affected by the window. Nevertheless, the headings were reread more in the normal condition than in the window one. In addition, more topics were recalled in the normal than in the window condition. We interpret the results as indicating that the readers visually attend to useful text layout features while considering bigger units than single text lines. The perception of topic headings located away from the fixated line may favour long-range regressions towards them, which in turn may favour text comprehension. This claim is consistent with previous studies that showed that look-back fixations to headings are performed with an integrative intent.

Analysis of chaotic saddles in a nonlinear vibro-impact system

NASA Astrophysics Data System (ADS)

Feng, Jinqian

2017-07-01

In this paper, a computational investigation of chaotic saddles in a nonlinear vibro-impact system is presented. For a classical Duffing vibro-impact oscillator, we employ the bisection procedure and an improved stagger-and-step method to present evidence of visual chaotic saddles on the fractal basin boundary and in the internal basin, respectively. The results show that the period saddles play an important role in the evolution of chaotic saddle. The dynamics mechanics of three types of bifurcation such as saddle-node bifurcation, chaotic saddle crisis bifurcation and interior chaotic crisis bifurcation are discussed. The results reveal that the period saddle created at saddle-node bifurcation is responsible for the switch of the internal chaotic saddle to the boundary chaotic saddle. At chaotic saddle crisis bifurcation, a large chaotic saddle can divide into two different chaotic saddle connected by a period saddle. The intersection points between stable and unstable manifolds of this period saddle supply access for chaotic orbits from one chaotic saddle to another and eventually induce the coupling of these two chaotic saddle. Interior chaotic crisis bifurcation is associated with the intersection of stable and unstable manifolds of the period saddle connecting two chaotic invariant sets. In addition, the gaps in chaotic saddle is responsible for the fractal structure.

Visual Testing: An Experimental Assessment of the Encoding Specificity Hypothesis.

ERIC Educational Resources Information Center

DeMelo, Hermes T.; And Others

This study of 96 high school biology students investigates the effectiveness of visual instruction composed of simple line drawings and printed words as compared to printed-words-only instruction, visual tests, and the interaction between visual or non-visual mode of instruction and mode of testing. The subjects were randomly assigned to be given…

Smile line assessment comparing quantitative measurement and visual estimation.

PubMed

Van der Geld, Pieter; Oosterveld, Paul; Schols, Jan; Kuijpers-Jagtman, Anne Marie

2011-02-01

Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation according to a standard categorization are more practical for regular diagnostics. Our objective in this study was to compare 2 semiquantitative methods with quantitative measurements for reliability and agreement. The faces of 122 male participants were individually registered by using digital videography. Spontaneous and posed smiles were captured. On the records, maxillary lip line heights and tooth display were digitally measured on each tooth and also visually estimated according to 3-grade and 4-grade scales. Two raters were involved. An error analysis was performed. Reliability was established with kappa statistics. Interexaminer and intraexaminer reliability values were high, with median kappa values from 0.79 to 0.88. Agreement of the 3-grade scale estimation with quantitative measurement showed higher median kappa values (0.76) than the 4-grade scale estimation (0.66). Differentiating high and gummy smile lines (4-grade scale) resulted in greater inaccuracies. The estimation of a high, average, or low smile line for each tooth showed high reliability close to quantitative measurements. Smile line analysis can be performed reliably with a 3-grade scale (visual) semiquantitative estimation. For a more comprehensive diagnosis, additional measuring is proposed, especially in patients with disproportional gingival display. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

Clustergrammer, a web-based heatmap visualization and analysis tool for high-dimensional biological data

PubMed Central

Fernandez, Nicolas F.; Gundersen, Gregory W.; Rahman, Adeeb; Grimes, Mark L.; Rikova, Klarisa; Hornbeck, Peter; Ma’ayan, Avi

2017-01-01

Most tools developed to visualize hierarchically clustered heatmaps generate static images. Clustergrammer is a web-based visualization tool with interactive features such as: zooming, panning, filtering, reordering, sharing, performing enrichment analysis, and providing dynamic gene annotations. Clustergrammer can be used to generate shareable interactive visualizations by uploading a data table to a web-site, or by embedding Clustergrammer in Jupyter Notebooks. The Clustergrammer core libraries can also be used as a toolkit by developers to generate visualizations within their own applications. Clustergrammer is demonstrated using gene expression data from the cancer cell line encyclopedia (CCLE), original post-translational modification data collected from lung cancer cells lines by a mass spectrometry approach, and original cytometry by time of flight (CyTOF) single-cell proteomics data from blood. Clustergrammer enables producing interactive web based visualizations for the analysis of diverse biological data. PMID:28994825

PCSYS: The optimal design integration system picture drawing system with hidden line algorithm capability for aerospace vehicle configurations

NASA Technical Reports Server (NTRS)

Hague, D. S.; Vanderburg, J. D.

1977-01-01

A vehicle geometric definition based upon quadrilateral surface elements to produce realistic pictures of an aerospace vehicle. The PCSYS programs can be used to visually check geometric data input, monitor geometric perturbations, and to visualize the complex spatial inter-relationships between the internal and external vehicle components. PCSYS has two major component programs. The between program, IMAGE, draws a complex aerospace vehicle pictorial representation based on either an approximate but rapid hidden line algorithm or without any hidden line algorithm. The second program, HIDDEN, draws a vehicle representation using an accurate but time consuming hidden line algorithm.

Power line detection system

DOEpatents

Latorre, V.R.; Watwood, D.B.

1994-09-27

A short-range, radio frequency (RF) transmitting-receiving system that provides both visual and audio warnings to the pilot of a helicopter or light aircraft of an up-coming power transmission line complex. Small, milliwatt-level narrowband transmitters, powered by the transmission line itself, are installed on top of selected transmission line support towers or within existing warning balls, and provide a continuous RF signal to approaching aircraft. The on-board receiver can be either a separate unit or a portion of the existing avionics, and can also share an existing antenna with another airborne system. Upon receipt of a warning signal, the receiver will trigger a visual and an audio alarm to alert the pilot to the potential power line hazard. 4 figs.

Development of the navigation system for visually impaired.

PubMed

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.

Neural Activity Associated with Visual Search for Line Drawings on AAC Displays: An Exploration of the Use of fMRI.

PubMed

Wilkinson, Krista M; Dennis, Nancy A; Webb, Christina E; Therrien, Mari; Stradtman, Megan; Farmer, Jacquelyn; Leach, Raevynn; Warrenfeltz, Megan; Zeuner, Courtney

2015-01-01

Visual aided augmentative and alternative communication (AAC) consists of books or technologies that contain visual symbols to supplement spoken language. A common observation concerning some forms of aided AAC is that message preparation can be frustratingly slow. We explored the uses of fMRI to examine the neural correlates of visual search for line drawings on AAC displays in 18 college students under two experimental conditions. Under one condition, the location of the icons remained stable and participants were able to learn the spatial layout of the display. Under the other condition, constant shuffling of the locations of the icons prevented participants from learning the layout, impeding rapid search. Brain activation was contrasted under these conditions. Rapid search in the stable display was associated with greater activation of cortical and subcortical regions associated with memory, motor learning, and dorsal visual pathways compared to the search in the unpredictable display. Rapid search for line drawings on stable AAC displays involves not just the conceptual knowledge of the symbol meaning but also the integration of motor, memory, and visual-spatial knowledge about the display layout. Further research must study individuals who use AAC, as well as the functional effect of interventions that promote knowledge about array layout.

How accurate are interpretations of curriculum-based measurement progress monitoring data? Visual analysis versus decision rules.

PubMed

Van Norman, Ethan R; Christ, Theodore J

2016-10-01

Curriculum based measurement of oral reading (CBM-R) is used to monitor the effects of academic interventions for individual students. Decisions to continue, modify, or terminate these interventions are made by interpreting time series CBM-R data. Such interpretation is founded upon visual analysis or the application of decision rules. The purpose of this study was to compare the accuracy of visual analysis and decision rules. Visual analysts interpreted 108 CBM-R progress monitoring graphs one of three ways: (a) without graphic aids, (b) with a goal line, or (c) with a goal line and a trend line. Graphs differed along three dimensions, including trend magnitude, variability of observations, and duration of data collection. Automated trend line and data point decision rules were also applied to each graph. Inferential analyses permitted the estimation of the probability of a correct decision (i.e., the student is improving - continue the intervention, or the student is not improving - discontinue the intervention) for each evaluation method as a function of trend magnitude, variability of observations, and duration of data collection. All evaluation methods performed better when students made adequate progress. Visual analysis and decision rules performed similarly when observations were less variable. Results suggest that educators should collect data for more than six weeks, take steps to control measurement error, and visually analyze graphs when data are variable. Implications for practice and research are discussed. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Materiel Testing in the Tropics (6th Ed)

DTIC Science & Technology

1979-04-01

ceramics Test methodology Panama Canal Zone Textiles Plastics Tropic Test Center Protective coatings Tropical animals 20. (cont) of Materiel Testing in...Canal Zone . .. 1-3 D Materiel Testing in the Panama Canal Zone . . . . . . . ... . 1-5 E Canal Zone Environment--Brief Overview .. .. .... ...... 1-6...trapped there, and by the heavy biomass of the canopy itself. E. CANAL ZONE ENVIRONMENT--BRIEF OVERVIEW The Canal Zone (see frontispiece) bisects the

Cognitive Abilities Explaining Age-Related Changes in Time Perception of Short and Long Durations

ERIC Educational Resources Information Center

Zelanti, Pierre S.; Droit-Volet, Sylvie

2011-01-01

The current study investigated how the development of cognitive abilities explains the age-related changes in temporal judgment over short and long duration ranges from 0.5 to 30 s. Children (5- and 9-year-olds) as well as adults were given a temporal bisection task with four different duration ranges: a duration range shorter than 1 s, two…

A Common Representational System Governed by Weber's Law: Nonverbal Numerical Similarity Judgments in 6-Year-Olds and Rhesus Macaques

ERIC Educational Resources Information Center

Jordan, Kerry E.; Brannon, Elizabeth M.

2006-01-01

This study compared nonverbal numerical processing in 6-year-olds with that in nonhuman animals using a numerical bisection task. In the study, 16 children were trained on a delayed match-to-sample paradigm to match exemplars of two anchor numerosities. Children were then required to indicate whether a sample intermediate to the anchor values was…

Teaching Molecular Symmetry of Dihedral Point Groups by Drawing Useful 2D Projections

ERIC Educational Resources Information Center

Chen, Lan; Sun, Hongwei; Lai, Chengming

2015-01-01

There are two main difficulties in studying molecular symmetry of dihedral point groups. One is locating the C[subscript 2] axes perpendicular to the C[subscript n] axis, while the other is finding the s[subscript]d planes which pass through the C[subscript n] axis and bisect the angles formed by adjacent C[subscript 2] axes. In this paper, a…

Contractile properties of rat skeletal muscles following storage at 4 degrees C.

PubMed

van der Heijden, E P; Kroese, A B; Stremel, R W; Bär, P R; Kon, M; Werker, P M

1999-07-01

The purpose of this study was to assess the potential of preservation solutions for protecting skeletal muscle function during storage at 4 degrees C. The soleus and the cutaneus trunci (CT) from the rat were stored for 2, 8 or 16 h at 4 degrees C in University of Wisconsin solution (UW), HTK-Bretschneider solution (HTK) or Krebs-Henseleit solution (KH). After storage, muscles were stimulated electrically to analyse the isometric contractile properties, such as the maximum tetanic tension (P(0)). Histological analysis was also performed. In separate experiments, the effect of the diffusion distance on muscle preservation was studied by bisecting the soleus. After 8 h of storage in UW or HTK, the contractile properties of the CT were similar to those of the control, whereas those of the soleus were reduced (P(0) values of 16% and 69% of control in UW and HTK respectively). At 16 h, the contractile properties of the CT (P(O) 28%) were again better preserved than those of the soleus (P(0) 9%). Muscle function deteriorated most after storage in KH (P(0) at 16 h: soleus, 3%; CT, 17%). The bisected soleus was equally well preserved as the CT (P(O) of bisected soleus at 8 h in UW and HTK: 86%). The functional data corresponded well with the histological data, which showed increasing muscle fibre derangement with increasing storage time. For both muscles and all solutions, the threshold stimulus current increased with increasing storage time (control, 0.1 mA; 16 h, 1.2 mA) and was strongly correlated with the deterioration in contractile properties. It is concluded that, at 4 degrees C, muscle is preserved better in UW and HTK (intracellular-like solutions) than in KH (extracellular-like solution). The soleus and CT were best protected in HTK. The diffusion distance is a critical factor for successful preservation of muscle function at 4 degrees C. The reduced function after 16 h of storage at 4 degrees C was caused by hypercontraction and necrosis of about 25% of the muscle fibres, and by deterioration of the electrical component of excitation-contraction coupling of the remaining fibres.

Plasmodium species differentiation by non-expert on-line volunteers for remote malaria field diagnosis.

PubMed

Ortiz-Ruiz, Alejandra; Postigo, María; Gil-Casanova, Sara; Cuadrado, Daniel; Bautista, José M; Rubio, José Miguel; Luengo-Oroz, Miguel; Linares, María

2018-01-30

Routine field diagnosis of malaria is a considerable challenge in rural and low resources endemic areas mainly due to lack of personnel, training and sample processing capacity. In addition, differential diagnosis of Plasmodium species has a high level of misdiagnosis. Real time remote microscopical diagnosis through on-line crowdsourcing platforms could be converted into an agile network to support diagnosis-based treatment and malaria control in low resources areas. This study explores whether accurate Plasmodium species identification-a critical step during the diagnosis protocol in order to choose the appropriate medication-is possible through the information provided by non-trained on-line volunteers. 88 volunteers have performed a series of questionnaires over 110 images to differentiate species (Plasmodium falciparum, Plasmodium ovale, Plasmodium vivax, Plasmodium malariae, Plasmodium knowlesi) and parasite staging from thin blood smear images digitalized with a smartphone camera adapted to the ocular of a conventional light microscope. Visual cues evaluated in the surveys include texture and colour, parasite shape and red blood size. On-line volunteers are able to discriminate Plasmodium species (P. falciparum, P. malariae, P. vivax, P. ovale, P. knowlesi) and stages in thin-blood smears according to visual cues observed on digitalized images of parasitized red blood cells. Friendly textual descriptions of the visual cues and specialized malaria terminology is key for volunteers learning and efficiency. On-line volunteers with short-training are able to differentiate malaria parasite species and parasite stages from digitalized thin smears based on simple visual cues (shape, size, texture and colour). While the accuracy of a single on-line expert is far from perfect, a single parasite classification obtained by combining the opinions of multiple on-line volunteers over the same smear, could improve accuracy and reliability of Plasmodium species identification in remote malaria diagnosis.

Assessing Visuospatial Skills in Parkinson's: Comparison of Neuropsychological Assessment Battery Visual Discrimination to the Judgment of Line Orientation.

PubMed

Renfroe, Jenna B; Turner, Travis H; Hinson, Vanessa K

2017-02-01

Judgment of Line Orientation (JOLO) test is widely used in assessing visuospatial deficits in Parkinson's disease (PD). The neuropsychological assessment battery (NAB) offers the Visual Discrimination test, with age and education correction, parallel forms, and co-normed standardization sample for comparisons within and between domains. However, NAB Visual Discrimination has not been validated in PD, and may not measure the same construct as JOLO. A heterogeneous sample of 47 PD patients completed the JOLO and NAB Visual Discrimination within a broader neuropsychological evaluation. Pearson correlations assessed relationships between JOLO and NAB Visual Discrimination performances. Raw and demographically corrected scores from JOLO and Visual Discrimination were only weakly correlated. NAB Visual Discrimination subtest was moderately correlated with overall cognitive functioning, whereas the JOLO was not. Despite apparent virtues, results do not support NAB Visual Discrimination as an alternative to JOLO in assessing visuospatial functioning in PD. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Research on conflict detection algorithm in 3D visualization environment of urban rail transit line

NASA Astrophysics Data System (ADS)

Wang, Li; Xiong, Jing; You, Kuokuo

2017-03-01

In this paper, a method of collision detection is introduced, and the theory of three-dimensional modeling of underground buildings and urban rail lines is realized by rapidly extracting the buildings that are in conflict with the track area in the 3D visualization environment. According to the characteristics of the buildings, CSG and B-rep are used to model the buildings based on CSG and B-rep. On the basis of studying the modeling characteristics, this paper proposes to use the AABB level bounding volume method to detect the first conflict and improve the detection efficiency, and then use the triangular rapid intersection detection algorithm to detect the conflict, and finally determine whether the building collides with the track area. Through the algorithm of this paper, we can quickly extract buildings colliding with the influence area of the track line, so as to help the line design, choose the best route and calculate the cost of land acquisition in the three-dimensional visualization environment.

Visual selection and maintenance of the cell lines with high plant regeneration ability and low ploidy level in Dianthus acicularis by monitoring with flow cytometry analysis.

PubMed

Shiba, Tomonori; Mii, Masahiro

2005-12-01

Efficient plant regeneration system from cell suspension cultures was established in D. acicularis (2n=90) by monitoring ploidy level and visual selection of the cultures. The ploidy level of the cell cultures closely related to the shoot regeneration ability. The cell lines comprising original ploidy levels (2C+4C cells corresponding to DNA contents of G1 and G2 cells of diploid plant, respectively) showed high regeneration ability, whereas those containing the cells with 8C or higher DNA C-values showed low or no regeneration ability. The highly regenerable cell lines thus selected consisted of compact cell clumps with yellowish color and relatively moderate growth, suggesting that it is possible to select visually the highly regenerable cell lines with the original ploidy level. All the regenerated plantlets from the highly regenerable cell cultures exhibited normal phenotypes and no variations in ploidy level were observed by flow cytometry (FCM) analysis.

Expanding biological data standards development processes for US IOOS: visual line transect observing community for mammal, bird, and turtle data

USGS Publications Warehouse

Fornwall, M.; Gisiner, R.; Simmons, S. E.; Moustahfid, Hassan; Canonico, G.; Halpin, P.; Goldstein, P.; Fitch, R.; Weise, M.; Cyr, N.; Palka, D.; Price, J.; Collins, D.

2012-01-01

The US Integrated Ocean Observing System (IOOS) has recently adopted standards for biological core variables in collaboration with the US Geological Survey/Ocean Biogeographic Information System (USGS/OBIS-USA) and other federal and non-federal partners. In this Community White Paper (CWP) we provide a process to bring into IOOS a rich new source of biological observing data, visual line transect surveys, and to establish quality data standards for visual line transect observations, an important source of at-sea bird, turtle and marine mammal observation data. The processes developed through this exercise will be useful for other similar biogeographic observing efforts, such as passive acoustic point and line transect observations, tagged animal data, and mark-recapture (photo-identification) methods. Furthermore, we suggest that the processes developed through this exercise will serve as a catalyst for broadening involvement by the larger marine biological data community within the goals and processes of IOOS.

PL-VIO: Tightly-Coupled Monocular Visual–Inertial Odometry Using Point and Line Features

PubMed Central

Zhao, Ji; Guo, Yue; He, Wenhao; Yuan, Kui

2018-01-01

To address the problem of estimating camera trajectory and to build a structural three-dimensional (3D) map based on inertial measurements and visual observations, this paper proposes point–line visual–inertial odometry (PL-VIO), a tightly-coupled monocular visual–inertial odometry system exploiting both point and line features. Compared with point features, lines provide significantly more geometrical structure information on the environment. To obtain both computation simplicity and representational compactness of a 3D spatial line, Plücker coordinates and orthonormal representation for the line are employed. To tightly and efficiently fuse the information from inertial measurement units (IMUs) and visual sensors, we optimize the states by minimizing a cost function which combines the pre-integrated IMU error term together with the point and line re-projection error terms in a sliding window optimization framework. The experiments evaluated on public datasets demonstrate that the PL-VIO method that combines point and line features outperforms several state-of-the-art VIO systems which use point features only. PMID:29642648

Separation of fatty acid methyl esters by GC-online hydrogenation × GC.

PubMed

Delmonte, Pierluigi; Fardin-Kia, Ali Reza; Rader, Jeanne I

2013-02-05

The separation of fatty acid methyl esters (FAME) provided by a 200 m × 0.25 mm SLB-IL111 capillary column is enhanced by adding a second dimension of separation ((2)D) in a GC × GC design. Rather than employing two GC columns of different polarities or using different elution temperatures, the separation in the two-dimensional space is achieved by altering the chemical structure of selected analytes between the two dimensions of separation. A capillary tube coated with palladium is added between the first dimension of separation ((1)D) column and the cryogenic modulator, providing the reduction of unsaturated FAMEs to their fully saturated forms. The (2)D separation is achieved using a 2.5 m × 0.10 mm SLB-IL111 capillary column and separates FAMEs based solely on their carbon skeleton. The two-dimensional separation can be easily interpreted based on the principle that all the saturated FAMEs lie on a straight diagonal line bisecting the separation plane, while the FAMEs with the same carbon skeleton but differing in the number, geometric configuration or position of double bonds lie on lines parallel to the (1)D time axis. This technique allows the separation of trans fatty acids (FAs) and polyunsaturated FAs (PUFAs) in a single experiment and eliminates the overlap between PUFAs with different chain lengths. To our knowledge, this the first example of GC × GC in which a chemical change is instituted between the two dimensions to alter the relative retentions of components and identify unsaturated FAMEs.

Can free-viewing perceptual asymmetries be explained by scanning, pre-motor or attentional biases?

PubMed

Nicholls, Michael E R; Roberts, Georgina R

2002-04-01

Judgments of relative magnitude between the left and right sides of a stimulus are generally weighted toward the features contained on the left side. This leftward perceptual bias could be the result of, (a) left-to-right scanning biases, (b) pre-motor activation of the right hemisphere, or (c) a left hemispatial attentional bias. The relative merits of these explanations of perceptual asymmetry were investigated. In Experiment 1, English and Hebrew readers made luminance judgements for two left/right mirror-reversed luminance gradients (greyscales task). Despite different reading/scanning habits, both groups exhibited a leftward perceptual bias. English and Hebrew readers also performed a line bisection task. Scanning biases were controlled by asking participants to follow a marker as it moved left-to-right or right-to-left and then stop it as it reached the midpoint of the line. Despite controlling scanning, a leftward bias was observed in both groups. In Experiment 2, peripheral spatial cues were presented prior to the greyscales stimuli. English readers showed a reduction in the leftward bias for right-sided cues as compared to left-sided and neutral cues. Right-side cues presumably overcame a pre-existing leftward attentional bias. In both experiments, pre-motor activation was controlled using bimanual responses. Despite this control, a leftward bias was observed throughout the study. The data support the attentional bias account of leftward perceptual biases over the scanning and pre-motor activation accounts. Whether or not unilateral hemispheric activation provides an adequate account of this attentional bias is discussed.

BATSE Gamma-Ray Burst Line Search. IV. Line Candidates from the Visual Search

NASA Astrophysics Data System (ADS)

Band, D. L.; Ryder, S.; Ford, L. A.; Matteson, J. L.; Palmer, D. M.; Teegarden, B. J.; Briggs, M. S.; Paciesas, W. S.; Pendleton, G. N.; Preece, R. D.

1996-02-01

We evaluate the significance of the line candidates identified by a visual search of burst spectra from BATSE's Spectroscopy Detectors. None of the candidates satisfy our detection criteria: an F-test probability less than 10-4 for a feature in one detector and consistency among the detectors that viewed the burst. Most of the candidates are not very significant and are likely to be fluctuations. Because of the expectation of finding absorption lines, the search was biased toward absorption features. We do not have a quantitative measure of the completeness of the search, which would enable a comparison with previous missions. Therefore, a more objective computerized search has begun.

Application of visual basic in high-throughput mass spectrometry-directed purification of combinatorial libraries.

PubMed

Li, B; Chan, E C Y

2003-01-01

We present an approach to customize the sample submission process for high-throughput purification (HTP) of combinatorial parallel libraries using preparative liquid chromatography electrospray ionization mass spectrometry. In this study, Visual Basic and Visual Basic for Applications programs were developed using Microsoft Visual Basic 6 and Microsoft Excel 2000, respectively. These programs are subsequently applied for the seamless electronic submission and handling of data for HTP. Functions were incorporated into these programs where medicinal chemists can perform on-line verification of the purification status and on-line retrieval of postpurification data. The application of these user friendly and cost effective programs in our HTP technology has greatly increased our work efficiency by reducing paper work and manual manipulation of data.

Surveying the Maize community for their diversity and pedigree visualization needs to prioritize tool development and curation

PubMed Central

Braun, Bremen L.; Schott, David A.; Portwood, II, John L.; Schaeffer, Mary L.; Harper, Lisa C.; Gardiner, Jack M.; Cannon, Ethalinda K.; Andorf, Carson M.

2017-01-01

Abstract The Maize Genetics and Genomics Database (MaizeGDB) team prepared a survey to identify breeders’ needs for visualizing pedigrees, diversity data and haplotypes in order to prioritize tool development and curation efforts at MaizeGDB. The survey was distributed to the maize research community on behalf of the Maize Genetics Executive Committee in Summer 2015. The survey garnered 48 responses from maize researchers, of which more than half were self-identified as breeders. The survey showed that the maize researchers considered their top priorities for visualization as: (i) displaying single nucleotide polymorphisms in a given region for a given list of lines, (ii) showing haplotypes for a given list of lines and (iii) presenting pedigree relationships visually. The survey also asked which populations would be most useful to display. The following two populations were on top of the list: (i) 3000 publicly available maize inbred lines used in Romay et al. (Comprehensive genotyping of the USA national maize inbred seed bank. Genome Biol, 2013;14:R55) and (ii) maize lines with expired Plant Variety Protection Act (ex-PVP) certificates. Driven by this strong stakeholder input, MaizeGDB staff are currently working in four areas to improve its interface and web-based tools: (i) presenting immediate progenies of currently available stocks at the MaizeGDB Stock pages, (ii) displaying the most recent ex-PVP lines described in the Germplasm Resources Information Network (GRIN) on the MaizeGDB Stock pages, (iii) developing network views of pedigree relationships and (iv) visualizing genotypes from SNP-based diversity datasets. These survey results can help other biological databases to direct their efforts according to user preferences as they serve similar types of data sets for their communities. Database URL: https://www.maizegdb.org PMID:28605768

Development of voice navigation system for the visually impaired by using IC tags.

PubMed

Takatori, Norihiko; Nojima, Kengo; Matsumoto, Masashi; Yanashima, Kenji; Magatani, Kazushige

2006-01-01

There are about 300,000 visually impaired persons in Japan. Most of them are old persons and, cannot become skillful in using a white cane, even if they make effort to learn how to use a white cane. Therefore, some guiding system that supports the independent activities of the visually impaired are required. In this paper, we will describe about a developed white cane system that supports the independent walking of the visually impaired in the indoor space. This system is composed of colored navigation lines that include IC tags and an intelligent white cane that has a navigation computer. In our system colored navigation lines that are put on the floor of the target space from the start point to the destination and IC tags that are set at the landmark point are used for indication of the route to the destination. The white cane has a color sensor, an IC tag transceiver and a computer system that includes a voice processor. This white cane senses the navigation line that has target color by a color sensor. When a color sensor finds the target color, the white cane informs a white cane user that he/she is on the navigation line by vibration. So, only following this vibration, the user can reach the destination. However, at some landmark points, guidance is necessary. At these points, an IC tag is set under the navigation line. The cane makes communication with the tag and informs the user about the land mark pint by pre recorded voice. Ten normal subjects who were blindfolded were tested with our developed system. All of them could walk along navigation line. And the IC tag information system worked well. Therefore, we have concluded that our system will be a very valuable one to support activities of the visually impaired.

Multidimensional structured data visualization method and apparatus, text visualization method and apparatus, method and apparatus for visualizing and graphically navigating the world wide web, method and apparatus for visualizing hierarchies

DOEpatents

Risch, John S [Kennewick, WA; Dowson, Scott T [West Richland, WA; Hart, Michelle L [Richland, WA; Hatley, Wes L [Kennewick, WA

2008-05-13

A method of displaying correlations among information objects comprises receiving a query against a database; obtaining a query result set; and generating a visualization representing the components of the result set, the visualization including one of a plane and line to represent a data field, nodes representing data values, and links showing correlations among fields and values. Other visualization methods and apparatus are disclosed.

