3 resultados para fragmentation pattern
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
Extensive studies using molecular markers on butterflies have shown how a highly fragmented landscape may result in the reduction of gene flow among patches of habitat and, consequently, increase genetic differentiation among populations. However, little is known about Heliconius geographical structure and the effects of fragmentation on the connectivity of populations. Furthermore, findings on the effects of the population structure on the dynamics of mimicry evolution in Heliconius butterflies need to be tested in H. erato and H. melpomene specimens found in other locations other than Central and northern South Americas. For the present study, we had two motivations: (1) compare the population structure of H. erato and H. melpomene given the highly fragmented Brazil s Atlantic Forest habitat; and (2) studying population structure of co-mimics could give us insights into the dynamics of mimicry evolution. For this, we analysed the spatial structure and connectivity of eight populations of Heliconius butterflies, in a total of 137 H. erato specimens and 145 H. melpomene specimens, using nine microsatellites loci, 1144 AFLPs markers and 282 mitochondrial DNA sequences. In general, both species exhibited evidence of population subdivision but no isolation by distance indicating some extent of genetic differentiation among populations. Contrary to Kronforst & Gilbert s (2008) Costa Rican Heliconius, H. melpomene exhibited more genetic differentiation than H. erato based on nuclear markers. However, for mitochondrial DNA, H. erato populations showed more genetic differentiation than H. melpomene. Our results corroborate to other studies on Heliconius butterflies concerning the pronounced population subdivision and local genetic drift found in this genus. Nevertheless, the pattern of this differentiation varies significantly from the pattern found in studies conducted in Central America, where H. erato is generally more differentiated and structured than H. melpomene, based on nuclear markers. This different pattern may reflect different evolutionary histories of Heliconius species in Northeastern Brazil s Atlantic Forest
Resumo:
It is known that sleep plays an important role in the process of motor learning. Recent studies have shown that the presence of sleep between training a motor task and retention test promotes a learning task so than the presence of only awake between training and testing. These findings also have been reported in stroke patients, however, there are few studies that investigate the results of this relationship on the functionality itself in this population. The objective of this study was to evaluate the relationship between functionality and sleep in patients in the chronic stage of stroke. A cross-sectional observational study was conducted. The sample was composed of 30 stroke individuals in chronic phase, between 6 and 60 months after injury and aged between 55 and 75 years. The volunteers were initially evaluated for clinical data of disease and personal history, severity of stroke, through the National Institute of Health Stroke Scale, and mental status, the Mini-Mental State Examination. Sleep assessment tools were Pittsburgh Sleep Quality Index, the Questionnaire of Horne and Ostberg, Epworth Sleepiness Scale, the Berlin questionnaire and actigraphy, which measures were: real time of sleep, waking after sleep onset, percentage of waking after sleep onset, sleep efficiency, sleep latency, sleep fragmentation index, mean activity score. Other actigraphy measures were intraday variability, stability interdiária, a 5-hour period with minimum level of activity (L5) and 10-hour period with maximum activity (M10), obtained to evaluate the activity-rest rhythm. The Functional Independence Measure (FIM) and the Berg Balance Scale (BBS) were the instruments used to evaluate the functional status of participants. The Spearman correlation coefficient and comparison tests (Student's t and Mann-Whitney) were used to analyze the relationship of sleep assessment tools and rest-activity rhythm to measures of functional assessment. The SPSS 16.0 was used for analysis, adopting a significance level of 5%. The main results observed were a negative correlation between sleepiness and balance and a negative correlation between the level of activity (M10) and sleep fragmentation. No measurement of sleep or rhythm was associated with functional independence measure. These findings suggest that there may be an association between sleepiness and xii balance in patients in the chronic stage of stroke, and that obtaining a higher level of activity may be associated with a better sleep pattern and rhythm more stable and less fragmented. Future studies should evaluate the cause-effect relationship between these parameters
Resumo:
The process of urbanization of Natal city has been going in the last years by importants changes, mainly, because we can observe the development of a new kind of housing: the horizontal closed condominiums, from 1995 began to expand quickly on the city. In this way, the present study has as objective analyse the expansion of the horizontal closed condominiums on the urban area of Natal. Emphasizing the sociogeographic changes that these ventures engender. For this, we have done a research that was based on quantitative procedures, however, preferring a qualitative approach. So, data were gathered from sources and procedures: the first, we performed a literature search and document on issues related to the relevant issues in libraries, public and privates institutions; The second, in accordance with the procedures, or the production of informations, performed enterview and implemetation of questionnaires with key stakeholders involved with the expansion of horizontal condominiums in Natal. Within this perspective, our research showed that the expansion of demand in the city, the existence of volume of land in areas suitable for the production building, the formation of capital property, the appearance of new points of modern consumption, the actions of the state and the low cost of production of these enterprises, are factors that have been decisive in the expansion of the horizontal condominiums in Natal. Also, we can observe that the process of production of the urban space from the horizontal condominiums comes in providing the redefinition of land use in areas that appear, because they expand into outlying areas of Natal, changes in its structure and its pattern of socio segregation, observing that the condominiums put the diferents social groups living side by side, but not mantaining relationships among them, the emergence of spaces to homogenization, the fragmentation of the urbanization, the privatization of the city and several environmental problems. In short, we believe that the horizontal expansion of condominiums is enabling a number of social changes to Natal city