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排序方式: 共有171条查询结果,搜索用时 78 毫秒
71.
Smart ME Cymbaluk NF Christensen DA 《The Canadian veterinary journal. La revue veterinaire canadienne》1992,33(3):163-170
Primary and secondary copper deficiency has been identified in most Canadian provinces. Research has been done investigating the environmental and dietary factors that influence dietary copper availability and the effect of deficient copper status on the health and production of cattle. Across Canada, a high percentage of forages and grains are marginal to deficient in copper. In certain regions, high sulphates in the water and/or high molybdenum concentrations in the feed decrease dietary copper availability. The value of various oral and parenteral copper supplements in the treatment and prevention of copper deficiency is discussed. 相似文献
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Dewhirst SY Birkett MA Loza-Reyes E Martin JL Pye BJ Smart LE Hardie J Pickett JA 《Pest management science》2012,68(10):1419-1429
BACKGROUND: Two important pests of the sweet pepper, Capsicum annuum, are the peach potato aphid, Myzus persicae, and the glasshouse potato aphid, Aulacorthum solani. Current aphid control measures include the use of biological control agents, i.e. parasitic wasps, but with varying levels of success. One option to increase parasitoid efficiency is to activate plant defence. Therefore, sweet pepper plants were treated with the naturally occurring plant defence activator cis-jasmone, and its impact upon the behaviour and development of aphids and aphid parasitoids was investigated. RESULTS: Growth rate studies revealed that the intrinsic rate of population increase of A. solani and M. persicae on sweet pepper plants treated with cis-jasmone (cJSP) was not affected compared with untreated plants (UnSP), but the positive behavioural response of alate M. persicae towards the volatile organic compounds (VOCs) from UnSP was eliminated by cis-jasmone treatment 48 h previously (cJSP48). In addition, the aphid parasitoid Aphidius ervi preferred VOCs from cJSP48 compared with UnSP, and a significant increase in foraging time was also observed on cJSP. Analysis of VOCs collected from cJSP48 revealed differences compared with UnSP. CONCLUSION: There is evidence that treatment with cis-jasmone has the potential to improve protection of sweet pepper against insect pests. © Crown copyright 2012. Reproduced with permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd. 相似文献
75.
Harriette C. Schapiro James H. Mathewson James F. Steenbergen Scott Kellogg Camella Ingram Gregory Nierengarten Harvey Rabin 《Aquaculture (Amsterdam, Netherlands)》1974,3(4):403-408
Infection (gaffkemia) can be induced in the California spiny lobster (P. interruptus) with injections of Pediococcus homari (formerly Gaffkya homari). An LD5 0 of 103 microbes per ml hemolymph is observed at 17°C. Prior immunization of lobsters (P. interruptus) with an avirulent strain of P. homari protects lobsters against 100 × LD5 0. This is the first report of acquired immunity to P. homari in a susceptible species. The high incidence of gaffkemia in American lobsters (Homarus americanus) held in live holding facilities makes prophylactic measures essential in regions outside the enzootic area of the North Atlantic to avoid inadvertent transplantation of the disease to other susceptible populations of animals. 相似文献
76.
Harvey RJ Depner UB Wässle H Ahmadi S Heindl C Reinold H Smart TG Harvey K Schütz B Abo-Salem OM Zimmer A Poisbeau P Welzl H Wolfer DP Betz H Zeilhofer HU Müller U 《Science (New York, N.Y.)》2004,304(5672):884-887
Prostaglandin E2 (PGE2) is a crucial mediator of inflammatory pain sensitization. Here, we demonstrate that inhibition of a specific glycine receptor subtype (GlyR alpha3) by PGE2-induced receptor phosphorylation underlies central inflammatory pain sensitization. We show that GlyR alpha3 is distinctly expressed in superficial layers of the spinal cord dorsal horn. Mice deficient in GlyR alpha3 not only lack the inhibition of glycinergic neurotransmission by PGE2 seen in wild-type mice but also show a reduction in pain sensitization induced by spinal PGE2 injection or peripheral inflammation. Thus, GlyR alpha3 may provide a previously unrecognized molecular target in pain therapy. 相似文献
77.
Beck JW Richards DA Edwards RL Silverman BW Smart PL Donahue DJ Hererra-Osterheld S Burr GS Calsoyas L Jull AJ Biddulph D 《Science (New York, N.Y.)》2001,292(5526):2453-2458
A long record of atmospheric 14C concentration, from 45 to 11 thousand years ago (ka), was obtained from a stalagmite with thermal-ionization mass-spectrometric 230Th and accelerator mass-spectrometric 14C measurements. This record reveals highly elevated Delta14C between 45 and 33 ka, portions of which may correlate with peaks in cosmogenic 36Cl and 10Be isotopes observed in polar ice cores. Superimposed on this broad peak of Delta14C are several rapid excursions, the largest of which occurs between 44.3 and 43.3 ka. Between 26 and 11 ka, atmospheric Delta14C decreased from approximately 700 to approximately 100 per mil, modulated by numerous minor excursions. Carbon cycle models suggest that the major features of this record cannot be produced with solar or terrestrial magnetic field modulation alone but also require substantial fluctuations in the carbon cycle. 相似文献
78.
