Anthropogenic and meteorological factors influence vector abundance and prevalence of bluetongue virus infection of dairy cattle in California     

Mayo CE  Gardner IA  Mullens BA  Barker CM  Gerry AC  Guthrie AJ  MacLachlan NJ 《Veterinary microbiology》2012,155(2-4):158-164

Bluetongue is an economically important arboviral disease of ruminants that is transmitted by hematophagous Culicoides midges. In light of dramatic recent changes in the global distribution of bluetongue virus (BTV), the goals of this study were to re-evaluate the prevalence of BTV infection of cattle and abundance of Culicoides midges on individual dairy farms in California. A serosurvey of adult dairy cattle confirmed that BTV infection is prevalent throughout much of the state, although the coastal northwestern region remains free of infection and prevalence varies markedly among farms in the remainder of the state. Intensive sampling for one year of 4 farms in the northern Central Valley of California showed that the abundance of Culicoides midges was markedly different and coincided with the prevalence of BTV infection of sentinel cattle on each farm. Mean maximum and minimum temperatures and other meteorological parameters were similar on all 4 farms, thus we speculate that particular management practices were responsible for both the increased midge abundance and prevalence of BTV infection of cattle at individual farms. Specifically, it is concluded that variation in vector abundance at individual farms most likely is the result of waste-water lagoon and irrigation management practices, leading to higher BTV infection rates among livestock held on farms with more waste-water lagoons and greater acreage of land for waste-water irrigation.  相似文献   

Binding of insecticides to macromolecules in the blood of the rat and American cockroach     

H.L. Skalsky  F.E. Guthrie 《Pesticide biochemistry and physiology》1975,5(1):27-34

This investigation concerns transport of DDT, dieldrin and parathion in the blood of the rat and roach. Using gel filtration, ion-exchange chromatography, and disc gel electrophoresis, a method for the isolation of some of the plasma proteins that bind DDT and dieldrin has been demonstrated. By a variety of staining procedures, these macromolecules were shown to be of a lipoprotein nature. A tentative molecular weight of 520,000 was obtained for one of the binding proteins in roach hemolymph.  相似文献   

Lateral transmission of equine arteritis virus among Lipizzaner stallions in South Africa     

Guthrie AJ  Howell PG  Hedges JF  Bosman AM  Balasuriya UB  McCollum WH  Timoney PJ  MacLachlan NJ 《Equine veterinary journal》2003,35(6):596-600

REASONS FOR PERFORMING STUDY: A serological study conducted in 1995 revealed that 7 stallions at the Lipizzaner Centre, Gauteng, South Africa, were seropositive for antibody to equine arteritis virus (EAV). A Lipizzaner stallion imported into South Africa from Yugoslavia in 1981 had previously (1988) been confirmed to be an EAV carrier. Despite being placed under life-long breeding quarantine, EAV had been transmitted between stallions at the Lipizzaner Centre. OBJECTIVES: To investigate the phylogenetic relationships between the strain of EAV shed in the semen of the original carrier stallion and strains recovered from the semen of 5 other stallions; and to investigate the means whereby lateral transmission of EAV occurred among 7 in-contact, nonbreeding stallions at the Centre. METHODS: EAV was isolated from semen collected from the seropositive stallions using RK-13 cells. Viral RNA was reverse transcribed and amplified by polymerase chain reaction using ORF 5-specific primers, subjected to sequence and phylogenetic analysis. RESULTS: Phylogenetic analysis of strains of EAV recovered from the semen of 6 persistently infected stallions confirmed that all viruses were closely related and probably derived from a common ancestor, i.e. the stallion imported from Yugoslavia. Lateral transmission subsequently occurred among 7 in-contact, nonbreeding stallions at the Centre. It is speculated that these stallions may have been exposed to virus from bedding or fomites contaminated with semen. CONCLUSIONS: These data confirm that lateral transmission of EAV can occur from shedding stallions to susceptible, in-contact horses, including other stallions, which may become persistently infected with the virus. POTENTIAL RELEVANCE: The findings are consistent with lateral spread of a single, unique strain of EAV among a group; and suggest that transmission of EAV may be initiated by infection of one or more stallions with virus on bedding or other fomites contaminated with EAV- infected semen.  相似文献   

Pesticides in aquatic environments: Mohammed Abdul Quddus Khan,Ed. No. 10 in Environmental Science Research. Plenum Press,New York and London, 1978. 257 pp., $29.50     

Frank E. Guthrie 《Pesticide biochemistry and physiology》1978,9(3):352

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Sum rules and interlayer conductivity of high-Tc cuprates     

DN Basov  SI Woods  AS Katz  EJ Singley  RC Dynes  M Xu  DG Hinks  CC Homes  M Strongin 《Science (New York, N.Y.)》1999,283(5398):49-52

