The rise and fall of public sector plant breeding in the United Kingdom: a causal chain model of basic and applied research and diffusion

This paper examines the barley and wheat breeding programmes of the Plant Breeding Institute (PBI), which was the most successful public plant breeding institute in the UK, until privatization in 1987. The PBI's shares in barley and wheat seed sales are explained, showing that the success with barley was largely a matter of serendipity, whereas the wheat programme followed a more normal pattern. For wheat, the causal chain, or recursive, model decomposes the well-documented link between research expenditures and increases in agricultural productivity into three stages. These are the effects of R&D expenditures on basic research output, measured by publications, the effect of publications and applied R&D expenditures on trial plot yields, and the diffusion of the trial plot technologies, which raises yields on farms. Applying the model to the FBI's wheat varieties allows estimation of the lag structures. In contrast to the results for aggregate agricultural research, for a single plant breeding programme alone there is a considerable lead time before there is any response, followed by a lag distribution only a few years long. The returns to the R&D investments are calculated from the causal chain model, from single equation estimates and by evaluating the yield advantage of the PBI varieties. All three approaches give consistent results, which show that the returns to barley and wheat alone were sufficient to support the entire PBI budget and still give rates of return to applied research of between 14 and 25%. The return to the basic science expenditures of the John Innes Institute has a lower bound of 17%, but must have been even higher than for the PBI if the other Institutes were taken into account. The paper concludes by commenting on the effects of the privatization of the PBI.     

The effect of involvement on visual attention and product choice

Our study examined the effect of consumers' level of involvement on visual attention to product, information sign and price sign guided by the Elaboration Likelihood Model (ELM). We also investigated the relationship between visual attention captured by eye fixation on information and price sign and product choice for garden plants. Using a Tobii X1 light eye tracking device, we obtained data from 101 respondents in Texas and Michigan. We found that participants who had high (vs. low) product involvement paid more attention to the product and its information as demonstrated through higher fixation count (FC), longer total fixation duration (TFD), and total visit duration (TVD). We also found highly involved participants processed price information as a central rather than a peripheral cue. In addition, total visit duration (TVD) on an information sign was found as the strongest predictor of product choice.     

企业质量文化建设探讨

建立质量文化已经成为企业提高外部竞争力和增强内部凝聚力的需要，是适应市场经济发展的需要。更是企业在市场中取得成功的关键。优秀的质量文化能够引导企业走质量经营道路，实现卓越的经营绩效。对济柴质量文化建设的特点进行总结归纳，阐述了济柴下一步质量文化建设的重点，并提出了自己的见解。     

Returns to public sector plant breeding in the presence of spill‐ins and private goods: the case of bean research in Michigan

This article illustrates a methodology for assessing economic returns to a publicly funded breeding program in the presence of private sector investments, and spill‐ins from other contemporary public institutions and past research efforts. The approach consists of determining yield gains from bean improvement research; applying these yield gain estimates to measure benefits attributable to different institutional players and time periods; and then assessing the benefit‐cost ratios of investments in a bean improvement program since 1980 by Michigan State University (MSU). The results indicate that investments in MSU's bean breeding program have yielded benefits to costs ratio in the range of 0.7 to 2.2, depending on the attribution rule used to estimate the benefits. The estimated benefit/cost ratios reported in this study are lower‐bound estimates, as they do not account for potential benefits from area planted to MSU varieties outside of Michigan (spillover effects), which was 1.5 times greater than the area planted to MSU‐bred varieties within Michigan in the period 1998–2002. The implications of the increasingly privatized bean seed markets for the role of public sector research in bean improvement research are discussed.     

低碳背景下农村能源消费结构优化的路径与对策--以河北省为例

随着农村经济发展和农民收入的逐年提高,我国农村居民能源消费在总量上已得到基本满足,但结构亟待优化。农村能源结构调整的最终目标是“去煤化”,即通过发展现代生物质能、太阳能、风能等新能源来替代化石能源。实现这一目标,应根据“因地制宜、多能互补、综合利用、讲求效益”的方针逐步推进。根据河北省目前的实际情况,应把生物质能源的开发利用放在首要地位,其次要加强太阳能的推广和利用,同时优质低硫煤推广工作也应并行展开。     

Harvesting in an integrated general equilibrium model

Harvesting of prey biomass is analyzed in an integrated ecological-economic system whose submodels, a predator–prey ecosystem and a simple economy, are microfounded dynamic general equilibrium models. These submodels are interdependent because the ecosystem responds to harvesting—through the reactions of optimizing individual organisms—by changing the provision of public ecosystem services to consumers. General analytical results are derived regarding the impact of harvesting policies on short-run equilibria of both submodels, on population dynamics, and on stationary states of the integrated model. A key insight is that prey biomass carries a positive ecosystem price which needs to be added as a tax mark-up to the economic price of harvested biomass to attain allocative efficiency. Further information on the dynamics is gained by resorting to numerical analysis of the policy regimes of zero harvesting, laissez-faire harvesting and efficient harvesting.

It “... is a matter of weighing costs and benefits of taking action, whether the action is the “inert” one of leaving resources alone in order to conserve them, or whether it involves exploiting a resource ... for so-called material ends”. Pearce (1976, p. 320)

Helpful comments from an anonymous referee are gratefully acknowledged. Remaining errors are the authors’ sole responsibility.     

植物功能性状对城市湿地水体富营养化的响应研究进展

城市湿地是构成城市复合生态系统重要的生态系统类型,住维持城市生态系统安全方面具有不可替代的作用。城市湿地面临的主要问题之一是水体富营养化,主要是由于人类活动引起的氮、磷元素的过量输入和N：P比例失调所导致的一系列生态问题。从植物全株性状、叶片性状、茎和根性状以及繁殖性状等方面综述了湿地高等植物功能性状对湿地水体富营养化的响应,并展望了今后可能的研究方向。     

三江平原小叶章种群构件的功能动态

小叶章分株高度的季节动态：典型草甸和沼泽化草甸在8月末均达到最大值,沼泽在7月末达到最大值,而后缓慢下降。小叶章种群茎构件和叶构件生物量的季节动态在三个生境中均表现出较一致的变化规律,均自5月末开始,各生境的数量性状逐渐增加,至7月末达到最大值,而后逐渐下降,呈抛物线型。三个生境小叶章分株F/C值均具有相似季节变化趋势。其极大值均出现在7月末,但三个生境之间亦有明显差异, F/C值的整体水平表现为沼泽>沼泽化草甸>典型草甸,其极大值、极小值亦反映出此规律。     

基于Plant Simulation的烟草柔性分拣系统仿真与优化

针对烟草物流配送中心场地限制和分拣效率低下等问题,根据柔性分拣系统的工作原理及流程,运用Plant Simulation仿真软件建立烟草柔性分拣系统模型,设计了条烟自动分拣的虚拟托盘算法。通过仿真分析得到限制其分拣效率的瓶颈工位,利用添加缓存区和增加码垛工位的优化方法对分拣系统进行初步优化,并且从Experiment Manager模块中的单因子多水平试验方法确定了最优缓存区容量。仿真结果表明该优化方法显著提高了分拣效率,使其达到8866.08条/h,是优化前的1.39倍,且缩短了配送时间,能够很好地满足烟草物流配送中心的分拣要求。