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81.
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AIMS: To investigate the cause of an outbreak of ovine abortion in 1996 in a flock of 300 two-tooth (rising 2-year-old) ewes vaccinated against Campylobacter fetus fetus infection and to subsequently characterise the strain of C. fetus fetus isolated from aborted foetuses. METHODS: Standard bacteriological methods were used to identify C. fetus fetus isolates which were then antigenically typed and subjected to pulsed-field gel electrophoresis (PFGE) and compared to the vaccine strain. RESULTS: C. fetus fetus was identified as the causal agent of the abortions despite the ewes having been vaccinated before ram introduction and at the time of ram removal. Four isolates cultured from aborted material were indistinguishable when compared using antigenic typing and PFGE, but all differed from the vaccine strain. CONCLUSIONS: Within the limitations of the available typing systems, it is proposed that PFGE may be a useful tool to establish the distribution and strain variation of C. fetus fetus. CLINICAL RELEVANCE: This field case indicates the need for further study of non-vaccine C. fetus fetus strains which cause abortion in vaccinated ewes, and of the importance of these strains to the New Zealand sheep industry.  相似文献   
83.
L I  WT Juan  CH Chiang  JH Chu 《Science (New York, N.Y.)》1996,272(5268):1626-1628
The microscopic particle motions from the crystal to the disordered state of a dusty plasma with micrometer-sized silicon dioxide particle suspensions in a radio-frequency glow discharge system were studied through an optical microimaging system. Small-amplitude random motion around the lattice sites of the crystal state, relative domain motion with varying boundaries, cooperative hopping in the liquid state, and highly disordered motion with increasing radio-frequency power were observed. Chaotic states with different spatial scales under the coherent and stochastic coupling between dust particles and self-organized background plasma fluctuations were also demonstrated.  相似文献   
84.
Observations with the High Resolution Imager on the Rontgensatellit reveal x-ray emissions from Jupiter's equatorial latitudes. The observed emissions probably result from the precipitation of energetic (>300 kiloelectron volts per atomic mass unit) sulfur and oxygen ions out of Jupiter's inner radiation belt. Model calculations of the energy deposition by such heavy ion precipitation and of the resulting atmospheric heating rates indicate that this energy source can contribute to the high exospheric temperatures(>800 kelvin at 0.01 microbar) measured by the Galileo probe's Atmospheric Structure Instrument. Low-latitude energetic particle precipitation must therefore be considered, in addition to other proposed mechanisms such as gravity waves and soft electron precipitation, as an important source of heat for Jupiter's thermosphere.  相似文献   
85.
The experimental fragmentation of landscapes of a natural ecosystem resulted in declines in the abundance and distribution of most species in the multispecies animal community inhabiting the landscapes and the extinction of many species. These declines caused the deterioration of the positive interspecific relation between local population abundance and distributional extent in this community. However, when patches were connected by habitat corridors, an immigration "rescue effect" arrested declines in both abundance and distribution and maintained the observed positive relation between them. These results demonstrate the importance of metapopulation dynamics and landscape connectivity for the persistence of populations in fragmented landscapes.  相似文献   
86.
From May 1, 1983 to April 1, 1985, 142 operations were performed on horses with signs of acute abdominal pain (colic), using a ventral midline incision. Seventy-eight horses lived for at least 15 days after surgery or had acute dehiscence and were included in the study. Seventy horses had surgery once, and 8 horses had surgery 2 or more times. Six-month follow-up evaluation was obtained for 66 horses that had 1 surgery and for 6 horses that had multiple surgeries. Incisional complications included drainage (including infection), acute dehiscence, hernia, and suture sinus formation. The effects of preoperative peritoneal fluid presence, enterotomy or resection, suture material and pattern used in the linea alba, type of skin closure and use of a sutured-on stent bandage on the incidence of incisional complications were investigated. The complication of incisional infection rate associated with a near-far-far-near suture pattern vs simple interrupted pattern in the linea alba was the only statistically significant (P less than 0.05) difference observed.  相似文献   
87.
Alterations of acid-base status, and fluid and electrolyte balance subsequent to exercise in Thoroughbred racehorses in North America have not been well-characterized. Des-cribed here are the results of an observational study conducted to characterize changes in fluid and electrolytes following strenuous exercise of 16 Thoroughbreds under routine training conditions. Changes following strenuous exercise were determined for the following variables: serum concentrations of sodium (Na), potassium (K), chloride (Cl) and protein; pH of blood; osmolality of plasma and urine; body weight; and, fractional urinary excretion (FE) of Na, K and Cl. The following changes occurred during exercise: increased concentration of Na in blood; increased FE of Na; decreased concentration of Cl in blood; decreased FE of Cl; increased urinary and plasmal osmolality; weight-loss; decreased pH of blood; and, increased concentration of lactic acid. The concurrent decreased concentration of chloride in plasma and acidemia in these horses differed from the hypochloremic, metabolic alkalosis previously described among endurance horses. Acidemia was attributed to production of lactic acid by anaerobic glycolysis.  相似文献   
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Objective To determine whether a drug detected in the blood or urine of a racing animal could have penetrated through the skin from a topically applied preparation.
Design Blood and urine of dogs and horses were analysed after topical administration of three common nonsteroidal anti-inflammatory preparations.
Experimental method Dimethylsulphoxide was analysed using a gas chromatograph with a flame photometric detector. Phenylbutazone, its metabolites and lignocaine were analysed using a gas chromatograph with a mass selective detector.
Results Dimethylsulphoxide, phenylbutazone and ligno-caine were detected in dog urine after muliple applications of the preparations. The maximum concentration of dimethyl-sulphoxide in dog urine correlated with the concentration of dimethylsulphoxide in the preparation. Phenylbutazone penetrated the skin more effectively from the cream than from the solution or gel preparations. This penetration was independent of the concentration of dimethylsulphoxide.
Conclusion The superior penetration of phenylbutazone from the cream can be explained by it being present as a neutral molecule in an hydrophobic medium. It is proposed that phenylbutazone penetrates the skin of greyhounds most effectively by a hydrophobic lipid route which is likely to be different from the path by which dimethylsulphoxide penetrates the skin.  相似文献   
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