Physical education and health promotion: a review of theoretical-methodological perspectives in Brazil

Na complexidade da atuação da educação física na promoção da saúde é possível identificar diferentes perspectivas epistemológicas no saber-fazer dos trabalhadores. A intenção deste artigo, de caráter ensaístico, é apontar estas perspectivas, buscando perceber suas influencias teóricas e históricas, assim como os caminhos que vem percorrendo em publicações, autores que se destacam e focos de interesse. Por meio de buscas não sistemáticas em bancos de dados e periódicos, foram encontradas publicações e marcos legais que ligam educação física e promoção da saúde. Conclui-se a existência de quatro perspectivas teórico-metodológicas: epidemiológica, aponta a relação positiva entre a atividade física e a menor incidência de doenças; pós estruturalista ligada a produção de subjetividade e relações sociais, na promoção da saúde; materialismo histórico-dialético reflete a respeito das inter-relações sociais e dos meios de produção e exploração; e a perspectiva integrativa ligada a uma perspectiva vitalista, onde a saúde passa a ser percebida como a busca da inteireza do ser. É importante ressaltar que a apresentação destas perspectivas de forma linear é um recurso didático, mas que na realidade da prática profissional nem sempre mostram-se com fronteiras claramente delineadas, podendo se apresentar de forma hibrida e inter-relacionada.In the complexity of the performance of Physical Education in health promotion, it is possible to identify different epistemological perspectives in the know-how of workers. The aim of this article, of an essay character, is to point out these perspectives, seeking to perceive its theoretical and historical influences, as well as the paths it has been going through in publications, authors that stand out and focuses of interest. Through non-systematic searches in databases and journals, publications and legal frameworks linking Physical Education and health promotion were studied. The existence of four theoretical-methodological perspectives was found: epidemiological, which points out the positive relation between physical activity and the lower incidence of diseases; post structuralist, which links to the production of subjectivity and social relations in the promotion of health; historical-dialectical materialism, which reflects on the social interrelationships and the means of production and exploitation; and the integrative perspective, which links to a vitalist perspective, where health comes to be perceived as the pursuit of the wholeness of being. It is important to emphasize that the presentation of these perspectives in a linear way is a didactic resource, but that in the reality of the professional practice they do not always show themselves with boundaries clearly defined, being able to present themselves in a hybrid and interrelated way.Facultad de Humanidades y Ciencias de la Educació

Abordagem aos números decimais e suas operações: a importância de uma “eficaz navegação” entre representações

Este artigo foca alguns aspectos e ideias de tarefas a serem exploradas com os alunos relativamente à multiplicação de números decimais, discutindo o conhecimento matemático para o ensino subjacente à preparação e à aplicação de tais tarefas. Discutem-se algumas representações dessa multiplicação e a importância de um rico e fundamentado conhecimento matemático para o ensino como promotor de um conhecimento matemático com significado, por parte dos alunos, por via de uma eficaz navegação entre representações. A escolha das representações pretende, aqui, tornar também evidente o motivo pelo qual, ao multiplicar dois números decimais, o número de casas decimais do produto é a soma dos factores. O texto tem por base um trabalho colaborativo desenvolvido ao longo dos últimos anos com professores do 1º ciclo do ensino básico (alunos com idade entre seis e nove anos), tendo como ponto de partida as discussões ocorridas ali, as reflexões subjacentes e as maiores dificuldades sentidas tanto pelos alunos, como pelos próprios professores. É de salientar que o facto de se abordarem conjuntamente representações dos números em decimais e fraccionários possibilita que os alunos se consciencializem de diferentes representações para um mesmo valor, o mesmo ocorrendo quando se utilizam diversas quantidades como unidades discretas, ou distintos tipos de unidades. Apenas se o professor for detentor de um sustentado conhecimento matemático para o ensino ele poderá recorrer a essas distintas representações de maneira construtiva e de modo a que tenham significado para os alunos

Gamma Radiation from PSR B1055-52

The telescopes on the Compton Gamma Ray Observatory (CCRO) have observed PSR B1055-52 a number of times between 1991 and 1998. From these data, a more detailed picture of the gamma radiation from this source has been developed, showing several characteristics which distinguish this pulsar: the light curve is complex; there is no detectable unpulsed emission; the energy spectrum is flat, with no evidence of a sharp high-energy cutoff up to greater than 4 GeV. Comparisons of the gamma-ray data with observations at longer wavelengths show that no two of the known gamma-ray pulsars have quite the same characteristics; this diversity makes interpretation in terms of theoretical models difficult

Conformational Reorganization of the SARS Coronavirus Spike Following Receptor Binding: Implications for Membrane Fusion

