1,846 research outputs found
J-PLUS: A wide-field multi-band study of the M15 globular cluster. Evidence of multiple stellar populations in the RGB
The Javalambre Photometric Local Universe Survey (J-PLUS) provides wide
field-of-view images in 12 narrow, intermediate and broad-band filters
optimized for stellar photometry. Here we have applied J-PLUS data for the
first time for the study of Galactic GCs using science verification data
obtained for the very metal-poor GC M\,15. Our J-PLUS data provide
low-resolution spectral energy distributions covering the near-UV to the
near-IR, allowing us to search for MPs based on pseudo-spectral fitting
diagnostics. J-PLUS CMDs are found to be particularly useful to search for
splits in the sequences formed by the upper red giant branch (RGB) and
asymptotic giant branch (AGB) stars. We interpret these split sequences as
evidence for the presence of MPs. This demonstrates that the J-PLUS survey will
have sufficient spatial coverage and spectral resolution to perform a large
statistical study of GCs through multi-band photometry in the coming years.Comment: 11 pages, 11 figures. Accepted for publication @ A&
In vitro Anti-HMPV activity of new synthetic phenytoin derivatives
New derivatives of synthetic 5,5-diphenylhydantoin (phenytoin) were prepared by N-alkylation with 1,3-dibromopropane. Subsequent treatment with sodium azide led to the respective azide. Reaction of the azide with phenylacetylene and 2-hydroxy-3-butyne and oxidation of the resulting alcohol with MnO2 resulted in three triazolic compounds that were evaluated in vitro for their antiviral activity against human metapneumovirus (HMPV). 5,5-Diphenyl-3-[3-(4-phenyl-1H-1,2,3-triazol-1-yl)propyl]imidazolidine-2,4-dione was the most active of the three compounds tested, with selectivity index of 129.87, even higher than ribavirin, the control substance. The three compounds showed activity in the early stages of viral replication presenting virucidal activity and binding to cellular receptors, preventing the adsorption of viral particles. These compounds showed higher activity in both experiments, inhibiting 98.3% of infection as virucidal and 98.9% when interacting with cellular receptors. Furthermore, they showed 73.8% of activity during the penetration of HMPV particles into cells. The derivative 3-{3-[4-(1-hydroxyethyl)-1H-1,2,3-triazol-1-yl]propyl}-5,5-diphenylimidazolidine-2,4-dione presented a mild anti-HMPV activity, with selectivity index of 2.74. 3-[3-(4-acetyl-1H-1,2,3-triazol-1-yl)propyl]-5,5-diphenylimidazolidine-2,4-dione inhibited less than 50% of HMPV replication
Comparative transcriptomic analysis reveals similarities and dissimilarities in saccharomyces cerevisiae wine strains response to nitrogen availability
Nitrogen levels in grape-juices are of major importance in winemaking ensuring adequate yeast growth and fermentation performance. Here we used a comparative transcriptome analysis to uncover wine yeasts responses to nitrogen availability during fermentation. Gene expression was assessed in three genetically and phenotypically divergent commercial wine strains (CEG, VL1 and QA23), under low (67 mg/L) and high nitrogen (670 mg/L) regimes, at three time points during fermentation (12h, 24h and 96h). Two-way ANOVA analysis of each fermentation condition led to the identification of genes whose expression was dependent on strain, fermentation stage and on the interaction of both factors. The high fermenter yeast strain QA23 was more clearly distinct from the other two strains, by differential expression of genes involved in flocculation, mitochondrial functions, energy generation and protein folding and stabilization. For all strains, higher transcriptional variability due to fermentation stage was seen in the high nitrogen fermentations. A positive correlation between maximum fermentation rate and the expression of genes involved in stress response was observed. The finding of common genes correlated with both fermentation activity and nitrogen up-take underlies the role of nitrogen on yeast fermentative fitness. The comparative analysis of genes differentially expressed between both fermentation conditions at 12h, where the main difference was the level of nitrogen available, showed the highest variability amongst strains revealing strain-specific responses. Nevertheless, we were able to identify a small set of genes whose expression profiles can quantitatively assess the common response of the yeast strains to varying nitrogen conditions. The use of three contrasting yeast strains in gene expression analysis prompts the identification of more reliable, accurate and reproducible biomarkers that will facilitate the diagnosis of deficiency of this nutrient in the grape-musts and the development of strategies to optimize yeast performance in industrial fermentations
