首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   61篇
  免费   2篇
林业   2篇
农学   3篇
基础科学   3篇
  27篇
综合类   6篇
农作物   1篇
水产渔业   1篇
畜牧兽医   14篇
园艺   1篇
植物保护   5篇
  2023年   1篇
  2021年   1篇
  2020年   2篇
  2019年   2篇
  2018年   5篇
  2017年   2篇
  2016年   5篇
  2015年   4篇
  2014年   4篇
  2013年   10篇
  2012年   2篇
  2011年   5篇
  2010年   5篇
  2009年   4篇
  2008年   4篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2004年   3篇
排序方式: 共有63条查询结果,搜索用时 15 毫秒
1.
2.
Abstract: An 18-month-old male Doberman Pinscher was referred to the Veterinary Medical Teaching Hospital of the College of Veterinary Medicine for an erythemic nodular mass on the right forelimb. The mass was diagnosed as cutaneous lymphoma, based on cytologic examination of a mass aspirate and histopathology. Using immunohistochemistry the neoplastic cells were positive for CD3 but negative for CD79a, E-cadherin, and pancytokeratin, confirming their origin as T lymphocytes. No tumor recurrence was noted 18 months after surgery. To our knowledge, this is the first report of a solitary nodular form of cutaneous lymphoma in a young dog.  相似文献   
3.
Pluviographic data at 15 min interval from 6 stations in Pulau Penang of Peninsular Malaysia were used to compute rainfall erosivity factor (R) for the revised universal soil loss equation (RUSLE). Three different modelling procedures were applied for the estimation of monthly rainfall erosivity (EI30) values. While storm rainfall (P) and duration (D) data were used in the first approach, the second approach used monthly rainfall for days with rainfall ≥ 10 mm (rain10) and monthly number of days with rainfall ≥ 10 (days10). The third approach however used the Fournier index as the independent variable. Based on the root mean squared error (RMSE) and the percentage error (PE) criteria, models developed using the Fournier index approach was adjudged the best with an average PE value of 0.92 and an average RMSE value of 164.6. Further, this approach was extended to the development of a regional model. Using data from additional sixteen stations and the Fournier index based regional model, EI30 values were computed for each month. ArcView GIS was used to generate monthly maps of EI30 values and also annual rainfall erosivity (R). The rainfall erosivity factor (R) in the region was estimated to vary from 9000 to 14,000 MJ mm ha− 1 h− 1 year− 1.  相似文献   
4.
Striped hyena(Hyaena hyaena) is a near-threatened large carnivore known to occur in arid and semi-arid landscapes in many parts of the world. Its population is declining globally and ecological information is required urgently to meet their conservation needs. We studied the diet pattern of the striped hyena in the semi-arid Gir National Park and Sanctuary(GNPS), western India. Prey items eaten by the striped hyena were identified from scats. Around 44.4% scats represented single to three mammalian preys while 55.6% of them represented four preys to seven preys. A variety of food items were identified including mammals, birds, insects and vegetable matters. Scats analysis showed that 63.91% diet of striped hyena was contributed by wild prey items, 20.94% by domestic prey and 3.31% by birds, whereas vegetable and insects contributed 9.92% and 1.93%, respectively. Diet diversity of the striped hyena computed by the Shannon-Weiner Index(H) was found to be 2.64. The presence of domestic mammals in the scat remains implied that the striped hyena might frequently visit human habitation in search for food and hence, a potential conflict between human and wildlife might arise. Reducing the dependence of hyena on domestic livestock is a challenge to ensure the survival of striped hyena outside the protected area.  相似文献   
5.
Long-term data are given on priority directions in apple breeding: for an increased content of biologically active substances in fruit and for scab resistance. The high effectiveness of apple breeding at the polyploid level is shown.  相似文献   
6.
