131,686 research outputs found
Non prompt D-meson measurements with ALICE at the LHC
Get PDFThe production of hadrons with open heavy flavour (charm and beauty) in high-energy nucleus-nucleus collisions is a powerful tool to study the properties of the deconfined phase of strongly interacting matter known as the Quark-Gluon Plasma (QGP). The production of charm and beauty quarks occurs in hard partonic scattering processes in the early stage of the collisions. ALICE is the LHC experiment devoted to the study of heavy-ion physics. It is able to reconstruct charmed mesons in exclusive decays (e.g. D0→K−π+) and beauty hadrons in semi-inclusive decays (e.g. B→eX, B→J/ψ X) . At LHC energies a significant component of the inclusive D-meson yield originates from the decay of beauty-flavoured hadrons, whose knowledge is essential to determine the production of prompt D mesons coming from charm quarks. A precise determination of the non-prompt fraction combined with the determination of the inclusive D-meson yield would allow a measurement of beauty production. A data-driven method that exploits the different shapes of the distributions of the transverse-plane impact parameter to the primary vertex of prompt and feed-down D mesons in p-Pb collisions is used in ALICE. An alternative approach based on the D-meson decay length for Pb–Pb collisions is under study
Multidimensional indicators for evaluating impacts of climate change and air pollution on human health at local scale: a test case in Southern Italy.
No full textA dynamical systems approach to gross domestic product forecasting
No full textModels developed for gross domestic product (GDP) growth forecasting tend to be extremely complex, relying on a large number of variables and parameters. Such complexity is not always to the benefit of the accuracy of the forecast. Economic complexity constitutes a framework that builds on methods developed for the study of complex systems to construct approaches that are less demanding than standard macroeconomic ones in terms of data requirements, but whose accuracy remains to be systematically benchmarked. Here we develop a forecasting scheme that is shown to outperform the accuracy of the five-year forecast issued by the International Monetary Fund (IMF) by more than 25% on the available data. The model is based on effectively representing economic growth as a two-dimensional dynamical system, defined by GDP per capita and ‘fitness’, a variable computed using only publicly available product-level export data. We show that forecasting errors produced by the method are generally predictable and are also uncorrelated to IMF errors, suggesting that our method is extracting information that is complementary to standard approaches. We believe that our findings are of a very general nature and we plan to extend our validations on larger datasets in future work
EXTENSÃO UNIVERSITÁRIA COMO PRÁTICA FORMATIVA E PROJETO INSTITUCIONAL: UM OLHAR A PARTIR DA PEDAGOGIA UNIVERSITÁRIA
Get PDFEste trabalho sintetiza os resultados parciais da pesquisa, desenvolvida desde 2009 em três universidades, que objetiva compreender a relação entre as práticas e políticas de extensão e a qualificação do trabalho docente. Partindo da indissociabilidade entre ensino, pesquisa extensão como princípio fundador das universidades brasileiras, a pesquisa busca compreender como a prática extensionista pode promover a melhoria da qualidade do ensino. A metodologia qualitativa se desenvolve em dois momentos: inicialmente, levantamento de documentos institucionais que possibilitaram o entendimento de como tais instituições compreenderam a extensão e que práticas decorreram de tais concepções e, posteriormente, entrevistas semi-estruturadas com docentes que praticam a extensão. Utilizamos como referência as seguintes categorias teóricas: os conceitos de saberes e formação profissional docente, de Tardif; de extensão universitária, de Tavares; e o princípio da indissociabilidade entre ensino, pesquisa e extensão, de Mazzilli. As análises desenvolvidas apontam a extensão como elemento de qualificação do trabalho docente e do ensino de graduação socialmente referenciado e seu reconhecimento na formação de professores e alunos, muitas vezes distanciado da potencialização das experiências por parte das instituições universitárias
MeSH term explosion and author rank improve expert recommendations
Get PDFInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Assessment of epithelial cells’ immune and inflammatory response to Staphylococcus aureus when exposed to a macrolide
No full textNon-specific (innate) immune response plays a major role in defending the udder from bacterial
invasion. Moreover, recent investigations suggest that mammary gland epithelial cells (MGEC)
could have a large and important role as a source of soluble components of immune defences.
Despite many attempts to find other ways to control/prevent mastitis (i.e. vaccine) antimicrobial
therapy is still the most used and effective means of curing clinical and subclinical mastitis.
However, drug concentrations and therapy durations are far from the optimal in order to reduce
costs. Therefore, efficacy of antimicrobial therapy is dependent not only on the substance
activity but also on the positive interactions with the host innate immune response. Surprisingly,
information on these interactions is rather scarce in the mastitis field. A simple experimental
model was developed based on BME-UV cell line, Staphylococcus aureus as a challenge and a
macrolide as an antimicrobial to assess the interactions among epithelial cells, Staph. aureus
and the potential effects of antimicrobials on the immune system. The results of this study
confirmed that tylosin has good antimicrobial activity against both intracellular and extracellular
Staph. aureus in bovine MGEC without affecting cell functions. In this study, a significant downregulation
of IL-1 and IL-6 was observed, while TNF and IL-8 expression rate numerically
increased, but differences were not significant. To our knowledge, this is the first paper assessing
the concentration of two lysosomal enzymes, lysozyme and N-acetyl-b-D-glucosaminidase
(NAGase), in Staph. aureus-stimulated MGEC. The results of this study confirmed that tylosin
could have a significant effect on the release of these enzymes. Moreover, even if both enzymes
have a similar substrate as a target, the results suggest different secretion mechanisms and an
influence of antimicrobial treatment on these mechanisms. Successful mastitis cure is the result
of achieving the optimal efficiency of both innate immune defences and therapeutical activities,
by means of killing bacteria without eliciting an excessive inflammatory response. Therefore,
antimicrobials for mastitis therapy should be selected not only on bacterial sensitivity, but also
for their positive interactions with the innate immune response of the mammary gland. This
study showed that an in-vitro model based on Staph. aureus challenge on MGEC could be
helpful in assessing both the intracellular and extracellular activity of antimicrobials and their
influence on epithelial cell immune and inflammatory response
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