Uncertainty in climate change impacts on basin-scale freshwater resources – preface to the special issue: the QUEST-GSI methodology and synthesis of results

This paper presents a preface to this Special Issue on the results of the QUEST-GSI (Global Scale Impacts) project on climate change impacts on catchment-scale water resources. A detailed description of the unified methodology, subsequently used in all studies in this issue, is provided. The project method involved running simulations of catchment-scale hydrology using a unified set of past and future climate scenarios, to enable a consistent analysis of the climate impacts around the globe. These scenarios include "policy-relevant" prescribed warming scenarios. This is followed by a synthesis of the key findings. Overall, the studies indicate that in most basins the models project substantial changes to river flow, beyond that observed in the historical record, but that in many cases there is considerable uncertainty in the magnitude and sign of the projected changes. The implications of this for adaptation activities are discussed.

MEASUREMENT AND MODELING OF THE TOXICITY OF BINARY MIXTURES IN THE NEMATODE CAENORHABDITIS ELEGANS-A TEST OF INDEPENDENT ACTION

Ecological risk assessments must increasingly consider the effects of chemical mixtures on the environment as anthropogenic pollution continues to grow in complexity. Yet testing every possible mixture combination is impractical and unfeasible; thus, there is an urgent need for models that can accurately predict mixture toxicity from single-compound data. Currently, two models are frequently used to predict mixture toxicity from single-compound data: Concentration addition and independent action (IA). The accuracy of the predictions generated by these models is currently debated and needs to be resolved before their use in risk assessments can be fully justified. The present study addresses this issue by determining whether the IA model adequately described the toxicity of binary mixtures of five pesticides and other environmental contaminants (cadmium, chlorpyrifos, diuron, nickel, and prochloraz) each with dissimilar modes of action on the reproduction of the nematode Caenorhabditis elegans. In three out of 10 cases, the IA model failed to describe mixture toxicity adequately with significant or antagonism being observed. In a further three cases, there was an indication of synergy, antagonism, and effect-level-dependent deviations, respectively, but these were not statistically significant. The extent of the significant deviations that were found varied, but all were such that the predicted percentage effect seen on reproductive output would have been wrong by 18 to 35% (i.e., the effect concentration expected to cause a 50% effect led to an 85% effect). The presence of such a high number and variety of deviations has important implications for the use of existing mixture toxicity models for risk assessments, especially where all or part of the deviation is synergistic.

Mechanisms and function of flower and inflorescence reversion

Flower and inflorescence reversion involve a switch from floral development back to vegetative development, thus rendering flowering a phase in an ongoing growth pattern rather than a terminal act of the meristem. Although it can be considered an unusual event, reversion raises questions about the nature and function of flowering. It is linked to environmental conditions and is most often a response to conditions opposite to those that induce flowering. Research on molecular genetic mechanisms underlying plant development over the last 15 years has pinpointed some of the key genes involved in the transition to flowering and flower development. Such investigations have also uncovered mutations which reduce floral maintenance or alter the balance between vegetative and floral features of the plant. How this information contributes to an understanding of floral reversion is assessed here. One issue that arises is whether floral commitment (defined as the ability to continue flowering when inductive conditions no longer exist) is a developmental switch affecting the whole plant or is a mechanism which assigns autonomy to individual meristems. A related question is whether floral or vegetative development is the underlying default pathway of the plant. This review begins by considering how studies of flowering in Arabidopsis thaliana have aided understanding of mechanisms of floral maintenance. Arabidopsis has not been found to revert to leaf production in any of the conditions or genetic backgrounds analysed to date. A clear-cut reversion to leaf production has, however, been described in Impatiens balsamina. It is proposed that a single gene controls whether Impatiens reverts or can maintain flowering when inductive conditions are removed, and it is inferred that this gene functions to control the synthesis or transport of a leaf-generated signal. But it is also argued that the susceptibility of Impatiens to reversion is a consequence of the meristem-based mechanisms controlling development of the flower in this species. Thus, in Impatiens, a leaf-derived signal is critical for completion of flowering and can be considered to be the basis of a plant-wide floral commitment that is achieved without accompanying meristem autonomy. The evidence, derived from in vitro and other studies, that similar mechanisms operate in other species is assessed. It is concluded that most species (including Arabidopsis) are less prone to reversion because signals from the leaf are less ephemeral, and the pathways driving flower development have a high level of redundancy that generates meristem autonomy even when leaf-derived signals are weak. This gives stability to the flowering process, even where its initiation is dependent on environmental cues. On this interpretation, Impatiens reversion appears as an anomaly resulting from an unusual combination of leaf signalling and meristem regulation. Nevertheless, it is shown that the ability to revert can serve a function in the life history strategy (perenniality) or reproductive habit (pseudovivipary) of many plants. In these instances reversion has been assimilated into regular plant development and plays a crucial role there.

