bluuebunny/crossref_metadata_2025 huggingface dataset:
Dispersed leadership predictor of the work environment for creativity and productivity
Authors: Politis John D.
Published: May 2005

Purpose

This paper examines the relationship between the dimensions of dispersed – self‐management – leadership and a number of work environment dimensions conducive to creativity and productivity.

Design/methodology/approach

The study involves a questionnaire‐based survey of employees from a high technology organisation operating in the United Arab Emirates (UAE). A total of 104 useable questionnaires were received from employees who are engaged in self‐managing activities. These were subjected to a series of correlational and regression analyses.

Findings

There are three major findings in this research. First, the relationship between dispersed leadership and the “stimulant” dimensions of the work environment for creativity is positive and significant. Second, the relationship between dispersed leadership, with the exception of encouraging self‐reinforcement, and the “obstacle” dimensions of the work environment for creativity is negative and significant. Finally, the findings have clearly shown that the “stimulant” dimensions of the work environment for creativity have a positive and significant impact on both creativity and productivity.

Practical implications

The study shows that the role of the leader is to be the provider of a context and situation for creativity and productivity. Thus, the art of leading creative organisations in the UAE is the art of handling people and the task of leadership in such organisations is to provide the people with the work – environmental – conditions under which they can exercise their creativity.

Originality/value

The paper clarifies which of the dispersed leadership behaviours best predict the dimensions of the work environment conducive to creativity and productivity. The paper will assist organisations in the UAE in identifying those particular leader behaviours that appear to have an impact on creativity and productivity.
DiffuNET: The impact of network structure on diffusion of innovation
Authors: Shaw‐Ching Liu Ben , Madhavan Ravindranath , Sudharshan D.
Published: May 2005

Purpose

To provide an explicit model to address the relationships between the structural characteristics of a network and the diffusion of innovations through it. Further, based on the above relationships, this research tries to provide a way to infer diffusion curve parameters (innovation coefficient and imitation coefficient) from network structure (e.g. centralization).

Design/methodology/approach

Based on the network and innovation literatures, we develop a model explicitly relating the structural properties of the network to its innovation and imitation potential, and in turn to the observed diffusion parameters (innovation and imitation coefficients). We first employ current theoretical and empirical results to develop postulates linking six key network properties to innovation and imitation outcomes, and then seek to model their effects in an integrative manner. We argue that the innovation and imitation potentials of a network may be increased by strategically re‐designing the underlying network structure. We validated the model by searching the published empirical literature for available published data on network properties and innovation and imitation coefficients.

Findings

We validated the model by searching the published empirical literature for available published data on network properties and innovation and imitation coefficients. The results reported from various relevant research papers support our model.

Practical implications

This research shows that the innovation and imitation potentials of a network may be increased by strategically re‐designing the underlying network structure; hence, provide guidelines for new product managers to enhance the performance of innovative products by re‐design the underlying network structure.

Originality/value

The model developed in this paper is a breaking through result of synthesizing various traditions of diffusion research, ranging from anthropology and economics to marketing which were developed independently. The research explicitly modeled the diffusion process in terms of the underlying network structure of the relevant population allowing managers and researchers to directly link the diffusion parameters to the structural properties of the network. By doing so, it added value by making it possible to infer diffusion potential from directly measurable network properties. Vis‐à‐vis the network diffusion literature in particular, we added value by “unpacking” the diffusion process into innovation and imitation processes that form the building blocks of contagion. Moreover, we developed a holistic structural model of network diffusion which integrates the several network properties that have hitherto been studied separately.
Configured for innovation: the case of palliative care
Authors: Davison Graydon
Published: May 2005

Purpose

To begin a process of understanding how palliative care organisations are configured to enable innovative multidisciplinary patient care teams and their management in an uncertain, complex and dynamic environment.

Design/methodology/approach

A range of literature was reviewed to suggest configuration and characteristics that were tested using semi‐structured interviews with the senior medical staff member at each of three Australian case study organisations. Data gathered from these interviews was supplemented with data gathered from semi‐structured interviews with multidisciplinary management teams and patient care teams dealing with inpatients and home‐care patients.

Findings

A hybrid configuration is suggested, based on Mintzberg's typology of organisations. Responses from interviews modify some characteristics of the suggested configuration, though generally appearing to support it. Characteristics of the external and internal environments are described.

Research limitations/implications

Palliative care is rarely written off outside the healthcare literature and comparatively infrequently within it. Configuration is used to suggest the characteristics of innovative teams in an uncertain, dynamic, complex environment. The use and management of multidisciplinary patient care teams in palliative care offers interesting insights for a broad range of organisations.

