The influence of trophic level as measured by δ15N on mercury concentrations in freshwater organisms     

K. A. Kidd  R. H. Hesslein  R. J. P. Fudge  K. A. Hallard 《Water, air, and soil pollution》1995,80(1-4):1011-1015

The relationship between mercury (Hg) concentrations in freshwater biota and trophic position, as defined by stable nitrogen isotope ratios (δ¹⁵N), was examined in 6 lakes in northwestern Ontario. The heavier isotope of nitrogen (¹⁵N) increases an average of 3 parts per thousand (‰) from prey to predator and is used as a measure of an organism's trophic position. Dorsal muscle from lake trout, burbot, walleye, northern pike, white sucker, lake cisco, lake whitefish, and yellow perch was analyzed for Hg and δ¹⁵N using flameless atomic absorption and mass spectrometry respectively. Within each lake, log Hg was significantly related to δ¹⁵N (r ² ranged from 0.47 to 0.91,P<0.01). For four species, yellow perch, northern pike, lake cisco, and lake trout, log Hg was positively related to δ¹⁵N (r ² ranged from 0.37 to 0.47,P≤0.09) across all lakes. We also used δ¹⁵N measurements (assuming a 3‰ shift between an organism and its diet) and the developed within-lake regression equations to calculate a prey Hg for each individual fish. These food Hg values were then used to predict predator Hg using Norstromet al's bioenergetics model. Predicted results were strongly correlated to measured Hg concentrations (r=0.91,P<0.001), indicating that δ¹⁵N has potential to be used in modeling.  相似文献   

Epidemiology. DNA identifications after the 9/11 World Trade Center attack     

Biesecker LG  Bailey-Wilson JE  Ballantyne J  Baum H  Bieber FR  Brenner C  Budowle B  Butler JM  Carmody G  Conneally PM  Duceman B  Eisenberg A  Forman L  Kidd KK  Leclair B  Niezgoda S  Parsons TJ  Pugh E  Shaler R  Sherry ST  Sozer A  Walsh A 《Science (New York, N.Y.)》2005,310(5751):1122-1123

The attack on the World Trade Center on 9/11/2001 challenged current approaches to forensic DNA typing methods. The large number of victims and the extreme thermal and physical conditions of the site necessitated special approaches to the DNA-based identification. Because of these and many additional challenges, new procedures were created or modified from routine forensic protocols. This effort facilitated the identification of 1594 of the 2749 victims. In this Policy Forum, the authors, who were were members of the World Trade Center Kinship and Data Analysis Panel, review the lessons of the attack response from the perspective of DNA forensic identification and suggest policies and procedures for future mass disasters or large-scale terrorist attacks.  相似文献   

The foot and ankle of Australopithecus sediba     

Zipfel B  DeSilva JM  Kidd RS  Carlson KJ  Churchill SE  Berger LR 《Science (New York, N.Y.)》2011,333(6048):1417-1420

A well-preserved and articulated partial foot and ankle of Australopithecus sediba, including an associated complete adult distal tibia, talus, and calcaneus, have been discovered at the Malapa site, South Africa, and reported in direct association with the female paratype Malapa Hominin 2. These fossils reveal a mosaic of primitive and derived features that are distinct from those seen in other hominins. The ankle (talocrural) joint is mostly humanlike in form and inferred function, and there is some evidence for a humanlike arch and Achilles tendon. However, Au. sediba is apelike in possessing a more gracile calcaneal body and a more robust medial malleolus than expected. These observations suggest, if present models of foot function are correct, that Au. sediba may have practiced a unique form of bipedalism and some degree of arboreality. Given the combination of features in the Au. sediba foot, as well as comparisons between Au. sediba and older hominins, homoplasy is implied in the acquisition of bipedal adaptations in the hominin foot.  相似文献   

High concentrations of toxaphene in fishes from a subarctic lake     

Kidd KA  Schindler DW  Muir DC  Lockhart WL  Hesslein RH 《Science (New York, N.Y.)》1995,269(5221):240-242

Concentrations of toxaphene and other organochlorine compounds are high in fishes from subarctic Lake Laberge, Yukon Territory, Canada. Nitrogen isotope analyses of food chains and contaminant analyses of biota, water, and dated lake sediments show that the high concentrations of toxaphene in fishes from Laberge resulted entirely from the biomagnification of atmospheric inputs. A combination of low inputs of toxaphene from the atmosphere and transfer through an exceptionally long food chain has resulted in concentrations of toxaphene in fishes that are considered hazardous to human health.  相似文献   

Interactions of the branched-chain amino acids. 2. Practical adjustments in valine and isoleucine     

C.W. Maynard  G.J. Mullenix  C.J. Maynard  J.T. Lee  S.K. Rao  L.D. Butler  S.K. Orlowski  M.T. Kidd 《The Journal of Applied Poultry Research》2022,31(2):100241

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