Metabolic costs of terpenoid accumulation in higher plants

The net value of any plant trait can be assessed by measuring the costs and benefits associated with that trait. While the other contributors to this issue examine the possible benefits of terpenoids to plants, this article explores the metabolic costs of terpenoid accumulation in plants in the light of recent advances in terpenoid biochemistry. Terpenoids are more expensive to manufacture per gram than most other primary and secondary metabolites due to their extensive chemical reduction. The enzyme costs of making terpenoids are also high since terpenoid biosynthetic enzymes are apparently not shared with other metabolic pathways. In fact, plant cells may even possess more than one set of enzymes for catalyzing the basic steps of terpenoid formation. Terpenoids are usually sequestered in complex, multicellular secretory structures, and so storage costs for these substances are also likely to be substantial. However, not all of the processes involved in terpenoid accumulation require large investments of resources. For instance, the maintenance of terpenoid pools is probably inexpensive because there is no evidence that substantial quantities of terpenes are lost as a result of metabolic turnover, volatilization, or leaching. Moreover, plants may reduce their net terpenoid costs by employing individual compounds in more than one role or by catabolizing substances that are no longer needed, although it is still unclear if such practices are widespread. These findings (and other facets of terpenoid biochemistry and physiology) are discussed in relation to the assumptions and predictions of several current theories of plant defense, including the carbonnutrient balance hypothesis, the growth-differentiation balance hypothesis, and the resource availability hypothesis.     

采矿权与其它无形资产的比较分析

采矿权是一种无形资产，它具有无形资产的共性，不具有实物形态，属于非货币性长期资产，是为企业使用而非出售的资产，在创造经济利益方面存在较大不确定性；也有与其它无形资产不同的特点，如采矿权主体资格的特定性、采矿权的流转性、采矿权的有偿性、采矿权的排他性、采矿权的逐渐消失性、采矿权的非智力性和非经营性。     

天然气储量价值评估模型

储量的资产评估和价值评价是矿业权流转、合作开发、上市评估及企业内部管理的必要步骤和前提。本文在成本法计算储量价值的基础上,首次提出了天然气的储量价值评估模型(超额收益综合模型)。模型以获得油气储量所需花费的社会平均勘探成本作为确定储量的基本价格,在社会平均勘探成本的基础上附加一定的平均利润和由于开采条件不同造成的级差价格,以此作为油气储量的价格。本文建立的天然气储量价值评估模型,在长庆油田和川西气田得到了实际的应用,初步印证了模型的先进性、实用性。     

Intangible Asset Dynamics and Firm Behaviour

We study the adoption of different patterns of intangible asset (IA) accumulation in manufacturing firms. Contrary to most of the previous literature, we find such patterns to be highly differentiated. In particular, we identify three types of firm behaviour: high and persistent, low and persistent, and discontinuous. We link the capability-based view of the firm to theories of asset complementarities and market signalling to explain how firm-specific traits affect such behaviours. We obtain the following results: first, the persistent accumulation of IAs is favoured by the internal availability of highly skilled personnel; second, firms with (a) large IA base and (b) high propensity to exploit complementarities in the asset stocks are more likely to persistently accumulate IAs than to discontinuously or never accumulate IAs and third, the adoption of quality management standards facilitates the accumulation of IAs, especially if this is done discontinuously. This paper adds to the previous literature in two ways: first, it highlights the existence of great heterogeneity in the dynamics of IA accumulation and, second, it provides an explanation for such heterogeneity.     

大型酒店能源消耗合理性评价及预算控制

以实例举出国内有代表性的大型综合性酒店近三年的能源消耗和营业额现状；用总能源费／总营业额的当量比值I修作为能源消耗合理程度的评价指标统分出能耗标准对应I修值的范围；指出目前能源预算控制存在的问题和正确的能源预算方法，实际应用效果显著。     

人-岗匹配与工作态度:自我效能感的中介作用

目的在于揭示人-岗匹配对员工工作态度的影响作用.首先,基于需要-满足理论,论证了人-岗匹配对员工工作态度(工作满意度、组织承诺和离职意愿)的直接影响;接着,结合社会认知理论,进一步提出员工的自我效能感在人-岗匹配和员工工作态度之间起到部分中介作用.研究从深圳市16家房地产企业收集了244份问卷,实证检验结果验证了所提出...     

Water industry asset management in England and Wales: successes and challenges

This paper considers the structure, regulation and performance of the water industry in England and Wales in the postprivatisation period from 1989. The paper examines the improvements achieved in drinking water and wastewater effluent quality and in the overall performance. The challenges facing the industry in the areas of water resource planning, energy efficiency and chemical consumption, arising from climate change, are also considered. The paper considers how the industry's current approach and attitude towards research and development (R&D) will influence its ability to meet the latest challenges laid down by the regulators. The paper calls for increased emphasis on, and incentive for, R&D in the water industry to ensure sustainable solutions in both water and sewage treatment.     

无形资产管理系统的设计与实现

无形资产是指企业拥有或者控制的没有实物形态的可辨认非货币性资产。结合当代计算机技术的发展和计算机数据库的广泛应用,完全可以设计一款软件使得对无形资产合理的管理、使用更方便、更科学、更合理,最大限度地发挥无形资产带来的效益。本设计采用基于B/S架构的WEB程序,只需要在服务器上安装部署一次,所有连接网络的电脑都可以访问。结构简洁,脉络清晰,管理操作简单快捷。     

把移民安置工作做得更好

建国以来，水库移民1000余万人，对我国水利水电建设作出了积极贡献，但也存在一些需要研究解决的问题，为此，对当前水利水电工程移民安置出现的一些问题，从设计，管理，移民工程招投标，监理，验收等方面进行了揭示和论述。认为，今后一是要严格按照规范要求，努力提高移民安置规划设计质量，增强规划设计可操作性，二是要加强移民安置实施管理，提高移民安置实施质量，减少失误。     

A longitudinal study of the moderating role of extraversion: Leader-member exchange, performance, and turnover during new executive development.

Identifying factors that help or hinder new executives in "getting up to speed" quickly and remaining with an organization is vital to maximizing the effectiveness of executive development. The current study extends past research by examining extraversion as a moderator of relationships between leader-member exchange (LMX) and performance, turnover intentions, and actual turnover for an executive sample. The sample consisted of 116 new executives who were surveyed prior to starting their employment and at 3 months postentry. A total of 67 senior executives rated these new executives in terms of overall performance at 6 months postentry. Turnover data were gathered from company records 3 1/2 years later. Hierarchical regression results showed that LMX was not related to performance or turnover intentions for those high in extraversion; but for individuals low in extraversion, there was a relation between LMX, performance, and turnover intentions. Furthermore, survival analyses showed that LMX was only related to turnover-hazard rate for individuals low in extraversion. (PsycINFO Database Record (c) 2011 APA, all rights reserved)