Coupled 186Os and 187Os evidence for core-mantle interaction     

AD Brandon  RJ Walker  JW Morgan  MD Norman  HM Prichard 《Science (New York, N.Y.)》1998,280(5369):1570-1573

Osmium isotopic analyses of picritic lavas from Hawaii show enrichments in the osmium-186/osmium-188 ratio (186Os/188Os) of 0. 008 to 0.018%, relative to a chondritic upper mantle, that are positively correlated with enrichments in 187Os/188Os of 5.4 to 9.0%. The most viable mechanism to produce these coupled 186Os and 187Os enrichments is by addition of 0.5 to 1 weight percent of outer core metal to a portion of the D" layer and subsequent upwelling of the mixture. These data suggest that some plumes originate at the core-mantle boundary and that Os isotopes may be used to distinguish plumes derived from shallow versus deep mantle sources.  相似文献   

Brain damage in sheep from penetrating captive bolt stunning     

JW FINNIE  J. MANAVIS  PC BLUMBERGS  GE SUMMERSIDES 《Australian veterinary journal》2002,80(1):67-69

Objective To determine the severity and distribution of structural changes in the brains of adult sheep stunned by penetrating captive bolt.
Procedure The unconstrained heads of ten, anaesthetised, unhorned, 2-year-old Merino sheep were impacted at the summit of the head with a penetrating captive bolt pistol. Six sheep were ventilated and four received no respiratory support. Two hours after impact, brains from the six ventilated sheep were perfusion-fixed with 4% paraformaldehyde. Sixteen whole, serial coronal sections from each brain were stained with haematoxylin and eosin and immunohistochemi-cally for amyloid precursor protein, a sensitive marker of axonal and neuronal reaction in the brain after trauma. Pathological changes in these brains were then quantified by morphometric analysis.
Results Structural change in all impacted brains was a mixture of focal injury around the wound track and more widely distributed damage in the cerebral hemispheres, cerebellum and brainstem, but varied considerably in severity between individual sheep. All nonventilated sheep died rapidly following respiratory arrest.
Conclusions After penetrating captive bolt stunning, damage to the central reticular formation, axonal connections, and the cortical mantle is the likely reason for failure of respiratory control and traumatic loss of consciousness.  相似文献   

Factors associated with the effectiveness of antibiotic treatment for ovine virulent footrot     

D. JORDAN  JW PLANT†  HI NICOL‡  TM JESSEP  CJ SCRIVENER 《Australian veterinary journal》1996,73(6):211-215

Factors associated with the proportion of sheep cured of virulent footrot after antibiotic treatment were studied in a field trial under dry environmental conditions. From 2 similar flocks, 1091 Merino sheep weighing about 50 kg and infected with virulent footrot received an intramuscular injection of either 12 mL of a mixture of penicillin (250 mg/mL) and streptomycin (250 mg/mL), 6 mL of long acting oxytetracycline (200 mg/mL) or 6 mL of a mixture of lincomycin (50 mg/mL) and spectinomycin (100 mg/mL). Variables that were significantly associated with the proportion of sheep cured were: the type of antibiotic used, the number of feet infected and the flock from which the sheep came. There was an interaction between antibiotic type and number of feet infected and between antibiotic type and flock in association with the proportion of sheep cured. The extent of paring and the occurrence of blowfly strike in footrot lesions treated with diazinon had no significant association with the proportion of sheep cured.  相似文献   

An immunohistochemical study of plasma albumin extravasation in the brain of mice after the administration of Clostridium perfringens type D epsilon toxin     

JW FINNIE  P. HAJDUK 《Australian veterinary journal》1992,69(10):261-262

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An Anticoagulant for Transport of Bovine Blood          下载免费PDF全文

V.E. Valli  B.J. McSherry  G.E. Fountain  L. Friesen  P. Dwyer    C.M. Forsberg 《The Canadian veterinary journal. La revue veterinaire canadienne》1980,21(9):252-256,257

Various anticoagulant were assessed in order to develop a transport media for bovine blood which would improve leukocyte stability. The effects of time, disease in the donor and different personnel and laboratory equipment were also tested.

The transport media most effective for leukocyte stability was found to be Titriplex IV. This is a modification of Titriplex I by the inclusion of acetylsalicyclic acid to prevent cellular clumping and by the removal of methylene blue. Anticoagulant citrate dextroseformalin-ASA performed equally well for transport but cellular morphology was impaired.

Febrile or neoplastic disease in the donor animal did not alter the efficiency of the formalin containing anticoagulants.

