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Sheppard PR Speakman RJ Ridenour G Witten ML 《Environmental monitoring and assessment》2007,130(1-3):511-518
This paper describes the use of lichen chemistry to assess airborne tungsten and cobalt in Fallon, Nevada, where a cluster
of childhood leukemia has been on going since 1997. Lichens and their rock substrates were collected from Rattlesnake Hill
within Fallon as well as from four different rock outcrops located north, east, south, and west of Fallon and at least 20 km
away from the town center. In the lichens themselves, W and Co are significantly higher within Fallon than in the combined
control site outside of Fallon. In the rock substrates of the lichens, no differences exist in W and Co. The W and Co differences
in lichens cannot be attributed to substrate geochemistry. Fallon is distinctive in west central Nevada for high airborne
W and Co, and given its cluster of childhood leukemia, it stands to reason that additional biomedical research is in order
to test directly the leukogenicity of combined airborne W and Co. 相似文献
2.
Many endotherms save energy during food and water shortage or unpredictable environment using controlled reductions in body
temperature and metabolism called torpor. In this study, we measured energy metabolism and water turnover in free-ranging
grey mouse lemurs Microcebus murinus (approximately 60 g) using doubly labelled water during the austral winter in the rain forest of southeastern Madagascar.
We then compared patterns of thermal biology between grey mouse lemurs from the rain forest and a population from the dry
forest. M. murinus from the rain forest, without a distinct dry season, entered daily torpor independent of ambient temperature (T
a). There were no differences in torpor occurrence, duration and depth between M. murinus from the rain and dry forest. Mouse lemurs using daily torpor reduced their energy expenditure by 11% in the rain forest
and by 10.5% in the dry forest, respectively. There was no significant difference in the mean water flux rates of mouse lemurs
remaining normothermic between populations of both sites. In contrast, mean water flux rate of individuals from the dry forest
that used torpor was significantly lower than those from the rain forest. This study represents the first account of energy
expenditure, water flux and skin temperature (T
sk) in free-ranging M. murinus from the rain forest. Our comparative findings suggest that water turnover and therefore water requirement during the austral
winter months plays a more restricting role on grey mouse lemurs from the dry forest than on those from the rain forest. 相似文献
3.
Sheppard PR Speakman RJ Ridenour G Glascock MD Farris C Witten ML 《Environmental geochemistry and health》2007,29(5):405-412
Spatial patterns of tungsten and cobalt are described for surface dust of Fallon, Nevada, where a cluster of childhood leukemia
has been ongoing since 1997. In earlier research, airborne tungsten and cobalt was shown to be elevated in total suspended
particulates in Fallon. To fine-tune the spatial patterns of tungsten and cobalt deposition in Fallon, surface dust was collected
in a grid pattern within as well as outside of Fallon to establish background concentrations of metals. In surface dust, tungsten
and cobalt show sharp peaks (934 ppm and 98 ppm, respectively) within Fallon just north of highway 50 and west of highway
95. These two peaks overlap spatially, and given the grid pattern used for collecting surface dust, the source area of these
two airborne metals can be pinpointed to the vicinity of hard-metal industry located north of highway 50 and west of highway
95. Fallon is distinctive in west central Nevada because of high airborne tungsten and cobalt particulates, and given its
cluster of childhood leukemia, it stands to reason that additional biomedical research is in order to test directly the leukogenicity
of combined airborne tungsten and cobalt particulates. 相似文献
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Marked interindividual variation in metabolic rate suggests considerable complexity in energy management strategies, but attempts to further our understanding of the relationship between resting metabolic rate (RMR), daily energy expenditure (DEE), and reproductive effort have been hampered by the complexity of studying this system in the field. Here, we describe energy management strategies in a captive-breeding system, using Zebra Finches (Taeniopygia guttata), to demonstrate the high level of complexity and interindividual variability in energy expenditure, food intake, locomotor activity, and reproductive effort. In particular, we investigated whether the increase in RMR associated with egg production is additive, resulting in higher DEE and a need for elevated food intake, or whether this cost is compensated by reduced expenditure in nonreproductive components of the energy budget. We found high levels of intra-individual variation in energy expenditure associated with egg production in female Zebra Finches, e.g., comparing nonbreeding stage with the one-egg stage, change in RMR varied from 4.0% and 41.3%, and change in DEE varied from -33.3% to +46.4%. This variation was systematically related to aspects of locomotor activity and reproductive effort. Females with the largest increase in RMR during egg production decreased locomotor activity the most but still had increased DEE at the one-egg stage, and females with high DEE at the one-egg stage produced larger clutches. Our study suggests that females minimize increases in DEE during egg production through behavioral energy reallocation (reduced locomotor activity) but that individuals differ in their use of this strategy, which, in turn, is related to the absolute level of reproductive investment. This suggests a very complex, individually variable system of energy management to meet the demands of egg production. 相似文献
6.