Practical implications

A contribution to the discourse on the relationship between configuration and innovation based in organisations without commercial imperative, delivering multi‐level care for and by people involved in the end‐of‐life process.

Originality/value

The paper continues a line of publications, beginning in 2002, describing the management of innovation in multidisciplinary palliative care teams. The originality and value of this paper and this line of research is in taking a management view of a unique environment that offers insights and lessons to a broad range of organisations.
Real estate portfolio construction and estimation risk
Authors: Lee Stephen , Stevenson Simon
Published: May 2005

Purpose

The use of modern portfolio theory (MPT) in the construction real estate portfolios has two serious limitations when used in anex anteframework: the intertemporal instability of the portfolio weights; and the sharp deterioration in performance of the optimal portfolios outside the sample period used to estimate asset mean returns. Both problems can be traced to wide fluctuations in sample means. Aims to prove that the use of a procedure that ignores the estimation risk due to the uncertain in mean returns is likely to produce sub‐optimal results in subsequent periods.

Design/methodology/approach

This study extends previousex ante‐based studies by evaluatingex postoptimal portfolio allocations in subsequent test periods by using methods that have been proposed to reduce the effect of measurement error on optimal portfolio allocations.

Findings

While techniques designed to handle estimation risk in capital market studies have yielded promising results, they are not completely successful in improving out‐of‐sample performance in this case. It is hypothesised that such results are due to the cyclical nature of property and that the contrarian and mean‐reversion effects picked up in studies of stocks and bonds are not captured when an asset such as direct property is examined. This conclusion is also supported by the strong performance of the tangency portfolios, and in particular the classical unadjusted Sharpe portfolio, over the shorter horizons, which would be consistent with a cyclical momentum effect.

Originality/value

The results suggest that the consideration of the issue of estimation risk is crucial in the use of MPT in developing a successful real estate portfolio strategy.
A critique of stake‐holder theory: management science or a sophisticated ideology of control?
Authors: Antonacopoulou Elena P. , Méric Jérôme
Published: May 2005

In this article a critique of stakeholder theory is presented. The analysis highlights several concerns regarding the scientific rigor of this body of knowledge revealing the assumptions and inconsistencies that underpin its main propositions. The discussion shows in particular some of the internal contradictions between, on the one hand, the ideology of social good, and on the other hand, the ideology of control which we argue is not fully accounted for in the way stakeholder theory was popularized in recent years. Our critique opens up more possibilities for engaging with stakeholder theory acknowledging the underlying values that are at stake, thus, revealing the political and value‐laden nature of the concept of stake‐holder. What we seek to draw particular attention to is the way stake‐holder analysis reveals the challenges when not only subjectivities but identities are at stake. This latter point we hope will encourage greater reflexivity among theorists and researchers in this field, recognizing that their personal biases and partialities influence their scholarship, and the way they shape the ideologies stakeholder theory is presented by.
Stakeholder theory, society and social cohesion
Authors: Lépineux François
Published: May 2005

Stakeholder theory is a “weak” theory, which suffers from a number of flaws. This article is based on the intuition that many of these problems are linked together, and that they are fundamentally due to the fact that stakeholder theory fails to appreciate the place of civil society as a stakeholder. It starts with an examination of the confusing status of society in stakeholder theory, and suggests that civil society should be on top of the stakeholder list. It then underlines the emergence of a global society, distinct from national societies. An extended classification system is presented, which comprises a binary categorization, an intermediate taxonomy, and a developed typology; this system is illustrated in the form of a mapping. The article then addresses the issue of the theory’s normative underpinnings: the concept of social cohesion is proposed as an alternative justification. The meaning of this concept is specified, and its relevance as a normative foundation is justified. Eventually, this reinterpretation of stakeholder theory, which emphasizes the importance of civil society and social cohesion, provides some rationales for the connection of its empirical and normative streams – thus rendering it more consistent and more robust.
Changing managers’ values towards a broader stakeholder orientation
Authors: Sachs Sybille , Rühli Edwin
Published: May 2005

Challenged by recent incidents as they occurred at Enron, WorldCom, Disney and Xerox, management has to rethink its values and to consider the expectations of their stakeholders. In reality, it can be observed that some firms are already on a learning path to adopt a broader stakeholder‐oriented view than before. In order to implement the stakeholder view better into strategic thinking of management, top managers have to change their values which are challenged by stakeholder‐oriented incentives. Based on three comparative case studies some first propositions are developed.
Towards a stakeholder responsible approach: the constructive role of reporting
Authors: Zambon Stefano , Del Bello Adele
Published: May 2005

