1,134 research outputs found
Aplicação de Multiclassificadores Heterogêneos no Reconhecimento de Classes Estruturais de Proteínas
O reconhecimento de dobras de proteína é um dos principais problemas em aberto da biologia molecular e uma importante abordagem para a descoberta de estruturas de proteínas desconsiderando a similaridade de suas seqüências. Neste contexto, as ferramentas computacionais, principalmente as técnicas da Aprendizagem de Máquina (AM), tornaram-se alternativas essenciais para tratar esse problema, considerando o grande volume de dados empregado. Este trabalho apresenta os resultados obtidos com a aplicação de diferentes sistemas multiclassificadores heterogêneos (Stacking, StackingC e Vote), empregando tipos distintos de classificadores base (Árvores de Decisão, K-Vizinhos Mais próximos, Naive Bayes, Máquinas de Vetores Suporte e Redes Neurais), à tarefa de predição de classes estruturais de proteína
Closed circuits : kinship, neighborhood and incarceration in urban Portugal
The notion that prisons are a ‘world apart’, with their
walls severing prisoners from their external relationships, and
incarceration an interruption, ‘time away’ spent in a separate social
universe, has provided an adequate framework for understanding the
social realities of imprisonment in the past. But it has also created an
analytical dead angle that prevents us from identifying the ramifying
social effects of concentrated incarceration upon both the prison and
heavily penalized lower-class neighborhoods. This article addresses these
effects with data from an ethnographic revisit of a major women’s prison
in Portugal, where the recomposition of the inmate population that has
accompanied the rapid inflation of the country’s carceral population is
especially pronounced and entails the activation of wide-ranging
carceralized networks bringing kinship and neighborhood into the prison
as well as the prison into the domestic world. The analysis focuses on the
ways whereby these constellations have transformed the experience of
confinement and the texture of correctional life, calling for a
reconsideration of the theoretical status of the prison as a ‘total
institution’ and for exploring anew the boundary that separates it (or not)
from outside worlds.Wenner-Gren Foundation for Anthropological Research
N,N-Dialkyl-2-phenylindol-3-ylglyoxylamides. A new class of Potent and Selective Ligands at the Peripheral Benzodiazepine Receptor.
We report the synthesis and the affinity data at both the peripheral (PBR) and the central benzodiazepine receptors of a series of N,N-dialkyl-2-phenylindol-3-ylglyoxylamide derivatives III, designed as conformationally constrained analogues of 2-phenylindole-3-acetamides II such as FGIN-1-27. Most of the new compounds showed a high specificity and affinity for PBR, with Ki in the nanomolar to subnanomolar range. The most potent ligands (4−7, 9, 13−27) stimulated steroid biosynthesis in rat C6 glioma cells with a potency similar to or higher than that of classical ligands. The SARs of this new class of compounds are discussed
Large-scale collective motion of RFGC galaxies
We processed the data about radial velocities and HI linewidths for 1678 flat
edge-on spirals from the Revised Flat Galaxy Catalogue. We obtained the
parameters of the multipole components of large-scale velocity field of
collective non-Hubble galaxy motion as well as the parameters of the
generalized Tully-Fisher relationship in the "HI line width - linear diameter"
version. All the calculations were performed independently in the framework of
three models, where the multipole decomposition of the galaxy velocity field
was limited to a dipole, quadrupole and octopole terms respectively. We showed
that both the quadrupole and the octopole components are statistically
significant.
On the basis of the compiled list of peculiar velocities of 1623 galaxies we
obtained the estimations of cosmological parameters Omega_m and sigma_8. This
estimation is obtained in both graphical form and as a constraint of the value
S_8=sigma_8(Omega_m/0.3)^0.35 = 0.91 +/- 0.05.Comment: Accepted for publication in Astrophysics and Space Scienc
Integrated Health Service Delivery Networks And Tuberculosis Avoidable Hospitalizations: Is There A Relation Between Them In Brazil?
