Cross-talk between caveolae and glycosylphosphatidylinositol-rich domains

Most mammalian cells have in their plasma membrane at least two types of lipid microdomains, non-invaginated lipid rafts and caveolae. Glycosylphosphatidylinositol (GPI)-anchored proteins constitute a class of proteins that are enriched in rafts but not caveolae at steady state. We have analyzed the effects of abolishing GPI biosynthesis on rafts, caveolae, and cholesterol levels. GPI-deficient cells were obtained by screening for resistance to the pore-forming toxin aerolysin, which uses this class of proteins as receptors. Despite the absence of GPI-anchored proteins, mutant cells still contained lipid rafts, indicating that GPI-anchored proteins are not crucial structural elements of these domains. Interestingly, the caveolae-specific membrane proteins, caveolin-1 and 2, were up-regulated in GPI-deficient cells, in contrast to flotillin-I and GM1, which were expressed at normal levels. Additionally, the number of surface caveolae was increased. This effect was specific since recovery of GPI biosynthesis by gene recomplementation restored caveolin expression and the number of surface caveolae to wild type levels. The inverse correlation between the expression of GPI-anchored proteins and caveolin-1 was confirmed by the observation that overexpression of caveolin-1 in wild type cells led to a decrease in the expression of GPI-anchored proteins. In cells lacking caveolae, the absence of GPI-anchored proteins caused an increase in cholesterol levels, suggesting a possible role of GPI-anchored proteins in cholesterol homeostasis, which in some cells, such as Chinese hamster ovary cells, can be compensated by caveolin up-regulation.

The design of hazard risk assessment matrices for ranking occupational health risks and their application in mining and minerals processing

Two hazard risk assessment matrices for the ranking of occupational health risks are described. The qualitative matrix uses qualitative measures of probability and consequence to determine risk assessment codes for hazard-disease combinations. A walk-through survey of an underground metalliferous mine and concentrator is used to demonstrate how the qualitative matrix can be applied to determine priorities for the control of occupational health hazards. The semi-quantitative matrix uses attributable risk as a quantitative measure of probability and uses qualitative measures of consequence. A practical application of this matrix is the determination of occupational health priorities using existing epidemiological studies. Calculated attributable risks from epidemiological studies of hazard-disease combinations in mining and minerals processing are used as examples. These historic response data do not reflect the risks associated with current exposures. A method using current exposure data, known exposure-response relationships and the semi-quantitative matrix is proposed for more accurate and current risk rankings.

Economic and environmental impacts of pollution control in a system of environment and economic interdependence

The importance of the rate of change of the pollution stock in determining the damage to the environment has been an issue of increasing concern in the literature. This paper uses a three-sector (economy, population and environment), non-linear, discrete time, calibrated model to examine pollution control. The model explicitly links economic growth to the health of the environment. The stock of natural resources is affected by the rate of pollution flows, through their impact on the regenerative capacity of the natural resource stock. This can shed useful insights into pollution control strategies, particularly in developing countries where environmental resources are crucial for production in many sectors of the economy. Simulation exercises suggested that, under plausible assumptions, it is possible to reverse undesirable transient dynamics through pollution control expenditure, but this is dependent upon the strategies used for control. The best strategy is to spend money fostering the development of production technologies that reduce pollution rather than spending money dealing with the effects of the pollution flow into the environment. (C) 2001 Elsevier Science Ltd. All rights reserved.

The politics of reintegrating Australian Aboriginal and American Indian indigenous knowledge into resource management: The dynamics of resource appropriation and cultural revival

As the United States and Australia struggle with contemporary crises over competing uses of rapidly depleting natural resources, there are striking parallels between American Indian and Australian Aboriginal communities demanding a place at the management table and offering culturally based understandings of and solutions for the ecosystems at risk. These efforts to integrate indigenous knowledge into mainstream natural resource management are part of larger legal and political debates over land tenure, the locus of control, indigenous self-governance, and holistic ecosystems management.

Participation and older people: Meaning, theory and practice

Increasing older people's participation in society is important in ageing policies worldwide. There is a need to understand the challenges for health professionals of transforming policy on participation into liberating social change practices on the ground. This paper explores the meaning, theory and practice of participation. It uses the example of a work in progress project that has attempted to address structural barriers to older people's participation within an Australian aged care facility, to illustrate theoretical and practice principles surrounding participation.

