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31.
西藏野生动物资源及其监测体系的探讨 总被引:1,自引:0,他引:1
结合西藏2000年野生动物资源监测调查,对监测调查结果进行了分析与评价,在此基础上,对建立西藏野生动物资源监测体系进行了探讨。 相似文献
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The majority of pregnancy loss in ruminants occurs during the first three weeks after conception, particularly during the period of conceptus elongation that occurs prior to pregnancy recognition and implantation. This review integrates established and new information on the biological role of ovarian progesterone(P4), prostaglandins(PGs),interferon tau(IFNT) and cortisol in endometrial function and conceptus elongation. Progesterone is secreted by the ovarian corpus luteum(CL) and is the unequivocal hormone of pregnancy. Prostaglandins(PGs) and cortisol are produced by both the epithelial cells of the endometrium and the trophectoderm of the elongating conceptus. In contrast, IFNT is produced solely by the conceptus trophectoderm and is the maternal recognition of pregnancy signal that inhibits production of luteolytic pulses of PGF2αby the endometrium to maintain the CL and thus production of P4. Available results in sheep support the idea that the individual, interactive, and coordinated actions of P4, PGs, IFNT and cortisol regulate conceptus elongation and implantation by controlling expression of genes in the endometrium and/or trophectoderm. An increased knowledge of conceptus-endometrial interactions during early pregnancy in ruminants is necessary to understand and elucidate the causes of infertility and recurrent early pregnancy loss and provide new strategies to improve fertility and thus reproductive efficiency. 相似文献
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为了解决基于模型的控制方法在四足机器人步态转换过程中稳定控制问题,本文在仿生学和机构学基础上设计了一款四足机器人样机平台,并推导了机器人单腿运动学模型。在足端可达工作空间内规划了机器人抬腿高度和迈步步长,利用理想的复合摆线轨迹,通过合理控制步态周期,提出了一种过渡段变周期控制方法,实现了步态转换前后定速度控制和变步长控制,保证了步态转换前后速度不变或可变。为了验证所提算法的正确性和稳定性,分别开展了单腿足端轨迹实验和整机步态转换实验。在完成整机运动控制的基础上,对比了基于模型的控制方式和基于中枢模式发生器的控制方式在四足机器人步态转换过程的应用。仿真和实验结果表明,在基于模型的控制算法下,四足机器人可以实现步态的平滑转换,且速度能伴随步长和周期的变化实现调节,满足了不同速度下的行走要求,为四足机器的运动控制提供了参考。 相似文献
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Two non-invasive blood pressure (NIBP) devices (oscillometry and Doppler) were compared to invasive blood pressure using a Bland–Altman analysis, in anesthetized and conscious dogs. When considering the systolic arterial pressure only during general anesthesia, both NIBP devices slightly underestimated the systolic arterial blood pressure however the precision and the limits of agreement for the Doppler were of a greater magnitude. This indicates a worse clinical performance by the Doppler. The performance of both NIBP devices deteriorated as measured in conscious animals. In general, for the oscillometric device, determination of invasive diastolic and mean arterial pressures was better than the invasive systolic arterial pressure. Overall, the oscillometric device satisfied more of the criteria set by the American College of Veterinary Internal Medicine consensus statement. Based upon these results, the oscillometric device is more reliable than the Doppler in the determination of blood pressure in healthy medium to large breed dogs. 相似文献
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T.A. Burns M.R. Watts P.S. Weber L.J. McCutcheon R.J. Geor J.K. Belknap 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(4):1280-1288
Background
In EMS‐associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5′‐Adenosine‐monophosphate‐activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR.Hypothesis/Objectives
To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge.Animals
Twenty‐two mixed‐breed ponies.Methods
Immunohistochemistry and immunoblotting for total AMPK and phospho(P)‐AMPK and RT‐qPCR for AMPK‐responsive genes were performed on laminar, liver, and skeletal muscle samples collected after a 7‐day feeding protocol in which ponies stratified on body condition score (BCS; obese or lean) were fed either a low‐CHO diet (ESC + starch, approximately 7% DM; n = 5 obese, 5 lean) or a high‐CHO diet (ESC + starch, approximately 42% DM; n = 6 obese, 6 lean).Results
5′‐Adenosine‐monophosphate‐activated protein kinase was immunolocalized to laminar keratinocytes, dermal constituents, and hepatocytes. A high‐CHO diet resulted in significantly decreased laminar [P‐AMPK] in lean ponies (P = .03), but no changes in skeletal muscle (lean, P = .33; obese, P = .43) or liver (lean, P = .84; obese, P = .13) [P‐AMPK]. An inverse correlation existed between [blood glucose] and laminar [P‐AMPK] in obese ponies on a high‐CHO diet.Conclusions and Clinical Importance
Laminar tissue exhibited a normal response to a high‐CHO diet (decreased [P‐AMPK]), whereas this response was not observed in liver and skeletal muscle in both lean (skeletal muscle, P = .33; liver, P = .84) and obese (skeletal muscle, P = .43; liver, P = .13) ponies. 相似文献39.
J. Burns S. Hou C.B. Riley R.A. Shaw N. Jewett J.T. McClure 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(2):639-645
Background
Rapid, economical, and quantitative assays for measurement of camelid serum immunoglobulin G (IgG) are limited. In camelids, failure of transfer of maternal immunoglobulins has a reported prevalence of up to 20.5%. An accurate method for quantifying serum IgG concentrations is required.Objective
To develop an infrared spectroscopy‐based assay for measurement of alpaca serum IgG and compare its performance to the reference standard radial immunodiffusion (RID) assay.Animals
One hundred and seventy‐five privately owned, healthy alpacas.Methods
Eighty‐two serum samples were collected as convenience samples during routine herd visits whereas 93 samples were recruited from a separate study. Serum IgG concentrations were determined by RID assays and midinfrared spectra were collected for each sample. Fifty samples were set aside as the test set and the remaining 125 training samples were employed to build a calibration model using partial least squares (PLS) regression with Monte Carlo cross validation to determine the optimum number of PLS factors. The predictive performance of the calibration model was evaluated by the test set.Results
Correlation coefficients for the IR‐based assay were 0.93 and 0.87, respectively, for the entire data set and test set. Sensitivity in the diagnosis of failure of transfer of passive immunity (FTPI) ([IgG] <1,000 mg/dL) was 71.4% and specificity was 100% for the IR‐based method (test set) as gauged relative to the RID reference method assay.Conclusions and Clinical Importance
This study indicated that infrared spectroscopy, in combination with chemometrics, is an effective method for measurement of IgG in alpaca serum. 相似文献40.