490 research outputs found

    Accidental Father-to-Son HIV-1 Transmission During the Seroconversion Period

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    A 4-year-old child born to an HIV-1 seronegative mother was diagnosed with HIV-1, the main risk factor being transmission from the child's father who was seroconverting at the time of the child's birth. In the context of a forensic investigation, we aimed to identify the source of infection of the child and date of the transmission event. Samples were collected from the father and child at two time points about 4 years after the child's birth. Partial segments of three HIV-1 genes (gag, pol, and env) were sequenced and maximum likelihood (ML) and Bayesian methods were used to determine direction and estimate date of transmission. Neutralizing antibodies were determined using a single cycle assay. Bayesian trees displayed a paraphyletic-monophyletic topology in all three genomic regions, with the father's host label at the root, which is consistent with father-to-son transmission. ML trees found similar topologies in gag and pol and a monophyletic-monophyletic topology in env. Analysis of the time of the most recent common ancestor of each HIV-1 gene population indicated that the child was infected shortly after the father. Consistent with the infection history, both father and son developed broad and potent HIV-specific neutralizing antibody responses. In conclusion, the direction of transmission implicated the father as the source of transmission. Transmission occurred during the seroconversion period when the father was unaware of the infection and was likely accidental. This case shows how genetic, phylogenetic, and serological data can contribute for the forensic investigation of HIV transmission.info:eu-repo/semantics/publishedVersio

    Portuguese Adaptation of Students Engagement in Schools International Scale (SESIS)

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    The importance of student’s engagement has been recently pointed out in research. However, there has been a lack of engagement assessment instrument, pertaining psychometric qualities. Objective: This paper presents the Portuguese adaptation of the “Student’s Engagement in School International Scale” (SESIS), drawn up from a12 countries international study (Lam et al., 2012; Lam et al., in press). Method: Psychometric properties of this scale were examined with data from 685 students from different grades (6th, 7th, 9th and 10th), from both sexes, and different regions of the country. Results: Factorial analysis of the results, with varimax rotation, lead to three different factors which explain 50.88% of the variance. The scale integrates the original 33 items, and cognitive, affective and behavioural dimensions. For the external validity study, the relationship between student’s engagement in school results and other school variables — academic performance, self-concept — was considered, and significant relations were observed, as expected. Conclusion: The data presented highlights the qualities of SESIS, as well as its usefulness for research purposes. Suggestion: It is suggested the investigation of the extension of SESIS’s three-dimensionality, in future studiesKeywords: Innovation, technology, research projects, etc. [Arial 10-point, justified alignment]

    Scour around marine foundations in layered sediments: a mathematical modelling approach

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    In order to improve the understanding of scour processes in layered conditions for offshore foundations, a laboratory study was conducted regarding equilibrium scour depth vs. time curve and its adjustment to hyperbolic and exponential/linear combined functions. The present paper provides a mathematical study describing a set of scour tests in order to clarify the scour depth evolution for complex, non-cohesive soil configurations

    Evaluation of an in-house molecular HIV-1 test to assess mother-to-child HIV-1 transmission in Angola (the APEHC cohort)

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    Poster presented at the 17th Annual International Meeting of the Institute of Human Virology. Baltimore, 27-30 September 2015"Mother-to-child-transmission (MTCT) rate has decreased sharply in recent years in most of the sub-Saharan Africa, however 220,000 children acquired HIV-1 in 2014. PCR detection of proviral DNA is the most sensitive method for early infant diagnosis (EID) of HIV-1 infection. Commercial kits are available but they have poor sensitivity with divergent non-B subtypes and high costs (≈30€ per test) which limit their use in resource-limited settings. The HIV-1 epidemic in Angola is driven by highly divergent strains of all group M subtypes, except B, as well as multiple recombinant forms (CRFs and URFs) making EID a challenge in this setting. The aim of this study was to develop and validate a qualitative, inexpensive and sensitive “inhouse” HIV-1 EID assay on heel prick dried blood spots (DBS) from infants of the Hospital da Divina Providência (HDP) in Luanda, Angola and determine the current HIV-1 MTCT rate in the Angolan PErinatal HIV Cohort (APEHC)."Fundação para a Ciência e a Tecnologia - Portugal ; European Unio

