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11.
12.
E F Hill 《Journal of wildlife diseases》1988,24(1):51-61
Organophosphorus and carbamate pesticides are potent anticholinesterase substances that have killed large numbers of wild birds of various species. Cause of death is diagnosed by demonstration of depressed brain cholinesterase (ChE) activity in combination with chemical detection of anticholinesterase residue in the affected specimen. ChE depression is determined by comparison of the affected specimen to normal ChE activity for a sample of control specimens of the same species, but timely procurement of controls is not always possible. Therefore, a reference file of normal whole brain ChE activity is provided for 48 species of wild birds from North America representing 11 orders and 23 families for use as emergency substitutes in diagnosis of anticholinesterase poisoning. The ChE values, based on 83 sets of wild control specimens from across the United States, are reproducible provided the described procedures are duplicated. Overall, whole brain ChE activity varied nearly three-fold among the 48 species represented, but it was usually similar for closely related species. However, some species were statistically separable in most families and some species of the same genus differed as much as 50%. 相似文献
13.
Two acrasid cellular slime molds. Guttulinopsis vulgaris and G. nivea, are compared at the ultrastructural level. The amoebae of the two species are indistinguishable except for the presence of intranuclear fibers in G. vulgaris. Both species share some unusual features, including: plate-like cristae in the mitochondria, production of microbody-like organelles in the perinuclear space, spores with thin bilaminar walls, and stalks containing microfilaments bound in striated bundles. These and other observations are discussed with regard to the development of the sorocarps and the relationship of the genus to other members of the Acrasida. 相似文献
14.
Published gene frequency data, checked for consistency of allele definitions across laboratories and for comparability of
geographically identical samples, were pooled into a data set containing frequencies at nine loci for each of 20 populations
that encompassed 10 macaque species. Genetic distances were calculated by the methods of Kidd and Cavalli-Sforza (1974). These
distances were used to construct phylogenetic trees and to evaluate the relationships between divergence times and effective
population sizes. Inter-and intraspecific genetic distances and the groupings defined by phenetic tree analyses support Fooden’s
(1976) classification of the genus Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows
us to explain Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows
us to explain qualitatively the inferred evolutionary relationships among macaque species. Many assumptions are required in
order to estimate the variables necessary in the quantitative prediction of genetic differences for a comparison between any
two populations. Examination of those assumptions demonstrates the need for more accurate genetic as well as paleozoogeographic
information.
An erratum to this article is available at . 相似文献
15.
John A. Schneider Rakhi Dandona Shravani Pasupneti Vemu Lakshmi Chuanhong Liao Vijay Yeldandi Kenneth H. Mayer 《PloS one》2010,5(7)
Studies of HIV prevention interventions such as pre-exposure prophylaxis (PREP) and circumcision in India are limited. The present study sought to investigate Indian truck-drivers initial commitment to PREP and circumcision utilizing the AIDS Risk Reduction Model. Ninety truck-drivers completed an in-depth qualitative interview and provided a blood sample for HIV and HSV-2 testing. Truck-drivers exhibited low levels of initial commitment towards PREP and even lower for circumcision. However, potential leverage points for increasing commitment were realized in fear of infecting family rather than self, self-perceptions of risk, and for PREP focusing on cultural beliefs towards medication and physicians. Cost was a major barrier to both HIV prevention interventions. Despite these barriers, our findings suggest that the ARRM may be useful in identifying several leverage points that may be used by peers, health care providers and public health field workers to enhance initial commitment to novel HIV prevention interventions in India. 相似文献
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Catherine E. Rogers Karl R. Mattox Kenneth D. Stewart 《American journal of botany》1980,67(5):774-783
Chlorokybus atmophyticus has a sarcinoid growth habit and produces scale-covered zoospores. Flagella are laterally inserted and attached internally to a multilayered structure characteristic of the Charophyceae. There are two kinds of pyrenoid in each cell, a feature previously observed in only one scaly green flagellate. C. atmophyticus demonstrates that the sarcinoid growth habit arose independently at least twice in the green algae and cannot be used to define taxonomic groups unless combined with other criteria. It is further concluded that C. atmophyticus should be classified in a separate family Chlorokybaceae and a separate order Chloroky bales. 相似文献