A Comparison of Methods for Deriving Solute Flux Rates Using Long-Term Data from Streams in the Mirror Lake Watershed     

Bukaveckas  P.A.  Likens  G.E.  Winter  T.C.  Buso  D.C. 《Water, air, and soil pollution》1998,105(1-2):277-293

Calculation of chemical flux rates for streams requires integration of continuous measurements of discharge with discrete measurements of solute concentrations. We compared two commonly used methods for interpolating chemistry data (time-averaging and flow-weighting) to determine whether discrepancies between the two methods were large relative to other sources of error in estimating flux rates. Flux rates of dissolved Si and SO₄ ^2- were calculated from 10 years of data (1981^-1990) for the NW inlet and outlet of Mirror Lake and for a 40-day period (March 22 to April 30, 1993) during which we augmented our routine (weekly) chemical monitoring with collection of daily samples. The time-averaging method yielded higher estimates of solute flux during high-flow periods if no chemistry samples were collected correponding to peak discharge. Concentration-discharge relationships should be used to interpolate stream chemistry during changing flow conditions if chemical changes are large. Caution should be used in choosing the appropriate time-scale over which data are pooled to derive the concentration-discharge regressions because the model parameters (slope and intercept) were found to be sensitive to seasonal and inter-annual variation. Both methods approximated solute flux to within 2^-10% for a range of solutes that were monitored during the intensive sampling period. Our results suggest that errors arising from interpolation of stream chemistry data are small compared with other sources of error in developing watershed mass balances.  相似文献   

Observations on the genital tract of cull ewes.     

A C Winter  H Dobson 《The Veterinary record》1992,130(4):68-70

Genital tracts were collected from non-pregnant cull ewes in early April and examined for macroscopic abnormalities. An assessment was made of the possible effect of any abnormality on the ability of the animal to become pregnant. It was found that 23.2 per cent of the tracts had abnormalities and it was considered that 16.8 per cent had abnormalities likely to interfere with the establishment of pregnancy.  相似文献   

Comparison of the Johne''s absorbed EIA and the complement-fixation test for the diagnosis of Johne''s disease in cattle   总被引：2，自引：0，他引：2  

SE RIDGE  IR MORGAN  DC SOCKETT†  MT COLLINS†  RJ CONDRON  NW SKILBECK†  JJ WEBBER§ 《Australian veterinary journal》1991,68(8):253-257

A commercially available absorbed ELISA for the diagnosis of Johne's disease (JD) (paratuberculosis) in cattle, the Johne's Absorbed EIA, was compared with the conventional complement-fixation test (CFT) used in Australia. Stored plasma from 3 Victorian dairy herds with a history of JD, sera from specimens submitted from animals showing clinical signs of JD and sera from the US National Repository for Paratuberculosis Specimens were used to determine the sensitivity of each test. The EIA detected 48.8% of 43 Australian animals with subclinical JD, while the CFT detected only 12 (21.4%) of 56 subclinically affected cattle. Of 150 subclinically infected US cattle, the EIA detected 47.3% and the CFT detected 52.0%. The EIA detected 59.7% of animals which at the time of sampling were shedding Mycobacterium paratuberculosis in their faeces, but showed no clinical signs of JD, while the CFT detected 57.3%. The EIA correctly identified 88.2% of 136 histologically confirmed clinical cases, and the CFT detected 83.4%. The specificity of each test was determined by testing sera collected at slaughter from animals residing in a known JD-free area of Australia, and from samples from the US National Repository of Paratuberculosis Specimens collected from certified-free herds in Wisconsin. The EIA was found to have a specificity of 99.8% when 998 Australian animals were used as the test population, and 99.0% when 196 US animals were used. The specificity of the CFT using Australian samples was 96.9% and 95.2% using American samples.  相似文献   

Mithun cross siri hybrids: cyto- and immunogenetic examinations and characterisation of abnormal spermatogenesis     

