Diurnal changes in the photochemical efficiency of the symbiotic dinoflagellates (Dinophyceae) of corals: photoprotection, photoinactivation and the relationship to coral bleaching

The photochemical efficiency of symbiotic dinoflagellates within the tissues of two reef-building corals in response to normal and excess irradiance at wafer temperatures < 30 C were investigated using pulse amplitude modulated (PAM) chlorophyll fluorescence techniques, Dark-adapted F-v/F-m showed clear diurnal changes, decreasing to a low at solar noon and increasing in the afternoon. However, F-v/F-m also drifted downwards at night or in prolonged darkness, and increased rapidly during the early morning twilight. This parameter also increased when the oxygen concentration of the wafer holding the corals was increased. Such changes have not been described previously, and most probably reflect state transition's associated with PQ pool reduction via chlororespiration. These unusual characteristics may be a feature of an endosymbiotic environment, reflective of the well-documented night-time tissue hypoxia that occurs in corals. F-v/F-m decreased to 0.25 in response to full sunlight in shade-acclimated (shade) colonies of Stylophora pistillata, which is considerably lower than in light-acclimated (sun) colonies. In sun colonies, the reversible decrease in F-v/F-m was caused by a lowering of F-m and F-o suggesting photoprotection and no lasting damage. The decrease in F-v/F-m, however, was caused by a decrease in F-m and an increase in F-o in shade colonies suggesting photoinactivation and long-term cumulative photoinhibition. Shade colonies rapidly lost their symbiotic algae (bleached) during exposure to full sunlight. This study is consistent with the hypothesis that excess light leads to chronic damage of symbiotic dinoflagellates and their eventual removal from reef-building corals. It is significant that this can occur with high light conditions alone.

Telehealth and the diagnosis and management of cardiac disease

The financial and personal burden of chronic cardiac disease is high. Costs are likely to increase over the next few decades. Promising applications of telehealth have appeared in the diagnosis and management of cardiac disease and there are indications that telehealth services can improve the management of chronic cardiac disease as well as extend services to remote and rural populations. Telehealth has been applied to the capture of symptoms of cardiac disease with electrocardiography and echocardiography, to the management and rehabilitation of recently discharged patients, and in peer-to-peer consultation where remote expertise can facilitate diagnosis. Telehealth promises cost reductions in service delivery, although there is a need for properly controlled cost-effectiveness trials to underpin telehealth with a firm evidence base.

The Winnipeg principles, WTO and sustainable development: Proposed policies for reconciling trade and the environment

There is, a widespread belief that the WTO has made virtually no concessions to environmentalists about their concerns arising from free trade and the process of globalization. There are concerns that these processes may undermine prospects for sustainable development. Following, the United Nations Conference on Environment and Development held in Rio de Janeiro in 1992, the International Institute for Sustainable Development was established to advocate policies to support sustainable development within Canada and globally. In 1994, it proposed the Winnipeg Principles as. a means for reconciling international trade and development so as to: achieve sustainable development (ISD, 1994a,b). These seven principles are outlined in this article and assessed:. Although the International Institute for Sustainable Development had hoped: through these principles to influence the work programme of the Environment and Trade Committee of WTO, it seems to have little effect. Probably if these principles had been seriously considered by WTO, the serious social conflicts which emerged globally at the beginning of this century would have been avoided, and we would be in a better position to understand the complex links between trade, environment and sustainable development and adopt relevant policies. Copyright (C) 2001 John Wiley & Sons, Ltd and ERP Environment.

Globalisation and sustainability: environmental Kuznets curve and the WTO

Economic globalisation is seen by many as a driving force for global economic growth. Yet opinion is divided about the benefits of this process, as highlighted by the WTO meeting in Seattle in late 1999. Proponents of economic globalisation view it as a positive force for environmental improvement and as a major factor increasing the likelihood of sustainable development through its likely boost to global investment. These proponents mostly appeal to analysis based on the environmental Kuznets curve (EKC) to support their views about environmental improvement. But EKC-analysis has significant deficiencies. Furthermore, it is impossible to be confident that the process of economic globalisation will result in sustainable development, if 'weak conditions' only are satisfied. 'Strong conditions' probably need to be satisfied to achieve sustainable development, and given current global institutional arrangements, these are likely to be violated by the economic globalisation process. Global political action seems to be needed-to avert a deterioration in the global environment and to prevent unsustainability of development. This exposition demonstrates the limitations of EKC-analysis, identifies positive and negative effects of economic globalisation on pollution levels, and highlights connections between globalisation and the debate about whether strong or weak conditions are required for sustainable development. The article concludes with a short discussion of the position of WTO in relation to trade and the environment and the seemingly de facto endorsement of WTO of weak conditions for sustainable development. It suggests that WTO's relative neglect of environmental concerns is no longer politically tenable and needs to be reassessed in the light of recent developments in economic analysis. The skew of economic growth, e.g. in favour of developing countries, is shown to be extremely important from a global environmental perspective. (C) 2001 Elsevier Science B.V. All rights reserved.

