Browsing by Issue Date, starting with "2013-04"
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- Effects of coastal orientation and depth on the distribution of subtidal benthic assemblagesPublication . Martins, Gustavo M.; Patarra, Rita F.; Álvaro, Nuno V.; Prestes, Afonso L.; Neto, Ana I.A better understanding of biological systems can only be gained if we understand what processes are important and how they operate to determine the distribution of organisms. Coastal orientation and depth can influence environmental conditions, including the degree of water motion and availability of light, which in turn may influence the horizontal and vertical patterns of organism distribution. Here, we used a mixed-model design to examine the effects of coastal orientation and depth on the structure of benthic assemblages by comparing the abundance and distribution of macroalgae and invertebrates in shallow and deep waters on the opposing coasts of Sa˜o Miguel. Generally, coastal orientation had little influence on the distribution of most taxa. In contrast, significant differences were generally associated with depth, although patterns were spatially variable at the scale of locations. This study suggests that depth, and processes operating at the scale of location, but not at the scale of the coast, have an important influence on these assemblages, and that failure to recognise such a scale of variability may hamper our ability to better understand the processes that structure these communities.
- Climatology and Atmospheric Chemistry of Non-Methane Hydrocarbon Emissions over the North Atlantic.Publication . Muñoz, Mauricio; Helmig, Detlev; Hueber, Jacques; Mazzoleni, Claudio; Mazzoleni, Lynn R.; Owen, Robert; Val Martin, Maria; Fialho, Paulo; Plass-Duelmer, ChristianNon-methane hydrocarbons (NMHC) covering the C2 to C7 volatility range have been monitored at the Pico Mountain Observatory, Pico Island, Azores, Portugal, since 2004. The Observatory is located at 2225 m a.s.l. in the caldera of the Pico Mountain volcano, and during most times receives lower free tropospheric air that has been transported across the North Atlantic. The 7-year NMHC record has been analyzed for seasonal behavior of photochemical processing, atmospheric transport time, and source region using ratios of NMHC species as indicators of photochemical aging and HYSPLIT model outputs. Transport conditions resulting in elevated and low NMHC conditions were specifically studied to investigate seasonal pollution transport in the North Atlantic region.
- Chemical study and biological activity evaluation of two Azorean Macroalgae: Ulva rigida and Gelidium microdonPublication . Silva, Madalena; Vieira, Luís M.; Almeida, Ana Paula; Silva, Artur M. S.; Seca, Ana M. L.; Barreto, Maria do Carmo; Neto, Ana I.; Pedro, Madalena; Pinto, Eugénia; Kijjoa, AnakeThe green macroalga Ulva rigida C. Agardh (Chlorophyta) and the red macroalga Gelidium microdon Kützing (Rhodophyta), collected from the Azorean archipelago, were investigated for their secondary metabolites and their in vitro growth inhibitory effect on three human tumor cell lines: MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and A375-C5 (melanoma), as well as for their antifungal and antibacterial activities. The methanol extract of U. rigida furnished isofucosterol (1), 7(E)-3β-hydroxy-5α,6α-epoxymegastigmane (2) and (+)-dehydrovomifoliol (3) while the methanol extract of G. microdon yielded cholesterol (4) and lumichrome (5). The crude extracts of both macroalgae were found to be moderately active against the three cell lines whereas compound 1 showed a weak effect and compound 2 was inactive. The crude extracts of the two macroalgae were found to be moderately active against some fungi and bacteria while compounds 1 and 2 were inactive against all microorganisms tested.
- Delfim Santos e a verdade como desafio e limite do conhecimentoPublication . Luz, José Luís Brandão daO tema da verdade atravessa a obra filosófica de Delfim Santos, fazendo parte integrante da reflexão sobre o conhecimento que o autor compreende na confluência do esforço de clarificação das noções de verdade e de realidade. Propomos abordar esta dimensão capital do seu pensamento, primeiramente, no quadro da crítica a que submeteu os propósitos do programa do Círculo de Viena da construção duma gramática do discurso científico susceptível de assegurar a sua expressão em condições de verdade, de seguida, na valorização da dimensão metafísica da filosofia e da consequente exploração da noção de realidade, por fim, na análise da noção de verdade, que se compreende em estreita ligação com as «regiões da realidade», e procurando clarificar o sentido da relatividade que lhe parece estar associado.
