1000 resultados para structure sociale
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Distinct genetic structure in populations of Chrysoperla externa (Hagen) (Neuroptera, Chrysopidae) shown by genetic markers ISSR and COI gene. Green lacewings are generalist predators, and the species Chrysoperla externa presents a great potential for use in biological control of agricultural pests due to its high predation and reproduction capacities, as well as its easy mass rearing in the laboratory. The adaptive success of a species is related to genetic variability, so that population genetic studies are extremely important in order to maximize success of the biological control. Thus, the present study used nuclear (Inter Simple Sequence Repeat - ISSR) and mitochondrial (Cytochrome Oxidase I - COI) molecular markers to estimate the genetic variability of 12 populations in the São Paulo State, Brazil, as well as the genetic relationships between populations. High levels of genetic diversity were observed for both markers, and the highest values of genetic diversity appear associated with municipalities that have the greatest areas of native vegetation. There was high haplotype sharing, and there was no correlation between the markers and the geographic distribution of the populations. The AMOVA indicated absence of genetic structure for the COI gene, suggesting that the sampled areas formed a single population unit. However, the great genetic differentiation among populations showed by ISSR demonstrates that these have been under differentiation after their expansion or may also reflect distinct dispersal behavior between males and females.
Effects of forest conversion on the assemblages' structure of aquatic insects in subtropical regions
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The effects of forest conversion to agricultural land uses on assemblages of aquatic insects were analyzed in subtropical streams. Organisms and environmental variables were collected in six low-order streams: three streams located in a forested area, and three in areas converted to agricultural land uses. We expected that the aquatic insects' assemblage attributes would be significantly affected by forest conversion, as well as by environmental variables. Streams in converted areas presented lower species richness, abundance and proportion of sensitive insect taxa. The ANOSIM test evidenced strong difference in EPT assemblage structure between streams of forested and converted areas. The ISA test evidenced several EPT genera with high specificity to streams in forested areas and only one genus related to streams in converted areas. Thus, the impacts of the conversion of forested area to agricultural land uses have significantly affected the EPT assemblages, while environmental variables were not affected. We suggest that the effects detected can be influenced by two processes related to vegetation cover: i) lower input of allochthonous material, and ii) increased input of fine sediments in streams draining converted areas.
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Myelination requires a massive increase in glial cell membrane synthesis. Here we demonstrate that the acute phase of myelin lipid synthesis is regulated by SREBP cleavage activation protein (SCAP), an activator of sterol regulatory element-binding proteins (SREBPs). Deletion of SCAP in Schwann cells led to a loss of SREBP-mediated gene expression, congenital hypomyelination and abnormal gait. Interestingly, aging SCAP mutant mice showed partial regain of function; they exhibited improved gait and produced small amounts of myelin indicating a slow SCAP-independent uptake of external lipids. Accordingly, extracellular lipoproteins promoted myelination by SCAP mutant Schwann cells. However, SCAP mutant myelin never reached normal thickness and had biophysical abnormalities concordant with abnormal lipid composition. These data demonstrate that SCAP mediated regulation of glial lipogenesis is key to the proper synthesis of myelin membrane. The described defects in SCAP mutant myelination provide new insights into the pathogenesis, and open new avenues for treatment strategies, of peripheral neuropathies associated with lipid metabolic disorders.
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Three phosphatidylinositol-3-kinase-related protein kinases implement cellular responses to DNA damage. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and ataxia-telangiectasia mutated respond primarily to DNA double-strand breaks (DSBs). Ataxia-telangiectasia and RAD3-related (ATR) signals the accumulation of replication protein A (RPA)-covered single-stranded DNA (ssDNA), which is caused by replication obstacles. Stalled replication intermediates can further degenerate and yield replication-associated DSBs. In this paper, we show that the juxtaposition of a double-stranded DNA end and a short ssDNA gap triggered robust activation of endogenous ATR and Chk1 in human cell-free extracts. This DNA damage signal depended on DNA-PKcs and ATR, which congregated onto gapped linear duplex DNA. DNA-PKcs primed ATR/Chk1 activation through DNA structure-specific phosphorylation of RPA32 and TopBP1. The synergistic activation of DNA-PKcs and ATR suggests that the two kinases combine to mount a prompt and specific response to replication-born DSBs.
