90 research outputs found

    Óleos essenciais de espĂ©cies do gĂȘnero Aniba

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    Most Aniba (Lauraceae) species occur in Amazonia. They are represented by trees which contain essential oil in all of their organs. Oils from different organs of any species show little variation in composition. In contradistinction, such surprisingly drastic variation may be noted among different species, that they can be classified into groups. The linalool - group comprises A. duckei Kosterm. and A. rosaeodora Ducke. The benzyl benzoate - group comprises A. burchellii Kosterm., A. firmula (Nees et Mart.) Mez., A. fragrans Ducke, A. gardneri (Meissn.) Mez, A. guianensis Aubl., A. parviflora (Meissn.) Mez and A. permollis (Nees) Mez. The allylbenzene - group comprises A. canelilla (H.B.K.) Mez. A. hostmanniana (Nees) Mez and A. pseudocoto (Rusby) Kosterm. Detailed analysis revealed the presence in some of these oils of such rare plant products as l-nitro-2-phenylethane, phenylathyl benzoate, O-methylisoeugenol and 2, 4, 5-trimethoxyallylbenzene.A maior parte das espĂ©cies de Aniba (Lauraceae) se encontra na AmazĂŽnia. SĂŁo representadas por ĂĄrvores que contĂȘm Ăłleo essencial em todos os seus ĂłrgĂŁos. Os Ăłleos dos diferentes ĂłrgĂŁos de qualquer espĂ©cie mostram somente uma pequena variação em sua composição. Em contrapartida, pode ser notada uma variação tĂŁo surpreendentemente drĂĄstica entre espĂ©cies diferentes que podem ser classificadas em grupos. O grupo linalol compreende A. duckei Kosterm. e A. rosaeodora Ducke. O grupo benzoato de benzilo compreende A. burchellii Kosterm., A. firmula (Nees & Mart.) Mez., A. fragrans Ducke, A. gardneri (Meissn.) Mez, A. guianensis Aubl., A. parviflora (Meissn.) Mez. e A. permollis (Nees) Mez. O grupo alilbenzeno compreende A. canelilla (H.B.K.) Mez., A. hostmanniana (Nees) Mez e A. pseudocoto (Rusby) Kosterm. A anĂĄlise detalhada revelou a presença, em alguns destes Ăłleos ,de produtos raros de plantas como l-nitro-2feniletano, benzoato de feniletilo O-metilisoeugenol e 2, 4, 5-trimetoxialilbenzeno

    BAFF Promotes Th17 Cells and Aggravates Experimental Autoimmune Encephalomyelitis

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    BAFF, in addition to promoting B cell survival and differentiation, may affect T cells. The objective of this study was to determine the effect of BAFF on Th17 cell generation and its ramifications for the Th17 cell-driven disease, EAE.Th17 cells were increased in BAFF-Tg B6 (B6.BTg) mice and decreased in B6.Baff(-/-) mice. Th17 cells in B6.Baff(-/-) mice bearing a BAFF Tg (B6.Baff(-/-).BTg mice) were identical to those in B6.BTg mice, indicating that membrane BAFF is dispensable for Th17 cell generation as long as soluble BAFF is plentiful. In T + non-T cell criss-cross co-cultures, Th17 cell generation was greatest in cultures containing B6.BTg T cells and lowest in cultures containing B6.Baff(-/-) T cells, regardless of the source of non-T cells. In cultures containing only T cells, Th17 cell generation followed an identical pattern. CD4(+) cell expression of CD126 (IL-6R α chain) was increased in B6.BTg mice and decreased in B6.Baff(-/-) mice, and activation of STAT3 following stimulation with IL-6 + TGF-ÎČ was also greatest in B6.BTg cells and lowest in B6.Baff(-/-) cells. EAE was clinically and pathologically most severe in B6.BTg mice and least severe in B6.Baff(-/-) mice and correlated with MOG(35-55) peptide-induced Th17 cell responses.Collectively, these findings document a contribution of BAFF to pathogenic Th17 cell responses and suggest that BAFF antagonism may be efficacious in Th17 cell-driven diseases

    Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research

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    Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes

    Mapping cortical brain asymmetry in 17,141 healthy individuals worldwide via the ENIGMA Consortium.

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    Hemispheric asymmetry is a cardinal feature of human brain organization. Altered brain asymmetry has also been linked to some cognitive and neuropsychiatric disorders. Here, the ENIGMA (Enhancing NeuroImaging Genetics through Meta-Analysis) Consortium presents the largest-ever analysis of cerebral cortical asymmetry and its variability across individuals. Cortical thickness and surface area were assessed in MRI scans of 17,141 healthy individuals from 99 datasets worldwide. Results revealed widespread asymmetries at both hemispheric and regional levels, with a generally thicker cortex but smaller surface area in the left hemisphere relative to the right. Regionally, asymmetries of cortical thickness and/or surface area were found in the inferior frontal gyrus, transverse temporal gyrus, parahippocampal gyrus, and entorhinal cortex. These regions are involved in lateralized functions, including language and visuospatial processing. In addition to population-level asymmetries, variability in brain asymmetry was related to sex, age, and intracranial volume. Interestingly, we did not find significant associations between asymmetries and handedness. Finally, with two independent pedigree datasets (n = 1,443 and 1,113, respectively), we found several asymmetries showing significant, replicable heritability. The structural asymmetries identified and their variabilities and heritability provide a reference resource for future studies on the genetic basis of brain asymmetry and altered laterality in cognitive, neurological, and psychiatric disorders

    History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience

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