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排序方式: 共有643条查询结果,搜索用时 15 毫秒
91.
Effect of lasalocid on weight gains, ruminal fermentation and forage intake of stocker cattle grazing winter wheat pasture 总被引:1,自引:0,他引:1
Fifty fall-weaned heifers with initial weights of 209 kg (yr 1) and 222 kg (yr 2) were used to determine effects of lasalocid on weight gains, forage intake and ruminal fermentation of stocker cattle grazing winter wheat pasture. The heifers grazed a single wheat pasture for about 100 d each year, and were individually fed 1.06 kg of supplement (6 d/wk) pro-rated to supply 0, 100 or 200 mg lasalocid.head-1.d-1. Also, eight mature Hereford steers with large rumen cannula were used to evaluate further effects of lasalocid (0 or 300 mg) on ruminal fermentation during two grazing periods (immature and mature wheat forage) of yr 2 and an additional third year. Daily gains of heifers fed 200 mg lasalocid/d were .11 kg greater (P less than .05) than those of heifers fed 0 or 100 mg lasalocid/d. One hundred milligrams lasalocid did not increase weight gains. Digestibilities of forage dry matter (DM) and organic matter (OM) were similar (P greater than .05) among treatments, and lasalocid did not affect (P greater than .10) forage intake. Ruminal ammonia concentrations (10.57, 15.22 and 17.81 mg/dl +/- 1.71) were increased (P less than .05) by both levels of lasalocid in yr 1, but differences among treatment means of 8.32, 11.95 and 11.66 (SE +/- 1.44) were not significant in yr 2. Lasalocid did not consistently affect total volatile fatty acids concentrations. The acetic:propionic acid ratios in heifers were not different (P greater than .05) among treatments, but were decreased (P less than .10) by lasalocid in cannulated steers.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
92.
Automated and Unbiased Image Analyses as Tools in Phenotypic Classification of Small-Spored Alternaria spp 总被引:1,自引:0,他引:1
ABSTRACT For more than 25 years, controversy has surrounded the characterization and differentiation of small-spored Alternaria spp. And, therefore, the application of names of several species that are involved in the pathology of diseases related to host-specific toxin production. The name A. alternata often has been broadly applied to various morphologically and chemically distinct groups of isolates from different hosts. The purpose of this study was to develop and evaluate automated and unbiased image analysis systems that will analyze different phenotypic characters and facilitate testing and application of the morphological species concept in Alternaria taxonomy. Host-specific toxin-producing Alternaria isolates assigned to five morpho-species were compared with representative isolates of morphologically distinct A. alternata. Combined results of growth rates at different temperatures, colony morphology, and metabolite profiles were found to be useful in characterization and differentiation of small-spored Alternaria spp. when standardized conditions are applied and representative isolates employed for comparison. 相似文献
93.
Scortichini M Rossi MP Loreti S Bosco A Fiori M Jackson RW Stead DE Aspin A Marchesi U Zini M Janse JD 《Phytopathology》2005,95(11):1316-1324
ABSTRACT Thirty-eight bacterial strains isolated from hazelnut (Corylus avellana) cv. Tonda Gentile delle Langhe showing a twig dieback in Piedmont and Sardinia, Italy, were studied by a polyphasic approach. All strains were assessed by fatty acids analysis and repetitive sequence-based polymerase chain reaction (PCR) fingerprinting using BOX and ERIC primer sets. Representative strains also were assessed by sequencing the 16S rDNA and hrpL genes, determining the presence of the syrB gene, testing their biochemical and nutritional characteristics, and determining their pathogenicity to hazelnut and other plants species or plant organs. Moreover, they were compared with reference strains of other phytopathogenic pseudomonads. The strains from hazelnut belong to Pseudomonas syringae (sensu latu), LOPAT group Ia. Both fatty acids and repetitive-sequence-based PCR clearly discriminate such strains from other Pseudomonas spp., including P. avellanae and other P. syringae pathovars as well as P. syringae pv. syringae strains from hazelnut. Also, the sequencing of 16S rDNA and hrpL genes differentiated them from P. avellanae and from P. syringae pv. syringae. They did not possess the syrB gene. Some nutritional tests also differentiated them from related P. syringae pathovars. Upon artificial inoculation, these strains incited severe twig diebacks only on hazelnut. Our results justify the creation of a new pathovar because the strains from hazelnut constitute a homogeneous group and a discrete phenon. The name of P. syringae pv. coryli is proposed and criteria for routine identification are presented. 相似文献
94.
