Consistência hidrológica de modelos digitais de elevação (MDE) para definição da rede de drenagem na sub-bacia do horto florestal Terra Dura, Eldorado do Sul, RS

O desenvolvimento da erosão hídrica ocorre em resposta ao modo como a água se move através e sobre uma determinada paisagem. O modelo digital de elevação (MDE) deve, portanto, ser o mais preciso possível, uma vez que constitui a base para a análise do relevo. Este trabalho teve como objetivo definir um modelo digital de elevação hidrologicamente consistente (MDEHC) e o método de direção de fluxo mais adequado para a definição da rede de drenagem na sub-bacia do horto florestal Terra Dura, município de Eldorado do Sul, RS. Foram testados os modelos gerados com os interpoladores Topogrid e redes triangulares irregulares (Triangulated Irregular Network -TIN) linear (TIN L) e TIN natural neighbor (TIN NN). A qualidade em relação às análises hidrológicas foi avaliada por meio da comparação das curvas de nível geradas pelos modelos testados com as curvas originais da sub-bacia (escala 1:10.000); da avaliação da quantidade de áreas planas; e da comparação da drenagem gerada pelos modelos a partir dos métodos de direção de fluxo Deterministic (D8) e Deterministic infinity (D∞ ou D infinito) com a drenagem original. Entre os modelos avaliados, o Topogrid apresentou maior consistência hidrológica, verificada na melhor continuidade das curvas de nível (menos arestas) e maior detalhamento da área de drenagem e divisores, acarretando menor quantidade de áreas planas e caminhos de fluxo mais detalhados, independentemente do método de direção de fluxo utilizado. Em relação à rede de drenagem, o método distribuído D∞ obteve melhor desempenho na descrição dos caminhos de fluxo, comparado ao método de direção única D8. O MDEHC Topogrid associado ao método D∞ proporcionou a identificação mais precisa dos caminhos preferenciais do fluxo que formam a rede de drenagem.

Group 4: Career development for diverse and underserved populations

Globalization and diverse populations due to migration imply that counselors are expected to deliver career services to populations from a large array of cultural settings. Moreover, individuals belonging to minority or non-dominant groups may be underserved or misserved, thus decreasing their chances of finding employment opportunities through career counseling. To develop specific interventions minority or non-dominant groups, it seems important to understand their strength and weaknesses. These strengths and weaknesses will be presented in terms of risk and resilience factors, such as low future orientation and social support respectively. In the last two decades, several authors have made contributions to adapt and improve career services in order to best meet these minority groups' needs. A review of this literature identified thirteen keys to effective practice. For example, one key is to take responsibility for one's own biases and prejudices. Nonetheless, some underserved groups remain difficult to identify. Comparing some basic national demographic data with data from our counseling centers may be helpful in this context in identifying specific groups and assessing needs. One solution, in order to promote social justice across (all) cultural groups, is to encourage multiculturalism in both career counseling and society as a whole. A more inclusive society would allow each person in a minority or non-dominant group to contribute more effectively to the development and growth of this society.

Comparing connectomes across subjects and populations at different scales.

Brain connectivity can be represented by a network that enables the comparison of the different patterns of structural and functional connectivity among individuals. In the literature, two levels of statistical analysis have been considered in comparing brain connectivity across groups and subjects: 1) the global comparison where a single measure that summarizes the information of each brain is used in a statistical test; 2) the local analysis where a single test is performed either for each node/connection which implies a multiplicity correction, or for each group of nodes/connections where each subset is summarized by one single test in order to reduce the number of tests to avoid a penalizing multiplicity correction. We comment on the different levels of analysis and present some methods that have been proposed at each scale. We highlight as well the possible factors that could influence the statistical results and the questions that have to be addressed in such an analysis.

HIV disclosure and nondisclosure among migrant women from sub-Saharan Africa living in Switzerland.

No study to date has focused specifically on the reasons for and against disclosure of HIV-positive status among sub-Saharan migrant women. Thirty HIV-positive women from 11 sub-Saharan countries living in French-speaking Switzerland participated in semi-structured individual interviews. The reasons women reported for disclosure or nondisclosure of their HIV serostatus were classified into three categories: social, medical, and ethical. The women identified the stigma associated with HIV as a major social reason for nondisclosure. However, this study identifies new trends related to disclosure for medical and ethical reasons. Being undetectable played an important role in the life of sub-Saharan migrant women, and analysis revealed their medical reasons for both disclosure and nondisclosure. Disclosure to new sexual partners occurred when women had a more positive perception about HIV and when they believed themselves to be in a long-term relationship. Women reported nondisclosure to family members when they did not need help outside the support provided by the medical and social fields. The results on ethical reasons suggested that challenging stigma was a reason for disclosure. Since the women' perceptions on HIV changed when they came to see it as a chronic disease, disclosure occurred in an attempt to normalize life with HIV in their communities in migration and to challenge racism and discrimination. Our findings can help health providers better understand the communication needs of sub-Saharan migrant women with respect to HIV/AIDS and sexuality and offer them adequate disclosure advice that takes into account migration and gender issues.

