44 resultados para global heading changes

em Deakin Research Online - Australia


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New 87Sr/86Sr data based on 127 well-preserved and well-dated conodont samples from South China were measured using a new technique (LA-MC-ICPMS) based on single conodont albid crown analysis. These reveal a spectacular climb in seawater 87Sr/86Sr ratios during the Early Triassic that was the most rapid of the Phanerozoic. The rapid increase began in Bed 25 of the Meishan section (GSSP of the Permian-Triassic boundary, PTB), and coincided closely with the latest Permian extinction. Modeling results indicate that the accelerated rise of 87Sr/86Sr ratios can be ascribed to a rapid increase (>2.8×) of riverine flux of Sr caused by intensified weathering. This phenomenon could in turn be related to an intensification of warming-driven runoff and vegetation die-off. Continued rise of 87Sr/86Sr ratios in the Early Triassic indicates that continental weathering rates were enhanced >1.9 times compared to those of the Late Permian. Continental weathering rates began to decline in the middle-late Spathian, which may have played a role in the decrease of oceanic anoxia and recovery of marine benthos. The 87Sr/86Sr values decline gradually into the Middle Triassic to an equilibrium values around 1.2 times those of the Late Permian level, suggesting that vegetation coverage did not attain pre-extinction levels thereby allowing higher runoff.

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The Late Palaeozoic Ice Age (LPIA), spanning approximately from ~320 Ma (Serpukhovian, late Mississippian) to 290 Ma (mid-Sakmarian, Early Permian), represents the vegetated Earth’s largest and most long-lasting regime of severe and multiple glaciations, involving processes and patterns probably comparable to those of the Last Ice Age. Accompanying the LPIA occurred a number of broadly synchronous global environmental and biotic changes. These global changes, as briefly reviewed and summarized in this introductory paper, comprised (but are not limited to) the following: massive continental reorganization in the lead up to the final assembly of Pangea resulting in profound changes in global palaeogeography, palaeoceanography and palaeobiogeogarphy; substantially lowered global atmospheric carbon dioxide concentrations (pCO2), coupled with an unprecedented increase in atmospheric oxygen concentrations reaching Earth's all-time high in its last 600 million year history; sharp global temperature and sea-level drops (albeit with considerable spatial and temporal variability throughout the ice age); and apparently a prolonged period of global sluggish macro-evolution with both low extinction and origination rates compared to other times. In the aftermath of the LPIA, the world's climate entered into a transitional climate phase through the late Early to Middle Permian before its transformation into a greenhouse state towards the end-Permian. In recent years, considerable amount of data and interpretations have been published concerning the physical evidence in support of the LPIA, its broad timeframe and eustatic and ecosystem responses from the lower latitudes, but relatively less attention has been drawn to the impact of the ice age on late Palaeozoic high-latitude environments and biotas. It is with this mission in mind that we have organized this special issue, with the central focus on late Palaeozoic high latitude regions of both hemispheres, that is, Gondwana and northern Eurasia. Our aim is to gather a set of papers that not only document the physical environmental changes that had occurred in the polar regions of Gondwana and northern Eurasia during the LPIA, but also review on the biotic responses at different taxonomic, ecological and spatial scales to these physical changes in a refined chronological timeframe.

This introductory paper is designed to provide a global context for the special issue, with a brief review of key late Palaeozoic global environmental changes (including: changes in global land-sea configurations, atmospheric chemistry, global climate regimes, global ocean circulation patterns and sea levels) and large -scale biotic (biogeographic and evolutionary) responses, followed by a summary of what we see as unresolved scientific issues and various working hypotheses concerning late Palaeozoic global changes and, in particular, the LPIA, as a possible reference to future research.

