Os aspectos da pesca do espada, Trichiurus lepturus (Linnaeus, 1758) (Trichiuridae), foram descritos e analisados para as artes de pesca artesanal de linha-de-mão em Arraial do Cabo (RJ) e cerco flutuante em Porto Belo (SC), e da pesca comercial de arrasto de fundo com parelhas na costa de São Paulo. Verificaram-se tendências crescentes na produção da espécie, principalmente na pesca artesanal. Foram utilizados marcadores moleculares tipo RAPD para analisar a estrutura genético-populacional da espécie com exemplares de Belém (PA), Natal (RN), Arraial do Cabo (RJ), Guarujá (SP), Porto Belo (SC) e Rio Grande (RS), evidenciando-se uma população distinta em Belém, enquanto as demais não apresentaram estruturação definida. A dinâmica de populações foi analisada para exemplares de Arraial do Cabo, São Paulo e Porto Belo, coletados mensalmente de janeiro/2002 a julho/2003. A desova da espécie é parcelada com período reprodutivo ocorrendo do verão ao início do inverno. As fêmeas maduras migram para a plataforma encontrando-se com os machos maduros que ali permanecem, retornando à costa após a desova. O comprimento médio de primeira maturação sexual variou de 647 a 670mm (Lt) para fêmeas, e de 526 a 650mm para machos. As estimativas dos parâmetros de crescimento foram as seguintes: para fêmeas Loo de 1740 a 2010mm; k de 0,12 a 0,15/ano e t0 de -1,642 a -2,517 anos; para machos Loo de 1373 a 1580mm; k de 0,17 a 0.25/ano e t0 de -1,662 a -1,866 anos. A longevidade foi cerca de 14 anos. As taxas de mortalidade natural variaram de 0,20 a 0,29/ano. O modelo de rendimento relativo por recruta indicou que as taxas de mortalidade por pesca do espada estão próximas ou já ultrapassam os limites do rendimento máximo sustentável. / The fishery aspects of the cutlassfish, Trichiurus lepturus (Linnaeus, 1758) (Trichiuridae), were analyzed for the artisanal fishery of line and hook of Arraial do Cabo (RJ) and floating encirclement of Porto Belo (SC), and of the commercial paired bottom trawlers in the coast of São Paulo. Tendencies in increasing yields were detected, mainly in the artisanal fishery. RAPD markers techniques were employed in order to analyze the genetic-population structure of the cutlassfish from Belém (PA), Natal (RN), Arraial do Cabo (RJ), Guarujá (SP), Porto Belo (SC) and Rio Grande (RS), showing a different population in Belém, while the others did not show a clearly defined structure. The population dynamics were analyzed for fishes of Arraial do Cabo, São Paulo and Porto Belo, collected monthly of January/2002 to July/2003. The cutlassfish spawning is parceled with reproductive period from the summer to the beginning of the winter. Ripe females migrate offshore to mate with ripe males that stay there, returning to the coast just after spawning. The length of first sexual maturity varied from 647 to 670mm (Lt) for females, and 526 to 650mm for males. The estimates of growth parameters were: for females Loo from 1740 to 2010mm; k from 0,12 to 0,15/year and t0 from -1,642 to -2,517 years, and for males Loo from 1373 to 1580mm; k from 0,171 0.255/year and t0 from -1,662 to -1,866 years. The longevity was about 14 years. The natural mortality rate varied from 0,20 to 0,29/year. The relative yield per recruit model showed that fishing mortality rates of the cutlassfish are close or just exceeding the limits of the maximum sustainable yield.

