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11.
Synthesis of Acetylcholine in the Absence of Exogenous Choline 总被引:3,自引:0,他引:3
THE breakdown of acetyl-CoA during incubation with rat brain homogenate or sections of rat nervous tissue in the absence of choline has been reported by Kasa, Mann and Hebb1. They found that the conversion of 14C-acetyl-CoA to 14C-acetate thus incubated was considerably depressed by 10?4 eserine or 10?5 M di-isopropylfluorophosphate (DFP) but further depressed by 10?3 M DFP. Experiments in our laboratories lead us to offer an explanation for that part of the breakdown inhibited by eserine or low concentrations of DFP. 相似文献
12.
C-Type Virus associated with Gibbon Lymphosarcoma 总被引:49,自引:0,他引:49
THOMAS G. KAWAKAMI SALLY D. HUFF PATRICIA M. BUCKLEY DONALD L. DUNGWORTH STANLEY P. SNYDER RAYMOND V. GILDEN 《Nature: New biology》1972,235(58):170-171
C-TYPE viruses have been established as the causal agents of leukaemia in murine and feline species and have been characterized1,2. C-type virus is also probably associated with fibrosarcoma in non-human primates3–6. To determine whether viruses with identical characteristics are associated with other neoplasms in simian species, we looked for C-type viruses in cases of leukaemia. A gibbon (Hylobates lar) with a disseminated tumour (later confirmed as lymphosarcoma) was made available to the Comparative Oncology Laboratory by Dr Malcolm Jones of the University of California, San Francisco Medical Center. The principal sites of involvement (lymph node, liver and bone marrow) were extensively overrun with massive neoplastic cells, which were predominantly prolymphocytic forms. Electron microscopy revealed C-type particles identical to those observed in vitro in sections from lymph nodes, liver, spleen and bone marrow. 相似文献
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R. BUCKLEY 《Austral ecology》1981,6(4):405-422
This is the third of a series of papers describing the soils and vegetation of the central Australian sandridges and their interrelations. It details topographic—floristic patterns on fourteen transects at seven sites in the northwest, southwest and southeast Simpson Desert. There is a consistent vegetational zonation on the main Simpson sandridges, with regional modifications due to the broad scale NW-SE floristic gradient. Closer dunes have more similar vegetation than distant ones. Swale vegetation is less consistent than sandridge vegetation and depends on soil type. Species differ greatly in their degree of restriction both topographically and geographically. Zone separation differs greatly between dunes in consequence. Zones defined on overall floristics are less clearly separated in the Simpson than in the western deserts. A floristically and structurally distinct crest zone is recognizable on all main dunefield sandridges. The only universally applicable zonation is swale, flank, crest. Vegetation patterns are more closely correlated with field soil texture than with topography. 相似文献
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LISETTE P. WAITS VALERIE A. BUCKLEY‐BEASON WARREN E. JOHNSON DAVE ONORATO TOM MCCARTHY 《Molecular ecology resources》2007,7(2):311-314
Snow leopards (Panthera uncia) are elusive endangered carnivores found in remote mountain regions of Central Asia. New methods for identifying and counting snow leopards are needed for conservation and management efforts. To develop molecular genetic tools for individual identification of hair and faecal samples, we screened 50 microsatellite loci developed for the domestic cat (Felis catus) in 19 captive snow leopards. Forty‐eight loci were polymorphic with numbers of alleles per locus ranging from two to 11. The probability of observing matching genotypes for unrelated individuals (2.1 × 10?11) and siblings (7.5 × 10?5) using the 10 most polymorphic loci was low, suggesting that this panel would easily discriminate among individuals in the wild. 相似文献
16.
Scotch broom (Cytisus scoparius) is a serious weed of natural and pastoral ecosystems and is invasive in many countries worldwide. Eight polymorphic microsatellite loci were developed and characterized for this species. The number of alleles per locus ranged from five to 23. The range of observed heterozygosity was between 0.207 and 0.928. These microsatellite markers will be useful tools for studies of population genetics in the native and invasive range of this species. 相似文献
17.
Evolutionary radiation of the cicada genus Maoricicada Dugdale (Hemiptera: Cicadoidea) and the origins of the New Zealand alpine biota 总被引:2,自引:0,他引:2
THOMAS R. BUCKLEY CHRIS SIMON 《Biological journal of the Linnean Society. Linnean Society of London》2007,91(3):419-435
We have used ancestral character state reconstruction and molecular dating to test hypotheses on the evolution of New Zealand alpine cicadas of the genus Maoricicada Dugdale. Gene trees were estimated from mitochondrial DNA and the nuclear loci elongation factor 1-α, period, and calmodulin and species-level relationships were reconstructed using gene tree parsimony. These analyses suggest that the alpine habitat character state had a single origin and that the ancestral Maoricicada lived in low to mid-elevation habitats. Our reconstructions also strongly support the hypothesis that this ancestor was darkly coloured and had increased pubescence, classic adaptations of alpine insects. Using relaxed-clock Bayesian dating methods, we estimated that the radiation of the alpine Maoricicada species was coincident with the late Miocene acceleration in the rate of uplift of the Southern Alps rather than uplift in the early Miocene. These dates are very similar to those of other alpine taxa, indicating that the New Zealand alpine biota is very young. Our reconstructions suggest that the ancestral Maoricicada may have been preadapted to the alpine environment because it existed before the origin of high mountainous habitats, dwelt at mid-to-low altitudes, and yet possessed the classic alpine insect adaptations of heavy pubescence and dark coloration. © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 91 , 419–435. 相似文献
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Fluorescent antibody and complement-fixation tests of agents isolated in tissue culture from measles patients 总被引:4,自引:0,他引:4
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