2,753 research outputs found

    DESENVOLVIMENTO E VALIDAÇÃO DE UM DISPOSITIVO PARA MENSURAÇÃO DA FLEXIBILIDADE POR MEIO DO ACELERÔMETRO EM CRIANÇAS

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    The objectives of this study were to develop and validate a computerized device to measure joint flexibility; to measure flexibility in children in elementary school aged 8 to 10 years using the Wells bank; to compare the data obtained by the Wells bank and the computerized device developed in the present study and evaluate the usability of the device. 215 volunteers participated in this research, aged between 8 and 10 years, 63.72% (137) were female and 36.28% (78) were male, duly enrolled in an educational institution in the Alto Tietê region. For data collection, the volunteers performed the flexibility test using the Wells bank and the computerized device developed in this research to assess flexibility. The computerized device it was made on a 3D printing technology printer. A usability evaluation was carried out with 15 Physical Education teachers for the product developed through a usability questionnaire based on the System Usability Scale (SUS) form, which contains 10 multiple-choice questions. The data obtained by the objective measures determined were evaluated in terms of frequency, mean and standard deviation. The arithmetic means of the three measurements performed at each stage were calculated. Mann-Whitney and Kruskal-Wallis tests and Spearman's correlation were performed for the investigation. For all analyses, significant differences were considered p<0.05. It is concluded that the computerized device to measure joint flexibility is capable of evaluating the range of motion in degrees, and was qualified as easy to handle by professionals in the field of physical education.Los objetivos de este estudio fueron desarrollar y validar un dispositivo computarizado para medir la flexibilidad articular; medir la flexibilidad en niños en la escuela primaria de 8 a 10 años a través del banco Wells; comparar los datos obtenidos por la base de datos Wells y el dispositivo computarizado desarrollado en el presente estudio y evaluar la usabilidad del dispositivo. Un total de 215 voluntarios participaron en esta investigación, con edades de 8 a 10 años, 63,72% (137) mujeres y 36,28% (78) hombres, debidamente matriculados en una institución educativa de la región del Alto Tietê. Para la recolección de datos, los voluntarios realizaron la prueba de flexibilidad utilizando la base de datos Wells y el dispositivo computarizado desarrollado en esta investigación para evaluar la flexibilidad. El dispositivo fue hecho de una impresora de tecnología de impresión 3D. Se realizó una evaluación de usabilidad con 15 profesores de Educación Física para el producto desarrollado a través del cuestionario de usabilidad basado en el formulario System Usability Scale (SUS) que contiene 10 preguntas de opción múltiple. Los datos obtenidos por las mediciones objetivas determinadas fueron evaluados para la frecuencia, media y desviación estándar. Se calcularon las medias aritméticas de las tres mediciones realizadas en cada etapa. Las pruebas de Mann-Whitney y Kruskal-Wallis y la correlación de Spearman se realizaron para la investigación. Para todos los análisis, se consideraron diferencias significativas p<0,05. Se concluye que el dispositivo computarizado para medir la flexibilidad articular es capaz de evaluar el rango de movimiento en grados, y fue calificado fácil de manejar por profesionales de la educación física.Os objetivos deste estudo foram desenvolver e validar um dispositivo computadorizado para mensurar a flexibilidade articular; mensurar a flexibilidade em crianças no ensino fundamental de 8 a 10 anos por meio do banco de Wells; comparar os dados alcançados pelo banco de Wells e o dispositivo computadorizado desenvolvido no presente estudo e avaliar a usabilidade do dispositivo. Participaram desta pesquisa 215 voluntários, com idade de 8 a 10 anos, sendo 63,72% (137) do sexo feminino e 36,28% (78) do sexo masculino, devidamente matriculados em uma instituição de ensino na região do Alto Tietê. Para coleta de dados, os voluntários realizaram o teste de flexibilidade utilizando o banco de Wells e o dispositivo computadorizado desenvolvido nessa pesquisa para avaliar a flexibilidade.O dispositivo foi confeccionado numa impressora de tecnologia de impressão 3D. Foi realizada uma avaliação da usabilidade com 15 professores de Educação Física para o produto desenvolvido através da interação de usabilidade baseada no formulário System Sustainability Scale (SUS) que contém 10 questões de múltipla-escolha. Os dados obtidos por medidas objetivas determinadas foram avaliadas quanto à frequência, média e desvio padrão. Foram seguidas como médias aritméticas das três medidas realizadas em cada etapa. Para investigar realizou-se os testes de Mann-Whitney e de Kruskal-Wallis e a tradução de Spearman. Para todas as análises foram consideradas diferenças significativas p<0,05.Conclui-se que o dispositivo computadorizado para medir a flexibilidade articular é capaz de avaliar em graus a amplitude de movimento

