发展退耕还林工程建设之我见

退耕还林工程的实施,不仅增加了林草植被,加快了国土绿化进程,减轻了水土流失和风沙危害,而且促进了农村产业结构调整,加快了农村劳动力转移和城镇化建设进程,增加了农民收入,也有力地推进了新农村建设。 一、退耕还林工程取得的显著成效 1.加快了生态建设步伐 退耕还林工程从2002年实施以来,为我市生态建设增添了强有力的动力。退耕还林工程的实施,增加了林草植被,有效地控制了工程区的水土流失和土地沙化、退化,保护了农田牧场的安全,增加了土壤蓄水保水能力,提高了抗御自然灾害的能力,生态环境得到明显改善。     

加强农民合作社建设 促进农村经济大繁荣

多年的实践证明,专业合作社整合了同类资源实行联合,提高了农民生产经营的组织化程度,形成了拳头效应,变一家一户的分散经营为联合经营,提高了市场竞争力和市场占有率,增强了抵御风险的能力,降低了生产成本,提高了经济效益。农民合作专业社的成立,加强了服务功能,带动了乡镇、县市区乃至全国的交流与合作,显示了强大的优越性,为社会主义新农村建设起到了积极的作用。     

基于温度场的三维复杂槽型铣刀片的槽型重构技术

对三维复杂槽型温度场做了分析,建立了基于ANSYS的铣刀片有限元模型,确定了边界条件。对于给定的边界条件进行了数据处理,得出了关键热源点上的温度值。分析了刀具几何参数的影响并优化了参数选择,在此基础上,做了槽型优化和重构,并进行了验证。     

农资·电商序曲

<正>电子商务来了十几年了,一浪涌来,先是淘宝出世,改变了商业生态,卖的方式变了,买的习惯也变了;当当上线,改变了书市的格局,书店稀缺了,书价平民了;滴滴驾临,改变了出租车市场的混乱,行车规范了,打车方便了。这都是电商的魅力。一波浪潮过后,又一波浪潮到来,农业也终于打破寂寞,生鲜方兴未艾,农资就粉墨登场了。最早的农资电商不可考,率先高调亮相的是2013的农一网,紧接着优种网、云农场等一起出场了。     

大力推广水稻现代农艺技术 稳定提高粮食生产水平

闵行区农业加大科技自１９９３－１９９９年的７年间,全面推广水稻现代农艺技术,取得了较好的社会,经济效益,首先基本解决了粮农的“三弯腰”困苦,解放了生产力,从而推动了农村经济的发展。其次,节省了用地,减少了成本,提高了单产,促进了农民增产增收,从而调动了农民的种粮积极性。     

乌珠穆沁羊选育研究

本课题通过七年的大量研究工作和现场选育,已园满完成了研究方案规定的任务羊群有了根本好转,血液纯化了,优良基础保留下来了,毛色整齐了,类型一致了,品质提高了,羊群的遗传性较前稳定了。七年来选育出优良种羊8万只,完成了有关乌珠穆沁羊选育方面论文和研究报告100多篇。这项研究成果不仅为生产提供了优良种羊,而且为今后进一步提高创造了良好的条     

如何养植盆栽吊兰

观察叶子的颜色等状态,就知道吊兰的生长状况:是水浇过头了,还是缺水了;是受冻了,还是受热了;是光照强了,还是光照弱了;是肥过剩了,还是缺肥力;是得病了,还是生虫了。及时调整生境,使植物按照自身的生物学特性健康生长。     

广东东莞市4种典型生态农业模式的结构与效益分析

对东莞市４种典型的生态农业模式的结构与效益进行了分析,研究表明：４种模式均取得了良好的社会、经济和生态效益,为社会提供大量的宵产品,使经营者了省了不少生产费用创造了较高的纯收入,提高了资源的利用效率,改善了生态环境,增强了人们保护环境、热爱大自然的意识。     

