601 research outputs found
O peculiar olhar sobre os acontecimentos do Jornal Português da Argentina
O artigo problematiza se o Jornal Português, único periódico da comunidade portuguesa residente na Argentina, pode constituir um elemento significativo na (re)construção e (re)negociação da identidade portuguesa desta comunidade. Uma identidade que consideramos ser imaginada e, sobretudo, construída pelos próprios imigrantes, estruturando-se em torno «da saudade e da lembrança de uma vida passada»: a vida em Portugal, um horizonte longínquo, muito embora presente no seu dia-a-dia.
Esta análise é parte do meu trabalho de doutoramento sobre a comunidade portuguesa residente no partido de Escobar, na Província de Buenos Aires (República Argentina). Partindo de um exercício descritivo de enquadramento, este trabalho tem como objectivos gerais observar e discutir o papel dos media na gestão quotidiana da identidade colectiva desta população migrante. No decorrer deste exercício observou-se que uma grande percentagem dos inquiridos recebe todos os meses pelo correio a edição do Jornal
Português, considerando-o um elo de ligação, primeiro à terra e mais tarde a
Portugal.
Para finalizar, diremos que o Jornal Português, criado pelos membros da comunidade portuguesa, aparece como uma das estratégias de visibilidade e ligação desta comunidade
Bats of the state of Minas Gerais, southeastern Brasil
Minas Gerais (MG) é o maior estado da região sudeste e sua localização em área de transição entre a faixa super úmida da costa e os ecossistemas mais áridos do centro-oeste brasileiro propicia a ocorrência de um rico mosaico de biomas e ecossistemas, incluindo o Cerrado, a Caatinga, a Mata Atlântica e áreas cársticas. Embora se saiba que a mastofauna de Minas Gerais é rica em espécies, não há uma lista de espécies de morcegos publicada, sendo esta a primeira compilação da fauna de quirópteros de MG. São aqui reunidos dados originais de inventários realizados independentemente pelos autores, informações da literatura e levantamento de espécimes depositados em várias coleções. Os resultados indicam a ocorrência de 77 espécies distribuídas em sete famílias em Minas Gerais, o que coloca o estado como o mais rico do sudeste brasileiro em número de espécies de morcegos. Essa riqueza surpreende também, devido ao fato constatado da escassez de dados disponíveis, conforme detectado no presente estudo. Grandes áreas do estado permanecem pouco conhecidas ou completamente desconhecidas em termos de sua quiropterofauna, incluindo ecossistemas frágeis associados à Caatinga, ao Cerrado e à Mata Atlântica, como os campos rupestres e áreas cársticas e não há sequer um estudo de longa duração. As coleções estudadas têm pouca representatividade em termos de espécimes oriundas do estado de Minas Gerais e são raras as séries sistemáticas oriundas de coletas no estado.Minas Gerais is the largest state in the Southeastern of Brazil, and its location in the transition between the humid coastal Atlantic Forest and the drier Western and central Brazilian countryside allows the occurrence of a rich mosaic of biomes and ecosystems that includes the Cerrado, the Caatinga, the Atlantic Forest, and karstic environments. This work is the first comprehensive compilation of the bat fauna of Minas Gerais state, Southeastern Brazil, including original data from surveys conducted independently by the authors, and published information documented with data from several museum collections. Although large areas of MG remains unsampled, unknown and/or unprotected, long term studies are virtually inexistent, and systematic inventories have not been documented to date, our results reveal high bat species richness for the state, with 77 species distributed in seven families. This indicates that MG has more bat species recorded than other Southeastern Brazilian states, a result that contrasts with the noticeable paucity of data for the state. The bat diverstity kept in museums does not mirror the actual bat diversity of MG, which thus urges to be properly acessed. Additionally, the collections examined were poorly represented in specimens from Minas Gerais and systematic series are rare
Multifunctional bacterial cellulose-chitosan tape: an innovative substitute for PVC