Review of 'Hearts and minds: Creative Australians and the environment'

Reviews the book `Hearts and Minds: Creative Australians and the Environment,' by Michael Pollak and Margaret MacNabb

Evaluation of synergistic interactions between the Colorado potato beetle (Coleoptera : Chrysomelidae) pathogen Beauveria bassiana and the insecticides, imidacloprid, and cyromazine

Laboratory studies investigated the interaction between the fungal entomopathogen Beauveria bassiana (Balsamo) Vuillemin and sublethal doses of the insecticides imidacloprid and cyromazine when applied to larvae of the Colorado potato beetle, Leptinotarsa decemlinenta (Say). When second instars were fed potato leaf discs treated with sublethal doses of imidacloprid and a range of doses of B. bassiana, a synergistic action was demonstrated. Similar results were observed when larvae were sprayed directly with B. bassiana conidia and immediately fed leaf discs treated with imidacloprid. No synergistic interaction was detected when larvae were fed leaf discs treated with sublethal doses of imidacloprid 24 h after application of R. bassiana conidia to larvae. However, a synergistic interaction was detected when larvae were fed leaf discs treated with imidacloprid and sprayed with B, bassiana conidia 24 h later. Although sublethal doses of both imidacloprid and the triazine insect growth regulator (IGR) cyromazine prolonged the duration of the second instar, only imidacloprid interacted with B. bassiana to produce a synergistic response in larval mortality. In leaf consumption studies, the highest dose of B, bassiana tested promoted feeding in inoculated second instars. Feeding was inhibited when larvae were fed foliage treated with sublethal doses of imidacloprid and significantly reduced when fed foliage treated with a sublethal dose of cyromazine. Starvation of larvae for 24 h immediately after B. bassiana treatment produced a similar result to the combined treatment of B. bassiana and imidacloprid and increased the level of mycosis when compared with B. bassiana controls. Imidacloprid treatment affected neither the rate of germination of B. bassiana conidia on the insect cuticle nor the rate at which conidia were removed from the integument after application. The statistical analysis used to detect synergism and the possible role of starvation-induced stress factors underlying the observed synergistic interactions are discussed.

The City as Territory: Aerial Photography and the Everyday

For most of us, the modern city is somewhat unintelligible, both in terms of its structure and its significance. As an urbanised population, the city should be our natural territory, but the pace and scope of its change leads to an illegibility of its form and character. There is infinite, seemingly significant, activity - demolition, building and makeover - but there is little sense of the city as a site of meaning.

Highlights of drought policy and related science in Australia and the USA

Patterns of water supply and use in Australia and the U.S.A. differ in many ways. This results in different perceptions concerning the nature of drought and policy approaches to its management. This paper discusses the differences and similarities and explores lessons that policy makers in both countries can learn from one another. A key difference between the two countries is that whereas drought is perceived in Australia essentially in terms of its impact on agriculture, in the U.S. both perceptions and policy are also heavily influenced by the impact of drought on urban communities. This has led to different policy emphases. In 1992 Australia established its National Drought Policy; the U.S. is presently considering the adoption of a national drought policy. These policies highlight drought being accepted as part of natural climate variability, rather than as a natural disaster. They also emphasize the protection of the natural resource base.

SOX18 and the transcriptional regulation of blood vessel development

SOX18 is a transcription factor that is transiently expressed in nascent endothelial cells during embryonic development and adult neovascularization. This protein belongs to the SOX family of transcription factors, ih,which are proving to be some of the key regulators of cell-type specification in the vertebrate embryo. Natural mutations in the Sox18 gene have been shown to result to cardiovascular dysfunction, in some cases leading to death. Available evidence thus implicates Sox18 as an important regulator of vascular development, most likely playing a key role in endothelial cell specification. However; the genetic knockout of Sox18 in mice has produced a confounding result that complicates our understanding of the molecular mode of action of the SOX18 protein. We speculate that Sox18 inky act in a redundant fashion with closely related genes such as Sox7 and/or Sox17. (C) 2001, Elsevier Science Inc.