Analysis of the interlayer infrared conductivity of cuprate high-transition temperature superconductors reveals an anomalously large energy scale extending up to midinfrared frequencies that can be attributed to formation of the superconducting condensate. This unusual effect is observed in a va- riety of materials, including Tl2Ba2CuO6+x, La2-xSrxCuO4, and YBa2Cu3O6.6, which show an incoherent interlayer response in the normal state. Midinfrared range condensation was examined in the context of sum rules that can be formulated for the complex conductivity. One possible interpretation of these experiments is in terms of a kinetic energy change associated with the superconducting transition.  相似文献   

River rehabilitation in an urban environment: examples from the Mersey Basin,North West England     

P.A. Nolan  N. Guthrie 《水产资源保护:海洋与淡水生态系统》1998,8(5):685-700

1. The River Mersey is one of the most polluted and heavily engineered watercourses in Europe. Improvements in water quality have led to the re-establishment of fish populations in parts of the catchment. Further improvements in the water quality of the Mersey Basin are planned. The Environment Agency is building on these water quality improvements by improving the physical structure of watercourses and their corridors as part of catchment-wide community-driven initiatives. 2. Two examples are given. Whittle Brook, a small lowland watercourse, was unusual in that the highly engineered and managed stream ran through an area of landscaped ‘green space’ in a modern housing development. The physical structures of the stream and its riparian zone have been restored as an integral feature of its local landscape. The River Alt is a medium-sized lowland watercourse that has been heavily ‘channelized’ in the past. As part of a community-driven catchment plan called ‘Alt 2000’, a culverted section of the river has been restored to an open river corridor designed to create a range of riparian habitats with associated planting. 3. The paper illustrates a multi-functional approach used in urban river rehabilitation and concludes that the involvement of multi-functional teams with the local community is the key to success. © 1998 John Wiley & Sons, Ltd.  相似文献   

DUODENAL ULTRASONOGRAPHY IN THE NORMAL ADULT HORSE   总被引：1，自引：0，他引：1  

Robert M.  Kirberger  MMedVet  Jacobus S. van den  Berg  MMedVet  Roy D.  Gottschalk  MMedVet  Alan J.  Guthrie  MMedVet PhD 《Veterinary radiology & ultrasound》1995,36(1):50-56

Ultrasonography was used to evaluate the duodenum of 6 clinically normal horses. Examinations were performed in horses which each, alternatively, received diets of; 1) concentrates and hay, 2) hay only, or 3) after 36 hours of starvation. The duodenum was constantly visualized just ventral to the right kidney at the 16th and 17th intercostal spaces on a line joining the olecranon and tuber sacrale. Cranial to the 16th intercostal space visibility depended on thickness of interposing liver and lung field interference. Duodenal distensions, contractions and content are described. Starved horses had fewer contractions and distensions than horses on hay, or hay and concentrate diets but the difference was not significant. Duodenal wall thickness ranged from 3–4 mm. Ultrasonographically five layers, corresponding to the mucosal surface, mucosa, submucosa, muscularis propria and serosa, could be identified. A necropsy specimen of the duodenum was evaluated histologically and Ultrasonographically in a water bath for comparison.  相似文献   

RADIOLOGY CORNER     

Christopher R.  Lamb  MA  VetMB  Sue  Guthrie  BVetMed  PhD 《Veterinary radiology & ultrasound》1995,36(5):383-383

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The geographic distribution of hydatid infection in cattle in Western Australia Western Australia     

AJ LYMBERY  RCA THOMPSON  CC CONSTANTINE  JG KRUGER 《Australian veterinary journal》1995,72(11):430-432

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Changes in plasma follicle-stimulating hormone, luteinizing hormone, estrogen and progesterone during growth of ovulatory follicles in the pig     

H D Guthrie  D J Bolt 《Domestic animal endocrinology》1990,7(1):83-91

This experiment was conducted to determine the changes in secretion of LH, FSH, estrogen and progesterone during follicle maturation. Ovaries were recovered from 11 non-treated (control) gilts, three on day 13, four on day 16, and four on day 19 of the estrous cycle, and from four altrenogest-treated gilts on day 19. Altrenogest, a progesterone agonist, was fed at a dose of 20 mg once daily from days 13 to 18 to block spontaneous follicle maturation. Gilts were bled daily from day 12 until slaughter. For control gilts, the number of follicles/gilt 1-6 mm in diameter decreased (P less than .05) from 93.5 on day 13 to 21.5 on day 19, and the number of large (greater than 6 mm) follicles increased (P less than .05) from 5.3 to 13.2. Altrenogest treatment blocked loss of small follicles and growth of large follicles between days 13 and 19. Plasma progesterone decreased (P less than .001) between days 12 and 16 in both control and altrenogest-treated gilts. Plasma FSH decreased (P less than .05) between days 12 and 16 only in control gilts. Plasma LH was not significantly affected by day or altrenogest treatment. Plasma estrogen increased (P less than .05) between days 15 and 19 only in control gilts. These results indicate that 1) no increased LH secretion was detected in conjunction with emergence of ovulatory follicles, and 2) atresia of nonovulatory follicles was associated with decreased secretion of FSH. Both atresia and decreasing FSH secretion began before estrogen concentration increased in the systemic circulation.  相似文献