- Integration of non-indigenous species within the interspecific abundance-occupancy relationshipPublication . Rigal, François; Whittaker, Robert J.; Triantis, Kostas A.; Borges, Paulo A. V.There is a broad consensus that habitat disturbance and introduction of non-indigenous species may dramatically modify community structure, particularly in insular ecosystems. However, it is less clear whether emergent macroecological patterns are similarly affected. The positive interspecific abundance–occupancy relationship (IAOR) is one of the most pervasive macroecological patterns, yet has rarely been analyzed for oceanic island assemblages. We use an extensive dataset for arthropods from six islands within the Azorean archipelago to test: (1) whether indigenous and non-indigenous species are distributed differently within the IAOR; and (2) to the extent that they are, can differences can be attributed to two indices of disturbance. We implemented modeling averaged methods using five of the most common IAOR models to derive an averaged IAOR fit for each island. After testing if species colonization status (indigenous versus non-indigenous) may explain the residuals of the IAOR, we identified true negative and positive outliers and tested the effect of colonization status on the likelihood of a species being a positive or negative outlier. We found that the indigenous and non-indigenous species are randomly distributed on both sides of the overall IAOR. Only for Flores Island, were non-indigenous species more aggregated than indigenous species. We were unable to detect a meaningful relationship between deviation from the IAOR and disturbance, despite the undoubted impact of both severe habitat loss and non-indigenous species on these oceanic islands. Our results show that the non-indigenous species have been integrated alongside indigenous species in the contemporary Azorean arthropod communities such that they are mostly undetectable by the study of the IAOR.
- Coeficientes de Comparação de Partições em Análise Classificatória: Abordagem Clássica vs uma Abordagem ProbabilísticaPublication . Silva, Osvaldo; Bacelar-Nicolau, Helena; Nicolau, Fernando C.; Sousa, ÁureaExistem diversos índices para a comparação de partições, o que dificulta a tomada de decisão, dado que diferentes índices põem geralmente em evidência diferentes peculiaridades das partições a comparar. Com o intuito de auxiliar nessa avaliação, é apresentada e exemplificada uma abordagem para a comparação de partições, com base na semelhança VL (Validade da Ligação), a qual tem, entre outras, a vantagem de uniformizar a escala de medida. A comparação dos resultados obtidos com a aplicação de índices de comparação de partições, clássicos e probabilísticos do tipo VL, é feita sobre um conjunto de dados reais.
- Measurement of Aerosols and Trace Gases in the Free Troposphere at the Pico Mountain Observatory in the Azores.Publication . Kramer, Louisa; Mazzoleni, Claudio; Mazzoleni, Lynn R.; Fialho, Paulo; Helmig, Detlev; Olsen, Seth C.; Owen, R. Chris; Dziobak, Michael P.; Hueber, Jacques; Dzepina, Katja; Kumar, SumitHere, we present an overview of gas and aerosol data measured at the Pico Mountain Station. The primary objective of these measurements are to enhance our knowledge of anthropogenic and biomass burning emissions from North America and their relative impact on atmospheric composition and radiative forcing in the free troposphere of the North Atlantic.
