131,084 research outputs found

    Life in a warm deep sea: routine activity and burst swimming performance of the shrimp Acanthephyra eximia in the abyssal Mediterranean

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    Measurements of routine swimming speed, "tail-flip'' escape responses, and oxygen consumptions were made of the deep-sea shrimp Acanthephyra eximia using autonomous landers in the Rhodos Basin at depths of up to 4,400 m and temperatures of 13 - 14.5 degrees C. Routine swimming speeds at 4,200 m averaged 0.18 m s(-1) or 3.09 body lengths s(-1), approximately double those of functionally similar oceanic scavengers. During escape responses peak accelerations of 23 m s(-2) or 630.6 body lengths s(-2) were recorded, with animals reaching speeds of 1.61 m s(-1) or 34.8 body lengths s(-2). When compared to shallow-water decapods at similar temperatures these values are low for a lightly calcified shrimp such as A. eximia despite a maximum muscle mass specific power output of 90.0 W kg(-1). A preliminary oxygen consumption measurement indicated similar rates to those of oceanic crustacean scavengers and shallower-living Mediterranean crustaceans once size and temperature had been taken into account. These animals appear to have high routine swimming speeds but low burst muscle performances. This suite of traits can be accounted for by high competition for limited resources in the eastern Mediterranean, but low selective pressure for burst swimming due to reductions in predator pressure

    Predicting global habitat suitability for stony corals on seamounts

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    Aim Globally, species distribution patterns in the deep sea are poorly resolved, with spatial coverage being sparse for most taxa and true absence data missing. Increasing human impacts on deep-sea ecosystems mean that reaching a better understanding of such patterns is becoming more urgent. Cold-water stony corals (Order Scleractinia) form structurally complex habitats (dense thickets or reefs) that can support a diversity of other associated fauna. Despite their widely accepted ecological importance, records of scleractinian corals on seamounts are patchy and simply not available for most of the global ocean. The objective of this paper is to model the global distribution of suitable habitat for stony corals on seamounts. Location Seamounts worldwide. Methods We compiled a database containing all accessible records of scleractinian corals on seamounts. Two modelling approaches developed for presence-only data were used to predict global habitat suitability for seamount scleractinians: maximum entropy modelling (Maxent) and environmental niche factor analysis (ENFA). We generated habitat-suitability maps and used a cross-validation process with a threshold-independent metric to evaluate the performance of the models. Results Both models performed well in cross-validation, although the Maxent method consistently outperformed ENFA. Highly suitable habitat for seamount stony corals was predicted to occur at most modelled depths in the North Atlantic, and in a circumglobal strip in the Southern Hemisphere between 20° and 50° S and shallower than around 1500 m. Seamount summits in most other regions appeared much less likely to provide suitable habitat, except for small near-surface patches. The patterns of habitat suitability largely reflect current biogeographical knowledge. Environmental variables positively associated with high predicted habitat suitability included the aragonite saturation state, and oxygen saturation and concentration. By contrast, low levels of dissolved inorganic carbon, nitrate, phosphate and silicate were associated with high predicted suitability. High correlation among variables made assessing individual drivers difficult. Main conclusions Our models predict environmental conditions likely to play a role in determining large-scale scleractinian coral distributions on seamounts, and provide a baseline scenario on a global scale. These results present a first-order hypothesis that can be tested by further sampling. Given the high vulnerability of cold-water corals to human impacts, such predictions are crucial tools in developing worldwide conservation and management strategies for seamount ecosystems. © 2009 Blackwell Publishing Ltd

    The current status of dental education and the dental profession in Chile

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    Indexación: Scopus.Objective: To describe the current situation of the dental profession in Chile, including training and workforce issues. Material and Methods: Data were collected from different national institutions, which included information regarding number of current registered dentists, university of graduation, geographical distribution, professional position, additional specialty certifications obtained, the number and characteristics of dental surgeons who work in the public and private sectors, the traditional character of the university, the accreditation status of the undergraduate dental programs and the general population number. Results: Currently there are 32 schools of Dentistry in Chile, of which 21 have their quality certified. There are 19,100 Chilean dentists and 1,727 foreign dentists registered. The number of graduates from private universities has increased significantly. Currently, 2,164 dentists work for MINSAL. Less than a third hold a specialty certification. Forty-five percent of the dental specialists obtained their certification from universities. The current professional ratio is 104 dentists per 100,000 habitants. Conclusion: The number of dentists in Chile has increased progressively during the last years, mainly associated with the opening of new dental schools. Only 28% of the Chilean dental schools have certified their quality for the total duration of the undergraduate program. Regarding the workforce, there is a public/private and geographical inequities in dentists’ distribution.http://revista.uepb.edu.br/index.php/pboci/article/view/3875/pd

    More control and better access in 2025?

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    From: Tommy Cartes

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    Not just a new face

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    Aperçu des études menées par la section québécoise de l’Inventaire des terres du Canada

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    C'est au cours de la conférence « les ressources et notre avenir » tenue en octobre 1961, que les gouvernements fédéral et provinciaux ont entrepris de procéder à l'inventaire des ressources renouvelables au Canada.Des méthodes de travail basées sur les caractères biophysiques ont été mises au point dès 1964 afin d'obtenir des systèmes de classement uniformes pour tout le Canada, dans les secteurs de l'agriculture, de la forêt, de la récréation, de la faune ongulée et de la faune sauvagine. En septembre 1969, la section québécoise de l'Inventaire des Terres du Canada publie un document intitulé « Les systèmes de classement des possibilités d'utilisation des sols », suivi, en juin 1971, de « La méthodologie du zonage des terres selon leurs potentiels », ouvrage élaboré à partir des cartes originales de potentiel. En mai 1972, paraît une carte d'analyse des terres de la région de l'Outaouais (sud-ouest du Québec) qu'accompagne un rapport d'analyse de la région, considérée comme région pilote.La section québécoise de l'I.T.C. possède maintenant 3 257 cartes dont 662 cartes d'utilisation du sol, 440 cartes agricoles, 407 cartes forestières, 649 cartes de la récréation, 298 cartes de la faune ongulée, 550 cartes de la faune sauvagine et 251 cartes de zonage
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