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1.
Haematological and biochemical investigations were performed on 14 koalas with uncomplicated cystitis, 8 with complicated cystitis, 8 with conjunctivitis, 8 with lymphosarcoma, and 14 with miscellaneous diseases. Changes were limited and inconsistent in individual koalas with uncomplicated cystitis and conjunctivitis. In contrast, individual koalas with complicated cystitis were more likely to have anaemia, leukocytosis due to neutrophilia, hypoproteinaemia due to hypoalbuminaemia, and azotaemia due to elevated urea concentration. Although these changes were non-specific they did allow assessment of prognosis for survival and response to treatment. Koalas with lymphosarcoma were invariably anaemic, leukaemic, azotaemic and hypoalbuminaemic. Elevated enzymes (aspartate transaminase [AST]. lactate dehydrogenase [LD] and gamma glutamyl transferase [GGT]) were more common in koalas with lymphosarcoma. Koalas affected by miscellaneous conditions showed variable changes but once again anaemia, leukocytosis, azotaemia, elevated AST and LD, and hypoalbuminaemia were not uncommon. On the basis of these findings a minimal profile is suggested for the investigation of sick koalas and would include haematocrit, total and differential leukocyte counts, urea, total protein and albumin concentrations and AST, GGT and LD activities.  相似文献   
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Ecophysiological simulation models provide a quantitative method to predict the effects of management practices, plant characteristics and environmental factors on crop and weed growth and competition. The INTERCOM interplant competition model was parameterised, calibrated by monoculture data for three cowpea (Vigna unguiculata) genotypes that differed in growth habit, common sunflower (Helianthus annuus) and common purslane (Portulaca oleracea), and used to simulate competition of cowpea cover crops with sunflower or purslane. The simulation results were compared with observations from field competition experiments in 2003 and 2004. INTERCOM more accurately simulated actual field data for the competition of cowpea genotypes and sunflower than companion field experiments for the competition of cowpea and purslane. The validated simulation model of cowpea and sunflower at two densities was used to study the effects of cowpea growth habit on final biomass production of cowpea and sunflower. The model suggested that erect growth habit was more competitive than semi‐erect and prostrate growth habit, when cowpea genotypes were grown with sunflower. Cowpea leaf area distribution was important to higher cowpea biomass production, while cowpea height growth was important to reduce sunflower biomass. Our simulation approach is suggested as a method for crop breeders to gauge the likely success of selection for competitive crops before undertaking expensive long‐term breeding experiments.  相似文献   
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Gastric dilatation-volvulus (GDV) is a dramatic and enigmatic disease of large and giant breed dogs characterised by the rapid accumulation of gas in the stomach. This causes gastric dilatation, twisting of the stomach about its long axis, compression of surrounding organs, hypovolaemic and cardiogenic shock, and if untreated, death. It has been estimated that the disease afflicts approximately 60,000 dogs in the USA each year with a mortality rate ranging from 7 to 60 per cent depending on accessibility to adequate veterinary care. The cause is unknown. While diet was at one time believed to be associated with the genesis of the disease, critical review of available data provides no evidence to support this hypothesis. A variety of predisposing or risk factors have been identified but none is suspected of being the cause, indeed, the disorder may have a multiple aetiology. Current thinking suggests that the final common pathway in the development of GDV may be an inhibition of gastric motility and emptying. This could come about through a primary disruption of normal gastric electrical patterns or through the effect of extraneous stressful events that disrupt gastric motility. After dilatation a series of potentially lethal events is unleashed which include compression of the caudal vena cava, pooling of blood in the microcirculation of the viscera and hindlimbs, metabolic acidosis, gastric necrosis, cardiac arrhythmias, disseminated intravascular coagulation, hypotensive and cardiogenic shock and death. Nevertheless, even advanced cases can survive if treated appropriately. If the cause could be identified logical prophylaxis might follow. Studies at the University of Florida have failed to demonstrate any effect of diet on gastric function in large breed dogs, suggesting that diet is probably not the cause of the disease. Researchers at Colorado State University also found no association with diet in clinical patients. Recent studies at the University of Florida have revealed distinct abnormalities in gastric electrical activity in GDV patients. In human patients these abnormalities, called dysrhythmias, have been associated with gastric distention, bloating, delayed emptying, nausea and retching. Unfortunately, dysrhythmias are also present, albeit to a lesser degree, in experimental GDV. These findings leave unanswered the question as to whether abnormalities in gastric motility play a role in the genesis of GDV.  相似文献   
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The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.  相似文献   
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A grading system for lymphocytic plasmacytic colitis in dogs   总被引:1,自引:0,他引:1  
Colonic mucosal samples were obtained every 4 weeks for 13 months from 6 clinically normal dogs and from 47 dogs with a clinical diagnosis of chronic inflammatory bowel disease. All samples were graded on a scale of 0-5, based upon the quantity of lymphocytes and plasma cells in the lamina propria, epithelial changes, and the presence of ulcers and erosions. A grade of less than or equal to 2.0 was considered normal and was assigned to 77 of 78 samples from clinically normal dogs and 28 of 48 samples from dogs with diarrhea. A transient increase in cellularity was noted in 1 sample from 1 control dog. Nineteen dogs with clinical disease had obvious histologic abnormalities. The grading scheme described provides the pathologist with an objective criterion for the microscopic evaluation of colonic mucosal samples obtained by endoscopic techniques and offers clinicians a method of assessing the dog's progress and response to therapy.  相似文献   
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We have isolated a compound responsible for the cytokinin activity of soluble RNA from Escherichia coli. The structure, indicated as 6-(3-methyl-2-butenylamino)-2-methylthio-9-beta-D-ribofuranosylpurine, C(16)H(23)N(5)0(4)S, on the basis of low-and high-reso!ution mass spectrometry, was established by unequivocal synthesis. The mass spectra, chromatographic behavior, and ultraviolet spectra of the compounds from natural and synthetic sources were identical.  相似文献   
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