Compositional heterogeneity in the bottom 1000 kilometers of Earth's mantle: toward a hybrid convection model     

van der Hilst RD  Karason H 《Science (New York, N.Y.)》1999,283(5409):1885-1888

Tomographic imaging indicates that slabs of subducted lithosphere can sink deep into Earth's lower mantle. The view that convective flow is stratified at 660-kilometer depth and preserves a relatively pristine lower mantle is therefore not tenable. However, a range of geophysical evidence indicates that compositionally distinct, hence convectively isolated, mantle domains may exist in the bottom 1000 kilometers of the mantle. Survival of these domains, which are perhaps related to local iron enrichment and silicate-to-oxide transformations, implies that mantle convection is more complex than envisaged by conventional end-member flow models.  相似文献   

Egtved virus: occurrence of inapparent infections with virulent virus in free-living rainbow trout, Salmo gairdneri Richardson, at low temperature     

P. E. VESTERGÅRD JØRGENSEN 《Journal of fish diseases》1982,5(3):251-255

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Can sheep become infected by grazing pasture contaminated by cattle with Johne's disease?     

D.R. Ris  K.L. Hamel  Jennifer M. Ayling 《New Zealand veterinary journal》2013,61(8)

Extract

Madam:- Transmission of Johne's disease (JD) under natural conditions from sheep to cattle has been demonstrated in iceland⁽²⁾ but not in New Zealand.⁽¹⁾ The reverse, sheep becoming infected with Mycobacterium paratuberculosis of bovine origin, has been shown experimentally with large inocula (c. 5 × 10⁹organisms/lamb),⁽³⁾ but not under natural conditions. It could be important in New Zealand where sheep may be used to “clean up” pasture grazed by paratuberculous cattle.  相似文献   

Cilia and cilia-related disorders     

AC Johnstone  SR McGlashan  RD Jolly 《New Zealand veterinary journal》2013,61(1)

Abstract

Extract

Among the puzzling aspects of the recently described autosomal recessive polycystic kidney disease (ARPKD) of sheep (Johnstone et al 2005 Johnstone, AC, Davidson, BI, Roe, AR, Eccles, MR and Jolly, RD. 2005. Congenital polycystic kidney disease in lambs. New Zealand Veterinary Journal, 53: 307–314. [Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]) is the multiplicity of organ systems affected and the phenotypic variations that occur between the various animal species. It has been shown in studies of other inherited polycystic kidney disease syndromes that the normal gene products of a mutant are likely to be involved in ciliary structure and function. The studies that have led to this recognition can be expected to eventually provide the basis for a better understanding of the functioning of this organelle, and the pathogenesis of lesions in the related diseases.

It is well known that cilia are important in the perception of light, olfactory stimuli and sound and that motile cilia provide cell motility (e.g. sperm) and transport of mucus and other fluids. Recent research has indicated that the involvement of the primary cili-um/basal body complex is of central importance in the detection and cellular response to extracellular movement of fluid, critical phases of embryonic development, cell cycle regulation and maintenance of cell polarity.

Confocal microscopic studies of renal cyst epithelium in ovine ARPKD have shown that only 30% of cells have a cilium and that these are often truncated (McGlashan et al 2005 McGlashan, SR, Poole, CA, Stayner, C, Johnstone, AC, Eccles, MR and Jensen, CG. 2005. “Primary cilia in fibrosis associated with two models of polycystic kidney disease”. In Proceedings of the 45th Annual Conference of the American Society for Cell Biology December 10–14 [Google Scholar]). The observation, although preliminary, strongly supports the argument that the mutant gene in this disease of sheep normally encodes for a protein essential for primary ciliary function.  相似文献   

Laboratory diagnosis of Mycoplasma/Ureaplasma abortion in cattle     

Watson P  Mason C  Stevenson H  Scholes S  Schock A  Mearns R  Ayling R  Nicholas R 《The Veterinary record》2012,170(3):82-84

