美国高校社会服务工作对我国高校草坪科学学科建设的启示

除了教学和科研工作外,大部分美国高校对农业类学科包括草坪学科的专业师资在职责要求方面还有重要的一项-"Extension",即社会服务。社会服务的工作量因人而异,但总体来看基本都做到了"分配到人";除了专业教师,学校对于学生也要求或鼓励其参与各类校内外拓展活动。这与我国高校教师社会服务(或专业拓展)工作,以及基于此提出的"产学研"等类似的工作模式都有较大不同。草坪科学是一门新兴的学科,应用性较强,知识生产和知识创新都离不开实践。因此从学术驱动的内因和大学的价值来讲,大学的社会服务工作是极其重要的。本文简略介绍美国高校草坪科学教师的社会服务工作情况,希望能够对我国的草坪科学学科建设以及师资组建和培养提供参考。     

农业科技对粮食生产的贡献现状及对策

[目的]促进粮食持续稳定地增长,保证国家粮食安全。[方法]调查分析保山市隆阳区瓦马乡2004—2008年农业科技对粮食生产的贡献。[结果]结果表明,农业科技对粮食生产贡献大,与发达地区差距不小,增产潜力大。[结论]提出了粮食进一步增产的科技对策。     

Characterization and growth conditions of Vibrio parahaemolyticus strains with different virulence degrees that cause acute hepatopancreatic necrosis disease in Litopenaeus vannamei

The phenotypic characteristics and growth kinetics at several temperatures, salinities, and pH values of three Vibrio parahaemolyticus (Vp) strains with different virulence and one nonpathogenic strain were evaluated. Independent of the virulence of the strain, a high metabolic diversity was found, which yielded different colored phenotypes on the CHROMagar? Vibrio. All strains were resistant to ampicillin and carbenicillin, and Vp AHPND+ organisms were the most sensitive to enrofloxacin. The exponential growth of Vp strains started at 1–2 hr of incubation, although no relationship was observed between the bacterial density and degree of virulence. Moreover, the growth of the most virulent strain was independent of the nutrients in the incubation media during the initial hour postinoculation. No strain grew at 4°C in 0% NaCl and pH 4, but only Vp AHPND+ grew at 44°C. For all strains, the lag phase was proportional to the NaCl concentration, and the growth was better at pH 8–9. However, the Vp AHPND? strain displayed a greater variability, was more sensitive to extreme conditions, and showed a lag phase of 9 hr independent of the pH.     

Chronological age and reservoir characteristics as predictors of trait composition in Neotropical reservoir fish assemblages

One of the main impacts on aquatic environments is the alteration of flow regime, usually caused by dam construction. This impact changes the dynamics and functioning of the environment. We aimed to evaluate changes in the composition of functional traits of fish assemblages from 29 reservoirs of different chronological ages. We assessed if there were any alterations in trophic state of these reservoirs according to their ages (chronological variable). Then, we evaluated the relationship between functional traits and environmental/chronological variables. Results showed that reservoir age is a predictor of fish assemblage functional traits composition. In older reservoirs, there was a predominance of omnivorous species, with multiple spawning and parental care. However, herbivorous species, with total spawning and medium size, had their abundance reduced. Also, it was possible to identify the influence of depth and water retention time on the composition of functional traits. By showing that although age has an influence on composition, the intrinsic characteristics of each reservoir are very important in evaluating the impacts of these projects. Therefore, the findings presented provide insights into what may happen to functional traits of fish assemblages with ageing of reservoirs.     

农业科研院所科技开发模式及对策分析——以中国热带农业科学院热带作物品种资源研究所为例

简述中国热带农业科学院热带作物品种资源研究所科技开发的模式与成绩，分析存在的困难和问题，提出加强科技开发的思路和对策。     

青藏高原放牧高寒草甸主要温室气体通量及其主控因素研究

在青藏高原高寒草地不同放牧强度区设4个试验样地,分别为原生草甸(NM)、轻度退化草甸(LM)、中度退化草甸(MM)和重度退化草甸(HM),监测草地温室气体通量。结果表明:不同放牧强度对草地温室气体通量影响显著,放牧活动对高寒草甸的影响首先表现在植被上,而土壤环境的变化比较迟滞。通过逐步回归分析和因子拆分得知,草甸甲烷通量影响较大的环境因素为土壤紧实度和有机质,分别能解释44.6%和28.4%的总变异,CO2通量影响较大的环境因素为紧实度和生物量,分别能解释36.1%和32.8%的总变异,氧化亚氮通量影响较大的环境要素为紧实度和有机质,分别能解释50.1%和22.9%的总变异,家畜的践踏作用使退化草地紧实度增加,进而引起温室气体通量的改变,高寒草甸退化演替发展到重度退化阶段时释放大量温室气体。     

环境因素对羊繁殖性能影响的研究

在现代化的养羊业中,环境因素对羊的繁殖等生产性能造成的影响不可忽视,高温对羊性细胞生成、受精卵发育、内分泌和妊娠等方面危害性最大,其他因素也不容小觑。文章从空气温度、湿度对母羊发情受胎和公羊精子品质的影响,光照对母羊发情排卵及其他生殖激素的影响,饲养密度对羊繁殖性能的影响以及空气中有害气体对羊的危害和防治措施等方面进行简要介绍,以期在生产中改善环境条件,提高羊的繁殖效率。     

许昌市龙跃肉牛养殖公司健康发展启示及建议

许昌市龙跃肉牛养殖公司是一家集养殖、种植、屠宰、餐饮、销售为一体的循环发展肉牛养殖公司,该公司充分利用当地农作物秸秆资源丰富的有利条件,降低生产成本,提高了企业市场竞争力。     

饲料产业的环保问题及解决对策

在过去较长的时间段里,一些畜牧养殖业为了追求规模和经济效益,选择以牺牲环境为代价的生产管理模式。该模式虽然在短期内可以达到明显成效,但其带来的环境污染、食品安全、价格持续走低等问题日益显现,对畜牧养殖业健康、可持续发展形成威胁和挑战。饲料与食品均为可食之物,两者无明显界定,如小麦、玉米等即可作为动物饲料,又可以作为食品,而且诸多食品又来源于动物组织以及蛋和奶。所以,饲料产业与环境、食品安全息息相关。为便于论述,笔者从畜牧养殖业的角度来对饲料产业的环保问题及解决对策做出分析,为有关企业、部门提供参考。