The role of handouts, note-taking and overhead transparencies in veterinary science lectures

Objective To study student and staff views of the role and use of handouts, note-taking and overhead transparencies in veterinary science lectures at the University of Queensland Methods The Nominal Group Technique was used to help develop a questionnaire, which was completed by 351 students (a response rate of 84%) and 35 staff (76%) from the 5 years of the veterinary course. The data were analysed using the SAS statistical computer package. Results Staff and students held different views as to the frequency with which handouts should be used, their educational value, and whether they should be complete or partial. Fewer students than staff agreed that handouts discourage further reading in a subject. Almost all staff and students saw the central functions of note-taking to be provision of notes for subsequent revision and encoding information given by the lecturer. More students than staff however, considered that note-taking in lectures interferes with understanding. Staff and students held similar views as to the uses of overheads in lectures. Interestingly however, more staff than students agreed that overheads often contain too much information. Conclusion Both students and staff saw the central role of note-taking as providing a set of good notes for revision. Generally students preferred that this information be provided in the form of partial or complete handouts, while staff preferred students to take notes and to read outside lectures. Surprisingly, more staff than students felt that overhead transparencies often contained too much information. Note-taking, handouts and overhead transparencies need to be linked in a coherent educational strategy to promote effective learning.

Discovery and structures of the cyclotides: novel macrocyclic peptides from plants

Circular disulfide-rich polypeptides were unknown a decade ago but over recent years a large family of such molecules has been discovered, which we now refer to as the cyclotides. They are typically about 30 amino acids in size, contain an N- to C-cyclised backbone and incorporate three disulfide bonds arranged in a cystine knot motif. In this motif, an embedded ring in the structure formed by two disulfide bonds and their connecting backbone segments is penetrated by the third disulfide bond. The combination of this knotted and strongly braced structure with a circular backbone renders the cyclotides impervious to enzymatic breakdown and makes them exceptionally stable. This article describes the discovery of the cyclotides in plants from the Rubiaceae and Violaceae families, their chemical synthesis, folding, structural characterisation, and biosynthetic origin. The cyclotides have a diverse range of biological applications, ranging from uterotonic action, to anti-HIV and neurotensin antagonism. Certain plants from which they are derived have a history of uses in native medicine, with activity being observed after oral ingestion of a tea made from the plants. This suggests the possibility that the cyclotides may be orally bioavailable. They therefore have a range of potential applications as a stable peptide framework.

Remitting behaviour of Nepalese rural-to-urban migrants: Implications for theory and policy

This article uses data for Nepal to test contemporary hypotheses about the remitting behaviour and associated motives of rural-to-urban migrants and to consider the likely impact of such remittances on rural development. Possibilities for inheritance, degree of family attachment, likelihood of eventual return to place of origin and family investment in the education of the migrants are found to be significant influences on levels of remittances by Nepalese migrants. However, in Nepal, remittances do not seem to result in long-term capital investment in rural areas and so may not promote long-term development of these areas.

The therapeutic potential of dopamine modulators on the cardiovascular and renal systems

In the periphery, physiological dopamine increases renal blood flow, decreases renal resistance and acts on the kidney tubule to enhance natriuresis and diuresis. The loss of dopamine function may be involoved in the deterioration in kidney function associated with ageing and may have a role in the pathogenesis of hypertension and diabetes. Intravenous dopamine is used as a positive inotrope in the treatment of acute heart failure and cardiogenic shock and as a diuretic in renal failure. The clinical uses of dopamine are limited, as it must be given intravenously, and also has widespread effects. The levels of peripheral dopamine can be increased by the administration of L-dopa to increase synthesis, prodrugs to release dopamine (docarpamine, glu-dopa) or by inhibiting the breakdown of dopamine (nitecapone). Preliminary clinical trials suggest that docarpamine may be useful in patients with low cardiac output syndrome after cardiac surgery and in refractory cirrhotic ascites. Ibopamine is an agonist at dopamine D1 and D2 receptors, which may retard the progression of chronic renal failure. Gludopa is selective for the kidney thus avoiding widespread side effects. The early clinical studies with ibopamine as a diuretic in heart failure were favourable but the subsequent large mortality study showed that ibopamine increased mortality. Fenoldopam is a selective dopamine D1 receptor agonist. Intravenous fenoldopam may be useful in the treatment of hypertension associated with coronary artery bypass surgery or in hypertensive emergencies. Although our understanding of physiological and pathological roles of peripheral dopamine has been increasing rapidly in recent times, we still need more information to allow the design of clinically useful drugs that modify these roles. One priority is an orally-active selective dopamine D1 receptor agonist.

Discovering the Law Again: John Grisham, Ed Stevens and the Postmaterial Lawyer

This paper uses three films adapted from the novels of John Grisham, The Firm, The Rainmaker and A Time To Kill, as well as associated television series like Ed to map a vernacular theory of what I have termed the 'postmaterial' lawyer. Grisham's work has been the focus of much critique by legal scholars who suggests he hates lawyers, is critical of the concept of law, and provides 'outlandishly' happy endings. I will challenge these critiques and, in tracing the history of legal thrillers and trial movies, suggest that Grisham and the related texts' explorations of how a just practitioner can operate in an unjust system constitute a powerful interrogation of what law can be.

