Impacts on water, soil and plants from the abandoned Miguel Vacas copper mine, Portugal

Soil, water and plant geochemistry was studied around the Miguel Vacas copper mine (Alentejo, SE Portugal), which stopped its exploitation and processing activities in 1991. After closure waste-rock piles remained exposed to weathering. The copper ore was mainly composed of copper phosphates and carbonates. Remediation actions were insufficient to prevent the spreading of waste-rock materials to surrounding farmed fields. The latter caused contamination of soils and water. Based on overall characteristics water from wells and surface stream water mostly can be classified as of the sulphate magnesium type. The application of a chemical equilibrium model to the sampled water showed that copper, phosphate and sulphate concentrations are controlled by copper(II) secondary minerals (pseudomalachite, libethenite and malachite) and gypsum. Nevertheless, groundwater can be used for irrigation and cattle based on quality parameters. Soils and plants (Prunus domestica L., Olea europaea L. spp. europaea and Quercus ilex L.) were collected southeast of the open pit and the exploitation substructures. The soils located in the influence of drainage water that percolated through waste material or exploitation substructures were contaminated with Cu, and Ni was close to the maximum value allowed by Portuguese legislation. These soils, however, did not show elevated Zn and Mn concentrations. The trace element content in plants was within the normal range, with Q. ilex being able to accumulate Mn and to some extent also Ni. Dispersion of trace elements seemed to be limited to a distance 1500 m down from the waste dumps in southeastern direction

Occurrence of Salmonella spp. in eggs from backyard chicken flocks in Portugal and Romania - results of a preliminary study

The aim of this study was to conduct a preliminary investigation on the occurrence of Salmonella spp. in eggs from chickens raised in backyards in Portugal and Romania. A lack of compliance with safety practices by chicken owners, was demonstrated, especially in Portugal, as 96% of the eggs were visibly dirty and 92.5% were stored at room temperature. In Romania the 202 analysed eggs were Salmonella free, whereas in Portugal six of the 200 eggs sampled were positive for Salmonella spp. (3%). A positive egg for Salmonella spp. was found in 10.7% of the 56 backyard flocks sampled in Portugal. One egg exhibited contamination both in the shellmembrane mixture and in its content, while in the remaining eggs, the pathogen was found either in the shellmembrane (n = 2) or in the yolk and white mixture (n = 3). The serotypes S. Typhimurium (with identical PFGE patterns) and S. Enteritidis were isolated from five eggs and one egg, respectively. Whilst S. Enteritidis was sensitive to the 14 antibiotics tested, S. Typhimurium isolates presented divergent antimicrobial resistant phenotypes and three were classified as multi-drug resistant.info:eu-repo/semantics/acceptedVersio

Soliton generation by internal tidal beams impinging on a pycnocline: laboratory experiments

In this paper, we present the first laboratory experiments that show the generation of internal solitary waves by the impingement of a quasi-two-dimensional internal wave beam on a pycnocline. These experiments were inspired by observations of internal solitary waves in the deep ocean from synthetic aperture radar (SAR) imagery, where this so-called mechanism of 'local generation' was argued to be at work, here in the form of internal tidal beams hitting the thermocline. Nonlinear processes involved here are found to be of two kinds. First, we observe the generation of a mean flow and higher harmonics at the location where the principal beam reflects from the surface and pycnocline; their characteristics are examined using particle image velocimetry (PIV) measurements. Second, we observe internal solitary waves that appear in the pycnocline, detected with ultrasonic probes; they are further characterized by a bulge in the frequency spectrum, distinct from the higher harmonics. Finally, the relevance of our results for understanding ocean observations is discussed

Morphologic and systemic alterations in obese and overweight subjects after a physical activity intervention program

There are some evidences that exercise training reduces total and abdominal fat and some systemic variables with improve health benefits. The sim of this study was to ana1yse the variation of some morphologic and systemic variables in 16 (age-64.5±7.2) obese and overweight (BM!=31.4o±5.7) type 2 diabetic patieots, of hoth gender, dutiog a regular physical exercisc program, which consists of 3 5 minutes of fast walking every days of the week, during 8 months, and no diet intervention

Widespread hybridization between Invasive bleak (Alburnus alburnus) and Iberian chub (Squalius spp.): A neglected conservation threat

Hybridization between native and nonnative fish species is a major conservation issue, especially in ecosystems with high levels of endemism, such as Iberian streams. To date, hybridization with the invasive bleak Alburnus alburnus has been reported for the Iberian chub Squalius alburnoides and S. pyrenaicus and in scattered locations only. However, the bleak is spreading in the region, potentially increasing the risks of hybridization with other Squalius species. To gather a more comprehensive picture on the current geography of hybridization, we compiled records on hybrids between bleak and chub in Portugal and conducted genetical assessments of hybrids between bleak and S. carolitertii. We found that hybridization with bleak is widespread throughout Portuguese river basins and involves at least S. alburnoides, S. pyrenaicus and S. carolitertii. Hybridization with bleak may not only cause waste of reproductive effort and damage the genetic integrity of these endemic species but also promote shifts in the reproductive dynamics of the S. alburnoides hybrid complex, which includes individuals with various ploidy levels and combinations of parental genomes, reproducing sexually and asexually. We recommend that future studies characterize the fitness of bleak hybrids and their ecological and genetic interactions with native fish, in order to design effective conservation measures

Fontes orgânicas de nutrientes em sistemas de produção de batata.

Nos últimos anos, diminuiu muito o número de bataticultores na região da Quarta Colônia, no centro do Estado do Rio Grande do Sul (RS), devido ao elevado risco econômico na produção da batata. A partir de uma demanda da Associação dos Produtores de Batata da Região Central do Rio Grande do Sul (ASBAT), foram instalados experimentos visando a avaliar, técnica e economicamente, fontes orgânicas alternativas à adubação mineral tradicional dos produtores de batata, objetivando diminuir os custos de produção e o impacto do seu cultivo no ambiente. Foram estabelecidas rotações envolvendo culturas comerciais e plantas de cobertura de solo para o cultivo da batata na safra e na safrinha. As fontes de nutrientes foram camas de frango e de suínos e adubo mineral tradicionalmente utilizado pelos bataticultores. Os resultados mostraram que a utilização de fontes orgânicas de nutrientes no cultivo da batata é uma alternativa viável técnica e economicamente. Contudo, sua eficiência pode ser maximizada quando associada com a adubação mineral, especialmente para aumentar a quantidade de nitrogênio disponível desde o início do ciclo da cultura e isso é particularmente importante quando do uso da cama de suínos. A cama de frango, por conter maior quantidade de nutrientes, é uma alternativa melhor do que a cama de suínos, tanto técnica quanto economicamente

Qualidade da Preparação Intestinal: Um desafio para todos

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Qualidade da Preparação Intestinal: Um desafio para todos

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