Plasminogen Binding Proteins and Plasmin Generation on the Surface of Leptospira
Leptospirosis is considered a neglected infectious disease of human and veterinary concern. Although extensive investigations on host-pathogen interactions have been pursued by several research groups, mechanisms of infection, invasion and persistence of pathogenic Leptospira spp. remain to be elucidated. We have reported the ability of leptospires to bind human plasminogen (PLG) and to generate enzimatically active plasmin (PLA) on the bacteria surface. PLA-coated Leptospira can degrade immobilized ECM molecules, an activity with implications in host tissue penetration. Moreover, we have identified and characterized several proteins that may act as PLG-binding receptors, each of them competent to generate active plasmin. The PLA activity associated to the outer surface of Leptospira could hamper the host immune attack by conferring the bacteria some benefit during infection. The PLA-coated leptospires obstruct complement C3b and IgG depositions on the bacterial surface, most probably through degradation. The decrease of leptospiral opsonization might be an important aspect of the immune evasion strategy. We believe that the presence of PLA on the leptospiral surface may (i) facilitate host tissue penetration, (ii) help the bacteria to evade the immune system and, as a consequence, (iii) permit Leptospira to reach secondary sites of infection
Assets em Áreas Protegidas: Estudo de Caso em Áreas Úmidas
As áreas protegidas (APs) são as principais ferramentas capazes de assegurar a preservaçãodos sistemas naturais e sua respectiva biodiversidade, principalmente no caso de áreas com prioridade para conservação, como ocorre com as áreas úmidas. A implementação de APs tem potencial para gerar benefícios fundamentais para proteger paisagens icônicas, espécies ameaçadas e serviços ecossistêmicos; entretanto, essas áreas têm custos sociais e econômicos que, muitas vezes, se tornam difíceis de justificar em períodos de crescente insegurança alimentar e crise financeira. Recentemente, sugeriu-se um modelo conceitual para apoiar a gestão das APs (PA Asset Framework) que (re)define as APs como um sistema de assets biofísicos, humanos, de infraestrutura, institucionais e culturais. De acordo com esse marco, as APs podem ser geridas e planejadas para gerar diferentes formas de valores, desse modo contribuindo para aumentar sua resiliência política/social e identificar investimentos financeiros que possam auxiliar o reconhecimento e a captura de valores por distintos públicos. Neste artigo, aplicamos o PA asset framework para levantar a presença de assets em parques nacionais localizados em áreas úmidas, a partir da revisão sistemática dos planos de manejo. Nestes, identificamos os assets presentes e mais recorrentes em tais áreas. Nossos resultados mostram que o número de assets representados e reconhecidos nos planos de manejo é limitado, concentrando-se, principalmente, em algumas classes biofísicas relacionadas à conservação da biodiversidade (ex: espécies de importância para a conservação e espécies de importância econômica), de infraestrutura necessária paramanutenção das atividades de gestão (ex: funcionário permanente, infraestrutura para gestão, eletricidade e veículos) e institucionais (estratégias de planejamento e zoneamento). Por outro lado, dada a importância sociocultural das áreas úmidas em nível nacional e global, o baixo reconhecimento de assets humanos e culturais nessas áreas sugere que a inclusão desses valores nos planos de manejo pode ser benéfica para potencializar os valores associados a essas tipologias de asset. Argumentamos que o levantamento dos assets em APs, além de revelar os bens/recursos/atributos/dimensões-chave que podem estar sendo negligenciados nos planos de manejo, oferece uma abordagem inovadora para que os gestores possam elaborar estratégias de investimento a partir do reconhecimento de valores tangíveis e intangíveis das APs e dos seus assets, para além dos biofísicos
EQUIPES DE ATENÇÃO PRIMÁRIA: DIFICULDADES NO CUIDADO DE PESSOAS COM DOENÇAS CRÔNICAS NÃO TRANSMISSÍVEIS
Ag85-focused T-cell immune response controls Mycobacterium avium chronic infection
