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71.
Giardia intestinalis is a pathogenic protozoan which infects humans and a wide range of animal hosts, including cats and dogs(1). However, the status of animals in New Zealand with respect to Giardia infection has not received much attention, so we undertook a preliminary study of cats and dogs in Palmerston North and Hamilton to determine the prevalence of infection, as indicated by the presence of cysts in faeces.  相似文献   
72.
Objective   Evaluate the sensitivity and specificity of transrectal ultrasound and transcutaneous ultrasonography across the right flank between days 31 and 196 of pregnancy in the dairy cow.
Procedure   Pregnancy status and stage of gestation at date of pregnancy diagnosis by transcutaneous and transrectal ultrasonography were determined for 1570 dairy cattle. Sensitivity and specificity values and probabilities of a correct diagnosis for both techniques were determined and compared. Possible effects of gestational age, herd, method of transcutaneous ultrasound diagnosis, cow age, cow and bull breed, and calf sex on the determination of a correct diagnosis of pregnancy status were evaluated for both techniques.
Results   The overall sensitivity and probability of a correct diagnosis of pregnancy status from days 31 to 196 of gestation were significantly higher when using transrectal ultrasound relative to transcutaneous ultrasound over the right flank. However, the sensitivity of transcutaneous ultrasound changed over the course of pregnancy: it was low (7–8%) before day 84, increased to 89% between days 141 and 154, and was close to 100% thereafter. The specificity of both methods did not differ significantly. Herd and gestational age at date of pregnancy diagnosis were significantly associated with making a correct test result using transcutaneous ultrasound, although only the latter predictor was significantly associated with making a correct test result using transrectal ultrasound.
Conclusion   Transcutaneous ultrasound can not be recommended as an accurate method for early pregnancy diagnosis in the dairy cow, particularly on a whole-herd basis. However, if pregnancy testing is undertaken in mid to late gestation, this technique could provide an accurate and rapid alternative to transrectal ultrasound or manual palpation per rectum.  相似文献   
73.
Luteinizing hormone LH plays important roles in follicular maturation and ovulation. The effects of LH are mediated by LH receptor (LHR) in the ovary. However, the factors that regulate the expression of LHR in bovine granulosa cells (GCs) are not well known. Insulin‐like growth factor‐1 (IGF‐1) is known to play a key role in the acquisition and maintenance of functional dominance. To better understand the roles of LHR expression and IGF‐1, we conducted three experiments to determine (i) mRNA expression of LHR in the GCs of developing follicles, (ii) the effects of IGF‐1 on LHR mRNA expression in cultured GCs and (iii) the effects of IGF‐1 on estradiol (E2), progesterone (P4) and androstenedione (A4) production by non‐luteinized GCs. In experiment 1, small follicles (<6 mm Ø) expressed lower levels of LHR than mid‐sized follicles (6–8 mm Ø) and large follicles (≥9 mm Ø) expressed the highest levels of LHR mRNA (p < 0.05). In experiment 2, IGF‐1 (1 and 100 ng/ml) increased (p < 0.05) the expression of LHR mRNA in GCs from small and large follicles. In experiment 3, IGF‐1 (0.1–100 ng/ml) increased A4 and E2 in GCs from both small and large follicles but increased P4 only in large follicles. IGF‐1 in combination with LH (0.1 and 1 ng/ml) increased P4 and A4 in large follicles, and increased E2 and A4 in GCs of small follicles. These findings strongly support the concept that IGF‐1 upregulates LHR mRNA expression as well as A4 and E2 production in GCs and that IGF‐1 is required for determining which follicle becomes dominant and acquires ovulatory capacity.  相似文献   
74.
各位专家,同志们: 首先,请允许我代表农业部兽药审评委员会办公室和中国兽医药品监察所,对参加本次培训研讨会议的专家和老师们表示热烈的欢迎,同时也借此机会向对圆满完成审评工作任务的第三届审评委员会委员表示衷心的感谢!  相似文献   
75.
In the flash-lag illusion, a flash and a moving object in the same location appear to be offset. A series of psychophysical experiments yields data inconsistent with two previously proposed explanations: motion extrapolation (a predictive model) and latency difference (an online model). We propose an alternative in which visual awareness is neither predictive nor online but is postdictive, so that the percept attributed to the time of the flash is a function of events that happen in the approximately 80 milliseconds after the flash. The results here show how interpolation of the past is the only framework of the three models that provides a unified explanation for the flash-lag phenomenon.  相似文献   
76.
77.
Geophysical models show that electrical conductivity in Earth's mantle rises about two orders of magnitude through the transition zone in the depth range 410 to 660 kilometers. Impedance measurements obtained on Mg1.8Fe0.2SiO4 olivine, wadsleyite, and ringwoodite at up to 20 gigapascals and 1400 degreesC show that the electrical conductivities of wadsleyite and ringwoodite are similar and are almost two orders of magnitude higher than that of olivine. A conductivity-depth profile to 660 kilometers, based on these laboratory data, shows a conductivity increase of almost two orders of magnitude across the 410-kilometer discontinuity; such a profile favors a two-layer model for the upper mantle. Activation enthalpies of 1.2 to 1.7 electron volts permit appreciable lateral variations of conductivity with lateral temperature variations.  相似文献   
78.
同志们: 正值"两会"和全党开展"保持共产党员先进性教育活动"期间,全国兽药监察所所长会议在石家庄市召开.这次会议的主要任务是:以保持共产党员先进性教育为契机,全面贯彻全国农业工作会议畜牧兽医专业会议精神和新颁布的<兽药管理条例>,认真总结2004年全国兽药质量监督工作,进一步分析兽药质量监督工作面临的新形势,研讨2005年的工作重点,坚持科学发展观,创新兽药监察工作思路,大力推进兽药监察工作.  相似文献   
79.
Objective To study differences in experiences, attitudes and opinions between female and male veterinary students and recent graduates.
Design Longitudinal study.
Population Students – 77 males and 77 females – who began studying veterinary science at The University of Queensland in 1985 and 1986.
Procedure Questionnaires were completed in the first and fifth year of the course, and in the second year after graduation. The data were analysed using the SAS System for Windows.
Results Females decided to study veterinary science at a younger age than males and were more influenced by 'a love of animals', the image of veterinarians as portrayed on television, an interest in living things and in the scientific study of disease. Males were more influenced than females in aspects of the workplace: bosses and money. There were no gender differences in their background in relation to farms, or to animals, or in their career plans. However females when in first year expected a lower initial income than males; an expectation that was realised in the first year after graduation. As first year students and also as veterinarians, females had stronger views than males on animal welfare issues, and also felt that the veterinary profession had a lower status relative to other professions.
Conclusions Significant differences in attitudes and experiences exist between males and females entering the veterinary profession. The situation of females in relation to income and status is consistent with that in other professions, where females have been disadvantaged compared with males.  相似文献   
80.
SUMMARY Australia and the USA are major international meat exporting countries. Both countries conduct programs to monitor and survey for antibacterial residues. Australian programs use a urine screening test, whereas the US programs use tissue fluids as the test medium. The development of surveillance programs to provide rapid feedback to producers is a feature of the Australian programs. The programs in each country compare favourably with regard to numbers of animals tested, results and action taken to prevent residues. The results of the Australian programs justify the promotion of a ‘clean food’ image for Australian meat products with respect to antibacterial drugs.  相似文献   
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