Untangling associations between chironomid taxa in Neotropical streams using local and landscape filters

1. Analyses of species association have major implications for selecting indicators for freshwater biomonitoring and conservation, because they allow for the elimination of redundant information and focus on taxa that can be easily handled and identified. These analyses are particularly relevant in the debate about using speciose groups (such as the Chironomidae) as indicators in the tropics, because they require difficult and time-consuming analysis, and their responses to environmental gradients, including anthropogenic stressors, are poorly known. 2. Our objective was to show whether chironomid assemblages in Neotropical streams include clear associations of taxa and, if so, how well these associations could be explained by a set of models containing information from different spatial scales. For this, we formulated a priori models that allowed for the influence of local, landscape and spatial factors on chironomid taxon associations (CTA). These models represented biological hypotheses capable of explaining associations between chironomid taxa. For instance, CTA could be best explained by local variables (e.g. pH, conductivity and water temperature) or by processes acting at wider landscape scales (e.g. percentage of forest cover). 3. Biological data were taken from 61 streams in Southeastern Brazil, 47 of which were in well-preserved regions, and 14 of which drained areas severely affected by anthropogenic activities. We adopted a model selection procedure using Akaike`s information criterion to determine the most parsimonious models for explaining CTA. 4. Applying Kendall`s coefficient of concordance, seven genera (Tanytarsus/Caladomyia, Ablabesmyia, Parametriocnemus, Pentaneura, Nanocladius, Polypedilum and Rheotanytarsus) were identified as associated taxa. The best-supported model explained 42.6% of the total variance in the abundance of associated taxa. This model combined local and landscape environmental filters and spatial variables (which were derived from eigenfunction analysis). However, the model with local filters and spatial variables also had a good chance of being selected as the best model. 5. Standardised partial regression coefficients of local and landscape filters, including spatial variables, derived from model averaging allowed an estimation of which variables were best correlated with the abundance of associated taxa. In general, the abundance of the associated genera tended to be lower in streams characterised by a high percentage of forest cover (landscape scale), lower proportion of muddy substrata and high values of pH and conductivity (local scale). 6. Overall, our main result adds to the increasing number of studies that have indicated the importance of local and landscape variables, as well as the spatial relationships among sampling sites, for explaining aquatic insect community patterns in streams. Furthermore, our findings open new possibilities for the elimination of redundant data in the assessment of anthropogenic impacts on tropical streams.

Ephemeroptera, Plecoptera and Trichoptera assemblages from riffles in mountain streams of Central Brazil: environmental factors influencing the distribution and abundance of immatures

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reflexões sobre a anticoncepção na adolescência no Brasil

Faz-se uma reflexão sobre a contracepção e suas conseqüências na adolescência, baseada em trabalhos nacionais e internacionais alertam para a precocidade do início da atividade sexual, a qual expõe os adolescentes aos riscos da gravidez e das doenças sexualmente transmissíveis e AIDS. Verifica-se que a maioria dos adolescentes recebe informações sobre contracepção, sendo a pílula e o preservativo os mais conhecidos e utilizados. Porém, registram-se elevada inadequação na utilização dos métodos contraceptivos, além da falta de serviços assistências, onde possam buscar orientações e atendimento. Tal realidade alerta para a necessidade de maior envolvimento de profissionais da saúde, da educação, família e comunidade, garantindo qualidade de vida aos adolescentes.

Abortamento na adolescência: um estudo epidemiológico

O presente trabalho foi desenvolvido no Hospital Maternidade Santa Izabel da cidade de Bauru, São Paulo, Brasil, e teve como objetivo investigar o abortamento na adolescência e compará-lo com o das mulheres adultas. Os indicadores buscaram traçar o perfil epidemiológico das mulheres internadas, por meio de dados coletados em prontuários, entre aquelas com diagnóstico de aborto, independente da forma clínica, entre os anos de 2000 a 2003. O total de abortamentos registrados foi de 2.286, sendo 459 (20,08%) na faixa etária da adolescência e a forma completa foi significativamente maior nas adolescentes quando comparada às das mulheres adultas; segundo o ano de análise, constatou-se decréscimo de ocorrência entre as adolescentes, com maior incidência em 2000 (30,50%), seguida dos anos de 2001 (25,05%), 2002 (23,53%) e 2003 (20,92%), sendo que as adolescentes apresentaram tendência a permanecer dois ou mais dias hospitalizadas. Enfatiza-se a implementação de políticas e programas direcionados à saúde sexual e reprodutiva e suas co-morbidades.

