Hydropower affects fish trophic structure both downstream of the dam and upstream of the reservoir

Dams often cause drastic changes in freshwater environments and can compromise the quality and availability of food resources in rivers. This study aims to analyze the influence of a dam on the trophic structure of fish assemblages in lotic areas located both upstream and downstream of the Irapé Hydroelectric Power Plant. Fish sampling occurred before (2003 to 2005) and after (2011 to 2017) the impoundment, which began in 2006. The trophic structure and species composition before dam construction were similar upstream of the reservoir and downstream of the dam. After the building of the dam, both aspects of the assemblages changed along the lotic stretches - the upstream incurred an increase in biomass of detritivores and a decrease of piscivores and omnivores, while downstream went exactly the opposite, causing a differentiation between the two assemblages. Because lotic areas upstream of reservoirs are also impacted by river damming, efforts for impact mitigation should also focus on these areas.(AU)

Barragens causam mudanças drásticas em ambientes de água doce e podem comprometer a qualidade e a disponibilidade de recursos alimentares nos rios. Este estudo teve como objetivo analisar a influência de uma barragem na estrutura trófica da assembleia de peixes em áreas lóticas localizadas a montante e a jusante da usina hidrelétrica de Irapé. A amostragem de peixes ocorreu antes (2003 a 2005) e após (2011 a 2017) o fechamento das comportas, iniciado em 2006. A estrutura trófica e a composição das espécies antes da construção da barragem eram semelhantes a montante do reservatório e a jusante da barragem. Após a construção da barragem, ambos os aspectos das assembleias mudaram ao longo dos trechos lóticos - a montante ocorreu um aumento na biomassa de detritívoros e diminuição de piscívoros e onívoros, enquanto a jusante ocorreu exatamente o oposto, causando uma diferenciação entre as duas assembleias. Como as áreas lóticas a montante dos reservatórios também são impactadas por barramentos, esforços para mitigação de impactos também devem se concentrar nessas áreas.(AU)

Comparative study to evaluate the effect of l-carnitine plus glimepiride versus glimepiride alone on insulin resistance in type 2 diabetic patients.

AIM: Insulin resistance (IR) is predominant in type 2 diabetic patients. This study aimed to investigate benefits from adding l-carnitine to ongoing glimepiride compared to glimepiride monotherapy on IR in diabetic patients who failed to achieve their glycemic goals on glimepiride monotherapy. METHODS: 58 patients were recruited from Internal Medicine Department, Tanta University Hospital, Egypt then prospectively randomized to receive their glimepiride dose 2 mg twice daily (group 1) or glimepiride 2 mg twice daily + l-carnitine 1 g m twice daily (group 2) for 6 months. Fasting blood samples were collected at baseline, 3 and 6 months after treatment for analysis of fasting and postprandial blood glucose [FBG &PPBG], glycated hemoglobin [HbA1c %], fasting insulin, extracellular part of insulin regulated aminopeptidase [IRAPe] as a novel marker, tumor necrosis factor-alpha [TNF-α], visfatin and lipid panel. Body mass index [BMI] and homeostasis model assessment of insulin resistance [HOMA-IR] were calculated. Data were statistically analyzed by SPSS using unpaired Student's t-test and one way analysis of variance; p ≤ 0.05 was considered statistically significant. RESULTS: The obtained data suggested that adding l-carnitine to glimepiride has a significantly beneficial effect on FBG, PPBG, HbA1c, fasting insulin, HOMA-IR index, IRAPe, TNF-α, visfatin and lipid panel parameters but doesn't have effect on BMI and blood pressure. CONCLUSION: The co-administration of l-carnitine with glimepiride represents a new therapeutic strategy for better controlling diabetic patients as it resulted in more beneficial effects on direct and indirect biomarkers of insulin resistance than glimepiride alone.