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91.
The spread of the genus Lactuca worldwide includes 16 species in Europe, 51 in Asia, 43 in Africa and 12 in America (mostly North American subcontinent). Natural distributions of Lactuca spp. are compared with the representation of wild Lactuca spp. in world genebank collections as recently summarized in the International Lactuca database (ILDB). A total of 27 wild Lactuca species are reported in world genebank collections in the ILDB, however, due to incorrect taxonomic determination the real number of species is lower. The substantial part (92%) of the collections is represented only by three species (L. serriola, L. saligna, L. virosa) and from a geographic viewpoint they are mostly European in origin. The autochthonous species originating from other continents (Asia, Africa, America), which form c. 83% of known Lactuca spp. richness, are very poorly represented in collections (only c. 3%). The majority of accessions originate from Europe (59%) and Asia (37%), nevertheless the whole area of natural distribution is not well covered. An extremely low number of accessions is available from Africa and America (2% each). Thus, the global biodiversity of Lactuca spp. germplasm is represented very poorly and is biased in genebank collections. For future studies of taxonomy, phytogeography, ecology, phylogenetic relationships, genetic diversity, inter- and intra-population structure, resistance research and practical breeding exploitation of wild Lactuca spp. germplasm, plant material from a wider ecogeographic distribution must be collected and introduced into genebank collections more intensively. 相似文献
92.
Boner PL Liu DD Feely WF Robinson RA Wu J 《Journal of agricultural and food chemistry》2003,51(26):7555-7559
An accurate, reliable, and reproducible assay was developed and validated to determine flunixin in bovine liver, kidney, muscle, and fat. The overall recovery and percent coefficient of variation (%CV) of twenty-eight determinations in each tissue for flunixin free acid were 85.9% (5.9% CV) for liver, 94.6% (9.9% CV) for kidney, 87.4% (4.7% CV) for muscle, and 87.6% (4.4% CV) for fat. The theoretical limit of detection was 0.1 microg/kg (ppb, ng/g) for liver and kidney, and 0.2 ppb for muscle and fat. The theoretical limit of quantitation was 0.3, 0.2, 0.6, and 0.4 ppb for liver, kidney, muscle, and fat, respectively. The validated lower limit of quantitation was 1 ppb for edible tissues with the upper limit of 400 ppb for liver and kidney, 100 ppb for fat, and 40 ppb for muscle. Accuracy, precision, linearity, specificity, ruggedness, and storage stability were demonstrated. Briefly, the method involves an initial acid hydrolysis, followed by pH adjustment ( approximately 9.5) and partitioning with ethyl acetate. A portion of the ethyl acetate extract was purified by solid-phase extraction using a strong cation exchange cartridge. The eluate was then evaporated to dryness, reconstituted, and analyzed using LC/MS/MS. The validated method is sensitive and specific for flunixin in edible bovine tissue. 相似文献
93.
Seaman Dave J. I. Voigt Maria Bocedi Greta Travis Justin M. J. Palmer Stephen C. F. Ancrenaz Marc Wich Serge Meijaard Erik Bernard Henry Deere Nicolas J. Humle Tatyana Struebig Matthew J. 《Landscape Ecology》2021,36(10):2957-2975
Landscape Ecology - Agricultural expansion is a leading cause of deforestation and habitat fragmentation globally. Policies that support biodiversity and facilitate species movement across farmland... 相似文献
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Twelve tanks of juvenile rainbow trout, Oncorhynchus mykiss (Walbaum), were treated twice weekly for an 11- week period with a one-hour static bath of chloramine-T (10 mg l–1 ). The morphometric indices of gill damage and the histochemical characteristics of gill mucous cells of fish from treated and paired untreated tanks were compared. The use pattern of chloramine-T in this study evoked a slight increase in mean lamellar width, but it did not induce a greater degree of lamellar oedema, lamellar fusion, tissue infiltration, epithelial hyperplasia, chloride cell metaplasia or thrombosis of pillar channels in treated fish. Treatment caused a trend towards an increased number of mucous cells on lamellae, associated with a significant shift from neutral mucin to acid mucin production based on histochemical characteristics. 相似文献
96.
Antioxidant activity in common beans (Phaseolus vulgaris L.) 总被引:4,自引:0,他引:4
Cardador-Martínez A Loarca-Piña G Oomah BD 《Journal of agricultural and food chemistry》2002,50(24):6975-6980
Beans were pearled to evaluate the feasibility of increasing antioxidant activity and phenolic antioxidants. Phenolics were concentrated mostly in the hull fraction at about 56 mg of catechin equivalents per gram of sample. The methanolic extracts of the pearled bean samples were screened for antioxidant potential using the beta-carotene-linoleate and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) in vitro model systems. The pearled material, also referred to as milled samples, exhibited antioxidant activity that correlated with phenolic content and inhibited DPPH significantly in a dose-dependent manner. Phenolics and antioxidant activities were also examined in chromatographic fractions of methanolic extracts of manually obtained hulls that represented a model used previously to ascertain antimutagenic activity. Fractions extracted with ethyl acetate/acetone and acetone displayed antioxidant activity, which implies potent free radical scavenging activity with antimutagenic activity. 相似文献
97.
98.
Jabier. Ruiz-Mirazo Greg J. Bishop-Hurley Dave L. Swain 《Strength and Conditioning Journal》2011,64(3):240-248
Grazing livestock freely select landscape resources, unless they are herded or constrained by fences. Automated animal control (AAC) systems offer an alternative to physical fences by using animal-positioning technology and aversive stimuli to deter animals from staying in sensitive environments and so limit their impact. This paper reports on a replicated field experiment completed to test whether occasional stimuli (audio cue followed by a mild electric stimulus), delivered by discontinuously activated AAC collars, could suffice to modify the grazing behavior of groups of cattle. Four groups of eight steers were confined in 8-ha rectangular paddocks that had an ad libitum supplement feeder located in one end to attract cattle. The steers' positional information was recorded continuously for 3 d using a GPS receiver encased in a collar fitted around their neck. These data were used to characterize their use of the paddocks without intervention. Subsequently a restriction zone was activated on the collars. This zone contained the supplement feeders and represented approximately 10% of the paddock area. Cattle movement was again monitored during a second 3-d period, in which the steers were subjected to discontinuous aversive stimuli (5 min of stimulation followed by a random 0–30 min interval without stimulation) if they were located inside or moved into the restriction zone. Cattle visits to the restriction zone were shorter and the return interval longer when steers were subjected to discontinuous stimulation. Overall, there was a 97% reduction in the use of the restriction zone between the first and second deployments. These results suggest that grazing impact can be drastically reduced by making a zone less desirable through discontinuous aversive stimulation. Such a discontinuous (25% of the time on) AAC system can reduce power consumption in collars and so help overcome energy supply limitations that hinder commercial AAC applications. 相似文献
99.
100.