开发城市地下空间前景广阔

本文介绍了开发城市地下空间的必然趋势及前景，阐明开发利用城市地下空间，对节省城市用地、节约能源、改善城市交通、减轻城市污染等都有着重要作用。     

20世纪80年代以来世界除草剂新品种开发进展及特点(一)

综述了近20年来世界除草剂新品种的开发进展，并介绍了除草剂工业发展的一些新特点。     

陕西苹果产业SWOT分析及发展策略

在分析陕西苹果产业的优势、劣势、机会、挑战的基础上,提出扩张发展型、竞争型、防御型、保守型4种战略方案。     

宜宾竹业发展战略初探

竹业是宜宾地区经济发展的一个重要产业,起步早、发展较快,但机械化程度不高,产品技术含量低,加工力量分散,形不成规模生产。为振兴宜宾竹业,本文就加快竹浆造纸支柱产业发展、建立竹业开发集团、建立西南最大的竹种园方面进行了发展战略探讨。     

灌溉对白三叶生殖生长及种子产量和质量的影响

白三叶(Trifolium repens L.)是温带重要的豆科牧草,在我国草地改良及生态环境建设中具有重要作用。而目前我国白三叶种子主要依靠进口,其生产研究匮乏、技术落后,使之生产利用受到严重制约。本研究以白三叶海法品种为对象,于2003年11月-2005年6月在云南省种羊场,采用随机区组试验设计,设置5个水分调控处理;结合室内土培法,通过对白三叶种子田需水量及灌水时间的确定,水分对白三叶种子产量及产量构成要素的影响、对营养生长与生殖生长的调控、对种子发育及种子质量的影响等方面研究其种子生产的高产灌溉制度,并从生理生化的角度研究水分对白三叶生长发育的调控。     

Quantitative and descriptive histological aspects of jaguar (Panthera onca Linnaeus, 1758) ear skin as a step towards formation of biobanks

Skin of mammals vulnerable to extinction, such as the jaguar, is used as a source of material in conservation strategies. The composition of skin is not uniform among species, and the ability to distinguish similarities in skin morphology in animal groups is fundamental in the application of skin tissue for use in biobanks. The aim of our study was to evaluate the structure, composition and capacity for culture of ear skin from the yellow and black jaguars. Both qualitative and quantitative methods were used, focusing on skin thickness, cell quantification and distribution, collagen density, proliferative activity and viability. Histomorphometrical study of the skin showed a total thickness of 273.2 and 274.6 µm for the yellow and black jaguars, respectively. Melanocytes and fibroblasts were, respectively, 9.7 and 23.0 for the yellow jaguar and 11.3 and 26.8 for the black jaguar. A collagen density of 67.0% and 49.0% was observed for yellow and black jaguars, respectively. Both animals presented a proliferative activity varying between 1.20 and 1.30. All tissues could promote cellular detachment, reaching subconfluence in 10–15 days. This kind of information from histomorphometrical features and cell cultures can be essential for a more targeted application of ear skin cryopreservation in this species, as such information will enable understanding the action of substances on tissues during the conservation process.     

初产牛乳腺炎研究进展

奶牛乳腺炎是由多种因素引起的严重影响奶牛业发展的重要疾病,初产牛临床和亚临床乳腺炎的流行和发病率,尤其在泌乳初期,均高于经产母牛.初产牛与经产牛的流行病学和危险因素不尽相同,为更加有效地控制初产牛乳腺炎,必须对初产牛乳腺炎进行深入系统的研究.论文重点论述了初产牛产前和产后临床、亚临床乳腺炎患病率和发病率,乳腺炎的致病因素,病原和诊断技术,介绍了国内外初产牛乳腺炎兽医防治、抗病育种等方面的研究成果.     

A dynamic, optimal disease control model for foot-and-mouth disease: I. Model description

A dynamic optimization model was developed and used to evaluate alternative foot-and-mouth disease (FMD) control strategies. The model chose daily control strategies of depopulation and vaccination that minimized total regional cost for the entire epidemic duration, given disease dynamics and resource constraints. The disease dynamics and the impacts of control strategies on these dynamics were characterized in a set of difference equations; effects of movement restrictions on the disease dynamics were also considered. The model was applied to a three-county region in the Central Valley of California; the epidemic relationships were parameterized and validated using the information obtained from an FMD simulation model developed for the same region. The optimization model enables more efficient searches for desirable control strategies by considering all strategies simultaneously, providing the simulation model with optimization results to direct it in generating detailed predictions of potential FMD outbreaks.     

The face of conservation responding to a dynamically changing world

In its 40‐year history, the science of conservation has faced unprecedented challenges in terms of environmental damage and rapid global change, and environmental problems are only increasing as greater demands are placed on limited natural resources. Conservation science has been adapting to keep pace with these changes. Here, we highlight contemporary and emerging trends and innovations in conservation science that we believe represent the most effective responses to biodiversity threats. We focus on specific areas where conservation science has had to adjust its approach to address emerging threats to biodiversity, including habitat destruction and degradation, climate change, declining populations and invasive species. We also document changes in attitudes, norms and practices among conservation scientists. A key component to success is engaging and maintaining public support for conservation, which can be facilitated through the use of technology. These recent trends in conservation and management are innovative and will assist in optimizing conservation strategies, increasing our leverage with the general public and tackling our current environmental challenges.