CD4+ T cells are essential players for the control of mycobacterial infections. Several mycobacterial antigens have been identified for eliciting a relevant CD4+ T cell mediated-immune response, and numerous studies explored this issue in the context of Mycobacterium tuberculosis infection. Antigen 85 (Ag85), a highly conserved protein across Mycobacterium species, is secreted at the early phase of M. tuberculosis infection leading to the proliferation of Ag85-specific CD4+ T cells. However, in the context of Mycobacterium avium infection, little is known about the expression of this antigen and the elicited immune response. In the current work, we investigated if a T cell receptor (TCR) repertoire mostly, but not exclusively, directed at Ag85 is sufficient to mount a protective immune response against M. avium. We show that P25 mice, whose majority of T cells express a transgenic TCR specific for Ag85, control M. avium infection at the same level as wild type (WT) mice up to 20 weeks post-infection (wpi). During M. avium infection, Ag85 antigen is easily detected in the liver of 20 wpi mice by immunohistochemistry. In spite of the propensity of P25 CD4+ T cells to produce higher amounts of interferon-gamma (IFNγ) upon ex vivo stimulation, no differences in serum IFNγ levels are detected in P25 compared to WT mice, nor enhanced immunopathology is detected in P25 mice. These results indicate that a T cell response dominated by Ag85-specific T cells is appropriate to control M. avium infection with no signs of immunopathology.This work was developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). Fellowships from the Portuguese Foundation for Science and Technoloy (FCT) were attributed to BCR (SFRH/BD/80352/2011; QREN-POPH through the Fundo Social Europeu (FSE) and national funds from MEC] and to CN (SFRH/BPD/112001/2015; POPH through FSE and national funds from MCTES). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
OBSERVATORIO TERRITORIAL Y AMBIENTAL ALENTEJO, EXTREMADURA, CENTRO (OTALEX C): DE GIS A IDE.
In the scope of the Spain-Portugal INTERREG projects and FEDER funded POCTEP program, OTALEX C (Territorial and Environmental Monitoring Alentejo Extremadura Center) project aims at studying of various territorial, socioeconomic and environmental indicators. It is the fundamental objective of this project, to develop a geo-portal accessible via internet, for anyone, so that the information will be useful in making decisions related to land use and therefore sustainable development of the environment.
Under this general framework over the past fifteen years, we have developed different projects that have set the standardization of data between Portugal and Spain, also was designed GIS systems, and developed regional models and indicator systems, culminating in the current Spatial Data Infrastructure SDI-OTALEX C
Chagasic Thymic Atrophy Does Not Affect Negative Selection but Results in the Export of Activated CD4+CD8+ T Cells in Severe Forms of Human Disease
Extrathymic CD4+CD8+ double-positive (DP) T cells are increased in some pathophysiological conditions, including infectious diseases. In the murine model of Chagas disease, it has been shown that the protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironment and the lymphoid compartment. In the acute phase, this results in a severe atrophy of the organ and early release of DP cells into the periphery. To date, the effect of the changes promoted by the parasite infection on thymic central tolerance has remained elusive. Herein we show that the intrathymic key elements that are necessary to promote the negative selection of thymocytes undergoing maturation during the thymopoiesis remains functional during the acute chagasic thymic atrophy. Intrathymic expression of the autoimmune regulator factor (Aire) and tissue-restricted antigen (TRA) genes is normal. In addition, the expression of the proapoptotic Bim protein in thymocytes was not changed, revealing that the parasite infection-induced thymus atrophy has no effect on these marker genes necessary to promote clonal deletion of T cells. In a chicken egg ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic system, the administration of OVA peptide into infected mice with thymic atrophy promoted OVA-specific thymocyte apoptosis, further indicating normal negative selection process during the infection. Yet, although the intrathymic checkpoints necessary for thymic negative selection are present in the acute phase of Chagas disease, we found that the DP cells released into the periphery acquire an activated phenotype similar to what is described for activated effector or memory single-positive T cells. Most interestingly, we also demonstrate that increased percentages of peripheral blood subset of DP cells exhibiting an activated HLA-DR+ phenotype are associated with severe cardiac forms of human chronic Chagas disease. These cells may contribute to the immunopathological events seen in the Chagas disease
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