Multidimensional structured data visualization method and apparatus, text visualization method and apparatus, method and apparatus for visualizing and graphically navigating the world wide web, method and apparatus for visualizing hierarchies

DOEpatents

Risch, John S [Kennewick, WA; Dowson, Scott T [West Richland, WA

2012-03-06

A method of displaying correlations among information objects includes receiving a query against a database; obtaining a query result set; and generating a visualization representing the components of the result set, the visualization including one of a plane and line to represent a data field, nodes representing data values, and links showing correlations among fields and values. Other visualization methods and apparatus are disclosed.

Visual Analysis among Novices: Training and Trend Lines as Graphic Aids

ERIC Educational Resources Information Center

Nelson, Peter M.; Van Norman, Ethan R.; Christ, Theodore J.

2017-01-01

The current study evaluated the degree to which novice visual analysts could discern trends in simulated time-series data across differing levels of variability and extreme values. Forty-five novice visual analysts were trained in general principles of visual analysis. One group received brief training on how to identify and omit extreme values.…

Map LineUps: Effects of spatial structure on graphical inference.

PubMed

Beecham, Roger; Dykes, Jason; Meulemans, Wouter; Slingsby, Aidan; Turkay, Cagatay; Wood, Jo

2017-01-01

Fundamental to the effective use of visualization as an analytic and descriptive tool is the assurance that presenting data visually provides the capability of making inferences from what we see. This paper explores two related approaches to quantifying the confidence we may have in making visual inferences from mapped geospatial data. We adapt Wickham et al.'s 'Visual Line-up' method as a direct analogy with Null Hypothesis Significance Testing (NHST) and propose a new approach for generating more credible spatial null hypotheses. Rather than using as a spatial null hypothesis the unrealistic assumption of complete spatial randomness, we propose spatially autocorrelated simulations as alternative nulls. We conduct a set of crowdsourced experiments (n=361) to determine the just noticeable difference (JND) between pairs of choropleth maps of geographic units controlling for spatial autocorrelation (Moran's I statistic) and geometric configuration (variance in spatial unit area). Results indicate that people's abilities to perceive differences in spatial autocorrelation vary with baseline autocorrelation structure and the geometric configuration of geographic units. These results allow us, for the first time, to construct a visual equivalent of statistical power for geospatial data. Our JND results add to those provided in recent years by Klippel et al. (2011), Harrison et al. (2014) and Kay & Heer (2015) for correlation visualization. Importantly, they provide an empirical basis for an improved construction of visual line-ups for maps and the development of theory to inform geospatial tests of graphical inference.

Effect of drivers' age and push button locations on visual time off road, steering wheel deviation and safety perception.

PubMed

Dukic, T; Hanson, L; Falkmer, T

2006-01-15

The study examined the effects of manual control locations on two groups of randomly selected young and old drivers in relation to visual time off road, steering wheel deviation and safety perception. Measures of visual time off road, steering wheel deviations and safety perception were performed with young and old drivers during real traffic. The results showed an effect of both driver's age and button location on the dependent variables. Older drivers spent longer visual time off road when pushing the buttons and had larger steering wheel deviations. Moreover, the greater the eccentricity between the normal line of sight and the button locations, the longer the visual time off road and the larger the steering wheel deviations. No interaction effect between button location and age was found with regard to visual time off road. Button location had an effect on perceived safety: the further away from the normal line of sight the lower the rating.

Visual Agnosia for Line Drawings and Silhouettes without Apparent Impairment of Real-Object Recognition: A Case Report

PubMed Central

Hiraoka, Kotaro; Suzuki, Kyoko; Hirayama, Kazumi; Mori, Etsuro

2009-01-01

We report on a patient with visual agnosia for line drawings and silhouette pictures following cerebral infarction in the region of the right posterior cerebral artery. The patient retained the ability to recognize real objects and their photographs, and could precisely copy line drawings of objects that she could not name. This case report highlights the importance of clinicians and researchers paying special attention to avoid overlooking agnosia in such cases. The factors that lead to problems in the identification of stimuli other than real objects in agnosic cases are discussed. PMID:19996516

Visual agnosia for line drawings and silhouettes without apparent impairment of real-object recognition: a case report.

PubMed

Hiraoka, Kotaro; Suzuki, Kyoko; Hirayama, Kazumi; Mori, Etsuro

2009-01-01

We report on a patient with visual agnosia for line drawings and silhouette pictures following cerebral infarction in the region of the right posterior cerebral artery. The patient retained the ability to recognize real objects and their photographs, and could precisely copy line drawings of objects that she could not name. This case report highlights the importance of clinicians and researchers paying special attention to avoid overlooking agnosia in such cases. The factors that lead to problems in the identification of stimuli other than real objects in agnosic cases are discussed.

Visual outcomes in treated bacterial keratitis: four years of prospective follow-up.

PubMed

McClintic, Scott M; Prajna, Namperumalsamy V; Srinivasan, Muthiah; Mascarenhas, Jeena; Lalitha, Prajna; Rajaraman, Revathi; Oldenburg, Catherine E; O'Brien, Kieran S; Ray, Kathryn J; Acharya, Nisha R; Lietman, Thomas M; Keenan, Jeremy D

2014-05-02

We described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis. This was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit. We examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71-0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53). Cases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.).

Visual Outcomes in Treated Bacterial Keratitis: Four Years of Prospective Follow-up

PubMed Central

McClintic, Scott M.; Prajna, Namperumalsamy V.; Srinivasan, Muthiah; Mascarenhas, Jeena; Lalitha, Prajna; Rajaraman, Revathi; Oldenburg, Catherine E.; O'Brien, Kieran S.; Ray, Kathryn J.; Acharya, Nisha R.; Lietman, Thomas M.; Keenan, Jeremy D.

2014-01-01

Purpose. We described the change in visual acuity experienced by eyes successfully treated for bacterial keratitis. Methods. This was a prospective cohort study of a subset of study participants who had previously enrolled in the Steroids for Corneal Ulcers Trial (SCUT). All study participants had been diagnosed with culture-proven bacterial keratitis before enrollment in SCUT and subsequently were randomized to adjunctive topical corticosteroids or placebo. During SCUT, we monitored study participants at enrollment, 3 weeks, 3 months, and 12 months. We invited a subset to complete a comprehensive eye examination approximately 4 years after enrollment in SCUT. Certified refractionists assessed best spectacle-corrected visual acuity (BSCVA) using the same protocol at each study visit. Results. We examined 50 SCUT participants at 4 years after enrollment. Among those in this cohort, mean logMAR BSCVA at enrollment was 0.85 (Snellen equivalent, 20/160; 95% confidence interval [CI], 0.71–0.99). On average, visual acuity improved by 2.9 logMAR lines from enrollment to 3 weeks (P < 0.001), 1.2 lines from 3 weeks to 3 months (P = 0.002), and 0.8 lines from 3 to 12 months (P = 0.01). The BSCVA did not change significantly between 12 months and 4 years (0.04-line improvement, P = 0.88). After controlling for visual acuity at enrollment, BSCVA was not significantly different between the corticosteroid and placebo groups at 4 years (P = 0.53). Conclusions. Cases of bacterial keratitis may continue to demonstrate improvements in visual acuity up to 12 months following diagnosis, but further improvements are unlikely. These findings may guide the appropriate timing of surgical intervention in these patients. (ClinicalTrials.gov number, NCT00324168.) PMID:24618327

Effects of angular acceleration on man - Choice reaction time using visual and rotary motion information

NASA Technical Reports Server (NTRS)

Clark, B.; Stewart, J. D.

1974-01-01

This experiment was concerned with the effects of rotary acceleration on choice reaction time (RTc) to the motion of a luminous line on a cathode-ray tube. Specifically, it compared the (RTc) to rotary acceleration alone, visual acceleration alone, and simultaneous, double stimulation by both rotary and visual acceleration. Thirteen airline pilots were rotated about an earth-vertical axis in a precision rotation device while they observed a vertical line. The stimuli were 7 rotary and visual accelerations which were matched for rise time. The pilot responded as quickly as possible by displacing a vertical controller to the right or left. The results showed a decreasing (RTc) with increasing acceleration for all conditions, while the (RTc) to rotary motion alone was substantially longer than for all other conditions. The (RTc) to the double stimulation was significantly longer than that for visual acceleration alone.

Gestalt perception modulates early visual processing.

PubMed

Herrmann, C S; Bosch, V

2001-04-17

We examined whether early visual processing reflects perceptual properties of a stimulus in addition to physical features. We recorded event-related potentials (ERPs) of 13 subjects in a visual classification task. We used four different stimuli which were all composed of four identical elements. One of the stimuli constituted an illusory Kanizsa square, another was composed of the same number of collinear line segments but the elements did not form a Gestalt. In addition, a target and a control stimulus were used which were arranged differently. These stimuli allow us to differentiate the processing of colinear line elements (stimulus features) and illusory figures (perceptual properties). The visual N170 in response to the illusory figure was significantly larger as compared to the other collinear stimulus. This is taken to indicate that the visual N170 reflects cognitive processes of Gestalt perception in addition to attentional processes and physical stimulus properties.

Perception of straightness and parallelism with minimal distance information.

PubMed

Rogers, Brian; Naumenko, Olga

2016-07-01

The ability of human observers to judge the straightness and parallelism of extended lines has been a neglected topic of study since von Helmholtz's initial observations 150 years ago. He showed that there were significant misperceptions of the straightness of extended lines seen in the peripheral visual field. The present study focused on the perception of extended lines (spanning 90° visual angle) that were directly fixated in the visual environment of a planetarium where there was only minimal information about the distance to the lines. Observers were asked to vary the curvature of 1 or more lines until they appeared to be straight and/or parallel, ignoring any perceived curvature in depth. When the horizon between the ground and the sky was visible, the results showed that observers' judgements of the straightness of a single line were significantly biased away from the veridical, great circle locations, and towards equal elevation settings. Similar biases can be seen in the jet trails of aircraft flying across the sky and in Rogers and Anstis's new moon illusion (Perception, 42(Abstract supplement) 18, 2013, 2016). The biasing effect of the horizon was much smaller when observers were asked to judge the straightness and parallelism of 2 or more extended lines. We interpret the results as showing that, in the absence of adequate distance information, observers tend to perceive the projected lines as lying on an approximately equidistant, hemispherical surface and that their judgements of straightness and parallelism are based on the perceived separation of the lines superimposed on that surface.

Visualizing the gravitational lensing and vortex and tendex lines of colliding black holes

NASA Astrophysics Data System (ADS)

Khan, Haroon; Lovelace, Geoffery; SXS Collaboration

2016-03-01

Gravitational waves (GW's) are ripples of space and time that are created when the universe unleashes its violent nature in the presence of strong gravity. Merging black holes (BH) are one of the most promising sources of GW's. In order to detect and physically study the GW's emitted by merging BH with ground based detectors such as Advanced LIGO, we must accurately predict how the waveforms look and behave. This can only be done by numerically simulating BH mergers on supercomputers, because all analytical approximations fail near the time of merger. This poster focuses on using these simulations to answer the question of ``What do merging BH look like''? I will present visualizations made using the Spectral Einstein Code (SpEC) and in particular a raytracing lensing code, developed by the SXS Lensing team, that shows how merging BH bend the light around them. I will also present visualizations of the vortex and tendex lines for a binary BH system, using SpEC. Vortex lines describe how an observer will be twisted by the BH and the tendex lines describe how much an observer would be stretched and squeezed. I am exploring how these lines change with time.

Development of the navigation system for the visually impaired by using white cane.

PubMed

Hirahara, Yoshiaki; Sakurai, Yusuke; Shiidu, Yuriko; Yanashima, Kenji; Magatani, Kazushige

2006-01-01

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 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 there correcting 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 are 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 makes notice to a user by vibration. This system recognizes the color of the line 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.

Holocene alluvial sequences, cumulic soils and fire signatures in the Middle Rio Puerco Basin at Guadalupe Ruin, New Mexico

Treesearch

Charles French; Richard Periman; Linda Scott Cummings; Stephen Hall; Melissa Goodman-Elgar; Julie Boreham

2009-01-01

We describe a geoarchaeological survey of a 5-km reach of the Rio Puerco channel and its tributaries, centered on the Guadalupe Ruin, a pueblo of the late 10th-12th centuries A.D. in north-central New Mexico, with associated pollen, charcoal, micromorphological, and radiocarbon analyses. Severe erosion has drastically bisected the Puerco valley with four primary...

Mesh Generation via Local Bisection Refinement of Triangulated Grids

DTIC Science & Technology

2015-06-01

Science and Technology Organisation DSTO–TR–3095 ABSTRACT This report provides a comprehensive implementation of an unstructured mesh generation method...and Technology Organisation 506 Lorimer St, Fishermans Bend, Victoria 3207, Australia Telephone: 1300 333 362 Facsimile: (03) 9626 7999 c© Commonwealth...their behaviour is critically linked to Maubach’s method and the data structures N and T . The top- level mesh refinement algorithm is also presented

Increased Bisecting N-Acetylglucosamine and Decreased Branched Chain Glycans of N-linked Glycoproteins in Expressed Prostatic Secretions Associated with Prostate Cancer Progression

PubMed Central

Nyalwidhe, Julius O.; Betesh, Lucy R.; Powers, Thomas W.; Jones, E. Ellen; White, Krista Y.; Burch, Tanya C.; Brooks, Jasmin; Watson, Megan T.; Lance, Raymond S.; Troyer, Dean A.; Semmes, O. John; Mehta, Anand; Drake, Richard R.

2013-01-01

Purpose Using prostatic fluids rich in glycoproteins like prostate specific antigen (PSA) and prostatic acid phosphatase (PAP) , the goal of this study was to identify the structural types and relative abundance of glycans associated with prostate cancer status for subsequent use in emerging mass spectrometry-based glycopeptide analysis platforms. Experimental Design A series of pooled samples of expressed prostatic secretions (EPS) and exosomes reflecting different stages of prostate cancer disease were used for N-linked glycan profiling by three complementary methods, MALDI-TOF profiling, normal-phase HPLC separation, and triple quadropole MS analysis of PAP glycopeptides. Results Glycan profiling of N-linked glycans from different EPS fluids indicated a global decrease in larger branched tri- and tetra-antennary glycans. Differential exoglycosidase treatments indicated a substantial increase in bisecting N-acetylglucosamines correlated with disease severity. A triple quadrupole MS analysis of the N-linked glycopeptides sites from PAP in aggressive prostate cancer pools was done to cross-reference with the glycan profiling data. Conclusion and clinical relevance Changes in glycosylation as detected in EPS fluids reflect the clinical status of prostate cancer. Defining these molecular signatures at the glycopeptide level in individual samples could improve current approaches of diagnosis and prognosis. PMID:23775902

Enhanced auditory spatial localization in blind echolocators.

PubMed

Vercillo, Tiziana; Milne, Jennifer L; Gori, Monica; Goodale, Melvyn A

2015-01-01

Echolocation is the extraordinary ability to represent the external environment by using reflected sound waves from self-generated auditory pulses. Blind human expert echolocators show extremely precise spatial acuity and high accuracy in determining the shape and motion of objects by using echoes. In the current study, we investigated whether or not the use of echolocation would improve the representation of auditory space, which is severely compromised in congenitally blind individuals (Gori et al., 2014). The performance of three blind expert echolocators was compared to that of 6 blind non-echolocators and 11 sighted participants. Two tasks were performed: (1) a space bisection task in which participants judged whether the second of a sequence of three sounds was closer in space to the first or the third sound and (2) a minimum audible angle task in which participants reported which of two sounds presented successively was located more to the right. The blind non-echolocating group showed a severe impairment only in the space bisection task compared to the sighted group. Remarkably, the three blind expert echolocators performed both spatial tasks with similar or even better precision and accuracy than the sighted group. These results suggest that echolocation may improve the general sense of auditory space, most likely through a process of sensory calibration. Copyright © 2014 Elsevier Ltd. All rights reserved.

Orthogonal recursive bisection as data decomposition strategy for massively parallel cardiac simulations.

PubMed

Reumann, Matthias; Fitch, Blake G; Rayshubskiy, Aleksandr; Pitman, Michael C; Rice, John J

2011-06-01

We present the orthogonal recursive bisection algorithm that hierarchically segments the anatomical model structure into subvolumes that are distributed to cores. The anatomy is derived from the Visible Human Project, with electrophysiology based on the FitzHugh-Nagumo (FHN) and ten Tusscher (TT04) models with monodomain diffusion. Benchmark simulations with up to 16,384 and 32,768 cores on IBM Blue Gene/P and L supercomputers for both FHN and TT04 results show good load balancing with almost perfect speedup factors that are close to linear with the number of cores. Hence, strong scaling is demonstrated. With 32,768 cores, a 1000 ms simulation of full heart beat requires about 6.5 min of wall clock time for a simulation of the FHN model. For the largest machine partitions, the simulations execute at a rate of 0.548 s (BG/P) and 0.394 s (BG/L) of wall clock time per 1 ms of simulation time. To our knowledge, these simulations show strong scaling to substantially higher numbers of cores than reported previously for organ-level simulation of the heart, thus significantly reducing run times. The ability to reduce runtimes could play a critical role in enabling wider use of cardiac models in research and clinical applications.

CSF N-glycoproteomics for early diagnosis in Alzheimer's disease.

PubMed

Palmigiano, Angelo; Barone, Rita; Sturiale, Luisa; Sanfilippo, Cristina; Bua, Rosaria Ornella; Romeo, Donata Agata; Messina, Angela; Capuana, Maria Luisa; Maci, Tiziana; Le Pira, Francesco; Zappia, Mario; Garozzo, Domenico

2016-01-10

This work aims at exploring the human CSF (Cerebrospinal fluid) N-glycome by MALDI MS techniques, in order to assess specific glycosylation pattern(s) in patients with Alzheimer's disease (n:24) and in subjects with mild cognitive impairment (MCI) (n:11), these last as potential AD patients at a pre-dementia stage. For comparison, 21 healthy controls were studied. We identified a group of AD and MCI subjects (about 40-50% of the studied sample) showing significant alteration of CSF N-glycome profiling, consisting of a decrease in the overall sialylation degree and an increase in species bearing bisecting GlcNAc. Noteworthy, all the MCI patients that converted to AD within the clinical follow-up, had an abnormal CSF glycosylation profile. Based on the studied cohort, CSF glycosylation changes may occur before an AD clinical onset. Previous studies specifically focused on the key role of glycosyltransferase GnT-III on AD-pathogenesis, addressing the patho-mechanism to specific sugar modification of BACE-1 glycoprotein with bisecting GlcNAc. Our patients addressed protein N-glycosylation changes at an early phase of the whole biomolecular misregulation on AD, pointing to CSF N-glycome analyses as promising tool to enhance early detection of AD and also suggesting alternative therapeutics target molecules, such as specific glyco-enzymes. Copyright © 2015 Elsevier B.V. All rights reserved.

Oligosaccharide composition is similar in drusen and dense deposits in membranoproliferative glomerulonephritis type II.

PubMed

D'souza, Yvonne B; Jones, Carolyn J P; Short, Colin D; Roberts, Ian S D; Bonshek, Richard E

2009-04-01

Drusen are a feature of age-related macular degeneration (AMD). Lesions similar in appearance to drusen are also found in the fundi of patients with membranoproliferative glomerulonephritis type II (dense deposit disease, DDD). The lamina densa of the glomerular basement membrane, in DDD, is transformed into an electron-dense structure by deposition of microscopically homogeneous material. Our study sought to compare the saccharide composition of drusen and dense deposits in the formalin-fixed, paraffin-embedded tissue from the eye and kidney. Six eye specimens were obtained from patients diagnosed with AMD but another eye was obtained from a patient with partial lipodystrophy, who died after renal failure presumably because of DDD. The kidney specimens were from three biopsy-proven cases of DDD. Glycosylation patterns were measured by the binding of 19 biotinylated lectins before and after neuraminidase pre-treatment. High mannose, bi/tri-antennary non-bisected and bisected complex N-glycan, N-acetyl glucosamine, galactose, and sialic acid residues were found in both drusen and dense deposits. Treatment with neuraminidase exposed subterminal galactose in both sites and sparse N-acetyl galactosamine residues in drusen alone. Our study found similar pathologic oligosaccharide structures in the eye and kidney, suggesting that drusen may be a common end result of retinal and glomerular disease.

Parallel solution of the symmetric tridiagonal eigenproblem. Research report

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

Jessup, E.R.

1989-10-01

This thesis discusses methods for computing all eigenvalues and eigenvectors of a symmetric tridiagonal matrix on a distributed-memory Multiple Instruction, Multiple Data multiprocessor. Only those techniques having the potential for both high numerical accuracy and significant large-grained parallelism are investigated. These include the QL method or Cuppen's divide and conquer method based on rank-one updating to compute both eigenvalues and eigenvectors, bisection to determine eigenvalues and inverse iteration to compute eigenvectors. To begin, the methods are compared with respect to computation time, communication time, parallel speed up, and accuracy. Experiments on an IPSC hypercube multiprocessor reveal that Cuppen's method ismore » the most accurate approach, but bisection with inverse iteration is the fastest and most parallel. Because the accuracy of the latter combination is determined by the quality of the computed eigenvectors, the factors influencing the accuracy of inverse iteration are examined. This includes, in part, statistical analysis of the effect of a starting vector with random components. These results are used to develop an implementation of inverse iteration producing eigenvectors with lower residual error and better orthogonality than those generated by the EISPACK routine TINVIT. This thesis concludes with adaptions of methods for the symmetric tridiagonal eigenproblem to the related problem of computing the singular value decomposition (SVD) of a bidiagonal matrix.« less

Parallel solution of the symmetric tridiagonal eigenproblem

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

Jessup, E.R.

1989-01-01

This thesis discusses methods for computing all eigenvalues and eigenvectors of a symmetric tridiagonal matrix on a distributed memory MIMD multiprocessor. Only those techniques having the potential for both high numerical accuracy and significant large-grained parallelism are investigated. These include the QL method or Cuppen's divide and conquer method based on rank-one updating to compute both eigenvalues and eigenvectors, bisection to determine eigenvalues, and inverse iteration to compute eigenvectors. To begin, the methods are compared with respect to computation time, communication time, parallel speedup, and accuracy. Experiments on an iPSC hyper-cube multiprocessor reveal that Cuppen's method is the most accuratemore » approach, but bisection with inverse iteration is the fastest and most parallel. Because the accuracy of the latter combination is determined by the quality of the computed eigenvectors, the factors influencing the accuracy of inverse iteration are examined. This includes, in part, statistical analysis of the effects of a starting vector with random components. These results are used to develop an implementation of inverse iteration producing eigenvectors with lower residual error and better orthogonality than those generated by the EISPACK routine TINVIT. This thesis concludes with adaptations of methods for the symmetric tridiagonal eigenproblem to the related problem of computing the singular value decomposition (SVD) of a bidiagonal matrix.« less

Vasopressin-induced constriction of the isolated rat occipital artery is segment-dependent

PubMed Central

Chelko, Stephen P.; Schmiedt, Chad W.; Lewis, Tristan H.; Lewis, Stephen J.; Robertson, Tom P.

2014-01-01

Background Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. Methods OA were isolated and bisected into proximal and distal segments, relative to the external carotid artery. Results Bisection, highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist, were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-HT and the 5-HT2 receptor agonist than proximal segments. AT2, V2 and 5-HT1B/1D receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. Conclusion The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors, and are dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration response curve retained this unique segmental difference and therefore we hypothesize this may be a pathophysiological response in the regulation of blood flow through the OA. PMID:24192548

Motor adaptation in complex sports - the influence of visual context information on the adaptation of the three-point shot to altered task demands in expert basketball players.

PubMed

Stöckel, Tino; Fries, Udo

2013-01-01

We examined the influence of visual context information on skilled motor behaviour and motor adaptation in basketball. The rules of basketball in Europe have recently changed, such that that the distance for three-point shots increased from 6.25 m to 6.75 m. As such, we tested the extent to which basketball experts can adapt to the longer distance when a) only the unfamiliar, new three-point line was provided as floor markings (NL group), or b) the familiar, old three-point line was provided in addition to the new floor markings (OL group). In the present study 20 expert basketball players performed 40 three-point shots from 6.25 m and 40 shots from 6.75 m. We assessed the percentage of hits and analysed the landing position of the ball. Results showed better adaptation of throwing performance to the longer distance when the old three-point line was provided as a visual landmark, compared to when only the new three-point line was provided. We hypothesise that the three-point line delivered relevant information needed to successfully adapt to the greater distance in the OL group, whereas it disturbed performance and ability to adapt in the NL group. The importance of visual landmarks on motor adaptation in basketball throwing is discussed relative to the influence of other information sources (i.e. angle of elevation relative to the basket) and sport practice.

Study of Pattern of Change in Handwriting Class Characters with Different Grades of Myopia.

PubMed

Hedge, Shruti Prabhat; Dayanidhi, Vijay Kautilya; Sriram

2015-12-01

Handwriting is a visuo-motor skill highly dependent on visual skills. Any defect in the visual inputs could affect a change in the handwriting. Understanding the variation in handwriting characters caused by visual acuity change can help in identifying learning disabilities in children and also assess the disability in elderly. In our study we try to analyse and catalogue these changes in the handwriting of a person. The study was conducted among 100 subjects having normal visual acuity. They were asked to perform a set of writing tasks, after which the same tasks were repeated after inducing different grades of myopia. Changes in the handwriting class characters were analysed and compared in all grades of myopia. In the study it was found that the letter size, pastiosity, word omissions, inability to stay on line all increase with changes in visual acuity. However these finding are not proportional to the grade of myopia. From the findings of the study it can be concluded that myopia significantly influences the handwriting and any change in visual acuity would induce corresponding changes in handwriting. There is increase in letter size, pastiosity where as the ability to stay on line and space between the lines decrease in different grades of myopia. The changes are not linear and cannot be used to predict the grade of myopia but can be used as parameters suggestive of refractive error.

Visual function after strontium-90 plaque irradiation in patients with age-related subfoveal choroidal neovascularization.

PubMed

Jaakkola, A; Heikkonen, J; Tarkkanen, A; Immonen, I

1999-02-01

To report 2-year visual and angiographic results in eyes treated with strontium plaque irradiation for subfoveal choroidal neovascular membranes (CNVM) in age-related macular degeneration. Twenty eyes with recent subfoveal CNVM were treated with local irradiation. The impact of the treatment on visual function was evaluated by visual acuity, contrast sensitivity and reading speed testing. At 12 months visual acuity had improved or remained the same in 9/ 20 eyes (45%). At 24 months visual acuity was stable in 5/18 eyes (28%). Eyes with signs of CNVM regression (13/18, 72%) lost a mean of 3.3 lines, but eyes with recurrent CNVM lost a mean of 5.1 lines of vision. The mean contrast sensitivity was better in the irradiated eyes than in the fellow eyes with late age-related macular degeneration at 24 months. Six of 17 irradiated eyes (35%) could read at least some words at 24 months. Visual function decreases in patients treated with strontium irradiation, but less in eyes showing regression of the CNVM than in eyes with further growth of the CNVM.

Fitting the Jigsaw of Citation: Information Visualization in Domain Analysis.

ERIC Educational Resources Information Center

Chen, Chaomei; Paul, Ray J.; O'Keefe, Bob

2001-01-01

Discusses the role of information visualization in modeling and representing intellectual structures associated with scientific disciplines and visualizes the domain of computer graphics based on bibliographic data from author cocitation patterns. Highlights include author cocitation maps, citation time lines, animation of a high-dimensional…

Nondestructive Testing of Overhead Transmission LINES—NUMERICAL and Experimental Investigation

NASA Astrophysics Data System (ADS)

Kulkarni, S.; Hurlebaus, S.

2009-03-01

Overhead transmission lines are periodically inspected using both on-ground and helicopter-aided visual inspection. Factors including sun glare, cloud cover, close proximity to power lines and the rapidly changing visual circumstances make airborne inspection of power lines a particularly hazardous task. In this study, a finite element model is developed that can be used to create the theoretical dispersion curves of an overhead transmission line. The numerical results are then verified with experimental test using a non-contact and broadband laser detection technique. The methodology developed in this study can be further extended to a continuous monitoring system and be applied to other cable monitoring applications, such as bridge cable monitoring, which would otherwise put human inspectors at risk.

