Fish Pathology     

JD Humphrey 《Australian veterinary journal》2002,80(6):370-370

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Furazolidone toxicity in dairy calves     

JD TAYLOR  JA GIBSON  CEF YEATES 《Australian veterinary journal》1991,68(5):182-183

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Cardiomyopathy and woolly haircoat syndrome of Hereford cattle     

GJ STORIE  JA GIBSON  JD TAYLOR 《Australian veterinary journal》1991,68(3):119-119

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Estimating the mass of asteroid 253 mathilde from tracking data during the NEAR flyby   总被引：1，自引：0，他引：1  

DK Yeomans  J Barriot  DW Dunham  RW Farquhar  JD Giorgini  CE Helfrich  AS Konopliv  JV McAdams  JK Miller  WM Owen  DJ Scheeres  SP Synnott  BG Williams 《Science (New York, N.Y.)》1997,278(5346):2106-2109

The terminal navigation of the Near Earth Asteroid Rendezvous (NEAR) spacecraft during its close flyby of asteroid 253 Mathilde involved coordinated efforts to determine the heliocentric orbits of the spacecraft and Mathilde and then to determine the relative trajectory of the spacecraft with respect to Mathilde. The gravitational perturbation of Mathilde on the passing spacecraft was apparent in the spacecraft tracking data. As a result of the accurate targeting achieved, these data could be used to determine Mathilde's mass as 1.033 (+/- 0.044) x 10(20) grams. Coupled with a volume estimate provided by the NEAR imaging team, this mass suggests a low bulk density for Mathilde of 1.3 grams per cubic centimeter.  相似文献   

Testosterone serum profile,semen characteristics and testicular biometry of Mangalarga Marchador stallions in a tropical environment          下载免费PDF全文

B Waddington  JM Penitente‐Filho  JGS Neves  RO Pinho  AY Chaya  PP Maitan  CO Silveira  MG Neves  SEF Guimarães  GR de Carvalho  JD Guimarães 《Reproduction in domestic animals》2017,52(2):335-343

This study was conducted to characterize the daily profile of testosterone secretion and its mean concentrations in the four seasons as well as to evaluate the semen characteristics and testicular biometry of Mangalarga Marchador stallions throughout the year in a tropical region. Three stallions were submitted to semen collections and evaluation of testicular biometry every 14 days along a year. Blood samples were collected once at the middle of each season, in a 20‐min interval during 24 hr in order to evaluate the testosterone secretion profiles among seasons. Testosterone concentrations along the day were higher at the beginning of the afternoon (from 12:00 to 15:00 hr), but a circadian secretion was not clearly observed. Mean testosterone concentrations did not differ among seasons (p > .05), but a pattern of secretion along the day showed variations with higher concentrations in the afternoon during the winter. Ejaculate volume was higher during summer; however, sperm motility decreased in summer and spring. Total sperm in ejaculate, sperm morphology and testicular biometry kept constant along the year showing no differences among the seasons. The results demonstrated that in a tropical region, reproductive aspects of stallions did not show a clearly defined seasonal variation, and months of autumn and winter were not unsuitable for reproduction of the males.  相似文献   

Immotile Short‐Tail Sperm Defect in Nelore (Bos taurus indicus) Breed Bulls     

JB Siqueira  RO Pinho  SEF Guimarães  T Miranda Neto  JD Guimarães 《Reproduction in domestic animals》2010,45(6):1122-1125

This case study reported the presence of short tail sperm defect in the semen of three Nelore breed bulls. The sperm presented 0% of motility in the three animals evaluated and a total of 70%, 61% and 34% of pathologies of the intermediate piece of the tail respectively for animals 1, 2 and 3. It was identified that animals 2 and 3 had high degree of inbreeding, although no relationship was found with animal 1. Animal 2 was the only one that presented inbreeding coefficient (6.25%). His half‐sib (animal 3) and animal 1, from the same herd, had shown no inbreeding, showing that inheritance is not the only determinant factor for its incidence on Nelore males.  相似文献   

Effects of respacing on young Sitka spruce crops   总被引：1，自引：0，他引：1  

Deans  JD; Milne  R 《Forestry》1999,72(1):47-58

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Continental drainage in north america during the phanerozoic from Nd isotopes     

