4 resultados para P-Body

em Publishing Network for Geoscientific


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Behavioural field observations are increasingly being used in ecotoxicological research to identify potential adverse effects of exposure to persistent organic pollutants (POPs). We investigated thermal conditions inside the nest and parental behaviour of glaucous gulls, Larus hyperboreus, breeding in the Norwegian Arctic in relation to the concentrations of major classes of POPs (organochlorines, brominated flame retardants and metabolically derived products) accumulated in their blood. Most notably, nest temperature was negatively correlated with the concentrations of the sum of DDT, sum of PCB and several quantitatively minor POP classes within the incubating parent. To investigate the relationship between incubation ability and parental POP exposure further, we experimentally increased the costs of incubation by artificially increasing the clutch size from two to four eggs. Clutch enlargement was followed by a decrease in nest temperature, but this drop in temperature was not associated with POP concentrations within the incubating parent. However, males, which had higher POP concentrations and lower white blood cell counts than females, seemed less able to maintain nest temperature. There was virtually no evidence to suggest that the sum of PCB or DDT were associated with changes in the time a bird spent incubating. However, there was some indication that nest site attendance by nonincubating males was negatively related to the sum of DDT, suggesting that nest protection may have been compromised. The results suggest that adverse effects of parental POP exposure may occur through suboptimal thermal conditions for embryo development and possibly increased egg predation risk.

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Objectives: The International Polar Year (IPY) Inuit Health Survey provided an opportunity to compare dietary and body mass index (BMI) data with data collected a decade earlier for the same communities. Study design: A dietary survey included 1,929 randomly selected participants aged 15 years or older, selected from 18 Inuit communities in 1998-1999. The IPY survey included 2,595 randomly selected participants aged 18 years or older, selected from 36 Inuit communities in 2007-2008. Data from the same 18 communities included in both surveys were compared for adults 20 years and older. Methods: Twenty-four-hour dietary recall data were analysed to assess the percentage of energy from traditional and market foods by sex and age groups. Body mass index (BMI) was assessed to establish the prevalence of obesity by sex and age groups in both surveys. Results: There was a significant decrease (p<=0.05) in energy contribution from traditional food and a significant increase in market food consumption over time. Sugar-sweetened beverages, chips and pasta all increased as percentages of energy. BMI increased overall for women and for each age stratum evaluated (p<0.05). Conclusion: The nutrition transition continues in the Canadian Arctic with a concurrent increase in BMI.

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We report on wintertime data collected from Baffin Bay and northern Davis Strait, a major gateway linking the Arctic with the subpolar North Atlantic, using narwhals (Monodon monoceros) as an oceanographic sampling platform. Fourteen narwhals were instrumented with satellite-linked time-depth-temperature recorders between 2005 and 2007. Transmitters collected and transmitted water column temperature profiles from each dive between December and April, where >90% of maximum daily dive depths reached the bottom. Temperature measurements were combined with 15 helicopter-based conductivity-temperature-depth (CTD) casts taken in April 2007 across central Baffin Bay and compared with hydrographic climatology values used for the region in Arctic climate models. Winter temperature maxima for whale and CTD data were in good agreement, ranging between 4.0°C and 4.6°C in inshore and offshore Baffin Bay and in Davis Strait. The warm Irminger Water was identified between 57°W and 59°W (at 68°N) between 200 and 400 m depths. Whale data correlated well with climatological temperature maxima; however, they were on average 0.9°C warmer ±0.6°C (P < 0.001). Furthermore, climatology data overestimated the winter surface isothermal layer thickness by 50-80 m. Our results suggest the previously documented warming in Baffin Bay has continued through 2007 and is associated with a warmer West Greenland Current in both of its constituent water masses. This research demonstrates the feasibility of using narwhals as ocean observation platforms in inaccessible Arctic areas where dense sea ice prevents regular oceanographic measurements and where innate site fidelity, affinity for winter pack ice, and multiple daily dives to >1700 m offer a useful opportunity to sample the area.