493 research outputs found

    On the occurrence of the silverstripe blaasop Lagocephalus sceleratus (Gmelin, 1789) along the Libyan coast

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    Five individuals of Lagocephalus sceleratus were caught by trammel and gill nets off Ain Al Ghazala, Libya (approximately 32°09'N − 23°15'E) between 15 and 25 m depth in September 2010. Our findings represent the first record of this toxic species from Libya and provide further evidence of its occurrence along North African coasts

    Effects of ocean acidification on embryonic respiration and development of a temperate wrasse living along a natural CO2 gradient

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    Volcanic CO2 seeps provide opportunities to investigate the effects of ocean acidification on organisms in the wild. To understand the influence of increasing CO2 concentrations on the metabolic rate (oxygen consumption) and the development of ocellated wrasse early life stages, we ran two field experiments, collecting embryos from nesting sites with different partial pressures of CO2 [pCO2; ambient (~400 μatm) and high (800-1000 μatm)] and reciprocally transplanting embryos from ambient- to high-CO2 sites for 30 h. Ocellated wrasse offspring brooded in different CO2 conditions had similar responses, but after transplanting portions of nests to the high-CO2 site, embryos from parents that spawned in ambient conditions had higher metabolic rates. Although metabolic phenotypic plasticity may show a positive response to high CO2, it often comes at a cost, in this case as a smaller size at hatching. This can have adverse effects because smaller larvae often exhibit a lower survival in the wild. However, the adverse effects of increased CO2 on metabolism and development did not occur when embryos from the high-CO2 nesting site were exposed to ambient conditions, suggesting that offspring from the high-CO2 nesting site could be resilient to a wider range of pCO2 values than those belonging to the site with present-day pCO2 levels. Our study identifies a crucial need to increase the number of studies dealing with these processes under global change trajectories and to expand these to naturally high-CO2 environments, in order to assess further the adaptive plasticity mechanism that encompasses nongenetic inheritance (epigenetics) through parental exposure and other downstream consequences, such as survival of larvae

    Effects of recreational scuba diving on Mediterranean fishes: evidence of involuntary feeding?

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    Despite a large body of literature assessing the impacts of recreational scuba diving on marine habitats, little attention has been paid to the potentially harmful effects this has on fishes. The aim of this study was the assessment of the immediate response of different fish species to divers’ activities. A decrease of fishes’ natural diffidence towards divers is shown, probably due to an enhanced availability of their prey as a result of divers’ contacts with the substrate

    A scoring system for biliary atresia: Is this the right one?

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    A clinical diagnostic score for biliary atresia in discusse

    RESULTS OF DIFFERENT ANTHROPIC USES ON THE STRUCTURE OF VERMETID REEFS

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    The biogenic vermetid reef is a key habitat of coastal ecosystems that modifies the shoreline morphology and increases the local biodiversity. Despite its ecological relevance, rarely it is subjected to an accurate management and is often exposed to several human activities. This study aims to distinguish between the effects of different typologies of anthropic uses on the physical structure of the vermetid reef. A comparison between totally protected, partially protected and strongly anthropized reefs has been done and two variables have been analysed: the substratum complexity and the density of reef-building organism. Both the variables show higher values in totally and partially protected reefs, demonstrating the importance of conservation strategies for the correct management of this important bioconstruction

    GLI EFFETTI DEL DISTURBO ANTROPICO SULLA TOPOGRAFIA DEL REEF A VERMETI

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    Intertidal vermetid reefs could be affected by many human disturbances. Using a microtopography device, the authors analysed the changes induced by the accessibility on the surface topography of the reefs. Human activities seems to be able to induce a decrease in rugosity and a surface smoothing on the outer margin of the reef. These effects are proportional to the accessibility of the site

    DISTRIBUTION AND CONSERVATION NEEDS OF A NEGLECTED ECOSYSTEM: THE MEDITERRANEAN VERMETID REEF

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    Vermetid reefs are a key intertidal habitat in the Mediterranean. Despite recent evidence of local extinction in the Eastern Mediterranean, their role as habitat engineers and the high numbers of ecosystem services they provide, vermetid reefs are among the least known marine habitats of the Mediterranean. Here we present a literature-based study to assess for the first time their distribution inside the basin and provide evidence of a general lack of protection at Mediterranean scale

    Evaluation of skin temperature change as stress indicator in rabbit through infrared thermography

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    AbstractStress-induced reactions in animals include behavioural and physiological modifications aiming at coping towards the stressor, such as manipulations. Thermography, that is the detection of ..

    A Coupled VEM-BEM Approach for Computational Homogenization of Heterogeneous Materials

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    The Boundary Element Method (BEM) is well established as an accurate and powerful numerical technique in continuum mechanics. Due to its intrinsic feature of reducing the problem's dimensionality, which allows reducing the modelling effort without compromising on the solution accuracy, the BEM has been successfully employed for the computational homogenization of materials with complex morphologies. The Virtual Element Method (VEM) has recently emerged as a powerful and robust technique, capable of handling very general polygonal/polyhedral mesh elements. Such a property is of interest in treating problems whose analysis domain presents complex geometric features, as it simplifies the data preparation stage of the analysis. In this work, we use a coupled VEM-BEM approach for computational homogenization of heterogeneous materials whose microstructure is characterized by inclusions of irregular shapes embedded in a surrounding matrix
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