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Comparison of complement fixation test,immunoblotting, indirect ELISA,and competitive ELISA for detecting antibodies to Mycoplasma mycoides subspecies mycoides small colony (SC) in naturally infected cattle from the 1995 outbreak in Botswana     

Marobela-Raborokgwe C  Nicholas R  Ayling R  Bashiruddin JB 《The Onderstepoort journal of veterinary research》2003,70(1):21-27

Four serological tests were compared in order to evaluate their efficacies in detecting antibodies to M. mycoides subspecies mycoides SC in cattle sera sampled in 1995 from herds affected with contagious bovine pleuropneumonia (CBPP) in the north-western part of Botswana. Tests that were compared included immunoblotting test (IBT), indirect enzyme-linked immunosorbent assay (i-ELISA), competitive enzyme-linked immunosorbent assay (c-ELISA) and complement fixation test (CFT). The percentages of seropositive samples in the iELISA (48%) and in the c-ELISA (48%) were similar but were comparatively lower than those obtained by the IBT (57%) and CFT (61%). The percentages of positive sera in the IBT and CFT were also similar and overall the efficacy of these tests was better than that of the two ELISA tests. There was 95.5% agreement between the IBT and CFT, 85% agreement between the IBT and c-ELISA, 90.9% agreement between the IBT and i-ELISA, 88.6% agreement between the i-ELISA and CFT, 80% agreement between the c-ELISA and CFT and 90% agreement between the two ELISA tests. It became clearly evident from this comparative study that no single serological test was capable of detecting all animals affected by CBPP under natural field conditions of infection.  相似文献   

Identification and differentiation of European and African/Australian strains of Mycoplasma mycoides subspecies mycoides small-colony type using polymerase chain reaction analysis.     

Katie Miles  Colin P Churchward  Laura McAuliffe  Roger D Ayling  Robin A J Nicholas 《Journal of veterinary diagnostic investigation》2006,18(2):168-171

Mycoplasma mycoides subspecies mycoides small-colony type (M. m. m. SC) is the cause of the economically important contagious bovine pleuropneumonia. Isolates from Africa and Australia have previously been documented to have a fragment of approximately 8.84 kb, which is absent in European strains. A set of polymerase chain reaction (PCR) primers over this region was designed to identify M. m. m. SC isolates and separate European strains from those of Africa/Australia. Specificity of the PCR assay was achieved through the positioning of an oligonucleotide within the insertion sequence IS1296, upstream of this deletion, which then was paired with a reverse primer, upstream of the deletion, within the 8.84 kb-deleted region or downstream of the deletion, generating fragments of 1.1 kb (all M. m. m. SC strains), 1.4 kb (African/Australian strains only) and 1.3 kb (European strains only), respectively. Identification and differentiation was specific for DNA from M. m. m. SC with no amplification of DNA from other cluster members or closely related species. The PCR products did not require differentiation by use of a restriction endonuclease, and have potential for use in detection of this organism in clinical samples.  相似文献   

Porcine Conceptus Oct-4 mRNA Expression During Peri-implantation Development     

DS Spencer  JW Ross  MD Ashworth  RD Geisert  LF Rickords 《Reproduction in domestic animals》2006,41(6):571-572

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Application of an indirect ELISA to milk samples to identify cows with Mycoplasma bovis mastitis   总被引：1，自引：0，他引：1  

Byrne WJ  Ball HJ  Brice N  McCormack R  Baker SE  Ayling RD  Nicholas RA 《The Veterinary record》2000,146(13):368-369

An indirect ELISA was used to detect antibodies to Mycoplasma bovis in milk samples collected from a herd with M bovis mastitis. Antibodies were detected in samples from nine cows which had developed clinical M bovis mastitis. Milk from only three consistently antigen-negative cows tested positive for M bovis antibodies. These results indicate the potential value of the indirect ELISA for the detection of cows which have recently developed M bovis mastitis during the early stages of an outbreak.  相似文献   

Rundschau     

Leib RD i. R. Dr Edmund 《Journal of pest science》1989,62(4):74-76

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