586 research outputs found

    PROPOSTA DE UM PERCURSO DE ESTUDO E PESQUISA PARA FORMAÇÃO DOCENTE SOBRE O ENSINO DE EQUAÇÕES POLINOMIAIS DO PRIMEIRO GRAU COM UMA INCÓGNITA

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    In this article, we resume part of a doctoral research that aimed to analyze comparatively the praxeologies in official documents, in the textbook, and in the teacher's praxeology concerning the teaching of first-degree polynomial equations with one unknown variable. To do so, we expanded the discussions that came from the research that resulted in a proposal of a study and research path for teacher education (SRP-TE) for teaching first degree polynomial equations with one unknown variable. The SRP-TE is based on some conceptual elements that are part of the device, such as: the reference epistemological model (REM) and the types of mathematical organizations (MO) that will be presented later. The device comes as a methodological proposal for basic education teacher training to understand the rationale of polynomial equations of the first degree with one unknown variable and what didactic organization to aim for the initial or continuing education of these professionals. The research is based on the anthropological theory of didactics, more specifically on the theoretical and methodological constructs of a SRP. Furthermore, we started by presenting an REM for teaching polynomial equations of the first degree with one unknown variable. This ERM is the lever to build didactic organizations that enable the study and research activities arising from the proposed question to carry out the activities that would lead to the resolution of the derived questions. For this reason, we proposed a didactic device (SRP-TE) through which the elementary school teacher could have access to a vision not only amplified but regulated/adjusted by the three structuring principles of the SRP and the fundamental dialectics of how to study and teach polynomial equations of the first degree with one unknown.Retomamos neste artigo uma parte de pesquisa de doutorado que teve como objetivo analisar comparativamente as praxeologias em documentos oficiais, no livro didático e do professor, referentes ao ensino de equações polinomiais do primeiro grau com uma incógnita. Para tanto, expandimos as discussões oriundas da pesquisa que resultaram em uma proposta de um percurso de estudo e pesquisa para a formação de professores (PEP-FP) para o ensino de equações polinomiais do primeiro grau com uma incógnita. O PEP-FP apoia-se em alguns elementos conceituais que fazem parte do dispositivo, tais como: o modelo epistemológico de referência (MER) e os tipos de organizações matemáticas (OM) que serão apresentados mais adiante. O dispositivo vem como uma proposta metodológica para formação de professores de educação básica, tendo como finalidade compreender a razão de ser das equações polinomiais do primeiro grau com uma incógnita e qual organização didática almejar para a formação inicial ou continuada desses profissionais. A pesquisa fundamenta-se na teoria antropológica do didático (TAD), mais especificamente nos constructos teórico-metodológicos de um PEP. Ademais, partimos da apresentação de um MER para o ensino de equações polinomiais do primeiro grau com uma incógnita. Esse MER é a alavanca para construção de organizações didáticas que viabilizem as atividades de estudo e pesquisa oriundas da questão proposta para a realização das atividades que conduziriam à resolução das questões derivadas. Por esta razão, propusemos um dispositivo didático (PEP-FP) por meio do qual o professor de ensino básico teria acesso a uma visão não apenas ampliada, mas regulada/ajustada pelos três princípios estruturantes do PEP e as dialéticas fundamentais de como estudar e ensinar equações polinomiais do primeiro grau com uma incógnita

    mTOR pathway in papillary thyroid carcinoma: Different contributions of mTORC1 and mTORC2 complexes for tumor behavior and SLC5A5 mRNA expression

