936 resultados para Aspect hypothesis
Resumo:
Lead poisoning has been reportedly linked to a high risk of learning disabilities, aggression and criminal offenses. To study the association between lead exposure and antisocial/delinquent behavior, a cross-sectional study was conducted with 173 Brazilian youths aged 14\201318 and their parents (n = 93), living in impoverished neighborhoods of Bauru-SP, with high criminality indices. Self-Reported Delinquency (SRD) and Child Behavior Checklist (CBCL) questionnaires were used to evaluate delinquent/antisocial behavior. Body lead burdens were evaluated in surface dental enamel acid microbiopsies. The dental enamel lead levels (DELL) were quantified by graphite furnace atomic absorption spectrometry (GFAAS) and phosphorus content was measured using inductively coupled plasma optical emission spectrometry (ICP-OES). Logistic regression was used to identify associations between DELL and each scale defined by CBCL and SRD scores. Odd ratios adjusted for familial and social covariates, considering a group of youths exposed to high lead levels (\2265 75 percentile), indicated that high DELL is associated with increased risk of exceeding the clinical score for somatic complaints, social problems, rule-breaking behavior and externalizing problems (CI 95 per cent). High DELL was not found to be associated with elevated SRD scores. In conclusion, our data support the hypothesis that high-level lead exposure can trigger antisocial behavior, which calls for public policies to prevent lead poisoning
Resumo:
INTRODUÇÃO: É reconhecida a efetividade de um treinamento para melhorar a qualidade no relato do consumo alimentar em adultos, porém poucos estudos avaliam esta efetividade em crianças. OBJETIVO: Investigar o efeito da realização de um treinamento para o desenvolvimento de habilidades para um correto preenchimento de um Diário Alimentar, por escolares de 7 a 10 anos. METODOLOGIA: O estudo foi conduzido em uma escola pública da cidade de São Paulo e envolveu a realização de 3 sessões de treinamento de 30 minutos cada, direcionadas a 40 escolares de ambos os sexos. Para verificação do efeito do treinamento, 3 examinadores avaliaram o preenchimento dos dados antes e após o mesmo. Foram atribuídos escores de 0 a 5 para aspectos relativos à identificação, detalhamento e quantificação do alimento consumido, e calculado o escore médio a partir dos escores de cada examinador para cada aspecto. Utilizou-se o teste de Wilcoxon para comparação de amostras dependentes. RESULTADOS: Foi constatada evidência estatística de diferença entre os escores antes e após o treinamento para os três aspectos: identificação (p < 0,001), detalhamento (p = 0,003) e quantificação do alimento (p < 0,001), sendo grande parte dos valores após o treinamento maiores que os iniciais. CONCLUSÃO: É possível aumentar a habilidade de escolares de 7 a 10 anos no preenchimento de um Diário Alimentar a partir da realização de um treinamento nos moldes apresentados neste artigo
Resumo:
Existem, atualmente, mais de 300 hipóteses relativas à caracterização, função e mecanismos do envelhecimento, possivelmente devido ao aumento de idosos no mundo. Embora se avente uma função social à velhice humana, as transformações da sociedade impuseram uma cultura de descarte, incluindo pessoas como os idosos. Tal exclusão, que se associa à tristeza, depressão e morte desse grupo, é contraditória ao aumento do tempo de vida dos idosos constatado atualmente. O presente trabalho tentou determinar os aspectos ambientais envolvidos na longevidade usando uma técnica de metodologia qualitativa denominada grounded theory (ou teoria fundamentada nos dados) em dados fornecidos por ex-ferroviários longevos. Constatou-se que as representações dos ex-ferroviários confluem para a categoria central: desolação pelo aniquilamento da vida e do ambiente, no presente, devido à continuada negligência do Estado e da Sociedade na promoção e preservação das coisas boas para a vida que havia no passado. Observou-se ainda que, paralelamente à hipervalorização genérica das coisas do passado, há constatação recente de que suas existências fizeram parte da epopeia que promoveu o desenvolvimento econômico e social do interior paulista e possibilitou uma ressignificação existencial do passado, sugerindo ser um potente mecanismo de defesa que culmina em longevidade. Tal achado se insere na hipótese de que a função da longevidade seria a de preservar um contingente social com conhecimentos de um modo de vida que deu certo por ser socialmente vantajoso
Resumo:
Os distúrbios psiquiátricos constituem um grave problema de saúde pública. Por muitos anos, a única terapêutica disponível ao portador de transtornos mentais era a internação em hospitais psiquiátricos. Hoje a Organização Mundial de Saúde recomenda os serviços de base comunitária como modelo de tratamento em saúde mental. Assim, o objetivo é descrever as características de uma rede de atenção à saúde mental de base comunitária no município de Santo André, SP. Foi realizado um estudo retrospectivo do tipo descritivo, em dados secundários do período de 1987 a 2006. O estudo incidiu sobre o histórico, a infra-estrutura, os recursos humanos, a produção, as práticas e processos de trabalho dos serviços de saúde mental de Santo André. Foram analisados documentos do Programa Municipal de Saúde Mental, da Secretaria Municipal de Saúde, da Prefeitura de Santo André, da Associação José Martins de Araújo Júnior-Organização Social De Volta Para Casa. A Secretaria Municipal de Saúde proveu meios para uma transformação dos serviços de saúde mental no período estudado, partindo de um atendimento exclusivamente manicomial para uma rede de serviços de saúde mental com modelo centrado na comunidade, focando a doença no aspecto psicossocial e com abordagem por equipe multiprofissional. Estas ações no município de Santo André foram corroborativas aos esforços da sociedade civil e o pleno desenvolvimento da mudança do modelo hospitalocêntrico
