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排序方式: 共有391条查询结果,搜索用时 31 毫秒
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212.
Levy JK Edinboro CH Glotfelty CS Dingman PA West AL Kirkland-Cady KD 《Journal of the American Veterinary Medical Association》2007,231(2):218-225
OBJECTIVE: To determine seroprevalence of dirofilariasis in dogs and seroprevalences of dirofilariasis, FeLV infection, and FIV infection in cats exported from the Gulf Coast region following the 2005 hurricanes. DESIGN: Seroprevalence survey. ANIMALS: 1,958 dogs and 1,289 cats exported from Louisiana, Mississippi, and Texas between August 20 and December 31, 2005. PROCEDURES: 141 animal welfare groups in 37 states and Alberta, Canada, reported results of serologic testing. Risk factors for infection, including age, sex, neuter status, breed, and state of rescue, were examined by means of univariate and multivariate logistic regression. RESULTS: Seroprevalence of dirofilariasis in dogs was 48.8%. Sexually intact dogs were 1.6 times as likely to have dirofilariasis as were neutered dogs, dogs in the ancient breed group were 2.2 times as likely and dogs in the guarding breed group were 1.7 times as likely to have dirofilariasis as were dogs in the herding breed group, and dogs from Mississippi were significantly less likely to have dirofilariasis than were dogs from Texas. Seroprevalences of dirofilariasis, FeLV infection, and FIV infection in cats were 4.0%, 2.6%, and 3.6%, respectively. Seroprevalence of FIV infection was significantly higher in adult cats than in juveniles and in males than in females. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dogs and cats exported from the 2005 Gulf Coast hurricane disaster area had disease rates similar to those for animals in the region prior to the hurricanes. 相似文献
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Sander J. Zwart Wim G.M. Bastiaanssen Charlotte de Fraiture 《Agricultural Water Management》2010,97(10):1628-1408
Water productivity in agriculture needs to be improved significantly in the coming decades to secure food supply to a growing world population. To assess on a global scale where water productivity can be improved and what the causes are for not reaching its potential, the current levels must be understood. This paper describes the development and validation of a WATer PROductivity (WATPRO) model for wheat that is based on remote sensing-derived input data sets, and that can be applied at local to global scales. The model is a combination of Monteith's theoretical framework for dry matter production in plants and an energy balance model to assess actual evapotranspiration. It is shown that by combining both approaches, the evaporative fraction and the atmospheric transmissivity, two parameters which are usually difficult to estimate spatially, can be omitted. Water productivity can then be assessed from four spatial variables: broadband surface albedo, the vegetation index NDVI, the extraterrestrial radiation and air temperature. A sensitivity analysis revealed that WATPRO is most sensitive to changes in NDVI and least sensitive to changes in air temperature. The WATPRO model was applied at 39 locations where water productivity was measured under experimental conditions. The correlation between measured and modelled water productivity was low, and this can be mainly attributed to differences in scales and in the experimental and modelling periods. A comparison with measurements from farmer's fields in areas surrounded by other wheat fields located in Sirsa District, NW India, showed an improved correlation. Although not a validation, a comparison with SEBAL-derived water productivity in the same region in India proved that WATPRO can spatially predict water productivity with the same spatial variation. 相似文献
215.
Hexose oxidase (EC 1.1.3.5) (HOX) was purified 51-fold from the red algae Chondrus crispus, by several chromatography methods, including hydrophobic interaction, chelating Sepharose, anion exchange, gel filtration, and chromatofocusing. Purified HOX was subjected to native PAGE and activity staining with nitroblue tetrazolium. For HOX electroeluted out of the gel and digested with endoproteinase Lys-C, the internal peptide sequence determined was: D-P-G-Y-I-V-I-D-V-N-A-G-T-(V or P)-D-K-P-D-P-X. The molecular mass, determined by gel filtration, was 126 kDa, versus 65 kDa determined by SDS-PAGE. The pI was determined to 4.64 and 4.79 as a double band on an isoelectrofocusing gel. Km was determined to 2.7 mM for D-glucose, 3.6 mM for D-galactose, 20.2 mM for cellobiose, 43.7 mM for maltose, 90.3 mM for lactose, 102 mM for xylose, and 531 mM for arabinose. The oxidation of thiol groups in gluten was determined by using Ellman's reagent: 5,5′-dithiobis (2-nitrobenzoic acid). The effect of HOX was compared to that of glucose oxidase. Both enzymes caused a dose-responsive reduction in the free thiol groups. Extensigraph measurements and baking tests confirmed that HOX caused increased dough strength and increased bread volume more efficiently than glucose oxidase used in the same dosage. 相似文献
216.
