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101.
This report describes the necropsy findings in 3 cats with a natural T-lymphotropic Lentivirus (FTLV) infection. The changes are compared with the "immunodeficiency syndrome" of humans and monkeys. Furthermore, the pathogenicity of the FTLV and the significance of a dual infection with FTLV and Spumavirus is discussed. 相似文献
102.
Glucose concentrations after insulin‐induced hypoglycemia and glycemic variability in healthy and diabetic cats 下载免费PDF全文
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E. Rohmeder v. Pechmann Mägdefrau A. Bernhart J. L. Lutz 《European Journal of Forest Research》1961,80(11-12):393-396
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Bouman HA Ulloa O Scanlan DJ Zwirglmaier K Li WK Platt T Stuart V Barlow R Leth O Clementson L Lutz V Fukasawa M Watanabe S Sathyendranath S 《Science (New York, N.Y.)》2006,312(5775):918-921
By using data collected during a continuous circumnavigation of the Southern Hemisphere, we observed clear patterns in the population-genetic structure of Prochlorococcus, the most abundant photosynthetic organism on Earth, between and within the three Southern Subtropical Gyres. The same mechanisms that were previously invoked to account for the vertical distribution of ecotypes at local scales accounted for the global (horizontal) patterns we observed. Basin-scale and seasonal variations in the structure and strength of vertical stratification provide a basis for understanding large-scale horizontal distribution in genetic and physiological traits of Prochlorococcus, and perhaps of marine microbial communities in general. 相似文献
108.
Toxic potential of materials at the nanolevel 总被引:12,自引:0,他引:12
Nanomaterials are engineered structures with at least one dimension of 100 nanometers or less. These materials are increasingly being used for commercial purposes such as fillers, opacifiers, catalysts, semiconductors, cosmetics, microelectronics, and drug carriers. Materials in this size range may approach the length scale at which some specific physical or chemical interactions with their environment can occur. As a result, their properties differ substantially from those bulk materials of the same composition, allowing them to perform exceptional feats of conductivity, reactivity, and optical sensitivity. Possible undesirable results of these capabilities are harmful interactions with biological systems and the environment, with the potential to generate toxicity. The establishment of principles and test procedures to ensure safe manufacture and use of nanomaterials in the marketplace is urgently required and achievable. 相似文献
109.
Steen Magnussen Lutz Fehrman William J. Platt 《European Journal of Forest Research》2012,131(2):307-320
Density estimators for k-tree distance sampling are sensitive to the amount of extra Poisson variance in distances to the kth tree. To lessen this sensitivity, we propose an adaptive composite estimator (COM). In simulated sampling from 16 test
populations, a three-component composite density estimator (COM)–with weights determined by a multinomial logistic function
of four readily available ancillary variables–was identified as superior in terms of average relative absolute bias. Results
from a different set of nine validation populations–with widely different stem densities and spatial patterns of tree locations—confirmed
that relative root mean squared errors (RRMSE) of COM were, on average, considerably lower than those obtained with the three-component
k-tree density estimators. The RRMSE performance of COM improved with increasing values of k. With k = 6 and sample sizes of 10, 20, and 30, the average relative bias of COM was between −5 and 5% in seven validation populations
but in an open low-density savanna-like population bias reached −12% (1979 data) and 7% (1996 data). For k = 6 and n = 10, the RRMSE of COM was, in six of the nine validation populations, within 3.3 percentage points of the RRMSE for sampling
with fixed-area plots. Jackknife estimates of the precision of COM estimates of density were negatively biased, leading to
under-coverage (7%) of computed 95% confidence intervals. 相似文献
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