传统酱菜中降解亚硝酸盐枯草芽孢杆菌的筛选和鉴定

酱菜是我国传统风味的调味佳品,但在酱菜的生产过程中易产生大量的亚硝酸盐,因此从酱菜中分离、筛选出能降解亚硝酸盐的高效菌株尤为重要。本实验利用传统分离纯化方法从酱菜中筛选出的能高效降解亚硝酸盐的菌种,并通过现代分子生物学鉴定方法对其进行分析。结果表明,该筛选出的菌株具有一定的降解亚硝酸盐能力,通过分子生物学鉴定为枯草芽孢杆菌。研究为酱菜生产提供优质菌种资源奠定了一定的基础。     

Non‐Governmental Public Norm Enforcement in Large Societies as a Two‐Stage Game of Voluntary Public Good Provision

In small groups, norm enforcement is achieved through mutual punishment and reward. In large societies, norms are enforced by specialists such as government officials. However, not every public cause is overseen by states, for instance those organized at the international level. This paper shows how nongovernmental norm enforcement can emerge as a decentralized equilibrium. As a first stage, individuals voluntarily contribute to a nongovernmental agency that produces an incentive system. The second stage is the provision of a public good on the basis of private contributions. The incentive system increases contributions by means of public approval or disapproval of behavior. It is shown that, even in large populations, nongovernmental norm enforcement can be supported in a noncooperative equilibrium of utility‐maximizing individuals. This result is in sharp contrast to those obtained in the standard situation of voluntary provision of an intrinsic public good which—without altruism or related motives—is eroded by free‐riding. Reliance on altruistic behavior is not required in supplying the second‐order public good “norm enforcement” in large societies.     

Amenity driven price effects and conservation reserve site selection: A dynamic linear integer programming approach

Most conservation reserve design models presented in the literature are static and ignore the dynamic economic aspects of site selection. Typically conservation programs operate under time-related (e.g. annual) budgets and purchase land over time in a sequential manner. The uncertainty of land development has been incorporated in a few dynamic reserve selection formulations using stochastic dynamic programming. However, the existing formulations do not explicitly deal with inter-temporal price and location linkages. We address this issue here and present a two-period linear integer programming model for conservation reserve design that incorporates amenity driven price feedback effects inherent in the reserve development problem. In addition, the model includes spatial and ecological criteria. We then use this model to answer the question “How suboptimal is ignoring amenity driven price effects in reserve design models?” We apply the model to artificially generated data sets and compare the results with the results of an iterated static model that considers only one period at a time. We find that the dynamic model with price feedback effects selects sites at a lower per-site cost. The policy implication of this finding is that conservation programs should avoid purchasing land in the same neighborhood over multiple time periods.     

Marketing “Frankenfood”

ABSTRACT

Most visual package research in marketing to date tests only the main effects of certain visual package elements in artificially isolated experimental contexts, though, in the store, these elements are presented to the shopper in active visual circumstances. Most food packages are highly cluttered with a number of visual and text elements all competing for the shopper's limited attention; this calls into question the external validity, and therefore the usability for practitioner purposes, of these results. Given that marketers often rely on a single visual element as the sole carrier of some particular promotional message, it is critical to ascertain whether single visual elements can break through such visual clutter to effectively deliver their promotional messages to the shopper. In this study, we manipulate the level of background activity of packages while testing the ability of one visual package element—its overall shape—to affect one particular piece of package information of concern to food shoppers— appearance of size or volume. Surprisingly, our results show that the main effect of package shape type on volume perception not only remains robust under visually cluttered conditions, but that the effect is actually heightened for certain, more geometrically complex package shape types. Managerial implications are discussed.     

产业集聚与环境依赖对文化产业效率的影响

文化产业本身既蕴含新兴产业又包含传统业态,这种特征决定了其未来增长路径的复杂性。产业集聚程度是产业效率的重要影响因素,产业效率是产业竞争力的重要体现,而文化产业的集聚效应表现尤为突出。理清文化产业集聚程度与文化产业发展效率之间的作用机理,有助于促进区域文化产业的发展和竞争实力的提升,对促进区域文化产业的发展效率提升具有重要的现实意义。因此,文章基于2011—2018年中国31个省(自治区、直辖市)的面板数据,关注文化产业发展过程中存在产业集聚以及空间、时间上的相关性,构建时空随机前沿模型进行技术效率测算。研究发现:2011—2018年全国文化产业技术效率呈整体下降趋势,空间交互作用及产业集聚对文化产业发展有促进作用,但文化产业表现出明显的惯性,影响了增长动能的传递;融资环境、市场环境、技术环境、制度环境对文化产业技术效率也存在显著影响。     

Did the rising importance of services decelerate overall productivity improvement of Turkey during 2002–2007?

This paper answers the question of what would have been the growth rate of aggregate productivity in Turkey between 2002 and 2007, had it realized China’s rates of productivity growth in agriculture, industry, and services. It does this in a three-sector general equilibrium model calibrated to the Turkish economy over the 2002–2007 period. The main findings are: (i) Turkey would have had much higher aggregate productivity growth over this period if it had experienced China’s service sector productivity growth; (ii) very low productivity growth rates in finance and in the non-market service sector are the main culprits behind Turkey’s weak service-sector performance.     

Corporate Governance and Capital Structure Dynamics

We develop a dynamic tradeoff model to examine the importance of manager–shareholder conflicts in capital structure choice. In the model, firms face taxation, refinancing costs, and liquidation costs. Managers own a fraction of the firms’ equity, capture part of the free cash flow to equity as private benefits, and have control over financing decisions. Using data on leverage choices and the model's predictions for different statistical moments of leverage, we find that agency costs of 1.5% of equity value on average are sufficient to resolve the low‐leverage puzzle and to explain the dynamics of leverage ratios. Our estimates also reveal that agency costs vary significantly across firms and correlate with commonly used proxies for corporate governance.