Abortamento na adolescência: da vida à experiência do colo vazio - um estudo qualitativo

O presente estudo teve como objetivo investigar o processo de abortamento na adolescência, segundo a perspectiva da adolescente. Foi desenvolvido no Hospital Maternidade Santa Izabel, da cidade de Bauru (São Paulo, Brasil), e a metodologia qualitativa buscou compreender a experiência da adolescente no processo de abortamento, construindo um modelo teórico representativo. Utilizou-se como referencial teórico o interacionismo simbólico e como metodológico a grounded theory. Foram entrevistadas dez adolescentes, e a análise dos relatos constatou a descoberta da gravidez, os sentimentos emergentes, o difícil momento da internação, a esperança do retorno ao cotidiano acompanhado pelo apoio dos familiares e a necessidade de mudanças decorrentes de tal experiência. Dos depoimentos emergiram três fenômenos: descobrindo-se grávida, vivenciando o abortamento e reelaborando o plano de vida. A partir da análise do processo, desenvolveu-se a categoria central: Abortamento na adolescência: da vida à experiência do colo vazio. Conclusão: a ocorrência do abortamento na adolescência causa diferentes sentimentos, podendo atingir as esferas biopsicossociais.

Aquatic macrophyte distribution in relation to water and sediment conditions in the Itaipu Reservoir, Brazil

Aquatic macrophyte community distribution along the eastern shoreline of the Itaipu Reservoir (one of the South America's largest impoundments) is described in relation to limnological and sedimentological factors. The central body of the reservoir is mesotrophic, while the arms (flooded influent river valleys) along the eastern shore may be oligo-mesotrophic to eutrophic, depending on time of year and sub-catchment characteristics. Macrophyte community composition and species cover were surveyed at 30 sites in four arms, in relation to sediment total P and organic matter; underwater light regime; and water total P and Kjeldahl N concentration, alkalinity, conductivity, depth and pH. Seventeen euhydrophyte and six emergent macrophyte species were recorded. Large stands of Egeria najas dominated the euhydrophyte vegetation, together with free-floating weed species (Pistia stratiotes Linn., Salvinia auriculata Aublet and Eichhornia crassipes (Mart.) Solms.). Canonical Correspondence Analysis of the data showed that two sets of variables were important predictors of aquatic macrophyte community structure. Floating macrophyte assemblage was closely related to concentration of nutrients in both water and sediment, while light penetration was the strongest predictor of submerged species occurrence. Although a large number of potential nuisance species were present, dense growths were restricted to shallower areas of the Itaipu Reservoir, causing localised problems. The possibility of increasing interference by these plants with fisheries, recreational use, transport and hydroelectricity generation suggests a need for continued monitoring of weed distribution and abundance, and investigation of appropriate management measures.

Strontium zirconate heterogeneous catalyst for biodiesel production: Synthesis, characterization and catalytic activity evaluation

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Geochemical Assessment of a Subtropical Reservoir: A Case Study in Curitiba, Southern Brazil

Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro-, trace- and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long-term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Parana State, in the South-Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP-OES, ICP-MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed.

Apatite coatings onto titanium surfaces submitted to laser ablation with different energy densities

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Synthesis and functionalization of magnetite nanoparticles with different amino-functional alkoxysilanes

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A Metacommunity Framework for Enhancing the Effectiveness of Biological Monitoring Strategies

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Bioactive coating on titanium implants modified by Nd:YVO4 laser

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)