Exploring costs and benefits of HACCP: a pilot study in the dairy and meat products industry in the European Union

Since 1995 the Directive 93/43/EEC prescribes the application of HACCP principles in food production. However, despite the major importance of food safety, there is a fundamental lack of information on the economic impact of this directive. This project aims to study costs and benefits of HACCP, including the impact of HACCP on public health. Due to the complexity of the issue, we propose to start with a pilot study, limited to dairy and meat products industry in NL, UK and I. Information will be obtained at two levels: production chain and public health. Integration of these results will result in recommendations at the levels of EU member states and industry for regulation and supporting measures, and in recommendations for an effective and efficient approach for a more comprehensive project on costs and benefits of HACCP, covering major parts of the food industry in EU member states.

Computer simulations of structures, energetics and dynamics of myoglobin center dot center dot center dot ligand complexes

Myoglobin has been studied in considerable detail using different experimental and computational techniques over the past decades. Recent developments in time-resolved spectroscopy have provided experimental data amenable to detailed atomistic simulations. The main theme of the present review are results on the structures, energetics and dynamics of ligands ( CO, NO) interacting with myoglobin from computer simulations. Modern computational methods including free energy simulations, mixed quantum mechanics/molecular mechanics simulations, and reactive molecular dynamics simulations provide insight into the dynamics of ligand dynamics in confined spaces complementary to experiment. Application of these methods to calculate and understand experimental observations for myoglobin interacting with CO and NO are presented and discussed.

The UK Department of National Heritage: a model for the development and integration of leisure policy in the new Europe?

Leisure is in the vanguard of a social and cultural revolution which is replacing the former East/West political bipolarity with a globalised economic system in which the new Europe has a central rôle. Within this revolution, leisure, including recreation, culture and tourism, is constructed as the epitome of successful capitalist development; the very legitimisation of the global transmogrification from a production to a consumption orientation. While acting as a direct encouragement to the political transformation in many eastern European states, it is uncertain how the issue of leisure policy is being handled, given its centrality to the new economic order. This paper therefore examines the experience of western Europe, considering in particular the degree to which the newly-created Department of National Heritage in the UK provides a potential model for leisure development and policy integration in the new Europe. Despite an official rhetoric of support and promotion of leisure activities, reflecting the growing economic significance of tourism and the positive relationship between leisure provision and regional economic development, the paper establishes that in the place of the traditional rôle of the state in promoting leisure interests, the introduction of the Department has signified a shift to the use of leisure to promote the Government's interests, particularly in regenerating citizen rights claims towards the market. While an institution such as the Department of National Heritage may have relevance to emerging states as a element in the maintenance of political hegemony, therefore, it is questionable how far it can be viewed as a promoter or protector of leisure as a signifier of a newly-won political, economic and cultural freedom throughout Europe.

Do national cultural differences affect the nature and characteristics of HRM practices? Evidence from Australian and Hong Kong construction firms on remuneration and job autonomy

Human resource management (HRM) plays a pivotal role in attracting and retaining talents. However, there is growing recognition in international HRM literature that the adoption of the widely accepted US/Harvard-inspired HRM model ignores the influences of cultural contexts on HRM practices in different countries. This notion has not been empirically investigated in the construction industry. Based on survey responses from 604 construction professionals from Australia and Hong Kong, this study examines whether: (i) national cultural differences influence individuals’ preference for types of remuneration and job autonomy, (ii) actual organizational HRM practices reflect such preferences and (iii) gaps between individuals’ preferences and actual organizational HRM practices affect job satisfaction. Results showed significant difference in HRM preferences between Australian and Hong Kong respondents and these are reflected in the distinct types of HRM practices adopted by construction firms in the two countries. Findings further indicated that the gap between individuals’ preferences and actual organizational HRM practices is associated with job satisfaction. The results support existing mainstream research and highlight the deficiency of the acultural treatment of HRM that is still apparent in construction management literature. An uncritical literature in the area not only hinders theory development but also potentially undermines the ability of construction firms to attract, recruit, and retain scarce talents.