The early identification of the Breathing Symptoms within the scope of Primary Health Care is recommended, and is also one of the strategies of national sanitary authorities for reaching the elimination of tuberculosis. The purpose of this study is to consider which attributes and which territories have shown the most significant progress in Primary Health Care, in terms of coordination of Health Care Networks, and also check if those areas of Primary Health Care that are most critical regarding coordination, there were more or less cases of avoidable hospitalizations for tuberculosis. Methods: This is an ecological study that uses primary and secondary data. For analysis, coropletic maps were developed through the ArcGIS software, version 10.2. There was also the calculation of gross annual and Bayesian rates for hospitalizations for tuberculosis, for each Primary Health Care territory. Results: There were satisfactory results for attributes such as Population (n = 37; 80.4 %), Primary Health Care (n = 43; 93.5 %), Support System (n = 45; 97.8 %); the exceptions were Logistics System (n = 32; 76.0 %) and Governance System, with fewer units in good condition (n = 31; 67.3 %). There is no evidence of any connection between networks' coordination by Primary Health Care and tuberculosis avoidable admissions. Conclusion: The results show that progress has been made regarding the coordination of the Health Care Networks, and a positive trend has been shown, even though the levels are not excellent. It was found no relationship between the critical areas of Primary Health Care and tuberculosis avoidable hospitalizations, possibly because other variables necessary to comprehend the phenomena. © 2016 Popolin et al.16
The fraction of cancer attributable to ways of life, infections, occupation, and environmental agents in Brazil in 2020
Many human cancers develop as a result of exposure to risk factors related to the environment and ways of life. The aim of this study was to estimate attributable fractions of 25 types of cancers resulting from exposure to modifiable risk factors in Brazil. The prevalence of exposure to selected risk factors among adults was obtained from population-based surveys conducted from 2000 to 2008. Risk estimates were based on data drawn from metaanalyses or large, high quality studies. Population-attributable fractions (PAF) for a combination of risk factors, as well as the number of preventable deaths and cancer cases, were calculated for 2020. The known preventable risk factors studied will account for 34% of cancer cases among men and 35% among women in 2020, and for 46% and 39% deaths, respectively. The highest attributable fractions were estimated for tobacco smoking, infections, low consumption of fruits and vegetables, excess weight, reproductive factors, and physical inactivity. This is the first study to systematically estimate the fraction of cancer attributable to potentially modifiable risk factors in Brazil. Strategies for primary prevention of tobacco smoking and control of infection and the promotion of a healthy diet and physical activity should be the main priorities in policies for cancer prevention in the country. \ua9 2016 Azevedo e Silva et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Endosymbiosis in trypanosomatids: the genomic cooperation between bacterium and host in the synthesis of essential amino acids is heavily influenced by multiple horizontal gene transfers
Background
Trypanosomatids of the genera Angomonas and Strigomonas live in a mutualistic association characterized by extensive metabolic cooperation with obligate endosymbiotic Betaproteobacteria. However, the role played by the symbiont has been more guessed by indirect means than evidenced. Symbiont-harboring trypanosomatids, in contrast to their counterparts lacking symbionts, exhibit lower nutritional requirements and are autotrophic for essential amino acids. To evidence the symbiont’s contributions to this autotrophy, entire genomes of symbionts and trypanosomatids with and without symbionts were sequenced here. Results
Analyses of the essential amino acid pathways revealed that most biosynthetic routes are in the symbiont genome. By contrast, the host trypanosomatid genome contains fewer genes, about half of which originated from different bacterial groups, perhaps only one of which (ornithine cyclodeaminase, EC:4.3.1.12) derived from the symbiont. Nutritional, enzymatic, and genomic data were jointly analyzed to construct an integrated view of essential amino acid metabolism in symbiont-harboring trypanosomatids. This comprehensive analysis showed perfect concordance among all these data, and revealed that the symbiont contains genes for enzymes that complete essential biosynthetic routes for the host amino acid production, thus explaining the low requirement for these elements in symbiont-harboring trypanosomatids. Phylogenetic analyses show that the cooperation between symbionts and their hosts is complemented by multiple horizontal gene transfers, from bacterial lineages to trypanosomatids, that occurred several times in the course of their evolution. Transfers occur preferentially in parts of the pathways that are missing from other eukaryotes. Conclusion