The GRIDView Visualization Package

NASA Astrophysics Data System (ADS)

Kent, B. R.

2011-07-01

Large three-dimensional data cubes, catalogs, and spectral line archives are increasingly important elements of the data discovery process in astronomy. Visualization of large data volumes is of vital importance for the success of large spectral line surveys. Examples of data reduction utilizing the GRIDView software package are shown. The package allows users to manipulate data cubes, extract spectral profiles, and measure line properties. The package and included graphical user interfaces (GUIs) are designed with pipeline infrastructure in mind. The software has been used with great success analyzing spectral line and continuum data sets obtained from large radio survey collaborations. The tools are also important for multi-wavelength cross-correlation studies and incorporate Virtual Observatory client applications for overlaying database information in real time as cubes are examined by users.

Embryo-specific expression of a visual reporter gene as a selection system for citrus transformation

PubMed Central

Zambon, Flavia T.; Erpen, Lígia; Soriano, Leonardo; Grosser, Jude

2018-01-01

The embryo-specific Dc3 gene promoter driving the VvMybA1 anthocyanin regulatory gene was used to develop a visual selection system for the genetic transformation of citrus. Agrobacterium-mediated transformation of cell suspension cultures resulted in the production of purple transgenic somatic embryos that could be easily separated from the green non-transgenic embryos. The somatic embryos produced phenotypically normal plants devoid of any visual purple coloration. These results were also confirmed using protoplast transformation. There was minimal gene expression in unstressed one-year-old transgenic lines. Cold and drought stress did not have any effect on gene expression, while exogenous ABA and NaCl application resulted in a minor change in gene expression in several transgenic lines. When gas exchange was measured in intact leaves, the transgenic lines were similar to controls under the same environment. Our results provide conclusive evidence for the utilization of a plant-derived, embryo-specific visual reporter system for the genetic transformation of citrus. Such a system could aid in the development of an all-plant, consumer-friendly GM citrus tree. PMID:29293649

Simulation services and analysis tools at the CCMC to study multi-scale structure and dynamics of Earth's magnetopause

NASA Astrophysics Data System (ADS)

Kuznetsova, M. M.; Liu, Y. H.; Rastaetter, L.; Pembroke, A. D.; Chen, L. J.; Hesse, M.; Glocer, A.; Komar, C. M.; Dorelli, J.; Roytershteyn, V.

2016-12-01

The presentation will provide overview of new tools, services and models implemented at the Community Coordinated Modeling Center (CCMC) to facilitate MMS dayside results analysis. We will provide updates on implementation of Particle-in-Cell (PIC) simulations at the CCMC and opportunities for on-line visualization and analysis of results of PIC simulations of asymmetric magnetic reconnection for different guide fields and boundary conditions. Fields, plasma parameters, particle distribution moments as well as particle distribution functions calculated in selected regions of the vicinity of reconnection sites can be analyzed through the web-based interactive visualization system. In addition there are options to request distribution functions in user selected regions of interest and to fly through simulated magnetic reconnection configurations and a map of distributions to facilitate comparisons with observations. A broad collection of global magnetosphere models hosted at the CCMC provide opportunity to put MMS observations and local PIC simulations into global context. We recently implemented the RECON-X post processing tool (Glocer et al, 2016) which allows users to determine the location of separator surface around closed field lines and between open field lines and solar wind field lines. The tool also finds the separatrix line where the two surfaces touch and positions of magnetic nulls. The surfaces and the separatrix line can be visualized relative to satellite positions in the dayside magnetosphere using an interactive HTML-5 visualization for each time step processed. To validate global magnetosphere models' capability to simulate locations of dayside magnetosphere boundaries we will analyze the proximity of MMS to simulated separatrix locations for a set of MMS diffusion region crossing events.

Overlap of movement planning and movement execution reduces reaction time.

PubMed

Orban de Xivry, Jean-Jacques; Legrain, Valéry; Lefèvre, Philippe

2017-01-01

Motor planning is the process of preparing the appropriate motor commands in order to achieve a goal. This process has largely been thought to occur before movement onset and traditionally has been associated with reaction time. However, in a virtual line bisection task we observed an overlap between movement planning and execution. In this task performed with a robotic manipulandum, we observed that participants (n = 30) made straight movements when the line was in front of them (near target) but often made curved movements when the same target was moved sideways (far target, which had the same orientation) in such a way that they crossed the line perpendicular to its orientation. Unexpectedly, movements to the far targets had shorter reaction times than movements to the near targets (mean difference: 32 ms, SE: 5 ms, max: 104 ms). In addition, the curvature of the movement modulated reaction time. A larger increase in movement curvature from the near to the far target was associated with a larger reduction in reaction time. These highly curved movements started with a transport phase during which accuracy demands were not taken into account. We conclude that an accuracy demand imposes a reaction time penalty if processed before movement onset. This penalty is reduced if the start of the movement consists of a transport phase and if the movement plan can be refined with respect to accuracy demands later in the movement, hence demonstrating an overlap between movement planning and execution. In the planning of a movement, the brain has the opportunity to delay the incorporation of accuracy requirements of the motor plan in order to reduce the reaction time by up to 100 ms (average: 32 ms). Such shortening of reaction time is observed here when the first phase of the movement consists of a transport phase. This forces us to reconsider the hypothesis that motor plans are fully defined before movement onset. Copyright © 2017 the American Physiological Society.

Overlap of movement planning and movement execution reduces reaction time

PubMed Central

Legrain, Valéry; Lefèvre, Philippe

2016-01-01

Motor planning is the process of preparing the appropriate motor commands in order to achieve a goal. This process has largely been thought to occur before movement onset and traditionally has been associated with reaction time. However, in a virtual line bisection task we observed an overlap between movement planning and execution. In this task performed with a robotic manipulandum, we observed that participants (n = 30) made straight movements when the line was in front of them (near target) but often made curved movements when the same target was moved sideways (far target, which had the same orientation) in such a way that they crossed the line perpendicular to its orientation. Unexpectedly, movements to the far targets had shorter reaction times than movements to the near targets (mean difference: 32 ms, SE: 5 ms, max: 104 ms). In addition, the curvature of the movement modulated reaction time. A larger increase in movement curvature from the near to the far target was associated with a larger reduction in reaction time. These highly curved movements started with a transport phase during which accuracy demands were not taken into account. We conclude that an accuracy demand imposes a reaction time penalty if processed before movement onset. This penalty is reduced if the start of the movement consists of a transport phase and if the movement plan can be refined with respect to accuracy demands later in the movement, hence demonstrating an overlap between movement planning and execution. NEW & NOTEWORTHY In the planning of a movement, the brain has the opportunity to delay the incorporation of accuracy requirements of the motor plan in order to reduce the reaction time by up to 100 ms (average: 32 ms). Such shortening of reaction time is observed here when the first phase of the movement consists of a transport phase. This forces us to reconsider the hypothesis that motor plans are fully defined before movement onset. PMID:27733598

Method for measuring visual resolution at the retinal level.

PubMed

Liang, J; Westheimer, G

1993-08-01

To measure the intrinsic resolving capacity of the retinal and neural levels of vision, we devised a method that creates two lines with controllable contrast on the retina. The line separation can be varied at will, down to values below those achievable with conventional optical techniques. Implementation of the method with use of a He-Ne laser leads to a procedure that permits analysis of the performance of the human visual apparatus.

Evidence for impairments in using static line drawings of eye gaze cues to orient visual-spatial attention in children with high functioning autism.

PubMed

Goldberg, Melissa C; Mostow, Allison J; Vecera, Shaun P; Larson, Jennifer C Gidley; Mostofsky, Stewart H; Mahone, E Mark; Denckla, Martha B

2008-09-01

We examined the ability to use static line drawings of eye gaze cues to orient visual-spatial attention in children with high functioning autism (HFA) compared to typically developing children (TD). The task was organized such that on valid trials, gaze cues were directed toward the same spatial location as the appearance of an upcoming target, while on invalid trials gaze cues were directed to an opposite location. Unlike TD children, children with HFA showed no advantage in reaction time (RT) on valid trials compared to invalid trials (i.e., no significant validity effect). The two stimulus onset asynchronies (200 ms, 700 ms) did not differentially affect these findings. The results suggest that children with HFA show impairments in utilizing static line drawings of gaze cues to orient visual-spatial attention.

The sensory basis of rheotaxis in turbulent flow

NASA Astrophysics Data System (ADS)

Elder, John P.

Rheotaxis is a robust, multisensory behavior with many potential benefits for fish and other aquatic animals, yet the influence of different fluvial conditions on rheotactic performance and its sensory basis is still poorly understood. Here, we examine the role that vision and the lateral line play in the rheotactic behavior of a stream-dwelling species (Mexican tetra, Astyanax mexicanus) under both rectilinear and turbulent flow conditions. Turbulence enhanced overall rheotactic strength and lowered the flow speed at which rheotaxis was initiated; this effect did not depend on the availability of either visual or lateral line information. Compared to fish without access to visual information, fish with access to visual information exhibited increased levels of positional stability and as a result, increased levels of rheotactic accuracy. No disruption in rheotactic performance was found when the lateral line was disabled, suggesting that this sensory system is not necessary for either rheotaxis or turbulence detection under the conditions of this study.

Success in Architecture: Handedness and/or Visual Thinking.

ERIC Educational Resources Information Center

Peterson, John M.; Lansky, Leonard M.

1980-01-01

Some data on sex and handedness in relation to academic predictors and success in architectural education were reexamined. The new variable was the notion of visual thinking, measured by the manner, "visually" or "cognitively," of executing a simple line drawing. As expected, significant differences appeared between persons using these modes.…

Observations of solar-cell metallization corrosion

NASA Technical Reports Server (NTRS)

Mon, G. R.

1983-01-01

The Engineering Sciences Area of the Jet Propulsion Laboratory (JPL) Flat-Plate Solar Array Project is performing long term environmental tests on photovoltaic modules at Wyle Laboratories in Huntsville, Alabama. Some modules have been exposed to 85 C/85% RH and 40 C/93% RH for up to 280 days. Other modules undergoing temperature-only exposures ( 3% RH) at 85 C and 100 C have been tested for more than 180 days. At least two modules of each design type are exposed to each environment - one with, and the other without a 100-mA forward bias. Degradation is both visually observed and electrically monitored. Visual observations of changes in appearance are recorded at each inspection time. Significant visual observations relating to metallization corrosion (and/or metallization-induced corrosion) include discoloration (yellowing and browning) of grid lines, migration of grid line material into the encapsulation (blossoming), the appearance of rainbow-like diffraction patterns on the grid lines, and brown spots on collectors and grid lines. All of these observations were recorded for electrically biased modules in the 280-day tests with humidity.

ACHP | News | ACHP Issue Spotlight: Transmission Lines in the West

Science.gov Websites

effects. Some historic properties are affected by several of these lines, and some lines have multiple parts of Idaho and Montana. There are potential effects to a number of important historic properties impact, visual effects of this transmission line, will be approximated through "backsighted analysis

Research on optimal DEM cell size for 3D visualization of loess terraces

NASA Astrophysics Data System (ADS)

Zhao, Weidong; Tang, Guo'an; Ji, Bin; Ma, Lei

2009-10-01

In order to represent the complex artificial terrains like loess terraces in Shanxi Province in northwest China, a new 3D visual method namely Terraces Elevation Incremental Visual Method (TEIVM) is put forth by the authors. 406 elevation points and 14 enclosed constrained lines are sampled according to the TIN-based Sampling Method (TSM) and DEM Elevation Points and Lines Classification (DEPLC). The elevation points and constrained lines are used to construct Constrained Delaunay Triangulated Irregular Networks (CD-TINs) of the loess terraces. In order to visualize the loess terraces well by use of optimal combination of cell size and Elevation Increment Value (EIV), the CD-TINs is converted to Grid-based DEM (G-DEM) by use of different combination of cell size and EIV with linear interpolating method called Bilinear Interpolation Method (BIM). Our case study shows that the new visual method can visualize the loess terraces steps very well when the combination of cell size and EIV is reasonable. The optimal combination is that the cell size is 1 m and the EIV is 6 m. Results of case study also show that the cell size should be at least smaller than half of both the terraces average width and the average vertical offset of terraces steps for representing the planar shapes of the terraces surfaces and steps well, while the EIV also should be larger than 4.6 times of the terraces average height. The TEIVM and results above is of great significance to the highly refined visualization of artificial terrains like loess terraces.

Neural Correlates of Subjective Awareness for Natural Scene Categorization of Color Photographs and Line-Drawings.

PubMed

Fu, Qiufang; Liu, Yong-Jin; Dienes, Zoltan; Wu, Jianhui; Chen, Wenfeng; Fu, Xiaolan

2017-01-01

It remains controversial whether visual awareness is correlated with early activation indicated by VAN (visual awareness negativity), as the recurrent process hypothesis theory proposes, or with later activation indicated by P3 or LP (late positive), as suggested by global workspace theories. To address this issue, a backward masking task was adopted, in which participants were first asked to categorize natural scenes of color photographs and line-drawings and then to rate the clarity of their visual experience on a Perceptual Awareness Scale (PAS). The interstimulus interval between the scene and the mask was manipulated. The behavioral results showed that categorization accuracy increased with PAS ratings for both color photographs and line-drawings, with no difference in accuracy between the two types of images for each rating, indicating that the experience rating reflected visibility. Importantly, the event-related potential (ERP) results revealed that for correct trials, the early posterior N1 and anterior P2 components changed with the PAS ratings for color photographs, but did not vary with the PAS ratings for line-drawings, indicating that the N1 and P2 do not always correlate with subjective visual awareness. Moreover, for both types of images, the anterior N2 and posterior VAN changed with the PAS ratings in a linear way, while the LP changed with the PAS ratings in a non-linear way, suggesting that these components relate to different types of subjective awareness. The results reconcile the apparently contradictory predictions of different theories and help to resolve the current debate on neural correlates of visual awareness.

Neural Correlates of Subjective Awareness for Natural Scene Categorization of Color Photographs and Line-Drawings

PubMed Central

Fu, Qiufang; Liu, Yong-Jin; Dienes, Zoltan; Wu, Jianhui; Chen, Wenfeng; Fu, Xiaolan

2017-01-01

It remains controversial whether visual awareness is correlated with early activation indicated by VAN (visual awareness negativity), as the recurrent process hypothesis theory proposes, or with later activation indicated by P3 or LP (late positive), as suggested by global workspace theories. To address this issue, a backward masking task was adopted, in which participants were first asked to categorize natural scenes of color photographs and line-drawings and then to rate the clarity of their visual experience on a Perceptual Awareness Scale (PAS). The interstimulus interval between the scene and the mask was manipulated. The behavioral results showed that categorization accuracy increased with PAS ratings for both color photographs and line-drawings, with no difference in accuracy between the two types of images for each rating, indicating that the experience rating reflected visibility. Importantly, the event-related potential (ERP) results revealed that for correct trials, the early posterior N1 and anterior P2 components changed with the PAS ratings for color photographs, but did not vary with the PAS ratings for line-drawings, indicating that the N1 and P2 do not always correlate with subjective visual awareness. Moreover, for both types of images, the anterior N2 and posterior VAN changed with the PAS ratings in a linear way, while the LP changed with the PAS ratings in a non-linear way, suggesting that these components relate to different types of subjective awareness. The results reconcile the apparently contradictory predictions of different theories and help to resolve the current debate on neural correlates of visual awareness. PMID:28261141

Vision Status in Older Adults: The Brazilian Amazon Region Eye Survey.

PubMed

Salomão, Solange R; Berezovsky, Adriana; Furtado, João M; Fernandes, Arthur G; Muñoz, Sergio; Cavascan, Nívea N; Cypel, Marcela C; Cunha, Cristina C; Vasconcelos, Galton C; Mitsuhiro, Márcia R K H; Sacai, Paula Y; Campos, Mauro; Morales, Paulo H A; Cohen, Marcos J; Cohen, Jacob M; Watanabe, Sung E S; Belfort, Rubens

2018-01-17

Older adults living in remote areas with limited access to health services are at higher risk to develop visual impairment and blindness. We conducted a population-based survey to determine the vision status in subjects 45 years of age and older from urban and rural areas of Parintins city, Brazilian Amazon Region. Participants underwent ophthalmic examination, including uncorrected (UCVA), presenting (PVA) and best-corrected visual acuity (BCVA). Vision status was described as lines of visual acuity (VA) impairment and lines of VA improvement from UCVA to BCVA and from PVA to BCVA in the better-seeing eye. A total of 2384 subjects were enumerated, 2041 (85.6%) were examined, with reliable VA measurements obtained from 2025 participants. Vision status in lines of VA impairment was (mean ± standard deviation): 3.44 ± 3.53 for UCVA, 2.85 ± 3.52 for PVA and 1.50 ± 3.51 for BCVA. Female gender, older age and lower education were associated with ≥6 lines of UCVA impairment. Lines of improvement ≥3 was found in 626 (30.9%) participants and associated with female gender and rural residency. In conclusion, a third of participants could have at least three lines of VA improvement with proper refraction. Strategies to improve access to eye care and affordable glasses are needed.

EventSlider User Manual

DTIC Science & Technology

2016-09-01

is a Windows Presentation Foundation (WPF) control developed using the .NET framework in Microsoft Visual Studio. As a WPF control, it can be used in...any WPF application as a graphical visual element. The purpose of the control is to visually display time-related events as vertical lines on a...available on the control. 15. SUBJECT TERMS Windows Presentation Foundation, WPF, control, C#, .NET framework, Microsoft Visual Studio 16. SECURITY

Louisville, KY, USA

NASA Technical Reports Server (NTRS)

1973-01-01

The meandering Ohio River bisecting this image is the border between Kentucky and Indiana. Louisville, KY (38.5N, 86.0W) on the south shore, is the main city seen in this predominately agricultural region where much of the native hardwood forests have been preserved in the hilly terrain. The main crops in this region include corn, alfalfa, wheat and soybeans. The dark rectangle in south Indiana near the river is The U.S. Army's Jefferson Proving Ground.

Multiple groups of orientation-selective visual mechanisms underlying rapid orientated-line detection.

PubMed Central

Foster, D H; Westland, S

1998-01-01

Visual search for an edge or line element differing in orientation from a background of other edge or line elements can be performed rapidly and effortlessly. In this study, based on psychophysical measurements with ten human observers, threshold values of the angle between a target and background line elements were obtained as functions of background-element orientation, in brief masked displays. A repeated-loess analysis of the threshold functions suggested the existence of several groups of orientation-selective mechanisms contributing to rapid orientated-line detection; specifically, coarse, intermediate and fine mechanisms with preferred orientations spaced at angles of approximately 90 degrees, 35 degrees, and 10 degrees-25 degrees, respectively. The preferred orientations of coarse and some intermediate mechanisms coincided with the vertical or horizontal of the frontoparallel plane, but the preferred orientations of fine mechanisms varied randomly from observer to observer, possibly reflecting individual variations in neuronal sampling characteristics. PMID:9753784

Representation of numerosity in posterior parietal cortex

PubMed Central

Roitman, Jamie D.; Brannon, Elizabeth M.; Platt, Michael L.

2012-01-01

Humans and animals appear to share a similar representation of number as an analog magnitude on an internal, subjective scale. Neurological and neurophysiological data suggest that posterior parietal cortex (PPC) is a critical component of the circuits that form the basis of numerical abilities in humans. Patients with parietal lesions are impaired in their ability to access the deep meaning of numbers. Acalculiac patients with inferior parietal damage often have difficulty performing arithmetic (2 + 4?) or number bisection (what is between 3 and 5?) tasks, but are able to recite multiplication tables and read or write numerals. Functional imaging studies of neurologically intact humans performing subtraction, number comparison, and non-verbal magnitude comparison tasks show activity in areas within the intraparietal sulcus (IPS). Taken together, clinical cases and imaging studies support a critical role for parietal cortex in the mental manipulation of numerical quantities. Further, responses of single PPC neurons in non-human primates are sensitive to the numerosity of visual stimuli independent of low-level stimulus qualities. When monkeys are trained to make explicit judgments about the numerical value of such stimuli, PPC neurons encode their cardinal numerical value; without such training PPC neurons appear to encode numerical magnitude in an analog fashion. Here we suggest that the spatial and integrative properties of PPC neurons contribute to their critical role in numerical cognition. PMID:22666194

High-Spatial-Resolution OH and CH2O PLIF Visualization in a Dual-Mode Scramjet Combustor

NASA Technical Reports Server (NTRS)

Geipel, Clayton M.

2017-01-01

A high-spatial-resolution planar laser-induced fluorescence (PLIF) imaging system was constructed and used to image a cavity-stabilized, premixed ethylene-air flame. The flame was created within a continuous flow, electrically-heated supersonic combustion facility consisting of a Mach 2 nozzle, an isolator with flush-wall fuel injectors, a combustor with a cavity flameholder of height 9 mm and optical access, and an extender. Tests were conducted at total temperature 1200 K, total pressure 300 kPa, equivalence ratio near 0.4 in the combustor, and Mach number near 0.6 in the combustor. A frequency-doubled Nd:YAG laser pumped a dye laser, which produced light at 283.55 nm. The beam was shaped into a light sheet with full width half-maximum 25 microns, which illuminated a streamwise plane that bisected the cavity. An intensified camera system imaged OH in this plane with a square 6.67 mm field of view and in-plane resolution 39 microns. Images were taken between the backward-facing step and 120 mm downstream of the step. OH structures as small as 110 microns were observed. CH2O was excited using 352.48 nm light; the smallest observed CH2O structures were approximately 200 microns wide. Approximately 15,000 images per species were processed and used to compute composite images.

A navigation system for the visually impaired an intelligent white cane.

PubMed

Fukasawa, A Jin; Magatani, Kazusihge

2012-01-01

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, this sensor senses a color of navigation line and the system informs the visually impaired that he/she is walking along the navigation line by vibration. This color recognition system is controlled by a one-chip microprocessor. RFID tags and a receiver for these tags are used in the map information system. RFID tags are set on the colored navigation line. An antenna for RFID tags and a tag receiver are also installed on a white cane. The receiver receives the area information as a tag-number and notifies map information to the user by mp3 formatted pre-recorded voice. And now, we developed the direction identification technique. Using this technique, we can detect a user's walking direction. A triaxiality acceleration sensor is used in this system. Three normal subjects who were blindfolded with an eye mask were tested with our developed navigation system. All of them were able to walk along the navigation line perfectly. We think that the performance of the system is good. Therefore, our system will be extremely valuable in supporting the activities of the visually impaired.

A simplified ingestion procedure for esophageal capsule endoscopy: initial evaluation in healthy volunteers.

PubMed

Gralnek, I M; Rabinovitz, R; Afik, D; Eliakim, R

2006-09-01

Initial studies on esophageal capsule endoscopy (PillCam ESO) reported excellent sensitivity and specificity, but these were followed by mixed results in several subsequent studies, probably due to deviations from the recommended ingestion protocol and the inconvenience of capsule ingestion in the supine position. The aim of this study was therefore to test a simplified ingestion procedure (SIP) for PillCam ESO. Using a cross-over study design, the SIP was prospectively compared with the original ingestion procedure for PillCam ESO in 24 healthy volunteers (15 men, nine women; mean age 44, range 27 - 70) and evaluated for: bubbles/saliva interference at the Z-line, Z-line circumferential visualization (quadrants), and convenience and ease of the ingestion procedure. All Rapid 4 videos were reviewed in a randomized manner and read by an experienced PillCam ESO reader blinded to the ingestion procedure used. It was found that the SIP significantly improved visualization in comparison with the original ingestion procedure, with less interference due to bubbles/saliva observed at the gastroesophageal junction ( P = 0.002) and improved visualization of the Z-line ( P = 0.025). Although the esophageal transit time was significantly faster with the SIP (3 : 45 min vs. 0 : 38 min; P = 0.0001), there were no differences in the number of Z-line frames/images captured. This new, simplified ingestion procedure for PillCam ESO provides significantly improved visualization of the Z-line in healthy volunteers. The overall test characteristics of PillCam ESO using SIP should be tested in patients with esophageal disease.

Laser transit anemometer measurements on a slender cone in the Langley unitary plan wind tunnel

NASA Technical Reports Server (NTRS)

Humphreys, William M., Jr.; Hunter, William W., Jr.; Covell, Peter F.; Nichols, Cecil E., Jr.

1990-01-01

A laser transit anemometer (LTA) system was used to probe the boundary layer on a slender (5 degree half angle) cone model in the Langley unitary plan wind tunnel. The anemometer system utilized a pair of laser beams with a diameter of 40 micrometers spaced 1230 micrometers apart to measure the transit times of ensembles of seeding particles using a cross-correlation technique. From these measurements, boundary layer profiles around the model were constructed and compared with CFD calculations. The measured boundary layer profiles representing the boundary layer velocity normalized to the edge velocity as a function of height above the model surface were collected with the model at zero angle of attack for four different flow conditions, and were collected in a vertical plane that bisected the model's longitudinal center line at a location 635 mm from the tip of the forebody cone. The results indicate an excellent ability of the LTA system to make velocity measurements deep into the boundary layer. However, because of disturbances in the flow field caused by onboard seeding, premature transition occurred implying that upstream seeding is mandatory if model flow field integrity is to be maintained. A description and results of the flow field surveys are presented.

The complex duration perception of emotional faces: effects of face direction.

PubMed

Kliegl, Katrin M; Limbrecht-Ecklundt, Kerstin; Dürr, Lea; Traue, Harald C; Huckauf, Anke

2015-01-01

The perceived duration of emotional face stimuli strongly depends on the expressed emotion. But, emotional faces also differ regarding a number of other features like gaze, face direction, or sex. Usually, these features have been controlled by only using pictures of female models with straight gaze and face direction. Doi and Shinohara (2009) reported that an overestimation of angry faces could only be found when the model's gaze was oriented toward the observer. We aimed at replicating this effect for face direction. Moreover, we explored the effect of face direction on the duration perception sad faces. Controlling for the sex of the face model and the participant, female and male participants rated the duration of neutral, angry, and sad face stimuli of both sexes photographed from different perspectives in a bisection task. In line with current findings, we report a significant overestimation of angry compared to neutral face stimuli that was modulated by face direction. Moreover, the perceived duration of sad face stimuli did not differ from that of neutral faces and was not influenced by face direction. Furthermore, we found that faces of the opposite sex appeared to last longer than those of the same sex. This outcome is discussed with regards to stimulus parameters like the induced arousal, social relevance, and an evolutionary context.

Survey of cognitive rehabilitation practices in the state of Kuwait.

PubMed

Manee, Fahad S; Nadar, Mohammed Sh; Jassem, Zainab; Chavan, Shashidhar Rao

2017-03-01

Background Rehabilitation professionals must be astute at recognizing, assessing, and treating individuals with cognitive deficits. No research is available to examine cognitive rehabilitation practices applied to individuals with neurological conditions in Kuwait. To identify the use of cognitive assessments, the availability of resources, and the barriers to cognitive rehabilitation practices in Kuwait. Methods Face-to-face interviews were conducted with health care professionals working with adult individuals with neurological conditions. These professionals included occupational therapists, speech-language pathologists, psychiatrists, and neurologists. Results The most commonly used cognitive based assessments are MMSE (41%), and MoCA and LOTCA (15.2%). The only clinical assessment used is the Line-Bisection Test (2.2%). The most used occupation-based assessments are FIM (6.5%), COPM (4.3%), the Interest Checklist (2.2%), and the Barthel Index (2.2%). Resources related to cognitive rehabilitation in Kuwait that are unavailable to practitioners include journal clubs (91%), special interest groups (89%), and continuing education programmes (82.6%). Barriers to cognitive rehabilitation practice included lack of sufficient funds for continuing education, lack of time, lack of standardized assessments, and lack of inter-professional teamwork. Conclusion Many adults in Kuwait live with cognitive impairment. There is a need to develop appropriate evidence-based cognitive rehabilitation clinical guidelines in Kuwait.

Cognitive rehabilitation with right hemifield eye-patching for patients with sub-acute stroke and visuo-spatial neglect: a randomized controlled trial.

