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基于遥感的大面积长时序草地物候监测是物候生态学的重要领域,也是全球变化研究的重要方向。基于30年(1986-2015年)时间序列GIMMS 3g归一化植被指数(NDVI),利用Savitzky-Golay滤波法进行时间序列重建,并用动态阈值法提取中国天然草地物候参数[生长季始期(SOS)、生长季末期(EOS)、生长季长度(LOS)],然后以1998年为时间分界点,利用提取的3种物候参数对前后两个时间段内的草地物候特征的时间演化趋势及空间分异进行分析。结果表明:1)全国草地年平均SOS、EOS和LOS分别主要集中在第100~140天、260~290天和130~170天;2)物候趋势在30年时间尺度上没有显著变化,幅度为-0.3~0.3 d·yr-1;3)在1998年之前,全国草地SOS平均提前速率为0.37 d·yr-1,EOS平均推迟速率0.43 d·yr-1,且空间差异较大,在1998年之后草地物候变化趋势出现转变,草地SOS变化幅度最大,平均推迟速率为0.28 d·yr-1;4)高山亚高山草甸、山地草原、平地草原和高山亚高山平地草原在1998年后物候特征变化趋势出现与之前完全相反的转折。提取物候结果与观测资料和相关研究结果较为一致。 相似文献
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Bussadori C Pradelli D Borgarelli M Chiavegato D D'Agnolo G Menegazzo L Migliorini F Santilli R Zani A Quintavalla C 《Veterinary journal (London, England : 1997)》2009,182(2):187-192
This prospective study was conducted to evaluate the prevalence and severity of ocular lesions in dogs with anemia (packed cell volume 20%) and/or thrombocytopenia (platelet count < 150,000/μL). Dogs were divided into four groups: (1) anemic (n = 17); (2) thrombocytopenic (n = 36); (3) anemic and thrombocytopenic (n = 24); and (4) healthy controls (n = 26). The prevalence of ophthalmic lesions in these four groups was 12%, 42%, 42% and 0%, respectively. Anemia was not associated with the presence of ocular lesions (P = 0.41) or their severity. Thrombocytopenia was significantly associated with the presence of ocular lesions (P = 0.0016) and with their severity (P = 0.017). We conclude that thrombocytopenia, but not anemia, is associated with ocular lesions in dogs. 相似文献
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草地系统的安全健康关系到当地畜牧业的可持续发展。运用1978-2008年天水市关山南麓地区历年畜群数及清水、张家川气象站牧草生长期历年日照时数、平均温度及降水量测量值,构建评价该地草地压力的指数模型分析该地区畜群数、草地生产潜力及草地压力指数的动态变化。结果表明:近30年来天水市关山南麓地区畜群数随年份以1.76×104羊单位/a的速度逐年增加,草地生产潜力变化不大,草地生态压力指数以0.02/a的速度逐年上升。近5年来草地严重超载,畜群数已超过了草地的承载能力。适当限制畜群规模及扩大草地面积是未来当地畜牧业可持续发展的主要途径。 相似文献
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Neosporosis in animals--the last five years 总被引:2,自引:0,他引:2
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Food hypersensitivity in 30 dogs 总被引:1,自引:0,他引:1
S D White 《Journal of the American Veterinary Medical Association》1986,188(7):695-698
Food hypersensitivity was diagnosed in 30 dogs. Clinical signs varied, with pruritus (97%), erythema (50%), and papules (37%) being the most common. Diagnosis was based on resolution of clinical signs when the dogs were fed a restricted ("hypoallergenic") diet, and recurrence of signs when fed their original diet or other foods. No age, breed, or sex predilection was noticed. None of the owners could relate the onset of clinical signs with a recent change in diet. Seven dogs had concurrent fleabite, inhalant, intestinal parasite, or insulin hypersensitivity. 相似文献
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OBJECTIVES: To document the outcome, survival and complications involved in pacemaker implantation in dogs in a retrospective study. METHODS: Case records for all dogs in which pacemaker implantation was performed were reviewed. RESULTS: A total of 104 dogs underwent pacemaker implantation. Dogs were presented with atrioventricular (AV) block (71), sick sinus syndrome (25) or vasovagal syncope (eight). Age at presentation varied from six months to 13 years with a median age of seven years and two months. The Labrador was the most commonly represented breed (17 cases). All but one dog survived pacemaker implantation, with 93 showing resolution of their clinical signs while 10 dogs showed intermittent residual signs. One-, three- and five-year survival estimates were 86, 65 and 39 per cent, respectively. Major complications after implantation were documented in 15 dogs and three of these led to fatalities. Minor complications were noted in 23 dogs. Sudden death occurred in six dogs three to 55 months following successful pacemaker implantation. CLINICAL SIGNIFICANCE: Transvenous pacemaker implantation was successful in reducing or eliminating clinical signs in over 90 per cent of dogs with third-degree atrioventricular (AV) block or sick sinus syndrome. In dogs with vasovagal syncope, six of eight dogs had greatly reduced frequency of collapse and two became asymptomatic. Although the procedure was associated with complications, these were rarely life threatening and good survival was documented in the majority of cases. 相似文献