H Winter  M Kalat  B Mayr  E Dworak  W Schleger 《Research in veterinary science》1988,45(1):86-100

Cytogenetic studies of the mithun (Bos frontalis), the siri (Bos indicus) and their hybrids, as well as histological examinations of testes and epididymis of siri and hybrids were undertaken to throw further light on male hybrid infertility and interspecies incompatibility, in order to facilitate the possible development of a stable interspecies crossbreed which would be similar to the highly profitable jatsum, the female mithun cross siri hybrid. In both species there are distinct centromeric heteromorphisms which should provide a rich source of genetic markers for tracing chromosomes in controlled hybrid programmes. The nucleolar organisers in the F1 hybrids were derived from both parents, in contrast to other interspecies hybrids where the nucleolar organisers of one species tend to be suppressed by the other. This indicates a relatively close relationship between mithun and siri and supports the prospect of success for developing a stable crossbreed. Transferrins which may also be a useful source of genetic markers were identified and differences between siris and mithuns noted, especially in the D-bands. No A-bands were found in the siris and no E-bands in the mithuns. Whether this is a breed or species characteristic will have to be confirmed by examination of more animals. The findings on blood groups and haemoglobins, including differences between the two species, were similar to results obtained previously. In meiosis the sex vesicles were intact which indicates that infertility and incompatibility factors should be located in autosomes. In cytogenetic and histological examinations the testes of the siris were comparable to those of European cattle, while in all hybrids spermatogenetic activity was deficient although there were great differences between and within generations. While the exact mechanism of this diversity is not known at this stage, it should make it possible to select for increased male hybrid fertility which would be a prerequisite for developing a stable interspecies crossbreed. This selection would be facilitated by correlating infertility and incompatibility with genetic profiles and markers. A mithun cross siri crossbreed would also serve as a model for other interspecies breeding.  相似文献   

Interferon and 2',5'-oligo(A) synthetase activities in serum and blood mononuclear leukocytes of cattle after injection of bovine interferon-alpha 1.     

L J Perino  E C Short  L J Burge  D A Winter  R W Fulton 《American journal of veterinary research》1990,51(6):886-892

Cell extracts that were prepared from blood mononuclear leukocytes from 66 samples obtained from 6 clinically normal calves contained mean 2',5'-oligoadenylate (2',5'-oligo[A]) synthetase activity sufficient to synthesize 186 +/- 82 pmol of 2',5'-oligo(A)/h/10(6) cells. Calves had no measurable serum interferon (IFN) activity. Five calves were given IM injections of 10(4), 10(5), 5 x 10(5), 10(6), and 10(7) U of bovine IFN-alpha 1/kg of body weight at 2-week intervals. Five dosing sequences were used with a 5 x 5 Latin square design so that each calf received each dose once. Activity of 2',5'-oligo(A) synthetase increased at 24 hours in response to all dosages of IFN and then declined following first-order kinetics, with an apparent half-life (t1/2) of 2.1 +/- 0.5 days. The area under the concentration-time curve for 2',5'-oligo(A) synthetase increased with dose of IFN more rapidly than did peak response. Serum IFN that was measured at 1-day intervals following administration of IFN was consistently measurable only at dosages above 10(6) U of IFN/kg. The t1/2 for circulating IFN was 12.4 +/- 1.0 hours. Over all dosages, increases in 2',5'-oligo(A) synthetase activity were measurable for 3.5 days longer than were increases in IFN following IM injection of IFN. None of the calves developed detectable anti-IFN antibodies.  相似文献   

Restriction endonuclease analysis of Leptospira interrogans serovar hardjo isolates from cattle   总被引：3，自引：0，他引：3  

W A Ellis  A B Thiermann  J Montgomery  A Handsaker  P J Winter  R B Marshall 《Research in veterinary science》1988,44(3):375-379