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Plasma beta-endorphin and adrenocorticotrophin in young horses in training     

RN McCARTHY  LB JEFFCOTT  JW FUNDER†  M FULLERTON†  IJ CLARKE† 《Australian veterinary journal》1991,68(11):359-361

A controlled period of submaximal exercise on a treadmill was used as a standardised stress test in 6 young horses to monitor the effects of training. Circulating plasma concentrations of immunoreactive beta-endorphin (IR beta-EP) were measured before, during and after the exercise period. The stress test was conducted on 3 occasions during an intensive training program lasting 14 weeks. In week 3 a marked increase in plasma IR beta-EP (P = 0.003) was demonstrated as a result of training, but by the last exercise test performed in week 9 no significant increase in plasma IR beta-EP concentrations could be detected. During the training period the basal concentrations of plasma IR beta-EP significantly decreased (P = 0.0059). Plasma adrenocorticotrophin (ACTH) did not increase during exercise, although there was a trend of decreasing basal plasma ACTH by the end of the training period. It was concluded that a standardised work test acted as a mild stress to unfit horses, but as the horses' fitness increased the hormonal response to exercise diminished. Basal plasma beta-EP concentrations were decreased with increasing fitness.  相似文献   

An ELISA test to detect antibody to $\text{Bordetella bronchiseptica}$     

C. Dees  M.W. Fountain  V.S. Panangala  L.J. Swango  R.D. Schultz 《Veterinary immunology and immunopathology》1982,3(6):539-545

An enzyme-linked immunosorbant assay (ELISA) was developed to measure antibody to $\text{Bordetella bronchiseptica}$ in dogs. The ELISA test was more rapid and sensitive and required 50 to 150 times less antigen than the amount of antigen required for the conventional tube agglutination test. A survey of 50 canine serum samples using ELISA suggested that 8% of all sera had titers greater than 1:64, 56% had titers of 1:8 to 1:64, and 36% had titers of less than 1:8. The mean titer of survey sera was 1:46 and the median titer was 1:16. Serum antibody responses in dogs inoculated with a commercially available bacterin were compared with responses in dogs inoculated with experimental endotoxin depleted bacterin.  相似文献   

Enhanced intraphagocytic killing of Brucella abortus in bovine mononuclear cells by liposomes-containing gentamicin   总被引：3，自引：0，他引：3  

C Dees  M W Fountain  J R Taylor  R D Schultz 《Veterinary immunology and immunopathology》1985,8(1-2):171-182

In vitro intraphagocytic killing of Brucella abortus in bovine mononuclear leukocytes was enhanced by cationic, anionic, and neutral multilamellar liposomes-containing gentamicin. Free gentamicin not entrapped in liposomes. and liposomes without antibiotic did not enhance intraphagocytic killing of B. abortus in bovine phagocytes. In vivo killing of B. abortus in guinea pigs was also enhanced by liposomes-containing gentamicin when compared to free gentamicin. Liposomes-containing alpha tocopherol acetate failed to enhance in vivo killing of B. abortus.  相似文献   

Effects of antibiotic therapy at drying off on mastitis in the dry period and early lactation     

JW BROWNING  GA MEIN  M. BARTON  TJ NICHOLLS  P. BRIGHTLING 《Australian veterinary journal》1990,67(12):440-442

Four strategies for selecting cows for intramammary therapy with benzathine cloxacillin at drying off were compared in 12 Victorian dairy herds. The bacteriological status of all quarters of all (1044) cows was determined just before drying off, within 2 d of calving, and again 3 to 5 months after calving. All cases of clinical mastitis (from calving to mid-lactation) were recorded. Cows not infected at drying off were allocated randomly to 2 subgroups of approximately 350 cows each: not infected, not treated (NI-NT), or not infected, all quarters treated (NI-AT). New infection rates in the dry period (3.8% for NI-NT vs 2.1% for NI-AT) and in early lactation (4.1% for NI-NT vs 3.9% for NI-AT) were low and these differences were not significant. Incidence of clinical mastitis in early lactation was almost 50% higher for the treated group of uninfected cows compared with the untreated group (0.05 less than p less than 0.1). Cows infected in one or more quarters at drying off were split randomly into 2 subgroups of approximately 170 cows each: infected, all quarters treated (I-AT), or infected quarters treated only (I-QT). The new infection rate during the dry period was nearly 4 times higher for I-QT (15.3%) due to significantly more new infections by Staphylococcus aureus and Streptococcus uberis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Neurological diseases of ruminant livestock in Australia. III: bacterial and protozoal infections     

AE Kessell  JW Finnie  PA Windsor 《Australian veterinary journal》2011,89(8):289-296

Bacteria (including chlamydia) and protozoa can produce neurological disease in Australian ruminant livestock and the nature of the inflammatory and neuroparenchymal response is often suggestive of a particular aetiological agent. An overview of the clinicopathological features of infectious disease affecting the central nervous system (CNS) is followed by a discussion of important bacterial and protozoal infections in Australia. Each infectious disease is discussed in terms of classification and pathogenesis linked to clinical signs and gross and microscopic findings. The literature review is restricted to infectious conditions causing CNS disease in Australia. Sources include the Australian Veterinary Journal (over 50 years of articles), the quarterly newsletter of the National Animal Health Surveillance System and the Animal Health Surveillance Quarterly.  相似文献