1,240 research outputs found
A novel locus for autosomal recessive primary microcephaly (MCPH6) maps to 13q12.2
Key points:
âą Autosomal recessive primary microcephaly (MCPH) is a
genetic disorder in which an affected subject is born
with a head circumference >3 SD below the expected
mean and is mentally retarded.
âą We report a novel locus (MCPH6) mapped to chromosome
13q12.2 in a Brazilian family.
âą The minimal critical region spans 6 Mb between markers
AL139378GT17 and D13S1244 with a maximum
two point lod score of 6.25
USO DA TERRA DA SUB-BACIA HIDROGRĂFICA DO RIACHO LUNGA/AL.
O presente trabalho aborda o mapeamento do uso da terra na sub-bacia hidrogrĂĄfica do riacho Lunga/AL, contribuinte do mĂ©dio curso do rio Coruripe/AL. O levantamento de dados ocorreu atravĂ©s de pesquisa in locu, com informaçÔes sobre a influĂȘncia humana na regiĂŁo, onde predomina a pastagem, e cultivos de subsistĂȘncia, alĂ©m de grande impacto nas margens dos rios em decorrĂȘncia do uso intenso dessas ĂĄreas, por conseguinte foi feito o mapeamento caracterizando ou espacializando tais dados
Application of the zero-range potential model to positron annihilation on molecules
In this paper we use a zero-range potential (ZRP) method to model positron
interaction with molecules. This allows us to investigate the effect of
molecular vibrations on positron-molecule annihilation using the van der Waals
dimer Kr2 as an example. We also use the ZRP to explore positron binding to
polyatomics and examine the dependence of the binding energy on the size of the
molecule for alkanes. We find that a second bound state appears for a molecule
with ten carbons, similar to recent experimental evidence for such a state
emerging in alkanes with twelve carbons.Comment: 14 pages, 6 figures, to be published in Nuclear Instruments and
Methods
Alien reptiles on Mediterranean Islands : A model for invasion biogeography
Aim: The Mediterranean basin has a long history of interactions between humans and biota, with multiple ancient and recent introductions of alien species. Such a multitude of introductions makes it difficult to distinguish between alien and native species but provides an excellent opportunity to investigate factors related to introductions and long-term persistence of alien species. In this study, we combined genetic and distribution data to identify the factors promoting the presence of alien reptiles on islands, considering human-related, geographic and species features. Furthermore, we assessed whether the use of genetic evidence to identify alien species improves inference of the factors determining their distribution. Location: Mediterranean islands. Methods: We combined genetic data and distribution databases to obtain information on biological traits and on the native/alien status of reptiles on >900 Mediterranean islands, and we gathered data on geographic and human features of islands. We then used spatially explicit generalized additive mixed models to identify the factors associated with the establishment of alien reptiles. Results: Alien reptile populations are more frequent on islands far from the native range and with large human population. Alien populations of reptiles that are able to feed on plants are particularly frequent. Traditional data sources underestimate the frequency of alien reptiles on Mediterranean islands, and using genetic evidence to assess the status of populations provided a more complete picture of the factors associated with the presence of alien populations. Main conclusions: Humans are key drivers of the distribution of alien reptiles on Mediterranean islands, but the distributions are determined by a complex interplay between human activities, geographic factors and species features. Genetic data are essential for obtaining reliable biogeographic assessments of invasive species, particularly in systems with a long history of human influence
Kinin B1 receptor gene ablation affects hypothalamic CART production
A role for the kinin B1 receptor in energy-homeostatic processes was implicated by previous works. Notably the studies where kinin B1 receptor knockout mice (B1-/-) are observed to have impaired adiposity, impaired leptin and insulin production, lower feed efficiency, protection from liver steatosis and diet induced obesity when fed a high fat diet (HFD). More particularly, in a model where the B1 receptor is expressed exclusively in the adipose tissue, it rescues the plasma insulin concentration and the weight gain seen in wild type mice. Taking into consideration that leptin participates in the formation of hypothalamic nuclei, which modulate energy expenditure, and feeding behavior, we hypothesized that these brain regions could also be altered in B1-/- mice. We observed for the first time a difference in the gene expression pattern of CART (cocaine-and-amphetamine related transcript) in the LHA (lateral hypothalamic area) resulting from the deletion of the kinin B1 receptor gene. The correlation between CART expression in the LHA and the thwarting of diet-induced obesity corroborates independent correlations between CART and obesity. Further it seems to indicate that the mechanism underlying the 'lean' phenotype of B1-/- mice is not solely stemming from changes in peripheral tissues but may also receive contributions from changes in the hypothalamic machinery involved in energy homeostasis processes
Uso da adubação orgĂąnica e cobertura morta na cultura da calĂȘndula (Calendula officinalis L.).
A calĂȘndula representa fonte alternativa econĂŽmica principalmente para a agricultura familiar. O objetivo do presente trabalho foi avaliar os efeitos da adubação orgĂąnica e do uso da cobertura morta sobre a produção de biomassa e teor de flavonĂłides totais em plantas de calĂȘndula. O experimento foi realizado no Campus de Montes Claros da Universidade Federal de Minas Gerais, utilizando-se o delineamento em blocos casualizados em esquema fatorial 2x2x4 com quatro repetiçÔes: duas Ă©pocas de colheita, presença ou ausĂȘncia de cobertura morta e quatro doses de composto orgĂąnico (0, 30, 60 e 90 t ha-1). As maiores produçÔes de biomassa e flavonĂłides totais foram verificadas com o aumento das doses de composto orgĂąnico. Para os flavonĂłides totais o maior teor foi obtido na segunda colheita na presença de cobertura morta
Exciton Spin Dynamics in Semiconductor Quantum Wells
In this paper we will review Exciton Spin Dynamics in Semiconductor Quantum
Wells. The spin properties of excitons in nanostructures are determined by
their fine structure. We will mainly focus in this review on GaAs and InGaAs
quantum wells which are model systems.Comment: 55 pages, 27 figure
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