133 research outputs found
O movimento paranaense de matemática moderna: o papel do NEDEM
Disponível em: http://www2.pucpr.br/reol/pb/index.php/dialogo?dd1=581&dd99=view&dd98=pbNo final da década de 50, o impacto produzido pelo lançamento do Sputnik preocupou não somente o governo americano, mas também educadores de várias partes do mundo envolvidos com a formação científica da população. O êxito científico e tecnológico alcançado pelos russos ampliou a preocupação de vários países com a educação matemática oferecida à população, gerando um movimento internacional de reformulação do ensino de Matemática, conhecido como Movimento da Matemática Moderna, uma tentativa que nos anos 60 e 70 procurava superar o ensino tradicional que até a década de 50 privilegiava a matemática clássica, o modelo euclidiano, a visão platônica. No Brasil, esse movimento foi liderado pelo grupo paulista – GEEM - coordenado por Oswaldo Sangiorgi, incentivando a criação de grupos de estudos em vários estados com vistas à modernização da Matemática ensinada no ensino primário e ginasial (hoje Ensino Fundamental). No Paraná, o disseminador do Movimento da Matemática Moderna foi o NEDEM – Núcleo de Estudos e Difusão do Ensino da Matemática – criado e coordenado por Osny Antonio Dacol, diretor do Colégio Estadual do Paraná. Trabalhando inicialmente com classes experimentais no maior colégio do estado, o NEDEM elaborou sua proposta de Matemática Moderna que, posteriormente, foi publicada em duas coleções de livros didáticos que passaram a ser adotadas pelas escolas paranaenses durante mais de duas décadas. Tais iniciativas marcaram significativamente o ensino de Matemática no Paraná. A repercussão do movimento teve seu auge na década de 60 e no final de 1970 e mesmo com a extinção do grupo, as sementes plantadas pelos integrantes do NEDEM deixaram marcas na história da educação matemática paranaense, especialmente pelo intenso e democrático trabalho de difusão do movimento no ensino público do Paraná
Effects of hyperleptinemia in rat saliva composition, histology and ultrastructure of the major salivary glands
OBJECTIVE:
To study the effect of the satiety hormone, leptin, in saliva proteome and salivary gland histology and ultrastructure.
DESIGN:
Increases in blood leptin levels were induced through mini-pump infusion in male Wistar rats, during a period of 7 days. Saliva was collected before and at the end of the experimental period, for proteomic analysis, and major salivary glands were collected, at the end, for biochemical, histological and ultrastructural analysis.
RESULTS:
Immunohistochemistry revealed the presence of leptin receptors in major salivary glands. Salivary amylase levels and enzymatic activity were decreased in saliva, whereas the enzymatic activity of this protein was increased in the cytosol of parotid gland cells. Transmission electron microscopy allowed the observation of high number of electron-dense granules in cytosol of parotid acinar cells, from leptin treated animals.
CONCLUSIONS:
Increased levels of plasmatic leptin result in changes in saliva composition and salivary glands function. To our knowledge, this is the first study providing evidences for a potential role of leptin in salivary gland secretion and saliva composition. An understanding of how appetite/satiety factors influence saliva composition and how this composition influences food processing in mouth may be relevant in understanding ingestive behaviour.FC
Estimation of HIV incidence in two Brazilian municipalities, 2013
OBJECTIVE To estimate HIV incidence in two Brazilian municipalities, Recife and Curitiba, in the year of 2013. METHODS The method for estimating incidence was based on primary information, resulting from the Lag-Avidity laboratory test for detection of recent HIV infections, applied in a sample of the cases diagnosed in the two cities in 2013. For the estimation of the HIV incidence for the total population of the cities, the recent infections detected in the research were annualized and weighted by the inverse of the probability of HIV testing in 2013 among the infected and not diagnosed cases. After estimating HIV incidence for the total population, the incidence rates were estimated by sex, age group, and exposure category. RESULTS In Recife, 902 individuals aged 13 years and older were diagnosed with HIV infection. From these, 528 were included in the study, and the estimated proportion of recent infections was 13.1%. In Curitiba, 1,013 people aged 13 years and older were diagnosed, 497 participated in the study, and the proportion of recent infections was 10.5%. In Recife, the estimated incidence rate was 53.1/100,000 inhabitants of 13 years and older, while in Curitiba, it was 41.1/100,000, with male-to-female ratio of 3.5 and 2.4, respectively. We observed high rates of HIV incidence among men who have sex with men, of 1.47% in Recife and 0.92% in Curitiba. CONCLUSIONS The results obtained in the two cities showed that the group of men who have sex with men are disproportionately subject to a greater risk of new infections, and indicate that strategies to control the spread of the epidemic in this population subgroup are essential and urgent.OBJETIVO Estimar a incidência de HIV em dois municípios brasileiros, Recife e Curitiba, no ano de 2013. MÉTODOS O método de estimação da incidência foi baseado em informações primárias, resultantes do ensaio laboratorial Lag-Avidity para detecção de infecções recentes do HIV, aplicado em uma amostra dos casos diagnosticados nas duas cidades em 2013. Para a estimação da incidência de HIV para a população total das cidades, as infecções recentes detectadas na pesquisa foram anualizadas e ponderadas pelo inverso da probabilidade de teste de HIV no ano de 2013 entre os casos infectados e não diagnosticados. Após a estimação da incidência de HIV para a população total, foram estimadas as taxas de incidência por sexo, faixa de idade e categoria de exposição. RESULTADOS Em Recife, foram diagnosticados 902 indivíduos de 13 anos e mais com infecção de HIV. Desses, 528 foram incluídos no estudo, e a proporção estimada de infecções recentes foi de 13,1%. Em Curitiba, foram diagnosticadas 1.013 pessoas de 13 anos e mais, 497 participaram do estudo, e a proporção de infecções recentes foi de 10,5%. Em Recife, a taxa de incidência estimada foi de 53,1 por 100 mil habitantes de 13 anos e mais, enquanto em Curitiba, de 41,1 por 100 mil, com razão do sexo masculino para o feminino de 3,5 e 2,4, respectivamente. Foram evidenciadas elevadas taxas de incidência de HIV entre homens que fazem sexo com homens, de 1,47% em Recife e 0,92% em Curitiba. CONCLUSÕES Os resultados obtidos nas duas cidades mostraram que o grupo dos homens que fazem sexo com homens está desproporcionalmente sujeito ao maior risco de novas infecções, e indicam que estratégias para controle da disseminação da epidemia nesse subgrupo populacional são essenciais e urgentes
Population Prevalence of Trachoma in Nine Rural Non-Indigenous Evaluation Units of Brazil.