It is commonly recognized that nowadays social and environmental aspects, and more in general stakeholder‐linked issues, are becoming important corporate value drivers. It is also rather clear that there is a strong relationship between the stakeholder perspective, and a number of concepts and practices which stress non‐financial aspects of company behavior, such as corporate social responsibility (CSR), sustainability (including environmental respect) and corporate governance. Accordingly, these emerging company ideas and attitudes are here collectively referred to as “stakeholder responsible (or oriented) approaches”. Current literature underlines especially the importance and difficulty of the implementation phase of these approaches into concrete company actions, but it seems to largely overlook the impact which the reporting process has on both concepts and company actions. On the basis of an ad hoc theoretical model, the paper aims to provide insights into the “active role” subtly played by stakeholder oriented reporting (e.g. social and sustainability statements) in constructing and reconstructing the underlying ideas and notions, as well as company behaviors in this field. Far from being a neutral and “passive” mirror of the stakeholder responsible approach implemented, reporting carries out the decisive and constitutive role to concretize abstract concepts, and to visualize company activities, thus substantially contributing to make the “stakeholder philosophy” viable and reliable.
The measurement of responsible governance and management of NPOs in New Zealand: an evaluation tool for NPOs, donors and government. “If you have no money – you have no mission”
Authors: Mueller J. , Williams D. , Higgins A. , Tou M.
Published: May 2005

In New Zealand, as in many other developed countries around the world, news is made not just by those many organizations with superb performance records, but also by the few whose achievements fall far short of donor expectations and public perceptions. One of the core competencies of NPOs should be the ability to build strong donor relationships (Lewis, 1998), to create a sustainable income model which allows the organization to focus on their operational efforts. Funding uncertainties affect the ability to operate, to motivate and to plan for the future. Research (Mueller et al., 2004) was undertaken to determine how the relationship between NPOs and donors can be improved. This work focused on the identification of areas where NPOs need support to improve their governance and management functions. Both donors and NPOs were investigated, and the results were used to speculate in which areas external support would be most helpful and where donor/NPO perceptions differ. NPOs and donors indicated that they are aware that NPOs require both governance and managerial support. Both the NPOs and the donors indicated that an objective evaluation system would be valuable to them as evidence of credibility. Such a system would also help to guide the internal assessment process. These findings led to the development of the Looking Glass Evaluation Tool (LGET) which measures an organization along the following dimensions: effective management, strategic planning, advocacy, legal framework, governance and fundraising. The dimensions were derived partly from the work of Lester Salamon from the Nathan Cummings Foundation, New York. The LGET questions an organization about its levels of understanding, planning and implementation of governance and managerial functions and provides a snapshot of the organization’s structural effectiveness. The tool does not test the outcomes of the organization’s work; but speculates that an organization with poor internal structure will be less likely to perform sustainably, especially in the area of creating strong donor relationships. The tool is completed through a guided self‐assessment process, which is then reviewed with the organization to assure a clear understanding of the review objectives. From this snapshot of performance in a wide range of areas, organizations can focus resources on specific parts of their work for improvement. The LGET has been trialled in its prototype form in a number of NPOs in New Zealand, including a Maori charitable trust and has been favorably received.
Managing product variety in quotation processes
Authors: Bramham Jo , MacCarthy Bart , Guinery Jane
Published: May 2005

Purpose

Manufacturers across many sectors increasingly operate in high variety environments. Research evidence suggests that variety has a negative impact on performance. However, the research literature is limited on the enablers that allow variety to be managed effectively and efficiently at the “front‐end” of an organisation and in quotation processes in particular.

Design/methodology/approach

This paper presents case analysis of the quotation processes from manufacturers operating in high‐variety environments. Qualitative process modelling tools have been developed to allow representation of process complexities and informal process elements.

Findings

Findings are presented on generic mechanisms for absorbing and mitigating the impact of variety on quotation processes. A generic quotation process model is presented comprising four key decisions centres: customization request initiation and information gathering on customer needs, classification of requests, resource control, and identification of information for reuse.

Practical implications

The implications of the study for the automation of quotation processes in high variety and mass customization environments are discussed and it is speculated that different decision centres will dominate in different environments.

Originality/value

The generic model developed by this research offers insight into the functioning of the core process elements of the quotation system. Reviewing an organisation's structure and the information systems infrastructure supporting these decision centres should lead to the identification of potential system or reorganisation improvements.
A case study of product modularization on supply chain design and coordination in Hong Kong and China
Authors: Lau A.K.W. , Yam R.C.M.
Published: May 2005

Purpose

Modular product design is a practice manufacturers frequently adopt to develop new products. Some literature has reported the importance of the modular product design and its effect on supply chain management. However, until now, very few empirical researches have examined the relationship of product modularisation and supply chain design and coordination. Furthermore, the exploration on how manufacturers capitalize upon product modularization with supply chain design and coordination is rarely reported. This paper addresses this gap.