95.
E B Breitschwerdt T T Brown E V De Buysscher B R Andersen D E Thrall E Hager G Ananaba M A Degen M D Ward 《American journal of veterinary research》1987,48(7):1054-1062
Eight closely related Doberman Pinschers with chronic rhinitis and pneumonia had normal or increased numbers of structurally normal leukocytes. Serum concentrations of immunoglobulins and complement were above or within normal ranges. Lymphocyte transformation indices for 3 mitogens were normal in 7 of the 8 dogs; the remaining dog had low values for all mitogens. Neutrophils phagocytized bacteria normally, but had impaired bactericidal ability. The bactericidal defect may have been related to the inability of neutrophils to generate normal numbers of oxygen radicals after stimulation, as determined by decreased ability of neutrophils to reduce nitroblue tetrazolium and to produce superoxide following opsonized zymosan stimulation. These observations, plus finding chronic inflammatory disease in the lungs of one dog, indicated that the disease may have some similarity to chronic granulomatous disease or to complement receptor deficiency in man. 相似文献
96.
McCann ME Andersen DR Zhang D Brideau C Black WC Hanson PD Hickey GJ 《American journal of veterinary research》2004,65(4):503-512
OBJECTIVE: To determine cyclooxygenase-2 (COX-2) selectivity, pharmacokinetic properties, and in vivo efficacy of ML-1,785,713 in dogs. ANIMALS: 21 healthy male and female mixed-breed dogs and 24 healthy male Beagles. PROCEDURE: Selectivity of ML-1,785,713 for inhibiting COX-2 was determined by comparing the potency for inhibiting cyclooxygenase-1 (COX-1) with that of COX-2 in canine blood. Pharmacokinetic properties were determined after i.v. (2 mg/kg) and oral (8 mg/kg) administration in female mixed-breed dogs. In vivo efficacy was evaluated in male mixed-breed dogs with urate crystal-induced synovitis. Prophylactic efficacy was evaluated by administering ML-1,785,713 two hours before induction of synovitis whereas therapeutic efficacy was determined by administering ML-1,785,713 one hour after induction of synovitis. RESULTS: Blood concentrations that resulted in 50% inhibition of COX-1 and COX-2 activity in vitro were 119.1 microM and 0.31 microM, respectively, and selectivity ratio for inhibiting COX-2 relative to COX-1 was 384. ML-1,785,713 had high oral bioavailability (101%), low systemic clearance (77 mL/min/kg), and an elimination half-life of 5.9 hours. ML-1,785,713 was efficacious when administered prophylactically and therapeutically to dogs with urate crystal-induced synovitis. CONCLUSIONS AND CLINICAL RELEVANCE: ML-1,785,713 is a novel, potent COX-2 inhibitor that is the most selective COX-2 inhibitor described for use in dogs to date. ML-1,785,713 has oral bioavailability and low systemic clearance that is comparable to other non-steroidal anti-inflammatory drugs. It is effective after prophylactic and therapeutic administration in attenuating lameness in dogs with urate crystal-induced synovitis. Drugs that specifically inhibit COX-2 and not COX-1 at therapeutic doses may have an improved tolerability profile, compared with nonselective non-steroidal anti-inflammatory drugs. 相似文献
97.
