Toxigenic type D Pasteurella multocida in New South Wales pig herds—prevalence and factors associated with infection     

I A Gardner  G J Eamens  M J Turner  C L Hornitzky 《Australian veterinary journal》1989,66(10):318-321

Between March and July 1987, a study was undertaken to determine the prevalence of and factors associated with toxigenic type D Pasteurella multocida infection in New South Wales pig herds. Toxigenic type D P. multocida was isolated from the nasal cavities of pigs in one (2%) of 50 randomly selected herds. Toxigenic isolates were also recovered from 2 (8%) of a separate group of 25 herds that had purchased pigs from a known infected piggery in South Australia (herd SA). Snout abnormalities were present in 9.4%, 3.2% and 1.8% of grower pigs in the 3 affected herds. Isolation of toxigenic P. multocida was significantly associated (p less than 0.0001) with the occurrence of clinically affected pigs in the herd. Purchase of at least 5 pigs from herd SA was associated with an elevated risk (p less than 0.05) of isolation of toxigenic P. multocida.  相似文献   

Response of the Rieger begonia to ozone and sulphur dioxide     

J.O. Gardner  D.P. Ormrod 《Scientia Horticulturae》1976,5(2):171-181

Ozone (O₃) and sulphur dioxide (SO₂) are at present the two most pervasive air pollutants in the urban and suburban areas in which most Rieger begonias are grown. These air pollutants have been shown to impair crop productivity and quality in many other species. Controlled environment experiments were therefore conducted to elucidate the responses of ‘Schwabenland Red’ to separate or bombined O₃ and SO₂ at different growth stages.Plants at the early vegetative or prefloral stages had much more leaf damage after combined O₃ + SO₂ than after separate gases at 15 p.p.h.m. O₃ or 60 p.p.h.m. SO₂ for 5 days in a synergistic type of response. Exposure for an additional day at twice these concentrations greatly increased leaf damage. Growth reductions were not found after 2 weeks but delaying measurements until 8 weeks after treatment revealed some growth reductions.Experiments were conducted with flowering plants using O₃ of 0, 10, 20 or 30 p.p.h.m. in all combinations with SO₂ at 0, 60, 120 or 180 p.p.h.m. Fully developed leaves were damaged, and undamaged leaves were smaller and lighter on plants exposed to 20 p.p.h.m. or more O₃, 120 p.p.h.m. or more SO₂, or any combination of O₃ and SO₂ at or above 10 and 60 p.p.h.m., respectively.  相似文献   

The effect of the molluscicide Frescon on smooth and cross-striated muscles of Lymnaea stagnalis and Helix aspersa     

B.L. Brezden  D.R. Gardner 《Pesticide biochemistry and physiology》1983,20(3):259-268

The molluscicide Frescon (N-(triphenylmethyl)morpholine) induces prolonged, irreversible contractions (contractures) in the isolated heart ventricle, penis retractor, and foot muscles of the aquatic snail Lymnaea stagnalis. It also causes contracture of the penis retractor muscle, but not the heart ventricle, of the terrestrial snail Helix aspersa. Since Frescon-induced contracture is not accompanied by a depolarization of the sarcolemma of Lymnaea heart ventricle muscle cells, it is suggested that the action of this molluscicide is associated with a membrane potential-independent activation of the contractile machinery. The rapid response of Lymnaea musculature to Frescon suggests that the direct contracture-inducing action of this molluscicide could explain its toxicity to the whole animal.  相似文献   

Enzootic pneumonia: comparison of cough and lung lesions as predictors of weight gain in swine.   总被引：4，自引：0，他引：4       下载免费PDF全文

C R Morris  I A Gardner  S K Hietala    T E Carpenter 《Canadian journal of veterinary research》1995,59(3):197-204

A prospective cohort study was undertaken in a commercial swine herd to determine the relationship between weight gain and the occurrence of enzootic pneumonia (EP). Estimates of the association between EP and weight gain were obtained from multiple linear regression models, using coughing episodes or slaughter checks as indicators of EP status. Models were estimated for pigs in 2 different age groups: roasters (n = 1084, sold at 32 to 50 kg) and market hogs (n = 1162, sold at 100 to 110 kg). The relationship between presence of lung lesions at slaughter and previous coughing episodes was also investigated. Throughout the study period, clinical evaluations were performed weekly, and coughing episodes recorded for each pig. Lungs were inspected at slaughter, and scores were expressed as the percentage of the lung with gross pneumonic lesions. Coughing and lung scores were significantly correlated, after adjusting for other covariates (R = 0.32 and 0.59, respectively, for market hogs and roasters). However, the agreement beyond chance between coughing history and lung lesions at slaughter was poor among both roasters and market hogs (kappa = 0.17 and 0.07, respectively). Although very specific, weekly assessment of coughing was not a sensitive indicator of lung lesions at slaughter. In multiple regression, lung score was a highly significant predictor of lower final weight in pigs of both age groups (P < 0.001 in the selected regression models).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Response in mice to erythropoiesis regulatory factors     