Design/methodology/approach

This paper conducted a case study to review the experience of an Audio Consumer Electronics Manufacturer (ACEM) in Hong Kong and China. This company has successfully integrated modular product design with supply chain design and coordination for more than five years.

Findings

Results indicate that product modularization affects supply chain design, whereas product innovation influences on supply chain coordination.

Originality/value

This study explores new relationships between supply chain and modular product design into three propositions for further studies. The first proposition shows that supply chain for modular product design has one more level than integrated product design in multiple‐tier supply chain. The second proposition shows that, regardless of either a modular or integrated product, an innovative product requires closer supply chain coordination than a conventional product in new product development. The final proposition shows that product modularization with close supply chain design and coordination brings down the inventory level, improve the quality of conformance and reduce development lead time.
Multi‐attribute information technology project selection using fuzzy axiomatic design
Authors: Kulak Osman , Kahraman Cengiz , Öztayşi Başar , Tanyaş Mehmet
Published: May 2005

Purpose

Significant productivity improvements have been experienced in business by information technology (IT) implementations in latest decades. However, IT project selection is an important problem because a significant part of IT expenditure is wasted and almost half of IT projects realize no net benefits. Since axiomatic design (AD) has the characteristics of multi‐attribute evaluation, it is proposed for multi‐attribute comparison of information technology systems (ITS).

Design/methodology/approach

The comparison of ITS is made for the cases of both complete and incomplete information. The crisp AD approach for complete information and the fuzzy AD approach for incomplete information are developed. The numerical applications of both crisp and fuzzy AD approaches in the comparison of ITS are also given.

Findings

The AD approach takes into account the design range of each criterion, determined by the designer. Thus, the alternative providing the design ranges is selected in AD approach while the alternative meeting the criteria at their best levels is selected in many other methods. This opportunity is not possible when many other existing methods such as AHP, fuzzy AHP, and scoring models are used. The AD approach also differs from many other existing methods from the point of the rejection of an alternative when it does not meet the design range of any criterion.

Research limitations/implications

For future research, it is suggested that researchers study weighted crisp and fuzzy AD approaches.

Originality/value

This paper is the first which develops the fuzzy AD approach and uses it in the comparison of ITS.
A study of enterprise human resource competence appraisement
Authors: Liu Xiaohong , Ruan Da , Xu Yang
Published: May 2005

Purpose

For an enterprise, the competence of human resource is more important than the intellect or the basic quality of human resource. This paper aims to present a competence appraisement model of human resource in an enterprise.

Design/methodology/approach

The paper puts forward the appraisement index architecture of enterprise human resource competence on the foundation of adopting the concept and models of competence, and establishes a general model of the enterprise human resource competence appraisement.

Findings

The results obtained in this paper provide a foundation to establish a relatively reasonable and efficient enterprise appraisement system of human resources.

Originality/value

The research offers information about the enterprise appraisement information processing system of human resources.
Outsourcing logistics activities in Turkey
Authors: Aktas E. , Ulengin F.
Published: May 2005

Purpose

This research aims to determine the current situation of outsourcing logistics activities in Turkey, a country which has a great potential for logistics activities among the surrounding continents because of its geographical location.

Design/methodology/approach

Survey analysis was conducted with 250 of the top 500 Turkish firms specified by the Istanbul Chamber of Commerce for the year 2001. These firms are selected based on the firms' total sales volume, profitability, and other financial performance indicators. The responses were evaluated statistically using SPSS software. Factor and cluster analyses were utilized to determine the behavior of respondents against their logistics service providers and to categorize the respondents.

Findings

The focus of the part of the survey is basically in the following areas: logistics functions outsourced by Turkish firms; the extent to which logistics functions in general and transportation functions in particular are outsourced by Turkish firms; and the criteria used to select and evaluate the performance of the outsourcing firms. The performance of the first three outsourcing firms currently used by Turkish firms.

Originality/value

This study shows that the power of third party logistics (3PL) firms in Turkey is underestimated. The firms that outsource their logistics activities in Turkey are 95 percent foreign capitalized. Turkish businessmen think that they should do their business themselves and they are not aware of the benefits of outsourcing logistics activities. In fact, in selecting the transportation carrier, they consider different criteria but the general tendency is either to select the carrier that has a good reputation and/or the one which is easy to collaborate with.
Addressing uncertainty and inequality in nuclear policy
Authors: Laes E. , D'haeseleer W. , Weiler R.
Published: May 2005

Purpose

This paper analyses the justification of technological choices and options in the context of nuclear energy policy. We argue that “society” increasingly demands a justification with regard to the level of uncertainty and inequality a certain technological choice induces. We aim to demonstrate that policy makers in fact do address these issues, but depending on how they define the problem, this is done in a more explicit (overt) or implicit (covert) way.