Vervenne RA Jones SL van Soolingen D van der Laan T Andersen P Heidt PJ Thomas AW Langermans JA 《Veterinary immunology and immunopathology》2004,101(1-2):61-71
To examine the effect of recombinant bovine interferon-gamma (rbIFN-gamma) on cattle persistently infected with bovine leukemia virus (BLV), BLV-infected cattle were inoculated intraperitoneally with IFN-gamma. All cattle were febrile after inoculation with IFN-gamma and then recovered within 48 h. Flow cytometric analysis showed that the numbers of CD4+ and CD8+ T cells were decreased for 2-3 days and then their numbers were recovered. The number of gammadelta T cells increased after the fever. In contrast, the number of IgM+ lymphocytes remained low for about 1 week. Moreover, the numbers of syncytia produced by peripheral blood lymphocytes decreased and remained low compared to that before IFN-gamma administration. These results suggest that IFN-gamma induces the up-regulation of gammadelta T cells, decreases the number of IgM+ lymphocytes and suppresses the growth of BLV in BLV-infected cattle in vivo. 相似文献
98.
Andersen PR Tyrrell P 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2004,5(2):327-330
Prior to the widespread use of vaccination for the control of feline immunodeficiency virus (FIV) infection, diagnosis was made by the detection of antibodies against FIV. A number of commercial animal side tests perform quite well for this determination, with positive predictive values between 91 and 100% and negative predictive values between 96 and 100%. Furthermore, results of these tests could be confirmed by western blot analysis of FIV test-positive sera. Currently, a killed whole virus FIV vaccine has been made available to practitioners. Vaccinated cats seroconvert by ELISA and western blot, making presently available diagnostic tests, which rely on antibody detection, useless in cats after vaccination. The advisory panels of the American Association of Feline Practitioners and Academy of Feline Medicine both recommend testing for feline leukemia virus antigen and FIV antibody before vaccination. 相似文献
99.
Andersen CB Ballut L Johansen JS Chamieh H Nielsen KH Oliveira CL Pedersen JS Séraphin B Le Hir H Andersen GR 《Science (New York, N.Y.)》2006,313(5795):1968-1972
In higher eukaryotes, a multiprotein exon junction complex is deposited on spliced messenger RNAs. The complex is organized around a stable core, which serves as a binding platform for numerous factors that influence messenger RNA function. Here, we present the crystal structure of a tetrameric exon junction core complex containing the DEAD-box adenosine triphosphatase (ATPase) eukaryotic initiation factor 4AIII (eIF4AIII) bound to an ATP analog, MAGOH, Y14, a fragment of MLN51, and a polyuracil mRNA mimic. eIF4AIII interacts with the phosphate-ribose backbone of six consecutive nucleotides and prevents part of the bound RNA from being double stranded. The MAGOH and Y14 subunits lock eIF4AIII in a prehydrolysis state, and activation of the ATPase probably requires only modest conformational changes in eIF4AIII motif I. 相似文献
100.
Damgaard LH Korsgaard IR Simonsen J Dalsgaard O Andersen AH 《Journal of animal science》2006,84(6):1338-1350
The objective of this study was, by means of simulation, to quantify the effect of ignoring individual heterogeneity in Weibull sire frailty models on parameter estimates and to address the consequences for genetic inferences. Three simulation studies were evaluated, which included 3 levels of individual heterogeneity combined with 4 levels of censoring (0, 25, 50, or 75%). Data were simulated according to balanced half-sib designs using Weibull log-normal animal frailty models with a normally distributed residual effect on the log-frailty scale. The 12 data sets were analyzed with 2 models: the sire model, equivalent to the animal model used to generate the data (complete sire model), and a corresponding model in which individual heterogeneity in log-frailty was neglected (incomplete sire model). Parameter estimates were obtained from a Bayesian analysis using Gibbs sampling, and also from the software Survival Kit for the incomplete sire model. For the incomplete sire model, the Monte Carlo and Survival Kit parameter estimates were similar. This study established that when unobserved individual heterogeneity was ignored, the parameter estimates that included sire effects were biased toward zero by an amount that depended in magnitude on the level of censoring and the size of the ignored individual heterogeneity. Despite the biased parameter estimates, the ranking of sires, measured by the rank correlations between true and estimated sire effects, was unaffected. In comparison, parameter estimates obtained using complete sire models were consistent with the true values used to simulate the data. Thus, in this study, several issues of concern were demonstrated for the incomplete sire model. 相似文献