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    The mammalian target of rapamycin (mTOR) pathway is overactivated in thyroid cancer (TC). We previously demonstrated that phospho-mTOR expression is associated with tumor aggressiveness, therapy resistance, and lower mRNA expression of SLC5A5 in papillary thyroid carcinoma (PTC), while phospho-S6 (mTORC1 effector) expression was associated with less aggressive clinicopathological features. The distinct behavior of the two markers led us to hypothesize that mTOR activation may be contributing to a preferential activation of the mTORC2 complex. To approach this question, we performed immunohistochemistry for phospho-AKT Ser473 (mTORC2 effector) in a series of 182 PTCs previously characterized for phospho-mTOR and phospho-S6 expression. We evaluated the impact of each mTOR complex on SLC5A5 mRNA expression by treating cell lines with RAD001 (mTORC1 blocker) and Torin2 (mTORC1 and mTORC2 blocker). Phospho-AKT Ser473 expression was positively correlated with phospho-mTOR expression. Nuclear expression of phospho-AKT Ser473 was significantly associated with the presence of distant metastases. Treatment of cell lines with RAD001 did not increase SLC5A5 mRNA levels, whereas Torin2 caused a ~6 fold increase in SLC5A5 mRNA expression in the TPC1 cell line. In PTC, phospho-mTOR activation may lead to the activation of the mTORC2 complex. Its downstream effector, phospho-AKT Ser473, may be implicated in distant metastization, therapy resistance, and downregulation of SLC5A5 mRNA expression.Acknowledgments: This study was supported by FCT (“Portuguese Foundation for Science and Technology”) through PhD grants to Catarina Tavares (SFRH/BD/87887/2012), Ana Pestana (SFRH/BD/110617/2015), and Rui Batista (SFRH/BD/111321/2015) and by a CNPq PhD grant (“National Counsel of Technological and Scientific Development”, Brazil), Science without Borders, Process n# 237322/2012-9 for Luciana Ferreira. Miguel Melo received a grant from Genzyme for the research project “Molecular biomarkers of prognosis and response to therapy in differentiated thyroid carcinomas”. Further funding was obtained from FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Inovação in the framework of the project "Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274), and by the project “Advancing cancer research: from basic acknowledgement to application”; NORTE-01-0145-FEDER-000029; “Projetos Estruturados de I&D&I, funded by Norte 2020-Programa Operacional Regional do Norte. This work was also financed by Sociedade Portuguesa de Endocrinologia Diabetes e Metabolismo through a grant “Prof. E. Limbert Sociedade Portuguesa de Endocrinologia Diabetes e Metabolismo/Sanofi-Genzyme in thyroid pathology”

    NIS expression in thyroid tumors, relation with prognosis clinicopathological and molecular features

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    Thyroid cancer therapy is based on surgery followed by radioiodine treatment. The incorporation of radioiodine by cancer cells is mediated by sodium iodide symporter (NIS) (codified by the SLC5A5 gene), that is functional only when targeted to the cell membrane. We aimed to evaluate if NIS expression in thyroid primary tumors would be helpful in predicting tumor behavior, response to therapy and prognosis. NIS expression was addressed by qPCR and immunohistochemistry. In order to validate our data, we also studied SLC5A5 expression on 378 primary papillary thyroid carcinomas from The Cancer Genome Atlas (TCGA) database. In our series, SLC5A5 expression was lower in carcinomas with vascular invasion and with extrathyroidal extension and in those harboring BRAFV600E mutation. Analysis of SLC5A5 expression from TCGA database confirmed our results. Furthermore, it showed that larger tumors, with locoregional recurrences and/or distant metastases or harboring RAS, BRAF and/or TERT promoter (TERTp) mutations presented significantly less SLC5A5 expression. Regarding immunohistochemistry, 12/211 of the cases demonstrated NIS in the membrane of tumor cells, those cases showed variable outcomes concerning therapy success, prognosis and all but one were wild type for BRAF, NRAS and TERTp mutations. SLC5A5 mRNA lower expression is associated with features of aggressiveness and with key genetic alterations involving BRAF, RAS and TERTp. Mutations in these genes seem to decrease protein expression and its targeting to the cell membrane. SLC5A5 mRNA expression is more informative than NIS immunohistochemical expression regarding tumor aggressiveness and prognostic features.This study was supported by FCT (‘Portuguese Foundation for Science and Technology’) through PhD grants to Catarina Tavares (SFRH/BD/87887/2012), Ana Pestana (SFRH/BD/110617/2015), Rui Batista (SFRH/BD/111321/2015) and by a CNPq PhD grant (‘National Counsel of Technological and Scientific Development’, Brazil), Science without Borders, Process n# 237322/2012-9 for Luciana Ferreira. Miguel Melo received a grant from Genzyme for the research project ‘Molecular biomarkers of prognosis and response to therapy in differentiated thyroid carcinomas’. Further funding was obtained from FEDER – Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 – Operational Program for Competitiveness and Internationalization (POCI), Portugal 2020, and by Portuguese funds through FCT – Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Inovação in the framework of the project ‘Institute for Research and Innovation in Health Sciences’ (POCI-01-0145-FEDER-007274) and by the project ‘Advancing cancer research: from basic knowledgement to application’; NORTE-01-0145-FEDER-000029; ‘Projetos Estruturados de I&D&I’, funded by Norte 2020-Programa Operacional Regional do Norte. This work was also financed by Sociedade Portuguesa de Endocrinologia Diabetes e Metabolismo through a grant ‘Prof. E Limbert Sociedade Portuguesa de Endocrinologia Diabetes e Metabolismo/Sanofi-Genzyme in thyroid pathology’