Design/methodology/approach

First, the changing context with regard to the justification of technological choices is briefly sketched. We draw the attention to the link between the way a certain (energy) policy problem is defined, and the way the framework for political decision‐making is set up in response to the problem. In order to clarify this observation, we make use of a scheme derived from policy sciences, mapping out policy problems in two dimensions: the (lack of) certainty concerning the kinds of knowledge a problem may require, and the (lack of) consensus on relevant values (i.e. “the common good”, “basic rights”, etc.). Each type of policy problem requires a distinct solution strategy. A so‐called Type III‐error occurs when the wrong problem is solved by employing a strategy which does not apply to the problem at hand. In that case, political theory predicts strategic behavior in order to actively suppress or blur value differences. The Belgian decision to phase out nuclear power is used as a case study to illustrate some of the theoretical implications of the scheme.

Findings

Several Type III‐errors could be demonstrated in the case of the Belgian phase out. In this case, social learning was severely hampered by different methodological approaches; lack of data; different perceptions of relevant time scales; different framing of the problem; institutional barriers; lack of communication; strategic use of scientific assessments by different stakeholders; and insufficient knowledge of scientific assessments.

Originality/value

The paper aims to broaden the debate on energy policy outside the boundaries of institutional decision‐making. We conclude with some practical recommendations for future energy policy, regarding problem structuring, defining possible options, goal and strategy formulation and monitoring of choices.
“What Are You Going to Do with the Village's Knowledge?” Talking Tradition, Talking Law in Hopi Tribal Court
Authors: Richland Justin B.
Published: May 2005

Though the details of face-to-face talk and interaction have been studied in Anglo American and British courtrooms, few attempts have been made to extend similar analyses to the study of contemporary indigenous and (post)colonial legal institutions that continue to employ legal processes informed by both Anglo-style adversarial notions of law and “local” notions of law, culture, and tradition. Using methods of legal discourse analysis and language ideology studies, this article investigates how interlocutors in a hearing before the courts of the Hopi Indian Nation construct discourses of tradition and Anglo American jurisprudence in multiple and competing ways, and for significant sociopolitical effect. An argument is thus made for attending to the microdetails of sociolegal interactions as an important site for exploring the complex articulations between the contemporary lives of indigenous peoples and the laws with which they are imbricated.
The Vanishing Victim: Criminal Law and Gender in Jordan
Authors: Warrick Catherine
Published: May 2005

Focusing on the issues of rape and honor killings in the Arab world, particularly Jordan, this article investigates the use of criminal laws as an element in political legitimation. These laws are an arena for contestation not merely over policy choices, but over the nature of the sociopolitical order as well. Recent debates over the alteration or preservation of such laws have highlighted the use of legal codes as an expression of dominant values in a political system. I argue that the use of gendered legal systems to serve legitimation claims has important implications for the prospects of democratization.
Passing and Strategic Voting on the U.S. Supreme Court
Authors: Johnson Timothy R. , Spriggs James F. , Wahlbeck Paul J.
Published: May 2005

Analyzing strategic aspects of judicial decisionmaking is an important element in understanding how law develops. In this article, we examine sophisticated voting on the U.S. Supreme Court by empirically modeling justices' decisions to pass when it is their turn to vote during conference discussions. We argue that, due to the opinion assignment norm, the chief justice may pass when one of the key conditions necessary for sophisticated voting—certainty about the views held by other justices and the agenda—is lacking. By passing, the chief can view his colleagues' votes in order to determine which vote will allow him to assign the majority opinion and, ultimately, forward his policy preferences. Using data from Justice Lewis F. Powell's conference notes, we show that the chief passes for this purpose, and that doing so is an effective strategy. In addition, we show that the senior associate justice in a case, who has a nontrivial chance of assigning the majority opinion, also passes for strategic reasons. As we expect, the data indicate that the remaining associates seem not to pass for strategic purposes.
The importance of population origin and environment on clonal and sexual reproduction in the alpine plant Geum reptans
Authors: PLUESS A. R. , STÖCKLIN J.
Published: May 2005

Reproductive behaviour of plants may change in contrasting habitats. In two separate glasshouse experiments, we studied effects of population origin (early vs. late successional and low vs. high altitudinal habitats) and environmental effects (competition and temperature) on plant size and sexual vs. clonal reproduction in Geum reptans L.