多机协同多目标攻击系统研究

研究了多机协同多目标攻击系统,定义了自主优先权,提出了分组决策的方案,设计了目标分配和火力分配的原则,采用神经网络实现了决策算法,并对整个决策系统进行了仿真;阐述了导弹攻击区的计算方法,用比例导引法实现了空空导弹攻击。最后设计了多目标攻击系统,将空战决策,导弹攻击区判断,导弹攻击融为一体,并进行了仿真。结果验证了空战决策的正确性。它对第四代歼击的火力控制系统的研究有一定的参考价值。     

再谈杂交水稻种子的市场竞争

杂交水稻种子依据《种子法》打破了市场长期垄断的局面,引入了竞争经营机制,形成了百花齐放、百家争鸣、前所未有的繁荣局面,加快了先进科技成果的转化,加快了新品种(组合)的研发创新速度,促进了种子质量和稻米品质不断提高,推动了售后服务的开展和新技术推广,促进了产业化和“     

Exploiting tolerance processes in transplantation

The full potential of organ transplantation has not yet been realized because of the hazards associated with the long-term use of immunosuppressive drugs. Modern research into mechanisms of immune tolerance offers the promise of reprogramming the immune system, so as to harness the body's natural tolerance mechanisms in the service of graft acceptance. This would allow the minimization of immunosuppressive treatment and offers the prospect of eventually weaning transplant recipients off their drugs.     

THYMECTOMY: PROLONGATION OF IMMUNOLOGICAL TOLERANCE IN THE ADULT MOUSE

The loss of acquired immunological tolerance of mice to bovine gamma globulin depended on the presence of the thymus. Mice were repeatedly injected with bovine gamma-globulin from birth until the age of 5 to 10 weeks and then thymectomized or sham operated. After 130 to 160 days without antigen, an accelerated (immune) disappearance of I(125) bovine gamma-globulin could be uniformly induced in controls while thymectomized mice remained tolerant. Adult thymectomized mice made tolerant by a single injection of bovine gamma-globulin lost tolerance more slowly than sham-operated controls.     

Fetal and adult hematopoietic stem cells give rise to distinct T cell lineages in humans

Although the mammalian immune system is generally thought to develop in a linear fashion, findings in avian and murine species argue instead for the developmentally ordered appearance (or "layering") of distinct hematopoietic stem cells (HSCs) that give rise to distinct lymphocyte lineages at different stages of development. Here we provide evidence of an analogous layered immune system in humans. Our results suggest that fetal and adult T cells are distinct populations that arise from different populations of HSCs that are present at different stages of development. We also provide evidence that the fetal T cell lineage is biased toward immune tolerance. These observations offer a mechanistic explanation for the tolerogenic properties of the developing fetus and for variable degrees of immune responsiveness at birth.     

HSP70/HSP27对免疫细胞保护作用的研究进展

热休克蛋白（Heat shock proteins,HSPs）作为一类重要的非特异性细胞保护蛋白,在免疫细胞应激耐受和应激保护中发挥着重要作用,其分子伴侣和抗细胞凋亡作用对于维持免疫细胞生存和内环境的稳定具有重要意义.热休克蛋白70（HSP70）和小分子热休克蛋白（Small heat shock proteins,sHSPs）中的HSP27是HSPs家族中的重要成员,也是近年来被广泛关注的研究对象,已经证实在参与调解细胞的增殖、分化和细胞凋亡过程中起到重要的作用.文章就HSP70/HSP27在热应激条件下对免疫细胞的保护作用进行了综述,对该领域中存在的问题进行了回顾,并对其发展前景进行了展望.     

Immunologic tolerance: collaboration between antigen and lymphokines

Immunologic tolerance is the process whereby limits are placed on the degree to which lymphocytes respond to an animal's inherent antigens. It is a quantitative rather than an absolute term, as some autoantibody formation is common. Contrary to early hopes, it is not due to some single, simple causative mechanism confined to early developmental stages of the fetal immune system. Rather, self-tolerance results from a variety of complementary mechanisms and feedback loops in the immune system and is thus best seen as part of the general process of immunoregulation.     