PJ Patchett  GM Ross  JD Gleason 《Science (New York, N.Y.)》1999,283(5402):671-673

Neodymium (Nd) isotopic data show consistent patterns in the sources of sedimentary rocks in North America at a continental scale. Between 600 and 450 million years ago (Ma), ancient continental shield sources dominated. Around 450 Ma, detritus from the Caledonian-Appalachian mountains overwhelmed sediment from all older sources, and is documented over large areas of the southern, western, and northern margins of North America. This material continued to dominate the sediment supply until about 150 Ma, probably due to cannibalistic recycling of sedimentary rocks formed earlier. Around 150 Ma, the rising western Cordillera delivered new and different detritus to the sedimentary system.  相似文献   

Testing for therapeutic medications: analytical/pharmacological relationships and 'limitations' on the sensitivity of testing for certain agents     

T Tobin  J D Harkins  R A Sams 《Journal of veterinary pharmacology and therapeutics》1999,22(3):220-233

Proper veterinary care of horses requires that horses in training have access to modern therapeutic medication. However, the sensitivity of equine drug testing now allows for detection of pharmacologically insignificant concentrations of many therapeutic medications. In 1995, the Association of Racing Commissioners International (ARCI) resolved that members 'address trace level detection so as not to lead to disciplinary action based on pharmacologically insignificant traces of these substances'. The rationale behind this approach is to prevent overly-sensitive testing from inhibiting the proper and appropriate veterinary care of performance horses. This review describes a scientific approach to implement this resolution using local anaesthetics as a model system and compares this approach with others currently in place. For the purpose of this discussion, a 'trace' concentration is defined as a pharmacologically-insignificant concentration. Initially, the target pharmacological effect (e.g. local anaesthesia) was identified, and the dose response relationship was quantified. The 'Highest No Effect Dose' (HNED) was estimated and then administered to horses. Next, the target analyte was identified, synthesized, if necessary, and quantified in blood or urine; the concentrations observed after administration of the HNED are, by definition, true concentrations and hence are pharmacologically insignificant. The key to this approach has been the synthesis of a unique series of authentic equine metabolite standards, which has allowed scientific identification of the concentration at which the pharmacological effect was indistinguishable from control values. Traces found at less than this concentration are, by definition, 'no effect limits', 'no effect traces' (NETs), 'no effect cut-offs', 'no effect limitations on the sensitivity of testing', or 'subtherapeutic residues'. Conversely, this approach will also identify potent medications for which the sensitivity of testing may need to be improved. Within the context of these experiments, the data create an analytical/pharmacological database that should assist industry professionals in interpreting the significance of trace concentrations of these medications or their metabolites in official samples. The most favourable outcome of this research is more medically appropriate use of therapeutic medications in performance horses, yielding substantial benefits to the health and welfare of these horses.  相似文献   

Pharmacokinetics of gentamicin in newborn to 30-day-old foals     

L E Cummings  A J Guthrie  J D Harkins  C R Short 《American journal of veterinary research》1990,51(12):1988-1992

Gentamicin sulfate, equivalent to 4 mg of gentamicin base/kg of body weight, was administered IV to 6 Thoroughbred foals on day 1 (12 to 24 hours of age) and at 5, 10, 15, and 30 days after birth. On day 40 after parturition, gentamicin was given to the mares at a dosage similar to that used in foals. Decay of serum gentamicin concentrations was best described by a 2-compartment model. Among foals, the overall elimination rate constant at 30 days of age was significantly (P less than 0.05) greater than at days 1, 10, and 15. There was, however, no difference in the overall elimination rate constant between foals and mares. The volume of distribution (Vd), determined on the basis of total area under the disposition curve, did not change between day 1 and day 30. Mean values of Vd of foals were between 1.5 and 2.5 times higher than the mean Vd of the mares; however, only values from the foals at days 5 and 10 were significantly greater. Both age and interindividual differences were reflected in the total body clearance (ClB) of gentamicin. Total body clearance of gentamicin of foals on day 1 was less than that of foals on days 5, 10, and 30. Additionally, C1B of gentamicin on day 15 was less than that on day 30. There was no significant difference between ClB of foals and mares except for the day-30 group, which had a higher clearance rate than did the adults. Protein binding of gentamicin was less than 30% in all groups, and there were no apparent age-related differences.  相似文献