413 research outputs found

    Extravehicular activities limitations study. Volume 1: Physiological limitations to extravehicular activity in space

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    This report contains the results of a comprehensive literature search on physiological aspects of EVA. Specifically, the topics covered are: (1) Oxygen levels; (2) Optimum EVA work; (3) Food and Water; (4) Carbon dioxide levels; (5) Repetitive decompressions; (6) Thermal, and (7) Urine collection. The literature was assessed on each of these topics, followed by statements on conclusions and recommended future research needs

    Coinductive subtyping for abstract compilation of object-oriented languages into Horn formulas

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    In recent work we have shown how it is possible to define very precise type systems for object-oriented languages by abstractly compiling a program into a Horn formula f. Then type inference amounts to resolving a certain goal w.r.t. the coinductive (that is, the greatest) Herbrand model of f. Type systems defined in this way are idealized, since in the most interesting instantiations both the terms of the coinductive Herbrand universe and goal derivations cannot be finitely represented. However, sound and quite expressive approximations can be implemented by considering only regular terms and derivations. In doing so, it is essential to introduce a proper subtyping relation formalizing the notion of approximation between types. In this paper we study a subtyping relation on coinductive terms built on union and object type constructors. We define an interpretation of types as set of values induced by a quite intuitive relation of membership of values to types, and prove that the definition of subtyping is sound w.r.t. subset inclusion between type interpretations. The proof of soundness has allowed us to simplify the notion of contractive derivation and to discover that the previously given definition of subtyping did not cover all possible representations of the empty type

    Cognitive group therapy for depressive students: The case study

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    The aims of this study were to assess whether a course of cognitive group therapy could help depressed students and to assess whether assimilation analysis offers a useful way of analysing students' progress through therapy. “Johanna” was a patient in a group that was designed for depressive students who had difficulties with their studies. The assimilation of Johanna's problematic experience progressed as the meetings continued from level one (unpleasant thoughts) to level six (solving the problem). Johanna's problematic experience manifested itself as severe and excessive criticism towards herself and her study performance. As the group meetings progressed, Johanna found a new kind of tolerance that increased her determination and assertiveness regarding the studies. The dialogical structure of Johanna's problematic experience changed: she found hope and she was more assertive after the process. The results indicated that this kind of psycho-educational group therapy was an effective method for treating depression. The assimilation analysis offered a useful way of analysing the therapy process

    Re-evaluating the Self-Report Habit Index: the cases of Physical Activity and Snacking habits

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    Objective. The Self-Report Habit Index (SRHI) was originally reported as one-dimensional (Verplanken and Orbell, 2003). Nevertheless, habit has been described as characterized by several features, and one-dimensional models for the SRHI have shown poor fit. Therefore, we aimed to compare multi-dimensional models with a one-dimension model in both snacking and physical activity habits, besides examining further instrument characteristics. Design. A cross-sectional study was conducted with high school and university students (n = 555). Main outcome measure. The SRHI adapted for physical activity and for snaking habits was applied at one single time. Results. Nested models with one factor, two factors, and three factors were compared. Then, a hierarchical second-order model was tested, and further validity issues, as well as invariance between habits, were examined. Three-dimensional models represented a better fit for both habits. However, fit was still non-adequate in the snacking version. Also, discriminant validity concerns raised for the physical activity SRHI. Also, invariance between the snacking and the physical activity versions was not confirmed. Conclusions. Considering the SRHI as composed by the dimensions of “lack of awareness”, “lack of control”, and “history of behavioural repetition” seems to be more accurate. Nevertheless, our findings suggest that further research is needed.Universidad de Costa Rica/[723-B7-306]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

    Gender-based food intake stereotype scale (GBFISS) for adolescents: development and psychometric evaluation

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    Objective. The study aimed to develop and test the validity and reliability of a gender-based food intake stereotype scale (GBFISS) to further the understanding of gender stereotype influences on food intake. Design. Two cross-sectional studies were conducted among adolescents. In the first one (n = 611), exploratory and confirmatory factor analyses were performed on subsamples to identify and cross-validate the scale’s structure. Evidence of concurrent validity (correlation with sexism) was also examined. In the second study (n = 813), confirmatory factor analysis was conducted to confirm the scale’s dimensionality on a different sample. Further evidence of construct validity (correlations with food intake and social desirability) was examined. Invariance was tested for different features as well. Main outcome. The Gender-Based Food Intake Stereotype Scale. Results. Factor analyses on the first and second studies helped identify and confirm the GBFISS as a three-dimensional scale. The studies also provided evidence of construct validity. Support for invariance by gender and age was found, and reliability was acceptable. Conclusion. The evidence suggests that the GBFISS is valid and reliable. Further research is recommended. The contribution of gender stereotypes, as measured by the GBFISS, to well-established health behavior models should be examined.Ministerio de Salud/[DM-FG-4854-14 and DM-FG.1748-2018]//Costa RicaFundación INCIENSA/[]/FUNIN/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Sociales::Instituto de Investigaciones Psicológicas (IIP

    Addressing the needs of children with disabilities experiencing disaster or terrorism

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    Purpose of review: This paper reviews the empirical literature on psychosocial factors relating to children with disabilities in the context of disaster or terrorism. Recent findings: Research indicates individuals with disabilities experience increased exposure to hazards due to existing social disparities and barriers associated with disability status. However, studies on the psychological effects of disaster/terrorism on children with preexisting disabilities are exceedingly few and empirical evidence of the effectiveness of trauma-focused therapies for this population is limited. Secondary adversities, including social stigma and health concerns, also compromise the recovery of these children post-disaster/terrorism. Schools and teachers appear to be particularly important in the recovery of children with disabilities to disaster. Disasters, terrorism, and war all contribute to the incidence of disability, as well as disproportionately affect children with preexisting disabilities. Summary: Disaster preparedness interventions and societal changes are needed to decrease the disproportionate environmental and social vulnerability of children with disabilities to disaster and terrorism

    Assessing young people's political engagement: a critical and systematic literature review of the instruments used to measure political engagement

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    Over the past few decades, there has been an increasing interest in understanding youth political engagement. However, it has been argued that the instruments used to assess the concept often lack adequate validation, and this is important as this practice may result in biased statistical conclusions. Consequently, the main aim of the present study was to systematically review, summarize, and critique the extant research evidence on the development of psychometric instruments that assess young people’s political engagement. Following a systematic review of the literature, seven instruments were identified that were both valid and reliable, but none explicitly assessed young people’s political engagement. Instead, they considered broad concepts and/or dimensions related to political engagement. Emphasising the lack of statistically robust standardised measurement tools that empirically assess young people’s political engagement, the available evidence confirms the pressing need to adopt a robust psychometric approach to assess political engagement in youth
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