2,252 research outputs found

    A proposed method for on-board monitoring of discrete signals

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    On-board monitor of discrete signals of space vehicl

    Visual mental imagery during caloric vestibular stimulation.

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    We investigated high-resolution mental imagery and mental rotation, while the participants received caloric vestibular stimulation. High-resolution visual mental imagery tasks have been shown to activate early visual cortex, which is deactivated by vestibular input. Thus, wepredicted that vestibular stimulation would disrupt high-resolution mental imagery; this prediction was confirmed. In addition, mental rotationtasks have been shown to activate posterior parietal cortex, which is also engaged in the processing of vestibular stimulation. As predicted,we also found that mental rotation is impaired during vestibular stimulation. In contrast, such stimulation did not affect performance of alow-imagery control task. These data document previously unsuspected interactions between the vestibular system and the high-level visualsystem

    Street crossing behavior in younger and older pedestrians: an eye- and head-tracking study

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    Background Crossing a street can be a very difficult task for older pedestrians. With increased age and potential cognitive decline, older people take the decision to cross a street primarily based on vehicles’ distance, and not on their speed. Furthermore, older pedestrians tend to overestimate their own walking speed, and could not adapt it according to the traffic conditions. Pedestrians’ behavior is often tested using virtual reality. Virtual reality presents the advantage of being safe, cost-effective, and allows using standardized test conditions. Methods This paper describes an observational study with older and younger adults. Street crossing behavior was investigated in 18 healthy, younger and 18 older subjects by using a virtual reality setting. The aim of the study was to measure behavioral data (such as eye and head movements) and to assess how the two age groups differ in terms of number of safe street crossings, virtual crashes, and missed street crossing opportunities. Street crossing behavior, eye and head movements, in older and younger subjects, were compared with non-parametric tests. Results The results showed that younger pedestrians behaved in a more secure manner while crossing a street, as compared to older people. The eye and head movements analysis revealed that older people looked more at the ground and less at the other side of the street to cross. Conclusions The less secure behavior in street crossing found in older pedestrians could be explained by their reduced cognitive and visual abilities, which, in turn, resulted in difficulties in the decision-making process, especially under time pressure. Decisions to cross a street are based on the distance of the oncoming cars, rather than their speed, for both groups. Older pedestrians look more at their feet, probably because of their need of more time to plan precise stepping movement and, in turn, pay less attention to the traffic. This might help to set up guidelines for improving senior pedestrians’ safety, in terms of speed limits, road design, and mixed physical-cognitive trainings

    ODELAY: A Large-scale Method for Multi-parameter Quantification of Yeast Growth.

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    Growth phenotypes of microorganisms are a strong indicator of their underlying genetic fitness and can be segregated into 3 growth regimes: lag-phase, log-phase, and stationary-phase. Each growth phase can reveal different aspects of fitness that are related to various environmental and genetic conditions. High-resolution and quantitative measurements of all 3 phases of growth are generally difficult to obtain. Here we present a detailed method to characterize all 3 growth phases on solid media using an assay called One-cell Doubling Evaluation of Living Arrays of Yeast (ODELAY). ODELAY quantifies growth phenotypes of individual cells growing into colonies on solid media using time-lapse microscopy. This method can directly observe population heterogeneity with each growth parameter in genetically identical cells growing into colonies. This population heterogeneity offers a unique perspective for understanding genetic and epigenetic regulation, and responses to genetic and environmental perturbations. While the ODELAY method is demonstrated using yeast, it can be utilized on any colony forming microorganism that is visible by bright field microscopy

    Microstability analysis of pellet fuelled discharges in MAST

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    Reactor grade plasmas are likely to be fuelled by pellet injection. This technique transiently perturbs the profiles, driving the density profile hollow and flattening the edge temperature profile. After the pellet perturbation, the density and temperature profiles relax towards their quasi-steady-state shape. Microinstabilities influence plasma confinement and will play a role in determining the evolution of the profiles in pellet fuelled plasmas. In this paper we present the microstability analysis of pellet fuelled H-mode MAST plasmas. Taking advantage of the unique capabilities of the MAST Thomson scattering system and the possibility of synchronizing the eight lasers with the pellet injection, we were able to measure the evolution of the post-pellet electron density and temperature profiles with high temporal and spatial resolution. These profiles, together with ion temperature profiles measured using a charge exchange diagnostic, were used to produce equilibria suitable for microstability analysis of the equilibrium changes induced by pellet injection. This analysis, carried out using the local gyrokinetic code GS2, reveals that the microstability properties are extremely sensitive to the rapid and large transient excursions of the density and temperature profiles, which also change collisionality and beta e significantly in the region most strongly affected by the pellet ablation.Comment: 21 pages, 10 figures. This is an author-created, un-copyedited version of an article submitted for publication in Plasma Physics and Controlled Fusion. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from i

    Effectiveness of a Staff Modeling Procedure on Increasing Appropriate Interactions Between a Mother and Child With Behavior Problems

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    AN ABSTRACT OF THE RESEARCH PAPER OF MITCHELL D. MAST, for the Master of Science degree in Behavior Analysis and Therapy, at Southern Illinois University Carbondale. TITLE: EFFECTIVENESS OF STAFF MODELING ON INCREASING APPROPRIATE INTERACTIONS BETWEEN A MOTHER AND A CHILD WITH BEHAVIOR PROBLEMS MAJOR PROFESSOR: Dr. Brandon Greene The present study was an attempt to determine the effect of a training program on altering the frequency and type of verbal interactions exhibited by a parent of a child with behavior problems. Data on verbal interactions between a mother and her child was gathered using the Systematic Observation of Family Interactions, a partial interval system for recording verbal interactions that evaluates interactions as either positive or negative. On some days staff assumed the role of parent during the meal routine in order to demonstrate a more positive interaction style. A focus was placed on decreasing the amount of negative affect and verbal statements, while increasing positive verbal statements and positive affect. Although this procedure was effective at reducing statements with negative affect made by the mother, it was found to be less effective at reducing her negative verbal statements. On other days, a more intensive prompting/modeling procedure was implemented where both staff and parent shared the parenting role during the meal. The degree to which interactions learned during mealtime generalized to a period when the dyad discussed the child’s day at school was then assessed. Additional training in the form of an after school discussion was conducted in order to provide a more appropriate way to debrief with the child after his school day
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