Objective. To describe the prevalence of burnout syndrome among intensive care physicians in Salvador, Brazil, and analyze it for associations with demographic data and aspects of their working conditions (psychological demands and control over tasks).MethOds. This was a cross-sectional study investigating associations between psychosocial aspects of work and professional burnout in a population of 297 intensive care physicians in Salvador. A selfadministered individual questionnaire was used to collect data on psychosocial features of work using the demand-control model (Job Content Questionnaire) and on the mental health of the physicians using the Maslach Burnout Inventory (MBI).Results. An elevated level of working hours overload and on-call work overload was observed. The prevalence of professional burnout was 7.4% and was more strongly associated with the psychological demands of work than with intensive care physician's control over that work. cOnclusiOns. Physicians doing highly demanding work (many demands and little control) suffered 10.2 times more burnout than those with undemanding work (few demands and a high degree of control).

The objectives of this study were to investigate leaf breakdown in two reaches of different magnitudes, one of a 3 rd (closed riparian vegetation) order and the other of a 4 th (open riparian vegetation) order, in a tropical stream and to assess the colonization of invertebrates and microorganisms during the processing of detritus. We observed that the detritus in a reach of 4 th order decomposed 2.4 times faster than the detritus in a reach of 3 rd order, in which, we observed that nitrate concentration and water velocity were greater. This study showed that the chemical composition of detritus does not appear to be important in evaluating leaf breakdown. However, it was shown to be important to biological colonization. The invertebrate community appeared not to have been structured by the decomposition process, but instead by the degradative ecological succession process. With regards to biological colonization, we observed that the density of bacteria in the initial stages was more important while fungi appeared more in the intermediate and final stages.

Médicos plantonistas de unidade de terapia intensiva: perfil sócio-demográfico, condições de trabalho e fatores associados à síndrome de burnout

Riparian vegetation provides the nutrient and energy input that maintains the metabolism and biodiversity in tropical headwater streams. In the present study, it was hypothesised that ~30% of riparian plant species contribute over 70% of coarse particulate organic matter and, because tropical plants are perennial and semi-deciduous, it was expected that leaf fall would occur year round. The aims of the present study were to evaluate the composition and structure of the plant riparian zone and the input and associated benthic stock of organic matter. The riparian vegetation was composed of 99 taxa. The most abundant plant species were Tapirira obtusa, Sclerolobium rugosum, Croton urucurana, Byrsonima sp. and Inga sp. The input and benthic stock showed a seasonal pattern, with higher values recorded at the end of the dry season and at the beginning of tropical storms. The biomass contributed monthly by the vegetation ranged from 28 ± 6 g m–2 to 38 ± 11 g m–2, and the mean monthly benthic standing stock was 138 ± 57 g m–2. The results illustrate the importance of riparian vegetation as an energy source to tropical streams and how individual plant species contribute to organic matter inputs in these ecosystems.

The relationship between leaf breakdown and colonisation by invertebrates in tropical aquatic ecosystems is poorly understood, especially in regard to the added problem of the potential effects of exotic species. To assess the colonisation by invertebrates during leaf breakdown in a third-order headwater stream in south-eastern Brazil, we conducted an experiment using the native species Miconia chartacea, the exotic species Eucalyptus grandis and artificial leaves. We hypothesised that the quality of the detritus and the leaf shape influence invertebrate colonisation because of the quality of the food and refuge offered by leaf detritus. Invertebrate density and richness were higher on leaves of E. grandis than on those of M. chartacea. Taxon richness did not differ among M. chartacea and the two sizes of artificial leaves offered, probably as a function of the chemical composition of E. grandis. Total invertebrate density was significantly higher in the organic detritus, suggesting that detritus provides food for the organisms. Our results indicate that the colonisation of invertebrates is probably affected by the chemical composition of detritus. Contrary to expectations, the community of invertebrates had no difficulty in colonising E. grandis, although it is an exotic species. In addition, the shredder activity did not influence leaf breakdown. These results may indicate that the invertebrates in this stream tend to behave as generalist feeders.

ABSTRACT

Damming disrupts lotic continuity, creating a lentic water body upstream of the dam and a lotic stretch downstream that is highly vulnerable to temporal fluctuations in flow and physiochemical quality depending on the operational regime of the dam. Thus, an essential part of any dam operation programme must take into account a typologically suitable environmental flow regime, in order to maintain downstream structure and function. We assessed the seasonal impact of daily flow peaking regimes on the taxonomic composition, metrics and traits of the macroinvertebrate community in the lotic section situated downstream of the Itutinga reservoir on the Rio Grande in the state of Minas Gerais in southeast Brazil. The flow manipulation experiments were carried out in both wet (January) and dry periods (July) of 2010. The samplings were carried out in two hydraulic situations (fixed flow and daily flow peaking). Benthic macroinvertebrates and sediment were collected in three habitat types (backwater, fluvial beach and running water). Water variables were measured only in the fluvial beach habitat. Both water column and sediment variables downstream were heavily influenced by the retention capacity of the reservoir rather than the daily flow peak value. The trait approach was more sensitive than abundance and metrics and could detect the effects of daily flow peaking. The benthic macroinvertebrate communities sampled downstream of the Itutinga reservoir were more influenced by the sediment composition at each of the three studied habitats, than by the tested daily flow peaking. However, given the short timescale of this study, it may be difficult to the influence of these two interrelated factors. Copyright © 2013 John Wiley & Sons, Ltd.

Most Latin American demands for drinking water are in or near urban areas. However, population growth and untreated sewage disposal degrade water quality, with negative effects for biodiversity and ecosystem services. Mobilizing society to monitor quality of urban watercourses facilitates training and allows diagnosis that may further help implement mitigation and management strategies. Therefore, our research was conducted in a [ 4000 km 2 metropolitan region of high human influence. Urban water body assessments were conducted by 1965 teachers and students and their consistency validated by rigorous scientific methods. The assessments revealed degradation of physical habitat, water quality, or biology in 91% of the evaluated urban stream sites. Increased knowledge concerning environmental stressors and biological responses by local citizens may increase their participation in public policy development and implementation. We conclude that participatory scientific monitoring is a viable way for improving science education, increasing social participation, and improving the ecosystem services provided by urban watercourses.