720 research outputs found

    Professores do ensino secundário, na fase da experimentação e diversificação, em cursos de formação continuada sobre inovação curricular de física moderna

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    Neste trabalho, procuramos, através de uma pesquisa qualitativa, realizada por meio de questionário e entrevistas, analisar o desenvolvimento profissional de três professores do ensino secundário que participaram de três cursos de formação continuada sobre Física Moderna. Segundo os professores, a falta desses conteúdos na formação inicial e a necessidade de atualização foram as principais motivações para buscar novos conhecimentos. A pesquisa também indica que os cursos, além de auxiliarem os professores na inserção de novos conteúdos, também apresentam novas metodologias que podem ser utilizadas nos conteúdos tradicionais. E por fim, os professores afirmaram que a falta de infraestrutura das escolas é um dos principais fatores que dificultam a inserção desses conteúdos em sala de aula

    Parental origin of the two additional haploid sets of chromosomes in an embryo with tetraploidy

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    We report on the molecular investigations performed on an embryo with tetraploidy, karyotype 92,XXXY. The embryo was spontaneously aborted after eight weeks of gestation. Molecular analyses were performed in order to determine the parental origin and mode of formation of the two additional haploid sets of chromosomes. Microsatellite markers mapping to pericentromeric chromosome regions were used. Our results show a maternal origin of one additional set of chromosomes most likely due to the incorporation of the polar body of meiosis I and a paternal origin of the second additional set of chromosomes most likely due to dispermy. The karyotype 92,XXXY is rather unusual, indeed the vast majority of cases with tetraploidy have the karyotypes 92,XXXX or 92,XXYY. To the best of our knowledge this is the first case with 92,XXXY for which molecular investigations have been performed

    openWAR: An Open Source System for Evaluating Overall Player Performance in Major League Baseball

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    Within baseball analytics, there is substantial interest in comprehensive statistics intended to capture overall player performance. One such measure is Wins Above Replacement (WAR), which aggregates the contributions of a player in each facet of the game: hitting, pitching, baserunning, and fielding. However, current versions of WAR depend upon proprietary data, ad hoc methodology, and opaque calculations. We propose a competitive aggregate measure, openWAR, that is based upon public data and methodology with greater rigor and transparency. We discuss a principled standard for the nebulous concept of a "replacement" player. Finally, we use simulation-based techniques to provide interval estimates for our openWAR measure.Comment: 27 pages including supplemen

    Sphingosine 1-phosphate modulates antigen capture by murine langerhans cells via the S1P2 receptor subtype

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    Dendritic cells (DCs) play a pivotal role in the development of cutaneous contact hypersensitivity (CHS) and atopic dermatitis as they capture and process antigen and present it to T lymphocytes in the lymphoid organs. Recently, it has been indicated that a topical application of the sphingolipid sphingosine 1-phosphate (S1P) prevents the inflammatory response in CHS, but the molecular mechanism is not fully elucidated. Here we indicate that treatment of mice with S1P is connected with an impaired antigen uptake by Langerhans cells (LCs), the initial step of CHS. Most of the known actions of S1P are mediated by a family of five specific G protein-coupled receptors. Our results indicate that S1P inhibits macropinocytosis of the murine LC line XS52 via S1P2 receptor stimulation followed by a reduced phosphatidylinositol 3-kinase (PI3K) activity. As down-regulation of S1P2 not only diminished S1P-mediated action but also enhanced the basal activity of LCs on antigen capture, an autocrine action of S1P has been assumed. Actually, S1P is continuously produced by LCs and secreted via the ATP binding cassette transporter ABCC1 to the extracellular environment. Consequently, inhibition of ABCC1, which decreased extracellular S1P levels, markedly increased the antigen uptake by LCs. Moreover, stimulation of sphingosine kinase activity, the crucial enzyme for S1P formation, is connected not only with enhanced S1P levels but also with diminished antigen capture. These results indicate that S1P is essential in LC homeostasis and influences skin immunity. This is of importance as previous reports suggested an alteration of S1P levels in atopic skin lesions

    Onium Salts of Sulfur-Containing Oxyanions Resulting from Reaction of Sulfur(IV) Oxide with Aqueous Solutions of 1,2-Diamines and Morpholine

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    Reaction products have been isolated from SO2–L–H2O–О2 systems (L = ethylenediamine, N,N,N',N'-tetramethylethylenediamine, piperazine, and morpholine) as onium salts [H3NCH2CH2NH3]SO4, [(CH3)2NHCH2CH2NH(CH3)2]SO4, [(CH3)2NHCH2CH2NH(CH3)2]S2O6 ⋅ H2O, [C4H8N2H4]SO3 ⋅ H2O, [C4H8N2H4]S2O6, [C4H8N2H4]SO4 ⋅ H2O, [O(C2H4)2NH2]2SO4 ⋅ H2O. The prepared compounds have been characterized by X-ray diffraction analysis, X-ray powder diffraction, IR and mass spectroscopy

    Weldability of Duplex Stainless Steels - Thermal Cycle and Nitrogen Effects : Duplex stainless steel weld microstructures were investigated as a function of weld thermal cycles and shielding gas nitrogen content

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    Much development work has been performed worldwide on the welding of duplex stainless steels (DSSs), where losses in base metal nitrogen during welding have been compensated by filler metal and nitrogen additions to the shielding gas. However, some heat-affected zone (HAZ) microstructural changes have not always responded consistently to nitrogen mixtures added to the shielding gas. In this work, DSS weld microstructures were investigated as a function of weld thermal cycles and shielding gas nitrogen content. Physical simulations, actual gas tungsten arc welding (GTAW) in controlled atmospheres, and entrapped nitrogen measurements were used to relate to the weld austenite-to-ferrite (A/F) phase ratios. Results showed the thermal cycles had a stronger effect on the weld A/F ratio than shielding gas nitrogen content. Physical simulations and actual GTAW trials also showed the A/F ratio changes in the opposite way in the fusion zone than in the HAZ. Reheating was also found to have an important effect on the microstructure. The above findings should allow fabricators to better design the welding process with DSS. Better control of nitrogen-containing shielding gas mixtures, along with heat input limitations, should result in more consistent weld properties and wider use of DSS by industry

    Conducting clinical trials in persons with Down syndrome : summary from the NIH INCLUDE Down syndrome clinical trials readiness working group

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    The recent National Institute of Health (NIH) INCLUDE (INvestigation of Co-occurring conditions across the Lifespan to Understand Down syndromE) initiative has bolstered capacity for the current increase in clinical trials involving individuals with Down syndrome (DS). This new NIH funding mechanism offers new opportunities to expand and develop novel approaches in engaging and effectively enrolling a broader representation of clinical trials participants addressing current medical issues faced by individuals with DS. To address this opportunity, the NIH assembled leading clinicians, scientists, and representatives of advocacy groups to review existing methods and to identify those areas where new approaches are needed to engage and prepare DS populations for participation in clinical trial research. This paper summarizes the results of the Clinical Trial Readiness Working Group that was part of the INCLUDE Project Workshop: Planning a Virtual Down Syndrome Cohort Across the Lifespan Workshop held virtually September 23 and 24, 2019
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