Synthetic polymers, generically named plastics, are manufactured from non-renewable sources, such as fossil fuels [1]. In 2020, 367 million metric tons of plastic were produced worldwide, and, only in 2018, global plastic waste volume reached 342.6 million metric tons [2,3]. One of the most used plastics is polyvinyl chloride (PVC), which is not environmentally friendly. The goal of this study was to achieve an eco-friendly substitute for PVC tapes while mimicking their properties and applications. In this way, bacterial cellulose (BC) and chitosan (CH) tapes in different concentrations, 1% and 2%, were developed. Mechanical properties, thickness, bonds between BC and CH and degradation tests were assessed in water and under different temperatures. Mechanical testing showed that the combination of the two polymers resulted in better mechanical performances when compared to BC tape (8.52 ± 1.11 MPa); this may be related to the stronger chemical bonds created between the BC and CH. In addition, BC–CH at 1% revealed closer values of strength compared to PVC tapes (703.19 ± 16.18 MPa and 516.92 ± 22.0 MPa, respectively). Moreover, with the present study we were able to conclude that the incorporation of CH increases tape porosity. Interestingly, higher porosities (BC and CH at 2%) resulted in better mechanical properties upon tensile testing (1344 ± 52.87 MPa). Upon contact with water, the BC–CH mixture at 1% proved to be more resistant and not mechanically affected over time, like PCV tape. Thermally, both tapes with CH revealed to be more resistant than the PVC tape. However, the BC–CH tape at 1% was the most stable over time at all temperatures tested. This preliminary study opens new possibilities to the use of these tapes in sport areas, packaging and pharmaceutical or biomedical fields.This research was funded by the Fundação para a Ciência e a Tecnologia FCT/MCTES
(PIDDAC) and Centro2020 through the following Projects: UIDB/04044/2020; UIDP/04044/2020;
Associate Laboratory ARISE LA/P/0112/2020; PAMI-ROTEIRO/0328/2013 (Nº 022158).info:eu-repo/semantics/publishedVersio
Cross-cultural adaptation of Hypertension Knowledge Test into European Portuguese
We aim to validate a European-Portuguese version of the Hypertension Knowledge Test (HKT) questionnaire and examine its factorial structure with a confirmatory factor analysis (CFA). A process of translation and back-translation was performed. A cross-sectional study was developed in which all adult patients taking at least one antihypertensive drug were invited to participate. Data on personal and family history were collected, and the HKT, Strelec, and the Batalla questionnaires were administered. We enrolled 304 patients with a mean age of 68.12±10.83 years. The mean score of HKT was 15.33±2.79. CFA indicated that the construct being tested was unidimensional, and Cronbach’s alpha (α=0.65) showed that the instrument had an acceptable internal consistency. When evaluating concurrent validity, HKT was significantly correlated with the Batalla and Strelec scores. Thus, the Portuguese version of HKT (HKT-pt-PT) can be used either in research or in clinical practice. With this version, a potential standard exists to evaluate knowledge about hypertension, which could avoid the practice of using non-validated questionnaires in Portugal and allow the cross-sectional and longitudinal comparability of studies
Sarcoplasmic reticulum calcium ATPase is inhibited by organic vanadium coordination compounds: pyridine-2,6-dicarboxylatodioxovanadium(V), BMOV, and an amavadine analogue
Inorg Chem. 2008 Jul 7;47(13):5677-84. doi: 10.1021/ic702405dThe general affinity of the sarcoplasmic reticulum (SR) Ca (2+)-ATPase was examined for three different classes of vanadium coordination complexes including a vanadium(V) compound, pyridine-2,6-dicarboxylatodioxovanadium(V) (PDC-V(V)), and two vanadium(IV) compounds, bis(maltolato)oxovanadium(IV) (BMOV), and an analogue of amavadine, bis( N-hydroxylamidoiminodiacetato)vanadium(IV) (HAIDA-V(IV)). The ability of vanadate to act either as a phosphate analogue or as a transition-state analogue with enzymes' catalysis phosphoryl group transfer suggests that vanadium coordination compounds may reveal mechanistic preferences in these classes of enzymes. Two of these compounds investigated, PDC-V(V) and BMOV, were hydrolytically and oxidatively reactive at neutral pH, and one, HAIDA-V(IV), does not hydrolyze, oxidize, or otherwise decompose to a measurable extent during the enzyme assay. The SR Ca (2+)-ATPase was inhibited by all three of these complexes. The relative order of inhibition was PDC-V(V) > BMOV > vanadate > HAIDA-V(IV), and the IC 50 values were 25, 40, 80, and 325 microM, respectively. Because the observed inhibition is more potent for PDC-V(V) and BMOV than that of oxovanadates, the inhibition cannot be explained by oxovanadate formation during enzyme assays. Furthermore, the hydrolytically and redox stable amavadine analogue HAIDA-V(IV) inhibited the Ca (2+)-ATPase less than oxovanadates. To gauge the importance of the lipid environment, studies of oxidized BMOV in microemulsions were performed and showed that this system remained in the aqueous pool even though PDC-V(V) is able to penetrate lipid interfaces. These findings suggest that the hydrolytic properties of these complexes may be important in the inhibition of the calcium pump. Our results show that two simple coordination complexes with known insulin enhancing effects can invoke a response in calcium homeostasis and the regulation of muscle contraction through the SR Ca (2+)-ATPase