Plant size and reproduction differed significantly among populations, but only plant size differed between contrasting habitats.

If plants grew with competition or at warm temperature, plant size and reproduction were reduced and more plants reproduced only with stolons. Individuals with flowers were larger than those that reproduced only with stolons, indicating a smaller minimum plant size for clonal than for sexual reproduction.

Populations of different origin changed little in their response to environmental treatments. Plants from early successional habitats tended to produce more flowers in the competition‐free treatment, whereas in plants from late successional habitats the opposite was true.

The results indicate limited adaptation in reproductive behaviour to contrasting habitats. Nevertheless, great size‐dependent plasticity in the proportion of sexual vs. clonal reproduction ensures population persistence and reproduction in a large range of habitat conditions.
Effect Of Height On Tree Hydraulic Conductance Incompletely Compensated By Xylem Tapering
Authors: ZAEHLE S.
Published: May 2005

The hydraulic limitation theory proposes that the decline of forest productivity with age is a consequence of the loss of whole‐plant and leaf‐specific hydraulic conductance with tree height caused by increased friction. Recent theoretical analyses have suggested that tapering (the broadening of xylem vessel diameter from terminal branches to the base of the stem) could compensate completely for the effect of tree height on hydraulic conductance, and thus on tree growth.

The data available for testing this hypothesis are limited, but they do not support the implication that whole‐tree and leaf‐specific hydraulic conductance are generally independent of tree height. Tapering cannot exclude hydraulic limitation as the principle mechanism for the observed decline in growth.

Reduction of the leaf‐to‐sapwood area ratio, decreased leaf water potential, loss of leaf‐cell turgor, or osmotic adjustments in taller trees could reduce the effect of increased plant hydraulic resistance on stomatal conductance with height. However, these mechanisms operate with diminishing returns, as they infer increased costs to the tree that will ultimately limit tree growth. To understand the decline in forest growth, the effects of these acclimation mechanisms on carbon uptake and allocation should be considered.
Ecological correlates of seed survival after ingestion by Fallow Deer
Authors: MOUISSIE A. MAARTEN , VAN DER VEEN CARMEN E. J. , VEEN G. F. (CISKA) , VAN DIGGELEN RUDY
Published: May 2005

The survival and retention of seeds was studied by feeding known quantities of seeds of 25 species to four captive Fallow Deer (Dama dama L.). To test for ecological correlates, plant species were selected to represent large variation in seed size, seed shape, seed longevity and habitat fertility.

Seeds of 24 out of 25 fed plant species survived ingestion and defecation by Fallow Deer. Seed survival ranged between 0·5 and 42% of germinable seeds fed. Time to recover 50% of all seeds defecated by Fallow Deer in faeces averaged 25 h, and ranged from 13 to 38 h.

Seed survival was negatively related to seed mass (R = 0·65) and variance of unit seed dimensions (R = −0·56), and positively related to seed longevity (R = 0·40), but not related to habitat fertility. Log10 of (seed mass × variance of seed dimensions) was the best predictor of seed survival (R = −0·68).

The ecological correlates of seed survival presented here can help us to estimate the ability of plant species to disperse seeds over long distances.
How should toxic secondary metabolites be distributed between the leaves of a fast‐growing plant to minimize the impact of herbivory?
Authors: LAMBDON P. W. , HASSALL M.
Published: May 2005

This paper considers the possibility that the key determinant of leaf age feeding preferences in foliovores is not the concentration of either nutrients or secondary metabolites, but is the ratio of the two.

In some fast‐growing plants, nitrogen is most heavily defended by defensive toxins in the young leaves. This empowers the use of a simple model of leaf‐age preference, based on the conflict between maximizing nutrient intake and minimizing toxicosis.

Young leaves are particularly valuable, not only because they lock up nitrogen, but also because their assimilative value is high. We calculate the loss of value due to herbivory and find that, if the herbivore is moderately intolerant of toxicity and feeds selectively on its predicted optimal leaf age, the costs of damage are greatly reduced. However, efficient toxin distribution protects the plant only if it grows rapidly, so that the well protected young foliage retains a high value.

The trends are reconcilable with observed leaf‐age preferences of both polyphagous and oligophagous species. There is, as yet, little empirical evidence to substantiate the model, but it may be useful for future studies to focus on the toxin : nutrient ratio as a potentially important determinant of feeding preferences.
Nutrient resorption of wetland graminoids is related to the type of nutrient limitation
Authors: GÜSEWELL S.
Published: May 2005

Nitrogen or phosphorus limits plant growth in many wetlands. If specific mechanisms reducing losses of the growth‐limiting nutrient have been favoured by selection, the N and P resorption efficiency (RE) during leaf senescence (NRE, PRE: the fraction of N or P resorbed) might depend on the type of nutrient limitation.