Vortex state and effect of anisotropy in sub-100 nm magnetic nanodots

Magnetic properties of Fe nanodots are simulated using a scaling technique and Monte Carlo method, in good agreement with experimental results. For the 20-nm-thick dots with diameters larger than 60¿nm, the magnetization reversal via vortex state is observed. The role of magnetic interaction between dots in arrays in the reversal process is studied as a function of nanometric center-to-center distance. When this distance is more than twice the dot diameter, the interaction can be neglected and the magnetic properties of the entire array are determined by the magnetic configuration of the individual dots. The effect of crystalline anisotropy on the vortex state is investigated. For arrays of noninteracting dots, the anisotropy strongly affects the vortex nucleation field and coercivity, and only slightly affects the vortex annihilation field

Adaptive diversity in heterogeneous environments for populations regulated by a mixture of soft and hard selection

The stable co-existence of two haploid genotypes or two species is studied in a spatially heterogeneous environment submitted to a mixture of soft selection (within-patch regulation) and hard selection (outside-patch regulation) and where two kinds of resource are available. This is analysed both at an ecological time-scale (short term) and at an evolutionary time-scale (long term). At an ecological scale, we show that co-existence is very unlikely if the two competitors are symmetrical specialists exploiting different resources. In this case, the most favourable conditions are met when the two resources are equally available, a situation that should favour generalists at an evolutionary scale. Alternatively, low within-patch density dependence (soft selection) enhances the co-existence between two slightly different specialists of the most available resource. This results from the opposing forces that are acting in hard and soft regulation modes. In the case of unbalanced accessibility to the two resources, hard selection favours the most specialized genotype, whereas soft selection strongly favours the less specialized one. Our results suggest that competition for different resources may be difficult to demonstrate in the wild even when it is a key factor in the maintenance of adaptive diversity. At an evolutionary scale, a monomorphic invasive evolutionarily stable strategy (ESS) always exists. When a linear trade-off exists between survival in one habitat versus that in another, this ESS lies between an absolute adjustment of survival to niche size (for mainly soft-regulated populations) and absolute survival (specialization) in a single niche (for mainly hard-regulated populations). This suggests that environments in agreement with the assumptions of such models should lead to an absence of adaptive variation in the long term.

Distribution of the transposable elements bilbo and gypsy in original and colonizing populations of Drosophila subobscura

Background: Transposable elements (TEs) constitute a substantial amount of all eukaryotic genomes. They induce an important proportion of deleterious mutations by insertion into genes or gene regulatory regions. However, their mutational capabilities are not always adverse but can contribute to the genetic diversity and evolution of organisms. Knowledge of their distribution and activity in the genomes of populations under different environmental and demographic regimes, is important to understand their role in species evolution. In this work we study the chromosomaldistribution of two TEs, gypsy and bilbo, in original and colonizing populations of Drosophilasubobscura to reveal the putative effect of colonization on their insertion profile.Results: Chromosomal frequency distribution of two TEs in one original and three colonizingpopulations of D. subobscura, is different. Whereas the original population shows a low insertionfrequency in most TE sites, colonizing populations have a mixture of high (frequency ¿ 10%) andlow insertion sites for both TEs. Most highly occupied sites are coincident among colonizingpopulations and some of them are correlated to chromosomal arrangements. Comparisons of TEcopy number between the X chromosome and autosomes show that gypsy occupancy seems to becontrolled by negative selection, but bilbo one does not. Conclusion: These results are in accordance that TEs in Drosophila subobscura colonizing populations are submitted to a founder effect followed by genetic drift as a consequence of colonization. This would explain the high insertion frequencies of bilbo and gypsy in coincident sites of colonizing populations. High occupancy sites would represent insertion events prior to colonization. Sites of low frequency would be insertions that occurred after colonization and/orcopies from the original population whose frequency is decreasing in colonizing populations. Thiswork is a pioneer attempt to explain the chromosomal distribution of TEs in a colonizing specieswith high inversion polymorphism to reveal the putative effect of arrangements in TE insertionprofiles. In general no associations between arrangements and TE have been found, except in a fewcases where the association is very strong. Alternatively, founder drift effects, seem to play aleading role in TE genome distribution in colonizing populations.

Different behaviour of mouse-human chimeric antibody F(ab')2 fragments of IgG1, IgG2 and IgG4 sub-class in vivo.

Mouse-human chimeric monoclonal antibodies (MAbs) of 3 different human IgG sub-classes directed against carcinoembryonic antigen (CEA) have been produced in SP-0 cells transfected with genomic chimeric DNA. F(ab')2 fragments were obtained by pepsin digestion of the purified chimeric MAbs of human IgG1, IgG2 and IgG4 sub-class and of parental mouse MAb IgG1. The 4 F(ab')2 fragments exhibit similar molecular weight by SDS-PAGE. They were labelled with 125I or 131I and high binding (80 to 87%) to purified unsolubilized CEA was observed. In vivo, double labelling experiments indicate that the longest biological half-life and the highest tumour-localization capacity is obtained with F(ab')2 from chimeric MAb of human IgG2 sub-class, whereas F(ab')2 from chimeric MAb IgG4 give very low values for these 2 parameters. F(ab')2 from chimeric MAb IgG1 and from parental mouse MAb yield intermediate results in vivo. Our findings should help to select the appropriate human IgG sub-class to produce chimeric or reshaped MAb F(ab')2 to be used for tumour detection by immunoscintigraphy and for radioimmunotherapy.

O-chromosome lethal frequencies in Serbian and Montenegrin Drosophila subobscura populations

Lethal chromosomal frequencies were obtained from three Drosophila subobscura samples from the Mt. Avala (Serbia) population in September 2003 (0.218), June 2004 (0.204) and September 2004 (0.250). These values and those from other Balkan populations studied previously (Petnica, Kamariste, Zanjic and Djerdap) were used to analyze the possible effect of population, year, month and altitude above sea level on lethal chromosomal frequencies. According to ANOVAS no effect were observed. Furthermore, the lethal frequencies of the Balkan populations did not vary according to latitude. This is probably due to the relative proximity and high gene flow between these populations. From a joint study of all the Palearctic D. subobscura populations so far analyzed, it can be deduced that the Balkan populations are located in the central area of the species distribution. Finally, it seems that lethal chromosomal frequencies are a consequence of the genetic structure of the populations.