A multidisciplinary approach for the management of hypodontia: case report
Hypodontia is the congenital absence of one or more teeth and may affect permanent teeth. Several options are indicated to treat hypodontia, including the maintenance of primary teeth or space redistribution for restorative treatment with partial adhesive bridges, tooth transplantation, and implants. However, a multidisciplinary approach is the most important requirement for the ideal treatment of hypodontia. This paper describes a multidisciplinary treatment plan for congenitally missing permanent mandibular second premolars involving orthodontics, implantology and prosthodontic specialties
Bayesian cross-validation of geostatistical models
The problem of validating or criticizing models for georeferenced data is challenging as much as conclusions may be sensitive to the partition of data into training and validation cases. This is an obvious issue related to the basic validation scheme which selects a subset of the data to leave out of estimation and to make predictions with an assumed model. In this setup, only a few out-of-sample locations are usually selected to validate the model. On the other hand, the cross-validation approach, which considers several possible configurations of data divided into training and validation observations, is an appealing alternative, but it could be computationally demanding as the estimation of parameters usually requires computationally intensive methods. The purpose of this work is to use cross-validation techniques to choose between competing models and to assess the goodness of fit of spatial models in different regions of the spatial domain. We consider the sampling design for selecting the training and validation sets by assigning a probability distribution to the possible data partitions. To deal with the computational burden of cross-validation, we estimate discrepancy functions in a computationally efficient manner based on the importance weighting of posterior samples. Furthermore, we propose a stratified cross-validation scheme to take into account spatial heterogeneity, reducing the total variance of estimated predictive discrepancy measures. We also illustrate the advantages of our proposal with simulated examples of homogeneous and inhomogeneous spatial processes and with an application to rainfall dataset in Rio de Janeiro.
The purpose of this work is to use cross-validation techniques to choose between competing models and to assess the goodness of fit of spatial models in different regions of the spatial domain. We consider the sampling design for selecting the training and validation sets by assigning a probability distribution to the possible data partitions. To deal with the computational burden of cross-validation, we estimate discrepancy functions in a computationally efficient manner based on the importance weighting of posterior samples. Furthermore, we propose a stratified cross-validation scheme to
take into account spatial heterogeneity, reducing the total variance of estimated predictive discrepancy measures. We also illustrate the advantages of our proposal with simulated examples of homogeneous and inhomogeneous spatial processes and with an application to rainfall dataset in Rio de Janeiro
Assessment of neural networks training strategies for histomorphometric analysis of synchrotron radiation medical images
Abstract Micro-computed tomography (μCT) obtained by synchrotron radiation (SR) enables magnified images with a high space resolution that might be used as a non-invasive and non-destructive technique for the quantitative analysis of medical images, in particular the histomorphometry (HMM) of bony mass. In the preprocessing of such images, conventional operations such as binarization and morphological filtering are used before calculating the stereological parameters related, for example, to the trabecular bone microarchitecture. However, there is no standardization of methods for HMM based on μCT images, especially the ones obtained with SR X-ray. Notwithstanding the several uses of artificial neural networks (ANNs) in medical imaging, their application to the HMM of SR-μCT medical images is still incipient, despite the potential of both techniques. The contribution of this paper is the assessment and comparison of well-known training algorithms as well as the proposal of training strategies (combinations of training algorithms, sub-image kernel and symmetry information) for feed-forward ANNs in the task of bone pixels recognition in SR-μCT medical images. For a quantitative comparison, the results of a cross validation and a statistical analysis of the results for 36 training strategies are presented. The ANNs demonstrated both very low mean square errors in the validation, and good quality segmentation of the image of interest for application to HMM in SR-μCT medical images
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