154 research outputs found

    Massive open star clusters using the VVV survey II. Discovery of six clusters with Wolf-Rayet stars

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    Context: The ESO Public Survey "VISTA Variables in the V\'ia L\'actea" (VVV) provides deep multi-epoch infrared observations for an unprecedented 562 sq. degrees of the Galactic bulge, and adjacent regions of the disk. In this survey nearly 150 new open clusters and cluster candidates have been discovered. Aims: This is the second in a series of papers about young, massive open clusters observed using the VVV survey. We present the first study of six recently discovered clusters. These clusters contain at least one newly discovered Wolf-Rayet (WR) star. Methods: Following the methodology presented in the first paper of the series, wide-field, deep JHKs VVV observations, combined with new infrared spectroscopy, are employed to constrain fundamental parameters for a subset of clusters. Results: We affirm that the six studied stellar groups are real young (2-7 Myr) and massive (between 0.8 and 2.2 10^3 Msol) clusters. They are highly obscured (Av ~ 5-24 mag) and compact (1-2 pc). In addition to WR stars, two of the six clusters also contain at least one red supergiant star. We claim the discovery of 8 new WR stars, and 3 stars showing WR-like emission lines which could be classified WR or OIf. Preliminary analysis provides initial masses of ~30-50 Msol for the WR stars. Finally,we discuss the spiral structure of the Galaxy using as tracers the six new clusters together with the previously studied VVV clusters.Comment: 17 pages, 8 figurs, accepted in A&

    Structurally Related Monoterpenes p-Cymene, Carvacrol and Thymol Isolated from Essential Oil from Leaves of Lippia sidoides Cham. (Verbenaceae) Protect Mice against Elastase-Induced Emphysema

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    Background: Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction and inflammation. Natural products, such as monoterpenes, displayed anti-inflammatory and anti-oxidant activities and can be used as a source of new compounds to COPD treatment. Our aim was to evaluate, in an elastase-induced pulmonary emphysema in mice, the effects of and underlying mechanisms of three related natural monoterpenes (p-cymene, carvacrol and thymol) isolated from essential oil from leaves Lippia sidoides Cham. (Verbenaceae). Methods: Mices received porcine pancreatic elastase (PPE) and were treated with p-cymene, carvacrol, thymol or vehicle 30 min later and again on 7th, 14th and 28th days. Lung inflammatory profile and histological sections were evaluated. Results: In the elastase-instilled animals, the tested monoterpenes reduced alveolar enlargement, macrophages and the levels of IL-1 beta, IL-6, IL-8 and IL-17 in bronchoalveolar lavage fluid (BALF), and collagen fibers, MMP-9 and p-65-NF-kappa B-positive cells in lung parenchyma (p < 0.05). All treatments attenuated levels of 8-iso-PGF2 alpha but only thymol was able to reduced exhaled nitric oxide (p < 0.05). Conclusion: Monoterpenes p-cymene, carvacrol and thymol reduced lung emphysema and inflammation in mice. No significant differences among the three monoterpenes treatments were found, suggesting that the presence of hydroxyl group in the molecular structure of thymol and carvacrol do not play a central role in the anti-inflammatory effects.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Laboratorio de Investigacao Medica, Hospital das Clinicas, Faculdade de Medicina, University of Sao Paulo (LIM)Univ Fed Sao Paulo, Dept Biol Sci, BR-09913030 Diadema, BrazilUniv Sao Paulo, Sch Med, Dept Med, BR-01246903 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, Dept Exact Sci & Earth, BR-09913030 Diadema, BrazilFed Univ ABC, Ctr Nat Sci & Humanities, BR-09606045 Santo Andre, SP, BrazilUniv Fed Sao Paulo, Dept Biosci, Campus Baixada Santista, BR-11015020 Santos, SP, BrazilDepartment of Biological Science, Universidade Federal de São Paulo, Diadema 09913-030, BrazilDepartment of Exact Science and Earth, Universidade Federal de São Paulo, Diadema 09913-030, BrazilDepartment of Bioscience, Federal University of São Paulo, Campus Baixada Santista, Santos 11015-020, SP, BrazilCNPq: 300546/2012-2CNPq: 304465/2012-7CNPq: 476877/2012-1CNPq: 306278/2015-4FAPESP: 2011/51739-0FAPESP: 2013/02881-4FAPESP: 2008/55359-5FAPESP: 2015/11936-2FAPESP: 2014/25689-4LIM: LIM20Web of Scienc

    Gene diversity in grevillea populations introduced in Brazil and its implication on management of genetic resources.