PubMed

Aparicio-López, Celeste; García-Molina, Alberto; García-Fernández, Juan; Lopez-Blazquez, Raquel; Enseñat-Cantallops, Antonia; Sánchez-Carrión, Rocío; Muriel, Vega; Tormos, Jose María; Roig-Rovira, Teresa

2015-01-01

To assess whether, following a right-hemisphere stroke, the combined administration of computer-based cognitive rehabilitation and right hemifield eye-patching in patients with visuo-spatial neglect is more effective than computer-based cognitive rehabilitation alone. Twelve patients were randomized into two treatment groups: a single treatment group (n = 7) and a combination treatment group (n = 5). In both cases, the treatment consisted of a mean number of 15 sessions, each lasting 1 hour. Visuo-spatial neglect was assessed using a specific exploration protocol (Bell Cancellation Test, Figure Copying of Odgen, Line Bisection, Baking Tray Task and Reading Task). The functional effects of the treatment were assessed using the Catherine Bergego Scale. Significant between-group differences were observed when comparing the pre- and post-treatment scores for the Reading Task. No differences were observed in either group in the Catherine Bergego Scale administered at baseline and at the final intervention. The results obtained do not allow one to conclude that the combination treatment with cognitive rehabilitation and right hemifield eye-patching is more effective than cognitive rehabilitation alone. Although partial improvement in the performance of neuropsychological tests was observed, this improvement is not present at functional level.

Endoscopic carpal tunnel release using the modified Chow's extrabursal dual portal technique: clinical results of 640 patients.

PubMed

Kim, Poong-Taek; Micić, Ivan D; Park, Il-Hyng; Jeon, In-ho

2007-01-01

During a 4-year period, a total of 784 wrists of 640 patients were treated using a modified Chow's extrabursal dual portal endoscopic technique. All surgeries were performed under local anesthesia. A 1-cm incision was marked 1-2 cm proximal to the distal wrist crease, in the midline, ulnar to the palmaris longus. A distal portal was established along a line bisecting an angle created by the intersection of the ulnar border of the abducted thumb and the third web space. An obturator and cannula assembly were inserted under the portal, and three blades were used to cut under endoscopic vision. Subjective results showed that 706 hands (90%) had a reduction in the severity of pain after carpal tunnel release, 706 hands (90%) had a reduction in the severity of paresthesia and 729 hands (93%) had a reduction in the severity of numbness. Nocturnal pain and paresthesia were relieved in 745 cases (95%). Compared with the conventional open carpal tunnel release, less postoperative pain and faster recovery have been reported following endoscopic carpal tunnel release. This study suggests that extrabursal dual portal technique is a safe and reliable treatment option for carpal tunnel syndrome with a high success rate.

Psychometric properties of the Stroke Impairment Assessment Set (SIAS).

PubMed

Liu, Meigen; Chino, Naoichi; Tuji, Testuya; Masakado, Yoshihisa; Hase, Kimitaka; Kimura, Akio

2002-12-01

To review the psychometric properties of the Stroke Impairment Assessment Set (SAS), which was developed in 1990 as a comprehensive instrument to assess stroke impairment. Articles related to the SIAS were retrieved from the MEDLINE and the Folia Centro Japonica. Thirty-five articles were retrieved and analyzed. 1) Scale quality: Rasch analysis demonstrated the unidimensionality of the SIAS. Factor analysis produced factors corresponding to the 6 SIAS subscales. 2) Interrater reliability: The weighted kappas were high except for the unaffected side quadriceps item for which the score distribution was skewed. 3) Concurrent validity: Significant correlations were found between a) SIAS motor items and the Motricity Index or the Brunnstrom stage, b) SIAS lower extremity scores and the Functional Independence Measure (FIMSM) locomotion scores, c) trunk scores and abdominal manual muscle testing, d) visuospatial scores and line bisection and copying task scores, and e) speech scores and the FIMSM communication scores. 4) Predictive validity: Three studies attempting to predict discharge functional status demonstrated that adding the SIAS as one of the predictors enhanced the predictive power 5) Responsiveness: The SIAS was more responsive to changes than the Motricity Index, the Brunnstrom stage, or the National Institutes of Health Stroke Scale. The SIAS is a useful measure of stroke impairment with well-established psychometric properties.

How does reading direction modulate perceptual asymmetry effects?

PubMed

Chung, Harry K S; Liu, Joyce Y W; Hsiao, Janet H

2017-08-01

Left-side bias effects refer to a bias towards the left side of the stimulus/space in perceptual/visuospatial judgments, and are argued to reflect dominance of right hemisphere processing. It remains unclear whether reading direction can also account for the bias effect. Previous studies comparing readers of languages read from left to right with those read from right to left (e.g., French vs. Hebrew) have obtained inconsistent results. As a language that can be read from left to right or from right to left, Chinese provides a unique opportunity for a within-culture examination of reading direction effects. Chinese participants performed a perceptual judgment task (with both face and Chinese character stimuli; Experiment 1) and two visuospatial attention tasks (the greyscales and line bisection tasks; Experiment 2) once before and once after a reading task, in which they read Chinese passages either from left to right or from right to left for about 20 min. After reading from right to left, participants showed significantly reduced left-side bias in Chinese character perceptual judgments but not in the other three tasks. This effect suggests that the role of reading direction on different forms of left-side bias may differ, and its modulation may be stimulus-specific.

Longitudinal Changes in Visual Acuity and Health Related Quality of Life. The Los Angeles Latino Eye Study

PubMed Central

McKean-Cowdin, Roberta; Varma, Rohit; Hays, Ron D.; Wu, Joanne; Choudhury, Farzana; Azen, Stanley P.

2010-01-01

Purpose To examine the association between longitudinal changes in visual acuity (VA) and Health Related Quality of Life (HRQOL) in a population-based sample of adult Latinos. Design A population-based cohort study of eye disease in Latinos. Participants 3,169 adult Latino participants who live in the city of La Puente, California. Methods Data for these analyses were collected for the Los Angeles Latino Eye Study (LALES). Distance visual acuity (VA) was measured during a detailed ophthalmologic examination using the standard Early Treatment Diabetic Retinopathy Study protocol at baseline and a 4 year follow-up examination. HRQOL was assessed by the National Eye Institute Visual Function Questionnaire (NEI-VFQ-25) and the Medical Outcomes Study 12-Item Short-Form Health Survey version 1 (SF-12 v.1). Main Outcome Measures Mean differences in HRQOL composite and subscale scores between baseline and follow-up were calculated for 3,169 participants with complete clinical examination and HRQOL data at both time points. Mean differences and effect sizes (ES) for NEI-VFQ and SF-12 v.1 scores were calculated for 3 categories of VA change over the 4 year follow-up period (VA improved ≥ 2 lines, no change in VA or −2

Study of Pattern of Change in Handwriting Class Characters with Different Grades of Myopia

PubMed Central

Hedge, Shruti Prabhat; Sriram

2015-01-01

Introduction Handwriting is a visuo-motor skill highly dependent on visual skills. Any defect in the visual inputs could affect a change in the handwriting. Understanding the variation in handwriting characters caused by visual acuity change can help in identifying learning disabilities in children and also assess the disability in elderly. In our study we try to analyse and catalogue these changes in the handwriting of a person. Materials and Methods The study was conducted among 100 subjects having normal visual acuity. They were asked to perform a set of writing tasks, after which the same tasks were repeated after inducing different grades of myopia. Changes in the handwriting class characters were analysed and compared in all grades of myopia. Results In the study it was found that the letter size, pastiosity, word omissions, inability to stay on line all increase with changes in visual acuity. However these finding are not proportional to the grade of myopia. Conclusion From the findings of the study it can be concluded that myopia significantly influences the handwriting and any change in visual acuity would induce corresponding changes in handwriting. There is increase in letter size, pastiosity where as the ability to stay on line and space between the lines decrease in different grades of myopia. The changes are not linear and cannot be used to predict the grade of myopia but can be used as parameters suggestive of refractive error. PMID:26816917

Evidence for arousal-biased competition in perceptual learning.

PubMed

Lee, Tae-Ho; Itti, Laurent; Mather, Mara

2012-01-01

Arousal-biased competition theory predicts that arousal biases competition in favor of perceptually salient stimuli and against non-salient stimuli (Mather and Sutherland, 2011). The current study tested this hypothesis by having observers complete many trials in a visual search task in which the target either always was salient (a 55° tilted line among 80° distractors) or non-salient (a 55° tilted line among 50° distractors). Each participant completed one session in an emotional condition, in which visual search trials were preceded by negative arousing images, and one session in a non-emotional condition, in which the arousing images were replaced with neutral images (with session order counterbalanced). Test trials in which the target line had to be selected from among a set of lines with different tilts revealed that the emotional condition enhanced identification of the salient target line tilt but impaired identification of the non-salient target line tilt. Thus, arousal enhanced perceptual learning of salient stimuli but impaired perceptual learning of non-salient stimuli.

Evidence for Arousal-Biased Competition in Perceptual Learning

PubMed Central

Lee, Tae-Ho; Itti, Laurent; Mather, Mara

2012-01-01

Arousal-biased competition theory predicts that arousal biases competition in favor of perceptually salient stimuli and against non-salient stimuli (Mather and Sutherland, 2011). The current study tested this hypothesis by having observers complete many trials in a visual search task in which the target either always was salient (a 55° tilted line among 80° distractors) or non-salient (a 55° tilted line among 50° distractors). Each participant completed one session in an emotional condition, in which visual search trials were preceded by negative arousing images, and one session in a non-emotional condition, in which the arousing images were replaced with neutral images (with session order counterbalanced). Test trials in which the target line had to be selected from among a set of lines with different tilts revealed that the emotional condition enhanced identification of the salient target line tilt but impaired identification of the non-salient target line tilt. Thus, arousal enhanced perceptual learning of salient stimuli but impaired perceptual learning of non-salient stimuli. PMID:22833729

Genetically fluorescent melanoma bone and organ metastasis models.

PubMed

Yang, M; Jiang, P; An, Z; Baranov, E; Li, L; Hasegawa, S; Al-Tuwaijri, M; Chishima, T; Shimada, H; Moossa, A R; Hoffman, R M

1999-11-01

We report here the establishment and metastatic properties of bright, highly stable, green fluorescent protein (GFP) expression transductants of the B16 mouse malignant melanoma cell line and the LOX human melanoma line. The highly fluorescent malignant melanoma cell lines allowed the visualization of skeletal and multiorgan metastases after i.v. injection of B16 cells in C57BL/6 mice and intradermal injection of LOX cells in nude mice. The melanoma cell lines were transduced with the pLEIN expression retroviral vector containing the GFP and neomycin resistance genes. Stable B16F0 and LOX clones expressing high levels of GFP were selected stepwise in vitro in levels of G418 of up to 800 microg/ml. Extensive bone and bone marrow metastases of B16F0 were visualized by GFP expression when the animals were sacrificed 3 weeks after cell implantation. Metastases for both cell lines were visualized in many organs, including the brain, lung, pleural membrane, liver, kidney, adrenal gland, lymph nodes, skeleton, muscle, and skin by GFP fluorescence. This is the first observation of experimental skeletal metastases of melanoma, which was made possible by GFP expression. These models should facilitate future studies of the mechanism and therapy of bone and multiorgan metastasis of melanoma.

FAST (Four chamber view And Swing Technique) Echo: a Novel and Simple Algorithm to Visualize Standard Fetal Echocardiographic Planes

PubMed Central

Yeo, Lami; Romero, Roberto; Jodicke, Cristiano; Oggè, Giovanna; Lee, Wesley; Kusanovic, Juan Pedro; Vaisbuch, Edi; Hassan, Sonia S.

2010-01-01

Objective To describe a novel and simple algorithm (FAST Echo: Four chamber view And Swing Technique) to visualize standard diagnostic planes of fetal echocardiography from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView). Methods We developed an algorithm to image standard fetal echocardiographic planes by drawing four dissecting lines through the longitudinal view of the ductal arch contained in a STIC volume dataset. Three of the lines are locked to provide simultaneous visualization of targeted planes, and the fourth line (unlocked) “swings” through the ductal arch image (“swing technique”), providing an infinite number of cardiac planes in sequence. Each line generated the following plane(s): 1) Line 1: three-vessels and trachea view; 2) Line 2: five-chamber view and long axis view of the aorta (obtained by rotation of the five-chamber view on the y-axis); 3) Line 3: four-chamber view; and 4) “Swing” line: three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach. The algorithm was then tested in 50 normal hearts (15.3 – 40 weeks of gestation) and visualization rates for cardiac diagnostic planes were calculated. To determine if the algorithm could identify planes that departed from the normal images, we tested the algorithm in 5 cases with proven congenital heart defects. Results In normal cases, the FAST Echo algorithm (3 locked lines and rotation of the five-chamber view on the y-axis) was able to generate the intended planes (longitudinal view of the ductal arch, pulmonary artery, three-vessels and trachea view, five-chamber view, long axis view of the aorta, four-chamber view): 1) individually in 100% of cases [except for the three-vessel and trachea view, which was seen in 98% (49/50)]; and 2) simultaneously in 98% (49/50). The “swing technique” was able to generate the three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach in 100% of normal cases. In the abnormal cases, the FAST Echo algorithm demonstrated the cardiac defects and displayed views that deviated from what was expected from the examination of normal hearts. The “swing technique” was useful in demonstrating the specific diagnosis due to visualization of an infinite number of cardiac planes in sequence. Conclusions This novel and simple algorithm can be used to visualize standard fetal echocardiographic planes in normal fetal hearts. The FAST Echo algorithm may simplify examination of the fetal heart and could reduce operator dependency. Using this algorithm, the inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease. PMID:20878671

Four-chamber view and 'swing technique' (FAST) echo: a novel and simple algorithm to visualize standard fetal echocardiographic planes.

PubMed

Yeo, L; Romero, R; Jodicke, C; Oggè, G; Lee, W; Kusanovic, J P; Vaisbuch, E; Hassan, S

2011-04-01

To describe a novel and simple algorithm (four-chamber view and 'swing technique' (FAST) echo) for visualization of standard diagnostic planes of fetal echocardiography from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView). We developed an algorithm to image standard fetal echocardiographic planes by drawing four dissecting lines through the longitudinal view of the ductal arch contained in a STIC volume dataset. Three of the lines are locked to provide simultaneous visualization of targeted planes, and the fourth line (unlocked) 'swings' through the ductal arch image (swing technique), providing an infinite number of cardiac planes in sequence. Each line generates the following plane(s): (a) Line 1: three-vessels and trachea view; (b) Line 2: five-chamber view and long-axis view of the aorta (obtained by rotation of the five-chamber view on the y-axis); (c) Line 3: four-chamber view; and (d) 'swing line': three-vessels and trachea view, five-chamber view and/or long-axis view of the aorta, four-chamber view and stomach. The algorithm was then tested in 50 normal hearts in fetuses at 15.3-40 weeks' gestation and visualization rates for cardiac diagnostic planes were calculated. To determine whether the algorithm could identify planes that departed from the normal images, we tested the algorithm in five cases with proven congenital heart defects. In normal cases, the FAST echo algorithm (three locked lines and rotation of the five-chamber view on the y-axis) was able to generate the intended planes (longitudinal view of the ductal arch, pulmonary artery, three-vessels and trachea view, five-chamber view, long-axis view of the aorta, four-chamber view) individually in 100% of cases (except for the three-vessels and trachea view, which was seen in 98% (49/50)) and simultaneously in 98% (49/50). The swing technique was able to generate the three-vessels and trachea view, five-chamber view and/or long-axis view of the aorta, four-chamber view and stomach in 100% of normal cases. In the abnormal cases, the FAST echo algorithm demonstrated the cardiac defects and displayed views that deviated from what was expected from the examination of normal hearts. The swing technique was useful for demonstrating the specific diagnosis due to visualization of an infinite number of cardiac planes in sequence. This novel and simple algorithm can be used to visualize standard fetal echocardiographic planes in normal fetal hearts. The FAST echo algorithm may simplify examination of the fetal heart and could reduce operator dependency. Using this algorithm, inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease. Copyright © 2011 ISUOG. Published by John Wiley & Sons, Ltd.

Drawing the Line between Constituent Structure and Coherence Relations in Visual Narratives

ERIC Educational Resources Information Center

Cohn, Neil; Bender, Patrick

2017-01-01

Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of visual narrative grammar posits that hierarchic "grammatical" structures operate at the…

The Effects of Pictorial Complexity and Cognitive Style on Visual Recall Memory.

ERIC Educational Resources Information Center

Jesky, Romaine R.; Berry, Louis H.

The effect of the interaction between cognitive style differences (field dependence/field independence) and various degrees of visual complexity on pictorial recall memory was explored using three sets of visuals in three different formats--line drawing, black and white, and color. The subjects were 86 undergraduate students enrolled in two core…

Visual and Verbal Literacy.

ERIC Educational Resources Information Center

Stewig, John Warren

Visual literacy--seeing with insight--enables child viewers of pictures to examine elements such as color, line, shape, form, depth, and detail to see what relations exist both among these components and between what is in the picture and their previous visual experience. The viewer can extract meaning and respond to it, either by talking or…

The Visual Side to Numeracy: Students' Sensemaking with Graphics

ERIC Educational Resources Information Center

Diezmann, Carmel; Lowrie, Tom; Sugars, Lindy; Logan, Tracy

2009-01-01

The 21st century has placed increasing demand on individuals' proficiency with a wide array of visual representations, that is graphics. Hence, proficiency with visual tasks needs to be embedded across the curriculum. In mathematics, various graphics (e.g., maps, charts, number lines, graphs) are used as means of communication of mathematical…

Memory-guided saccade processing in visual form agnosia (patient DF).

PubMed

Rossit, Stéphanie; Szymanek, Larissa; Butler, Stephen H; Harvey, Monika

2010-01-01

According to Milner and Goodale's model (The visual brain in action, Oxford University Press, Oxford, 2006) areas in the ventral visual stream mediate visual perception and oV-line actions, whilst regions in the dorsal visual stream mediate the on-line visual control of action. Strong evidence for this model comes from a patient (DF), who suffers from visual form agnosia after bilateral damage to the ventro-lateral occipital region, sparing V1. It has been reported that she is normal in immediate reaching and grasping, yet severely impaired when asked to perform delayed actions. Here we investigated whether this dissociation would extend to saccade execution. Neurophysiological studies and TMS work in humans have shown that the posterior parietal cortex (PPC), on the right in particular (supposedly spared in DF), is involved in the control of memory-guided saccades. Surprisingly though, we found that, just as reported for reaching and grasping, DF's saccadic accuracy was much reduced in the memory compared to the stimulus-guided condition. These data support the idea of a tight coupling of eye and hand movements and further suggest that dorsal stream structures may not be sufficient to drive memory-guided saccadic performance.

In-flight flow visualization with pressure measurements at low speeds on the NASA F-18 high alpha research vehicle

NASA Technical Reports Server (NTRS)

Delfrate, John H.; Fisher, David F.; Zuniga, Fanny A.

1990-01-01

In-flight results from surface and off-surface flow visualizations and from extensive pressure distributions document the vortical flow on the leading edge extensions (LEX) and forebody of the NASA F-18 high alpha research vehicle for low speeds and angles of attack up to 50 degs. Surface flow visualization data, obtained using the emitted fluid technique, were used to define separation lines and laminar separation bubbles. Off-surface flow visualization data, obtained by smoke injection, were used to document both the path of the vortex cores and the location of vortex core breakdown. The location of vortex core breakdown correlated well with the loss of suction pressure on the LEX and with the flow visualization results from ground facilities. Surface flow separation lines on the LEX and forebody corresponded well with the end of pressure recovery under the vortical flows. Correlation of the pressures with wind tunnel results show fair to good correlation.

The Topography Tub Learning Activity

NASA Astrophysics Data System (ADS)

Glesener, G. B.

2014-12-01

Understanding the basic elements of a topographic map (i.e. contour lines and intervals) is just a small part of learning how to use this abstract representational system as a resource in geologic mapping. Interpretation of a topographic map and matching its features with real-world structures requires that the system is utilized for visualizing the shapes of these structures and their spatial orientation. To enrich students' skills in visualizing topography from topographic maps a spatial training activity has been developed that uses 3D objects of various shapes and sizes, a sighting tool, a plastic basin, water, and transparencies. In the first part of the activity, the student is asked to draw a topographic map of one of the 3D objects. Next, the student places the object into a plastic tub in which water is added to specified intervals of height. The shoreline at each interval is used to reference the location of the contour line the student draws on a plastic inkjet transparency directly above the object. A key part of this activity is the use of a sighting tool by the student to assist in keeping the pencil mark directly above the shoreline. It (1) ensures the accurate positioning of the contour line and (2) gives the learner experience with using a sight before going out into the field. Finally, after the student finishes drawing the contour lines onto the transparency, the student can compare and contrast the two maps in order to discover where improvements in their visualization of the contours can be made. The teacher and/or peers can also make suggestions on ways to improve. A number of objects with various shapes and sizes are used in this exercise to produce contour lines representing the different types of topography the student may encounter while field mapping. The intended outcome from using this visualization training activity is improvement in performance of visualizing topography as the student moves between the topographic representation and corresponding topography in the field.

Perceptual learning in children with visual impairment improves near visual acuity.

PubMed

Huurneman, Bianca; Boonstra, F Nienke; Cox, Ralf F A; van Rens, Ger; Cillessen, Antonius H N

2013-09-17

This study investigated whether visual perceptual learning can improve near visual acuity and reduce foveal crowding effects in four- to nine-year-old children with visual impairment. Participants were 45 children with visual impairment and 29 children with normal vision. Children with visual impairment were divided into three groups: a magnifier group (n = 12), a crowded perceptual learning group (n = 18), and an uncrowded perceptual learning group (n = 15). Children with normal vision also were divided in three groups, but were measured only at baseline. Dependent variables were single near visual acuity (NVA), crowded NVA, LH line 50% crowding NVA, number of trials, accuracy, performance time, amount of small errors, and amount of large errors. Children with visual impairment trained during six weeks, two times per week, for 30 minutes (12 training sessions). After training, children showed significant improvement of NVA in addition to specific improvements on the training task. The crowded perceptual learning group showed the largest acuity improvements (1.7 logMAR lines on the crowded chart, P < 0.001). Only the children in the crowded perceptual learning group showed improvements on all NVA charts. Children with visual impairment benefit from perceptual training. While task-specific improvements were observed in all training groups, transfer to crowded NVA was largest in the crowded perceptual learning group. To our knowledge, this is the first study to provide evidence for the improvement of NVA by perceptual learning in children with visual impairment. (http://www.trialregister.nl number, NTR2537.).

Visual Navigation in Nocturnal Insects.

PubMed

Warrant, Eric; Dacke, Marie

2016-05-01

Despite their tiny eyes and brains, nocturnal insects have evolved a remarkable capacity to visually navigate at night. Whereas some use moonlight or the stars as celestial compass cues to maintain a straight-line course, others use visual landmarks to navigate to and from their nest. These impressive abilities rely on highly sensitive compound eyes and specialized visual processing strategies in the brain. ©2016 Int. Union Physiol. Sci./Am. Physiol. Soc.

Using perceptual rules in interactive visualization

NASA Astrophysics Data System (ADS)

Rogowitz, Bernice E.; Treinish, Lloyd A.

1994-05-01

In visualization, data are represented as variations in grayscale, hue, shape, and texture. They can be mapped to lines, surfaces, and glyphs, and can be represented statically or in animation. In modem visualization systems, the choices for representing data seem unlimited. This is both a blessing and a curse, however, since the visual impression created by the visualization depends critically on which dimensions are selected for representing the data (Bertin, 1967; Tufte, 1983; Cleveland, 1991). In modem visualization systems, the user can interactively select many different mapping and representation operations, and can interactively select processing operations (e.g., applying a color map), realization operations (e.g., generating geometric structures such as contours or streamlines), and rendering operations (e.g., shading or ray-tracing). The user can, for example, map data to a color map, then apply contour lines, then shift the viewing angle, then change the color map again, etc. In many systems, the user can vary the choices for each operation, selecting, for example, particular color maps, contour characteristics, and shading techniques. The hope is that this process will eventually converge on a visual representation which expresses the structure of the data and effectively communicates its message in a way that meets the user's goals. Sometimes, however, it results in visual representations which are confusing, misleading, and garish.

When apperceptive agnosia is explained by a deficit of primary visual processing.

PubMed

Serino, Andrea; Cecere, Roberto; Dundon, Neil; Bertini, Caterina; Sanchez-Castaneda, Cristina; Làdavas, Elisabetta

2014-03-01

Visual agnosia is a deficit in shape perception, affecting figure, object, face and letter recognition. Agnosia is usually attributed to lesions to high-order modules of the visual system, which combine visual cues to represent the shape of objects. However, most of previously reported agnosia cases presented visual field (VF) defects and poor primary visual processing. The present case-study aims to verify whether form agnosia could be explained by a deficit in basic visual functions, rather that by a deficit in high-order shape recognition. Patient SDV suffered a bilateral lesion of the occipital cortex due to anoxia. When tested, he could navigate, interact with others, and was autonomous in daily life activities. However, he could not recognize objects from drawings and figures, read or recognize familiar faces. He was able to recognize objects by touch and people from their voice. Assessments of visual functions showed blindness at the centre of the VF, up to almost 5°, bilaterally, with better stimulus detection in the periphery. Colour and motion perception was preserved. Psychophysical experiments showed that SDV's visual recognition deficits were not explained by poor spatial acuity or by the crowding effect. Rather a severe deficit in line orientation processing might be a key mechanism explaining SDV's agnosia. Line orientation processing is a basic function of primary visual cortex neurons, necessary for detecting "edges" of visual stimuli to build up a "primal sketch" for object recognition. We propose, therefore, that some forms of visual agnosia may be explained by deficits in basic visual functions due to widespread lesions of the primary visual areas, affecting primary levels of visual processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

Unilateral spatial neglect in the acute phase of ischemic stroke can predict long-term disability and functional capacity.

PubMed

Luvizutto, Gustavo José; Moliga, Augusta Fabiana; Rizzatti, Gabriela Rizzo Soares; Fogaroli, Marcelo Ortolani; Moura Neto, Eduardo de; Nunes, Hélio Rubens de Carvalho; Resende, Luiz Antônio de Lima; Bazan, Rodrigo

2018-05-21

The aim of this study was to assess the relationship between the degree of unilateral spatial neglect during the acute phase of stroke and long-term functional independence. This was a prospective study of right ischemic stroke patients in which the independent variable was the degree of spatial neglect and the outcome that was measured was functional independence. The potential confounding factors included sex, age, stroke severity, topography of the lesion, risk factors, glycemia and the treatment received. Unilateral spatial neglect was measured using the line cancellation test, the star cancellation test and the line bisection test within 48 hours of the onset of symptoms. Functional independence was measured using the modified Rankin and Barthel scales at 90 days after discharge. The relationship between unilateral spatial neglect and functional independence was analyzed using multiple logistic regression that was corrected for confounding factors. We studied 60 patients with a median age of 68 (34-89) years, 52% of whom were male and 74% of whom were Caucasian. The risk for moderate to severe disability increased with increasing star cancellation test scores (OR=1.14 [1.03-1.26], p=0.01) corrected for the stroke severity, which was a confounding factor that had a statistically positive association with disability (OR=1.63 [1.13-2.65], p=0.01). The best chance of functional independence decreased with increasing star cancellation test scores (OR=0.86 [0.78-0.96], p=0.006) corrected for the stroke severity, which was a confounding factor that had a statistically negative association with independence (OR=0.66 [0.48-0.92], p=0.017). The severity of unilateral spatial neglect in acute stroke worsens the degree of long-term disability and functional independence.

Magnetic field structure in Monoceros R2

NASA Technical Reports Server (NTRS)

Jarrett, T. H.; Novak, G.; Xie, T.; Goldsmith, P. F.

1994-01-01

We have carried out polarimetric observations to investigate the geometry of the magnetic field in the giant molecular cloud Monoceros R2. This study is based upon deep R-band charge coupled device (CCD) polarimetry, covering a total area of 0.5 deg(exp 2) of the giant molecular cloud. The data were calibrated using a new technique that relies on obtaining broad-band photometry of stars simultaneously with polarimetric photometry of the Mon R2 fields, thus providing an accurate means of measuring the electric vectors of starlight which is polarized by the fore-ground dust grains aligned by the magnetic field in the Mon R2 GMC. In this work, (1) we were able to continuously trace magnetic field lines from the largest scales in Mon R2 to the detailed structure of the field in the dense core, as determined from infrared polarimetry; and (2) we have found that the ambient field is apparently modified by a large-scale structure in the Mon R2 cloud. The mean angle of polarization for the complete sample we measured is 158 deg, which is roughly coincident with the local Galactic magnetic field (155 deg). The dispersion in the angle of polarization is 33 deg, similar to that found in the Orion GMC. The dispersion in angle of polarization for stars located along the western side of the three CCD fields is 22 deg. The CCD fields are bisected by a dense ridge of gas defining the boundary of an expanding gas shell that recent observational results at millimeter wavelengths now reveal dominates the Mon R2 GMC. Our results suggest th at the expanding shell has distorted the magnetic field lines extending from the core to the northern gas structure comprising Mon R2.