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Canine semen cryoconservation was used since 1969, and this process is still nowadays in progress. This review aims to have an overview of two factors leading to a successful freezing–thawing semen. The success and efficiency of freezing process can be measured by the post-thawing sperm mobility. The first factor is the best extender used as a cryoprotectant to have a similar osmolarity and pH compared to the seminal plasma to enable sperm survival. Historically, chicken egg yolk was used since 1940, but due to microbial risks and to the presence of granules (which interfere with counting dead spermatozoa and inhibits a spermatozoal respiration), despite these disadvantages, egg yolk is considered an excellent cryoprotectant for sperm of different animal species. The low-density lipoproteins (LDL), contained in EY, when used at a concentration of 6% in a freezing medium associated with 20 mM of glutamine, show a mobility up to 54.5%, which is the best combination found. However, the sperm protection mechanism by LDL during freezing–thawing process only begins to be decrypted. But extraction protocols of LDL are not efficient for an industrial use. Therefore, egg yolk plasma is used within liquid or lyophilized state, and offering similar efficiency as the 6% LDL middle. The equilibration step, in which the diluted sperm is placed for a variable period of time at a temperature of +4°C, before freezing it. The studies show that 6 hr is the optimal duration for the canine sperm equilibration. The future of canine sperm cryopreservation is expected in liposome use and synthetic substances, which mimics LDL role. 相似文献
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近两年(2000~2001年)来,农业部动物检疫所门诊的病禽中,经病毒分离、血清学调查证明为新城疫的病例共368例,发病禽数882394羽。我们对这些发病禽的流行病学进行了分析。1地区性如表1所示,其中来自青岛的共254例,平均发病日龄为111日龄,平均产蛋下将幅度为23%,平均死淘率为10.44%;来自潍坊的共42例,平均发病日龄为227日龄,平均产蛋下将幅度为31%,平均死淘率为7.99%;来自烟台的共40例,平均发病日龄为154日龄,平均产蛋下将幅度为29.27%,平均死淘率为20.79%… 相似文献
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Alessandro Di Cerbo Sara Centenaro Francesca Beribè Fulvio Laus Matteo Cerquetella Andrea Spaterna Gianandrea Guidetti Sergio Canello Giuseppe Terrazzano 《Veterinary research communications》2016,40(1):29-38
The aim of this evaluation study was to assess the possible role of a specific nutraceutical diet in relieving main clinical symptoms of chronic bilateral otitis externa (occlusion of ear canal, erythema, discharge quantity, and odor) in 30 adult dogs. Thirty dogs of different breeds (mean age?±?SEM; 6.03?±?0.15 years and mean weight?±?SEM; 32.01?±?1.17 Kg; 53.3 % males, 46.6 % females) with evident chronic clinical otitis symptoms were equally divided and randomly assigned to receive either the nutraceutical diet (ND group) or a standard diet (SD group) over a period of 90 days. In all cases a topical pharmacological treatment was given. The nutraceutical diet, also endowed with anti-inflammatory and antioxidant activities, significantly decreased the mean score intensity of all symptoms after 90 days of intervention (P?<?0.0001) with the exception of Malassezia pachydermatis infection which was only slightly reduced. Our investigation is one of the few evidence-based results where a commercial nutraceutical diet has been proven effective, in combination with drugs, in relieving otitis externa-related symptoms. This study opens new insights into otitis externa clinical management providing evidence of efficacy of a combined therapy with drugs and a specific nutraceutical diet. 相似文献
