616 research outputs found

    Arthropod co-occurrence networks indicate environmental differences between islands and signal introduced species in Azorean native forest remnants

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    Island biotas are in imminent threat from anthropogenic impacts. Of these impacts, the negative effects of exotic species on the taxonomic and functional diversity of the local fauna are of major concern. Exotics may also have a detrimental effect on interspecific interactions which, in turn, can destabilize ecological networks. Species co-occurrence networks can detect species-to-species associations and are used to predict ecological interaction networks and utilized as tools to assess environmental impacts on community structure. Here, we aim to investigate whether or not topological differences of the arthropod co-occurrence networks among native forest fragments from seven Azorean islands can reveal the influence of the abiotic environment and exotic species on these networks. Co-occurrence networks were sensitive to environmental and community dissimilarities, showing a clear separation between islands and pinpointed differences between indigenous and exotic networks. Most exotics were little connected and exotic networks had a large proportion of unconnected species. The resulting decreased connectance and the increased modularity with the increase of the proportions of exotics in the networks suggest that most exotics have too low prevalence to show associations with other species, and only a few dominants drive co-occurrences. The proportion of negative links, as indicators of competition, did not increase with the increase of exotics in the habitats, suggesting that exotics provided new functional roles when they colonized native forest remnants. However, when the theoretical networks consisting of only indigenous species were investigated, connectance decreased and closeness increased with the increase of exotics, suggesting processes of network degradation. Since our study provides ample evidence for the usefulness of co-occurrence network analysis in studying island ecosystems, we recommend the use of this tool for ecosystem assessments, early warning systems and decision-making in island biodiversity conservation.info:eu-repo/semantics/publishedVersio

    Assessing the efficiency of protected areas to represent biodiversity : a small island case study

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    Protected areas (PAs) have been selected using either subjective or objective criteria applied to an extremely limited subset of biodiversity. Improved availability of species distribution data, better statistical tools to predict species distributions and algorithms to optimize spatial conservation planning allow many impediments to be overcome, particularly on small islands. This study analyses whether 219 species are adequately protected by PAs on Pico Island (theAzores, Portugal), and if they are as efficient as possible, maximizing species protection while minimizing costs. We performed distribution modelling of species’ potential distributions, proposed individual conservation targets (considering the context of each species in the archipelago and their current conservation status) to determine the efficiency of current PAs in meeting such targets and identify alternative or complementary areas relevant for conservation. Results showed that current PAs do not cover all taxa, leaving out important areas for conservation. We demonstrate that by using optimization algorithms it is possible to include most species groups in spatial conservation planning in the Azores with the current resources. With increasing availability of data and methods, this approach could be readily extended to other islands and regions with high endemism levels.info:eu-repo/semantics/publishedVersio

    Difference in Virulence of Mycobacterium avium Isolates Sharing Indistinguishable DNA Fingerprint Determined in Murine Model of Lung Infection

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    Background: Opportunistic Mycobacterium avium typically causes disease in immunocompromised patients and in some groups of apparently healthy individuals. the high virulence of some bacterial lineages increases the disease risk. High-resolution molecular genotyping studies of M. avium clinical isolates demonstrated that some genotype patterns were more prevalent than others, suggesting that close genetic relatedness of these successful isolates sharing a similar genotype could determine similar biological properties associated with high virulence.Methods and Findings: in this study, we aimed to compare the virulence and pathogenic properties of two epidemiologically unrelated M. avium isolates sharing an indistinguishable DNA fingerprint in a well-characterized model of pulmonary infection in mice, resistant or susceptible to mycobacteria. the mice, C57BL/6 wild-type or IFN-gamma gene disrupted (GKO), respectively, were intratracheally infected with two isolates, H27 (human blood isolate) and P104 (pig lymph node isolate), and the lungs were examined for bacterial loads, histopathology and cytokine gene expression. the obtained data demonstrated significant differences in the virulence properties of these strains. Although the H27 strain grew significantly faster than P104 in the early stage of infection, this bacterium induced protective immunity that started to reduce bacterial numbers in the wild-type mice, whereas the P104 strain established a chronic infection. in the GKO mice, both strains were capable of causing a chronic infection, associated with higher bacterial burdens and severe lung pathology, in a similar manner.Conclusions/Significance: the results demonstrated that the studied isolates differed in the pathogenic properties although were indistinguishable by actually widely used genotyping techniques demonstrating that the genotype similarity does not predict similarity in virulence of M. avium isolates.Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Estadual Norte Fluminense, Lab Biol Recognit, Rio de Janeiro, BrazilUniv Estadual Norte Fluminense, Lab Anim Morphol & Pathol, Rio de Janeiro, BrazilInst Butantan, Lab Immunochem, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Immunol & Parasitol, São Paulo, BrazilFAPERJ: E-26/111.6111CNPq: 410555Web of Scienc