Resumo:
O artigo discute a adequação de aplicar a Resolução 196/961 do Conselho Nacional de Saúde - CNS, às pesquisas qualitativas em saúde, que se baseiam em paradigmas não positivistas. Nestas pesquisas, freqüentemente as decisões sobre a pesquisa são tomadas conjuntamente com a comunidade em estudo. Há a preocupação de favorecer a justiça e a mudança social. E, uma vez que a subjetividade pode ser considerada seu instrumento privilegiado, busca-se o balanço entre objetividade e subjetividade, e discute-se como superar a visão do pesquisador. Estudamos o âmbito de aplicação e a concepção de pesquisa presentes nas diretrizes éticas internacionais e brasileiras. Verificamos que elas adotam uma concepção positivista de pesquisa, que prevê: teste de hipótese, definição prévia de todos os procedimentos pelo pesquisador e neutralidade do pesquisador e do conhecimento produzido. Serão apresentadas algumas características das pesquisas qualitativas, as implicações éticas da maneira como a pesquisa qualitativa é concebida nos paradigmas não positivistas e um breve histórico dos documentos sobre ética em pesquisa. Concluímos que não é adequado analisar estas pesquisas com base nestes documentos e sugerimos a elaboração de diretrizes específicas
Resumo:
O trabalho apresenta um projeto de intervenção na realidade concreta das ações de Vigilância Sanitária, através da proposição de um roteiro para inspeção destinado a creches. Os objetivos específicos foram identificar os fundamentos jurídicos, técnico-científicos e sanitários que possam nortear a prática de inspeções sanitárias em creches; elaborar uma proposta de roteiro que permita um processo de análise mais explícito, objetivo e homogêneo e discutir a contribuição do instrumento proposto para a atividade de Vigilância Sanitária, com base na literatura científica pesquisada. Para a realização do trabalho foi feita uma revisão fundamentada em textos didáticos e normativos das áreas de educação e saúde, legislação sobre Vigilância Sanitária e Educação Infantil, outros roteiros já existentes e artigos da literatura científica sobre agravos à saúde em crianças que frequentam creches. O trabalho focaliza o conteúdo da legislação específica vigente e sua aplicabilidade na prática da inspeção sanitária em creches e baseia-se na Portaria - MS n. 321 de 26.05.1988. Este estudo apresenta um instrumento para avaliar a qualidade do atendimento nas creches sob o aspecto da promoção da saúde e sugere estudos posteriores de validação para o contexto, com a possível inclusão de um sistema de classificação para os padrões de conformidade, por meio de uma metodologia estatística
Resumo:
Background: Polypodium hydriforme is a parasite with an unusual life cycle and peculiar morphology, both of which have made its systematic position uncertain. Polypodium has traditionally been considered a cnidarian because it possesses nematocysts, the stinging structures characteristic of this phylum. However, recent molecular phylogenetic studies using 18S rDNA sequence data have challenged this interpretation, and have shown that Polypodium is a close relative to myxozoans and together they share a closer affinity to bilaterians than cnidarians. Due to the variable rates of 18S rDNA sequences, these results have been suggested to be an artifact of long-branch attraction ( LBA). A recent study, using multiple protein coding markers, shows that the myxozoan Buddenbrockia, is nested within cnidarians. Polypodium was not included in this study. To further investigate the phylogenetic placement of Polypodium, we have performed phylogenetic analyses of metazoans with 18S and partial 28S rDNA sequences in a large dataset that includes Polypodium and a comprehensive sampling of cnidarian taxa. Results: Analyses of a combined dataset of 18S and partial 28S sequences, and partial 28S alone, support the placement of Polypodium within Cnidaria. Removal of the long-branched myxozoans from the 18S dataset also results in Polypodium being nested within Cnidaria. These results suggest that previous reports showing that Polypodium and Myxozoa form a sister group to Bilateria were an artifact of long-branch attraction. Conclusion: By including 28S rDNA sequences and a comprehensive sampling of cnidarian taxa, we demonstrate that previously conflicting hypotheses concerning the phylogenetic placement of Polypodium can be reconciled. Specifically, the data presented provide evidence that Polypodium is indeed a cnidarian and is either the sister taxon to Hydrozoa, or part of the hydrozoan clade, Leptothecata. The former hypothesis is consistent with the traditional view that Polypodium should be placed in its own cnidarian class, Polypodiozoa.