Visualization of Flow in Pressurizer Spray Line Piping and Estimation of Thermal Stress Fluctuation Caused by Swaying of Water Surface

NASA Astrophysics Data System (ADS)

Oumaya, Toru; Nakamura, Akira; Onojima, Daisuke; Takenaka, Nobuyuki

The pressurizer spray line of PWR plants cools reactor coolant by injecting water into pressurizer. Since the continuous spray flow rate during commercial operation of the plant is considered insufficient to fill the pipe completely, there is a concern that a water surface exists in the pipe and may periodically sway. In order to identify the flow regimes in spray line piping and assess their impact on pipe structure, a flow visualization experiment was conducted. In the experiment, air was used substituted for steam to simulate the gas phase of the pressurizer, and the flow instability causing swaying without condensation was investigated. With a full-scale mock-up made of acrylic, flow under room temperature and atmospheric pressure conditions was visualized, and possible flow regimes were identified based on the results of the experiment. Three representative patterns of swaying of water surface were assumed, and the range of thermal stress fluctuation, when the surface swayed instantaneously, was calculated. With the three patterns of swaying assumed based on the visualization experiment, it was confirmed that the thermal stress amplitude would not exceed the fatigue endurance limit prescribed in the Japanese Design and Construction Code.

Demonstration and Validation of a Fractured Rock Passive Flux Meter

DTIC Science & Technology

2015-04-01

Thick continuous lines are stream lines and thin dashed lines are potential lines. Green lines are isochrones, i.e., dye , tracer or contaminant...layer of cloth material impregnated with a visible dye . The core inflates separately from the two end packers to provide a mechanism for holding the one...leaches visible dyes and tracers from the internal and external sorbent layers and produces residual dye and tracer distributions. Visual

Femtosecond-LASIK outcomes using the VisuMax®-MEL® 80 platform for mixed astigmatism refractive surgery.

PubMed

Stanca, Horia Tudor; Munteanu, Mihnea; Jianu, Dragoş Cătălin; Motoc, Andrei Gheorghe Marius; Jecan, Cristian Radu; Tăbăcaru, Bogdana; Stanca, Simona; Preda, Maria Alexandra

2018-01-01

To evaluate the predictability, efficacy and safety of Femtosecond-laser-assisted in situ keratomileusis (LASIK) procedure for mixed astigmatism. We prospectively evaluated for 12 months 74 eyes (52 patients) with mixed astigmatism that underwent Femtosecond-LASIK treatment. The preoperative mean refractive sphere value was +1.879±1.313 diopters (D) and the mean refractive cylinder value was -4.169±1.091 D. The anterior corneal flap was cut using the VisuMax® femtosecond laser and then the stromal ablation was done using the MEL® 80 excimer laser. Mean age was 30.22±6.421 years with 61.53% female patients. Postoperative spherical equivalent at 12 months was within ±0.5D of emmetropia in 75.8% of eyes and within ±1D in 97.3% of eyes. Postoperative uncorrected distance visual acuity was equivalent to or better than the preoperative corrected distance visual acuity in 91.9% of eyes. Compared to the preoperative corrected distance visual acuity (CDVA), 8.1% of eyes gained one line, 2.7% gained two lines and 2.7% gained three lines of visual acuity. Femtosecond-LASIK using the VisuMax®-MEL® 80 platform appears to have safe, effective and predictable results in mixed astigmatic eyes. The results are impressive for high refractive error treatment and for improvement of both uncorrected and corrected distance visual acuity.

Marine Corps Drill and Ceremonies Manual.

DTIC Science & Technology

1980-08-28

23 3-26 ii I I . . CHAPTER 4. MANUAL OF ARMS WITH HANDGUNS Para Page Pistol manual of arms ..................................... 4-1 4-1 Revolver...movement from orcier arms. (1) On the command of execution, AR3MS, grasp the barrel of the weapon with the right hand. Without loss of motion, raise and...forearm are straight. The right elbow is neld down without strain. The barrel is up and bisecting the angle formed by the neck and left shoulder. At the

Comparison of Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model in a successive temporal bisection task.

PubMed

Arantes, Joana

2008-06-01

The present research tested the generality of the "context effect" previously reported in experiments using temporal double bisection tasks [e.g., Arantes, J., Machado, A. Context effects in a temporal discrimination task: Further tests of the Scalar Expectancy Theory and Learning-to-Time models. J. Exp. Anal. Behav., in press]. Pigeons learned two temporal discriminations in which all the stimuli appear successively: 1s (red) vs. 4s (green) and 4s (blue) vs. 16s (yellow). Then, two tests were conducted to compare predictions of two timing models, Scalar Expectancy Theory (SET) and the Learning-to-Time (LeT) model. In one test, two psychometric functions were obtained by presenting pigeons with intermediate signal durations (1-4s and 4-16s). Results were mixed. In the critical test, pigeons were exposed to signals ranging from 1 to 16s and followed by the green or the blue key. Whereas SET predicted that the relative response rate to each of these keys should be independent of the signal duration, LeT predicted that the relative response rate to the green key (compared with the blue key) should increase with the signal duration. Results were consistent with LeT's predictions, showing that the context effect is obtained even when subjects do not need to make a choice between two keys presented simultaneously.

Emotion and Time Perception: Effects of Film-Induced Mood

PubMed Central

Droit-Volet, Sylvie; Fayolle, Sophie L.; Gil, Sandrine

2011-01-01

Previous research into emotion and time perception has been designed to study the time perception of emotional events themselves (e.g., facial expression). Our aim was to investigate the effect of emotions per se on the subsequent time judgment of a neutral, non-affective event. In the present study, the participants were presented with films inducing a specific mood and were subsequently given a temporal bisection task. More precisely, the participants were given two temporal bisection tasks, one before and the other after viewing the emotional film. Three emotional films were tested: one eliciting fear, another sadness, and a neutral control film. In addition, the direct mood experience was assessed using the Brief Mood Introspective Scale that was administered to the participants at the beginning and the end of the session. The results showed that the perception of time did not change after viewing either the neutral control films or the sad films although the participants reported being sadder and less aroused after than before watching the sad film clips. In contrast, the stimulus durations were judged longer after than before viewing the frightening films that were judged to increase the emotion of fear and arousal level. In combination with findings from previous studies, our data suggest that the selective lengthening effect after watching frightening films was mediated by an effect of arousal on the speed of the internal clock system. PMID:21886610

Vasopressin-induced constriction of the isolated rat occipital artery is segment dependent.

PubMed

Chelko, Stephen P; Schmiedt, Chad W; Lewis, Tristan H; Lewis, Stephen J; Robertson, Tom P

2013-01-01

Circulating factors delivered to the nodose ganglion (NG) by the occipital artery (OA) have been shown to affect vagal afferent activity, and thus the contractile state of the OA may influence blood flow to the NG. OA were isolated and bisected into proximal and distal segments relative to the external carotid artery. Bisection highlighted stark differences between maximal contractile responses and OA sensitivity. Specifically, maximum responses to vasopressin and the V1 receptor agonist were significantly higher in distal than proximal segments. Distal segments were significantly more sensitive to 5-hydroxytryptamine (5-HT) and the 5-HT2 receptor agonist than proximal segments. Angiotensin II (AT)2, V2 and 5-HT(1B/1D) receptor agonists did not elicit vascular responses. Additionally, AT1 receptor agonists elicited mild, yet not significantly different maximal responses between segments. The results of this study are consistent with contractile properties of rat OA being mediated via AT1, V1 and 5-HT2 receptors and dependent upon the OA segment. Furthermore, vasopressin-induced constriction of the OA, regardless of a bolus dose or a first and second concentration-response curve, retained this unique segmental difference. We hypothesize that these segmental differences may be important in the regulation of blood flow through the OA in health and disease. © 2013 S. Karger AG, Basel.

Interaction between Visual- and Goal-Related Neuronal Signals on the Trajectories of Saccadic Eye Movements

ERIC Educational Resources Information Center

White, Brian J.; Theeuwes, Jan; Munoz, Douglas P.

2012-01-01

During natural viewing, the trajectories of saccadic eye movements often deviate dramatically from a straight-line path between objects. In human studies, saccades have been shown to deviate toward or away from salient visual distractors depending on visual- and goal-related parameters, but the neurophysiological basis for this is not well…

Network Visualization Project (NVP)

DTIC Science & Technology

2016-07-01

network visualization, network traffic analysis, network forensics 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF...shell, is a command-line framework used for network forensic analysis. Dshell processes existing pcap files and filters output information based on

Saccade frequency response to visual cues during gait in Parkinson's disease: the selective role of attention.

PubMed

Stuart, Samuel; Lord, Sue; Galna, Brook; Rochester, Lynn

2018-04-01

Gait impairment is a core feature of Parkinson's disease (PD) with implications for falls risk. Visual cues improve gait in PD, but the underlying mechanisms are unclear. Evidence suggests that attention and vision play an important role; however, the relative contribution from each is unclear. Measurement of visual exploration (specifically saccade frequency) during gait allows for real-time measurement of attention and vision. Understanding how visual cues influence visual exploration may allow inferences of the underlying mechanisms to response which could help to develop effective therapeutics. This study aimed to examine saccade frequency during gait in response to a visual cue in PD and older adults and investigate the roles of attention and vision in visual cue response in PD. A mobile eye-tracker measured saccade frequency during gait in 55 people with PD and 32 age-matched controls. Participants walked in a straight line with and without a visual cue (50 cm transverse lines) presented under single task and dual-task (concurrent digit span recall). Saccade frequency was reduced when walking in PD compared to controls; however, visual cues ameliorated saccadic deficit. Visual cues significantly increased saccade frequency in both PD and controls under both single task and dual-task. Attention rather than visual function was central to saccade frequency and gait response to visual cues in PD. In conclusion, this study highlights the impact of visual cues on visual exploration when walking and the important role of attention in PD. Understanding these complex features will help inform intervention development. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

fluff: exploratory analysis and visualization of high-throughput sequencing data

PubMed Central

Georgiou, Georgios

2016-01-01

Summary. In this article we describe fluff, a software package that allows for simple exploration, clustering and visualization of high-throughput sequencing data mapped to a reference genome. The package contains three command-line tools to generate publication-quality figures in an uncomplicated manner using sensible defaults. Genome-wide data can be aggregated, clustered and visualized in a heatmap, according to different clustering methods. This includes a predefined setting to identify dynamic clusters between different conditions or developmental stages. Alternatively, clustered data can be visualized in a bandplot. Finally, fluff includes a tool to generate genomic profiles. As command-line tools, the fluff programs can easily be integrated into standard analysis pipelines. The installation is straightforward and documentation is available at http://fluff.readthedocs.org. Availability. fluff is implemented in Python and runs on Linux. The source code is freely available for download at https://github.com/simonvh/fluff. PMID:27547532

Differences in apparent straightness of dot and line stimuli.

NASA Technical Reports Server (NTRS)

Parlee, M. B.

1972-01-01

An investigation has been made of anisotropic responses to contoured and noncontoured stimuli to obtain an insight into the way these stimuli are processed. For this purpose, eight subjects judged the alignment of minimally contoured (3 dot) and contoured (line) stimuli. Stimuli, presented to each eye separately, vertically subtended either 8 or 32 deg visual angle and were located 10 deg left, center, or 10 deg right in the visual field. Location-dependent deviations from physical straightness were larger for dot stimuli than for lines. The results were the same for the two eyes. In a second experiment, subjects judged the alignment of stimuli composed of different densities of dots. Apparent straightness for these stimuli was the same as for lines. The results are discussed in terms of alternative mechanisms for analysis of contoured and minimally contoured stimuli.

What are the underlying units of perceived animacy? Chasing detection is intrinsically object-based.

PubMed

van Buren, Benjamin; Gao, Tao; Scholl, Brian J

2017-10-01

One of the most foundational questions that can be asked about any visual process is the nature of the underlying 'units' over which it operates (e.g., features, objects, or spatial regions). Here we address this question-for the first time, to our knowledge-in the context of the perception of animacy. Even simple geometric shapes appear animate when they move in certain ways. Do such percepts arise whenever any visual feature moves appropriately, or do they require that the relevant features first be individuated as discrete objects? Observers viewed displays in which one disc (the "wolf") chased another (the "sheep") among several moving distractor discs. Critically, two pairs of discs were also connected by visible lines. In the Unconnected condition, both lines connected pairs of distractors; but in the Connected condition, one connected the wolf to a distractor, and the other connected the sheep to a different distractor. Observers in the Connected condition were much less likely to describe such displays using mental state terms. Furthermore, signal detection analyses were used to explore the objective ability to discriminate chasing displays from inanimate control displays in which the wolf moved toward the sheep's mirror-image. Chasing detection was severely impaired on Connected trials: observers could readily detect an object chasing another object, but not a line-end chasing another line-end, a line-end chasing an object, or an object chasing a line-end. We conclude that the underlying units of perceived animacy are discrete visual objects.

Wavefront holoscopy: application of digital in-line holography for the inspection of engraved marks in progressive addition lenses.

PubMed

Perucho, Beatriz; Micó, Vicente

2014-01-01

Progressive addition lenses (PALs) are engraved with permanent marks at standardized locations in order to guarantee correct centering and alignment throughout the manufacturing and mounting processes. Out of the production line, engraved marks provide useful information about the PAL as well as act as locator marks to re-ink again the removable marks. Even though those marks should be visible by simple visual inspection with the naked eye, engraving marks are often faint and weak, obscured by scratches, and partially occluded and difficult to recognize on tinted or antireflection-coated lenses. Here, we present an extremely simple optical device (named as wavefront holoscope) for visualization and characterization of permanent marks in PAL based on digital in-line holography. Essentially, a point source of coherent light illuminates the engraved mark placed just before a CCD camera that records a classical Gabor in-line hologram. The recorded hologram is then digitally processed to provide a set of high-contrast images of the engraved marks. Experimental results are presented showing the applicability of the proposed method as a new ophthalmic instrument for visualization and characterization of engraved marks in PALs.

The Safety and Predictability of Implanting Autologous Lenticule Obtained by SMILE for Hyperopia.

PubMed

Sun, Ling; Yao, Peijun; Li, Meiyan; Shen, Yang; Zhao, Jing; Zhou, Xingtao

2015-06-01

To evaluate the safety, effectiveness, stability, and predictability of implanting autologous lenticules obtained from small incision lenticule extraction for the treatment of hyperopia. Five patients (10 eyes) with one myopic eye and one hyperopic eye were enrolled. The myopic eye was treated with small incision lenticule extraction; a lenticule was extracted and subsequently implanted in the hyperopic eye. Follow-up was at 1 day, 1, 3, 6, and 9 months, and 1 year postoperatively. Patients received a complete ophthalmologic examination at each visit, including uncorrected distance visual acuity, corrected distance visual acuity, anterior segment optical coherence tomography, and corneal topography. There were no complications in any eye during follow-up. Compared with preoperative levels, at the last follow-up visit the eyes with lenticule implantation showed mean spherical equivalent reduced by 5.53 diopters (residual spherical equivalent was +1.13 to -2.63 diopters), mean uncorrected distance visual acuity increased approximately two lines (approximately 20/63 to 20/40 Snellen), and corrected distance visual acuity in 4 (80%) eyes gained one line, 2 (40%) eyes gained two lines, and 1 (20%) eye gained more than two lines. There was no significant difference (P > .05) in spherical equivalent compared with 1 day postoperatively and the last follow-up visit. Corneal topography showed that the lenticule was uniform and located well; anterior segment optical coherence tomography images showed that the lenticule was transparent and the demarcation line was visible. Implanting an autologous lenticule obtained by small incision lenticule extraction for hyperopia might be safe, effective, and stable, but its predictability should be improved in the future. Copyright 2015, SLACK Incorporated.

A randomized trial of adding a plano lens to atropine for amblyopia.

PubMed

Wallace, David K; Lazar, Elizabeth L; Repka, Michael X; Holmes, Jonathan M; Kraker, Raymond T; Hoover, Darren L; Weise, Katherine K; Waters, Amy L; Rice, Melissa L; Peters, Robert J

2015-02-01

Some children have residual amblyopia after treatment with atropine eyedrops for amblyopia due to strabismus and/or anisometropia. We conducted a randomized clinical trial to evaluate the effectiveness of augmenting the effect of atropine by changing the lens over the fellow eye to plano in children with residual amblyopia. A total of 73 children 3 to <8 years of age (mean, 5.8 years) with stable residual amblyopia (range, 20/32 to 20/160, mean 20/63(+1)) were enrolled after at least 12 weeks of atropine treatment of the fellow eye. Participants were randomly assigned to continuing weekend atropine alone or wearing a plano lens over the fellow eye (while continuing atropine). The primary outcome was assessed at 10 weeks, and participants were followed until improvement ceased. At the 10-week primary outcome visit, amblyopic-eye visual acuity had improved an average of 1.1 lines with the plano lens and 0.6 lines with atropine only (difference adjusted for baseline visual acuity = + 0.5 line; 95% CI, -0.1 to +1.2). At the primary outcome or later visit when the best-measured visual acuity was observed, the mean amblyopic-eye improvement from baseline was 1.9 lines with the plano lens and 0.8 lines with atropine only. When amblyopic-eye visual acuity stops improving with atropine treatment, there may be a small benefit to augmenting atropine therapy with a plano lens over the fellow eye. However, the effect was not statistically significant, and the large confidence interval raises the possibility of no benefit or a benefit larger than we observed. A larger study would be necessary to get a more precise estimate of the treatment effect. Copyright © 2015 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.

Photoreceptor change and visual outcome after idiopathic epiretinal membrane removal with or without additional internal limiting membrane peeling.

PubMed

Ahn, Seong Joon; Ahn, Jeeyun; Woo, Se Joon; Park, Kyu Hyung

2014-01-01

To compare the postoperative photoreceptor status and visual outcome after epiretinal membrane removal with or without additional internal limiting membrane (ILM) peeling. Medical records of 40 eyes from 37 patients undergoing epiretinal membrane removal with residual ILM peeling (additional ILM peeling group) and 69 eyes from 65 patients undergoing epiretinal membrane removal without additional ILM peeling (no additional peeling group) were reviewed. The length of defects in cone outer segment tips, inner segment/outer segment junction, and external limiting membrane line were measured using spectral domain optical coherence tomography images of the fovea before and at 1, 3, 6, and 12 months after the surgery. Cone outer segment tips and inner segment/outer segment junction line defects were most severe at postoperative 1 month and gradually restored at 12 months postoperatively. The cone outer segment tips line defect in the additional ILM peeling group was significantly greater than that in the no additional peeling group at postoperative 1 month (P = 0.006), and best-corrected visual acuity was significantly worse in the former group at the same month (P = 0.001). There was no significant difference in the defect size and best-corrected visual acuity at subsequent visits and recurrence rates between the two groups. Patients who received epiretinal membrane surgery without additional ILM peeling showed better visual and anatomical outcome than those with additional ILM peeling at postoperative 1 month. However, surgical outcomes were comparable between the two groups, thereafter. In terms of visual outcome and photoreceptor integrity, additional ILM peeling may not be an essential procedure.

Perceived distance depends on the orientation of both the body and the visual environment.

PubMed

Harris, Laurence R; Mander, Charles

2014-10-15

Models of depth perception typically omit the orientation and height of the observer despite the potential usefulness of the height above the ground plane and the need to know about head position to interpret retinal disparity information. To assess the contribution of orientation to perceived distance, we used the York University Tumbled and Tumbling Room facilities to modulate both perceived and actual body orientation. These facilities are realistically decorated rooms that can be systematically arranged to vary the relative orientation of visual, gravity, and body cues to upright. To assess perceived depth we exploited size/distance constancy. Observers judged the perceived length of a visual line (controlled by a QUEST adaptive procedure) projected on to the wall of the facilities, relative to the length of an unseen iron rod held in their hands. In the Tumbled Room (viewing distance 337 cm) the line was set about 10% longer when participants were supine compared to when they were upright. In the Tumbling Room (viewing distance 114 cm), the line was set about 11% longer when participants were either supine or made to feel that they were supine by the orientation of the room. Matching a longer visual line to the reference rod is compatible with the opposite wall being perceived as closer. The effect was modulated by whether viewing was monocular or binocular at a viewing distance of 114 cm but not at 337 cm suggesting that reliable binocular cues can override the effect. © 2014 ARVO.

Quantitative visualization of synchronized insulin secretion from 3D-cultured cells

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

Suzuki, Takahiro; Kanamori, Takao; Inouye, Satoshi

Quantitative visualization of synchronized insulin secretion was performed in an isolated rat pancreatic islet and a spheroid of rat pancreatic beta cell line using a method of video-rate bioluminescence imaging. Video-rate images of insulin secretion from 3D-cultured cells were obtained by expressing the fusion protein of insulin and Gaussia luciferase (Insulin-GLase). A subclonal rat INS-1E cell line stably expressing Insulin-GLase, named iGL, was established and a cluster of iGL cells showed oscillatory insulin secretion that was completely synchronized in response to high glucose. Furthermore, we demonstrated the effect of an antidiabetic drug, glibenclamide, on synchronized insulin secretion from 2D- andmore » 3D-cultured iGL cells. The amount of secreted Insulin-GLase from iGL cells was also determined by a luminometer. Thus, our bioluminescence imaging method could generally be used for investigating protein secretion from living 3D-cultured cells. In addition, iGL cell line would be valuable for evaluating antidiabetic drugs. - Highlights: • An imaging method for protein secretion from 3D-cultured cells was established. • The fused protein of insulin to GLase, Insulin-GLase, was used as a reporter. • Synchronous insulin secretion was visualized in rat islets and spheroidal beta cells. • A rat beta cell line stably expressing Insulin-GLase, named iGL, was established. • Effect of an antidiabetic drug on insulin secretion was visualized in iGL cells.« less

Visualizing railroad operations : a tool for planning and monitoring railroad traffic

DOT National Transportation Integrated Search

2009-01-01

This report provides an overview of the development and technology transfer of the Railroad Traffic Planner application, a visualization tool with string line diagrams that show train positions over time. The Railroad Traffic Planner provides support...

Visualization of Sensory Neurons and Their Projections in an Upper Motor Neuron Reporter Line.

PubMed

Genç, Barış; Lagrimas, Amiko Krisa Bunag; Kuru, Pınar; Hess, Robert; Tu, Michael William; Menichella, Daniela Maria; Miller, Richard J; Paller, Amy S; Özdinler, P Hande

2015-01-01

Visualization of peripheral nervous system axons and cell bodies is important to understand their development, target recognition, and integration into complex circuitries. Numerous studies have used protein gene product (PGP) 9.5 [a.k.a. ubiquitin carboxy-terminal hydrolase L1 (UCHL1)] expression as a marker to label sensory neurons and their axons. Enhanced green fluorescent protein (eGFP) expression, under the control of UCHL1 promoter, is stable and long lasting in the UCHL1-eGFP reporter line. In addition to the genetic labeling of corticospinal motor neurons in the motor cortex and degeneration-resistant spinal motor neurons in the spinal cord, here we report that neurons of the peripheral nervous system are also fluorescently labeled in the UCHL1-eGFP reporter line. eGFP expression is turned on at embryonic ages and lasts through adulthood, allowing detailed studies of cell bodies, axons and target innervation patterns of all sensory neurons in vivo. In addition, visualization of both the sensory and the motor neurons in the same animal offers many advantages. In this report, we used UCHL1-eGFP reporter line in two different disease paradigms: diabetes and motor neuron disease. eGFP expression in sensory axons helped determine changes in epidermal nerve fiber density in a high-fat diet induced diabetes model. Our findings corroborate previous studies, and suggest that more than five months is required for significant skin denervation. Crossing UCHL1-eGFP with hSOD1G93A mice generated hSOD1G93A-UeGFP reporter line of amyotrophic lateral sclerosis, and revealed sensory nervous system defects, especially towards disease end-stage. Our studies not only emphasize the complexity of the disease in ALS, but also reveal that UCHL1-eGFP reporter line would be a valuable tool to visualize and study various aspects of sensory nervous system development and degeneration in the context of numerous diseases.

Visualizing the Histotripsy Process: Bubble Cloud-Cancer Cell Interactions in a Tissue-Mimicking Environment.

PubMed

Vlaisavljevich, Eli; Maxwell, Adam; Mancia, Lauren; Johnsen, Eric; Cain, Charles; Xu, Zhen

2016-10-01

Histotripsy is a non-invasive ultrasonic ablation method that uses cavitation to mechanically fractionate tissue into acellular debris. With a sufficient number of pulses, histotripsy can completely fractionate tissue into a liquid-appearing homogenate with no cellular structures. The location, shape and size of lesion formation closely match those of the cavitation cloud. Previous work has led to the hypothesis that the rapid expansion and collapse of histotripsy bubbles fractionate tissue by inducing large stress and strain on the tissue structures immediately adjacent to the bubbles. In the work described here, the histotripsy bulk tissue fractionation process is visualized at the cellular level for the first time using a custom-built 2-MHz transducer incorporated into a microscope stage. A layer of breast cancer cells were cultured within an optically transparent fibrin-based gel phantom to mimic cells inside a 3-D extracellular matrix. To test the hypothesis, the cellular response to single and multiple histotripsy pulses was investigated using high-speed optical imaging. Bubbles were always generated in the extracellular space, and significant cell displacement/deformation was observed for cells directly adjacent to the bubble during both bubble expansion and collapse. The largest displacements were observed during collapse for cells immediately adjacent to the bubble, with cells moving more than 150-300 μm in less than 100 μs. Cells often underwent multiple large deformations (>150% strain) over multiple pulses, resulting in the bisection of cells multiple times before complete removal. To provide theoretical support to the experimental observations, a numerical simulation was conducted using a single-bubble model, which indicated that histotripsy exerts the largest strains and cell displacements in the regions immediately adjacent to the bubble. The experimental and simulation results support our hypothesis, which helps to explain the formation of the sharp lesions formed in histotripsy therapy localized to the regions directly exposed to the bubbles. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Visualization of Data Regarding Infections Using Eye Tracking Techniques

PubMed Central

Yoon, Sunmoo; Cohen, Bevin; Cato, Kenrick D.; Liu, Jianfang; Larson, Elaine L.

2016-01-01

Objective To evaluate ease of use and usefulness for nurses of visualizations of infectious disease transmission in a hospital. Design An observational study was used to evaluate perceptions of several visualizations of data extracted from electronic health records designed using a participatory approach. Twelve nurses in the master’s program in an urban research-intensive nursing school participated in May 2015. Methods A convergent parallel mixed method was used to evaluate nurses’ perceptions on ease of use and usefulness of five visualization conveying trends in hospital infection transmission applying think-aloud, interview, and eye-tracking techniques. Findings Subjective data from the interview and think-aloud techniques indicated that participants preferred the traditional line graphs in simple data representation due to their familiarity, clarity, and easiness to read. An objective quantitative measure of eye movement analysis (444,421 gaze events) identified a high degree of participants’ attention span in infographics in all three scenarios. All participants responded with the correct answer within 1 min in comprehensive tests. Conclusions A user-centric approach was effective in developing and evaluating visualizations for hospital infection transmission. For the visualizations designed by the users, the participants were easily able to comprehend the infection visualizations on both line graphs and infographics for simple visualization. The findings from the objective comprehension test and eye movement and subjective attitudes support the feasibility of integrating user-centric visualization designs into electronic health records, which may inspire clinicians to be mindful of hospital infection transmission. Future studies are needed to investigate visualizations and motivation, and the effectiveness of visualization on infection rate. Clinical Relevance This study designed visualization images using clinical data from electronic health records applying a user-centric approach. The design insights can be applied for visualizing patient data in electronic health records. PMID:27061619

Visualization of Data Regarding Infections Using Eye Tracking Techniques.