    The unexpected resurgence of Weyl geometry in late 20-th century physics

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    Weyl's original scale geometry of 1918 ("purely infinitesimal geometry") was withdrawn by its author from physical theorizing in the early 1920s. It had a comeback in the last third of the 20th century in different contexts: scalar tensor theories of gravity, foundations of gravity, foundations of quantum mechanics, elementary particle physics, and cosmology. It seems that Weyl geometry continues to offer an open research potential for the foundations of physics even after the turn to the new millennium.Comment: Completely rewritten conference paper 'Beyond Einstein', Mainz Sep 2008. Preprint ELHC (Epistemology of the LHC) 2017-02, 92 pages, 1 figur

    Prior dengue virus exposure shapes T Cell immunity to Zika Virus in humans

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    While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether pre-existing dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with Tetravalent Dengue Attenuated Vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors, but declines in DENV pre-exposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells form DENV pre-exposed donors selectively up-regulated granzyme B and PD1, as compared to DENV-naïve donors. Finally, we discovered that ZIKV structural proteins (E, prM and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins

    Search for Tidal Dwarf Galaxies Candidates in a Sample of Ultraluminous Infrared Galaxies

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    (ABRIDGED) Star-forming small galaxies made out of collisional debris have been found in a variety of merging systems. So far only a few of them are known in ULIRGs although they show clear signs of interactions. Whether external star formation may take place in such objects is an open question. The aim of this paper is to identify and characterise the physical and kinematic properties of the external star forming regions in a sample of ULIRGs, including TDG candidates, using optical IFS and high angular resolution HST imaging. We have found that the presence of external star-forming regions is common with 12 objects being identified in 5 ULIRGs. These regions show a large range of dynamical mass up to 1x10^{10} M_sun, with average sizes of ~750 pc. In addition, the line ratios, metallicities and H\alpha equivalent widths are typical of young bursts of star formation (age ~ 5-8 Myr), and similar to those of other TDG candidates. Their extinction corrected H\alpha luminosities lead to masses for the young stellar component of ~2x10^6 - 7x10^8 M_sun. The likelihood of survival of these regions as TDGs is discussed based on their structural and kinematic properties. Most of these systems follow the relation between effective radius and velocity dispersion found for globular clusters and Ellipticals, which suggests they are stable against internal motions. The stability against forces from the parent galaxy have been studied and a comparison of the data with the predictions of dynamical evolutionary models is also performed. Five regions out of twelve show High-Medium or High likelihood of survival. Our best candidate, which satisfy all the utilized criteria, is located in the advanced merger IRAS15250+3609 and presents a velocity field decoupled from the relatively distant parent galaxy.Comment: 14 pages, 7 figures; A&A accepte

    Measuring large-scale structure with quasars in narrow-band filter surveys

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    We show that a large-area imaging survey using narrow-band filters could detect quasars in sufficiently high number densities, and with more than sufficient accuracy in their photometric redshifts, to turn them into suitable tracers of large-scale structure. If a narrow-band optical survey can detect objects as faint as i=23, it could reach volumetric number densities as high as 10^{-4} h^3 Mpc^{-3} (comoving) at z~1.5 . Such a catalog would lead to precision measurements of the power spectrum up to z~3-4. We also show that it is possible to employ quasars to measure baryon acoustic oscillations at high redshifts, where the uncertainties from redshift distortions and nonlinearities are much smaller than at z<1. As a concrete example we study the future impact of J-PAS, which is a narrow-band imaging survey in the optical over 1/5 of the unobscured sky with 42 filters of ~100 A full-width at half-maximum. We show that J-PAS will be able to take advantage of the broad emission lines of quasars to deliver excellent photometric redshifts, \sigma_{z}~0.002(1+z), for millions of objects.Comment: Matches version published in MNRAS (2012
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