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941.
The world's domestic cats carry patterns of sequence variation in their genome that reflect a history of domestication and breed development. A genetic assessment of 979 domestic cats and their wild progenitors-Felis silvestris silvestris (European wildcat), F. s. lybica (Near Eastern wildcat), F. s. ornata (central Asian wildcat), F. s. cafra (southern African wildcat), and F. s. bieti (Chinese desert cat)-indicated that each wild group represents a distinctive subspecies of Felis silvestris. Further analysis revealed that cats were domesticated in the Near East, probably coincident with agricultural village development in the Fertile Crescent. Domestic cats derive from at least five founders from across this region, whose descendants were transported across the world by human assistance.  相似文献   
942.
The 4 different disposal techniques that are used in California for industrial waste disposal are discussed. These are: Treatment (usually chemical) followed by solar evaporation of the liquid from ponds; Incineration; Biodegradation; and Land disposal - usually burial or injection into soil or solid waste (garbage).  相似文献   
943.
944.
945.
Bacteriophages, herpesviruses, and other large double-stranded DNA (dsDNA) viruses contain molecular machines that pump DNA into preassembled procapsids, generating internal capsid pressures exceeding, by 10-fold, that of bottled champagne. A 17 angstrom resolution asymmetric reconstruction of the infectious P22 virion reveals that tightly spooled DNA about the portal dodecamer forces a conformation that is significantly different from that observed in isolated portals assembled from ectopically expressed protein. We propose that the tight dsDNA spooling activates the switch that signals the headful chromosome packing density to the particle exterior.  相似文献   
946.
Ethylene was tested as a sprout inhibitor on potatoes intended for processing over the 2006-2007 and the 2007-2008 storage seasons. Russet Burbank, Shepody, Innovator, FL-1867, and FL-1833 were loaded into the University of Maine potato research facility in October of 2006. Ethylene gas was metered into the storage until a concentration of 0.1 ppm was reached and then held for one week. At weekly intervals, the ethylene concentration was increased to 0.3 ppm, 0.6 ppm, 12 ppm, 5.0 ppm and 102 ppm. Subsequently, the concentration was maintained at 10.0 ppm for the duration of the storage season. Control potatoes received chlorpropham (CIPC) for sprout control. The trial was repeated in the 2007-2008 storage season. The Agtron readings were performed on the processed potatoes at the end of the storage season. There was no difference in the US color grade between the CIPC-treated and ethylene-treated tubers within any tested variety in either storage season. Sprout inhibition of the ethylene-treated potatoes was acceptable for normal storage length of the potato varieties tested. Ethylene may have promise as an alternate to CIPC for sprout control in potato storages.  相似文献   
947.
How the widely used botulinum neurotoxin A (BoNT/A) recognizes and enters neurons is poorly understood. We found that BoNT/A enters neurons by binding to the synaptic vesicle protein SV2 (isoforms A, B, and C). Fragments of SV2 that harbor the toxin interaction domain inhibited BoNT/A from binding to neurons. BoNT/A binding to SV2A and SV2B knockout hippocampal neurons was abolished and was restored by expressing SV2A, SV2B, or SV2C. Reduction of SV2 expression in PC12 and Neuro-2a cells also inhibited entry of BoNT/A, which could be restored by expressing SV2 isoforms. Finally, mice that lacked an SV2 isoform (SV2B) displayed reduced sensitivity to BoNT/A. Thus, SV2 acts as the protein receptor for BoNT/A.  相似文献   
948.
Cuphea (Cuphea viscosissima Jacq. x C. lanceolata W.T. Aiton, PSR23) is a new oilseed being developed in the north-central USA. Cuphea oil is high in medium-chain fatty acids suitable for detergent/cleaner applications and has potential for use in cosmetics. The objectives of this study were to determine the effect of seed development on seed moisture, weight, oil content, fatty acid composition, germination, and vigor. Two thousand cuphea flowers were tagged at anthesis in the field each year at Prosper, ND, in 2004, 2005, and 2006. Each flower that developed into a seed capsule was tagged and labeled with the date of anthesis. Two hundred developed capsules from the labeled flowers were harvested at 3 to 4-day intervals from 5- to 35 days post anthesis corresponding with 37 to 295 growing degree days (GDD). The GDD were calculated using a base temperature of 10 °C. Seed development required approximately 253 GDD or 30 days post anthesis to reach physiological maturity. Maximum seed germination was reached at 33 days post anthesis. Seed oil content increased and oil composition changed as seed matured. Seed oil was high in linoleic and palmitic acids from 0 to 10 days post anthesis and declined thereafter while capric acid began to accumulate at 10 days post anthesis and reached above 70% at physiological maturity.  相似文献   
949.
A set of descriptors for evaluating guayule germplasm   总被引:1,自引:0,他引:1  
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950.
Soil salinity disturbs the equilibrium between reactive oxygen species (ROS) production and removal, leading to a dramatic increase in ROS concentration and oxidative damage. Enzymatic scavenging is one of the two main mechanisms involved in ROS detoxification in plants. This study has investigated the role of major antioxidant (AO) enzymes in mitigating salinity‐induced oxidative stress in plant shoots. Firstly, two barley varieties were used to evaluate the activity of major AO enzymes in different leaves and at different times after salt treatment. Our results showed that AO enzyme activities had strong tissue and time specificity. A further study was conducted using six barley varieties contrasting in salinity tolerance. AO enzyme activities and proline contents were measured in the third leaves of seedlings after plants were treated with 240 mm NaCl for 10 days. No significant correlation was revealed between leaf AO activity and either plant grain yield or plant survival rate under salt stress. In contrast, a significant increase in leaf proline content under salt stress was found in all sensitive varieties, while in most tolerant varieties, salt stress did not change leaf proline level. It is concluded that although salinity induces changes in leaf AO enzyme activities, the changes cannot be used as biochemical indicators in breeding for salinity tolerance.  相似文献   
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