    Brief review on the limit state function of dynamic scour protections

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    Offshore foundations, namely for offshore wind, wave and tidal applications, often require the use of scour protections. Rip-rap scour protections are an important element of the foundation to ensure that the natural frequency stays within the design limits. Scour protection design still presents a remarkable empirical nature, which typically leads to uncertainty on their behaviour under extreme met-ocean conditions. Therefore, reliability assessment of scour protections has been seen as a possibility to account for design uncertainty and to optimise the scour protections. However, the definition of a suitable limit state function is still a matter of research focus, namely, regarding the proper definition of the acceptable damage level for dynamic scour protections. This research provides a brief review on the recent studies related to both the limit state function and the calculation of damage numbers through bathymetric data. A discussion is raised on how the methodologies for calculating the damage number may influence the limit state function and a theoretical example is given to assess the effects on the probability of failure. Results have shown that the acceptable damage number requires a clearer definition, which should be based on the number of layers of rock material and the area of filter exposure. In addition, this research highlights the need for alternative ways to assess damage

    Perfis proteicos e desempenho fisiológico de sementes de café submetidas a diferentes métodos de processamento e secagem.

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    O objetivo deste trabalho foi avaliar os perfis proteicos e o desempenho fisiológico de sementes de café submetidas a diferentes métodos de processamento e secagem. Foram avaliados os processamentos por via seca e úmida, e as secagens natural, em terreiro, e artificial a 60ºC, ou a 60ºC até 30% de umidade e 40ºC até teor final de 11% (base úmida). Após serem processadas e secadas, as sementes foram avaliadas quanto ao desempenho fisiológico e submetidas a análises bioquímicas, por meio da eletroforese de proteínas resistentes ao calor LEA (?late embryogenesis abundant?) e das enzimas superóxido dismutase, catalase, peroxidase, esterase, polifenoloxidase, isocitrato desidrogenase, álcool desidrogenase e malato desidrogenase. O perfil proteico de sementes de café é afetado pelo método de processamento e de secagem. Os cafés processados por via úmida apresentam maior tolerância à secagem ? revelada pela maior atividade de enzimas antioxidativas e pelo melhor desempenho fisiológico ? do que os processados por via seca. A atividade de proteínas resistentes ao calor e de enzimas antioxidantes é variável promissora para diferenciar a qualidade dos cafés submetidos a diferentes manejos pós‑colheita

    Influência do atrito das defensas no comportamento de um navio amarrado para diferentes níveis de pré-tensão nos traveses

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    Nesta comunicação analisa-se a influência do coeficiente de atrito na interface do casco do navio com as defensas, no comportamento de um navio petroleiro amarrado, para duas condições de pré-tensão nos cabos de amarração. A análise é efectuada com base nos resultados de testes em modelo físico do comportamento de um navio amarrado no Posto "A" do Terminal de Petroleiros do Porto de Leixões. Esses testes foram realizados com dois modelos físicos construídos à escala geométrica 1/100. O primeiro corresponde a uma reprodução simplificada do Posto "A" e área envolvente, com o modelo do navio a ser ensaiado, exclusivamente, para ondas de vante. O segundo procura reproduzir as características do protótipo com maior rigor, e inclui o quebramar Norte (ou exterior), o molhe Sul, o antigo quebramar Norte (estrutura centenária), e uma extensão significativa da praia de Matosinhos

    Monitoramento da murcha do abacaxizeiro associada à cochonilha Dysmicoccus brevipes em áreas de sistema de produção integrada no Estado do Tocantins - ciclo 2010.

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    No Brasil, cultiva-se o abacaxizeiro, Ananas comosus (L) na maioria das regiões ,sendo a 'Pérola' a cultivar mais plantada. Apesar de seu aspecto rústico, essa bromeliácea, em uma produção comercial, exige tratos culturais e fitossanitários rigorosos, para evitar problemas como a murcha que está associada à cochonilha Dysmicoccus brevipes Cockerell (1893) (Hemiptera: Pseudococcidae), cujas perdas na produção, em cultivares suscetíveis, podem ultrapassar os 80% (SANCHES, 2005). O mercado interno é ainda o mais visado pelos produtores de abacaxi, sendo a aquisição ou venda de mudas entre produtores uma prática muito comum que, propicia a dispersão desse inseto de uma propriedade para outra ou de uma região para outra. O Sistema de Produção Integrada de Abacaxi é uma prática de apoio aos produtores para atender as exigências crescentes do mercado consumidor quanto à produção de alimentos seguros. Esse sistema é baseado nas boas práticas agrícolas traduzindo em valorização do ser humano, conservação do meio ambiente (solo e água), melhoria da qualidade de vida dos produtores rurais, respeito à legislação trabalhista e segurança do trabalhador.bitstream/item/31028/1/documentos-193ID27590.pd
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