Session B4- Studies on fish passage at ltaipu Dam

The Piracema Canal is a 10.3 km long fishway with a total elevation gain of 120m. It is located at the Itaipu Dam, on the Parana River between Brazil and Paraguay. The Canal comprises a natural stream, the Bela Vista River (6.8 km long) and an artificial subsystem (technical reaches and lakes; last 3.5 km). Most of the migratory species caught below the Itaipu Dam were captured in the Bela Vista River, some in high abundance. Studies conducted with different fishing gears indicate that few individuals reach the upper end of the system, with rates estimated at 0.5% (using gillnets), 1.6% (radiotelemetry) and 18.4% (PIT -tag telemetry). This range of results may be attributed to methodological variations, or to different periods in which these studies were conducted. The segment called Drainage Channel (200m long, 6% slope and turbulent) represents the transition from the natural to the artificial subsystem; this section appears to act as a barrier to fish passage, conferring selectivity to the system. Tagged fish below the Drainage Channel took on average 10 days longer to reach the end of the system than the tagged fish just above this segment. The long time span taken by migratory fish to ascend suggests that they may be using the system mainly for dispersal, but all individuals have potential to spawn in the next reproductive season, because earlier studies clearly demonstrate that they can find the spawning places located upstream Itaipu Reservoir. Therefore, the Piracema Canal contributes to the biodiversity conservation of potamodromous fish in the last lotic stretch of the Parana River inside the Brazilian territory

Influência da urbanização sobre as assembléias de peixes em três córregos de Maringá, Paraná Influence of urbanization upon fish assemblages in three streams of Maringá, Paraná

O objetivo do presente estudo foi avaliar padrões espaciais na composição, estrutura e distribuição das assembléias de peixes e suas relações com características abióticas em três córregos urbanos da cidade de Maringá, Paraná, Brasil. Peixes foram coletados ao longo de um gradiente longitudinal utilizando pesca elétrica nos meses de maio e novembro de 2004. Temperatura, nitrogênio, pH, oxigênio e fósforo foram as variáveis que mais influenciaram a análise de componentes principais (CPA). Riqueza, eqüitabilidade, índice de diversidade de Shannon-Wiener e o primeiro eixo da análise de correspondência com remoção do efeito do arco (DCA) foram diretamente correlacionados com características ligadas ao impacto químico urbano. Adição de espécies prevaleceu nas estações de amostragem do córrego Miosótis e entre a cabeceira e porção intermediária nos córregos Nazaré e Mandacaru. Substituição ocorreu entre as porções intermediárias e foz desses córregos. A dominância da espécie tolerante Poecilia reticulata Peters, 1859 indicou a influência do impacto do meio urbano sobre as assembléias de peixes.<br>The aim of the present study was to evaluate spatial patterns in composition, structure and distribution of fish assemblages and their relationships with abiotic characteristics in three urban streams of Maringá city, Paraná, Brazil. Fish were collected along the longitudinal gradient by electrofishing in May and November 2004. Temperature, nitrogen, pH, oxygen and phosphorous influenced at most the principal components analysis (PCA). Richness, evenness, Shannon-Wiener index and the first axis of detrended correspondence analysis (DCA) were directly correlated with abiotic characteristics related to chemical urban impact. Species addition prevailed in Miosotis stream sampling stations, and between headwater and intermediary reaches in Nazaré and Mandacarú streams. Replacement occurred between intermediary and lowland reaches of these streams. The dominance of the tolerant species Poecilia reticulata Peters, 1859 indicated the influence of the urban impact on fish assemblages

B-type natriuretic peptide and C-reactive protein in the prediction of atrial fibrillation risk: the CHARGE-AF Consortium of community-based cohort studies

AIMS: B-type natriuretic peptide (BNP) and C-reactive protein (CRP) predict atrial fibrillation (AF) risk. However, their risk stratification abilities in the broad community remain uncertain. We sought to improve risk stratification for AF using biomarker information. METHODS AND RESULTS: We ascertained AF incidence in 18 556 Whites and African Americans from the Atherosclerosis Risk in Communities Study (ARIC, n=10 675), Cardiovascular Health Study (CHS, n = 5043), and Framingham Heart Study (FHS, n = 2838), followed for 5 years (prediction horizon). We added BNP (ARIC/CHS: N-terminal pro-B-type natriuretic peptide; FHS: BNP), CRP, or both to a previously reported AF risk score, and assessed model calibration and predictive ability [C-statistic, integrated discrimination improvement (IDI), and net reclassification improvement (NRI)]. We replicated models in two independent European cohorts: Age, Gene/Environment Susceptibility Reykjavik Study (AGES), n = 4467; Rotterdam Study (RS), n = 3203. B-type natriuretic peptide and CRP were significantly associated with AF incidence (n = 1186): hazard ratio per 1-SD ln-transformed biomarker 1.66 [95% confidence interval (CI), 1.56–1.76], P < 0.0001 and 1.18 (95% CI, 1.11–1.25), P < 0.0001, respectively. Model calibration was sufficient (BNP, χ(2) = 17.0; CRP, χ(2) = 10.5; BNP and CRP, χ(2) = 13.1). B-type natriuretic peptide improved the C-statistic from 0.765 to 0.790, yielded an IDI of 0.027 (95% CI, 0.022–0.032), a relative IDI of 41.5%, and a continuous NRI of 0.389 (95% CI, 0.322–0.455). The predictive ability of CRP was limited (C-statistic increment 0.003). B-type natriuretic peptide consistently improved prediction in AGES and RS. CONCLUSION: B-type natriuretic peptide, not CRP, substantially improved AF risk prediction beyond clinical factors in an independently replicated, heterogeneous population. B-type natriuretic peptide may serve as a benchmark to evaluate novel putative AF risk biomarkers