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41.
Ovarian follicular growth in non‐mated llamas occurs in successive waves that generally superimpose their origin on the regression of the preceding wave (overlapping), originating prolonged sexual receptivity in the species. The aim of this study was to perform an ultrasonographic and endocrine characterization of individual and successive waves in non‐mated llamas with a special interest on the overlapping phenomenon. Twelve llamas were examined daily by transrectal ultrasonography for at least two consecutive waves. In six females, blood samples were collected daily at the end of each examination. The development of the largest follicle (F) showed a wavelike pattern with a mean duration of 25 days. All waves evaluated were partially overlapped on the preceding wave and emerged at a mean interval of 15.8 ± 0.5 days. This interwave interval determines a mean overlapping degree of 32% of the wave length. Similarly, mean plasma oestradiol‐17β (E2) concentrations followed a wavelike pattern. However, E2 concentrations started to decline before the structural regression of the F was observed. Mean basal E2 concentrations remain higher than 10.9 ± 0.6 pmol/l. In conclusion, follicular activity in non‐mated llamas is characterized by continuous emergence of successive waves that always overlap the preceding wave with variable degrees. E2 production during the follicular wave is shorter in duration than the morphological development of the F. Finally, the overlapping phenomenon maintains increased plasma E2 concentrations persistently and this could explain the prolonged periods of sexual receptivity registered in llamas. 相似文献
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Leandro Maia Maria Vernica de Souza MV MS DS Raphael Bragana Alves Fernandes BS MS DS Maurício Paulo Ferreira Fontes BS MS PhD Matheus Werner de Souza Vianna Walcrisley Vercelli Luz BS MS 《Journal of Equine Veterinary Science》2006,26(12):578-583
Pollution is a subject of worldwide concern and discussion and various areas of science are seeking to integrate their knowledge in an attempt to improve understanding of the harmful effects of modern human activities. Thus, the objective of the current study was to assess the potential for using the horse as a bio-indicator of environmental pollution. Blood and serum samples from 120 horses from locations with different degrees of urbanization and industrialization and the feeds used for these animals were analyzed to determine their heavy metal (Cd, Pb, Ni, Cu, and Zn) content. The data obtained were compared. The results did not show increases in heavy metal concentration in the blood and serum of the horses with the intensification of urbanization and industrialization around the farms. Only Cd, as determined in the blood of the animals, showed a certain potential for using horses as bio-indicators of environmental pollution. The data for sex, age, and chemical composition of the foodstuffs supplied to the animals were not determinants in explaining the variation in the concentrations of heavy metals observed. 相似文献
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G Blumberg M Kang MV Klein K Kadowaki C Kendziora 《Science (New York, N.Y.)》1997,278(5342):1427-1432
Electronic Raman scattering from high- and low-energy excitations was studied as a function of temperature, extent of hole doping, and energy of the incident photons in Bi2Sr2CaCu2O8+/-delta superconductors. For underdoped superconductors, short-range antiferromagnetic (AF) correlations were found to persist with hole doping, and doped single holes were found to be incoherent in the AF environment. Above the superconducting (SC) transition temperature Tc, the system exhibited a sharp Raman resonance of B1g symmetry and energy of 75 millielectron-volts and a pseudogap for electron-hole excitations below 75 millielectron-volts, a manifestation of a partially coherent state forming from doped incoherent quasi particles. The occupancy of the coherent state increases with cooling until phase ordering at Tc produces a global SC state. 相似文献
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Marco A.F. Lopes MV MS PhD Kenneth E. Sullins DVM MS Brettania L. Walker MPH 《Journal of Equine Veterinary Science》2006,26(1):27-31
Tenoscopy is the use of an arthroscope to access tendon sheaths. This article reports clinical findings, treatments, and outcomes of 33 horses with either septic or nonseptic digital tenosynovitis submitted to 36 tenoscopies during 34 occasions at the Marion duPont Scott Equine Medical Center (1997–2001). Two of the 16 horses with septic tenosynovitis were euthanized at the hospital. From the 32 horses discharged from the hospital, outcome was obtained in 31 cases: 12 horses (6 septic) could work at the same level. No difference was detected between the outcome groups regarding clinical and laboratory variables. In nonseptic cases, lameness grade, circulating white blood cells, and plasma fibrinogen before surgery were lower, while the period between the onset of clinical signs and surgery was longer and duration of phenylbutazone treatment and hospitalization was shorter. No difference in the outcome was detected when septic and nonseptic cases were compared. Tenoscopy was useful for diagnosis and treatment of nonseptic and septic digital tenosynovitis. The small number of cases and the lack of accurate information due to the retrospective nature of the study may have prevented detection of a difference between the outcomes of horses with septic versus nonseptic tenosynovitis. 相似文献
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评价在布氏杆菌病不同流行程度情况下用流产布氏杆菌RB51和19号苗免疫牛群 ,经过12个月后 ,牛体所产生的保护性免疫情况。实验动物为450头血清阴性母牛 :330头犊牛(3 -8个月龄) ,120头后备母牛(10-12月龄)。分别来源于A区(发病率为39 %)和B区(发病率为2%)。285头牛用RB51苗免疫一或二次 ,165头牛用19号苗免疫一次 ,剂量均为5×109个克隆单位。免疫后 ,分别从两组中抽取74(占26 %)和30头(占18 %)与血清阳性公牛交配 ,并在原先已感染的牛群中饲养。30天以后 ,所有接种19号苗的牛血清转阳 ,而285头RB51苗接种的牛群经血清学检测(包括琼脂免疫扩散)均为阴性结果 ,并且怀孕母牛及其第一胎犊牛也为阴性。由此可见 :RB51菌苗可用作活体免疫 ,且不产生影响血清学检测诊断的抗体滴度 ,保护率达100% ,可有效地抵抗B型流产布氏杆野毒侵袭 ,在配种前免疫 ,免疫期可持续至少一年。在相同条件下 ,RB51菌苗比19号苗有效可靠。 相似文献
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