- How do different dispersal modes shape the species-area relationship? Evidence for between-group coherence in the Macaronesian floraPublication . Aranda, Silvia C.; Gabriel, Rosalina; Borges, Paulo A. V.; Santos, Ana M. C.; Hortal, Joaquín; Baselga, Andrés; Lobo, Jorge M.AIM: We explore the island species–area relationships (ISARs) of several plant groups differing in dispersal ability. We examine whether: (i) the ISAR slope is higher for less dispersive groups (diminishing from not-wind-dispersed seed plants to wind-dispersed seed plants, pteridophytes and bryophytes); and (ii) the regional richness is higher than that predicted by the ISAR of its constituent islands for groups with lower dispersal ability. Additionally, we relate both patterns to the compositional dissimilarity (beta diversity) between islands. LOCATION: The Macaronesian archipelagos of the Azores, Madeira and Canary Islands. METHODS: ISARs were estimated using the conventional power model. Differences in slopes among taxa were analysed through ANCOVA tests. We assessed the deviation of the total richness of the Macaronesian flora from that predicted by the ISAR and calculated several measures of beta diversity (turnover, nestedness-resultant dissimilarity and nestedness). Analyses were repeated after excluding the two Canarian islands of Lanzarote and Fuerteventura, which have unique climatic and geological conditions in the region. RESULTS: All ISAR models were significant except for pteridophytes (for which it was significant when excluding Lanzarote and Fuerteventura). ISAR slopes did not differ among taxa. Regional richness followed ISAR predictions for bryophytes and pteridophytes when Lanzarote and Fuerteventura were excluded, while the total number of Macaronesian seed plants (particularly not-wind-dispersed species) always fell above the ISAR. Turnover was higher in seed plants than in bryophytes and pteridophytes, and the opposite occurred with nestedness. MAIN CONCLUSIONS: Differences in dispersal ability influence the compositional dissimilarity between these islands, but not the rate of species increase with area. This may be because ISAR slopes are mostly determined by within-island processes of species accumulation, while differences in dispersal generate different between island patterns. The lack of relationship between the ISAR slope and species replacement or nestedness prevents its use as a proxy for beta diversity.
- Discursos sobre homossexualidade numa comunidade educativa : perspetivas de professoresPublication . Rodrigues, Catarina Alexandra Freitas; Rego, Isabel Estrela; Santos, Luís Filipe OliveiraO presente estudo, de caracter qualitativo e exploratório pretende aceder à compreensão dos discursos e da ação verbalizada de professores em relação à homossexualidade numa perspetiva construcionista. Mais concretamente, procurou-se captar as perspetivas destes (perspetiva pessoal) sobre a homossexualidade em geral e a homossexualidade na escola, bem como as perspetivas que consideram que os outros têm (perspetiva social), tanto na escola como fora desta. Selecionaram-se para participar no estudo 16 professores a lecionar em escolas públicas da ilha de São Miguel, tendo em consideração os critérios: sexo, idade, departamento que integram na escola onde lecionam, anos de serviço e experiência de ensino com alunos adolescentes, em diferentes instituições. A recolha de dados foi realizada através de entrevistas em profundidade, semiestruturadas. Como procedimento de tratamento de dados realizou-se a análise de conteúdo (Bardin, 1995 & Vala, 1986), seguindo o "Modelo Interativo de Análise de Dados" proposto por Miles & Huberman (1984 cit. in Lessard-Hébert et al, 1990). De acordo com os dados emergentes verificou-se a existência de constrangimentos, tanto na vida pessoal como na prática profissional face à homossexualidade. Embora a maioria dos participantes no estudo assuma um discurso socialmente polido com conceitos como respeito e naturalidade, permanece a desigualdade, o preconceito, a discriminação e, como consequência, a opção pela invisibilidade. Na escola, é a partir da ideia de heterossexualidade que os conteúdos são elaborados, e que os discursos são produzidos. Ainda escasseiam informações no que concerne à sexualidade e, em particular, à homossexualidade e os professores admitem a falta de preparação para a abordagem do tema. Também, a referência à homossexualidade como forma de insulto entre os alunos parece ser uma prática tão comum que, na generalidade, não é considerada como agressão. Os resultados sugerem ainda que a formação específica na temática homossexualidade parece constituir não só um meio eficaz de desconstrução de modelos enraizados em padrões culturais, como aumentar a consciência para práticas discursivas que têm em conta a diversidade.
- QuadratumPublication . Melo, Helena Sousa; Vinagre, SandraEste resumo apresenta um novo jogo tridimensional que pode ser aplicado desde o 1.º ciclo do Ensino básico até outros níveis de ensino aplicando alguma variantes.