PubMed

Yoon, Sunmoo; Cohen, Bevin; Cato, Kenrick D; Liu, Jianfang; Larson, Elaine L

2016-05-01

To evaluate ease of use and usefulness for nurses of visualizations of infectious disease transmission in a hospital. An observational study was used to evaluate perceptions of several visualizations of data extracted from electronic health records designed using a participatory approach. Twelve nurses in the master's program in an urban research-intensive nursing school participated in May 2015. A convergent parallel mixed method was used to evaluate nurses' perceptions on ease of use and usefulness of five visualization conveying trends in hospital infection transmission applying think-aloud, interview, and eye-tracking techniques. Subjective data from the interview and think-aloud techniques indicated that participants preferred the traditional line graphs in simple data representation due to their familiarity, clarity, and easiness to read. An objective quantitative measure of eye movement analysis (444,421 gaze events) identified a high degree of participants' attention span in infographics in all three scenarios. All participants responded with the correct answer within 1 min in comprehensive tests. A user-centric approach was effective in developing and evaluating visualizations for hospital infection transmission. For the visualizations designed by the users, the participants were easily able to comprehend the infection visualizations on both line graphs and infographics for simple visualization. The findings from the objective comprehension test and eye movement and subjective attitudes support the feasibility of integrating user-centric visualization designs into electronic health records, which may inspire clinicians to be mindful of hospital infection transmission. Future studies are needed to investigate visualizations and motivation, and the effectiveness of visualization on infection rate. This study designed visualization images using clinical data from electronic health records applying a user-centric approach. The design insights can be applied for visualizing patient data in electronic health records. © 2016 Sigma Theta Tau International.

Restoration of outer segments of foveal photoreceptors after resolution of central serous chorioretinopathy.

PubMed

Ojima, Yumiko; Tsujikawa, Akitaka; Yamashiro, Kenji; Ooto, Sotaro; Tamura, Hiroshi; Yoshimura, Nagahisa

2010-01-01

To study morphologically and functionally the prognosis of damaged outer segments of the foveal photoreceptor layer in eyes with resolved central serous chorioretinopathy (CSC). We studied retrospectively the medical records of 70 patients (74 eyes) with resolved CSC. Optical coherence tomography was used to detect the junctions between inner and outer segments of the photoreceptors (IS/OS) as a hallmark of the integrity of the outer photoreceptor layer. In 53 eyes (71.6%), the IS/OS line was clearly detected beneath the fovea immediately after resolution of the retinal detachment, with good visual acuity (VA). In the remaining 21 eyes (28.4%), however, the foveal IS/OS line could not be detected shortly after resolution of CSC, and VA was variable, ranging from 0.1 to 1.5 (median, 0.9). Of these 21 eyes, 15 had a follow-up examination with OCT, and in four the foveal IS/OS line was not detected at the follow-up and vision in these eyes remained poor. However, nine eyes showed recovery of the foveal IS/OS line during follow-up, and these eyes had substantial visual recovery. Immediately after resolution of active CSC, although the IS/OS line cannot be detected beneath the fovea, it often shows restoration over time, with visual recovery, though in some eyes no restoration takes place and the prognosis remains poor.

Spontaneous Resolution of Long-Standing Macular Detachment due to Optic Disc Pit with Significant Visual Improvement.

PubMed

Parikakis, Efstratios A; Chatziralli, Irini P; Peponis, Vasileios G; Karagiannis, Dimitrios; Stratos, Aimilianos; Tsiotra, Vasileia A; Mitropoulos, Panagiotis G

2014-01-01

To report a case of spontaneous resolution of a long-standing serous macular detachment associated with an optic disc pit, leading to significant visual improvement. A 63-year-old female presented with a 6-month history of blurred vision and micropsia in her left eye. Her best-corrected visual acuity was 6/24 in the left eye, and fundoscopy revealed serous macular detachment associated with optic disc pit, which was confirmed by optical coherence tomography (OCT). The patient was offered vitrectomy as a treatment alternative, but she preferred to be reviewed conservatively. Three years after initial presentation, neither macular detachment nor subretinal fluid was evident in OCT, while the inner segment/outer segment (IS/OS) junction line was intact. Her visual acuity was improved from 6/24 to 6/12 in her left eye, remaining stable at the 6-month follow-up after resolution. We present a case of spontaneous resolution of a long-standing macular detachment associated with an optic disc pit with significant visual improvement, postulating that the integrity of the IS/OS junction line may be a prognostic factor for final visual acuity and suggesting OCT as an indicator of visual prognosis and the probable necessity of a surgical management.

Lexicality, Morphological Structure, and Semantic Transparency in the Processing of German Ver-Verbs: The Complementarity of On-Line and Off-Line Evidence

ERIC Educational Resources Information Center

Schirmeier, Matthias K.; Derwing, Bruce L.; Libben, Gary

2004-01-01

Two types of experiments investigate the visual on-line and off-line processing of German ver-verbs (e.g., verbittern "to embitte"). In Experiments 1 and 2 (morphological priming), latency patterns revealed the existence of facilitation effects for the morphological conditions (BITTER-VERBITTERN and BITTERN-VERBITTERN) as compared to the neutral…

Associative visual agnosia: a case study.

PubMed

Charnallet, A; Carbonnel, S; David, D; Moreaud, O

2008-01-01

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study, an alternative account in the framework of (non abstractive) episodic models of memory.

An Evaluation of the Conservative Dual-Criterion Method for Teaching University Students to Visually Inspect AB-Design Graphs

ERIC Educational Resources Information Center

Stewart, Kelise K.; Carr, James E.; Brandt, Charles W.; McHenry, Meade M.

2007-01-01

The present study evaluated the effects of both a traditional lecture and the conservative dual-criterion (CDC) judgment aid on the ability of 6 university students to visually inspect AB-design line graphs. The traditional lecture reliably failed to improve visual inspection accuracy, whereas the CDC method substantially improved the performance…

Sticks and Stones are Bones: The Eclectic Use of Lines.

ERIC Educational Resources Information Center

Denton, Craig L.

Lines are elemental design devices that provide the primary structure for visual expressions in printed media. Gestalt principles of perception emphasize the role of the viewer, so the energy of the lines and the commercial viability of a particular design depend upon the designer's and photojournalist's understanding of both the viewer's…

Evaluation of fall armyworm resistance in maize germplasm lines using visual leaf injury rating and predator survey

USDA-ARS?s Scientific Manuscript database

After examining ear-colonizing pest resistance, 20 maize lines from the USDA-ARS germplasm enhancement of Maize (GEM) Program were evaluated for whorl-feeding fall armyworm (FAW) (Spodoptera frugiperda) resistance using four maize inbred lines as the resistant and susceptible controls. Both FAW inju...

Improvement of The Ability of Junior High School Students Thinking Through Visual Learning Assisted Geo gbra Tutorial

NASA Astrophysics Data System (ADS)

Elvi, M.; Nurjanah

2017-02-01

This research is distributed on the issue of the lack of visual thinking ability is a must-have basic ability of students in learning geometry. The purpose of this research is to investigate and elucide: 1) the enhancement of visual thinking ability of students to acquire learning assisted with geogebra tutorial learning: 2) the increase in visual thinking ability of students who obtained a model of learning assisted with geogebra and students who obtained a regular study of KAM (high, medium, and low). This research population is grade VII in Bandung Junior High School. The instruments used to collect data in this study consisted of instruments of the test and the observation sheet. The data obtained were analyzed using the test average difference i.e. Test-t and ANOVA Test one line to two lines. The results showed that: 1) the attainment and enhancement of visual thinking ability of students to acquire learning assisted geogebra tutorial better than students who acquire learning; 2) there may be differences of visual upgrade thinking students who acquire the learning model assisted with geogebra tutorial earn regular learning of KAM (high, medium and low).

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

Alekseev, I. S.; Ivanov, I. E.; Strelkov, P. S., E-mail: strelkov@fpl.gpi.ru

A method based on the detection of emission of a dielectric screen with metal microinclusions in open air is applied to visualize the transverse structure of a high-power microwave beam. In contrast to other visualization techniques, the results obtained in this work provide qualitative information not only on the electric field strength, but also on the structure of electric field lines in the microwave beam cross section. The interpretation of the results obtained with this method is confirmed by numerical simulations of the structure of electric field lines in the microwave beam cross section by means of the CARAT code.

40 CFR 312.27 - Visual inspections of the facility and of adjoining properties.

Code of Federal Regulations, 2010 CFR

2010-07-01

... inspection of adjoining properties, from the subject property line, public rights-of-way, or other vantage... accessible vantage point (such as the property line or public road for small properties); (2) Documentation...

Louisville, KY, USA

NASA Image and Video Library

1973-06-22

SL2-10-260 (22 June 1973) --- The meandering Ohio River bisecting this image is the border between Kentucky and Indiana. Louisville, KY (38.5N, 86.0W) on the south shore, is the main city seen in this predominately agricultural region where much of the native hardwood forests have been preserved in the hilly terrain. The main crops in this region include corn, alfalfa, wheat and soybeans. The dark rectangle in south Indiana near the river is The U.S. Army's Jefferson Proving Ground. Photo credit: NASA

Colorado as seen from STS-58

NASA Technical Reports Server (NTRS)

1993-01-01

An oblique westward view, across the wheat fields and cattle pastures, of eastern Colorado to the Front Range of the Rocky Mountains. Denver is bisected at the center of the right edge of the frame. Pikes Peak and Colorado Springs are left of center, and the Arkansas River Valley with Canyon City and the Royal Gorge are along the left edge of the frame. This view shows the startling contrast between the nearly-flat High Plains and the ancient geological uplift of the Rockies.

Proposed Infantry Division Force (9th) Conversion; Maneuver Damage, Erosion and Natural Resources Assessment Yakima Firing Center, Washington. Volume 1. Main Text

DTIC Science & Technology

1990-08-01

dock, bulrushes (Scirpus americanus and 5._ microcarpus), water parsley (Oenanthe sarmentosa), duckweed 106 ( Lemna minor ), horsetails (Equisetum spp...particles to finer sizes as well as truncating and bisecting of aeolian land forms. b. The effects of maneuvers on the threshold are minor compared to the...Agropyron spicatum and Sandberg bluegrass (Poa sandbergii). A mixture of " minor " shrubs can also be found in this cover type, including green rabbitbush

Modeling the Effects of Varying the Capacitance, Resistance, Temperature, and Frequency Dependence for HTS Josephson Junctions, DC SQUIDs and DC bi-SQUIDS

DTIC Science & Technology

2014-09-01

junction is a thin layer of insulating material sep- arating two superconductors that is thin enough for electrons to tunnel through. Two Josephson...can sense minute magnetic fields approaching 1015 Tesla. These SQUIDs can be arranged in arrays with different coupling schemes and parameter values to...different material and/or method on the bisecting Josephson junction for high temperature superconductor (HTS) YBa2Cu3O7 (YBCO) bi-SQUIDs. This

Inner and outer segment junction (IS/OS line) integrity in ocular Behçet's disease.

PubMed

Yüksel, Harun; Türkcü, Fatih M; Sahin, Muhammed; Cinar, Yasin; Cingü, Abdullah K; Ozkurt, Zeynep; Sahin, Alparslan; Ari, Seyhmus; Caça, Ihsan

2014-08-01

In this study, we examined the spectral domain optical coherence tomography (OCT) findings of ocular Behçet's disease (OB) in patients with inactive uveitis. Specifically, we analyzed the inner and outer segment junction (IS/OS line) integrity and the effect of disturbed IS/OS line integrity on visual acuity. Patient files and OCT images of OB patients who had been followed-up between January and June of the year 2013 at the Dicle University Eye Clinic were evaluated retrospectively. Sixty-six eyes of 39 patients were included the study. OCT examination of the patients with inactive OB revealed that approximately 25% of the patients had disturbed IS/OS and external limiting membrane (EML) line integrity, lower visual acuity (VA), and lower macular thickness than others. Linear regression analysis revealed that macular thickness was not an independent variable for VA. In contrast, the IS/OS line integrity was an independent variable for VA in inactive OB patients. In this study, we showed that the IS/OS line integrity was an independent variable for VA in inactive OB patients. Further prospective studies are needed to evaluate the integrity of the IS/OS line in OB patients.

IUE observations of symbiotic stars

NASA Technical Reports Server (NTRS)

Hack, M.

1982-01-01

The main photometric and spectroscopic characteristics in the ultraviolet and visual range of the most extensively studied symbiotic stars are reviewed. The main data obtained with IUE concern: (1) the determination of the shape of the UV continuum, which, in some cases, proves without doubt the presence of a hot companion; and the determination of the interstellar extinction by means of the lambda 2200 feature; (2) the measurement of emission lines, which enables us to derive the electron temperature and density of the circumstellar envelope, and, taken together with those lines observed in the visual, give more complete information on which spectroscopic mechanisms operate in the envelope; (3) the observation of absorption lines in the UV, which are present in just a few cases.

Observation of electromigration in a Cu thin line by in situ coherent x-ray diffraction microscopy

NASA Astrophysics Data System (ADS)

Takahashi, Yukio; Nishino, Yoshinori; Furukawa, Hayato; Kubo, Hideto; Yamauchi, Kazuto; Ishikawa, Tetsuya; Matsubara, Eiichiro

2009-06-01

Electromigration (EM) in a 1-μm-thick Cu thin line was investigated by in situ coherent x-ray diffraction microscopy (CXDM). Characteristic x-ray speckle patterns due to both EM-induced voids and thermal deformation in the thin line were observed in the coherent x-ray diffraction patterns. Both parts of the voids and the deformation were successfully visualized in the images reconstructed from the diffraction patterns. This result not only represents the first demonstration of the visualization of structural changes in metallic materials by in situ CXDM but is also an important step toward studying the structural dynamics of nanomaterials using x-ray free-electron lasers in the near future.

Control of humanoid robot via motion-onset visual evoked potentials

PubMed Central

Li, Wei; Li, Mengfan; Zhao, Jing

2015-01-01

This paper investigates controlling humanoid robot behavior via motion-onset specific N200 potentials. In this study, N200 potentials are induced by moving a blue bar through robot images intuitively representing robot behaviors to be controlled with mind. We present the individual impact of each subject on N200 potentials and discuss how to deal with individuality to obtain a high accuracy. The study results document the off-line average accuracy of 93% for hitting targets across over five subjects, so we use this major component of the motion-onset visual evoked potential (mVEP) to code people's mental activities and to perform two types of on-line operation tasks: navigating a humanoid robot in an office environment with an obstacle and picking-up an object. We discuss the factors that affect the on-line control success rate and the total time for completing an on-line operation task. PMID:25620918

Attentional limits on the perception and memory of visual information.

PubMed

Palmer, J

1990-05-01

Attentional limits on perception and memory were measured by the decline in performance with increasing numbers of objects in a display. Multiple objects were presented to Ss who discriminated visual attributes. In a representative condition, 4 lines were briefly presented followed by a single line in 1 of the same locations. Ss were required to judge if the single line in the 2nd display was longer or shorter than the line in the corresponding location of the 1st display. The length difference threshold was calculated as a function of the number of objects. The difference thresholds doubled when the number of objects was increased from 1 to 4. This effect was generalized in several ways, and nonattentional explanations were ruled out. Further analyses showed that the attentional processes must share information from at least 4 objects and can be described by a simple model.

Real-time biscuit tile image segmentation method based on edge detection.

PubMed

Matić, Tomislav; Aleksi, Ivan; Hocenski, Željko; Kraus, Dieter

2018-05-01

In this paper we propose a novel real-time Biscuit Tile Segmentation (BTS) method for images from ceramic tile production line. BTS method is based on signal change detection and contour tracing with a main goal of separating tile pixels from background in images captured on the production line. Usually, human operators are visually inspecting and classifying produced ceramic tiles. Computer vision and image processing techniques can automate visual inspection process if they fulfill real-time requirements. Important step in this process is a real-time tile pixels segmentation. BTS method is implemented for parallel execution on a GPU device to satisfy the real-time constraints of tile production line. BTS method outperforms 2D threshold-based methods, 1D edge detection methods and contour-based methods. Proposed BTS method is in use in the biscuit tile production line. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Drawing the line between constituent structure and coherence relations in visual narratives

PubMed Central

Cohn, Neil; Bender, Patrick

2016-01-01

Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of Visual Narrative Grammar posits that hierarchic “grammatical” structures operate at the discourse level using categorical roles for images, which may or may not co-occur with shifts in coherence. We therefore examined the relationship between narrative structure and coherence shifts in the segmentation of visual narrative sequences using a “segmentation task” where participants drew lines between images in order to divide them into sub-episodes. We used regressions to analyze the influence of the expected constituent structure boundary, narrative categories, and semantic coherence relationships on the segmentation of visual narrative sequences. Narrative categories were a stronger predictor of segmentation than linear coherence relationships between panels, though both influenced participants’ divisions. Altogether, these results support the theory that meaningful sequential images use a narrative grammar that extends above and beyond linear semantic shifts between discourse units. PMID:27709982

Drawing the line between constituent structure and coherence relations in visual narratives.

PubMed

Cohn, Neil; Bender, Patrick

2017-02-01

Theories of visual narrative understanding have often focused on the changes in meaning across a sequence, like shifts in characters, spatial location, and causation, as cues for breaks in the structure of a discourse. In contrast, the theory of visual narrative grammar posits that hierarchic "grammatical" structures operate at the discourse level using categorical roles for images, which may or may not co-occur with shifts in coherence. We therefore examined the relationship between narrative structure and coherence shifts in the segmentation of visual narrative sequences using a "segmentation task" where participants drew lines between images in order to divide them into subepisodes. We used regressions to analyze the influence of the expected constituent structure boundary, narrative categories, and semantic coherence relationships on the segmentation of visual narrative sequences. Narrative categories were a stronger predictor of segmentation than linear coherence relationships between panels, though both influenced participants' divisions. Altogether, these results support the theory that meaningful sequential images use a narrative grammar that extends above and beyond linear semantic shifts between discourse units. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Selection for associative learning of colour stimuli reveals correlated evolution of this learning ability across multiple stimuli and rewards.

PubMed

Liefting, Maartje; Hoedjes, Katja M; Lann, Cécile Le; Smid, Hans M; Ellers, Jacintha

2018-05-16

We are only starting to understand how variation in cognitive ability can result from local adaptations to environmental conditions. A major question in this regard is to what extent selection on cognitive ability in a specific context affects that ability in general through correlated evolution. To address this question we performed artificial selection on visual associative learning in female Nasonia vitripennis wasps. Using appetitive conditioning in which a visual stimulus was offered in association with a host reward, the ability to learn visual associations was enhanced within 10 generations of selection. To test for correlated evolution affecting this form of learning, the ability to readily form learned associations in females was also tested using an olfactory instead of a visual stimulus in the appetitive conditioning. Additionally, we assessed whether the improved associative learning ability was expressed across sexes by colour-conditioning males with a mating reward. Both females and males from the selected lines consistently demonstrated an increased associative learning ability compared to the control lines, independent of learning context or conditioned stimulus. No difference in relative volume of brain neuropils was detected between the selected and control lines. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

High-quality and interactive animations of 3D time-varying vector fields.

PubMed

Helgeland, Anders; Elboth, Thomas

2006-01-01

In this paper, we present an interactive texture-based method for visualizing three-dimensional unsteady vector fields. The visualization method uses a sparse and global representation of the flow, such that it does not suffer from the same perceptual issues as is the case for visualizing dense representations. The animation is made by injecting a collection of particles evenly distributed throughout the physical domain. These particles are then tracked along their path lines. At each time step, these particles are used as seed points to generate field lines using any vector field such as the velocity field or vorticity field. In this way, the animation shows the advection of particles while each frame in the animation shows the instantaneous vector field. In order to maintain a coherent particle density and to avoid clustering as time passes, we have developed a novel particle advection strategy which produces approximately evenly-spaced field lines at each time step. To improve rendering performance, we decouple the rendering stage from the preceding stages of the visualization method. This allows interactive exploration of multiple fields simultaneously, which sets the stage for a more complete analysis of the flow field. The final display is rendered using texture-based direct volume rendering.

Object-based Encoding in Visual Working Memory: Evidence from Memory-driven Attentional Capture.

PubMed

Gao, Zaifeng; Yu, Shixian; Zhu, Chengfeng; Shui, Rende; Weng, Xuchu; Li, Peng; Shen, Mowei

2016-03-09

Visual working memory (VWM) adopts a specific manner of object-based encoding (OBE) to extract perceptual information: Whenever one feature-dimension is selected for entry into VWM, the others are also extracted. Currently most studies revealing OBE probed an 'irrelevant-change distracting effect', where changes of irrelevant-features dramatically affected the performance of the target feature. However, the existence of irrelevant-feature change may affect participants' processing manner, leading to a false-positive result. The current study conducted a strict examination of OBE in VWM, by probing whether irrelevant-features guided the deployment of attention in visual search. The participants memorized an object's colour yet ignored shape and concurrently performed a visual-search task. They searched for a target line among distractor lines, each embedded within a different object. One object in the search display could match the shape, colour, or both dimensions of the memory item, but this object never contained the target line. Relative to a neutral baseline, where there was no match between the memory and search displays, search time was significantly prolonged in all match conditions, regardless of whether the memory item was displayed for 100 or 1000 ms. These results suggest that task-irrelevant shape was extracted into VWM, supporting OBE in VWM.

Temperature distribution in a stellar atmosphere diagnostic basis

NASA Technical Reports Server (NTRS)

Jefferies, J. T.; Morrison, N. D.

1973-01-01

A stellar chromosphere is considered a region where the temperature increases outward and where the temperature structure of the gas controls the shape of the spectral lines. It is shown that lines which have collision-dominated source sink terms, like the Ca(+) and Mg(+) H and K lines, can be used to obtain the distribution of temperature with height from observed line profiles. Intrinsic emission lines and geometrical emission lines are found in spectral regions where the continuum is depressed. In visual regions, where the continuum is not depressed, emission core in absorption lines are attributed to reflections of intrinsic emission lines.

Comparing the Impact of Refractive and Nonrefractive Vision Loss on Functioning and Disability: The Salisbury Eye Evaluation.

PubMed

Zebardast, Nazlee; Swenor, Bonnielin K; van Landingham, Suzanne W; Massof, Robert W; Munoz, Beatriz; West, Sheila K; Ramulu, Pradeep Y

2015-06-01

To compare the effects of uncorrected refractive error (URE) and nonrefractive visual impairment (VI) on performance and disability measures. Cross-sectional, population-based study. A total of 2469 individuals with binocular presenting visual acuity (PVA) of ≥ 20/80 who participated in the first round of the Salisbury Eye Evaluation study. The URE was defined as binocular PVA of ≤ 20/30, improving to >20/30 with subjective refraction. The VI was defined as post-refraction binocular best-corrected visual acuity (BCVA) of ≤ 20/30. The visual acuity decrement due to VI was calculated as the difference between BCVA and 20/30, whereas visual acuity due to URE was taken as the difference between PVA and BCVA. Multivariable regression analyses were used to assess the disability impact of (1) vision status (VI, URE, or normal vision) using the group with normal vision as reference and (2) a 1-line decrement in acuity due to VI or URE. Objective measures of visual function were obtained from timed performance of mobility and near vision tasks, self-reported driving cessation, and self-reported visual difficulty measured by the Activities of Daily Vision (ADV) scale. The ADV responses were analyzed using Rasch analysis to determine visual ability. Compared with individuals with normal vision, subjects with VI (n = 191) had significantly poorer objective and subjective visual functioning in all metrics examined (P < 0.05), whereas subjects with URE (n = 132) demonstrated slower walking speeds, slower near task performance, more frequent driving cessation, and lower ADV scores (P < 0.05), but did not demonstrate slower stair climbing or descent speed. For all functional metrics evaluated, the impact of VI was greater than the impact of URE. The impact of a 1-line VA decrement due to VI was associated with greater deficits in mobility measures and driving cessation when compared with a 1-line VA decrement due to URE. Visual impairment is associated with greater disability than URE across a wide variety of functional measures, even in analyses adjusting for the severity of vision loss. Refractive and nonrefractive vision loss should be distinguished in studies evaluating visual disability and be understood to have differing consequences. Copyright © 2015 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Braking, Wheeled Vehicles. Test Operations Procedure (TOP)

DTIC Science & Technology

2008-05-20

actuated. 2. Hydraulic System Procedure: Visually inspect the lines, hoses , master cylinder and cap. Reject the vehicle if: • Lines and... hoses are leaking, welded, cracked, chafed, flattened, insecurely mounted or have restricted sections. • Repairs to lines and hoses have been made...608 20 May 2008 D-3 HAZARDOUS CONDITION • Any brake hose or line seeps or swells under pressure. • Any brake hose is cracked to the second

Associative Visual Agnosia: A Case Study

PubMed Central

Charnallet, A.; Carbonnel, S.; David, D.; Moreaud, O.

2008-01-01

We report a case of massive associative visual agnosia. In the light of current theories of identification and semantic knowledge organization, a deficit involving both levels of structural description system and visual semantics must be assumed to explain the case. We suggest, in line with a previous case study [1], an alternative account in the framework of (non abstractive) episodic models of memory [4]. PMID:18413915

The representation of visual depth perception based on the plenoptic function in the retina and its neural computation in visual cortex V1.

PubMed

Songnian, Zhao; Qi, Zou; Chang, Liu; Xuemin, Liu; Shousi, Sun; Jun, Qiu

2014-04-23

How it is possible to "faithfully" represent a three-dimensional stereoscopic scene using Cartesian coordinates on a plane, and how three-dimensional perceptions differ between an actual scene and an image of the same scene are questions that have not yet been explored in depth. They seem like commonplace phenomena, but in fact, they are important and difficult issues for visual information processing, neural computation, physics, psychology, cognitive psychology, and neuroscience. The results of this study show that the use of plenoptic (or all-optical) functions and their dual plane parameterizations can not only explain the nature of information processing from the retina to the primary visual cortex and, in particular, the characteristics of the visual pathway's optical system and its affine transformation, but they can also clarify the reason why the vanishing point and line exist in a visual image. In addition, they can better explain the reasons why a three-dimensional Cartesian coordinate system can be introduced into the two-dimensional plane to express a real three-dimensional scene. 1. We introduce two different mathematical expressions of the plenoptic functions, Pw and Pv that can describe the objective world. We also analyze the differences between these two functions when describing visual depth perception, that is, the difference between how these two functions obtain the depth information of an external scene.2. The main results include a basic method for introducing a three-dimensional Cartesian coordinate system into a two-dimensional plane to express the depth of a scene, its constraints, and algorithmic implementation. In particular, we include a method to separate the plenoptic function and proceed with the corresponding transformation in the retina and visual cortex.3. We propose that size constancy, the vanishing point, and vanishing line form the basis of visual perception of the outside world, and that the introduction of a three-dimensional Cartesian coordinate system into a two dimensional plane reveals a corresponding mapping between a retinal image and the vanishing point and line.

The representation of visual depth perception based on the plenoptic function in the retina and its neural computation in visual cortex V1

PubMed Central

2014-01-01

Background How it is possible to “faithfully” represent a three-dimensional stereoscopic scene using Cartesian coordinates on a plane, and how three-dimensional perceptions differ between an actual scene and an image of the same scene are questions that have not yet been explored in depth. They seem like commonplace phenomena, but in fact, they are important and difficult issues for visual information processing, neural computation, physics, psychology, cognitive psychology, and neuroscience. Results The results of this study show that the use of plenoptic (or all-optical) functions and their dual plane parameterizations can not only explain the nature of information processing from the retina to the primary visual cortex and, in particular, the characteristics of the visual pathway’s optical system and its affine transformation, but they can also clarify the reason why the vanishing point and line exist in a visual image. In addition, they can better explain the reasons why a three-dimensional Cartesian coordinate system can be introduced into the two-dimensional plane to express a real three-dimensional scene. Conclusions 1. We introduce two different mathematical expressions of the plenoptic functions, P w and P v that can describe the objective world. We also analyze the differences between these two functions when describing visual depth perception, that is, the difference between how these two functions obtain the depth information of an external scene. 2. The main results include a basic method for introducing a three-dimensional Cartesian coordinate system into a two-dimensional plane to express the depth of a scene, its constraints, and algorithmic implementation. In particular, we include a method to separate the plenoptic function and proceed with the corresponding transformation in the retina and visual cortex. 3. We propose that size constancy, the vanishing point, and vanishing line form the basis of visual perception of the outside world, and that the introduction of a three-dimensional Cartesian coordinate system into a two dimensional plane reveals a corresponding mapping between a retinal image and the vanishing point and line. PMID:24755246

Wavefront-optimized laser in situ keratomileusis with the Allegretto Wave Eye-Q excimer laser and the FEMTO LDV Crystal Line femtosecond laser: 6 month visual and refractive results.