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Although the Santiago variety of Cape Verdean Creole (CVC) has been the subject of numerous linguistic works, the second major variety of the language, i.e. the São Vicente variety of CVC (CVSV), has hardly been described. Nevertheless this lack of studies and given its striking differences, on all linguistic levels, from the variety of Santiago (CVST), the implicit explanation for such divergences, echoed for decades in the literature on CVC, has been the presumably decreolized character of CVSV. First, this study provides a comprehensive fieldwork-based synchronic description of CVSV major morpho-syntactic categories in the intent to document the variety. Second, it aims to place the study of CVSV within a broader scope of contact linguistics in the quest to explain its structure. Based on analyses of historical documents and studies, it reconstructs the sociohistorical scenario of the emergence and development of CVSV in the period of 1797- 1975. From the comparison of the current structures of CVSV and CVST, the examination of linguistic data in historical texts and the analysis of sociohistorical facts it becomes clear that the contemporary structure of CVSV stems from the contact-induced changes that occurred during the intensive language and dialect contact on the island of São Vicente in the early days of its settlement in the late 18th and ensuing early 19th century development, rather than from modern day pressure of Portuguese. Although this dissertation argues for multiple explanations rather than a single theory, by showing that processes such as languages shift among the first Portuguese settlers, L2 acquisition, migration of the Barlavento speakers and subsequent dialect leveling as well as language borrowing at a later stage were at stake, it demonstrates the usefulness of partial-restructuring model proposed by Holm (2004).
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ABSTRACT The Brazilian Atlantic Forest is one of the world's biodiversity hotspots, and is currently highly fragmented and disturbed due to human activities. Variation in environmental conditions in the Atlantic Forest can influence the distribution of species, which may show associations with some environmental features. Dung beetles (Coleoptera: Scarabaeinae) are insects that act in nutrient cycling via organic matter decomposition and have been used for monitoring environmental changes. The aim of this study is to identify associations between the spatial distribution of dung beetle species and Atlantic Forest structure. The spatial distribution of some dung beetle species was associated with structural forest features. The number of species among the sampling sites ranged widely, and few species were found in all remnant areas. Principal coordinates analysis indicated that species composition, abundance and biomass showed a spatially structured distribution, and these results were corroborated by permutational multivariate analysis of variance. The indicator value index and redundancy analysis showed an association of several dung beetle species with some explanatory environmental variables related to Atlantic Forest structure. This work demonstrated the existence of a spatially structured distribution of dung beetles, with significant associations between several species and forest structure in Atlantic Forest remnants from Southern Brazil.
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Purpose of review: An overview of recent advances in structural neuroimaging and their impact on movement disorders research is presented. Recent findings: Novel developments in computational neuroanatomy and improvements in magnetic resonance image quality have brought further insight into the pathophysiology of movement disorders. Sophisticated automated techniques allow for sensitive and reliable in-vivo differentiation of phenotype/genotype related traits and their interaction even at presymptomatic stages of disease. Summary: Voxel-based morphometry consistently demonstrates well defined patterns of brain structure changes in movement disorders. Advanced stages of idiopathic Parkinson's disease are characterized by grey matter volume decreases in basal ganglia. Depending on the presence of cognitive impairment, volume changes are reported in widespread cortical and limbic areas. Atypical Parkinsonian syndromes still pose a challenge for accurate morphometry-based classification, especially in early stages of disease progression. Essential tremor has been mainly associated with thalamic and cerebellar changes. Studies on preclinical Huntington's disease show progressive loss of tissue in the caudate and cortical thinning related to distinct motor and cognitive phenotypes. Basal ganglia volume in primary dystonia reveals an interaction between genotype and phenotype such that brain structure changes are modulated by the presence of symptoms under the influence of genetic factors. Tics in Tourette's syndrome correlate with brain structure changes in limbic, motor and associative fronto-striato-parietal circuits. Computational neuroanatomy provides useful tools for in-vivo assessment of brain structure in movement disorders, allowing for accurate classification in early clinical stages as well as for monitoring therapy effects and/or disease progression.
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(Résumé de l'ouvrage) La politique sociale concerne directement tous les habitants de ce pays à quelque titre qu'ils y séjournent. C'est une dimension majeure de l'organisation publique du pays. C'est aussi un système complexe pour les usagers et pour les professionnels engagés dans ce domaine. Ce dictionnaire qui traite de la politique sociale, mais aussi de l'action sociale peut intéresser les milieux les plus larges mais, en particulier, les élus, les professionnels de l'action sociale et sanitaire, les journalistes, les étudiants du secteur social et les responsables d'institutions. 380 pages - 850 termes analysés - 250 auteurs Importante bibliographie classée
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Amplified ribosomal DNA restriction analysis (ARDRA) is a simple method based on restriction endonuclease digestion of the amplified bacterial 16S rDNA. In this study we have evaluated the suitability of this method to detect differences in activated sludge bacterial communities fed on domestic or industrial wastewater, and subject to different operational conditions. The ability of ARDRA to detect these differences has been tested in modified Ludzack-Ettinger (MLE) configurations. Samples from three activated sludge wastewater treatment plants (WWTPs) with the MLE configuration were collected for both oxic and anoxic reactors, and ARDRA patterns using double enzyme digestions AluI+MspI were obtained. A matrix of Dice similarity coefficients was calculated and used to compare these restriction patterns. Differences in the community structure due to influent characteristics and temperature could be observed, but not between the oxic and anoxic reactors of each of the three MLE configurations. Other possible applications of ARDRA for detecting and monitoring changes in activated sludge systems are also discussed