Open-design Recirculating Systems for Zebrafish Culture

The zebrafish is an established vertebrate-animal model in biomedical research. Currently, their mass culture is mainly done using systems provided by commercial suppliers. Commercial systems are compact, recirculating, and use auto-cleaning tanks. These features minimize space use, labour cost, and water wastage; thus, facilitating maintenance of a large number of zebrafish using minimal resources. However, the often considered costs associated with these systems often impose a barrier to current and prospective researchers, especially those with limited funds or working in labs with no access to institutional centralized zebrafish culture facilities. In contrast to commercial systems, custom-made zebrafish maintenance systems are also described in the literature. To distinguish custom-made system from commercial systems, we termed them as “open-design” systems. Open-design systems are cost-effective, modular, and frequently being improved by zebrafish researchers. However, for further development and to present them as a viable option for zebrafish researchers around the world, a review of their current status and technical understanding is required. Here, we compile the disparate data on the purpose and technological development of the open-design systems. We believe this review will be a valuable resource for all zebrafish users and help streamline the open-design technology for zebrafish culture.     

Studies on Tomato Seedling Quality Indices Under Simulated Shipping and Storage Conditions

Indices of the tomato seedling quality maintenance level after production before field planting were studied through simulated experiments, small--scale operation, indoor analyses and measurements, and field observation. The results showed that under simulated shipping and storage conditions, seedling quality change following different durations (days) of shipping and storage was correlated significantly or even very significantly with certain physiological and morphological indices. With various measured indices following different periods of shipping and storage treatment subjected to multinomial successive regressive correlation analysis, the principal factors influencing seedling quality maintenance level are identified to be chlorophyll content→dry short weight→ leaf freshness index in order of their importance. Significance analysis with multinomial fitted equation indicated that correlations between any one of above three factors and the growth index after field planting reached very significant difference level.     

国内高架桥绿化及研究现状

从高架桥区的生态环境、适生种类的选择以及高架桥绿化的养护管理、景观配置模式四个方面对国内的高架桥绿化及研究现状进行了分析和探讨,指出了存在的问题和解决方法,并对高架桥绿化的前景进行了展望.     

钢管混凝土拱桥的施工监控技术

钢管混凝土是由混凝土填入薄壁钢管而形成的一种组合材料。在桥梁结构上,钢管混凝土主要应用于拱桥。目前,大跨度钢管混凝土拱桥主要采用缆索吊装-斜拉扣定施工新技术,拱桥的线形通过实测每节钢管拱的标高及拱轴线位置,并借助扣索实施动态调整来保证。为此,介绍了钢管混凝土拱桥施工过程的监控技术,从而指导施工,以确保拱桥建成后满足设计要求。     

农机监理计算机管理系统维护案例分析

对使用Windows 2000 Server操作系统，以及MS SQL Server数据库的农机监理计算机管理系统的维护，进行了较为详细的分析，并针对不同的情况提出了相应的处理措施，总结了保证农机监理系统可靠运行的办法。     

ERP系统中设备维修计划的研究

在制造企业设备的使用过程中,设备维修计划成了各种设备管理系统所公认的管理重点,这就更需要设备维修活动在企业内部能形成一个有计划、有步骤的活动。为此,简要介绍了作为ERP管理系统中的子系统一设备管理系统的主要目标,着重讨论了设备管理系统的管理重点一维修计划新思想的形成以及制定维修计划的步骤。     

Using the indicator amino acid oxidation technique to study threonine requirements in horses receiving a predominantly forage diet

Threonine has been reported to be the second limiting amino acid in typical equine diets, but its actual requirement has not been determined in horses. To evaluate amino acid metabolism and requirements, the indicator amino acid oxidation (IAAO) method has been successfully used in other species. The objective of this research was to estimate threonine requirements in mature horses fed timothy hay and concentrate in 4:1 ratio using the IAAO method. Six Thoroughbred mares (579.9 ± 46.7 kg) received each of 6 levels of threonine intake, 41, 51, 61, 70, 80 and 89 mg/kg BW/day, in a randomly determined order. Each study period was 7‐day long, and on day 6, blood samples were collected before and 90 min after feeding to measure amino acid concentrations using HPLC. On day 7, horses underwent IAAO procedures, which included a 2‐hr primed, constant intravenous infusion of [¹³C]sodium bicarbonate to measure total CO₂ production and a 4‐hr primed, constant oral administration of [1‐¹³C]phenylalanine to estimate phenylalanine oxidation to CO₂. Blood and breath samples were collected to measure blood [¹³C]phenylalanine, using GC‐MS analysis and breath ¹³CO₂ enrichment, using an infrared isotope analyser. Increasing threonine intake levels did not affect plasma phenylalanine oxidation by the ANOVA test (p > 0.05) but resulted in a linear decrease in phenylalanine oxidation (p = 0.04) without a breakpoint by the orthogonal linear contrast. This study is the first attempt to evaluate threonine requirements in horses by the IAAO method; however, threonine requirements are still unknown in mature horses at this time.     

威信农业机械维修网点建设对策

文章结合威信县农机维修网点的发展现状,分析威信县农机维修网点在发展中存在的问题,提出促进威信县农机维修网点建设的发展建议。     

绿地养护的原则及方法和途径

绿地养护是绿化得以存续、发展的根本保证,应遵循及时、适度和系统5条原则,采用现场观测法、理论指导法和经验操作法;从灌溉(排涝)、有害生物防治、施肥、整形修剪、清除杂草和垃圾、更新补植、维护设施、协调及创新9个途径开展工作.