Gene-flow has been studied in this research from an analytical, theoretical, and practical angle. While simple models of restricted gene-flow are tractable analytically and can produce very accurate predictions when compared with the results of computer simulations, models of discrete populations with geographical structure and models of continuous populations need further research. In particular, models of isolation by distance in a continuum are very difficult to relate to concepts familiar to the population geneticist since the basic concept linking continuous populations to discrete ones, the neighbourhood size, is shown to be flawed. Inferring gene-flow from indirect methods implies obtaining unbiased estimators of quantities such as F-statistics. The framework for estimation presented in this research can be used to derive unbiased estimators in different situations, and can also help to clarify the underlying assumptions made when making these estimates. In particular the conditions are specified under which Nei and Chesser's (1983) and Weir and Cockerham's (1984) estimators are most appropriate. While analytical treatment of geographically structured populations is difficult, F-statistics can be used to unravel levels of genetic structuring in these populations. Methods are presented which yield ways of discriminating between samples taken within and among breeding units, a necessary distinction if levels of gene-flow are to be inferred. Calculations of pairwise Fat, even in continuous populations, provide a picture of the geography of gene-flow in the population investigated. The methods are applied to data sets of three species, Brassica oleracea ssp. oleracea, Beta vulgaris ssp. maritima and Nucella lapillus and lead to new insights in the population biology of these species.

Made available in DSpace on 2014-06-11T19:26:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-04-06Bitstream added on 2014-06-13T20:53:58Z : No. of bitstreams: 1 spenassatto_c_me_botib.pdf: 1377275 bytes, checksum: 6cf6a389dd380de975e39f9fc9268330 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O Aedes aegypti, culicídeo de hábitos diurnos, é originário do continente africano e está globalmente distribuído pelos trópicos em associação com as populações humanas. É considerado de grande importância epidemiológica por ser o principal vetor dos quatro sorotipos do vírus da dengue e da febre amarela. Uma das primeiras detecções da presença do mosquito no Estado de São Paulo aconteceu na década de 80 na cidade de Santos. Atualmente não há disponível nenhuma vacina ou medicamento eficiente contra a dengue, assim o controle da doença está restrito ao controle do vetor. Uma das alternativas de controle e entendimento das relações vetor-patógeno-homem se baseiam no desenvolvimento de ferramentas moleculares que utilizam técnicas baseadas em PCR, as quais têm possibilitado o estudo genético das populações do Ae. aegypti. Em tais estudos, vários marcadores foram envolvidos, tais como os SNPs (Single Nucleotide Polymorphisms) e marcadores mitocondriais. Nós desenvolvemos ensaios utilizando metodologia TaqMan® para o estudo genético populacional de duas populações do mosquito Aedes aegypti de cidades portuárias do Estado de São Paulo, utilizando nove marcadores SNPs. Verificamos que esta metodologia é reprodutível, rápida, de baixo custo e eficiente para estudos em larga escala. Pela análise AMOVA encontramos uma baixa, mas significativa diferenciação genética entre as populações do estudo (FST = 0,0324; P < 0,01), e uma alta taxa de migrantes por geração (8,72 entre as populações 2007 e 5,39 entre as populações 2008), indicando fluxo gênico entre as populações. A análise implementada no software Structure 2.3.1, evidenciou a existência de três clusters baseados em semelhanças genotípicas, distribuídos em dois grupos, confirmando uma moderada estruturação populacional. Verificamos através da análise de fragmentos... / Aedes aegypti, is a diurnal mosquito, originated from the African continent and is globally distributed through the tropics in association with human populations. It is considered of great epidemiological importance for being the main vector of the four serotypes of Dengue and Yellow Fever. One of the first detections of the presence of the mosquito in the State of São Paulo happened in the 80's, in the city of Santos. Currently there is no available vaccine or effective medicine against dengue fever, and disease control is restricted to vector control. An alternative to control and understanding of vectorpathogen- man relationships are based on the development of molecular tools that use PCR-based techniques, which have enabled the genetic study of populations of Ae. aegypti. In such studies, several markers were involved, such as SNPs (Single Nucleotide Polymorphisms) and mitochondrial ones. We have developed assays using TaqMan® methodology for population genetic studies of two populations of Aedes aegypti from the port cities of São Paulo, using nine SNPs markers. We found that this methodology is reproducible, fast, inexpensive and efficient for large-scale studies. AMOVA analysis found a low but significant genetic differentiation between the studied populations (FST = 0.0324, P <0.01), and a high rate of migrants per generation (8.72 among populations in 2007 and 5.39 among populations in 2008), indicating gene flow between populations. The analysis implemented in software Structure 2.3.1, revealed the existence of three clusters based on genotypic similarities, divided into two groups, confirming a moderate population structure. We verified through the analysis of the mitochondrial gene fragments NADH dehydrogenase subunit 4 (ND4) a high genetic differentiation between the two study populations (FST = 0.18034, P <0.01), and a rate of migrants per generation considered high... (Complete abstract click electronic access below)