Resumo:
The Neotropical ant genus Myrmelachista Roger comprises 69 described species and subspecies, and still is a poorly studied group. Larvae play a paramount role in colony nutrition in social hymenopterans and bear considerable value in the reconstruction of group phylogenies, however, they are generally neglected. Larvae of different instars of Myrmelachista catharinae Mayr (Hymenoptera: Formicidae) are herein described in detail by light and scanning electron microscopy. The number of larval instars was estimated as three based on the frequency distribution of maximum head capsule widths. The described larvae confirmed some traits typical of the genus: general shape of body and mandibles, general aspect and distribution of body hairs, and the number of sensilla on the palps and galea. Differently from other Myrmelachista larvae previously described, M. catharinae presented two distinct kinds of second instars, some additional types of body hairs, different number of antennal sensilla, and a distinct labrum shape. M. catharinae presented ten pairs of spiracles, which is the first record for this genus.
Resumo:
Gene clustering is a useful exploratory technique to group together genes with similar expression levels under distinct cell cycle phases or distinct conditions. It helps the biologist to identify potentially meaningful relationships between genes. In this study, we propose a clustering method based on multivariate normal mixture models, where the number of clusters is predicted via sequential hypothesis tests: at each step, the method considers a mixture model of m components (m = 2 in the first step) and tests if in fact it should be m - 1. If the hypothesis is rejected, m is increased and a new test is carried out. The method continues (increasing m) until the hypothesis is accepted. The theoretical core of the method is the full Bayesian significance test, an intuitive Bayesian approach, which needs no model complexity penalization nor positive probabilities for sharp hypotheses. Numerical experiments were based on a cDNA microarray dataset consisting of expression levels of 205 genes belonging to four functional categories, for 10 distinct strains of Saccharomyces cerevisiae. To analyze the method's sensitivity to data dimension, we performed principal components analysis on the original dataset and predicted the number of classes using 2 to 10 principal components. Compared to Mclust (model-based clustering), our method shows more consistent results.
Resumo:
It is well known that carbohydrate (CHO) supplementation can improve performance in endurance exercises through several mechanisms such as maintenance of glycemia and sparing endogenous glycogen as well as the possibility of a central nervous-system action. Some studies have emerged in recent years in order to test the hypothesis of ergogenic action via central nervous system. Recent studies have demonstrated that CHO mouth rinse can lead to improved performance of cyclists, and this may be associated with the activation of brain areas linked to motivation and reward. These findings have already been replicated in other endurance modalities, such as running. This alternative seems to be an attractive nutritional tool to improve endurance exercise performance.
Resumo:
We explored possible effects of negative covariation among finger forces in multifinger accurate force production tasks on the classical Fitts's speed-accuracy trade-off. Healthy subjects performed cyclic force changes between pairs of targets ""as quickly and accurately as possible."" Tasks with two force amplitudes and six ratics of force amplitude to target size were performed by each of the four fingers of the right hand and four finger combinations. There was a close to linear relation between movement time and the log-transformed ratio of target amplitude to target size across all finger combinations. There was a close to linear relation between standard deviation of force amplitude and movement time. There were no differences between the performance of either of the two ""radial"" fingers (index and middle) and the multifinger tasks. The ""ulnar"" fingers (little and ring) showed higher indices of variability and longer movement times as compared with both ""radial"" fingers and multifinger combinations. We conclude that potential effects of the negative covariation and also of the task-sharing across a set of fingers are counterbalanced by an increase in individual finger force variability in multifinger tasks as compared with single-finger tasks. The results speak in favor of a feed-forward model of multifinger synergies. They corroborate a hypothesis that multifinger synergies are created not to improve overall accuracy, but to allow the system larger flexibility, for example to deal with unexpected perturbations and concomitant tasks.
