入世风险与农村现行双层经营制度的变迁     

黄兴年  马敬桂 《湖北农学院学报》2002,22(6):515-519

中国加入WTO之后 ,农民不仅要承担其他国家农民所承担的自然风险与市场风险 ,还要承担因现行双层经营制度带来的预期不确定性的风险 ,其根源在于现行的经营制度呈现出极大的“体制锁定”的色彩。要打破这种体制锁定 ,必须两条腿走路 :诱致性创新与强制性创新并举。既精减机构 ,明确政府的责、权、利 ,又扶植与培育农民联合体 ,增强市场创新主体分摊成本的能力与赢利能力 ,从而确保新体制的生命力与竞争力。  相似文献   

区域证券市场发展潜力评价模型的建立及实证分析     

杨军  姚天祥  徐广印 《河南农业大学学报》2001,35(1):84-88

建立了评价区域证券市场发展潜力的数学模型－定权聚类评估模型，并对河南各地区证券发展潜力进行了实证研究。  相似文献   

A Tremor Syndrome With a Central Axonopathy in Scottish Terriers     

Luc Van  Ham  Marc Vandevelde  Miek Desmidt  Mulenda Tshamala  Luc De  Schaepdrijver Daniel Mattheeuws 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1994,8(4):290-292

A central axonopathy in 2 male and 1 female Scottish Terrier puppies from 3 different but related litters is reported. Clinical signs consisting of severe whole-body tremors and ataxia were first detected at the age of 10 to 12 weeks. They worsened with activity and excitement and diminished during rest or sleep. Two dogs also had paraparesis. In 1 dog the neurological deficits progressed over several months. Neuropathological examination revealed widespread axonal changes, vacuolation, and gliosis in the white matter of the central nervous system.  相似文献   

鼻气管鸟杆菌对鸡的感染及其防制     

程思明  任文雁  Peter De Herdt 《国外畜牧学(猪与禽)》2002,(1):50-52

鼻气管鸟杆菌发现于 1 990年 ,自那时以来已在世界范围内被公认为一种呼吸道病原菌 ,可在肉用鸡引起原发感染或继发感染。对种鸡进行免疫接种是减轻鼻气管鸟杆菌所致经济损失的有效方法。  相似文献   

D-LysAsnProTyr四肽对肉仔鸡免疫及主要生产性能的影响   总被引：1，自引：0，他引：1  

徐秋良  刘兴友  姚军虎 《中国兽医杂志》2005,41(10):3-6

将体重、发育及健康状况接近的300羽7日龄肉仔鸡随机等分为5个处理，每个处理设3重复，每重复20羽。试鸡用D-LysAsnProTyr四肽＋3头份新城疫Ⅳ系疫苗生理盐水混合液滴鼻，剂量为50μl／只，D-LysAsnProTyr四肽水平为：0μg／只（对照组），15μg／只，20μg／只，25μg／只，30μg／只。测定新城疫抗体水平及淋巴细胞ANAE阳性百分率，计算全期平均日增重、采食量和料肉比。结果表明，D-LysAsnProTyr四肽在20～25μg／只鸡剂量对ND抗体有明显的提高作用，不改变抗体变化规律；显著提高肉仔鸡血液中淋巴细胞阳性百分率，10～42日龄20μg／只和25μg／只试验组分别比对照组提高2．03～9．47个百分点和2．36～9．22个百分点，淋巴细胞阳性百分率的增减变化规律与对照组相一致，说明适宜剂量D-LysAsnProTyr四肽可以显著提高肉仔鸡对ND的体液免疫和细胞免疫。20μg／只、25μg／只组试期末体重、平均日增重显著高于15μg／只、30μg／只组（P〈0．05）。与20μg／只、25μg／只组相比，对照组日增重、饲料转化率有降低趋势（P〉0．05）。各处理组对肉仔鸡日均采食量无显著影响（P〉0．05）。  相似文献   

Computed tomography of the tarsal joint in clinically normal dogs.     