The size, mass, and N and P concentrations of green and senesced leaves were determined for 10 graminoid species at Dutch and Swiss wetland sites, with N : P ratios in leaves (6–27 by mass) indicating N or P limitation.

During senescence, leaf area decreased by 8–19%, and leaf mass by 8–38%; NRE ranged from 0 to 87%, and PRE from 30 to 96%. PRE correlated strongly with NRE (r = 0·91) but was, on average, 17% higher. Within the Swiss or Dutch sites, NRE and PRE did not correlate with foliar N : P ratios, indicating that RE was not directly adjusted to the type of nutrient limitation.

NRE and PRE were, on average, higher at the P‐limited Swiss sites than at the N‐limited Dutch sites. Because PRE exceeded NRE, high RE would be most beneficial when P limits plant growth. This may have contributed to the dominance of graminoids with high RE in P‐limited wetlands.
Metals and amyloid‐β in Alzheimer's disease
Authors: Maynard Christa J. , Bush Ashley I. , Masters Colin L. , Cappai Roberto , Li Qiao‐Xin
Published: May 2005

Mounting evidence is demonstrating roles for the amyloid precursor protein (APP) and its proteolytic product Aβ in metal homeostasis. Furthermore, aberrant metal homeostasis is observed in patients with Alzheimer's disease (AD), and this may contribute to AD pathogenesis, by enhancing the formation of reactive oxygen species and toxic Aβ oligomers and facilitating the formation of the hallmark amyloid deposits in AD brain. Indeed, zinc released from synaptic activity has been shown to induce parenchymal and cerebrovascular amyloid in transgenic mice. On the other hand, abnormal metabolism of APP and Aβ may impair brain metal homeostasis as part of the AD pathogenic process. Aβ and APP expression have both been shown to decrease brain copper (Cu) levels, whereas increasing brain Cu availability results in decreased levels of Aβ and amyloid plaque formation in transgenic mice. Lowering Cu concentrations can downregulate the transcription of APP, strengthening the hypothesis that APP and Aβ form part of the Cu homeostatic machinery in the brain. This is a complex pathway, and it appears that when the sensitive metal balance in the brain is sufficiently disrupted, it can lead to the self‐perpetuating pathogenesis of AD. Clinical trials are currently studying agents that can remedy abnormal Aβ–metal interactions.
Concepts for the treatment of Alzheimer's disease: molecular mechanisms and clinical application
Authors: Pietrzik Claus , Behl Christian
Published: May 2005

To date, various strategies have been developed in order to prevent or to slow down the progression of Alzheimer's disease (AD). Despite the medical need for an effective therapeutic treatment of AD, progress towards this goal is painstakingly slow. Although AD is the most common neurodegenerative disorder and a large amount of primary basic and clinical research has been performed already, it appears very difficult to identify appropriate targets, which would promise fast, effective and safe strategies to combat the disease onset and progression. In this review, we present some of clinically applied treatment options, which may improve AD symptoms for a short period but so far lack the ability to prevent or halt this devastating disease. Additionally, we summarize some of the experimental approaches in AD therapy, which might lead to the development of more promising drugs in the future.
Adaptation to thermal stress in lichen‐eating webspinners (Embioptera): habitat choice, domicile construction and the potential role of heat shock proteins
Authors: EDGERLY J. S. , TADIMALLA A. , DAHLHOFF E. P.
Published: May 2005

Embiids are a unique group of web‐spinning insects, which construct silk domiciles. In sunny habitats, silk may provide a shady refuge, or exacerbate exposure to high temperatures. Here we present the first description of the thermal biology of embiids, focusing on Notoligotoma hardyi from Magnetic Island, Australia.

We recorded natural colony positions and temperature of silk domiciles relative to incident radiation, and manipulated locations of domiciles on sunny (north‐facing) and shady (south‐facing) rock faces to test whether silk dampens thermal exposure. We also compared responses to laboratory heat stress in N. hardyi with two other embiids: Australembia incompta (Magnetic Island) and Antipaluria urichi (rainforest).

Temperatures of air (TA), rocks (TR) and domiciles (TD) are significantly hotter for north‐ than south‐facing colonies. North‐facing colonies have less extensive silk coverings and are found in crevices. For natural and experimentally manipulated north‐facing colonies, TD was cooler than TR but hotter than TA, whereas TD and TA were similar for south‐facing colonies. Individuals living in north‐facing colonies adjusted position to remain in the shade. Ability to recover from heat exposure was greatest in Australian embiids and was linked to expression of heat shock proteins.