Purpose: To assess the contemporary prevalence of trachoma in Brazil's non-indigenous population, surveys of those thought to be at greatest risk of disease were conducted.Methods: Rural census tracts of non-indigenous population from nine mesoregions were selected to compose the survey evaluation units (EUs) by considering previously endemic municipalities at greatest risk of trachoma. In each of the nine EUs, we conducted a population-based prevalence survey. Every resident of selected households aged ≥1 year was examined for trachomatous inflammation - follicular (TF) and trachomatous trichiasis (TT). Additionally, data were collected on household-level access to water, sanitation, hygiene (WASH) and education.Results: A total of 27,962 individuals were examined across nine EUs. The age-adjusted TF prevalence in 1-9-year-olds was 99% of surveyed children.Conclusions: The prevalence of TF was well below the target for elimination as a public health problem in all EUs. Because EUs surveyed were selected to represent the highest-risk non-indigenous areas of the country, TF prevalence is unlikely to be ≥5% in non-indigenous populations elsewhere. In one EU, the prevalence of TT was above the target threshold for elimination. Further investigation and possibly improvement in TT surgical provision are required in that EU
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Rarity of monodominance in hyperdiverse Amazonian forests.
Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors
SARS-CoV-2 introductions and early dynamics of the epidemic in Portugal
Genomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by
the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration
with more than 50 laboratories distributed nationwide.
Methods By applying recent phylodynamic models that allow integration of individual-based
travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal.
Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from
European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland),
which were consistent with the countries with the highest connectivity with Portugal.
Although most introductions were estimated to have occurred during early March 2020, it is
likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the
first cases were confirmed.
Conclusions Here we conclude that the earlier implementation of measures could have
minimized the number of introductions and subsequent virus expansion in Portugal. This
study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.We gratefully acknowledge to Sara Hill and Nuno Faria (University of Oxford) and
Joshua Quick and Nick Loman (University of Birmingham) for kindly providing us with
the initial sets of Artic Network primers for NGS; Rafael Mamede (MRamirez team,
IMM, Lisbon) for developing and sharing a bioinformatics script for sequence curation
(https://github.com/rfm-targa/BioinfUtils); Philippe Lemey (KU Leuven) for providing
guidance on the implementation of the phylodynamic models; Joshua L. Cherry
(National Center for Biotechnology Information, National Library of Medicine, National
Institutes of Health) for providing guidance with the subsampling strategies; and all
authors, originating and submitting laboratories who have contributed genome data on
GISAID (https://www.gisaid.org/) on which part of this research is based. The opinions
expressed in this article are those of the authors and do not reflect the view of the
National Institutes of Health, the Department of Health and Human Services, or the
United States government. This study is co-funded by Fundação para a Ciência e Tecnologia
and Agência de Investigação Clínica e Inovação Biomédica (234_596874175) on
behalf of the Research 4 COVID-19 call. Some infrastructural resources used in this study
come from the GenomePT project (POCI-01-0145-FEDER-022184), supported by
COMPETE 2020 - Operational Programme for Competitiveness and Internationalisation
(POCI), Lisboa Portugal Regional Operational Programme (Lisboa2020), Algarve Portugal
Regional Operational Programme (CRESC Algarve2020), under the PORTUGAL
2020 Partnership Agreement, through the European Regional Development Fund
(ERDF), and by Fundação para a Ciência e a Tecnologia (FCT).info:eu-repo/semantics/publishedVersio
Pervasive gaps in Amazonian ecological research
Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4
While the increasing availability of global databases on ecological communities has advanced our knowledge
of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In
the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of
Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus
crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced
environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian
Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by
2050. This means that unless we take immediate action, we will not be able to establish their current status,
much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio
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