145 research outputs found

    The community of science and technology sociologists in Portugal

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    A Secção Temática Conhecimento, Ciência e Tecnologia da Associação Portuguesa de Sociologia foi constituída em 2010. 8 anos volvidos, com 4 congressos e 3 conferências realizadas, que balanço fazer da ST CCT? Esta comunicação tem por objetivo fazer um mapeamento de pessoas, instituições e temas de investigação. Pretende-se conhecer como a comunidade de sociólogos da ciência tem evoluído e que colaborações tece entre si, que zonas de fronteiras com outros ramos da sociologia e outras disciplinas científicas se estabelecem, que questões de investigação emergem ou desaparecem, que papel desempenha a Secção na formação de jovens investigadores e na integração de sociólogos fora da academia. Este balanço afigura-se-nos como um contributo para a reflexão sobre novas estratégias e caminhos a serem trilhados. Mas também poderá servir para conhecer melhor a sociologia da ciência portuguesa e contextualizá-la no panorama dos estudos de ciência em Portugal, bem como no âmbito europeu e internacional mais lato.info:eu-repo/semantics/publishedVersio

    Glycaemia Fluctuations Improvement in Old-Age Prediabetic Subjects Consuming a Quinoa-Based Diet: A Pilot Study

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    This study aimed to observe if quinoa could produce a benefit on postprandial glycemia that would result in less progression to type 2 diabetes (T2D). A cross-over design pilot clinical study with a nutritional intervention for 8 weeks was performed: 4 weeks on a regular diet (RD) and 4 weeks on a quinoa diet (QD). Nine subjects aged ?65 years with prediabetes were monitored during the first 4 weeks of RD with daily dietary records and FreeStyle Libre®. Subsequently, participants started the QD, where quinoa and 100% quinoa-based products replaced foods rich in complex carbohydrates that they had consumed in the first 4 weeks of RD. The glycemic measurements recorded by the sensors were considered as functions of time, and the effects of nutrients consumed at the intended time period were analyzed by means of a function-on-scalar regression (fosr) model. With QD participants, decreased body weight (-1.6 kg, p = 0.008), BMI (-0.6 kg/m2p = 0.004) and waist circumference (-1.5 cm, p = 0.015) were observed. Nutrients intake changed during QD, namely, decreased carbohydrates (p = 0.004) and increased lipids (p = 0.004) and some amino acids (p < 0.05). The fosr model showed a reduction in postprandial glycemia in QD despite intrapersonal differences thanks to the joint action of different nutrients and the suppression of others consumed on a regular diet. We conclude that in an old age and high T2D-risk population, a diet rich in quinoa reduces postprandial glycemia and could be a promising T2D-preventive strategy

    Participação associativa dos investigadores científicos em Portugal

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    A participação associativa dos portugueses é geralmente considerada baixa, apesar da profusão de associações. Este artigo dá conta das práticas e motivações associativas de um grupo particular, os investigadores científicos. Com base num inquérito por questionário sobre a sua participação em associações científicas nacionais e internacionais, explora-se questões como a pertença ou não pertença, os perfis motivacionais para a adesão e as formas de envolvimento na vida destas organizações, procurando aferir a sua relação com as variáveis sociodemográficas relevadas

    Representing complex data using localized principal components with application to astronomical data

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    Often the relation between the variables constituting a multivariate data space might be characterized by one or more of the terms: ``nonlinear'', ``branched'', ``disconnected'', ``bended'', ``curved'', ``heterogeneous'', or, more general, ``complex''. In these cases, simple principal component analysis (PCA) as a tool for dimension reduction can fail badly. Of the many alternative approaches proposed so far, local approximations of PCA are among the most promising. This paper will give a short review of localized versions of PCA, focusing on local principal curves and local partitioning algorithms. Furthermore we discuss projections other than the local principal components. When performing local dimension reduction for regression or classification problems it is important to focus not only on the manifold structure of the covariates, but also on the response variable(s). Local principal components only achieve the former, whereas localized regression approaches concentrate on the latter. Local projection directions derived from the partial least squares (PLS) algorithm offer an interesting trade-off between these two objectives. We apply these methods to several real data sets. In particular, we consider simulated astrophysical data from the future Galactic survey mission Gaia.Comment: 25 pages. In "Principal Manifolds for Data Visualization and Dimension Reduction", A. Gorban, B. Kegl, D. Wunsch, and A. Zinovyev (eds), Lecture Notes in Computational Science and Engineering, Springer, 2007, pp. 180--204, http://www.springer.com/dal/home/generic/search/results?SGWID=1-40109-22-173750210-

