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31.
Ninety-nine multiparous Brahman-influenced (1/4 to 3/8 Brahman) cows were managed to achieve low (BCS = 4.3 +/- 0.1; n = 50) or moderate (BCS = 6.1 +/- 0.1; n = 49) body condition (BC) to determine the influence of bovine somatotropin (bST) on estrous characteristics, reproductive performance, and concentrations of serum GH and plasma NEFA. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg s.c.) on d -35, -21, and -7 before initiation of the breeding season. On d -7, all cows received an intravaginal, controlled internal drug-releasing (CIDR) device. On d 0 (initiation of the 70-d breeding season), the CIDR were removed and cows received prostaglandin F2alpha (PGF2alpha). Blood samples were collected from the median caudal vein of the cows at each bST treatment and at d -28 and 0. Estrous behavior was monitored by radiotelemetry during the first 30 d of the breeding season. Growth hormone was increased (P < 0.05) in low and moderate BC cows treated with bST. The percentage of cows detected in estrus during the first 30 d of the breeding season was decreased (P = 0.05) for low BC (64%) compared with moderate BC (82%) cows. The interval to first estrus tended (P = 0.07) to be shorter in low BC-bST-treated cows (3.7 +/- 1.9 d) than in moderate BC-bST-treated cows (9.6 +/- 1.8 d). During the first 30 d of the breeding season, cows in low BC had a decreased (P = 0.02) number of mounts received and increased (P = 0.001) quiescence between mounts compared with cows in moderate BC. The number of mounts received was reduced (P = 0.04) in bST-treated cows. More (P = 0.02) cows treated with bST became pregnant during the first 3 d of the breeding season compared with non-bST-treated cows. The cumulative first-service conception rate tended (P = 0.07) to be greater for bST-low BC cows than non-bST-treated cows in low or moderate BC. On d 0, NEFA were greater (P < 0.05) in bST-treated vs. non-bST-treated cows. Low BC and bST reduced the intensity of behavioral estrus in postpartum Brahman-influenced cows. However, bST increased the first-service conception rate during the first 30 d of breeding and pregnancy rates during the first 3 d of breeding in postpartum Brahman-influenced cows.  相似文献   
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Direct measurements of the current-phase relation, I versus Deltaphi, for a weak link coupling two reservoirs of B-phase superfluid helium-3 (3He-B) were made over a wide range of temperatures. The weak link consists of a square array of 100-nanometer-diameter apertures. For temperatures T such that T/Tc >/= 0.6 (where Tc is the superfluid transition temperature), I approximately sin(Deltaphi). At lower temperatures, I(Deltaphi) approaches a straight line. Several remarkable phenomena heretofore inaccessible to superconducting Josephson junctions, including direct observation of quantum oscillations and continuous knowledge of Deltaphi, were also observed.  相似文献   
35.
Lamb RC  Weekes TC 《Science (New York, N.Y.)》1987,238(4833):1528-1534
One of the major astronomical discoveries of the last two decades was the detection of luminous x-ray binary star systems in which gravitational energy from accretion is released by the emission of x-ray photons, which have energies in the range of 0.1 to 10 kiloelectron volts. Recent observations have shown that some of these binary sources also emit photons in the energy range of 10(12) electron volts and above. Such sources contain a rotating neutron star that is accreting matter from a companion. Techniques to detect such radiation are ground-based, simple, and inexpensive. Four binary sources (Hercules X-1, 4U0115+63, Vela X-1, and Cygnus X-3) have been observed by at least two independent groups. Although the discovery of such very high energy "gamma-ray binaries" was not theoretically anticipated, models have now been proposed that attempt to explain the behavior of one or more of the sources. The implications of these observations is that a significant portion of the more energetic cosmic rays observed on Earth may arise from the action of similar sources within the galaxy during the past few million years.  相似文献   
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Ultrasound-guided catheter biopsy of lesions affecting the lower urinary tract was attempted in 12 dogs with mucosal lesions affecting the bladder [nine] or urethra (three). Histological biopsies were obtained by catheter biopsy in 10 dogs, enabling diagnosis of transitional cell carcinoma in five, papilloma in two, prostatic carcinoma in two and chronic cystitis in one. Cytological samples alone were obtained in two dogs, one of which enabled a diagnosis of transitional cell carcinoma; the other contained evidence of haemorrhage and inflammation, but squamous cell carcinoma was found in a subsequent exci-sional biopsy. Intravesicular haemorrhage after biopsy was observed ultrasonographically in two dogs. Ultrasound guidance enables accurate determination of biopsy catheter position. The size of biopsies obtained by this method may limit the accuracy of histological diagnosis.  相似文献   
37.
Ultrasonography is an important diagnostic technique in veterinary medicine. It may be used to examine most structures in the small animal ahdomen, providing a rapid, non-invasive means of supplementing information obtained by physical examination and radiography. Limitations of ultrasonography include the non-specific nature of many observed abnormalities, which prevents a specific diagnosis, and the difficulty of identifying certain normal organs such as the pancreas. This paper reviews ultrasonography of the liver, spleen and pancreas, and ultrasound-guided biopsy in small animals, and indicates areas of potential future development.  相似文献   
38.
To assess the diagnostic accuracy of survey radiography for canine thoracolumbar intervertebral disc protrusion, survey radiographs (lateral and ventrodorsal) of 64 dogs with surgically-confirmed thoracolumbar intervertebral disc protrusion, 51 dogs with negative myelograms and 29 dogs with various spinal conditions other than disc protrusion were reviewed by three independent observers who were unaware of any clinical information. There were marked differences in observer performance for diagnosis of intervertebral disc protrusion, although there were no significant differences in intraobserver diagnostic accuracy for small vs. large dogs. Accuracy of observers for determining sites of intervertebral disc protrusion using survey radiography was in the range 51-61%. All observers had low accuracy for identification of second sites of intervertebral disc protrusion. The most useful radiographic sign, narrowed intervertebral space, had only moderate sensitivity (range 64-69%) and moderate predictive value (range 63-71%) for intervertebral disc protrusion. Vacuum phenomenon was an infrequent but accurate sign of intervertebral disc protrusion. Recognition of multiple radiographic signs of intervertebral disc protrusion at one site was associated with increased accuracy of diagnosis. No observer was accurate enough to justify attempting targeted surgical treatment of intervertebral disc protrusion without myelography.  相似文献   
39.
The ultrasonographic features of paraprostatic cysts in nine dogs are described along with historical, clinical, surgical and pathologic findings. Cysts occurred predominantly in older, large breed dogs (mean age 8 years, range 3–11 years). The most common presenting complaints were depression, inappetance, stranguria, tenesmus and bloody penile discharge. A palpable abdominal mass was the most common physical finding. Ultrasonographically, paraprostatic cysts were usually large anechoic structures; many contained internal septa. Moderately large anechoic cavities or cysts were also detected in the prostatic parenchyma of five dogs, and in two of these communication with the paraprostatic cyst was visualized. There were no clearly distinct ultrasonographic criteria to discriminate septic from nonseptic paraprostatic cysts.  相似文献   
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