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近10年鹿放牧生态研究进展 总被引:8,自引:2,他引:8
从鹿的放牧笔为特点,季节动态、生物因素、非生物因素以及劳动生产因素对鹿放笑话地为的影响,鹿放牧对草地植被的影响等方面,总结近10年来国内外在鹿放牧生态领域的研究进展,并对今后值得研究的方面提出建议。 相似文献
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近1O年鹿放牧生态研究进展 总被引:4,自引:2,他引:4
从鹿的放牧行为特点、季节动态、生物因素(草地植物和其他家畜)、非生物因素以及劳动生产因素(主要是放牧制度)对鹿放牧行为的影响,鹿放牧对草地植被的影响等方面,总结近10年来国内外在鹿放牧生态领域的研究进展.并对今后值得研究的方面提出建议. 相似文献
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Kopp SR Kotze AC McCarthy JS Traub RJ Coleman GT 《Veterinary journal (London, England : 1997)》2008,178(2):177-184
Pyrantel, a tetrahydropyrimidine nicotinic agonist anthelmintic, has been used in companion animal medicine since the 1970s to control two important nematode groups, the hookworms and the roundworms. Given the zoonotic potential of these parasites, pyrantel has served a dual role in helping to protect the health of both companion animals and the public for more than 30 years. This review describes the history and mechanism of action of this drug, and collates evidence that resistance to pyrantel has developed in at least one canine nematode, the hookworm Ancylostoma caninum. The role of in vitro diagnosis tests in managing anthelmintic resistance in companion animal parasites is discussed, as are management practices that may reduce the rate at which resistance develops. 相似文献
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Heath TJ 《Australian veterinary journal》2005,83(12):746-750
OBJECTIVE: To describe changes that have occurred over the last five decades in the career paths of veterinarians during the first 10 years after they graduated. DESIGN: A questionnaire, sent by mail. PROCEDURE: A questionnaire seeking information on experiences as a recent graduate was sent to about 100 veterinarians who graduated in or about 1950, 1960, 1970, 1980, 1990 and 2000, and 68% responded. Data were entered onto an Excel spreadsheet, and analysed with the SAS System 8 for Windows. RESULTS: Fifty years ago, about half of the graduates worked initially for a government under a cadetship contract. About half of them then left the government, mainly for mixed practice, and > 40% of the cohort remained in mixed practice. Cattle were > 40% of the case-load over the first 10 years, and dogs and cats were 22% at both the first and tenth year. For graduates of 1970, the percentage in government service remained at 27 to 28% over the 10 years, but that in mixed practice decreased from 51 to 25% between the first and fifth year, and was then fairly constant. The percentage in small animal practice, much higher than for graduates of 1950 and 1960, was 37% in the first year, and 45% in the tenth year. Overall dogs and cats increased from 34 to 47% and that of cattle decreased from 39 to 25% of the case-load between the first and tenth year. The graduates of 1990 continued the trends towards an exodus from mixed practice, and decrease in cattle (19 to 9%) and increase in dogs and cats (63 to 79%). Data from graduates of 2000 point to a continuation of these trends. Female graduates tended to concentrate in small animal practice in each of the 10 years after they graduated. CONCLUSIONS: Over the last five decades, the career paths of veterinary graduates over their first 10 years have increasingly involved (a) leaving initial positions in mixed practice, (c) less work with production animals, and (c) more work with dogs and cats. 相似文献
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草原虫害防治是农业部较早大规模组织开展的防灾减灾工作之一。在长期的实践工作中,草原虫害防治始终坚持“预防为主,综合防治”的植保方针,逐步建立了“以生物防治为主,化学防治为辅”的技术路线。2002年起,全国畜牧总站在全国牧区组织开展了《草原虫害生物防控综合配套技术推广应用》项目。该项目的实施带动了全国的草原害虫防治,为草原可持续发展提供了技术支撑。本文以该项目的进展为基础,简要总结介绍了草原害虫防治的实施背景、开展情况及建设成果,包括以生态系统平衡原理为指导,对虫害监测预警、生物防控和施药技术等进行集成创新与组装配套,使草原害虫密度长期控制在经济阈值以下,实现草原生态系统平衡等。 相似文献