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Plants modify metabolic processes for adaptation to low phosphate (P) conditions. Whilst transcriptomic analyses show that P deficiency changes hundreds of genes related to various metabolic processes, there is limited information available for global metabolite changes of P-deficient plants, especially for cereals. As changes in metabolites are the ultimate ‘readout’ of changes in gene expression, we profiled polar metabolites from both shoots and roots of P-deficient barley (Hordeum vulgare) using gas chromatography–mass spectrometry (GC-MS). The results showed that mildly P-deficient plants accumulated di- and trisaccharides (sucrose, maltose, raffinose and 6-kestose), especially in shoots. Severe P deficiency increased the levels of metabolites related to ammonium metabolism in addition to di- and trisaccharides, but reduced the levels of phosphorylated intermediates (glucose-6-P, fructose-6-P, inositol-1-P and glycerol-3-P) and organic acids (α-ketoglutarate, succinate, fumarate and malate). The results revealed that P-deficient plants modify carbohydrate metabolism initially to reduce P consumption, and salvage P from small P-containing metabolites when P deficiency is severe, which consequently reduced levels of organic acids in the tricarboxylic acid (TCA) cycle. The extent of the effect of severe P deficiency on ammonium metabolism was also revealed by liquid chromatography–mass spectrometry (LC-MS) quantitative analysis of free amino acids. A sharp increase in the concentrations of glutamine and asparagine was observed in both shoots and roots of severely P-deficient plants. Based on these data, a strategy for improving the ability of cereals to adapt to low P environments is proposed that involves alteration in partitioning of carbohydrates into organic acids and amino acids to enable more efficient utilization of carbon in P-deficient plants.

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The analysis and researches of many scholars and field specialists have gone into these 30 papers. They discuss many of the environmental problems and challenges to human life and existence presented by local and other exploitations and ongoing developments in Southeast Asian countries and marine areas. The authors use tabulated data and unpublished research in the eight sections on: underlying societal drivers and responses to environmental change; climate change and air quality; land transformation and its consequences; hydrology and hydrological cycles; changes in coastal and marine environments; vulnerabilities and adaptations to global environmental changes; and a final paper on a common need for action. This important volume includes reference, data, bibliographies and index.

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We investigated the Holocene palaeo-environmental record of the Tuggerah Lake barrier estuary on the south-east coast of Australia to determine the influence of local, regional and global environmental changes on estuary development. Using multi-proxy approaches, we identified significant down-core variation in sediment cores relating to sea-level rise and regional climate change. Following erosion of the antecedent land surface during the post-glacial marine transgression, sediment began to accumulate at the more seaward location at ~8500. years before present, some 1500. years prior to barrier emplacement and ~4000. years earlier than at the landward site. The delay in sediment accumulation at the landward site was a consequence of exposure to wave action prior to barrier emplacement, and due to high river flows of the mid-Holocene post-barrier emplacement. As a consequence of the mid-Holocene reduction in river flows, coupled with a moderate decline in sea-level, the lake experienced major changes in conditions at ~4000. years before present. The entrance channel connecting the lake with the ocean became periodically constricted, producing cyclic alternation between intervals of fluvial- and marine-dominated conditions. Overall, this study provides a detailed, multi-proxy investigation of the physical evolution of Tuggerah Lake with causative environmental processes that have influenced development of the estuary.

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BACKGROUND: Previous research showed an increase in Australian suicide rates during the Global Financial Crisis (GFC). There has been no research investigating whether suicide rates by occupational class changed during the GFC. The aim of this study was to investigate whether the GFC-associated increase in suicide rates in employed Australians may have masked changes by occupational class.

METHODS: Negative binomial regression models were used to investigate Rate Ratios (RRs) in suicide by occupational class. Years of the GFC (2007, 2008, 2009) were compared to the baseline years 2001-2006.

RESULTS: There were widening disparities between a number of the lower class occupations and the highest class occupations during the years 2007, 2008, and 2009 for males, but less evidence of differences for females.

CONCLUSIONS: Occupational disparities in suicide rates widened over the GFC period. There is a need for programs to be responsive to economic downturns, and to prioritise the occupational groups most affected.

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This paper emerges from research to define the dimensions of diversity and difference within a local Melbourne, Australian school and the requirement to understand these changes in times of increasing globalisation.