In sunny microhabitats, silk reduces but does not prevent exposure to physiologically stressful temperatures. N. hardyi tolerates thermal extremes using a combination of behavioural thermal regulation, microhabitat selection and a robust heat shock response.
Predator‐specific changes in the morphology and swimming performance of larval Rana lessonae
Authors: WILSON R. S. , KRAFT P. G. , VAN DAMME R.
Published: May 2005

We investigated the morphological responses of larval Rana lessonae to the presence of two predators with substantially different prey‐detection and capture techniques; larval dragonflies (Aeshna cyanea) and the Pumpkinseed Sunfish (Lepomis gibossus).

We also examined the functional implications of any predator‐induced morphological variation on their swimming ability by assessing performance during the initial stages of a startle response.

We found the morphological responses of larval R. lessonae were dependent on the specific predator present. Tadpoles raised in the presence of dragonfly larvae preying upon conspecific tadpoles developed total tail heights 5·4% deeper and tail muscles 4·7% shallower than tadpoles raised in a non‐predator environment, while tadpoles raised with sunfish possessed tails 2% shallower and tail muscles 2·5% higher than non‐predator‐exposed tadpoles.

Predator‐induced morphological variation also significantly influenced swimming performance. Tadpoles raised with sunfish possessed swimming speeds 9·5 and 14·6% higher than non‐ and dragonfly predator groups, respectively.

Thus, the expression of these alternative predator‐morphs leads to a functional trade‐off in performance between the different environments.
Relative importance of plastic vs genetic factors in adaptive differentiation: geographical variation for stress resistance in Drosophila melanogaster from eastern Australia
Authors: HOFFMANN A. A. , SHIRRIFFS J. , SCOTT M.
Published: May 2005

Heritable clinal patterns for stress resistance traits have been described in a number of invertebrate species but patterns are usually characterized on populations reared under constant conditions. Here we examined the impact of simulated seasonal variation in temperature/photoperiod as well as constant conditions on stress resistance in eight Drosophila melanogaster populations from eastern Australia across a latitude range of 27 degrees.

Desiccation resistance was relatively higher under summer compared with winter/constant conditions, but this trait and starvation resistance did not exhibit clinal variation. Winter conditions increased cold resistance as measured by chill coma recovery time, and decreased heat resistance as measured by time to knock down in a vial.

Clinal patterns were evident for the thermal resistance traits regardless of conditions, and involved increased heat resistance and decreased cold resistance in tropical populations. Latitudinal patterns were steeper for cold resistance than for heat resistance.

To compare the relative impact of plastic vs genetic changes along the cline, differences in trait means were expressed relative to differences between populations from cline ends. For cold and heat resistance, differences between environmental conditions were approximately 1·5× greater than the heritable differences.
The effect of slug grazing on vegetation development and plant species diversity in an experimental grassland
Authors: BUSCHMANN H. , KELLER M. , PORRET N. , DIETZ H. , EDWARDS P. J.
Published: May 2005

Generalist herbivores such as slugs have the potential not only to reduce plant density and biomass, but also to alter species diversity within vegetation. Their impact on species diversity may be either negative, if they concentrate feeding on less abundant plant species, or positive, if they feed on the most abundant species.

This study investigated the influence of slugs on plant species diversity in experimental swards produced by sowing aLolium perenne/Trifolium repensseed mixture in field plots with a large seed bank of mainly arable species. Half of the plots were grazed byArion lusitanicusMabille. Plant cover, above‐ground biomass and number of plant species were measured over a 3‐year period.

Vegetation cover increased in the control plots from 50% in the first year to 90% in the third year. Cover was significantly lower in the slug plots in the first year (>22%), while there were only small differences between treatments in the third year. Slugs reduced total above‐ground biomass by >25% in both the first and third years.

Slugs had a negative impact on plant species diversity in the first year, particularly by reducing forb species. In contrast, plant species diversity after 3 years was higher in the slug plots than in the controls, because of the higher number of forb species. Under slug grazing, the biomass and cover of annual and palatable species were reduced, but not the numbers of these species.

Our results suggest that slugs can have a significant effect on plant species diversity in plant communities, but that the direction of the effect changes during the course of succession. In the earliest stages, when most species are present as seedlings or juveniles, slug grazing leads to reduced species diversity because favoured species are eliminated. In closed vegetation, in which competitive interactions are important, slugs may reduce the dominance of the more competitive species and thus provide gaps in which plants can establish from seed. As a consequence, slugs tend to cause an increase in plant species diversity, and may also reduce the rate of successional change by promoting the persistence of annual species.