Orientador: Alberto Ferreira Amorim / Banca: Otto Bismarck Fazzano Gadig / Banca: Roberto Goitein / Banca: Emygdio Moreira Filho / Banca: Marcelo R. de Carvalho / Resumo: O presente trabalho visa gerar informações básicas sobre a ecologia e a situação populacional do tubarão-cabeça-de-cesto Carcharhinus perezi, lambarú Ginglymostoma cirratum e tubarão-limão Negaprion brevirostris no Arquipélago de Fernando de Noronha, com ênfase na primeira, por ser numericamente dominante. Utilizou-se a combinação de técnicas de marcação e recaptura e de telemetria ultra-sônica para fornecer informações sobre: estrutura populacional, distribuição espacial dos tubarões e de suas áreas de berçário, época de parto, padrões de movimentação e de utilização do hábitat. Amostras de sangue foram analisadas para caracterização sorológica das espécies. Foi implantado um programa de conscientização e educação sobre a necessidade de conservação dos tubarões, e realizou-se um curso de capacitação em Educação Ambiental para os professores do ensino médio e fundamental. A plataforma insular do arquipélago é utilizada como área de parto e de crescimento de jovens pelas três espécies de tubarões. Carcharhinus perezi apresenta maior segregação espacial por tamanho. Não ocorre segregação espacial em Ginglymostoma cirratum e Negaprion brevirostris pois foram observados indivíduos neonatos, jovens e adultos freqüentando a região próxima à linha costeira do arquipélago. Os tubarões utilizam com menor freqüência o trecho da Área de Proteção Ambiental (APA) do arquipélago, o que possivelmente está relacionado à intensificação da utilização humana e a indícios de empobrecimento biológico da região nos últimos anos. O monitoramento por telemetria mostra que: os tubarões jovens são residentes em trechos específicos do arquipélago; eles podem ser ativos a qualquer horário do dia, mas os maiores espaços de atividade e deslocamentos ocorrem à noite; aparentemente não existem variações sazonais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of the present study is to provide basic data on the ecology and population status of the reef-shark Carcharhinus perezi, nurse-shark Ginglymostoma cirratum and lemon-shark Negaprion brevirostris at Fernando de Noronha archipelago, with special reference to Carcharhinus perezi, due to its numerical dominance. A combination of mark and recapture and ultrasonic telemetry methods were used to gather data on: the population structure, spatial distribution of the sharks, location of the nursery grounds, parturition time, patterns of movement and habitat use. Blood samples were analyzed for a serological characterization of the species. An educational program was established to increase the community awareness about shark conservation, and a capacitating course on Environmental Education was offered to teachers of the local school. The archipelago’s insular shelf is used as a parturition and growing ground for young sharks of the three species. Carcharhinus perezi shows size segregation. Size segregation was not observed in Ginglymostoma cirratum and Negaprion brevirostris, and neonate, young and adult sharks of these species were observed to frequent shallow waters of the archipelago. Sharks rarely frequent the archipelago’s Environmental Protection Area (EPA), which is probably related to an intensification of human use and evidences of biological impoverishment of this site in recent years. The telemetry monitoring shows that: the young sharks are resident and present site fidelity to specific portions of the archipelago; they may be active at any time of the day, but the larger activity spaces and excursions occur at night; apparently there is no seasonal variation in activity spaces and habitat use; and larger sharks have more extensive activity spaces. The main problems for the management and conservation of the sharks are:... (Complete abstract click electronic access below) / Doutor