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    A variabilidade isoenzimática para seis populações de Grevillea robusta, oriundas de um teste de procedências/progenies, implantado no delineamento em blocos casualizados com 5 plantas por parcela, no Sul do Brasil, é descrita. A estrutura genética da população foi analisada utilizando-se marcadores bioquímicos, aos 5 anos de idade, especificamente para os locos MDH-3, PGM-2, DIA-2, PO-1, PO-2, SOD-1, e SKDH-1. As procedências do norte de ocorrência natural (Rathdowney e Woodenbong) apresentaram divergência genética superior, em relação à média das progênies, considerando o número de alelos por locus, (Ap), a riqueza alélica (Rs), a diversidade genética de Nei (H), e o coeficiente de endogamia (f). A endogamia foi detectada em diversos graus. A testemunha comercial apresentou o maior coeficiente de endogamia, (f = 0,4448), comparativamente à média das procedências (f = 0,2306), possivelmente devido à insuficiente amostragem populacional na região de origem (Austrália). Apesar de sua ocorrência natural restrita, observou-se correlação positiva entre divergência genética e distância geográfica entre as populações originais. A distância genética e análise de cluster, baseada no modelo bayesiano, mostrou três grupos de procedências distintos: 1) Rathdowney- QLD e Woodenbong-QLD; 2) Paddy?s Flat-NSW; e 3) Mann River-NSW, Boyd River-NSW e a testemunha comercial (material utilizado no Brasil). O agrupamento da testemunha com as procedências Mann River-NSW e Boyd River-NSW sugere um maior potencial das procedências do norte para o melhoramento genético visando à produção de madeira no Brasil, devido a sua elevada diversidade genética e baixo coeficiente de endogamia

    Absence of Myocardial Thyroid Hormone Inactivating Deiodinase Results in Restrictive Cardiomyopathy in Mice

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    Cardiac injury induces myocardial expression of the thyroid hormone inactivating type 3 deiodinase (D3), which in turn dampens local thyroid hormone signaling. Here, we show that the D3 gene (Dio3) is a tissue-specific imprinted gene in the heart, and thus, heterozygous D3 knockout (HtzD3KO) mice constitute a model of cardiac D3 inactivation in an otherwise systemically euthyroid animal. HtzD3KO newborns have normal hearts but later develop restrictive cardiomyopathy due to cardiac-specific increase in thyroid hormone signaling, including myocardial fibrosis, impaired myocardial contractility, and diastolic dysfunction. In wild-type littermates, treatment with isoproterenol-induced myocardial D3 activity and an increase in the left ventricular volumes, typical of cardiac remodeling and dilatation. Remarkably, isoproterenol-treated HtzD3KO mice experienced a further decrease in left ventricular volumes with worsening of the diastolic dysfunction and the restrictive cardiomyopathy, resulting in congestive heart failure and increased mortality. These findings reveal crucial roles for Dio3 in heart function and remodeling, which may have pathophysiologic implications for human restrictive cardiomyopathy

    The genomes of two key bumblebee species with primitive eusocial organization

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    Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

    p27 Deficiency Cooperates with Bcl-2 but Not Bax to Promote T-Cell Lymphoma

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    The effect of Bcl-2 on oncogenesis is complex and expression may either delay or accelerate oncogenesis. The pro-oncogenic activity is attributed to its well characterized anti-apoptotic function while the anti-oncogenic function has been attributed to its inhibition of cellular proliferation. Recent studies demonstrate that p27 may mediate the effects of Bcl-2 on cellular proliferation. We hypothesized that p27 may suppress tumor formation by Bcl-2 family members. To test this hypothesis, cell cycle inhibition and lymphoma development were examined in Lck-Bcl-2 and Lck-Bax38/1 transgenic mice deficient in p27. Strikingly, p27 deficiency synergistically cooperates with Bcl-2 to increase T cell hyperplasia and development of spontaneous T cell lymphomas. Within 1 year, >90% of these mice had developed thymic T cell lymphomas. This high penetrance contrasts with a one year incidence of <5% of thymic lymphoma in Lck-Bcl-2 or p27 −/− mice alone. In contrast, p27 deficiency had no effect on tumor formation in Lck-Bax38/1 transgenic mice, another model of T cell lymphoma. Histologically the lymphomas in p27 −/− Lck-Bcl-2 mice are lymphoblastic and frequently involve multiple organs suggesting an aggressive phenotype. Interestingly, in mature splenic T cells, Bcl-2 largely retains its anti-proliferative function even in the absence of p27. T cells from p27 −/− Lck-Bcl-2 mice show delayed kinetics of CDK2 Thr-160 phosphorylation. This delay is associated with a delay in the up regulation of both Cyclin D2 and D3. These data demonstrate a complex relationship between the Bcl-2 family, cellular proliferation, and oncogenesis and demonstrate that p27 up-regulation is not singularly important in the proliferative delay observed in T cells expressing Bcl-2 family members. Nonetheless, the results indicate that p27 is a critical tumor suppressor in the context of Bcl-2 expression
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