273 research outputs found

    The OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS): Spectral Maps of the Asteroid Bennu

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    The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) is a point spectrometer covering the spectral range of 0.4 to 4.3 microns (25,000-2300 cm-1). Its primary purpose is to map the surface composition of the asteroid Bennu, the target asteroid of the OSIRIS-REx asteroid sample return mission. The information it returns will help guide the selection of the sample site. It will also provide global context for the sample and high spatial resolution spectra that can be related to spatially unresolved terrestrial observations of asteroids. It is a compact, low-mass (17.8 kg), power efficient (8.8 W average), and robust instrument with the sensitivity needed to detect a 5% spectral absorption feature on a very dark surface (3% reflectance) in the inner solar system (0.89-1.35 AU). It, in combination with the other instruments on the OSIRIS-REx Mission, will provide an unprecedented view of an asteroid's surface.Comment: 14 figures, 3 tables, Space Science Reviews, submitte

    Influence of Stress and Dietary Natural-Source Vitamin E on Nonspecific Immunocompetence, Tissue Tocopherol Composition, and Postslaughter Fillet Oxidative Stability in Sunshine Bass

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    We evaluated the effects of stressor exposure and super-requirement levels of RRR-atocopheryl acetate (natural-source vitamin E [NSVE]) on production performance and nonspecific immunocompetency of juvenile sunshine bass (female white bass Morone chrysops X male striped bass M. saxatilis). Stressor exposure elicited physiological changes consistent with the generalized stress response, and the magnitude of responses generally mirrored stressor severity. Stressor exposure resulted in lower fillet peroxides and greater aldehydes after short-term frozen storage, whereas increasing dietary NSVE was associated with a nonsignificant reduction in aldehydes after long-term storage. Fillet a-tocopherol content increased linearly with dietary NSVE, exceeding reported tissue levels achieved with synthetic vitamin E (SYNE). Although we observed no significant immunological effects of stress or dietary NSVE content, sampling time and high individual-to-individual variation probably restricted our ability to resolve statistical significance. Similar results of vitamin E supplementation have previously been reported; however, the effective dietary concentrations we observed for NSVE are low in comparison with values reported for SYNE. The potential of RRR-a-tocopheryl acetate as a highly active vitamin E source for aquaculture feeds warrants further evaluation of the relative suitability of NSVE in meeting the demands of optimal aquaculture nutrition

    Designing electronic collaborative learning environments

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    Electronic collaborative learning environments for learning and working are in vogue. Designers design them according to their own constructivist interpretations of what collaborative learning is and what it should achieve. Educators employ them with different educational approaches and in diverse situations to achieve different ends. Students use them, sometimes very enthusiastically, but often in a perfunctory way. Finally, researchers study them and—as is usually the case when apples and oranges are compared—find no conclusive evidence as to whether or not they work, where they do or do not work, when they do or do not work and, most importantly, why, they do or do not work. This contribution presents an affordance framework for such collaborative learning environments; an interaction design procedure for designing, developing, and implementing them; and an educational affordance approach to the use of tasks in those environments. It also presents the results of three projects dealing with these three issues

    Towards the automated reduction and calibration of SCUBA data from the James Clerk Maxwell Telescope

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    The Submillimetre Common User Bolometer Array (SCUBA) instrument has been operating on the James Clerk Maxwell Telescope (JCMT) since 1997. The data archive is now sufficiently large that it can be used to investigate instrumental properties and the variability of astronomical sources. This paper describes the automated calibration and reduction scheme used to process the archive data with particular emphasis on `jiggle-map' observations of compact sources. We demonstrate the validity of our automated approach at both 850- and 450-microns and apply it to several of the JCMT secondary flux calibrators. We determine light curves for the variable sources IRC+10216 and OH231.8. This automation is made possible by using the ORAC-DR data reduction pipeline, a flexible and extensible data reduction pipeline that is used on UKIRT and the JCMT.Comment: 9 pages, 8 figures, accepted for publication in Monthly Notices of the Royal Astronomical Societ

    A blind detection of a large, complex, Sunyaev--Zel'dovich structure

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    We present an interesting Sunyaev-Zel'dovich (SZ) detection in the first of the Arcminute Microkelvin Imager (AMI) 'blind', degree-square fields to have been observed down to our target sensitivity of 100{\mu}Jy/beam. In follow-up deep pointed observations the SZ effect is detected with a maximum peak decrement greater than 8 \times the thermal noise. No corresponding emission is visible in the ROSAT all-sky X-ray survey and no cluster is evident in the Palomar all-sky optical survey. Compared with existing SZ images of distant clusters, the extent is large (\approx 10') and complex; our analysis favours a model containing two clusters rather than a single cluster. Our Bayesian analysis is currently limited to modelling each cluster with an ellipsoidal or spherical beta-model, which do not do justice to this decrement. Fitting an ellipsoid to the deeper candidate we find the following. (a) Assuming that the Evrard et al. (2002) approximation to Press & Schechter (1974) correctly gives the number density of clusters as a function of mass and redshift, then, in the search area, the formal Bayesian probability ratio of the AMI detection of this cluster is 7.9 \times 10^4:1; alternatively assuming Jenkins et al. (2001) as the true prior, the formal Bayesian probability ratio of detection is 2.1 \times 10^5:1. (b) The cluster mass is MT,200 = 5.5+1.2\times 10^14h-1M\odot. (c) Abandoning a physical model with num- -1.3 70 ber density prior and instead simply modelling the SZ decrement using a phenomenological {\beta}-model of temperature decrement as a function of angular distance, we find a central SZ temperature decrement of -295+36 {\mu}K - this allows for CMB primary anisotropies, receiver -15 noise and radio sources. We are unsure if the cluster system we observe is a merging system or two separate clusters.Comment: accepted MNRAS. 12 pages, 9 figure