I M Gielen  L M De Rycke  H J van Bree  P J Simoens 《American journal of veterinary research》2001,62(12):1911-1915

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The relationship between feeding and fertility in dairy cattle]     

A De Kruif  P Mijten 《Berliner und Münchener tier?rztliche Wochenschrift》1992,105(8):271-279

The possible relationship between nutrition and fertility in dairy cows are reviewed. Study of the literature shows that opinions on the effect of the various nutrients differ markedly. The conclusion which can be made is that in countries where standards of dairy farming are high, nutrition only plays a minor role in the problem of herd subfertility. In the course of time deficiencies in a large number of minerals, trace elements and vitamins have been stressed as a cause of inadequate fertility. However cows are at present generally fed with a lot of well balanced concentrates and therefore deficiencies are very unlikely to occur. During early lactation every high producing dairy cow has a negative energy balance. In a number of cows this results in anoestrus and in a long interval from parturition to first insemination. Overfeeding during late lactation and the dry period does not adversely affect subsequent reproduction but may cause puerperal disorders. The relation between protein nutrition and fertility is complex. Protein effects on fertility are minor. Problems can arise if there is a combination of a high percentage of crude protein (greater than 18%), a high rumen degradability of the protein and a low energy content of the diet. The value of metabolic profile tests is minimal because they do not differentiate between normal herds and herds with fertility problems.  相似文献   

Sensitivity of four Yeasts to Fungicides and CO2 Concentrations and Their Antagonistic Ability in Combination with Fungicide to pathogenic Fungi in vitro     

TIAN Shi-ping  YAO Hong-jie  QIN Guo-zheng  XU Yong  FENG Xiao-yuan 《中国农业科学(英文版)》2004,3(3)

The yeasts Cryptococcus laurentii,Trichosporon pullulans,Rhodotorula glutinis and Trichosporon sp.were used to investigate their sensitivity to four fungicides and different concentrations of CO2,as well as their antagonistic ability to Penicilliumexpansum and Alternaria alternata in vitro when applied with fungicide.There were significant differences in sensitivity to the fungicides among the different yeasts(P = 0.05).R.glutinis was more sensitive to Deccocil,Iprodione and Stroby as compared to other yeasts.Combination antagonistic yeasts with fungicide could more significantly enhance biocontrol ability of the yeasts against the pathogenic fungi in vitro(P = 0.05).C.laurentii was the most effective antagonist among the four yeasts and could completely control spore germination of P.expansum and A.alternata when combined with Stroby at the concentration of 100 μL L-1.The yeasts,except R.glutinis,could grow well on nutrient yeast dextrose agar (NYDA) after 8 d incubation even at 20% CO2 concentration at 25℃.Particularly Trichosporon sp.showeda better adaptability to low temperature as compared to other antagonists.  相似文献   

Evaluation of an electronic device used as a quick screening method to detect changes in the red cell content of the blood in horses participating in endurance trail rides     

A. De Waal  F. J. Potgieter 《Veterinary research communications》1991,15(4):309-314

Dehydration, to varying degrees, will inevitably occur in horses participating in endurance trail rides. This water loss is directly related to the amount of body water lost through evaporative cooling, that in turn being related to the amount and rate of work performed, and to the environmental temperature and humidity.An electronic apparatus that can substitute for the conventional and time-consuming venous haematocrit was developed to measure the animals' hydration status. The mechanism of this electrometer is based upon the relationship between the red cell content and the electrical conductivity of the blood. The electrometer reading gave a significant correlation (p<0.001) with the venous haematocrit, thus indicating that the electrometer is a reliable apparatus for determining the animals' hydration status within seconds of venepuncture.  相似文献   

Incidence of Salmonellae in Captive and Wild Free‐Living Raptorial Birds in Central Spain     

M. P. Reche  P. A. Jimnez  F. Alvarez  J. E. García de los Ríos  A. M. Rojas  P. De Pedro 《Zoonoses and public health》2003,50(1):42-44

A total of 595 faecal samples from raptorial birds, either captive or free‐living, residing in GREFA Wildlife Hospital were bacteriologically examined using various selective media and an Automated Diagnostic Assay System for Salmonella detection. Serotype and phage type of the strains identified as Salmonella was determined. In the captive group, of the 285 samples examined, 21 (7.36%) were positive for Salmonella. Serotyping revealed that most of the individuals were infected by Salmonella serotype Havana. This result suggested that there could be a source of contamination in the Hospital although it could not be established. In the wild free‐living group, over 310 samples examined (4.19%) were positive for Salmonella. The Salmonella isolates showed a major variety of serotypes: Enteritidis, Adelaide, Brandenburg, Newport, Typhimurium, Hadar, Saintpaul and Virchow. Most of them are similar to those commonly described in isolates from human and domestic animals. These results indicate that wild birds could be involved in the dissemination of Salmonella in humans or domestic animals or vice versa.  相似文献