Human biomonitoring aims to measure the amount of certain substances in all aspects of the environment, how much of this that reach humans and in what way, and finally how this affects our health. In all aspects of this process lays challenges that must be overcome. When measuring substances in the environment, one must make sure that one is measuring the biomarker which gives the most precise results according to what one seeks to find. Dependent on the biomarker in question, multiple factors can potentially affect the measurements. When the most suitable biomarker has been found, one must make sure that all possible sources are located and taken into consideration, in order to provide a sufficient exposure assessment. The next challenge is to gather accurate epidemiologic data, and link this to the exposure in question, and make a reliable risk assessment. As the examples in this paper highlights, within each step are challenges, and possible limitations. For most substances, there are data gaps and incomplete understanding. There is now much work done globally, on how to further improve the process. Based on today's experiences and knowledge, new guidelines are put down. In Europe there was recently launched a program, that will coordinate the cooperation between the member states. Though it is already a...

In 1983 the Jamaican Parliament officially endorsed a National Population Policy which made the island the first in the Caribbean region to formulate such a policy. The Population Policy defined Jamaica's accelerating population as a negative constraint on the country's national development. One of the aims therefore, of the Policy was the introduction of replacement fertility i.e. a two child family. This was stipulated as a prerequisite to limit Jamaica's population growth. In an effort to disseminate the message of the two child family three mass media campaigns were conducted in the nineteen eighties. This thesis examines the efficacy of this replacement fertility campaign strategy in Jamaica's national development. The campaign's efficacy will be examined on the basis of its conceptualisation and implementation. This thesis constructs the argument that firstly, the conceptualisation of the media campaign was based on academically discredited views and assumptions on the role of the media in development. This position is substantiated in two ways. Firstly, through a semiotic analysis of the advertising campaign which revealed the implicit level of expectations concerning the campaign as well as the media's role in development. Secondly, through interviews with campaign planners and policy makers which disclosed the explicit expectations regarding the media and the campaign's function in development. It is argued that the ideological nature of the campaign's mythic structure, deciphered through the semiotic analysis, implies a role for the media in development which is consistent with the views of communication scholars who were advocates of the currently discredited Modernisation based model of communication in national development. An analysis of interviews with the campaign planners and policymakers demonstrates that their expressed views on the role of the media in development are identifiable with assumptions on this role inherent in the Modernisation paradigm. The thesis argues secondly, that the misinformed criteria and expectations directing the campaign are further reinforced by several features of the campaign design and implementation. It is shown that certain principles and practices of campaign design such as audience research, pretesting and interpersonal communication, which are academically proven ingredients of successful campaigns, were neglected in the campaign's construction. This calls into question the integrity of the campaign as a mechanism of social intervention. Further challenges to the campaign's efficacy are raised by findings from a social survey among the target group. This survey sought to assess the audience's view on the two child family; patterns of mass media use; sources of information on family planning; the credibility of these sources compared with the credibility of the media; contraceptive use and information needs on contraception.

No description available.