    Percepção de estudantes de psicologia sobre a informática em sua formação profissional

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    Neste artigo analisa-se uma pesquisa de natureza qualitativa, cujo objetivo era explorar a percepção de 45 alunos de psicologia de diferentes universidades da cidade de Santiago do Chile, sobre a incorporação da informática como apoio para a aprendizagem em sua formação profissional. A informação foi coletada através de entrevistas semiestruturadas e analisou-se mediante o processo de codificação da Teoría Fundamentada. Os resultados mostram como categorias principais, o conhecimento da informática, a valoração da informática, e os fatores que obstaculizam o uso desta. Da codificação seletiva se desprende uma alta valoração da informática como ferramenta econômica e cômoda, mas também se observa uma alta reticência dos alunos diante de sua utilização no trabalho profissional tradicional do psicólogo. Encontraram-se fatores pessoais e institucionais nos que se baseia a valoração, a motivação e o nível de conhecimento dos estudantes diante do uso de ferramentas informáticas.This paper analyses a qualitative research aimed to exploring the perception of 45 psychology students from different universities in Santiago de Chile, about incorporating information systems to support learning in their professional training. Data were collected through semi structured interviews and their analysis was based on Grounded Theory's coding process. Results show that the major categories are computer knowledge, appreciation of computers and factors that hinder their use. From the selective coding a positive evaluation emerges of information systems as an economic and useful tool. However, there is also a high reluctance on the part of the students regarding the use of such tools in the psychologist' traditional professional work. Personal and organizational factors were found as bases for students' assessment, motivation and level of knowledge facing the use of these tools.En este artículo se analiza una investigación de naturaleza cualitativa, cuyo objetivo era explorar la percepción de 45 alumnos de psicología de diferentes universidades de la ciudad de Santiago de Chile, sobre la incorporación de la informática como apoyo para el aprendizaje en su formación profesional. La información se recolectó a través de entrevistas semiestructuradas y se analizó mediante el proceso de codificación de la Teoría Fundamentada. Los resultados muestran como categorías principales, el conocimiento de la informática, la valoración de la informática, y los factores que obstaculizan el uso de ésta. De la codificación selectiva se desprende una alta valoración de la informática como herramienta económica y cómoda, pero también se observa una alta reticencia de los alumnos frente a su utilización en el trabajo profesional tradicional del psicólogo. Se encontraron factores personales e institucionales en los cuales se fundamenta la valoración, la motivación y el nivel de conocimiento de los estudiantes frente al uso de herramientas informáticas

    INCITE: A randomised trial comparing constraint induced movement therapy and bimanual training in children with congenital hemiplegia

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    Background: Congenital hemiplegia is the most common form of cerebral palsy (CP) accounting for 1 in 1300 live births. These children have limitations in capacity to use the impaired upper limb and bimanual coordination deficits which impact on daily activities and participation in home, school and community life. There are currently two diverse intensive therapy approaches. Traditional therapy has adopted a bimanual approach (BIM training) and recently, constraint induced movement therapy (CIMT) has emerged as a promising unimanual approach. Uncertainty remains about the efficacy of these interventions and characteristics of best responders. This study aims to compare the efficacy of CIMT to BIM training to improve outcomes across the ICF for school children with congenital hemiplegia

    Focus on Function – a randomized controlled trial comparing two rehabilitation interventions for young children with cerebral palsy

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    <p>Abstract</p> <p>Background</p> <p>Children with cerebral palsy receive a variety of long-term physical and occupational therapy interventions to facilitate development and to enhance functional independence in movement, self-care, play, school activities and leisure. Considerable human and financial resources are directed at the "intervention" of the problems of cerebral palsy, although the available evidence supporting current interventions is inconclusive. A considerable degree of uncertainty remains about the appropriate therapeutic approaches to manage the habilitation of children with cerebral palsy. The primary objective of this project is to conduct a multi-site randomized clinical trial to evaluate the efficacy of a task/context-focused approach compared to a child-focused remediation approach in improving performance of functional tasks and mobility, increasing participation in everyday activities, and improving quality of life in children 12 months to 5 years of age who have cerebral palsy.</p> <p>Method/Design</p> <p>A multi-centred randomized controlled trial research design will be used. Children will be recruited from a representative sample of children attending publicly-funded regional children's rehabilitation centers serving children with disabilities in Ontario and Alberta in Canada. Target sample size is 220 children with cerebral palsy aged 12 months to 5 years at recruitment date. Therapists are randomly assigned to deliver either a context-focused approach or a child-focused approach. Children follow their therapist into their treatment arm. Outcomes will be evaluated at baseline, after 6 months of treatment and at a 3-month follow-up period. Outcomes represent the components of the International Classification of Functioning, Disability and Health, including body function and structure (range of motion), activities (performance of functional tasks, motor function), participation (involvement in formal and informal activities), and environment (parent perceptions of care, parental empowerment).</p> <p>Discussion</p> <p>This paper presents the background information, design and protocol for a randomized controlled trial comparing a task/context-focused approach to a child-focused remediation approach in improving functional outcomes for young children with cerebral palsy.</p> <p>Trial registration</p> <p>[clinical trial registration #: NCT00469872]</p

    The Physics of the B Factories

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    This work is on the Physics of the B Factories. Part A of this book contains a brief description of the SLAC and KEK B Factories as well as their detectors, BaBar and Belle, and data taking related issues. Part B discusses tools and methods used by the experiments in order to obtain results. The results themselves can be found in Part C
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