Mitigated directness in Honglou meng: directive speech acts and politeness in eighteenth century Chinese

This paper is situated within a theoretical discussion that asserts a positive correlation between indirectness and politeness, and uses these claims as a springboard for an examination of polite ways of issuing directives in eighteenth century Chinese. On the basis of an analysis of directive speech acts from dialogue in the novel Honglou meng, it argues that the concept of indirectness, as it applies to the illocutionary transparency of individual speech acts, has no particular value in the culture and language of eighteenth century Chinese men. It is found that other linguistic devices such as particles, the reduplication of verbs, terms of address, and the presence and sequencing of supportive moves are far more significant to the communication of politeness. The findings suggest a need to rethink current theoretical positions on this subject and move beyond the analysis of individual speech acts to examine the role discourse structure and management play in the enactment of politeness. (C) 2002 Elsevier Science B.V. All rights reserved.

Brazil and the nuclear issues in the years of the Luiz Inácio Lula da Silva government (2003-2010)

The present article is an analysis of Brazilian nuclear diplomacy and of the international relevance of the national nuclear program adopted during the two Presidential terms of Luiz Inácio Lula da Silva. Particular attention will be given to the Brazilian position in the agreement on nuclear non-proliferation, to the role of mediation between Iran and the nuclear powers, and finally to the national ambitions concerning the industrial and military uses of the nuclear technologies.

The essential role of democracy in the Bush Doctrine: the invasions of Iraq and Afghanistan

Everyone knows that democracy played a role in the Bush Doctrine. What not everyone knows is that this role was essential for the doctrine to be put into operation under which the Iraq invasion was prepared and launched. We argue moreover that, even if aggressive, the Bush doctrine is compatible with the American Liberal Tradition. To demonstrate these arguments we analyze the links between democracy, security, and the US national interests as expressed in the pillars of the American foreign policy since the end of Cold War. The consequential belief of the Bush Administration on the positive effect of exporting democracy by the use of force to Afghanistan and Iraq to fight terrorism will be remarked. It will be shown, however, that in the first years of the Bush Administration, among the justifications for the military interventions in the two countries, security reasons prevailed over democratic concerns, although the latter was significantly present since the early hours after September 11. It was only when it became clear that WMDs did not exist in Iraq that the exporting of democracy as the ultimate weapon to fight terrorism grew remarkably and prevailed over security reasons to invade those rogue states. The paper uses quantitative and qualitative content analysis of the speeches of President Bush and his Secretaries of State and Defense.

Discourses of cyberspace securitization in Brazil and in the United States

Abstract This paper uses the framework of the Copenhagen School to understand the process of securitization of cyberspace, exploring how something in such sphere becomes a threat. Seeking to contribute to the debate, this study analyses the securitization discourses of Brazil and of the United States from Hansen and Nissenbaum's (2009) theorization about the existence of a specific sector for cybersecurity. To comprehend the securitization of cyberspace in these terms allows not only to identify distinct levels of securitization, but also to capture the dynamics of cyber threats, distinguishing them from those existent in other sectors, as well as to trace distinctions between tendencies of securitization and militarization.

Morphological, physical and pedogenetic attributes related to water yield in small watersheds in Guarapari/ES, Brazil

Soil characteristics related to the genesis, land use and management are important factors in water dynamics in watersheds. This study evaluated physical, morphological and pedogenetic attributes related to water yield potential in small watersheds in Guarapari, ES, Brazil. The following representative profiles were selected, morphologically described and sampled in area of Atlantic Forest domain: Lithic Udifolists, Oxyaquic Udifluventes, Typic Paleudults, Typic Hapludults, Typic Hapludox, Oxic Dystrudepts and Typic Endoaquents. Samples were collected in the soil profiles for physical analysis. Measurements of field-saturated hydraulic conductivity and soil penetration resistance were perfomed in some profiles, which were under different uses. The Endoaquents of Limão Creek can be considered efficient as temporary water reservoirs. However, the use of artificial drainage tends to reduce this effect. Differential erosion was detected by the sand texture on the surface of the Typic Paleudults due to the low degree of clay flocculation, slope, high resistance to the penetration and low hydraulic conductivity of the Bt horizon, making it necessary to adopt soil management practices to increase the water infiltration. Under pasture, mainly in the cattle trails where the trampling is more intense, there was high resistance to penetration in the superficial layers of the Typic Hapludults. The Typic Hapludox have the greatest potential for water yield in the small watersheds because of its greater extent in the headwaters and their morphological and physical characteristics, which can result in increased aquifer recharge.