    Top quark forward-backward asymmetry in R-parity violating supersymmetry

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    The interaction of bottom squark-mediated top quark pair production, occurring in the R-parity violating minimal supersymmetric standard model (MSSM), is proposed as an explanation of the anomalously large ttˉt\bar{t} forward-backward asymmetry (FBA) observed at the Tevatron. We find that this model can give a good fit to top quark data, both the inclusive and invariant mass-dependent asymmetries, while remaining consistent (at the 2-σ\sigma level) with the total and differential production cross-sections. The scenario is challenged by strong constraints from atomic parity violation (APV), but we point out an extra diagram for the effective down quark-Z vertex, involving the same coupling constant as required for the FBA, which tends to weaken the APV constraint, and which can nullify it for reasonable values of the top squark masses and mixing angle. Large contributions to flavor-changing neutral currents can be avoided if only the third generation of sparticles is light.Comment: 24 pages, 7 figures. v3: included LHC top production cross section data; model still consistent at 2 sigma leve

    Documento de consenso sobre codificação de exames de ressonância magnética cardíaca em Portugal

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    One of the obstacles to more frequent and appropriate use of cardiac magnetic resonance (CMR) in Portugal has been the lack of specific codes that accurately describe these examinations as they are currently performed. In this consensus document, recommendations are made for updating and standardizing CMR codes in Portugal. Guidance on which techniques and codes should be used in the most common clinical scenarios is also provided

    Collagen Type IV-Related Nephropathies in Portugal: Pathogenic COL4A5 Mutations and Clinical Characterization of 22 Families

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    Alport syndrome (AS) is caused by pathogenic mutations in the genes encoding α3, α4 or α5 chains of collagen IV (COL4A3/COL4A4/COL4A5), resulting in hematuria, chronic renal failure (CRF), sensorineural hearing loss (SNHL) and ocular abnormalities. Mutations in the X-linked COL4A5 gene have been identified in 85% of the families (XLAS). In this study, 22 of 60 probands (37%) of unrelated Portuguese families, with clinical diagnosis of AS and no evidence of autosomal inheritance, had pathogenic COL4A5 mutations detected by Sanger sequencing and/or multiplex-ligation probe amplification, of which 12 (57%) are novel. Males had more severe and earlier renal and extrarenal complications, but microscopic hematuria was a constant finding irrespective of gender. Nonsense and splice site mutations, as well as small and large deletions, were associated with younger age of onset of SNHL in males, and with higher risk of CRF and SNHL in females. Pathogenic COL4A3 or COL4A4 mutations were subsequently identified in more than half of the families without a pathogenic mutation in COL4A5. The lower than expected prevalence of XLAS in Portuguese families warrants the use of next-generation sequencing for simultaneous COL4A3/COL4A4/COL4A5 analysis, as first-tier approach to the genetic diagnosis of collagen type IV-related nephropathies.info:eu-repo/semantics/publishedVersio
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