PubMed

Ziaei, Mohammed; Mearza, Ali A; Allamby, David

2015-08-01

To present the first reported series of patients undergoing myopic LASIK with the FEMTO LDV Crystal Line femtosecond laser and the WaveLight Allegretto Eye-Q excimer laser. We report the uncorrected and corrected distance visual acuity (UDVA and CDVA), refractive predictability, efficacy and safety of laser in situ keratomileusis (LASIK) performed with the above laser platforms. This prospective interventional case series study evaluated consecutive eyes with low to moderate myopic astigmatism that underwent LASIK with the FEMTO LDV Crystal Line femtosecond laser and the WaveLight Allegretto Eye-Q 400 Hz excimer laser. Visual and refractive changes as well as complications were evaluated after wavefront-optimized laser treatment. Four hundred and forty four patients (887 eyes) reached the 6-month time gate. Mean age at time of procedure was 31 years (range: 20-59). Mean pre-op spherical-equivalent (SE) was -3.44 diopters (D)±1.34D (range: -0.50 to -7.00) whilst the postoperative spherical equivalent decreased to -0.08±0.31D (range -2.25 to 1.00). At 6-month follow up, 96.9% of patients had monocular uncorrected distance visual acuity of 20/20 or better with 95.2% of patients within ±0.5D of intended refractive outcome. All patients achieved 20/20 binocular distance uncorrected visual acuity. No significant intra-operative or postoperative complications were encountered during the 6-month follow-up period. The combination of the above laser platforms provides safe, effective and predictable results in correcting compound myopic astigmatism with excellent visual outcomes. Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Visual search performance on an lcd monitor: effects of color combination of figure and icon background, shape of icon, and line width of icon border.

PubMed

Huang, Kuo-Chen; Chiu, Tsai-Lan

2007-04-01

This study investigated the effects of color combinations for the figure/icon background, icon shape, and line width of the icon border on visual search performance on a liquid crystal display screen. In a circular stimulus array, subjects had to search for a target item which had a diameter of 20 cm and included one target and 19 distractors. Analysis showed that the icon shape significantly affected search performance. The correct response time was significantly shorter for circular icons than for triangular icons, for icon borders with a line width of 3 pixels than for 1 or 2 pixels, and for 2 pixels than for 1 pixel. The color combination also significantly affected the visual search performance: white/yellow, white/blue, black-red, and black/ yellow color combinations for the figure/icon background had shorter correct response times compared to yellow/blue, red/green, yellow/green, and blue/red. However, no effects were found for the line width of the icon border or the icon shape on the error rate. Results have implications for graphics-based design of interfaces, such as for mobile phones, Web sites, and PDAs, as well as complex industrial processes.

Visual detection of multiple genetically modified organisms in a capillary array.

PubMed

Shao, Ning; Chen, Jianwei; Hu, Jiaying; Li, Rong; Zhang, Dabing; Guo, Shujuan; Hui, Junhou; Liu, Peng; Yang, Litao; Tao, Sheng-Ce

2017-01-31

There is an urgent need for rapid, low-cost multiplex methodologies for the monitoring of genetically modified organisms (GMOs). Here, we report a C[combining low line]apillary A[combining low line]rray-based L[combining low line]oop-mediated isothermal amplification for M[combining low line]ultiplex visual detection of nucleic acids (CALM) platform for the simple and rapid monitoring of GMOs. In CALM, loop-mediated isothermal amplification (LAMP) primer sets are pre-fixed to the inner surface of capillaries. The surface of the capillary array is hydrophobic while the capillaries are hydrophilic, enabling the simultaneous loading and separation of the LAMP reaction mixtures into each capillary by capillary forces. LAMP reactions in the capillaries are then performed in parallel, and the results are visually detected by illumination with a hand-held UV device. Using CALM, we successfully detected seven frequently used transgenic genes/elements and five plant endogenous reference genes with high specificity and sensitivity. Moreover, we found that measurements of real-world blind samples by CALM are consistent with results obtained by independent real-time PCRs. Thus, with an ability to detect multiple nucleic acids in a single easy-to-operate test, we believe that CALM will become a widely applied technology in GMO monitoring.

In-line monitoring of pellet coating thickness growth by means of visual imaging.

PubMed

Oman Kadunc, Nika; Sibanc, Rok; Dreu, Rok; Likar, Boštjan; Tomaževič, Dejan

2014-08-15

Coating thickness is the most important attribute of coated pharmaceutical pellets as it directly affects release profiles and stability of the drug. Quality control of the coating process of pharmaceutical pellets is thus of utmost importance for assuring the desired end product characteristics. A visual imaging technique is presented and examined as a process analytic technology (PAT) tool for noninvasive continuous in-line and real time monitoring of coating thickness of pharmaceutical pellets during the coating process. Images of pellets were acquired during the coating process through an observation window of a Wurster coating apparatus. Image analysis methods were developed for fast and accurate determination of pellets' coating thickness during a coating process. The accuracy of the results for pellet coating thickness growth obtained in real time was evaluated through comparison with an off-line reference method and a good agreement was found. Information about the inter-pellet coating uniformity was gained from further statistical analysis of the measured pellet size distributions. Accuracy and performance analysis of the proposed method showed that visual imaging is feasible as a PAT tool for in-line and real time monitoring of the coating process of pharmaceutical pellets. Copyright © 2014 Elsevier B.V. All rights reserved.

33 CFR 137.65 - Visual inspections of the facility, the real property on which the facility is located, and...

Code of Federal Regulations, 2010 CFR

2010-07-01

... rights-of-way, or other vantage point (e.g., aerial photography), including a visual inspection of areas... the facility is located from the nearest accessible vantage point, such as the property line or public...

Radial velocities of southern visual multiple stars

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

Tokovinin, Andrei; Pribulla, Theodor; Fischer, Debra, E-mail: atokovinin@ctio.noao.edu, E-mail: pribulla@ta3.sk, E-mail: debra.fischer@gmail.com

2015-01-01

High-resolution spectra of visual multiple stars were taken in 2008–2009 to detect or confirm spectroscopic subsystems and to determine their orbits. Radial velocities of 93 late-type stars belonging to visual multiple systems were measured by numerical cross-correlation. We provide the individual velocities, the width, and the amplitude of the Gaussians that approximate the correlations. The new information on the multiple systems resulting from these data is discussed. We discovered double-lined binaries in HD 41742B, HD 56593C, and HD 122613AB, confirmed several other known subsystems, and constrained the existence of subsystems in some visual binaries where both components turned out tomore » have similar velocities. The orbits of double-lined subsystems with periods of 148 and 13 days are computed for HD 104471 Aa,Ab and HD 210349 Aa,Ab, respectively. We estimate individual magnitudes and masses of the components in these triple systems and update the outer orbit of HD 104471 AB.« less

Visual Acuity Improvement of Amblyopia in an Adult With Levodopa/Carbidopa Treatment.

PubMed

Orge, Faruk H; Dar, Suhail A

2015-09-09

Amblyopia is the leading cause of visual loss in children, affecting 2% to 3% of the population. Occlusion of the dominant eye is the primary and best treatment, although efficacy decreases after 6 years of age. As a result, levodopa/carbidopa has been explored as an adjunct to conventional therapy and has been shown to have an immediate impact on visual acuity. Several studies to date have shown mixed results on the benefit of supplementing occlusion therapy with levodopa/carbidopa, although they have primarily studied children. The authors describe the oldest patient (46 years old) documented in the literature to have shown improvement in visual acuity using levodopa/carbidopa. He was given a 16-week course at a dose in line with previous studies while being effectively occluded full time due to a glaucomatous right eye with no light perception. On 3-month follow-up, his left eye improved two lines and stabilized at 6 months. Copyright 2015, SLACK Incorporated.

Handmade Multitextured Maps.

ERIC Educational Resources Information Center

Trevelyan, Simon

1984-01-01

Tactile maps for visually impaired persons can be made by drawing lines with an aqueous adhesive solution, dusting with thermoengraving powder, and exposing the card to a source of intense heat (such as a heat gun or microwave oven). A raised line map results. (CL)

Evaluation of helmet-mounted display targeting symbology based on eye tracking technology

NASA Astrophysics Data System (ADS)

Wang, Lijing; Wen, Fuzhen; Ma, Caixin; Zhao, Shengchu; Liu, Xiaodong

2014-06-01

The purpose of this paper is to find the Target Locator Lines (TLLs) which perform best by contrasting and comparing experiment based on three kinds of TTLs of fighter HMD. 10 university students, male, with an average age of 21-23, corrected visual acuity 1.5, participated in the experiment. In the experiment, head movement data was obtained by TrackIR. The geometric relationship between the coordinates of the real world and coordinates of the visual display was obtained by calculating the distance from viewpoint to midpoint of both eyes and the head movement data. Virtual helmet system simulation experiment environment was created by drawing TLLs of fighter HMD in the flight simulator visual scene. In the experiment, eye tracker was used to record the time and saccade trajectory. The results were evaluated by the duration of the time and saccade trajectory. The results showed that the symbol"locator line with digital vector length indication" cost most time and had the longest length of the saccade trajectory. It is the most ineffective and most unacceptable way. "Locator line with extending head vector length symbol" cost less time and had less length of the saccade trajectory. It is effective and acceptable;"Locator line with reflected vector length symbol" cost the least time and had the least length of the saccade trajectory. It is the most effective and most acceptable way. "Locator line with reflected vector length symbol" performs best. The results will provide reference value for the research of TTLs in future.

High-Spatial-Resolution OH PLIF Visualization in a Cavity-Stabilized Ethylene-Air Turbulent Flame

NASA Technical Reports Server (NTRS)

Geipel, Clayton M.; Rockwell, Robert D.; Chelliah, Harsha K.; Cutler, Andrew D.; Spelker, Christopher A.; Hashem, Zeid; Danehy, Paul M.

2017-01-01

High-spatial-resolution OH planar laser-induced fluorescence was measured for a premixed ethylene-air turbulent flame in an electrically-heated Mach 2 continuous-flow facility (University of Virginia Supersonic Combustion Facility, Configuration E.) The facility comprised a Mach 2 nozzle, an isolator with flush-wall fuel injectors, a combustor with optical access, and an extender. The flame was anchored at a cavity flameholder with a backward-facing step of height 9 mm. The temperature-insensitive Q1(8) transition of OH was excited using laser light of wavelength 283.55 nm. A spatial filter was used to create a laser sheet approximately 25 microns thick based on full-width at half maximum (FWHM). Extension tubes increased the magnification of an intensified camera system, achieving in-plane resolution of 40 microns based on a 50% modulation transfer function (MTF). The facility was tested with total temperature 1200 K, total pressure 300 kPa, local fuel/air equivalence ratios of approximately 0.4, and local Mach number of approximately 0.73 in the combustor. A test case with reduced total temperature and another with reduced equivalence ratio were also tested. PLIF images were acquired along a streamwise plane bisecting the cavity flameholder, from the backward facing step to 120 mm downstream of the step. The smallest observed features in the flow had width of approximately 110 microns. Flame surface density was calculated for OH PLIF images.

Integration of a vision-based tracking platform, visual instruction, and error analysis models for an efficient billiard training system

NASA Astrophysics Data System (ADS)

Shih, Chihhsiong; Hsiung, Pao-Ann; Wan, Chieh-Hao; Koong, Chorng-Shiuh; Liu, Tang-Kun; Yang, Yuanfan; Lin, Chu-Hsing; Chu, William Cheng-Chung

2009-02-01

A billiard ball tracking system is designed to combine with a visual guide interface to instruct users for a reliable strike. The integrated system runs on a PC platform. The system makes use of a vision system for cue ball, object ball and cue stick tracking. A least-squares error calibration process correlates the real-world and the virtual-world pool ball coordinates for a precise guidance line calculation. Users are able to adjust the cue stick on the pool table according to a visual guidance line instruction displayed on a PC monitor. The ideal visual guidance line extended from the cue ball is calculated based on a collision motion analysis. In addition to calculating the ideal visual guide, the factors influencing selection of the best shot among different object balls and pockets are explored. It is found that a tolerance angle around the ideal line for the object ball to roll into a pocket determines the difficulty of a strike. This angle depends in turn on the distance from the pocket to the object, the distance from the object to the cue ball, and the angle between these two vectors. Simulation results for tolerance angles as a function of these quantities are given. A selected object ball was tested extensively with respect to various geometrical parameters with and without using our integrated system. Players with different proficiency levels were selected for the experiment. The results indicate that all players benefit from our proposed visual guidance system in enhancing their skills, while low-skill players show the maximum enhancement in skill with the help of our system. All exhibit enhanced maximum and average hit-in rates. Experimental results on hit-in rates have shown a pattern consistent with that of the analysis. The hit-in rate is thus tightly connected with the analyzed tolerance angles for sinking object balls into a target pocket. These results prove the efficiency of our system, and the analysis results can be used to attain an efficient game-playing strategy.

Kinetics of N-Glycan Release from Human Immunoglobulin G (IgG) by PNGase F: All Glycans Are Not Created Equal.

PubMed

Huang, Yining; Orlando, Ron

2017-12-01

The biologic activity of IgG molecules is modulated by its crystallizable fragment N-glycosylation, and thus, the analysis of IgG glycosylation is critical. A standard approach to analyze glycosylation of IgGs involves the release of the N-glycans by the enzyme peptide N-glycosidase F, which cleaves the linkage between the asparagine residue and innermost N-acetylglucosamine (GlcNAc) of all N-glycans except those containing a 3-linked fucose attached to the reducing terminal GlcNAc residue. The importance of obtaining complete glycan release for accurate quantitation led us to investigate the kinetics of this de-glycosylation reaction for IgG glycopeptides and to determine the effect of glycan structure and amino acid sequence on the rate of glycan release from glycopeptides of IgGs. This study revealed that the slight differences in amino acid sequences did not lead to a statistically different deglycosylation rate. However, statistically significant differences in the deglycosylation rate constants were observed between glycopeptides differing only in glycan structure ( i.e. , nonfucosylated, fucosylated, bisecting-GlcNAc, sialylated, etc .). For example, a single sialic acid residue was found to decrease the rate by a factor of 3. Similar reductions in rate were associated with the presence of a bisecting-GlcNAc. We predict the differences in release kinetics can lead to significant quantitative variations of the glycosylation study of IgGs.

The Yin and the Yang of visuo-spatial neglect: a case study.

PubMed

Marshall, J C; Halligan, P W

1994-09-01

We report a patient (R.B.) who has shown gross left visuo-spatial neglect over the 3 years since he sustained a right parietal infarct. Although his neglect is severe on such tasks as line bisection, cancellation, and drawing, there are some domains of preserved perceptual performance: he can perceive subjective contours, he can use lateral symmetry as a cue to figure-ground segregation, and he benefits from some forms of global cueing. In a series of five experiments, we show that R.B. has a selective inability to analyse and copy accurately the left contours of geometric nonsense-figures. These results hold even when there is a single vertical contour (to be copied) that divides a rectangle or a circle into two sub-figures; this physically-identical boundary is copied more accurately when it is cued as the right edge of the left sub-figure than when it is cued as the left edge of the right sub-figure. These effects are not influenced by a manipulation in which R.B. is required to trace the outline of the relevant sub-figure with his finger immediately prior to drawing his copy. The results are interpreted in terms of classical Gestalt theories of figure-ground assignment. Pre-attentive (global) figure-ground parsing is basically intact; but when focal attention is demanded, only the right side of an object is coded as figure.

3D Visualizations of Abstract DataSets

DTIC Science & Technology

2010-08-01

contrasts no shadows, drop shadows and drop lines. 15. SUBJECT TERMS 3D displays, 2.5D displays, abstract network visualizations, depth perception , human...altitude perception in airspace management and airspace route planning—simulated reality visualizations that employ altitude and heading as well as...cues employed by display designers for depicting real-world scenes on a flat surface can be applied to create a perception of depth for abstract

The Effect of Visual Cueing and Control Design on Children's Reading Achievement of Audio E-Books with Tablet Computers

ERIC Educational Resources Information Center

Wang, Pei-Yu; Huang, Chung-Kai

2015-01-01

This study aims to explore the impact of learner grade, visual cueing, and control design on children's reading achievement of audio e-books with tablet computers. This research was a three-way factorial design where the first factor was learner grade (grade four and six), the second factor was e-book visual cueing (word-based, line-based, and…

Eye-hand exercise: new variant in amblyopia management.

PubMed

Svĕrák, J; Peregrin, J; Juran, J

1990-01-01

A total of 50 children with unilateral amblyopia was treated by short term 10 minute-lasting weekly occlusions of visually well eye. During the occlusion the child is providing the intensive detailed activities under patient's supervision. After an approximately half-a-year lasting interval, the "eye-hand" exercise resulted in the mean improvement of visual acuity for 2.44 normalised lines. The visual motor factor is involved in amblyopia treatment.

The seam visual tracking method for large structures

NASA Astrophysics Data System (ADS)

Bi, Qilin; Jiang, Xiaomin; Liu, Xiaoguang; Cheng, Taobo; Zhu, Yulong

2017-10-01

In this paper, a compact and flexible weld visual tracking method is proposed. Firstly, there was the interference between the visual device and the work-piece to be welded when visual tracking height cannot change. a kind of weld vision system with compact structure and tracking height is researched. Secondly, according to analyze the relative spatial pose between the camera, the laser and the work-piece to be welded and study with the theory of relative geometric imaging, The mathematical model between image feature parameters and three-dimensional trajectory of the assembly gap to be welded is established. Thirdly, the visual imaging parameters of line structured light are optimized by experiment of the weld structure of the weld. Fourth, the interference that line structure light will be scatters at the bright area of metal and the area of surface scratches will be bright is exited in the imaging. These disturbances seriously affect the computational efficiency. The algorithm based on the human eye visual attention mechanism is used to extract the weld characteristics efficiently and stably. Finally, in the experiment, It is verified that the compact and flexible weld tracking method has the tracking accuracy of 0.5mm in the tracking of large structural parts. It is a wide range of industrial application prospects.

Sketchy Rendering for Information Visualization.

PubMed

Wood, J; Isenberg, P; Isenberg, T; Dykes, J; Boukhelifa, N; Slingsby, A

2012-12-01

We present and evaluate a framework for constructing sketchy style information visualizations that mimic data graphics drawn by hand. We provide an alternative renderer for the Processing graphics environment that redefines core drawing primitives including line, polygon and ellipse rendering. These primitives allow higher-level graphical features such as bar charts, line charts, treemaps and node-link diagrams to be drawn in a sketchy style with a specified degree of sketchiness. The framework is designed to be easily integrated into existing visualization implementations with minimal programming modification or design effort. We show examples of use for statistical graphics, conveying spatial imprecision and for enhancing aesthetic and narrative qualities of visualization. We evaluate user perception of sketchiness of areal features through a series of stimulus-response tests in order to assess users' ability to place sketchiness on a ratio scale, and to estimate area. Results suggest relative area judgment is compromised by sketchy rendering and that its influence is dependent on the shape being rendered. They show that degree of sketchiness may be judged on an ordinal scale but that its judgement varies strongly between individuals. We evaluate higher-level impacts of sketchiness through user testing of scenarios that encourage user engagement with data visualization and willingness to critique visualization design. Results suggest that where a visualization is clearly sketchy, engagement may be increased and that attitudes to participating in visualization annotation are more positive. The results of our work have implications for effective information visualization design that go beyond the traditional role of sketching as a tool for prototyping or its use for an indication of general uncertainty.

The Eye Phone Study: reliability and accuracy of assessing Snellen visual acuity using smartphone technology

PubMed Central

Perera, C; Chakrabarti, R; Islam, F M A; Crowston, J

2015-01-01

Purpose Smartphone-based Snellen visual acuity charts has become popularized; however, their accuracy has not been established. This study aimed to evaluate the equivalence of a smartphone-based visual acuity chart with a standard 6-m Snellen visual acuity (6SVA) chart. Methods First, a review of available Snellen chart applications on iPhone was performed to determine the most accurate application based on optotype size. Subsequently, a prospective comparative study was performed by measuring conventional 6SVA and then iPhone visual acuity using the ‘Snellen' application on an Apple iPhone 4. Results Eleven applications were identified, with accuracy of optotype size ranging from 4.4–39.9%. Eighty-eight patients from general medical and surgical wards in a tertiary hospital took part in the second part of the study. The mean difference in logMAR visual acuity between the two charts was 0.02 logMAR (95% limit of agreement −0.332, 0.372 logMAR). The largest mean difference in logMAR acuity was noted in the subgroup of patients with 6SVA worse than 6/18 (n=5), who had a mean difference of two Snellen visual acuity lines between the charts (0.276 logMAR). Conclusion We did not identify a Snellen visual acuity app at the time of study, which could predict a patients standard Snellen visual acuity within one line. There was considerable variability in the optotype accuracy of apps. Further validation is required for assessment of acuity in patients with severe vision impairment. PMID:25931170

Long-term spectroscopic monitoring of the Luminous Blue Variable AG Carinae

NASA Astrophysics Data System (ADS)

Stahl, O.; Jankovics, I.; Kovács, J.; Wolf, B.; Schmutz, W.; Kaufer, A.; Rivinius, Th.; Szeifert, Th.

2001-08-01

We have extensively monitored the Luminous Blue Variable AG Car (HD 94910) spectroscopically. Our data cover the years 1989 to 1999. In this period, the star underwent almost a full S Dor cycle from visual minimum to maximum and back. Over several seasons, up to four months of almost daily spectra are available. Our data cover most of the visual spectral range with a high spectral resolution (lambda /Delta lambda ~ 20 000). This allows us to investigate the variability in many lines on time scales from days to years. The strongest variability occurs on a time scale of years. Qualitatively, the variations can be understood as changes of the effective temperature and radius, which are in phase with the optical light curve. Quantitatively, there are several interesting deviations from this behaviour, however. The Balmer lines show P Cygni profiles and have their maximum strength (both in equivalent width and line flux) after the peak of the optical light curve, at the descending branch of the light curve. The line-width during maximum phase is smaller than during minimum, but it has a local maximum close to the peak of the visual light curve. We derive mass-loss rates over the cycle from the Hα line and find the highest mass loss rates (log dot {M}/({M}_sun yr-1) ~ -3.8, about a factor of five higher than in the minimum, where we find log dot {M}/({M}_sun yr-1) ~ -4.5) after the visual maximum. Line-splitting is very commonly observed, especially on the rise to maximum and on the descending branch from maximum. The components are very long-lived (years) and are probably unrelated to similar-looking line-splitting events in normal supergiants. Small apparent accelerations of the components are observed. The change in radial velocity could be due to successive narrowing of the components, with the absorption disappearing at small expansion velocities first. In general, the line-splitting is more likely the result of missing absorption at intermediate velocities than of excess absorption at the velocities of the components. The HeI lines and other lines which form deep in the atmosphere show the most peculiar variations. The HeI lines show a central absorption with variable blue- and red-shifted emission components. Due to the variations of the emission components, the HeI lines can change their line profile from a normal P Cyg profile to an inverse P Cyg-profile or double-peak emission. In addition, very broad (+/-1500 km s-1) emission wings are seen at the strongest HeI lines of AG Car. At some phases, a blue-shifted absorption is also present. The central absorption of the HeI lines is blue-shifted before and red-shifted after maximum. Possibly, we directly see the expansion and contraction of the photosphere. If this explanation is correct, the velocity of the continuum-forming layer is not dominated by expansion but is only slightly oscillating around the systemic velocity. Based on observations collected at the European Southern Observatory at La Silla, Chile.

Calibrating Reach Distance to Visual Targets

ERIC Educational Resources Information Center

Mon-Williams, Mark; Bingham, Geoffrey P.

2007-01-01

The authors investigated the calibration of reach distance by gradually distorting the haptic feedback obtained when participants grasped visible target objects. The authors found that the modified relationship between visually specified distance and reach distance could be captured by a straight-line mapping function. Thus, the relation could be…

Visual Research Methods: Image, Society, and Representation

ERIC Educational Resources Information Center

Stanczak, Gregory C., Ed.

2007-01-01

Visual research is reemerging across the social sciences as a significant, underutilized resource producing unique lines of inquiry and sparking innovative pedagogies. Stanczak's edited volume crisscrosses disciplines in ways that highlights the multiple manifestations of this newer interdisciplinary trend. As such, this volume will be useful as…

Visualizing Vector Fields Using Line Integral Convolution and Dye Advection

NASA Technical Reports Server (NTRS)

Shen, Han-Wei; Johnson, Christopher R.; Ma, Kwan-Liu

1996-01-01

We present local and global techniques to visualize three-dimensional vector field data. Using the Line Integral Convolution (LIC) method to image the global vector field, our new algorithm allows the user to introduce colored 'dye' into the vector field to highlight local flow features. A fast algorithm is proposed that quickly recomputes the dyed LIC images. In addition, we introduce volume rendering methods that can map the LIC texture on any contour surface and/or translucent region defined by additional scalar quantities, and can follow the advection of colored dye throughout the volume.

In-line agglomeration degree estimation in fluidized bed pellet coating processes using visual imaging.

PubMed

Mehle, Andraž; Kitak, Domen; Podrekar, Gregor; Likar, Boštjan; Tomaževič, Dejan

2018-05-09

Agglomeration of pellets in fluidized bed coating processes is an undesirable phenomenon that affects the yield and quality of the product. In scope of PAT guidance, we present a system that utilizes visual imaging for in-line monitoring of the agglomeration degree. Seven pilot-scale Wurster coating processes were executed under various process conditions, providing a wide spectrum of process outcomes. Images of pellets were acquired during the coating processes in a contactless manner through an observation window of the coating apparatus. Efficient image analysis methods were developed for automatic recognition of discrete pellets and agglomerates in the acquired images. In-line obtained agglomeration degree trends revealed the agglomeration dynamics in distinct phases of the coating processes. We compared the in-line estimated agglomeration degree in the end point of each process to the results obtained by the off-line sieve analysis reference method. A strong positive correlation was obtained (coefficient of determination R 2 =0.99), confirming the feasibility of the approach. The in-line estimated agglomeration degree enables early detection of agglomeration and provides means for timely interventions to retain it in an acceptable range. Copyright © 2018 Elsevier B.V. All rights reserved.

Two wrongs make a right: linear increase of accuracy of visually-guided manual pointing, reaching, and height-matching with increase in hand-to-body distance.

PubMed

Li, Wenxun; Matin, Leonard

2005-03-01

Measurements were made of the accuracy of open-loop manual pointing and height-matching to a visual target whose elevation was perceptually mislocalized. Accuracy increased linearly with distance of the hand from the body, approaching complete accuracy at full extension; with the hand close to the body (within the midfrontal plane), the manual errors equaled the magnitude of the perceptual mislocalization. The visual inducing stimulus responsible for the perceptual errors was a single pitched-from-vertical line that was long (50 degrees), eccentrically-located (25 degrees horizontal), and viewed in otherwise total darkness. The line induced perceptual errors in the elevation of a small, circular visual target set to appear at eye level (VPEL), a setting that changed linearly with the change in the line's visual pitch as has been previously reported (pitch: -30 degrees topbackward to 30 degrees topforward); the elevation errors measured by VPEL settings varied systematically with pitch through an 18 degrees range. In a fourth experiment the visual inducing stimulus responsible for the perceptual errors was shown to induce separately-measured errors in the manual setting of the arm to feel horizontal that were also distance-dependent. The distance-dependence of the visually-induced changes in felt arm position accounts quantitatively for the distance-dependence of the manual errors in pointing/reaching and height matching to the visual target: The near equality of the changes in felt horizontal and changes in pointing/reaching with the finger at the end of the fully extended arm is responsible for the manual accuracy of the fully-extended point; with the finger in the midfrontal plane their large difference is responsible for the inaccuracies of the midfrontal-plane point. The results are inconsistent with the widely-held but controversial theory that visual spatial information employed for perception and action are dissociated and different with no illusory visual influence on action. A different two-system theory, the Proximal/Distal model, employing the same signals from vision and from the body-referenced mechanism with different weights for different hand-to-body distances, accounts for both the perceptual and the manual results in the present experiments.

