Microhabitat preferences in springs, as shown by a survey of nematode communities of Trentino (south-eastern Alps, Italy)

Ninety-four Alpine springs in Trentino, from 170 to 2792 m a.s.l., were studied and compared for their nematode communities. No nematode species appeared typical for Alpine springs (crenobionts or crenophiles); all the identified species were common in freshwater habitats, with a wide geographical range on a continental scale. The only notable, rare species was Eumonhystera tatrica Daday, 1896, a very small nematode that has apparently never been found since it was first described. Eighty springs with more than 7 specimens were retained for statistical analysis. Distinctness indices \uce\u94+ and \uce\u9b+ showed that only a few springs exceeded the funnel limits for such indices. The relationships between habitat features and community composition, and nematode ecology (c-p value, size, trophy) were investigated. The major abiotic factors influencing nematode community composition were water temperature and lithology (carbonate vs. crystalline). In addition, nematode communities from mosses differed from those sampled from other substrata in the same spring. The nematode-based Maturity Index increased with crenic water temperature, in contrast to other indices, such as Shannon diversity and Berger-Parker index, suggesting that r-strategist nematode species replace K-strategists along the temperature gradient. Lithology did not alter species richness, but the relative abundance of species present on carbonate and in non-carbonate substrata varied. The 4th-corner analysis showed significant correlations between temperature and species trophic group. In conclusion, nematodes are good ecological indicators of polluted vs unpolluted waters, but, at least in this case, cannot be used to differentiate between unpolluted habitats such as Alpine springs

Nematodes and rotifers on two Alpine debris-covered glaciers

Debris-covered glaciers (DCGs) are glaciers whose ablation area is mostly covered by a continuous layer of debris, and are considered to be among the continental glacierized environments richest in life. DCG colonization by microorganisms, plants and animals, has been investigated in a few studies, while the meiofauna (metazoans smaller than 2\uc2\ua0mm) of these environments has been neglected so far. In this study, we analyzed nematode and rotifer fauna on the two largest debris-covered glaciers of the Italian Alps: the Miage Glacier and the Belvedere Glacier. In total, we collected 38 debris samples on the glaciers in July and September 2009. All the rotifers we found belonged to the bdelloid Adineta vaga (Davis, 1873). Nematodes belonged to 19 species. Miage Glacier hosted a richer and more diverse nematode fauna than the Belvedere. The dominant genus was Plectus Bastian, 1865, a common genus in habitats at high latitude and altitude. Analysis of the feeding type of nematodes highlighted that bacterivores were dominant on Miage Glacier, while bacterivores and herbivores were more widespread on Belvedere Glacier. Predator nematodes were absent. Analysis of the food-web structure indicated that nematode assemblages on both glaciers were typical of environments with depleted food availability, probably resulting from instability of the glacier surface and the short exposure of sediments, preventing the evolution of true soil and enrichment in organic matter of the debris. The scarcity of bacterial primary producers suggests that deposition of allochthonous organic matter is the principal organic carbon source in this environment

X-ray microscopy of living multicellular organisms with the Prague Asterix Iodine Laser System

Soft X-ray contact microscopy (SXCM) experiments have been performed using the Prague Asterix Iodine Laser System (PALS). Laser wavelength and pulse duration were λ = 1.314 μm and τ (FWHM) = 450 ps, respectively. Pulsed X rays were generated using teflon, gold, and molybdenum targets with laser intensities I ≥ 1014 W/cm2. Experiments have been performed on the nematodes Caenorhabditis elegans. Images were recorded on PMMA photo resists and analyzed using an atomic force microscope operating in contact mode. Our preliminary results indicate the suitability of the SXCM for multicellular specimens

Mortalidade infantil e acesso geográfico ao parto nos municípios brasileiros

OBJETIVO: Analisar o acesso geográfico ao parto hospitalar nos municípios brasileiros. MÉTODOS: Foram analisadas informações de óbitos e nascimentos quanto à sua adequação para o cálculo do coeficiente de mortalidade infantil no período de 2005 a 2007 para os 5.564 municípios brasileiros. O acesso geográfico foi expresso por indicadores de deslocamento, oferta e acesso aos serviços de saúde. A associação entre o acesso geográfico ao parto e o coeficiente de mortalidade infantil em municípios com adequação de suas informações vitais foi avaliada por meio de regressão múltipla. RESULTADOS: Dentre os municípios analisados, 56% apresentaram adequação das informações vitais, correspondendo a 72% da população brasileira. O deslocamento geográfico ao parto mostrou-se inversamente associado ao porte populacional, à renda per capita, e à mortalidade infantil, mesmo controlado por fatores demográficos e socioeconômicos. CONCLUSÕES: Embora tenham sido desenvolvidas estratégias importantes para a melhoria da qualidade do atendimento às gestantes no Brasil, as ações para garantir o acesso igualitário à assistência ao parto ainda são insuficientes. O maior deslocamento intermunicipal para o parto se mostrou como um fator de risco para a mortalidade infantil, aliado à desigualdade de oferta de serviços qualificados e à falta de integração com a atenção básica de saúde

Redescription of three tobrilids (Nematoda) from Alteherr`s collection using confocal microscopy

Three species (Eutobrilus andrassyi, E. husmanni, Epitobrilus setosus) erected by Altherr are redescribed from the original specimens of his collection. New data are provided also with the aid of the confocal microscopy, owing to the natural fluorescence of these nematodes

Morphological differences between free-living soil and freshwater nematodes in relation to their environments

There is no single feature to distinguish free-living soil nematodes from freshwater nematodes, also because all free-living nematodes are essentially aquatic. This notwithstanding, by examining the frequencies of some characters of 1141 European species, differences of qualitative/quantitative characters between soil and freshwater nematodes were found. In particular, aquatic and semiaquatic species are, on average, longer and slimmer than soil species, have a longer tail, greater body weight, smooth cuticle and larger amphids. A new body parameter, length of the pharynx in relation to the length of the whole digestive tract (e), was also taken into consideration