    Gauging the current status of natural history collections in Malaysia

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    This study was carried out to gauge the current status of natural history collection centres in Malaysia, primarily focused on animal collections. Part of the research is reported here and it constituted objective one which is to compare the status of natural history collection between the various centres in Malaysia and also with three selected Southeast Asian tropical region museums in trying to understand need of the Malaysian public for a natural history museum. It maps out the locations, describes the number and kinds of specimens kept at each collection centre. Financial and governance aspects are also described. In total 11 centres were visited all over Malaysia. These collection centres and museums were managed by federal or state government or universities. Duration of visit at each location ranged from one to seven days. During the visit interviews were carried out with collection manager to obtained Questionnaire was also left behind for managers of centre to fill in and sent back to researchers. In addition, three natural history collection centres and museums in South East Asia tropical region were also visited: Bogor Zoological Museum, Indonesia; Lee Kong Chian Natural History Museum, Singapore and Mahachakri Sirindhorn Natural History Museum, Prince of Songkhla University, Thailand. Following the same protocol as with Malaysian centres, the information obtained enable researcher to make comparison between Malaysia and those in the region. This paper found that most of the natural history museums and collection centres were focused in the centre of peninsular Malaysia. However, natural history collections in Malaysia are still limited by state and national borders. Coordination and integration of these centres, currently runned separately by the federal, state governments, research institutions and institution of higher learning, is seen as the way forward to provide for a strong basis of understanding biodiversity among the Malaysian public

    Effect of ripening on protein content and enzymatic activity of Crimson Seedless table grape

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    The evolution of Brix, protein content, polyphenoloxidase activity and peroxidase activity during the ripening of Crimson Seedless table grape was studied in three consecutive years (2006, 2007 and 2008). The total protein content was determined according to Bradford’s dye binding method, and polyphenoloxidase (PPO) and peroxidase (POD) were extracted using Triton X-114 and characterised using spectrophotometric methods. The year had a statistically significant effect on all the studied parameters and there was an interannual correlation in the evolution of protein, PPO, POD and Brix. All the studied parameters were statistically correlated, except POD activity with protein content. Weather conditions during the ripening period had a greater effect on protein content than PPO and POD activity.Ciencias de la Alimentació

    New Emigration and Portuguese Society: Transnationalism and Return

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    This chapter addresses the theme of transnationalism and return in recent Portuguese emigration, namely the flows that occurred after the turn of the century. It starts with a brief theoretical overview on those topics, which constitute two relatively neglected characteristics of Portuguese emigration. Next, based on a survey carried out in 2014–2015 to more than 6000 recent emigrants, it reveals some of the links that they maintain with their home country, as well as their plans for the future, which include settlement in the destination country, return and re-emigration. Lastly, it examines data on returning emigrants – especially those that returned between 2001 and 2011 – extracted from the 2011 Census. The evidence reveals a significant number of returns, including individuals at both working and retirement ages and at all skill levels, thus exposing the unexpected complexity of movements. The results are based on the research project “Back to the future: new emigration and links with Portuguese society” (REMIGR), which aimed to ascertain the extent and characteristics of the new emigration wave. The project included an overview of emigration and return to and from all regions of the world, as well as case studies in UK, France, Luxembourg, Angola, Mozambique and Brazil.info:eu-repo/semantics/publishedVersio

    Echoes of time. The mobility of Brazilian researchers and students in Portugal

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    A investigação que apresentamos, de caráter exploratório, recaiu sobre histórias biográficas de brasileiros que escolhem Portugal para prosseguir formação e ou investigação. Procura-se encontrar na sua experiência elos de ligação explicativos sobre as motivações e os processos que os trazem para Portugal, assim como as expetativas e os projetos que comportam para os seus futuros e que incluem, ou não, este país. Temos em conta, especialmente, a forma como essa narrativa transporta sentidos identitários decorrentes das formas de relacionamento intercultural e político entre Portugal e Brasil e formas de cooperação implícitas, assim como mapas representacionais acerca dos lugares de eleição para desenvolvimento de carreiras científicas e académicas. A nossa pesquisa incide sobre as informações recolhidas através de um inquérito por questionário e entrevistas realizadas junto de estudantes e bolseiros brasileiros em Portugal.We present an exploratory study that investigated biographical stories of Brazilians who choose to continue their education or develop research in Portugal. We sought to find in their experiences explanatory links connecting the motivations and processes that bring them to Portugal, as well as the expectations and projects that they hold for the future, which may include, or not, this country. We take into account, particularly, the way this narrative carries senses of identity arising from the forms of intercultural and political relationship between Portugal and Brazil, as well as implicit forms of cooperation and representations about the places chosen for the development of scientific and academic careers. Our research draws on information collected through a survey based on questionnaires and interviews with Brazilian students and scholarship holders in Portugal.(undefined

