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931.
M. Hühn 《Plant Breeding》1992,109(1):28-34
In many fields of application in plant breeding and crop science, ratios of two component traits X and Y are of interest (harvest index in cereals, leaf-to-stem ratio in forage legumes, height-to-diameter ratio in forest trees etc.). When selection is practised on the ratio X/Y of two traits X and Y, the experimenter may be interested in the resulting changes of both trait means. Based on improved approximations for the covariances between X and X/Y and between Y and X/Y and for the variance of X/Y the changes in the means of X and Y can be predicted by applying the regression approach from conventional selection theory. Explicit expressions for these correlated responses in X and Y when selection is practised on their ratio X/Y are derived and discussed. The different outcomes (decrease, zero change or increase) for the selection pressures on X and Y are characterized by phenotypic coefficients of variation of X and Y, phenotypic and genotypic correlations between X and Y and heritabilities of X and Y. 相似文献
932.
L C Savon M Alonso J Rodriguez-Diego T Blandino 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1992,45(1):30-31
The attenuation of a Babesia bovis strain depends on its protease content. The present work evaluates this parameter on a virulent strain, before and after attenuation by quick passages on splenectomized calves. The protease activity at different pH values was determined in protein fractions from the blood of calves. The enzymatic test showed marked differences between the protease content of both substrains. 相似文献
933.
Michael S. Stone Ian B. Johnstone Marjory Brooks Trent K. Bollinger Susan M. Cotter 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(1):57-61
A circulating anticoagulant was detected in a 2-year-old Chesapeake Bay Retriever with hemolytic anemia, nephrotic syndrome, thrombocytopenia, polyarthropathy, and pulmonary thromboembolism. A persistent prolongation of the activated partial thromboplastin time (aPTT) was detected, and it did not correct with repeated administration of fresh frozen plasma. The aPTT was still prolonged, with a 1:1 mixture of patient's plasma and normal dog plasma in vitro, suggesting the presence of a circulating inhibitor. Results of assays to characterize the inhibitor were compatible with those described for the lupus anticoagulant in human patients with systemic lupus erythematosus. Paradoxically, patients having the lupus anticoagulant are at increased risk for thrombosis. Pulmonary thromboembolism has been described as a frequent complication of immune-mediated hemolytic anemia in the dog, and the presence of a circulating anticoagulant should be considered as a potential mechanism. 相似文献
934.
935.
DARIEN LAWRENCE BSc BVSC JAMIE R. BELLAH DVM Dipiomate ACVS D. J. MEYER DVM Dipiomate ACVIM Dipiomate ACVP L. ROTH DVM PhD Dipiomate ACVP 《Veterinary surgery : VS》1992,21(6):446-451
The use of a cholecystostomy catheter for temporary bile diversion was investigated in four cats with experimentally induced extrahepatic bile duct obstruction. Eighteen days after ligation of the common bile duct, a 6.5 F accordion catheter was placed in the gallbladder with a 22 g Hawkins needle-guide system through a paracostal incision. Biochemical parameters and fasting serum bile acids were monitored for 16 days. There were significant decreases in mean total bilirubin, aspartate aminotransferase, and fasting serum bile acids within 72 hours of bile diversion, and in mean alanine aminotransferase within 96 hours. Attitude and appetite improved, and the catheter was tolerated well. Positive bile cultures developed in three cats. Histologic changes in the gallbladder included mucosal ulcerations, a mixed inflammatory cellular infiltration, and fibrosis of the submucosa. 相似文献
936.
The severity of charcoal root disease of conifer seedlings (Abies concolor, A. magnified, Pinus jeffreyi, P. lambertiana, and Pseudotsuga menziesii) was a power function of the sclerotial density of the fungus (Macrophomina phaseolina) in nursery soil. 相似文献
937.
One hundred two fecal specimens from psittacine birds submitted to Veterinary Laboratory Services of the California Department of Food and Agriculture at Petaluma were screened for Chlamydia psittaci by a direct immunofluorescence assay using a fluorescein-labeled monoclonal antibody conjugate specific for Chlamydia sp. Results were compared with those obtained by isolation of chlamydia in cultures of McCoy mouse cells. The relative specificity of the direct fluorescent antibody test on fecal smears was 98.9% and the relative sensitivity was 62.5%. The results of this study suggested that the direct fluorescent antibody test was highly specific, and it proved to be a useful same-day antemortem diagnostic test for birds with symptomatic chlamydial infection. The use of centrifugation in the cell culture assay was found to significantly enhance the level of chlamydial infection in cell culture. 相似文献
938.