Enhanced line integral convolution with flow feature detection

DOT National Transportation Integrated Search

1995-01-01

Prepared ca. 1995. The Line Integral Convolution (LIC) method, which blurs white noise textures along a vector field, is an effective way to visualize overall flow patterns in a 2D domain [Cabral & Leedom '93]. The method produces a flow texture imag...

Impact of low vision rehabilitation on functional vision performance of children with visual impairment.

PubMed

Ganesh, Suma; Sethi, Sumita; Srivastav, Sonia; Chaudhary, Amrita; Arora, Priyanka

2013-09-01

To evaluate the impact of low vision rehabilitation on functional vision of children with visual impairment. The LV Prasad-Functional Vision Questionnaire, designed specifically to measure functional performance of visually impaired children of developing countries, was used to assess the level of difficulty in performing various tasks pre and post visual rehabilitation in children with documented visual impairment. Chi-square test was used to assess the impact of rehabilitation intervention on functional vision performance; a P < 0.05 was considered significant. LogMAR visual acuity prior to the introduction of low vision devices (LVDs) was 0.90 ± 0.05 for distance and for near it was 0.61 ± 0.05. After the intervention, the acuities improved significantly for distance (0.2 ± 0.27; P < 0.0001) and near (0.42 ± 0.17; P = 0.001). The most common reported difficulties were related to their academic activities like copying from the blackboard (80%), reading textbook at arm's length (77.2%), and writing along a straight line (77.2%). Absolute raw score of disability pre-LVD was 15.05 which improved to 7.58 post-LVD. An improvement in functional vision post visual rehabilitation was especially found in those activities related to their studying lifestyle like copying from the blackboard (P < 0.0001), reading textbook at arm's length (P < 0.0001), and writing along a straight line (P = 0.003). In our study group, there was a significant improvement in functional vision post visual rehabilitation, especially with those activities which are related to their academic output. It is important for these children to have an early visual rehabilitation to decrease the impairment associated with these decreased visual output and to enhance their learning abilities.

Possible role for fundus autofluorescence as a predictive factor for visual acuity recovery after epiretinal membrane surgery.

PubMed

Brito, Pedro N; Gomes, Nuno L; Vieira, Marco P; Faria, Pedro A; Fernandes, Augusto V; Rocha-Sousa, Amândio; Falcão-Reis, Fernando

2014-02-01

To study the potential association between fundus autofluorescence, spectral-domain optical coherence tomography, and visual acuity in patients undergoing surgery because of epiretinal membranes. Prospective, interventional case series including 26 patients submitted to vitrectomy because of symptomatic epiretinal membranes. Preoperative evaluation consisted of a complete ophthalmologic examination, autofluorescence, and spectral-domain optical coherence tomography. Studied variables included foveal autofluorescence (fov.AF), photoreceptor inner segment/outer segment (IS/OS) junction line integrity, external limiting membrane integrity, central foveal thickness, and foveal morphology. All examinations were repeated at the first, third, and sixth postoperative months. The main outcome measures were logarithm of minimal angle resolution visual acuity, fov.AF integrity, and IS/OS integrity. All cases showing a continuous IS/OS line had an intact fov.AF, whereas patients with IS/OS disruption could have either an increased area of foveal hypoautofluorescence or an intact fov.AF, with the latter being associated with IS/OS integrity recovery in follow-up spectral-domain optical coherence tomography imaging. The only preoperative variables presenting a significant correlation with final visual acuity were baseline visual acuity (P = 0.047) and fov.AF grade (P = 0.023). Recovery of IS/OS line integrity after surgery, in patients with preoperative IS/OS disruption and normal fov.AF, can be explained by the presence of a functional retinal pigment epithelium-photoreceptor complex, supporting normal photoreceptor activity. Autofluorescence imaging provides a functional component to the study of epiretinal membranes, complementing the structural information obtained with optical coherence tomography.

Opposite Effects of Visual Cueing During Writing-Like Movements of Different Amplitudes in Parkinson's Disease.

PubMed

Nackaerts, Evelien; Nieuwboer, Alice; Broeder, Sanne; Smits-Engelsman, Bouwien C M; Swinnen, Stephan P; Vandenberghe, Wim; Heremans, Elke

2016-06-01

Handwriting is often impaired in Parkinson's disease (PD). Several studies have shown that writing in PD benefits from the use of cues. However, this was typically studied with writing and drawing sizes that are usually not used in daily life. This study examines the effect of visual cueing on a prewriting task at small amplitudes (≤1.0 cm) in PD patients and healthy controls to better understand the working action of cueing for writing. A total of 15 PD patients and 15 healthy, age-matched controls performed a prewriting task at 0.6 cm and 1.0 cm in the presence and absence of visual cues (target lines). Writing amplitude, variability of amplitude, and speed were chosen as dependent variables, measured using a newly developed touch-sensitive tablet. Cueing led to immediate improvements in writing size, variability of writing size, and speed in both groups in the 1.0 cm condition. However, when writing at 0.6 cm with cues, a decrease in writing size was apparent in both groups (P < .001) and the difference in variability of amplitude between cued and uncued writing disappeared. In addition, the writing speed of controls decreased when the cue was present. Visual target lines of 1.0 cm improved the writing of sequential loops in contrast to lines spaced at 0.6 cm. These results illustrate that, unlike for gait, visual cueing for fine-motor tasks requires a differentiated approach, taking into account the possible increases of accuracy constraints imposed by cueing. © The Author(s) 2015.

Dyscalculia and the Calculating Brain.

PubMed

Rapin, Isabelle

2016-08-01

Dyscalculia, like dyslexia, affects some 5% of school-age children but has received much less investigative attention. In two thirds of affected children, dyscalculia is associated with another developmental disorder like dyslexia, attention-deficit disorder, anxiety disorder, visual and spatial disorder, or cultural deprivation. Infants, primates, some birds, and other animals are born with the innate ability, called subitizing, to tell at a glance whether small sets of scattered dots or other items differ by one or more item. This nonverbal approximate number system extends mostly to single digit sets as visual discrimination drops logarithmically to "many" with increasing numerosity (size effect) and crowding (distance effect). Preschoolers need several years and specific teaching to learn verbal names and visual symbols for numbers and school agers to understand their cardinality and ordinality and the invariance of their sequence (arithmetic number line) that enables calculation. This arithmetic linear line differs drastically from the nonlinear approximate number system mental number line that parallels the individual number-tuned neurons in the intraparietal sulcus in monkeys and overlying scalp distribution of discrete functional magnetic resonance imaging activations by number tasks in man. Calculation is a complex skill that activates both visual and spatial and visual and verbal networks. It is less strongly left lateralized than language, with approximate number system activation somewhat more right sided and exact number and arithmetic activation more left sided. Maturation and increasing number skill decrease associated widespread non-numerical brain activations that persist in some individuals with dyscalculia, which has no single, universal neurological cause or underlying mechanism in all affected individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

Visual and ocular changes associated with exposure to two tertiary amines

PubMed Central

Page, E; Cook, C; Hater, M; Mueller, C; Grote, A; Mortimer, V

2003-01-01

Aims: To determine if exposure to dimethylisopropanolamine (DMIPA) and dimethylaminoethanol (DMAE) in a label printing plant was associated with visual disturbances and/or ocular changes. Methods: Questionnaires, eye examinations (visual acuity, contrast sensitivity at 2.5% and 1.25% contrast, slit lamp biomicroscopy, and pachymetry), and industrial hygiene monitoring for DMIPA and DMAE were performed over a two week period. Results: Eighty nine per cent of line workers reported having experienced blurry vision while at work in the past 12 months, compared to 12.5% of prime workers. A total of 108 full shift personal breathing zone (PBZ) air samples for the amines were collected. The mean time weighted average (TWA) concentration of DMIPA was significantly higher in the line division than in the prime division, as was the mean TWA concentration for total amines. The mean TWA concentration of DMAE was higher in the prime division than the line division. Higher levels of total amines were associated with increased risk of reporting blurry vision, halo vision, and blue-grey vision. The risk of corneal opacity rose with increasing exposure to total amines. The prevalence of corneal opacity also increased with increasing concentration of total amines. Median corneal thickness increased with increasing grades of corneal opacity. There was a statistically significant relation between total amine concentration and increased risk of reduced bilateral visual acuity and 2.5% contrast sensitivity. Conclusions: Exposure to tertiary amines was associated with blurry, halo, and blue-grey vision, corneal opacity, and decrements in visual acuity and contrast sensitivity at 2.5% contrast. PMID:12499461

Atropine vs patching for treatment of moderate amblyopia: follow-up at 15 years of age of a randomized clinical trial.

PubMed

Repka, Michael X; Kraker, Raymond T; Holmes, Jonathan M; Summers, Allison I; Glaser, Stephen R; Barnhardt, Carmen N; Tien, David R

2014-07-01

Initial treatment for amblyopia of the fellow eye with patching and atropine sulfate eyedrops improves visual acuity. Long-term data on the durability of treatment benefit are needed. To report visual acuity at 15 years of age among patients who were younger than 7 years when enrolled in a treatment trial for moderate amblyopia. In a multicenter clinical trial, 419 children with amblyopia (visual acuity, 20/40 to 20/100) were randomly assigned to patching (minimum of 6 h/d) or atropine sulfate eyedrops, 1% (1 drop daily), for 6 months. Treatment after 6 months was at the discretion of the investigator. Two years after enrollment, an unselected subgroup of 188 children were enrolled into long-term follow-up. Initial treatment with patching or atropine with subsequent treatment at investigator discretion. Visual acuity at 15 years of age with the electronic Early Treatment Diabetic Retinopathy Study test in amblyopic and fellow eyes. Mean visual acuity in the amblyopic eye measured in 147 participants at 15 years of age was 0.14 logMAR (approximately 20/25); 59.9% of amblyopic eyes had visual acuity of 20/25 or better and 33.3%, 20/20 or better. Mean interocular acuity difference (IOD) at 15 years of age was 0.21 logMAR (2.1 lines); 48.3% had an IOD of 2 or more lines and 71.4%, 1 or more lines. Treatment (other than spectacles) was prescribed for 9 participants (6.1%) aged 10 to 15 years. Mean IOD was similar at examinations at 10 and 15 years of age (2.0 and 2.1 logMAR lines, respectively; P = .39). Better visual acuity at the 15-year examination was achieved in those who were younger than 5 years at the time of entry into the randomized clinical trial (mean logMAR, 0.09) compared with those aged 5 to 6 years (mean logMAR, 0.18; P < .001). When we compared subgroups based on original treatment with atropine or patching, no significant differences were observed in visual acuity of amblyopic and fellow eyes at 15 years of age (P = .44 and P = .43, respectively). At 15 years of age, most children treated for moderate amblyopia when younger than 7 years have good visual acuity, although mild residual amblyopia is common. The outcome is similar regardless of initial treatment with atropine or patching. The results indicate that improvement occurring with amblyopia treatment is maintained until at least 15 years of age. clinicaltrials.gov Identifier: NCT00000170.

Visual processing in Alzheimer's disease: surface detail and colour fail to aid object identification.

PubMed

Adlington, Rebecca L; Laws, Keith R; Gale, Tim M

2009-10-01

It has been suggested that object recognition in patients with Alzheimer's disease (AD) may be strongly influenced both by image format (e.g. colour vs. line-drawn) and by low-level visual impairments. To examine these notions, we tested basic visual functioning and picture naming in 41 AD patients and 40 healthy elderly controls. Picture naming was examined using 105 images representing a wide range of living and nonliving subcategories (from the Hatfield image test [HIT]: [Adlington, R. A., Laws, K. R., & Gale, T. M. (in press). The Hatfield image test (HIT): A new picture test and norms for experimental and clinical use. Journal of Clinical and Experimental Neuropsychology]), with each item presented in colour, greyscale, or line-drawn formats. Whilst naming for elderly controls improved linearly with the addition of surface detail and colour, AD patients showed no benefit from the addition of either surface information or colour. Additionally, controls showed a significant category by format interaction; however, the same profile did not emerge for AD patients. Finally, AD patients showed widespread and significant impairment on tasks of visual functioning, and low-level visual impairment was predictive of patient naming.

Maxillary anterior papilla display during smiling: a clinical study of the interdental smile line.

PubMed

Hochman, Mark N; Chu, Stephen J; Tarnow, Dennis P

2012-08-01

The purpose of this research was to quantify the visual display (presence) or lack of display (absence) of interdental papillae during maximum smiling in a patient population aged 10 to 89 years. Four hundred twenty digital single-lens reflex photographs of patients were taken and examined for the visual display of interdental papillae between the maxillary anterior teeth during maximum smiling. Three digital photographs were taken per patient from the frontal, right frontal-lateral, and left frontal-lateral views. The data set of photographs was examined by two examiners for the presence or absence of the visual display of papillae. The visual display of interdental papillae during maximum smiling occurred in 380 of the 420 patients examined in this study, equivalent to a 91% occurrence rate. Eighty-seven percent of all patients categorized as having a low gingival smile line (n = 303) were found to display the interdental papillae upon smiling. Differences were noted for individual age groups according to the decade of life as well as a trend toward decreasing papillary display with increasing age. The importance of interdental papillae display during dynamic smiling should not be left undiagnosed since it is visible in over 91% of older patients and in 87% of patients with a low gingival smile line, representing a common and important esthetic element that needs to be assessed during smile analysis of the patient.

The interaction between the cognitive style of field dependence and visual presentations in color, monochrome, and line drawings

NASA Astrophysics Data System (ADS)

Myers, Robert Gardner

1997-12-01

The purpose of this study was to determine whether there is a correlation between the cognitive style of field dependence and the type of visual presentation format used in a computer-based tutorial (color; black and white: or line drawings) when subjects are asked to identify human tissue samples. Two hundred-four college students enrolled in human anatomy and physiology classes at Westmoreland County Community College participated. They were first administered the Group Embedded Figures Test (GEFT) and then were divided into three groups: field-independent (score, 15-18), field-neutral (score, 11-14), and field dependent (score, 0-10). Subjects were randomly assigned to one of the three treatment groups. Instruction was delivered by means of a computer-aided tutorial consisting of text and visuals of human tissue samples. The pretest and posttest consisted of 15 tissue samples, five from each treatment, that were imported into the HyperCardsp{TM} stack and were played using QuickTimesp{TM} movie extensions. A two-way analysis of covariance (ANCOVA) using pretest and posttest scores was used to investigate whether there is a relationship between field dependence and each of the three visual presentation formats. No significant interaction was found between individual subject's relative degree of field dependence and any of the different visual presentation formats used in the computer-aided tutorial module, F(4,194) = 1.78, p =.1335. There was a significant difference between the students' levels of field dependence in terms of their ability to identify human tissue samples, F(2,194) = 5.83, p =.0035. Field-independent subjects scored significantly higher (M = 10.59) on the posttest than subjects who were field-dependent (M = 9.04). There was also a significant difference among the various visual presentation formats, F(2,194) = 3.78, p =.0245. Subjects assigned to the group that received the color visual presentation format scored significantly higher (M = 10.38) on the posttest measure than did those assigned to the group that received the line drawing visual presentation format (8.99).

Investigating Navy Officer Retention Using Data Farming

DTIC Science & Technology

2015-09-01

runs on Microsoft Access . Contractors from SAG Corporation translated the code into Visual Basic for Applications ( VBA ), bringing several benefits...18  b.  Accessions ............................................................. 18  c.  Promotions...Strategic Actions Group SEED Simulation Experiments & Efficient Design URL Unrestricted Line VBA Visual Basic for Applications VV&A Verification

Multiple Learning Strategies Project. Small Engine Repair. Visually Impaired.

ERIC Educational Resources Information Center

Foster, Don; And Others

This instructional package designed for visually impaired students, focuses on the vocational area of small engine repair. Contained in this document are forty learning modules organized into fourteen units: engine block; starters; fuel tank, lines, filters and pumps; carburetors; electrical; test equipment; motorcycle; machining; tune-ups; short…

40 CFR 63.7740 - What are my monitoring requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) National Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Continuous...) Inspect fans for wear, material buildup, and corrosion through quarterly visual inspections, vibration... more automated conveyor and pallet cooling lines and automated shakeout lines at a new iron and steel...

A Computerized System for Measuring Detection Sensitivity over the Visual Field,

DTIC Science & Technology

1986-06-01

variety of conditions can act to degrade this basic configuration of detection capability; e.g., pathology, such as glaucoma and retinitis pigmentosa ...the central line of sight involving the retinal fovea is clearly the locus of greatest visual resolution under photopic viewing conditions, the...Skills. 1974; 41:467-474. 6. Kobrick JL, Appleton S. Effects of hypoxia on visual performance and retinal vascular state. J. Appl. Physiol. 1971; 31:357

Conventional occlusion versus pharmacologic penalization for amblyopia.

PubMed

Li, Tianjing; Shotton, Kate

2009-10-07

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses. To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia. We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009. We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia. Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias. Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and atropine penalization was found. Although both treatments were well tolerated, compliance was better in atropine. Atropine penalization costs less than conventional occlusion. The results indicate that atropine penalization is as effective as conventional occlusion. Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the three trials. Atropine penalization can be used as first line treatment for amblyopia.

Esthetics and smile-related characteristics assessed by laypersons.

PubMed

Wang, Cui; Hu, Wen-Jie; Liang, Ling-Zhi; Zhang, Yan-Ling; Chung, Kwok-Hung

2018-03-01

This study aimed to identify the characteristics of full-smile images assessed by laypersons using visual analog scale measurement. A total of 176 young Chinese subjects (88 males and 88 females; 20-35 years of age) with healthy dentogingival tissue were recruited to have their dynamic smiles captured using digital technology. A full-smile frame image of each subject was selected and evaluated by 22 laypersons (11 males and 11 females; 20-35 years of age) using visual analog scale measurement. Unattractive and attractive groups were designated according to the 25th percentile and 75th percentile of average visual analog scale score for the subjects, respectively. Eight smile variables were used to measure the characteristics of the full-smile images. Pearson's Chi-square test and unpaired t tests were used to analyze the data with significance level α = 0.05. The visual analog scale measurement scores of unattractive and attractive subgroups, respectively, were 37.89 ± 2.12 and 50.67 ± 2.75 (male subjects), and 37.14 ± 2.80 and 51.92 ± 1.99 (female subjects). VAS scores were significantly different between subgroups for both male and female subjects (P < .001). No significant differences were observed between male and female subjects (P > .05). Attractive full-smiles in young Chinese subjects demonstrated higher frequencies of average or low anterior smile line, average or low posterior smile line, upward upper lip curvature, and "broad and short" smile with high smile index. The smile variables of anterior smile line, posterior smile line, upper lip curvature, and smile index are predominant factors of smile attractiveness, which should be given priority to consider and manage in the anterior esthetic treatment plan. © 2017 Wiley Periodicals, Inc.

Mild decentration measured by a Scheimpflug camera and its impact on visual quality following SMILE in the early learning curve.

PubMed

Li, Meiyan; Zhao, Jing; Miao, Huamao; Shen, Yang; Sun, Ling; Tian, Mi; Wadium, Elizabeth; Zhou, Xingtao

2014-05-20

To measure decentration following femtosecond laser small incision lenticule extraction (SMILE) for the correction of myopia and myopic astigmatism in the early learning curve, and to investigate its impact on visual quality. A total of 55 consecutive patients (100 eyes) who underwent the SMILE procedure were included. Decentration was measured using a Scheimpflug camera 6 months after surgery. Uncorrected and corrected distance visual acuity (UDVA, CDVA), manifest refraction, and wavefront errors were also measured. Associations between decentration and the preoperative spherical equivalent were analyzed, as well as the associations between decentration and wavefront aberrations. Regarding efficacy and safety, 40 eyes (40%) had an unchanged CDVA; 32 eyes (32%) gained one line; and 11 eyes (11%) gained two lines. Fifteen eyes (15%) lost one line of CDVA, and two eyes (2%) lost two lines. Ninety-nine of the treated eyes (99%) had a postoperative UDVA better than 1.0, and 100 eyes (100%) had a UDVA better than 0.8. The mean decentered displacement was 0.17 ± 0.09 mm. The decentered displacement of all treated eyes (100%) was within 0.50 mm; 70 eyes (70%) were within 0.20 mm; and 90 eyes (90%) were within 0.30 mm. The vertical coma showed the greatest increase in magnitude. The magnitude of horizontal decentration was found to be associated with an induced horizontal coma. This study suggests that, although mild decentration occurred in the early learning curve, good visual outcomes were achieved after the SMILE surgery. Special efforts to minimize induced vertical coma are necessary. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Line-oriented flight training

NASA Technical Reports Server (NTRS)

Beach, B. E.

1980-01-01

Some of the concepts related to a line-oriented flight training program are discussed. The need to shift from training in manipulative skills to something closer to management skills is emphasized. The program is evaluated in terms of its realistic approaches which include the simulator's optimized motion and visual capabilities. The value of standard operating procedures as they affect the line pilot in everyday operations are also illustrated.

Study and response time for the visual recognition of 'similarity' and identity

NASA Technical Reports Server (NTRS)

Derks, P. L.; Bauer, T. M.

1974-01-01

Four subjects compared successively presented pairs of line patterns for a match between any lines in the pattern (similarity) and for a match between all lines (identity). The encoding or study times for pattern recognition from immediate memory and the latency in responses to comparison stimuli were examined. Qualitative differences within and between subjects were most evident in study times.

Colorado as seen from STS-58

NASA Image and Video Library

1993-10-30

STS058-89-013 (18 Oct-1 Nov 1993) --- An oblique westward view, across the wheat fields and cattle pastures, of eastern Colorado to the Front Range of the Rocky Mountains. Denver is bisected at the center of the right edge of the frame. Pikes Peak and Colorado Springs are left of center, and the Arkansas River Valley with Canyon City and the Royal Gorge are along the left edge of the frame. This view shows the startling contrast between the nearly-flat High Plains and the ancient geological uplift of the Rockies.

Using an artificial neural network to classify multicomponent emission lines with integral field spectroscopy from SAMI and S7

NASA Astrophysics Data System (ADS)

Hampton, E. J.; Medling, A. M.; Groves, B.; Kewley, L.; Dopita, M.; Davies, R.; Ho, I.-T.; Kaasinen, M.; Leslie, S.; Sharp, R.; Sweet, S. M.; Thomas, A. D.; Allen, J.; Bland-Hawthorn, J.; Brough, S.; Bryant, J. J.; Croom, S.; Goodwin, M.; Green, A.; Konstantantopoulos, I. S.; Lawrence, J.; López-Sánchez, Á. R.; Lorente, N. P. F.; McElroy, R.; Owers, M. S.; Richards, S. N.; Shastri, P.

2017-09-01

Integral field spectroscopy (IFS) surveys are changing how we study galaxies and are creating vastly more spectroscopic data available than before. The large number of resulting spectra makes visual inspection of emission line fits an infeasible option. Here, we present a demonstration of an artificial neural network (ANN) that determines the number of Gaussian components needed to describe the complex emission line velocity structures observed in galaxies after being fit with lzifu. We apply our ANN to IFS data for the S7 survey, conducted using the Wide Field Spectrograph on the ANU 2.3 m Telescope, and the SAMI Galaxy Survey, conducted using the SAMI instrument on the 4 m Anglo-Australian Telescope. We use the spectral fitting code lzifu (Ho et al. 2016a) to fit the emission line spectra of individual spaxels from S7 and SAMI data cubes with 1-, 2- and 3-Gaussian components. We demonstrate that using an ANN is comparable to astronomers performing the same visual inspection task of determining the best number of Gaussian components to describe the physical processes in galaxies. The advantage of our ANN is that it is capable of processing the spectra for thousands of galaxies in minutes, as compared to the years this task would take individual astronomers to complete by visual inspection.

Impact of visual acuity on developing literacy at age 4-5 years: a cohort-nested cross-sectional study.

PubMed

Bruce, Alison; Fairley, Lesley; Chambers, Bette; Wright, John; Sheldon, Trevor A

2016-02-16

To estimate the prevalence of poor vision in children aged 4-5 years and determine the impact of visual acuity on literacy. Cross-sectional study linking clinical, epidemiological and education data. Schools located in the city of Bradford, UK. Prevalence was determined for 11,186 children participating in the Bradford school vision screening programme. Data linkage was undertaken for 5836 Born in Bradford (BiB) birth cohort study children participating both in the Bradford vision screening programme and the BiB Starting Schools Programme. 2025 children had complete data and were included in the multivariable analyses. Visual acuity was measured using a logMAR Crowded Test (higher scores=poorer visual acuity). Literacy measured by Woodcock Reading Mastery Tests-Revised (WRMT-R) subtest: letter identification (standardised). The mean (SD) presenting visual acuity was 0.14 (0.09) logMAR (range 0.0-1.0). 9% of children had a presenting visual acuity worse than 0.2logMAR (failed vision screening), 4% worse than 0.3logMAR (poor visual acuity) and 2% worse than 0.4logMAR (visually impaired). Unadjusted analysis showed that the literacy score was associated with presenting visual acuity, reducing by 2.4 points for every 1 line (0.10logMAR) reduction in vision (95% CI -3.0 to -1.9). The association of presenting visual acuity with the literacy score remained significant after adjustment for demographic and socioeconomic factors reducing by 1.7 points (95% CI -2.2 to -1.1) for every 1 line reduction in vision. Prevalence of decreased visual acuity was high compared with other population-based studies. Decreased visual acuity at school entry is associated with reduced literacy. This may have important implications for the children's future educational, health and social outcomes. 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/

Common angle plots as perception-true visualizations of categorical associations.

PubMed

Hofmann, Heike; Vendettuoli, Marie

2013-12-01

Visualizations are great tools of communications-they summarize findings and quickly convey main messages to our audience. As designers of charts we have to make sure that information is shown with a minimum of distortion. We have to also consider illusions and other perceptual limitations of our audience. In this paper we discuss the effect and strength of the line width illusion, a Muller-Lyer type illusion, on designs related to displaying associations between categorical variables. Parallel sets and hammock plots are both affected by line width illusions. We introduce the common-angle plot as an alternative method for displaying categorical data in a manner that minimizes the effect from perceptual illusions. Results from user studies both highlight the need for addressing line-width illusions in displays and provide evidence that common angle charts successfully resolve this issue.

A rapid quantification of binocular misalignment without recording eye movements: Vertical and torsional alignment nulling.

PubMed

Beaton, Kara H; Shelhamer, Mark J; Roberts, Dale C; Schubert, Michael C

2017-05-01

Small, innate asymmetries between the left and right otolith organs can cause ocular misalignment with symptoms that include double vision and motion sickness. Additionally, ocular misalignment affects nearly 5% of the US population. We have developed a portable, non-invasive technology that uses subjective perception of binocular visual signals to estimate relative binocular alignment. The Vertical Alignment Nulling (VAN) and Torsional Alignment Nulling (TAN) tests ask subjects to view one red and one blue line on a tablet computer while looking through color-matched red and blue filters so that each eye sees only one of the lines. Subjects align the red and blue lines, which are initially vertically offset from one another during VAN or rotated relative to one another during TAN, until they perceive a single continuous line. Ocular misalignments are inferred from actual offsets in the final line positions. During testing, all binocular visual cues are eliminated by employing active-matrix organic light-emitting diode (AMOLED) technology and testing in darkness. VAN and TAN can accurately account for visual offsets induced by prisms, and test-retest reliability is excellent, with resolution better than many current standard clinical tests. VAN and TAN tests are similar to the clinical Lancaster red-green test. However, VAN and TAN employ inexpensive, hand-held hardware that can be self-administered with results that are quickly quantifiable. VAN and TAN provide simple, sensitive, and quantitative measures of binocular positioning alignment that may be useful for detecting subtle abnormalities in ocular positioning. Copyright © 2017 Elsevier B.V. All rights reserved.

Simple spectroscope used with solid state image amplifier over wide spectral range

NASA Technical Reports Server (NTRS)

Brown, R. L., Sr.

1971-01-01

Prism plus image amplifier panel provides visual image of many infrared spectral lines from carbon arc impregnated with metal compound. Different metal compounds generate various desired spectra. Panel also aligns and focuses simple spectroscopes for detecting spectral lines inside and outside visible region.