Marie Cooper Ragnar L. Olsen Jørgen Seliussen Charlotte Gannefors 《Journal of the World Aquaculture Society》2011,42(2):222-229
Chronic over‐exposure to diet‐borne copper has been implicated in the development of black stripes caused by melanin deposits (melanosis) around the blood vessels in fillets of farmed Atlantic cod, Gadus morhua L. To test this hypothesis a 6‐mo pilot study using feeds containing controlled amounts of copper has been performed. Cumulative data from each feed group showed that 56% of cod fed a diet containing 10 mg/kg of added copper had black stripe while 58% of cod on a diet containing 5 mg/kg of added copper were affected. Cod on a diet with no added copper had 33% of individuals positive for black stripe, and in a final group on a diet containing no supplementary trace metals and minerals 16% of individuals were affected. Weight gain, increase in length, hepatosomatic index, and condition factor were unaffected by the changes made to mineral supplements. Melanosis has been observed in 24% wild cod of market size (n = 30) whilst 85% of market‐sized farmed cod examined have had black stripe (n = 403). 相似文献
217.
Charlotte Hecht-Buchholz 《植物养料与土壤学杂志》1998,161(5):509-520
Recent attention has been drawn to plant-growth-promoting bacteria which colonize not only the rhizosphere and the surface of roots but also the interior of roots and shoots of higher plants. The bacteria are found in the apoplast i.e. intercellular spaces and xylem vessels. These so-called endophytic bacteria are considered to be more effective in providing the host plant with nitrogen than associative rhizosphere bacteria on the root surface and appear to play an important role in biological nitrogen fixation (BNF) in nonleguminous plants. This is discussed in detail. Bacteria which have been found in the apoplast of nonleguminous plants include Azospirillum spp., Pantoea agglomerans, Acetobacter diazotrophicus, Herbaspirillum spp., Azoarcus spp. and Rhizobium spp. The significance of the apoplastic colonization of these bacteria for the nitrogen nutrition of tropical non-legumes is discussed. 相似文献
218.
Ali Jafarpour Simon Gregersen Rocio Marciel Gomes Paolo Marcatili Tobias Hegelund Olsen Charlotte Jacobsen Michael Toft Overgaard Ann-Dorit Moltke Srensen 《Marine drugs》2020,18(12)
Protein hydrolysates show great promise as bioactive food and feed ingredients and for valorization of side-streams from e.g., the fish processing industry. We present a novel approach for hydrolysate characterization that utilizes proteomics data for calculation of weighted mean peptide properties (length, molecular weight, and charge) and peptide-level abundance estimation. Using a novel bioinformatic approach for subsequent prediction of biofunctional properties of identified peptides, we are able to provide an unprecedented, in-depth characterization. The study further characterizes bulk emulsifying, foaming, and in vitro antioxidative properties of enzymatic hydrolysates derived from cod frame by application of Alcalase and Neutrase, individually and sequentially, as well as the influence of heat pre-treatment. All hydrolysates displayed comparable or higher emulsifying activity and stability than sodium caseinate. Heat-treatment significantly increased stability but showed a negative effect on the activity and degree of hydrolysis. Lower degrees of hydrolysis resulted in significantly higher chelating activity, while the opposite was observed for radical scavenging activity. Combining peptide abundance with bioinformatic prediction, we identified several peptides that are likely linked to the observed differences in bulk emulsifying properties. The study highlights the prospects of applying proteomics and bioinformatics for hydrolysate characterization and in food protein science. 相似文献
219.
Landscape Ecology - Collisions with wind turbines threaten bat populations worldwide. Previous studies tried to assess the effects of landscape on mortalities. Yet, the count of carcasses found per... 相似文献
220.
Remko A. Griep Charlotte van Twisk Arjen Schots 《European journal of plant pathology / European Foundation for Plant Pathology》1999,105(2):147-156
Methods for the generation of monoclonal antibodies against plant viruses are limited because current hybridoma techniques do not allow efficient exploitation of the immune repertoire. Moreover, the immunization procedures often lead to a bias towards an immunodominant contaminant in the immunogen preparation and not to the plant virus itself. The selection of six different single-chain antibody variable fragments (scFv) against beet necrotic yellow vein virus from a semi-synthetic human combinatorial antibody library showed the feasibility of the phage display system. No bias towards minor contaminants in the purified virus preparation was observed in ELISA, as all the selected scFvs reacted only with beet necrotic yellow vein virus infected plant homogenates. In addition, two of the isolated beet necrotic yellow vein virus-specific scFvs could be produced in E. coli as a scFv fusion protein with alkaline phosphatase, and were applied in ELISA as specific ready to use antibody-enzyme conjugates. Because of their specificity, these antibodies have potential to be used as reagents in sensitive diagnostic assays for routine testing for beet necrotic yellow vein virus in sugar beets. 相似文献