Samples of 7 species of piscivorous, omnivorous, and herbivorous fish caught at 12 different sites on the Madeira River, Amazon Basin, were analyzed for selenium and mercury. Selenium was determined by anodic stripping voltammetry and mercury by cold vapor atomic absorption spectrophotometry. The means for selenium concentrations ranged from 0.49 to 3.11 nmol/g and for mercury from 0.41 to 6.66 nmol/g depending on the fish species. The molar ratios of Hg:Se increased according to the fish trophic level. Piscivorous species had the highest mean ratio (4.0) and herbivorous species the lowest (0.9). There was a positive and statistically significant correlation between selenium and mercury concentrations for the herbivorous species (r = 0.716; p = 0.0088) not seen for omnivororus and piscivorous species (r = -0.2032; p = 0.3407). These findings are significant for the fish-eating population of the Madeira River because the ingestion of mercury would always be in excess of selenium.
Pesq. Vet. Bras. 32(Supl. Electrocardiography can be used to quantify the training and athletic performance as well as evaluating the cardiac function under the effect of exercise identifying the influence of cardiac anomalies, and deleterious effects of stress ahead of heart function. Considering the complexity of the physical efforts inherent in polo ponies in competitions, together with the lack of reports in the literature, on the demand resulting for heart. The aim of this study was to identify and evaluate the cardiac effects of electrocardiographic exercise in polo horses in order to support data for understanding the physiological cardiac demand of this sport. We evaluated 27 equine practitioner polo at rest and between five and ten minutes after exercise. The results showed that the observed changes in the duration and P wave amplitude and duration of PR and QT interval were considered in physiological response to increased heart rate. The diphasic P wave found at rest and when atrial hypertrophy represented bifida represented different points of activation of the sinoatrial node. As expected, the QRS complex has not undergone major changes. The ST-segment elevation and T wave changes observed after exercise could pose adverse effects to the myocardium, but studies examining multiple factors are needed to confirm this association and define your actual question. The increase in QTc suggested fatigue mild myocardial represented high heart demand for this type of exercise. The heart score showed that these animals were within the pattern of cardiac adaptation to a horse athlete. The rapid recovery of HR showed good conditioning of these animals. The pacemaker migration was observed in most animals proven to be a normal finding horse athlete. We observed a low incidence of changes in cardiac rhythm.INDEX TERMS: Cardiac function, electrocardiographic index, physiology exercise.
RESUMOForam examinados, por meio de eletrocardiografia, 14 equinos Puro Sangue Árabe, 12 machos e duas fêmeas, desclassificados por exaustão em provas de enduro entre 60 e 160km. Foi observado predomínio de taquicardia sinusal, seguido de arritmia sinusal e complexo atrial prematuro com a frequência cardíaca variando de 48 a 78bpm e 93 a 111bpm, respectivamente. Ocorreu aumento da amplitude das ondas P, R, S e T e redução nas suas durações, bem como redução nos intervalos e segmentos, porém o complexo QRS quase não se alterou. O alongamento observado do QTc indicou fadiga miocárdica moderada em resposta ao exercício, e o supradesnível ST foi indicativo de hipovolemia. O eixo elétrico no plano frontal apresentou desvio à direita, aumento de câmara e hipertrofia secundários ao treinamento.
The time that the concrete must keep its properties, known as service life, it is an important design parameter for the performance of concrete structures. A porous concrete has a higher degree of water and aggressive permeability agents, which can cause deterioration of the reinforcement for mechanisms such as corrosion, besides not ensuring the watertightness, for example, on slabs under negative hydrostatic pressure (anti-flotation slabs). This type of slab has been used for the purpose of enabling or facilitating constructive actions associated with structures located beneath the groundwater table. There are several advantages of this type of construction: reduction of environmental impacts as it prevents the installation of permanent submersible pump systems, which reduces the use of electricity; nonoccurrence of settlement caused by the lowering of the groundwater table, which extends to the nearby areas of the construction site; and less impact to the groundwater table, which has serious consequences on the availability of this resource in urban areas. This paper presents a case study on the concreting of an anti-flotation slab, 30 cm thick and volume of 750 m 3 , of reinforced concrete, in a mixed use residential/commercial building, located in Northwest Sector, Brasilia, Brazil. To ensure the watertightness of this anti-flotation slab, a permeabilityreducing admixture was used to prevent hydrostatic condition, known for its ability to promote the sealing of cracks up to 0.4 mm by self-healing phenomenon. The results showed that both the composition of the concrete (containing permeability-reducing admixture) and setting the appropriate constructive strategies were essential to ensure an intact and tight structure.
Foi avaliado o comportamento da osmolaridade, do ânion gap, do pH e dos íons plasmáticos mensuráveis de 14 equinos, 9 machos e 5 fêmeas, Puro Sangue Árabe finalistas em provas de enduro de 90 km. Para tanto, foram colhidas em dois momentos (repouso e após o exercício prolongado) amostras de sangue venoso para a mensuração dessas variáveis. Pode-se verificar, a partir do repouso, aumento significativo dos valores do Hct, das PPT e do AG, sugerindo perda de fluidos e discreto grau de desidratação. O pH e o íon H+ quase não se alteraram, indicando ausência de distúrbios metabólicos. Reduções com diferenças significativas foram observadas para os íons Cl-, HCO3-, K+, Ca++, assim como do EB. Pode-se então, sugerir que o tipo de exercício a que os animais foram submetidos foi compatível com a capacidade atlética e ainda que a suplementação durante a competição contribuísse para minimizar tais perdas.
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