Os aspectos da pesca do espada, Trichiurus lepturus (Linnaeus, 1758) (Trichiuridae), foram descritos e analisados para as artes de pesca artesanal de linha-de-mão em Arraial do Cabo (RJ) e cerco flutuante em Porto Belo (SC), e da pesca comercial de arrasto de fundo com parelhas na costa de São Paulo. Verificaram-se tendências crescentes na produção da espécie, principalmente na pesca artesanal. Foram utilizados marcadores moleculares tipo RAPD para analisar a estrutura genético-populacional da espécie com exemplares de Belém (PA), Natal (RN), Arraial do Cabo (RJ), Guarujá (SP), Porto Belo (SC) e Rio Grande (RS), evidenciando-se uma população distinta em Belém, enquanto as demais não apresentaram estruturação definida. A dinâmica de populações foi analisada para exemplares de Arraial do Cabo, São Paulo e Porto Belo, coletados mensalmente de janeiro/2002 a julho/2003. A desova da espécie é parcelada com período reprodutivo ocorrendo do verão ao início do inverno. As fêmeas maduras migram para a plataforma encontrando-se com os machos maduros que ali permanecem, retornando à costa após a desova. O comprimento médio de primeira maturação sexual variou de 647 a 670mm (Lt) para fêmeas, e de 526 a 650mm para machos. As estimativas dos parâmetros de crescimento foram as seguintes: para fêmeas Loo de 1740 a 2010mm; k de 0,12 a 0,15/ano e t0 de -1,642 a -2,517 anos; para machos Loo de 1373 a 1580mm; k de 0,17 a 0.25/ano e t0 de -1,662 a -1,866 anos. A longevidade foi cerca de 14 anos. As taxas de mortalidade natural variaram de 0,20 a 0,29/ano. O modelo de rendimento relativo por recruta indicou que as taxas de mortalidade por pesca do espada estão próximas ou já ultrapassam os limites do rendimento máximo sustentável. / The fishery aspects of the cutlassfish, Trichiurus lepturus (Linnaeus, 1758) (Trichiuridae), were analyzed for the artisanal fishery of line and hook of Arraial do Cabo (RJ) and floating encirclement of Porto Belo (SC), and of the commercial paired bottom trawlers in the coast of São Paulo. Tendencies in increasing yields were detected, mainly in the artisanal fishery. RAPD markers techniques were employed in order to analyze the genetic-population structure of the cutlassfish from Belém (PA), Natal (RN), Arraial do Cabo (RJ), Guarujá (SP), Porto Belo (SC) and Rio Grande (RS), showing a different population in Belém, while the others did not show a clearly defined structure. The population dynamics were analyzed for fishes of Arraial do Cabo, São Paulo and Porto Belo, collected monthly of January/2002 to July/2003. The cutlassfish spawning is parceled with reproductive period from the summer to the beginning of the winter. Ripe females migrate offshore to mate with ripe males that stay there, returning to the coast just after spawning. The length of first sexual maturity varied from 647 to 670mm (Lt) for females, and 526 to 650mm for males. The estimates of growth parameters were: for females Loo from 1740 to 2010mm; k from 0,12 to 0,15/year and t0 from -1,642 to -2,517 years, and for males Loo from 1373 to 1580mm; k from 0,171 0.255/year and t0 from -1,662 to -1,866 years. The longevity was about 14 years. The natural mortality rate varied from 0,20 to 0,29/year. The relative yield per recruit model showed that fishing mortality rates of the cutlassfish are close or just exceeding the limits of the maximum sustainable yield.

Abstract Many plant species inhabiting the seashore meadows of the Bothnian Bay, especially early successional ones, have become threatened. Isostatic land uplift creates virgin land for early successional species to colonise. However, at the same time it gradually elevates the habitat and eventually makes the habitat unsuitable for them. Disturbances of the waterfront may slow down succession and create new empty sites. In order to persist on the shores, pioneer species have to be able to colonise new sites by seeds, vegetative propagules or growth. In this thesis I studied the status of an endangered early successional grass species, A. fulva var. pendulina, at the Liminka Bay. According to a matrix population model based on eight years of observations (1992–1999), the population seemed not to be in immediate danger of extinction. However, simulations based on four-year field observations (2000–2003) indicated that if the current trend continues, the species will decrease considerably in area in the next 30 years. In the field studies no seedlings or viable seeds of A. fulva were found. In spite of this, high genotypic diversity was found in the A. fulva population, suggesting that sexual reproduction has taken place at some time during the history of the population. Analysis of the population structure revealed a low level of genotypic differentiation between subpopulations and significant sub-structuring within subpopulations. The overall pattern of genetic variation suggests that the population has characters of both stepping-stone and metapopulation models. The results of the study on the ability of a seashore plant Potentilla anserina ssp. egedii to change its allocation of resources to sexual and vegetative reproduction according to competitive stress implied that the species can modify the allocation of resources to different life-history traits. For a plant living in disturbance-prone environment, it may be beneficial to be able to rapidly track the competition-free space formed by disturbances by changing its reproductive pattern. Management studies on three endangered seashore plant species showed that deterioration of suitable habitats of A. fulva and Primula nutans var. jokelae could be slowed down by management, and the vegetative and/or sexual reproduction of these species was enhanced. However, in the case of Puccinellia phryganodes, no positive response to management was observed.

