31 research outputs found

    Noise and Vibration Levels in Artificial Polar Bear Dens as Related to Selected Petroleum Exploration and Developmental Activities

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    The noise and vibration levels resulting from seismic testing, drilling and transport were measured in artificial polar bear dens of Prudhoe Bay, Alaska. It was concluded that the dry and wind-beaten arctic snow muffles both sound and vibrations extremely well and it seems unlikely that polar bears in their dens will be disturbed by the type of petroleum-related activities measured here, providing those activities do not take place within 100 m of the den.Key words: Ursus marifimus, seismic activity, conservationRÉSUMÉ. Dans des tanières artificielles d'ours polaires situées Prudhoe Bay en Alaska, on a mesuré le niveau de vibrations et de bruit dus aux essais sismiques, au forage et au transport. On en conclut que la neige sêche de l'Arctique, durcie par le vent, atténue trbs bien sons et vibrations, eitl semble peu probable que les ours polaires soient dérangés dans leurs tanibres par les activité pétrolières qui ont fait l'objet de nos mesures, pourvu que ces activités n'aient pas lieu à moins de 100 m de la tanière.Mots clés: Ursus marifimus, activité sismique, préservatio

    Metabolic rate and plasma T3 in ad lib. fed and starved muskoxen

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    Resting metabolic rate (RMR) in two 12 yrs., semidomesticated, female muskoxen was 0.86 ± 0.10 W • kg-1 in winter, and 1.74 ± 0.27 W • kg-1 in summer, (p<0.001). After 6 days of starvation RMR was down to 0.62 + 0.07 W • kg-1 and 0.77 ± 0.03 W • kg-1 (p<0.001) in winter and summer, respectively. RMR during starvation in winter was 19% below predicted RMR for animals of equal body mass. Standing RMR was significantly higher (p<0.01) than lying RMR. Winter plasma levels of T3 in both animals were 1-1 nmol • l-1 when food was freely available, and 1.4 nmol • l-1 after 6 days of starvation. Plasma concentration of T3 in another 8 free ranging semi-domesticated, female muskoxen aged 12 yrs. in March was 0.64 ± 0.20 nmol • l-1. Corrseponding value in August was 1.00 ± 0.10 nmol • l-1, being significantly higher (p<0.01) than the winter value

    A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean

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    The development of models of marine ecosystems in the Southern Ocean is becoming increasingly important as a means of understanding and managing impacts such as exploitation and climate change. Collating data from disparate sources, and understanding biases or uncertainties inherent in those data, are important first steps for improving ecosystem models. This review focuses on seals that breed in ice habitats of the Southern Ocean (i.e. crabeater seal, Lobodon carcinophaga; Ross seal, Ommatophoca rossii; leopard seal, Hydrurga leptonyx; and Weddell seal, Leptonychotes weddellii). Data on populations (abundance and trends in abundance), distribution and habitat use (movement, key habitat and environmental features) and foraging (diet) are summarised, and potential biases and uncertainties inherent in those data are identified and discussed. Spatial and temporal gaps in knowledge of the populations, habitats and diet of each species are also identified

    Why Rudolph's nose is red: Observational study

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    Objective: To characterise the functional morphology of the nasal microcirculation in humans in comparison with reindeer as a means of testing the hypothesis that the luminous red nose of Rudolph, one of the most well known reindeer pulling Santa Claus's sleigh, is due to the presence of a highly dense and rich nasal microcirculation. Design: Observational study. Setting: Tromsø, Norway (near the North Pole), and Amsterdam, the Netherlands. Participants: Five healthy human volunteers, two adult reindeer, and a patient with grade 3 nasal polyposis. Main outcome measures: Architecture of the microvasculature of the nasal septal mucosa and head of the inferior turbinates, kinetics of red blood cells, and real time reactivity of the microcirculation to topical medicines. Results: Similarities between human and reindeer nasal microcirculation were uncovered. Hairpin-like capillaries in the reindeers' nasal septal mucosa were rich in red blood cells, with a perfused vessel density of 20 (SD 0.7) mm/mm2. Scattered crypt or gland-like structures surrounded by capillaries containing flowing red blood cells were found in human and reindeer noses. In a healthy volunteer, nasal microvascular reactivity was demonstrated by the application of a local anaesthetic with vasoconstrictor activity, which resulted in direct cessation of capillary blood flow. Abnormal microvasculature was observed in the patient with nasal polyposis. Conclusions: The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25% higher than that in humans. These results highlight the intrinsic physiological properties of Rudolph's legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer's brain, factors essential for flying reindeer pulling Santa Claus's sleigh under extreme temperatures

    Antarctic pack-ice seal research, February and March 1995

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    As upper trophic level predators with a circumpolar distribution, the antarctic pack ice seals (crabeater, Lobodon carcinophagus; leopard, Hydrurga leptonyx; Ross, Ommatophoca rossii; and Weddell, Leptonychotes weddelli) provide a potential source of information about ecosystem interactions and environmental variability integrated over a wide range of spatial and temporal scales. In recent years, increasing attention has been focused on the need to conduct antarctic pack-ice seal research, and a multifaceted international research initiative to address priority pack-ice seal research topics is being developed: the Antarctic Pack Ice Seals (APIS) Program

    Análise das recomendações internacionais sobre o consumo de açúcares publicadas entre 1961 e 1991

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    Realizou-se levantamento das recomendações nutricionais sobre o consumo de açúcares contidas nas publicações especializadas em todo o mundo, nos últimos 30 anos. Objetivou-se investigar as recomendações sobre o consumo de açúcares e identificar qual orientação deveria ser dada ao público e autoridades competentes sobre os níveis ideais de açúcares na dieta compatíveis com uma boa saúde. As informações foram obtidas de 116 publicações elaboradas por comitês de especialistas de 37 diferentes países e regiões do mundo, incluindo principalmente países desenvolvidos, mas também aqueles em desenvolvimento. Os resultados permitiram concluir que a grande maioria (84,5% das publicações analisadas) fazem recomendações sobre o consumo de açúcares extrínsecos ou livres, havendo consenso de que estes açúcares, principalmente a sacarose, devem ser reduzidos da dieta. A recomendação mais freqüente é 10% de calorias a partir dos açúcares extrínsecos como um nível máximo. Tais recomendações são geralmente dirigidas à toda a população com a finalidade de manter a saúde geral, mas sobretudo prevenir a cárie dental e a obesidade. Concluiu-se que as recomendações sobre o consumo de açúcares contidas nas publicações editadas nas últimas três décadas são coerentes com a evidência científica da relação entre os açúcares e as doenças crônicas e, portanto, deveriam ser integradas às políticas de alimentação e saúde
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