We have herein uncovered the genetic and evolutionary bases of essential amino acid biosynthesis in several trypanosomatids with and without endosymbionts, explaining and complementing decades of experimental results. We uncovered the remarkable plasticity in essential amino acid biosynthesis pathway evolution in these protozoans, demonstrating heavy influence of horizontal gene transfer events, from Bacteria to trypanosomatid nuclei, in the evolution of these pathways
Correlation between centrality metrics and their application to the opinion model
In recent decades, a number of centrality metrics describing network
properties of nodes have been proposed to rank the importance of nodes. In
order to understand the correlations between centrality metrics and to
approximate a high-complexity centrality metric by a strongly correlated
low-complexity metric, we first study the correlation between centrality
metrics in terms of their Pearson correlation coefficient and their similarity
in ranking of nodes. In addition to considering the widely used centrality
metrics, we introduce a new centrality measure, the degree mass. The m order
degree mass of a node is the sum of the weighted degree of the node and its
neighbors no further than m hops away. We find that the B_{n}, the closeness,
and the components of x_{1} are strongly correlated with the degree, the
1st-order degree mass and the 2nd-order degree mass, respectively, in both
network models and real-world networks. We then theoretically prove that the
Pearson correlation coefficient between x_{1} and the 2nd-order degree mass is
larger than that between x_{1} and a lower order degree mass. Finally, we
investigate the effect of the inflexible antagonists selected based on
different centrality metrics in helping one opinion to compete with another in
the inflexible antagonists opinion model. Interestingly, we find that selecting
the inflexible antagonists based on the leverage, the B_{n}, or the degree is
more effective in opinion-competition than using other centrality metrics in
all types of networks. This observation is supported by our previous
observations, i.e., that there is a strong linear correlation between the
degree and the B_{n}, as well as a high centrality similarity between the
leverage and the degree.Comment: 20 page
Estrutura de cardumes da sardinha-verdadeira, Sardinella brasiliensis (Steindachner, 1879), no estado do Rio de Janeiro (Brasil)
Culture-independent assessment of the diazotrophic Bradyrhizobium communities in the Pampa and Atlantic Forest Biomes localities in southern Brazil
The isolation of rhizobial strains from the root and stem nodules remains a commonly used method
despite its limitations as it enables the identification of mainly dominant symbiotic groups within rhizobial communities. To overcome these limitations, we used genus-specific nifD primers in a cultureindependent assessment of Bradyrhizobium communities inhabiting soils in southern Brazil. The majority
of nifD sequences were generated from DNA isolated from tropical-lowland pasture soils, although some
soil samples originated from the Campos de Cima da Serra volcanic plateau. In the nifD tree, all the
bradyrhizobial sequences comprised 38 clades, including 18 new clades. The sequences generated in this
study were resolved into 22 clades and 21 singletons. The nifD bradyrhizobial assemblage contained
Azorhizobium and a-proteobacterial methylotrophic genera, suggesting that these genera may have
acquired their nif loci from Bradyrhizobium donors. The most common in the lowland pasture soils subclade III.3D branch comprises the isolates of mainly an American origin. On the other hand, subclade III.4,
which was earlier detected in Brazil among Bradyrhizobium isolates nodulating native lupins, appears
more common in the Campos de Cima da Serra soils. The second-largest group, Clade XXXVIII, has not
yet been reported in culture-dependent studies, while another common group called Clade I represents
a symbiovar predominating in Australia. The identification of the diverse nifD Clade I haplotypes in the
tropical-lowland pastures infested by Australian Acacia spp implies that the introduction of these
legumes to southern Brazil has resulted in the dissemination of their bradyrhizobial symbionts.This work was supported by a grant UMO-2014/15/B/
NZ8/00259 (TS-JB) from The National Science Centre (NCN) and a
grant from CAPES/FAPERGS Public Notice 12/2013.http://www.elsevier.com/locate/syapmdm2022BiochemistryGeneticsMicrobiology and Plant Patholog
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