Spatial variations in fish assemblage structure in a southeastern Brazilian reservoir / Variações espaciais na estrutura das assembléias de peixes em um reservatório do sudeste do Brasil

Abstract We assessed the fish assemblage structure and composition of Nova Ponte Reservoir (Araguari River, Upper Paraná Basin, Brazil). We observed significant differences in abundance (p = 0.0003), richness (p = 0.0005) and diversity (p = 0.02) between lacustrine and riverine zones of the reservoir. Nine species were significantly more abundant in the riverine region: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. The results indicated a longitudinal gradient in the composition and abundance of fishes in Nova Ponte Reservoir, reinforcing the importance of freely flowing riverine reaches for conserving native neotropical ichthyofauna and reflecting the strong adaptation of these species to riverine systems.

Resumo Este estudo avaliou a assembléia de peixes do reservatório de Nova Ponte (rio Araguari, bacia do Alto Paraná, Brasil), em termos de estrutura e composição. Foram observadas diferenças significativas na abundância (p = 0.0003), riqueza (p = 0.0005) e diversidade (p = 0.02) entre as zonas lacustres e fluviais do reservatório. Nove espécies foram mais abundantes na região fluvial: Astyanax altiparanae, Astyanax gr. fasciatus, Galeocharax knerii, Hoplias intermedius, Hypostomus sp., Leporinus friderici, Leporinus obtusidens, Pimelodus maculatus and Schizodon nasutus. Os resultados indicaram a existência de um gradiente longitudinal na composição e abundância de peixes no reservatório de Nova Ponte. Estes padrões reforçam a importância de trechos fluviais livres de barramentos para a conservação da ictiofauna neotropical nativa e refletem a forte adaptação dessas espécies aos sistemas fluviais.

Hypofractionated radiotherapy for localized prostate cancer using three‑dimensional conformal radiotherapy technique: 3 years toxicity analysis.

BACKGROUND: Hypofractionated radiotherapy in the radical treatment of localized prostate cancer has potential biological advantages relative to conventional fractionation. We report prospectively collected toxicity data from a cohort of patients treated with a 3D conformal technique (3DCRT). MATERIALS AND METHODS: 90 patients receiving curative intent hypofractionated radiotherapy with 57Gy in 19 daily fractions over 3.8 weeks were evaluated prospectively for the development of radiation related toxicity over a 3 year period. RESULTS: All patients completed treatment. Maximal acute toxicity experienced was 58.6, 10 and 1.1% for grade 1, 2 and 3 genitourinary (GU) toxicity respectively and 75.6, 9 and 0% for gastrointestinal (GI) toxicity. For late toxicity the three year actuarial rates of grade 1, 2 and 3 GU and GI toxicity respectively were 47.3, 2.4 and 0%; and 40, 9.3 and 4.7%. There were no grade 4 or worse acute or late toxicities. 97.6% of evaluable patients remained free of biochemical failure 36 months post radiotherapy. CONCLUSIONS: A 57Gy in 19 daily fraction radiotherapy schedule using 3D conformal radiotherapy for the definitive treatment of localized prostate cancer has acceptable early and late toxicity.

Influence of peak flow changes on the macroinvertebrate drift downstream of a Brazilian hydroelectric dam / Influência de alterações de vazão sobre a deriva de macroinvertebrados a jusante de uma barragem hidrelétrica brasileira

Successive daily peak flows from hydropower plants can disrupt aquatic ecosystems and alter the composition and structure of macroinvertebrates downstream. We evaluated the influence of peak flow changes on macroinvertebrate drift downstream of a hydroelectric plant as a basis for determining ecological flows that might reduce the disturbance of aquatic biota. The aim of this study was to assess the influence of flow fluctuations on the seasonal and daily drift patterns of macroinvertebrates. We collected macroinvertebrates during fixed flow rates (323 m3.s1 in the wet season and 111 m3.s1 in the dry season) and when peak flows fluctuated (378 to 481 m3.s1 in the wet season, and 109 to 173 m3.s1 in the dry season) in 2010. We collected 31,924 organisms belonging to 46 taxa in the four sampling periods. Taxonomic composition and densities of drifting invertebrates differed between fixed and fluctuating flows, in both wet and dry seasons, but family richness varied insignificantly. We conclude that macroinvertebrate assemblages downstream of dams are influenced by daily peak flow fluctuations. When making environmental flow decisions for dams, it would be wise to consider drifting macroinvertebrates because they reflect ecological changes in downstream biological assemblages.

Os sucessivos pulsos diários de vazão decorrentes da operação de usinas hidrelétricas podem perturbar os ecossistemas aquáticos e alterar a composição e estrutura de macroinvertebrados a jusante de barramentos. Nós avaliamos a influência de alterações de vazão sobre a deriva de macroinvertebrados a jusante de uma barragem hidrelétrica como subsídio para a determinação de vazões ecológicas que podem reduzir os distúrbios sobre a biota aquática. O objetivo deste estudo foi avaliar a influência das flutuações de vazão sobre os padrões sazonais e diários de deriva de macroinvertebrados. Nós coletamos os macroinvertebrados durante períodos de vazão fixa (323 m3.s1 na estação de chuvas e 111 m3.s1 na estação seca) e com flutuações de vazão (378 - 481 m3.s1 na estação de chuvas e 109 - 173 m3.s1 na estação seca) no ano de 2010. Foram coletados 31.924 organismos distribuídos em 46 taxa nos quatro períodos amostrais. A composição taxonômica e a densidade de invertebrados a deriva diferiram entre os períodos com vazão fixa e flutuante, tanto na estação de chuvas quanto na seca, mas a riqueza taxonômica não variou significativamente. Em conclusão, as comunidades de macroinvertebrados a jusante de barragens são influenciadas pelas flutuações diárias na vazão. Portanto, os macroinvertebrados a deriva devem ser considerados nos cálculos de vazões ambientais, pois eles claramente refletem as mudanças ecológicas nas comunidades biológicas a jusante de barragens hidrelétricas.

Acute congestive heart failure secondary to an unusual underlying cause.

We report a patient who presented with non-specific features and rapidly developed multisystem disease as a result of Chrug-Strauss syndrome, a rare diffuse primary vasculitis. This case report highlights the importance of considering primary vasculitides as a differential diagnosis in patients presenting with multiple organ involvement as early specific therapy in such cases has shown to change the outcome.

Indispensable benefits and unavoidable costs of unattended sound for cognitive functioning.

Critical to survival, and also to the organism's efficient management of the flow of information in the brain, is attentional selectivity; the ability to select one source of information to guide action whilst ignoring others that are irrelevant to the current behavioural goal. But such selectivity is not merely the inclusion of the relevant information and the complete neglect of irrelevant information. We discuss in this paper the way that all sound is processed in an obligatory fashion--whether relevant or irrelevant--and discuss the fate of sound in the case when it is irrelevant to the immediate mental task. Using the so-called irrelevant sound paradigm we show that unattended information is both registered and organised. This obligatory process of organisation compromises the efficiency of particular types of mental activity. We discuss how such interference comes about but the key emphasis is upon the possible beneficial effects of such processing-of-the-irrelevant, in allowing the switching of attention to be more facile and intelligent and in allowing the accumulation of evidence about statistical regularities in the auditory world (such as those helpful to the efficient perception, acquisition and use of language). In sum, we describe how purposeful processing based on directed attention is in a state of tension with the obligatory, automatic processing of the unattended. One of the consequences of this tension is typically manifested in auditory distraction, but the benefits of processing of the attended may considerably outweigh this disadvantage.