    Zymomonas mobilis: a promising microorganism for prebiotic production

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    Zymomonas mobilis (ZM) is an ethanologenic bacterium with outstanding characteristics which makes it an interesting chassis for the biotechnological production of prebiotics. Fructooligosaccharides (FOS) are promising prebiotics in the increasing market of functional food. In this work, a Box-Behnken design approach was used to optimize the medium composition and maximize the FOS content. Under optimal conditions, 45.3 g/L of FOS were obtained. Sucrose was the most significant variable; thus, its concentration was further increased to 350 g/L leading to a 1.13-fold enhance in FOS titer. Afterwards, a scale-up to bioreactor was performed resulting in a high yield, content and productivity of FOS (58 %, 156.5 g/L 4.8 g/L h). Furthermore, 45 g/L of sorbitol and 8 g/L of levan were also produced. After purification of the FOS mixture through an activated charcoal column, an in vitro model using human fecal inoculum was used to assess its prebiotic potential. The results suggest that the produced prebiotic mixture has potential to be used to improve the human health. The present work describes for the first time the production of a prebiotic mixture with ZM ZM4 in an in vivo single-step approach that has potential to be commercialized as functional food ingredient.João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (UMINHO/BPD/4/2019, SFRH/BD/138325/2018, SFRH/BD/132324/2017, and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and the project FoSynBio (POCI-01-0145-FEDER-029549).info:eu-repo/semantics/publishedVersio

    Adolescence, sexual life and reproductive planning of adolescents of Serra Pelada, Pará

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    The life conditions in which an adolescent develops determine his choices and influence his sexual life. The present study aimed to characterize the daily activities and sexual life of 108 adolescents aged between 11 and 15 years, living in Serra Pelada, a municipality of Curionópolis, state of Pará, through a quantitative and qualitative data analysis, distinguishing them according to gender. Results showed the strong presence of gender relations in some cases. Some relation was found between religion and sexual life only in the female sex: 58.5% of them followed some religion and 66.7% had not initiated sexual life at the age of 12 or below. When the adolescents were asked whether they had sexual intercourse with their boyfriends or girlfriends, 93.6% of the girls answered they did not, while 59.6% of the boys answered the same, showing that the girls avoid more the sexual intercourse. The great majority of the girls stated they used a contraceptive method in the first intercourse, while more than 50% of the boys said the opposite. This difference reveals that the responsibility for contraception is deemed as belonging to the female sex. Approximately 70% of the girls state they intend to marry the person with whom they are currently having sexual intercourse, while 60% of the boys say the opposite, which shows that the girls are more afraid to have children early, and more open to commitments.As condições de vida em que um adolescente se desenvolve determinam suas escolhas e influenciam sua vida sexual. O presente estudo visou caracterizar o cotidiano e vida sexual de 108 adolescentes entre 11 e 15 anos de idade, residentes em Serra Pelada, município de Curionópolis, PA, através de análise quantitativa e qualitativa de dados, diferenciando-os quanto ao gênero. Os resultados mostraram a forte presença das relações de gênero em alguns casos. Foi encontrada alguma relação entre religião e vida sexual somente no sexo feminino, em que se observa que 58,5% delas eram adeptas a alguma religião e 66,7 % não haviam iniciado a vida sexual aos 12 anos ou menos. Quando questionados se mantinham, ou não, relações sexuais enquanto namoravam, 93,6% das meninas afirmaram que não, enquanto 59,6% dos meninos disseram o mesmo, mostrando que as meninas evitam mais a relação sexual. A grande maioria das meninas afirmou ter feito uso de método para evitar filho na primeira relação, enquanto mais de 50% dos meninos afirmaram o contrário. Essa diferença reflete que a responsabilidade da contracepção é julgada como pertencente ao sexo feminino. Cerca de 70% das meninas afirmam ter a intenção de se casar com a pessoa com quem tem relação sexual atualmente, enquanto 60% dos meninos afirmam o contrário, o que mostra que as meninas se mostram mais receosas quanto a ter filho cedo, em relação aos garotos, e mostram-se mais abertas ao compromisso