The SARS coronavirus (SARS-CoV) spike is the largest known viral spike molecule, and shares a similar function with all class 1 viral fusion proteins. Previous structural studies of membrane fusion proteins have largely used crystallography of static molecular fragments, in isolation of their transmembrane domains. In this study we have produced purified, irradiated SARS-CoV virions that retain their morphology, and are fusogenic in cell culture. We used cryo-electron microscopy and image processing to investigate conformational changes that occur in the entire spike of intact virions when they bind to the viral receptor, angiotensin-converting enzyme 2 (ACE2). We have shown that ACE2 binding results in structural changes that appear to be the initial step in viral membrane fusion, and precisely localized the receptor-binding and fusion core domains within the entire spike. Furthermore, our results show that receptor binding and subsequent membrane fusion are distinct steps, and that each spike can bind up to three ACE2 molecules. The SARS-CoV spike provides an ideal model system to study receptor binding and membrane fusion in the native state, employing cryo-electron microscopy and single-particle image analysis

Insulin Degrading Enzyme Induces a Conformational Change in Varicella-Zoster Virus gE, and Enhances Virus Infectivity and Stability

Varicella-zoster virus (VZV) glycoprotein E (gE) is essential for virus infectivity and binds to a cellular receptor, insulin-degrading enzyme (IDE), through its unique amino terminal extracellular domain. Previous work has shown IDE plays an important role in VZV infection and virus cell-to-cell spread, which is the sole route for VZV spread in vitro. Here we report that a recombinant soluble IDE (rIDE) enhances VZV infectivity at an early step of infection associated with an increase in virus internalization, and increases cell-to-cell spread. VZV mutants lacking the IDE binding domain of gE were impaired for syncytia formation and membrane fusion. Pre-treatment of cell-free VZV with rIDE markedly enhanced the stability of the virus over a range of conditions. rIDE interacted with gE to elicit a conformational change in gE and rendered it more susceptible to proteolysis. Co-incubation of rIDE with gE modified the size of gE. We propose that the conformational change in gE elicited by IDE enhances infectivity and stability of the virus and leads to increased fusogenicity during VZV infection. The ability of rIDE to enhance infectivity of cell-free VZV over a wide range of incubation times and temperatures suggests that rIDE may be useful for increasing the stability of varicella or zoster vaccines

The Association of Systemic Microvascular Changes with Lung Function and Lung Density: A Cross-Sectional Study

10.1371/journal.pone.0050224PLoS ONE712

Imaging Single Retrovirus Entry through Alternative Receptor Isoforms and Intermediates of Virus-Endosome Fusion

A large group of viruses rely on low pH to activate their fusion proteins that merge the viral envelope with an endosomal membrane, releasing the viral nucleocapsid. A critical barrier to understanding these events has been the lack of approaches to study virus-cell membrane fusion within acidic endosomes, the natural sites of virus nucleocapsid capsid entry into the cytosol. Here we have investigated these events using the highly tractable subgroup A avian sarcoma and leukosis virus envelope glycoprotein (EnvA)-TVA receptor system. Through labeling EnvA pseudotyped viruses with a pH-sensitive fluorescent marker, we imaged their entry into mildly acidic compartments. We found that cells expressing the transmembrane receptor (TVA950) internalized the virus much faster than those expressing the GPI-anchored receptor isoform (TVA800). Surprisingly, TVA800 did not accelerate virus uptake compared to cells lacking the receptor. Subsequent steps of virus entry were visualized by incorporating a small viral content marker that was released into the cytosol as a result of fusion. EnvA-dependent fusion with TVA800-expressing cells occurred shortly after endocytosis and delivery into acidic endosomes, whereas fusion of viruses internalized through TVA950 was delayed. In the latter case, a relatively stable hemifusion-like intermediate preceded the fusion pore opening. The apparent size and stability of nascent fusion pores depended on the TVA isoforms and their expression levels, with TVA950 supporting more robust pores and a higher efficiency of infection compared to TVA800. These results demonstrate that surface receptor density and the intracellular trafficking pathway used are important determinants of efficient EnvA-mediated membrane fusion, and suggest that early fusion intermediates play a critical role in establishing low pH-dependent virus entry from within acidic endosomes

Geothermal Heat Recovery Complex: Large-Scale, Deep Direct-Use System in a Low-Temperature Sedimentary Basin

This feasibility study is the first assessment of geothermal resources in the Illinois Basin (ILB). The breadth of previous, geologic-based research in the ILB supported this thorough determination of geothermal resources in the Mt. Simon Sandstone (MSS) and the techno-economics of establishing a geothermal energy system (GES) at the University of Illinois at Urbana-Champaign (U of IL). An integrated, multi-disciplinary scientific and engineering approach allowed simulations for both the belowground and aboveground components of the GES that would meet the required baseload of 2 MMBtu/hr at the end-user agricultural research facilities (ARFs). This assessment contributes to the broader discussion surrounding the U of IL’s goal to achieve net-zero carbon emissions by 2050. Furthermore, a rigorous evaluation of the ILB’s geological, hydrological, and thermal frameworks facilitated a broader assessment of the feasibility of applying deep direct-use (DDU) technologies at facilities (e.g., military installations, hospitals, and school campuses) in other geographical areas in the ILB, and in other sedimentary basins in midcontinent of the US.U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Geothermal Technologies Office Award Number DE-EE0008106Ope