Betaine is found ubiquitously in plants, animals, microorganisms, and rich dietary sources including seafood, spinach, and wheat bran. The chief physiological role of betaine is to function as a methyl donor and an osmolyte. Betaine also acts as an osmolyte, to maintain the avian’s cellular water and ion balance to improve the avian’s capacity against heat stress via preventing dehydration and osmotic inactivation. It helps in maintaining the protective osmolytic activity, especially in heat-stressed birds. Betaine may promote various intestinal microbes against osmotic variations and thus improve microbial fermentation activity. Previous studies showed that dietary supplementation of betaine in poultry diets could positively affect nutrients’ digestibility, reduce abdominal fat weight, and increase breast meat yield. In addition, betaine has been reported to protect internal organs and boost their performance. Its inclusion in poultry diet is sparing essential amino acids like choline and methionine. In addition, it may play an important role in lean meat production by positively affecting the lipid metabolism with increased fatty acids catabolism and thus reducing carcass fat deposition. The aim of this review article was to broaden the knowledge regarding betaine and its importance in the poultry industry to cope with the heat stress problem. Moreover, it should be added to the diet as a natural anti-stressor through different routes (water/feed) to overcome the heat stress problem. However, further studies need to be conducted at the genetic and molecular basis to elucidate the mechanism behind the betaine as a natural anti-heat agent to decrease the heat stress problem in the poultry industry.  相似文献   
7.
The radiosensitivity of uredospores of the stem rust pathogen is studied in a wide range of β- and γ-radiations (14–2500 Gy). It is shown that a change in the degree of infection of plants is related not to loss of virulence of the pathogen but to their genetically determined resistance. The biochemical indices of wheat resistance to the pathogen are determined.  相似文献   
8.
Journal of Crop Science and Biotechnology - India has a diverse range of agro-ecological conditions which support the cultivation of different rice varieties differing in the adaptation which is so...  相似文献   
9.
Buffalo is considered short-day breeder in tropical and subtropical part of the world and seasonality and photoperiodism impart major influence on its fertility. However, its impact on in vitro embryo production (IVEP) remains elusive. Therefore, this study investigated the effect of seasonal variations and photoperiodism on morphological and molecular parameters of IVEP in buffalo. For this purpose, we conducted two different experiments on the oocytes obtained by aspirating follicles from abattoir derived ovaries. In Exp. I, retrospective analysis was performed for oocyte recovery, blastocyst and hatching rate, during four consecutive seasonal periods (i.e. January–March, April–June, July–September and October–December). In Exp. II, oocytes from peak breeding and non-breeding seasons were subjected to 24 hr in vitro maturation and evaluated for polar body extrusion to assess maturation rate. Results showed that embryo development was markedly low during second quarter (April–June) and maximum during fourth quarter (October–December) of the year; referred as non-breeding and breeding seasons, respectively. Comparative data analysis demonstrated that poor oocyte quality is major reason for lesser efficiency of embryo production during non-breeding season than peak breeding season as suggested by poor oocyte recovery (2.31 ± 0.10 vs. 3.65 ± 0.27) and maturation rate (33.32 ± 2.1 vs. 63.15 ± 7.31). Subsequently, comparative gene expression analysis of blastocysts during peak breeding season significantly upregulated pluripotency gene (OCT-4) and downregulated heat shock protein 90, as compared to non-breeding season. Therefore, it could be divulged from the present study that seasonal variations and photoperiodism have profound effect on oocyte quality and subsequent embryo development. It is recommended to find suitable additives for in vitro maturation that could mitigate seasonal effects.  相似文献   
10.
ABSTRACT

The present investigation was based on the hypothesis that the endophytes residing in the roots of halophytes have better adaptation to saline conditions. Six halophytic herbs were collected from Khewra salt range (EC = 4.7 dS m?1 and SAR = 25.7). From these herbs, root pieces of Cenchrus ciliaris were shade dried; finely ground to powder and three plant growth promoting rhizobacteria (PGPR), Bacillus cereus, Pseudomonad moraviensis, and Stenotrophomonas maltophilia, were isolated. Root powder in sterilized and unsterilized forms was added in the saline-sodic field on wheat and mixed with soil in pot experiment with induced NaCl (150 mM). Sterilized root powder increased organic matter NO3-N and P contents of soil and leaves, fresh weight, sugar content, and yield attributes. The root powder application in unsterilized form significantly decreased EC, SAR, and Na content of field soil with concomitant increase in soil and leaves K, P, and NO3-N. The farmer’s benefit was increased by 33% at yield. Root powder-induced salt tolerance was mediated by the PGPR (residing inside the root) through increased growth and better physiological adaptations. It is inferred that root powder harboring the PGPR may be an alternative to biofertilizer with longer shelf life and may also serve as carrier for the preparation of effective biofertilizer for saline land using other PGPR bio-inoculants.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号