T cell-independent rescue of B lymphocytes from peripheral immune tolerance

Autoimmunity arises when immune tolerance to specific self-antigens is broken. The mechanisms leading to such a failure remain poorly understood. One hypothesis proposes that infectious agents or antigens can break B or T lymphocyte self-tolerance by expressing epitopes that mimic self. Using a transgenic immunoglobulin model, we show that challenge with self-mimicking foreign antigen rescues B cells from peripheral tolerance independent of T cell help, resulting in the accumulation of self-reactive cells in the lymph nodes and secretion of immunoglobulins that bind to a liver-expressed self-antigen. Therefore, our studies reveal a potentially important mechanism by which B lymphocytes can escape self-tolerance.     

Disease tolerance as a defense strategy

The immune system protects from infections primarily by detecting and eliminating the invading pathogens; however, the host organism can also protect itself from infectious diseases by reducing the negative impact of infections on host fitness. This ability to tolerate a pathogen's presence is a distinct host defense strategy, which has been largely overlooked in animal and human studies. Introduction of the notion of "disease tolerance" into the conceptual tool kit of immunology will expand our understanding of infectious diseases and host pathogen interactions. Analysis of disease tolerance mechanisms should provide new approaches for the treatment of infections and other diseases.     

转基因作物饲用安全性评价研究进展

通过引入外源基因的途径对农作物进行遗传改良,转基因技术已经在作物的抗虫、抗除草剂、抗病、抗旱等方面显现出了巨大的潜力。2013年全球转基因作物种植面积已经比1996年首次种植面积增长了100多倍,达到1.75亿hm²,转基因作物及其副产品大部分则用于动物饲料原料,因此,转基因饲料中外源基因和外源蛋白在畜禽体内消解和转移规律以及转基因成分对畜禽营养、生长、健康等方面的影响是社会关注的焦点。笔者在提出转基因作物饲用安全性评价的紧迫性和必要性的基础上,特别指出转基因作物饲用安全性评价与食用安全性评价的特殊性;讨论和分析转基因作物评价所应该遵循的科学原则;概述抗虫作物、抗草甘膦作物和转植酸酶基因玉米中转基因成分的特性;侧重分析了饲料中转基因成分在畜禽体内的消解、转移,转基因饲料的营养价值和饲料养分效价评定,重点剖析转基因饲料对畜禽营养、免疫、繁殖和肠道微生态影响的研究进展。从短期、长期和多代效应综合分析转基因饲料的安全性,转基因饲料中外源基因和外源蛋白未发现从饲料中转移到畜禽组织、器官和血液中,仅少量残存于消化道前段的食糜中;转基因饲料也没有对畜禽营养、免疫、繁殖、肠道健康产生不利作用。但目前还需深入探讨试验材料的选择和相关信息的准确描述、转基因成分在畜禽体内的消解和转移的方法、转基因饲料对畜禽繁殖、免疫以及长期多代的作用研究,以期为建立和完善转基因饲用安全评价体系提供参考。     

中草药饲料添加剂在畜禽上应用研究进展

目前,全世界正在兴起一场绿色生态农业革命,中草药制剂在促进动物生长和提高动物免疫功能方面具有独特优势,合理搭配使用对动物无任何毒副作用。中草药饲料添加剂作为一种纯天然的绿色添加剂,是一种既无抗药性和耐药性,也无药害残留、无污染的一类天然产品,具有抗病保健、抗毒素、提高机体免疫力和生产性能、调整胃肠机能等特点。主要阐述了中草药饲料添加剂对畜禽生长、免疫、消化酶活性和肉质品质的影响,可为中草药添加剂在饲料中的合理应用提供理论依据。     

纯种和杂种山羊红细胞上C_(3b)受体的研究

本研究通过71例纯种杂种山羊血液的检测,发现山羊的红细胞上除具有粘附作用,形成免疫复合物花环外,还具有C_(3b)受体花环.从而证实,山羊的红细胞不仅具有携带、运输气体和调节体内酸碱平衡的功能,而且还具有重要的免疫功能.同时发现,杂种山羊红细胞上C_(3b)受体花环率的均值,显著高于纯种山羊(p<0.01).因此,我们初步认为,杂种山羊表现的适应性和抗病力强等杂种优势,除与遗传因素有关外,可能还与红细胞上C_(3b)受体花环率高有关。