Ariana M.P. Nap Yvonne W.E.A. Pollak Walter E. van den Brom Ad Rijnberk DVM PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):302-303
Thyroidal 99m TcO4 (pertechnetate) uptake percentages were determined in unanesthetized euthyroid (n = 13) and hyperthyroid (n = 18) cats. Maximal uptakes were observed 60 minutes after IV injection of the radionuclide and ranged from 0.3 to 3.9% of the dose in euthyroid cats (median 2.23%) and from 5.2% to 23.9% of the dose in hyperthyroid cats (median 14.8%) ( P < .05). There were no overlaps in pertechnetate uptake percentages during any of the intervals evaluated. It is concluded that the optimal time for visualization of the thyroid by 99m TcO4 -scanning is 60 minutes after IV injection of the radionuclide. Calculation of the percentage uptake is of additional diagnostic value. 相似文献
939.
J E Sagartz D E Swayne K A Eaton J R Hayes K D Amass R Wack L Kramer 《Avian diseases》1992,36(2):282-289
Necrotizing typhlocolitis was diagnosed in 13 juvenile common rheas (Rhea americana) from three separate of geographically isolated Ohio flocks, with mortality ranging from 25% to 80%. At postmortem examination, a diphtheritic membrane covered ulcerated cecal mucosa. Histologically, cecal sections showed necrosis and granulomatous-to-suppurative inflammation that extended into the submucosa and often surrounded large eosinophilic colonies of bacteria. Warthin-Starry staining showed these colonies to be composed of entangled spirochetes that invaded the submucosa and frequently were present transmurally. Similar organisms were identified by Warthin-Starry staining in the cecum of a juvenile rhea from a fourth flock that histologically had mild lymphocytic typhlitis. Scanning and transmission electron microscopy demonstrated the presence of a spirochete in the ceca. Anaerobic culture yielded a gram-negative, beta-hemolytic spirochete. Coccidia, histomonads, and Salmonella spp. were consistently absent. 相似文献
940.
L Mishu G Callahan Z Allebban J M Maddux T C Boone L M Souza C D Lothrop 《Journal of the American Veterinary Medical Association》1992,200(12):1957-1964
Recombinant canine granulocyte colony-stimulating factor (rcG-CSF) was administered to clinically normal dogs, cyclic-hematopoietic dogs, and dogs undergoing autologous bone marrow transplantation, to determine whether rcG-CSF could be used to stimulate WBC production and function in normal and neutropenic dogs. To the normal dogs, rcG-CSF was administered by SC injection at rates of 1 microgram/kg of body weight, q 12 h; 2 micrograms/kg, q 12 h; or 5 micrograms/kg, q 12 h. A significant dose-dependent increase in the WBC count resulted from the stimulation of bone marrow progenitor cells. The increased WBC count was characterized by mature neutrophilia and monocytosis. Neutrophil myeloperoxidase and phagocytic activity were normal in rcG-CSF-treated normal dogs, demonstrating the production of normal functional neutrophils in response to rcG-CSF treatment. Recombinant canine G-CSF prevented neutropenia and associated clinical signs but did not completely eliminate the cycling of neutrophils in cyclic-hematopoietic dogs when it was administered at rates of 1 microgram/kg, q 12 h, and 2.5 micrograms/kg, q 12 h. The time to bone marrow reconstitution was not decreased in dogs treated with rcG-CSF at a rate of 2.5 micrograms/kg, q 12 h, for 13 days following autologous bone marrow transplantation. On the basis of our findings, we suggest that treatment with rcG-CSF is an effective way to stimulate myelopoiesis in dogs, but that the dose of rcG-CSF required to stimulate WBC production will vary depending on the cause of neutropenia. Recombinant canine G-CSF should be useful in stimulating production and maintaining function of WBC for treatment of clinical diseases seen commonly in veterinary practice. 相似文献