    Spatial Factors Play a Major Role as Determinants of Endemic Ground Beetle Beta Diversity of Madeira Island Laurisilva

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    The development in recent years of new beta diversity analytical approaches highlighted valuable information on the different processes structuring ecological communities. A crucial development for the understanding of beta diversity patterns was also its differentiation in two components: species turnover and richness differences. In this study, we evaluate beta diversity patterns of ground beetles from 26 sites in Madeira Island distributed throughout Laurisilva – a relict forest restricted to the Macaronesian archipelagos. We assess how the two components of ground beetle beta diversity (βrepl – species turnover and βrich - species richness differences) relate with differences in climate, geography, landscape composition matrix, woody plant species richness and soil characteristics and the relative importance of the effects of these variables at different spatial scales. We sampled 1025 specimens from 31 species, most of which are endemic to Madeira Island. A spatially explicit analysis was used to evaluate the contribution of pure environmental, pure spatial and environmental spatially structured effects on variation in ground beetle species richness and composition. Variation partitioning showed that 31.9% of species turnover (βrepl) and 40.7% of species richness variation (βrich) could be explained by the environmental and spatial variables. However, different environmental variables controlled the two types of beta diversity: βrepl was influenced by climate, disturbance and soil organic matter content whilst βrich was controlled by altitude and slope. Furthermore, spatial variables, represented through Moran’s eigenvector maps, played a significant role in explaining both βrepl and βrich, suggesting that both dispersal ability and Madeira Island complex orography are crucial for the understanding of beta diversity patterns in this group of beetles.Peer reviewe

    Recuperação de área degradada com sistema agroflorestal no Vale do Rio Doce, Minas Gerais.

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    O Vale do Rio Doce, MG, apresenta um histórico de ocupação e uso do solo que favorece a degradação ambiental, em que predominam pastagens sob o uso constante de queimadas. Os sistemas agroflorestais têm se mostrado eficientes na recuperação de áreas degradadas. Neste estudo foram avaliados os efeitos de um sistema agroflorestal na recuperação do solo em área degradada por pastagem na comunidade de Ilha Funda,Município de Periquito, Minas Gerais. A implantação do sistema se deu em 1994 e está sendo conduzido segundo os princípios agroecológicos, potencializando a regeneração natural e a sucessão de espécies. Em 1998, foram coletadas amostras de solo na área em recuperação e em duas áreas adjacentes: uma área degradada, que se encontrava em condições semelhantes às da área em recuperação no início do processo, e outra ocupada por pastagem. Foram determinados atributos químicos do solo e realizada a caracterização da matéria orgânica. O solo da área em recuperação com sistema agroflorestal mostrou-se em melhores condições do que o solo sob pastagem e o da área degradada, apresentando maior dinâmica do carbono orgânico e maior disponibilidade de nutrientes. Embora o teor de carbono orgânico total apresentado pelo solo sob pastagem tenha sido maior que nas demais condições avaliadas, o solo do sistema agroflorestal já está se igualando ao da pastagem no acúmulo das formas mais estáveis de carbono e apresentando maior dinâmica das frações orgânicas menos estáveis. Este estudo comprovou a eficiência dos sistemas agroflorestais, conduzidos segundo os princípios agroecológicos, na recuperação de áreas degradadas

    Avaliar a eficiência das áreas protegidas para representar a biodiversidade: o caso de estudo de uma pequena ilha

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    A secção Biologia é coordenada pelo Professor Universitário Armindo Rodrigues.[…]. Nos Açores podem ser encontradas inúmeras espécies endémicas que tornam este arquipélago importante, do ponto de vista da conservação dos valores naturais. A rede de APs nos Açores está organizada em Parques Naturais de Ilha, no Parque Marinho dos Açores e em APs de importância local. O Parque Natural de Ilha (PNI) engloba diferentes categorias de áreas terrestres e marinhas, que possuem diferentes objectivos de conservação. No sentido de avaliar a adequação dos actuais limites das APs do ponto de vista da conservação das espécies, tendo a Ilha do Pico como caso de estudo, foram analisadas 219 espécies nativas dos Açores (briófitos, plantas vasculares, moluscos, artrópodes e vertebrados), na sua maioria endémicas. […].info:eu-repo/semantics/publishedVersio
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