71 resultados para Heredity.
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Objective: analyze the prevalence of recurrent wheezing and its risk factors. Method: systematic literature review, guided by the research question “what is the prevalence of recurrent wheezing and its risk factors?”. The search was performed in the databases MedLine and LILACS, in April and May 2013. The inclusion criteria were: scientific study, fully available, published between 2002 and 2013, with free access. Results: wheezing presents a higher prevalence in developing countries, possibly due to poor socioeconomic conditions. Among its risk factors, we find heredity, mother’s education level, attendance of day nursery, smoking during pregnancy, breastfeeding for < 3 months, animals in the household of children, among others. Conclusion: in Latin America, the prevalence of wheezing shows to be high and the use of non-standardized instruments hampers its treatment.
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The genetic inheritance, beyond determining the regular features of all the live beings, can also be the cause of diseases, called as hereditary or genetic diseases. In the case of livestock, especially cattle, little genetic variation, by the use of the same sires for a long time, can facilitate the emergence of problems. In this study, we reviewed eight of the most important genetic diseases in cattle herds around the world, whose mutation has already been characterized. Some of these diseases are reported in Brazil, but there are few studies and articles on this subject, due to the difficulty of a definitive diagnosis, which often is only possible with the use of molecular biology techniques. The knowledge of the disorders and the correct diagnosis are essential to initiate an action plan aimed at eradicating them
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In epidemiological studies, when the data is collected by interview, it is of importance to analyse the reliability of the information. This study was carried out with the purpose of examining the self-agreement of mothers in answering questions about variables of interest in oral cleft researches on two different occasions. A sample of 91 mothers of oral cleft babies were interviewed on two different occasions. The capacity of giving the same answer to questions related to heredity, type of clefts, period of gestation of the mother and birthweight were studied. The statistics type kappa (k) and intraclass correlation coefficient (r) by point and by 95% of confidence interval were applied. The intra-observer agreement for the variables history of oral clefts in the family, type of cleft, period of gestation of the mother and birthweight of the newborn was, respectively, k=0.9492, k=1.0000, k=0.9281 and r=0.9996. We concluded that the background on oral cleft in the family history of patients with this anomaly is a variable with an excellent degree of reliability. Also, the information given by the mothers related to the period of gestation, type of the baby’s cleft and birthweight are reliable.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes.
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Two daughters of a nonconsanguineous couple are described. Both present mental retardation, epileptic seizures, congenital atrichia, histologically anomalous skin and abnormal EEG pattern. From a discussion of the literature on atrichia, the forms without involvement of teeth, nails and hidrosis, among which recessive inheritance prevails, are distinguished from each other. None of them coincide with the syndrome described here.
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Griffith's experiments regarding bacterial transformation Pneumococcus are regarded as essential when related to DNA/heredity recognition process. The aim of the current study is to assess the didac tic transposition of the concept of bacterial transformation since the Griffith's descriptions until its current approach on didactic books. We realized that the historical context and the relationship between bacterial transformation and DNA recognition as genetic material are poorly explored. The core of our paper is the historical approach of those exper iments. By considering the wide richness of the knowledge that is ranged on Griffith's experiments, we suggest a didactic transposition concerning bacterial transformation in the learning process, involving an integration of contents.
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Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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This paper is part of a broader investigation on Epistemology of Biology carried out by a group of researchers from Cascavel/PR. It involves studies and research about biological thought on subjects such as the growing of the concepts of gene, genotype and phenotype. The aim of this research was to gather the undergraduate students of Biological Sciences’ views about the role played by the inclusion of a historical episode in the study group as a trigger for epistemological discussions and didactic reflections. Firstly, the students received Johannsen’s article “The genotype conception of heredity, published in 1911 in the journal The American Naturalist, in which he proposed the concepts of genotype and phenotype, among other ones. After, there was a discussion held by group about the concepts proposed in the article taking into account the epistemological, historical and didactic aspects. Data collection occurred through the recording of the group discussions and individual interviews. The results suggest that the inclusion of this historical episode, enabled the participants to develop critical thinking through collective reflection on the meaning of biological knowledge in different contexts.