Clathrin light chains LCA and LCB are similar, polymorphic, and share repeated heptad motifs 总被引:19,自引:0,他引:19
T Kirchhausen P Scarmato S C Harrison J J Monroe E P Chow R J Mattaliano K L Ramachandran J E Smart A H Ahn J Brosius 《Science (New York, N.Y.)》1987,236(4799):320-324
The clathrin light chains fall into two major classes, LCA and LCB. In an intact clathrin triskelion, one light chain, of either class, is bound to the proximal segment of a heavy chain leg. Analysis of rat brain and liver complementary DNA clones for LCA and LCB shows that the two light chain classes are closely related. There appear to be several members of each class having deletions of varying length aligned at the same position. A set of ten heptad elements, characteristic of alpha-helical coiled coils, is a striking feature of the central part of each derived amino acid sequence. These observations suggest a model in which the alpha-helical segment mediates binding to clathrin heavy chains and the amino- and carboxyl-terminal segments mediate interactions with other proteins. They also suggest an explanation for the observed tissue-dependent size variation for members of each class. 相似文献
79.
CASE HISTORY: A 7-year-old cat developed sporadic vomiting, reduced appetite, and weight loss over the previous 3 months.CLINICAL FINDINGS: Palpation revealed a large mid-abdominal mass and the cat had marked eosinophilia. The cat progressively lost weight over the next 7 weeks when euthanasia was performed.PATHOLOGICAL FINDINGS: Necropsy revealed a 3?cm diameter firm white intramural mass in the colon and another in the pylorus. Mesenteric and cranial mediastinal lymph nodes were firm, pale, and enlarged. Histopathological examination revealed foci of necrosis surrounded by thick dense collagen trabeculae and predominantly eosinophilic inflammation within the intestine and lymph nodes. Marked eosinophilic infiltration of the liver was also present.DIAGNOSIS: The lesions were consistent with gastrointestinal eosinophilic sclerosing fibroplasia (FGESF).CLINICAL RELEVANCE: This is the first report of FGESF in a New Zealand cat and the first time lesions of FGESF have been observed in extra-abdominal tissues. Intestinal neoplasia can be clinically identical to FGESF and histopathology is required for differentiation. Evidence suggests that FGESF has a more favourable prognosis than intestinal neoplasia. 相似文献
80.
Kendall Vande Kamp Matthew Rigge Nels H. Troelstrup Alexander J. Smart Bruce Wylie 《Strength and Conditioning Journal》2013,66(1):63-70
Heavily grazed riparian areas are commonly subject to channel incision, a lower water table, and reduced vegetation, resulting in sediment delivery above normal regimes. Riparian and in-channel vegetation functions as a roughness element and dissipates flow energy, maintaining stable channel geometry. Ash Creek, a tributary of the Bad River in western South Dakota contains a high proportion of incised channels, remnants of historically high grazing pressure. Best management practices (BMP), including off-stream watering sources and cross fencing, were implemented throughout the Bad River watershed during an Environmental Protection Agency (EPA) 319 effort to address high sediment loads. We monitored prairie cordgrass (Spartina pectinata Link) establishment within stream channels for 16 yr following BMP implementation. Photos were used to group stream reaches (n=103) subjectively into three classes; absent (estimated <5% cover; n=64), present (estimated 5–40% cover; n=23), and dense (estimated >40% cover; n=16) based on the relative amount of prairie cordgrass during 2010 assessments of ephemeral channels. Reaches containing drainage areas of 0.54 to 692 ha were delineated with the use of 2010 National Agriculture Imagery Program (NAIP) imagery. Normalized difference vegetation index (NDVI) values were extracted from 5 to 39 sample points proportional to reach length using a series of Satellite Pour l’Observation de la Terre (SPOT) satellite imagery. Normalized NDVI (nNDVI) of 2152 sample points were determined from pre- and post-BMP images. Mean nNDVI values for each reach ranged from 0.33 to 1.77. ANOVA revealed significant increase in nNDVI in locations classified as present prairie cordgrass cover following BMP implementation. Establishment of prairie cordgrass following BMP implementation was successfully detected remotely. Riparian vegetation such as prairie cordgrass adds channel roughness that reduces the flow energy responsible for channel degradation. 相似文献