Resumo:
Background: With nearly 1,100 species, the fish family Characidae represents more than half of the species of Characiformes, and is a key component of Neotropical freshwater ecosystems. The composition, phylogeny, and classification of Characidae is currently uncertain, despite significant efforts based on analysis of morphological and molecular data. No consensus about the monophyly of this group or its position within the order Characiformes has been reached, challenged by the fact that many key studies to date have non-overlapping taxonomic representation and focus only on subsets of this diversity. Results: In the present study we propose a new definition of the family Characidae and a hypothesis of relationships for the Characiformes based on phylogenetic analysis of DNA sequences of two mitochondrial and three nuclear genes (4,680 base pairs). The sequences were obtained from 211 samples representing 166 genera distributed among all 18 recognized families in the order Characiformes, all 14 recognized subfamilies in the Characidae, plus 56 of the genera so far considered incertae sedis in the Characidae. The phylogeny obtained is robust, with most lineages significantly supported by posterior probabilities in Bayesian analysis, and high bootstrap values from maximum likelihood and parsimony analyses. Conclusion: A monophyletic assemblage strongly supported in all our phylogenetic analysis is herein defined as the Characidae and includes the characiform species lacking a supraorbital bone and with a derived position of the emergence of the hyoid artery from the anterior ceratohyal. To recognize this and several other monophyletic groups within characiforms we propose changes in the limits of several families to facilitate future studies in the Characiformes and particularly the Characidae. This work presents a new phylogenetic framework for a speciose and morphologically diverse group of freshwater fishes of significant ecological and evolutionary importance across the Neotropics and portions of Africa.
Resumo:
We analytically calculate the time-averaged electromagnetic energy stored inside a nondispersive magnetic isotropic cylinder that is obliquely irradiated by an electromagnetic plane wave. An expression for the optical-absorption efficiency in terms of the magnetic internal coefficients is also obtained. In the low absorption limit, we derive a relation between the normalized internal energy and the optical-absorption efficiency that is not affected by the magnetism and the incidence angle. This relation, indeed, seems to be independent of the shape of the scatterer. This universal aspect of the internal energy is connected to the transport velocity and consequently to the diffusion coefficient in the multiple scattering regime. Magnetism favors high internal energy for low size parameter cylinders, which leads to a low diffusion coefficient for electromagnetic propagation in 2D random media. (C) 2010 Optical Society of America
Resumo:
Background: Hexamerins are hemocyanin-derived proteins that have lost the ability to bind copper ions and transport oxygen; instead, they became storage proteins. The current study aimed to broaden our knowledge on the hexamerin genes found in the honey bee genome by exploring their structural characteristics, expression profiles, evolution, and functions in the life cycle of workers, drones and queens. Results: The hexamerin genes of the honey bee (hex 70a, hex 70b, hex 70c and hex 110) diverge considerably in structure, so that the overall amino acid identity shared among their deduced protein subunits varies from 30 to 42%. Bioinformatics search for motifs in the respective upstream control regions (UCRs) revealed six overrepresented motifs including a potential binding site for Ultraspiracle (Usp), a target of juvenile hormone (JH). The expression of these genes was induced by topical application of JH on worker larvae. The four genes are highly transcribed by the larval fat body, although with significant differences in transcript levels, but only hex 110 and hex 70a are re-induced in the adult fat body in a caste-and sex-specific fashion, workers showing the highest expression. Transcripts for hex 110, hex 70a and hex70b were detected in developing ovaries and testes, and hex 110 was highly transcribed in the ovaries of egg-laying queens. A phylogenetic analysis revealed that HEX 110 is located at the most basal position among the holometabola hexamerins, and like HEX 70a and HEX 70c, it shares potential orthology relationship with hexamerins from other hymenopteran species. Conclusions: Striking differences were found in the structure and developmental expression of the four hexamerin genes in the honey bee. The presence of a potential binding site for Usp in the respective 5' UCRs, and the results of experiments on JH level manipulation in vivo support the hypothesis of regulation by JH. Transcript levels and patterns in the fat body and gonads suggest that, in addition to their primary role in supplying amino acids for metamorphosis, hexamerins serve as storage proteins for gonad development, egg production, and to support foraging activity. A phylogenetic analysis including the four deduced hexamerins and related proteins revealed a complex pattern of evolution, with independent radiation in insect orders.
Resumo:
Stingless bees exhibit extraordinary variation in nest architecture within and among species. To test for phylogenetic association of behavioral traits for species of the Neotropical stingless bee genus Trigona s.s., a phylogenetic hypothesis was generated by combining sequence data of 24 taxa from one mitochondrial (16S rRNA) and four nuclear gene fragments (long-wavelength rhodopsin copy 1 (opsin), elongation factor-1 alpha copy F2, arginine kinase, and 28S rRNA). Fifteen characteristics of the nest architecture were coded and tested for phylogenetic association. Several characters have significant phylogenetic signal, including type of nesting substrate, nest construction material, and hemipterophily, the tending of hemipteroid insects in exchange for sugar excretions. Phylogenetic independent habits encountered in Trigona s.s. include coprophily and necrophagy.