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The purpose of a thought experiment, as the term was used by quantum and relativity physicists in the early part of the twentieth century, was not prediction (as is the goal of classical experimental science), but more defensible representations of present ‘realities’. Speculative fictions, from Mary Shelley's Frankenstein to the Star Wars cinema saga, can be read as sociotechnical thought experiments that produce alternative representations of present circumstances and uncertainties, and anticipate and critique possible futures. In this essay I demonstrate how two examples of popular speculative fictions, Frank Herbert's Dune (1965) and Ursula Le Guin's The Telling (2000), function as thought experiments that problematise global transitions in their respective eras. I argue that critical readings of such stories can help us to anticipate, critique, and respond constructively to social and cultural changes and change environments within nation-states that constitute, and are constituted by, global change processes and their effects.

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This article categorizes four kinds of adverse effects to human health caused by ecosystem change: direct, mediated, modulated, and systems failure. The effects are categorized on their scale, complexity, and lag-time. Some but not all of these can be classified as resulting from reduced ecosystem services. The articles also explores the impacts that different socioeconomic–ecologic scenarios are likely to have on human health and how changes to human health may, in turn, influence the unfolding of four different plausible future scenarios. We provide examples to show that our categorization is a useful taxonomy for understanding the complex relationships between ecosystems and human well-being and for predicting how future ecosystem changes may affect human health.

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The rapidly increasing construction demand in China, particularly spurred by the coming 2008 Beijing Olympic Games and the 2010 Shanghai Expo, provides challenging opportunities for overseas construction enterprises. Therefore understanding the structure and dynamics of construction industry in China is crucial, particularly the potential changes of the market after the China's entry into the World Trade Organization. This paper analyses the development of construction economics and institutional regulations in the construction market, and provides a comprehensive image on the Chinese construction sector in the global environment.

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There is increasing evidence to suggest that reduced folate status may be a causative factor in carcinogenesis, particularly colorectal carcinogenesis. Folate is essential for the synthesis of S-adenosylmethionine, the methyl donor required for all methylation reactions in the cell, including the methylation of DNA. Global DNA hypomethylation appears to be an early, and consistent, molecular event in carcinogenesis. We have examined the effects of folate depletion on human-derived cultured colon carcinoma cells using 2 novel modifications to the Comet (single cell gel electrophoresis) assay to detect global DNA hypomethylation and gene region–specific DNA hypomethylation. Colon cells cultured in folate-free medium for 14 d showed a significant increase in global DNA hypomethylation compared with cells grown in medium containing 3µmol/L folic acid. This was also true at a gene level, with folate-deprived cells showing significantly more DNA hypomethylation in the region of the p53 gene. In both cases, the effects of folate depletion were completely reversed by the reintroduction of folic acid to the cells. These results confirm that decreased folate levels are capable of inducing DNA hypomethylation in colon cells and particularly in the region of the p53 gene, suggesting that a more optimal folate status in vivo may normalize any DNA hypomethylation, offering potential protective effects against carcinogenesis. This study also introduces 2 novel functional biomarkers of DNA hypomethylation and demonstrates their suitability to detect folate depletion–induced molecular changes.

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Debates over the merits and demerits of globalisation for health are increasingly polarised. Conclusions range from globalisation being essentially positive for health, albeit with a need to smooth out some rough edges, to one of utter condemnation, with adverse effects on the majority of the world's population. Anyone wading into this debate is immediately confronted by seemingly irreconcilable differences in ideology, opinion and interests. Both camps agree that global changes are occurring, and with them many of the determinants of population health status. While some skepticism persists about whether “globalisation” has value beyond being a fashionable buzzword, most agree that we need better understanding of these changes. Two difficult questions arise: (i) What are the health impacts of these changes; and (ii) how can we respond more effectively to them? To move beyond the stand-offs that have already formed within the health community, this paper reviews the main empirical evidence that currently exists, summarises key points of debate that remain, and suggests some ways forward for the research and policy communities. In particular, there is need for an informed and inclusive debate about the positive and negative health consequences of globalisation.