Patterns of genetic connectivity can help answer key questions about the evolutionary ecology of fishes. This knowledge is particularly useful when considering the management and conservation of species that are impacted by fisheries. Population connectivity in ocean habitats is heavily influenced by environmental and oceanographic factors. These factors can lead to strong genetic differences within populations, causing fragmentation into smaller subpopulations. The Red Sea exhibits pronounced oceanographic gradients in temperature, chlorophyll, and salinity, which have been assessed in various species’ populations and which have been found to have potential impacts on gene flow. The Red Sea also features strong cyclonic and anticyclonic eddies that may facilitate, or possibly inhibit, the transport of larvae throughout the Red Sea, potentially influencing gene flow themselves. The ability of oceanographic factors like eddies to structure wild fisheries populations in this region has yet to be fully determined. To address this, the genetic composition of two of the most highly fished species, (Plectropomus areolatus and Plectropomus pessuliferus marisrubri), in the Red Sea were evaluated utilizing genetic markers (polymorphic microsatellite loci). Samples from three geographically separate regions along the Saudi Arabian Red Sea coastline, as well as from Sudan, were analyzed to address latitudinal and cross-sea connectivity. I was able to determine that little genetic differentiation exists within Plectropomus species across all regions of the Red Sea, indicating high gene flow for these species throughout. These findings highlight the ability of currents and eddies to transport larvae along and across the Red Sea. The results from this study also indicate that a single population of P. areolatus and a single population of P. pessuliferus marisrubri occurs in the Red Sea. The high degree of genetic flow suggests that each species should be managed as individual units. This study presents a plausible avenue for buffering the effects of overfishing currently occurring in Saudi Arabia; Saudi Arabian fish subpopulations may be reseeded by the Sudanese subpopulations.

No description available.

No description available.

Abstract A population-based study to investigate the epidemiological, genetic and clinical features of neurofibromatoses (NF) in Northern Finland was carried out between 1989–1996. The area concerned was that served by Oulu University Hospital, with a total population of 733 037. A total of 197 patients with neurofibromatosis type 1 (NF1), five with neurofibromatosis type 2 (NF2) and eight with segmental neurofibromatosis (NF5) fulfilling the diagnostic criteria were identified among several hundred patients examined on account of a possible NF diagnosis. The 197 NF1 patients came from 119 families. 77 of these cases were sporadic, 117 familial, and three were mothers of children suffering from NF1 who were themselves diagnosed as having segmental NF. The male/female ratio was 0.93 (95 males and 105 females). The geographical distribution of the patients roughly corresponded to that of the general population in the area. The overall prevalence of NF1 was 23/100 000, with a peak prevalence of 34/100 000 in the age group 10 to 19 years. The overall birth incidence of NF1 was estimated to be 27/100 000, with the highest figure, 37/100 000, recorded in the six-year period 1990–1995. The mean age at the time of diagnosis was 20 ± 16 years in the whole population and 6 ± 4 years in the children born in the 1980's. A new mutation was suspected in 49% of the NF1 cases (96/197), and a mutation rate of 4.37 ± 0.72 × 10-5 was obtained for the period 1960–1995. The relative fitness of the NF1 patients was 0.48, being reduced more in the affected males (0.24) than in the females (0.72). The mean maternal and paternal ages of the sporadic patients were 30 ± 6 and 33 ± 6 years, respectively, which is significantly higher than in the general population. Two cases with a deletion of the NF1 gene were identified, one encompassing the loci from EVI-20 to INT-38 and the other the INT-27 locus, representing 3% of the 66 cases analysed. In seven familial cases the parental origin of the new mutation could be verified and linkage studies showed that the oldest affected individual in the family had inherited the mutation from the father in 6/7 cases. In one family seven members in three generations were affected with a rare spinal neurofibromatosis, and a linkage to the NF1 gene was shown. Of these seven patients, four are included among the 197 studied here while the other three lived outside the area. The diagnostic features of the 164 NF1 patients aged from three months to 73 years who were examined clinically included café au lait spots (CLS) in 96% of cases, freckles in 87%, neurofibromas in 69%, plexiform neurofibromas in 20%, Lisch nodules in 70%, optic glioma (asymptomatic) in 20% and pseudarthrosis in 3%. 56% of the cases had an affected first degree relative. A plexiform neurofibroma was diagnosed in 33 individuals and this became a malignant peripheral nerve sheath tumour(MPNST) during the seven years of monitoring in 15% of cases (5/33). Hyperintense T2 lesions in a MRI scan of the brain were found in 94% of the children under the age of six years who had had such a scan (n = 17) and in 84% of those under 16 years (n = 50). Symptoms related to NF1 which needed medical intervention, rehabilitation or follow-up were diagnosed in about 2/3 of the cases, and in 38% of cases such medical problems of this kind had been treated before NF1 was actually diagnosed. All these findings emphasise the need for a multidisciplinary approach to the follow-up of neurofibromatoses.