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901.
Liu Q  Zhao JL  Zhou YQ  Liu EY  Yao BA  Fu Y 《Veterinary parasitology》2005,130(3-4):191-198
The study on buffalo babesiosis indicated that its pathogen was different from other Babesia on many aspects such as morphology, transmission and pathogenicity. Therefore, it was named as a new species—Babesia orientalis. In order to prove the validity of this taxon, molecular taxonomic study on the pathogen was done in this experiment. The complete 18S rRNA gene sequence of B. orientalis was determined by PCR. It was sequenced and blasted. The results indicated that the classification of the parasite belonged to the genus Babesia. The 1700 bp complete sequence was compared with 15 other Babesia sp. available in GenBank. The data were analyzed and a phylogenetic tree was established. The results indicated that the hereditary distance of the parasite was close to that of Babesia sp. from South Africa and Babesia ovis, and the hereditary distance was far from Babesia bigemina and B. bovis.  相似文献   
902.
本文记述了采自辽宁省本溪县的隆侧姬峰属一新种,辽宁隆侧姬蜂Latibulusliaonigensis,sp.n..并指出了它和近似种:东方隆侧姬蜂L.orientalisHorstmann的主要区别特征.  相似文献   
903.
本文通过对18个杨树品种无性系在9个试验点的G×E互作分析,用8个参数评价生产力,遗传稳定性和生长适应性,并经综合评定,从村冠积比(材积/冠积)方面将18个品系划分为不同类型,为各试验区评选出了适合栽培的优良品系。  相似文献   
904.
干草原牧草贮藏碳水化合物含量变化规律的研究   总被引:11,自引:1,他引:10  
1993年在内蒙古正蓝旗于草原对10种牧草贮藏碳水化合物含量的变化规律进行了研究。在植物生长期内,每15天采样一次,分析牧草茎基部和根部的总糖和还原糖含量。试验结果表明,牧草在返青时都要消耗贮藏碳水化合物,分蘖后开始积累贮藏碳水化合物,在拔节和抽穗时又要消耗贮藏碳水化合物,开花、结实后又积累贮藏碳水化合物。但有的牧草出现相反的情况。根据牧草贮藏碳水化合物含量变化的规律,作者对合理利用草地提出了一些意见和建议。  相似文献   
905.
跗线螨属一新种(螨目 跗线螨科)   总被引:3,自引:0,他引:3  
本文描述跗线螨属一新种,新种Tarsonemus kropf与T.schlechtendali Suski1966很相似,但其Ta毛生于表皮内突Ⅰ上或紧靠其下;3b毛生于表皮内突Ⅳ的下端;背面e毛长于f毛;前中表皮内突与表皮内突Ⅱ相接。模式标本分别存放于甘肃农业大学植保系和德国联邦农林生物研究中心葡萄保护研究所。  相似文献   
906.
四川大蚊属新种记述(双翅目:大蚊科)   总被引:1,自引:0,他引:1  
  相似文献   
907.
Recent changes in the trophic structure of the Black Sea   总被引:11,自引:0,他引:11  
During the past few decades, the Black Sea has been subjected to various human impacts that have led to changes in the ecology of this inland sea. River runoff has introduced high levels of certain heavy metals and other toxic substances as well as detergents. Ship traffic has led to the introduction of new species, and fishing pressures have also altered the ecology of the area.
This paper reviews major ecological changes over the past 40 years. An increase in nutrients has caused eutrophication, with outbursts of phytoplankton blooms and changes in the species composition of these algae. Small-sized zooplankton species and gelatinous zooplankton have become more common, while many of the herbivorous copepods have decreased in abundance or have disappeared. The introduction of the predatory ctenophore Mnemiopsis leidyi in the 1980s has had significant impact on the plankton community and has led to a sharp decline in anchovy stocks. Decreased water transparency has led to a loss of macrophytic algae, except in shallow waters, and to a subsequent decline in the zoobenthos associated with this flora. Eutrophication has also led to decreased oxygen concentrations in the near-bottom water due to large amounts of decomposing phytoplankton, and regions of hypoxia and anoxia now appear on the shelf, with consequent reduction in benthic populations of invertebrates and demersal fish. The numbers of fish species harvested commercially have fallen from 26 to 5, but the total catch has increased, owing to increases in abundance of small fish (e.g., sprat) and horse mackerel, and to increased fishing effort.  相似文献   
908.
High-resolution ultrasonography was evaluated as an alternative to 99mTcO-4 scintigraphy for examining size and appearance of thyroid glands in hyperthyroid cats. Thyroid ultrasound examinations were performed on 6 normal cats and 14 cats with hyperthyroidism. Thyroid lobe volume was estimated from ultrasound images using the equation for a prolate ellipsoid, π/6 (length * height * width). Total thyroid volume was estimated by adding the volume estimations of the left and right lobes. Thyroid lobes of hyperthyroid cats were considered abnormal if estimated volume exceeded the 99% confidence interval for normal thyroid volume determined from the control group. Scintigraphic examinations performed on hyperthyroid cats were evaluated for unilateral versus bilateral disease and for the presence of ectopic activity. Mean thyroid lobe volume and total thyroid volume for normal cats was 85 and 169 mm3, respectively. Mean thyroid lobe volume and total thyroid volume for hyperthyroid cats was 578 and 889 mm3. There was a significant difference in mean estimated total thyroid volume of normal and hyperthyroid cats. Thyroid lobes with greater than normal TcO-4 uptake on scintigraphy were larger and had variable homogeneity, echogenicity, and margination on ultrasound examination. There also was an 85.7% agreement of scintigraphy and ultrasonography in differentiating normal from abnormal thyroid lobes. A fair correlation between estimated total thyroid volume of hyperthyroid cats and most recent pretherapy serum thyroxine values were also found. This preliminary study indicates that thyroid ultrasound examination may provide information that is useful for diagnosis and treatment of feline hyperthyroidism. Although ultrasound provides accurate evaluation of the thyroid glands, it cannot replace 99mTcO-4 scintigraphy for screening of metastatic lesions and ectopic glands.  相似文献   
909.
黄土丘陵区四种人工灌木植被生态经济效益分析   总被引:4,自引:1,他引:3  
以定西地区常见人工灌木树种柠条、沙棘、红柳、紫穗槐为研究对象,利用生态经济学原理提出其生态经济效益评价的指标体系和评价方法,通过农村社会调查和市场分析并结合影子价格法、机会成本法和影子工程法等方法.分别计算四种灌木的生态经济效益。综合效益分析表明,四种灌木树种生态效益大小顺序为沙棘>红柳>柠条>紫穗槐,经济效益大小顺序为紫穗槐>沙棘>红柳>柠条。从总净收益来看,四种灌木生态经济效益总和大小顺序为沙棘>紫穗槐>红柳>柠条。表明沙棘是该区优良的植被恢复灌木树种,适宜在定西地区大面积推广。  相似文献   
910.
Heart disease has been described in the chinchilla and, with increasing popularity as a pet, the demand for diagnostic evaluation and treatment has increased. The goal of this study was to determine reference values for echocardiographic measurements in chinchillas and the effect of anesthesia on these measurements. Seventeen clinically healthy adult chinchillas were studied. All animals were anesthetized with isoflurane by mask. Standard echocardiographic views were used. A difference was seen in the echocardiographic measurements for left ventricular systolic dimension, fractional shortening, aortic (Ao) diameter, left atrial (LA) diameter, ratio of LA diameter to Ao diameter, and peak flow velocities and ejection times for Ao and pulmonary artery flows between awake and anesthetized chinchillas.  相似文献   
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