Feathers as a means of monitoring mercury in seabirds: Insights from stable isotope analysis 总被引:7,自引:0,他引:7
Thompson DR Bearhop S Speakman JR Furness RW 《Environmental pollution (Barking, Essex : 1987)》1998,101(2):193-200
Mercury concentrations, together with nitrogen and carbon stable isotope signatures, were determined in body feather samples from northern fulmars Fulmarus glacialis and great skuas Catharacta skua, and in different flight feathers from great skuas. There were no significant relationships between trophic status, as defined using isotope analysis, and mercury concentration in the same feather type, in either species. Mercury concentrations in body feather samples were markedly different between fulmars and skuas, reflecting differences in diet, but there was no corresponding difference in trophic status as measured through nitrogen stable isotope signatures. We conclude that mercury concentrations and stable isotope values in feathers are uncoupled, mercury concentrations apparently reflecting the body pool of accumulated mercury at the time of feather growth whilst stable isotope values reflect the diet at the time of feather growth. There were significant positive correlations between the different flight feathers of great skuas for all three parameters measured. These were strongest between primary 10 and secondary 8, suggesting that these two feathers are replaced at the same time in the moult sequence in great skuas. Stable isotope analysis of different feathers may provide a means of investigating moult patterns in birds. 相似文献
7.
Lori H. Schwacke Tiago A. Marques Len Thomas Cormac G. Booth Brian C. Balmer Ashley Barratclough Kathleen Colegrove Sylvain De Guise Lance P. Garrison Forrest M. Gomez Jeanine S. Morey Keith D. Mullin Brian M. Quigley Patricia E. Rosel Teresa K. Rowles Ryan Takeshita Forrest I. Townsend Todd R. Speakman Randall S. Wells Eric S. Zolman Cynthia R. Smith 《Conservation biology》2022,36(4):e13878
The 2010 Deepwater Horizon (DWH) oil spill exposed common bottlenose dolphins (Tursiops truncatus) in Barataria Bay, Louisiana to heavy oiling that caused increased mortality and chronic disease and impaired reproduction in surviving dolphins. We conducted photographic surveys and veterinary assessments in the decade following the spill. We assigned a prognostic score (good, fair, guarded, poor, or grave) for each dolphin to provide a single integrated indicator of overall health, and we examined temporal trends in prognostic scores. We used expert elicitation to quantify the implications of trends for the proportion of the dolphins that would recover within their lifetime. We integrated expert elicitation, along with other new information, in a population dynamics model to predict the effects of observed health trends on demography. We compared the resulting population trajectory with that predicted under baseline (no spill) conditions. Disease conditions persisted and have recently worsened in dolphins that were presumably exposed to DWH oil: 78% of those assessed in 2018 had a guarded, poor, or grave prognosis. Dolphins born after the spill were in better health. We estimated that the population declined by 45% (95% CI 14–74) relative to baseline and will take 35 years (95% CI 18–67) to recover to 95% of baseline numbers. The sum of annual differences between baseline and injured population sizes (i.e., the lost cetacean years) was 30,993 (95% CI 6607–94,148). The population is currently at a minimum point in its recovery trajectory and is vulnerable to emerging threats, including planned ecosystem restoration efforts that are likely to be detrimental to the dolphins’ survival. Our modeling framework demonstrates an approach for integrating different sources and types of data, highlights the utility of expert elicitation for indeterminable input parameters, and emphasizes the importance of considering and monitoring long-term health of long-lived species subject to environmental disasters. Article impact statement: Oil spills can have long-term consequences for the health of long-lived species; thus, effective restoration and monitoring are needed. 相似文献
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