    Local linear regression with adaptive orthogonal fitting for the wind power application

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    Short-term forecasting of wind generation requires a model of the function for the conversion of me-teorological variables (mainly wind speed) to power production. Such a power curve is nonlinear and bounded, in addition to being nonstationary. Local linear regression is an appealing nonparametric ap-proach for power curve estimation, for which the model coefficients can be tracked with recursive Least Squares (LS) methods. This may lead to an inaccurate estimate of the true power curve, owing to the assumption that a noise component is present on the response variable axis only. Therefore, this assump-tion is relaxed here, by describing a local linear regression with orthogonal fit. Local linear coefficients are defined as those which minimize a weighted Total Least Squares (TLS) criterion. An adaptive es-timation method is introduced in order to accommodate nonstationarity. This has the additional benefit of lowering the computational costs of updating local coefficients every time new observations become available. The estimation method is based on tracking the left-most eigenvector of the augmented covari-ance matrix. A robustification of the estimation method is also proposed. Simulations on semi-artificial datasets (for which the true power curve is available) underline the properties of the proposed regression and related estimation methods. An important result is the significantly higher ability of local polynomia

    β-Cyclodextrins as affordable antivirals to treat coronavirus infection

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    The SARS-CoV-2 pandemic made evident that there are only a few drugs against coronavirus. Here we aimed to identify a cost-effective antiviral with broad spectrum activity and high safety profile. Starting from a list of 116 drug candidates, we used molecular modelling tools to rank the 44 most promising inhibitors. Next, we tested their efficacy as antivirals against α and β coronaviruses, such as the HCoV-229E and SARS-CoV-2 variants. Four drugs, OSW-1, U18666A, hydroxypropyl-β-cyclodextrin (HβCD) and phytol, showed in vitro antiviral activity against HCoV-229E and SARS-CoV-2. The mechanism of action of these compounds was studied by transmission electron microscopy and by fusion assays measuring SARS-CoV-2 pseudoviral entry into target cells. Entry was inhibited by HβCD and U18666A, yet only HβCD inhibited SARS-CoV-2 replication in the pulmonary Calu-3 cells. Compared to the other cyclodextrins, β-cyclodextrins were the most potent inhibitors, which interfered with viral fusion via cholesterol depletion. β-cyclodextrins also prevented infection in a human nasal epithelium model ex vivo and had a prophylactic effect in the nasal epithelium of hamsters in vivo. All accumulated data point to β-cyclodextrins as promising broad-spectrum antivirals against different SARS-CoV-2 variants and distant alphacoronaviruses. Given the wide use of β-cyclodextrins for drug encapsulation and their high safety profile in humans, our results support their clinical testing as prophylactic antivirals.This work has been funded by grant RTI2018-094445-B100 (MCIU/AEI/FEDER, UE) from the Ministry of Science and Innovation of Spain (C.R.), by Palex Medical S.A., Sika S.A.U. and 7 more companies, and by Ms. Raquel Casaus Alvarez, Mr. Miguel Pardo Gil, Mr. Jacques Noguès and a total of 2916 citizens through the Precipita crowdfunding platform of Fecyt (Fundación Española para la Ciencia y la Tecnología). NI-U is supported by the Spanish Ministry of Science and Innovation (grant PID2020-117145RB-I00), EU HORIZON-HLTH-2021-CORONA-01 (grant 101046118) and by institutional funding of Grifols, Pharma Mar, HIPRA, Amassence and Palobiofarma. This work used the computational resources of the Centro de Supercomputación de Galicia (CESGA) supported by the Partnership for Advanced Computing in Europe (PRACE) COVID-19 Fast Track Call for Proposals – Allocation Decision – Proposal COVID19-85.info:eu-repo/semantics/publishedVersio
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