J P Lewis  C S Wright  R R Moores  W A Neal  E T Welch  L L Smith  E Gardner  W G Lewis 《American journal of veterinary research》1973,34(10):1367-1368

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Neutral models for the analysis of broad-scale landscape pattern   总被引：47，自引：19，他引：28  

Robert H. Gardner  Bruce T. Milne  Monica G. Turnei  Robert V. O'Neill 《Landscape Ecology》1987,1(1):19-28

The relationship between a landscape process and observed patterns can be rigorously tested only if the expected pattern in the absence of the process is known. We used methods derived from percolation theory to construct neutral landscape models,i.e., models lacking effects due to topography, contagion, disturbance history, and related ecological processes. This paper analyzes the patterns generated by these models, and compares the results with observed landscape patterns. The analysis shows that number, size, and shape of patches changes as a function of p, the fraction of the landscape occupied by the habitat type of interest, and m, the linear dimension of the map. The adaptation of percolation theory to finite scales provides a baseline for statistical comparison with landscape data. When USGS land use data (LUDA) maps are compared to random maps produced by percolation models, significant differences in the number, size distribution, and the area/perimeter (fractal dimension) indices of patches were found. These results make it possible to define the appropriate scales at which disturbance and landscape processes interact to affect landscape patterns.  相似文献   

Haematological and biochemical findings in bovine post-parturient haemoglobinuria and the accompanying Heinz-body anaemia.     

D E Gardner  D Martinovich  D A Woodhouse 《New Zealand veterinary journal》1976,24(6):117-122

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Evidence that Frescon-induced contractures in Lymnaea stagnalis muscles do not depend on intracellular calcium stores: A comparison with caffeine action     

B.L. Brezden  D.R. Gardner 《Pesticide biochemistry and physiology》1983,20(3):278-285

The action of the molluscicide Frescon, which induces contractures in smooth and cross-striated muscles of the freshwater snail Lymnaea stagnalis, was compared with the action of caffeine. The results indicate that the latter agent promotes contractions in Lymnaea muscles by releasing Ca²⁺ from intracellular stores. Such a release could not be attributed to the action of Frescon. Furthermore, the molluscicide did not appear to alter muscle function at the level of the contractile apparatus as it did not affect the time course of caffeine-induced contractions. These results favor the hypothesis that Frescon increases sarcolemmal Ca²⁺ permeability.  相似文献   

Serum gamma glutamyl transferase activity in horses with right or left dorsal displacements of the large colon     

Gardner RB  Nydam DV  Mohammed HO  Ducharme NG  Divers TJ 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2005,19(5):761-764

The purpose of this study was to test the hypothesis that horses with right dorsal displacement of the large colon (RDDLC) have elevations in serum gamma glutamyl transferase (GGT) activity when compared with horses with left dorsal displacement of the large colon (LDDLC). Medical records from 37 horses with RDDLC and 48 horses with LDDLC were reviewed. Horses were included for study if the RDDLC or LDDLC was confirmed by exploratory laparotomy or postmortem examination and if a serum GGT measurement was obtained within 24 hours before surgery. The proportion of horses with GGT activity within or above the reference range was determined. Of 37 horses, 18 (49%; exact binomial 95% confidence interval, 32-66%) with RDDLC and, of 48 horses, 1 (2%; 95% CI, 0-11%) with LDDLC had GGT above the reference range. Horses with RDDLC had higher serum GGT than did horses with LDDLC. Of 37 horses, 36 (97%) with RDDLC were discharged with a good prognosis and none returned as a result of hepatic disease. Evaluation of surgical and postmortem examinations revealed that positioning of the colon in horses with RDDLC results in compression of the bile duct, which can cause extrahepatic bile duct obstruction and a subsequent elevation in serum GGT activity.  相似文献   

FIELD AND EXPERBMENTAL INVESTIGATION OF "WALK-ABOUT" DISEASE OF HORSES (KIMBERLEY HORSE DISEASE) IN NORTHERN AUSTRALIA: OROTALARIA POISONING IN HORSES. PART I.     

A. L. Bose  B.V.Se.  C. A. Gardner  †  J. D. McConnell  B.V.Sc. L. B. Bull  C.B.B  D.V.Sc  F.A.A‡ 《Australian veterinary journal》1957,33(2):25-33

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