The genomes of 253 strains of Leptospira interrogans serovar hardjo were examined by restriction endonuclease analysis of their DNA. The strains had been isolated from cattle at an abattoir (190), milk of agalactic cows (seven) and from aborted bovine fetuses (56). Two distinct genome types, Hardjoprajitno and Hardjobovis, were detected. The majority (91 per cent) of isolates from abattoir cattle were of the Hardjobovis type while most (76 per cent) of the isolates from clinical/pathological material were similar to Hardjoprajitno.  相似文献   

Attitudes of veterinarians to undergraduate education in genetics and the use of genetics in veterinary occupations     

CM WADE  DC FENWICK 《Australian veterinary journal》1996,73(1):1-5

A questionnaire regarding attitudes to undergraduate education in genetics and the subsequent use of that education was sent to 1000 veterinarians registered in New South Wales. Three hundred replies to the questionnaire were received and analysed. No significant difference in the perceived adequacy of courses at the four universities involved in teaching veterinary science was observed. Opinions on adequacy of education in genetics were not affected by age, sex or years since graduation. The major reason cited for lack of adequacy was that undergraduate genetics courses were not practical. Only 17 respondents stated that they were never approached for information on genetics or animal breeding, while 76 were approached more than 20 times annually for information. Eighty-three respondents claimed to deal with more than 20 cases annually that required some knowledge of genetics. The results of the questionnaire highlight the importance of genetics instruction in undergraduate veterinary education. The questionnaire responses also provide insight into how working veterinarians consider that courses in genetics could be improved.  相似文献   

The Establishment of Early Pregnancy in Cows     

DC Wathes  RS Robinson  GE Mann  GE Lamming 《Reproduction in domestic animals》1998,33(3-4):279-284

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Subspecies differentiation of Moraxella bovis by restriction endonuclease DNA analysis (BRENDA)     

Marshall RB  Winter PJ  Cooper BS  Robinson AJ 《New Zealand veterinary journal》1985,33(5):67-70

A total of 94 strains of Moraxella bovis have been examined by bacterial restriction endonuclease DNA analysis (BRENDA). These strains comprised isolates from the U.S.A., the U.K., in Australia, and from a number of widely separated areas within New Zealand. The strains were classified into a total of 26 different types on the basis of their BRENDA patterns. Fourteen types were present among 34 strains from the U.S.A., eight types from 17 strains in the U.K. three types from five strains in Australia but only one type resulted from all 38 New Zealand strains. Moraxella liquifaciens, M. nonliquifaciens and an atypical Moraxella sp. isolated from cattle eyes in Australia were tested and produced BRENDA patterns clearly different from those of the Moraxella bovis strains. BRENDA, when used with the restriction endonuclease EcoR1, did not provide a means of distinguishing between avirulent, nonhaemolytic M.bovis, and the virulent haemolytic strains.  相似文献   

Cystoscopy in cattle--a valuable additional tool for clinical examination     

Franz S  Winter P  Baumgartner W 《Acta veterinaria Hungarica》2004,52(4):423-438

Based on the findings of physical examination and on laboratory findings the urinary bladder of 23 cows was examined endoscopically in order to investigate the application of cystoscopy in cattle. The endoscopic findings of all examined cows were compared with the findings of physical examination and the results of macroscopic and microscopic urinalysis and the bacteriological culture of the urine. By physical examination only 3 cows were diagnosed to have urinary tract disease, whereas all other cows were suspected of having an urinary tract disease. Bacteriological culture of the urine revealed Corynebacterium renale and Escherichia coli infection in 18 cows, while the remaining 5 cows were negative. By cystoscopy catarrhal cystitis was diagnosed in 2 cases, haemorrhagic cystitis in 5 cases, and fibrinous-purulent and fibrinous-haemorrhagic cystitis in 13 cases. Three cows showed no pathological changes of the urinary bladder mucosa by endoscopic examination. Cystoscopy facilitates diagnosis through the direct visualisation of mucosal lesions and makes it possible to give a more accurate prognosis based upon the findings.  相似文献