Helicobacter pylori est associée à des pathologies gastro-duodénales sévères mais est également un marqueur bactérien de migrations humaines. Nous avons montré que des populations génétiques distinctes de H. pylori ont accompagné au moins quatre migrations en Asie du sud-est et en Océanie : i) une expansion des ancêtres des austronésiens il y a 5000 ans à partir de Taiwan en Océanie, ii) une migration d’Inde en Asie du sud-est depuis 2000 ans,iii) une migration des ancêtres des locuteurs des langues austro-asiatiques au Vietnam et auCambodge il y a 4000 ans, i) une migration des ancêtres des Thaïs du sud de la Chine vers l’actuelle Thaïlande au début du second millénaire. Ces données confirment la résolution plus élevée de la diversité génétique de H. pylori pour retracer les anciennes migrations humaines par comparaison aux marqueurs génétiques humains traditionnels. Nous avons ensuite investigué les facteurs de virulence de souches isolées de patients présentant des symptômes gastriques au Sénégal et au Cambodge. Au Sénégal, une association significative a été observée entre le cancer gastrique et le gène cagA, deux motifs EPIYA-C et l’allèle vacA s1. De multiples segments EPIYA-C étaient observés moins fréquemment que dans les autres régions du monde, contribuant probablement à la faible incidence du cancer gastrique. Au Cambodge, une introgression fréquente d’allèles cagA et vacA européens dans des souches d’Asie de l’est a été observée. CagA et VacA ayant des effets antagonistes, cette expansion pourrait entraîner la rupture de l’équilibre entre les effets biologiques de ces deux protéines et être responsable de conséquences graves sur l’évolution de la maladie. / Helicobacter pylori is associated with severe gastroduodenal disorders but is also a bacterial genetic marker of human migrations. First, we provide evidence that distinct H. pylori genetic populations accompanied at least four ancient human migrations into Oceania and Southeast Asia: i) an expansion of Austronesian speaking people about 5000 years ago from Taiwan into Oceania, ii) a migration from India into Southeast Asia within the last 2000 years, iii) a migration of Austro-Asiatic speaking people into Vietnam and Cambodia about 4000 years ago, and iv) a migration of the ancestors of the Thai people from Southern China into Thailand during the early second millennium AD. These findings demonstrate that H. pylori genetic diversity has more discriminatory power than traditional human genetic markers for tracing old human migrations. Second, we investigated virulence factors of H. pylori strains isolated from patients with gastric symptoms in Senegal and Cambodia. In Senegal, a significant association was observed between gastric cancer and the cagA gene, two EPIYA-C segments, and the s1 vacA allele in Senegal. Multiple EPIYA-C segments were less frequent than reported in other countries, possibly contributing to the low incidence of gastric cancer. In Cambodia, the frequent introgression of European vacA and cagA alleles into East Asian H. pylori strains was observed. As VacA and CagA have opposing effects, this expansion may disrupt the balancing activities on epithelial cells which might result in severe consequences for individual disease outcome.

Orientador: Fernando Fernandes Mendonça / Resumo: A atividade pesqueira desempenha um importante papel ambiental e socioeconômico, pois é fonte de renda e alimento para milhões de pessoas no mundo. Entretanto, falhas em sua gestão e lacunas nos dados biológicos para muitas espécies, tem resultado na sobreexplotação de seus estoques, o que pode impactar diversos ecossistemas marinhos. Neste contexto, os peixes-de-bico, grupo formado pelas famílias Xiphiidae e Istiophoridae, são considerados valiosos recursos pesqueiros, porém ainda não há consenso sobre o número e a validade das espécies da família Istiophoridae e também há incertezas sobre a avaliação atual de seus estoques. Sendo assim, o objetivo deste estudo é o de delimitar as espécies da família Istiophoridae e os estoques genéticos do agulhão-vela Istiophorus platypterus no Oceano Atlântico utilizando marcadores moleculares mitocondriais. Entre os resultados dos testes de delimitação de espécies, o número variou entre 6 e 12 táxons possíveis, dependendo do teste aplicado. Em relação a delimitação dos estoques genéticos de I. platypterus no Atlântico, assumindo-se apenas uma espécie no gênero Istiophorus, nossos resultados apontam a existência de alta diversidade genética, componde um único estoque genético no Atlântico (ΦST=0,01121, p=0,02438), apresentando um alto fluxo gênico. Porém, pela análise da rede de haplótipos e da inferência bayesiana observa-se a existência de diferentes linhagens mitocondriais simpátricas, que divergiram durante o Mioceno Superior e foram ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Fishing activity plays an important environmental and socio-economic role, as it is a source of income and food for millions of people worldwide. Although, shortcomings in management and gaps in biological data for many species resulted in the overexploitation of their stocks, which may impact several marine ecosystems. In this context, billfishes, a group compounded by the Xiphiidae and Istiophoridae families, are considered valuable fish resources, but there is still no consensus on the number and validity of the species of Istiophoridae family and there are also uncertainties about the current fisheries stocks assessments. Thus, the main objectives of this study are to delimit the species of the Istiophoridae family and the genetic stocks of the sailfish, Istiophorus platypterus, in the Atlantic Ocean using mitochondrial molecular markers. Among the species delimitation tests results, the number ranged from 6 to 12 possible taxa depending on the test applied. In order to determine the genetic stock of I. platypterus in the Atlantic Ocean, assuming only one species in the genus Istiophorus, our results point to the existence of high genetic diversity, comprising a single genetic stock in the Atlantic (ΦST = 0.01121, p = 0.02438), presenting a high gene flow. However, the analysis of the network of haplotypes and Bayesian inference shows the existence of different sympatric mitochondrial lines, which diverged during the Upper Miocene and were re-approximated, interrupting th... (Complete abstract click electronic access below) / Doutor