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Radical changes in the biosphere and human interaction with the environment are increasingly impacting on the health of populations across the world. Diseases are crossing the species barrier, and spreading rapidly through globalized transport systems. From new patterns of cancer to the threat of global pandemics, it is imperative that public health practitioners acknowledge the interdependence between the sustainability of the environment and the sustainability of the human species.* Why are issues of global and local sustainability of increasing importance to the public's health?* Why do issues of sustainability require new practices within the professions of public health?* How can future and current public health practitioners develop those new practices?Drawing on scientific evidence of global and local environmental changes, Sustainability and Health offers a thorough background and practical solutions to the overlapping issues in environment and health. It examines potential and existing responses to global and local environment and health issues, involving individuals, community, industry and government. The authors introduce a range of emerging conceptual frameworks and theoretical perspectives, link IT and epidemiology and explain how scoping can link program design, delivery, data collection and evaluation in projects from their very beginning. Public health practitioners need to be able to manage health issues that cut across environmental, economic and social systems and to develop the capacity for leadership in facilitating change. Incorporating learning activities, readings, international case studies and an open learning approach, this is a valuable resource for students of public and environmental health, as well as medical, environmental and health science professionals.

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In modern times, not many primary industries have consistently recorded high yearly growth over a period of two decades. Aquaculture has sustained a global growth, continues to grow, and is expected to increasingly fill the shortfall in aquatic food products resulting from static or declining capture fisheries and population increase well into the year 2025. Its further growth and development will have to occur under a different socio-economic milieu in the new millennium. The basic paradigm changes will be from an increased production at almost any cost, to a sustainable increase in production with minimal environmental perturbations. Despite such paradigm changes, aquaculture will increasingly contribute to food security, poverty alleviation and social equity. The contribution of aquaculture to world food supply of aquatic products has been increasing over the past 10 years, in comparison to capture fisheries, growing from 15 to 28 percent of total production between 1988 and 1997. As the bulk of aquaculture is rural and subsistence, it plays a major role as a provider of direct and indirect employment to the rural poor and, thereby, to poverty alleviation. In many developing countries, aquaculture provides opportunities for diversification on agriculture farms and productive use to otherwise idle land during certain seasons. The main cause for the upsurge in the sector has been the transformation of aquaculture from an “art” form to a “science”. This brought many advantages, ranging from less dependence on wild stock to the development of techniques that optimized yields, such as polyculture, or enabled the achievement of high yields with low inputs. Two major developments also enabled the sector to maintain growth momentum, appropriate institutional frameworks and concerted research and development. Regions or continents have many commonalities. These include the predominance of finfish among the cultivated species, and the predominance of species that feed lower in the food chain, although shrimp, which does not naturally feed high in the trophic level but is mostly reared on artificial feed, has become a significant culture commodity. Notable differences, however, include the fact that all regions, except Africa and the countries of the former USSR, have recorded a significant increase in per capita production between 1984 and 1997. While Asia continues to dominate world aquaculture in overall tonnage, as well as in every major commodity, South America has registered a very high (72.8 percent) average annual growth between 1984 and 1997. The global and regional trends over the last 20 years in the sector from a number of perspectives, such as production trends, contribution of aquaculture to aquatic food consumption etc., are evaluated. Based on these different trends and in the light of changing socio-economic conditions globally, and in particular, in developing nations, the potential changes in the sector in the new millennium are highlighted. Finally, projections are made for the next 20 years, where opportunities, constraints and strategies for achieving the targets are presented and discussed.

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‘In these troubled times with the world in search of its bearings and way ward minds using the terms “culture” and “civilization” in an attempt to turn human beings against one another, there is an urgent need to remember how fundamental cultural diversity is to humanity itself’ (UNESCO 2002). The progressive idea of culture can be used in regressive ways by extremists who used it occasionally to pursue the politics of xenophobia and exclusion. The hypothesis that different communities can share the same culture but have different visual perception of their built environment might seems contradictory. It is essential to describe what is meant by the ‘same culture’. The ever evolving changes of definition and re-definition of the word has not yet settled. This paper adopts the descriptive definition of culture while challenging its interpretation. The descriptive definition refers to ‘all the characteristics activities by a people’. While this description is generally accepted, the interpretation of what ‘a people’ means is divisive. It is not clear how Eliot defines ‘a people’. Is the term genetically prescribed or is ‘a people’ place related? And what about the moral and religious orientation? This paper argues that culture is basically place related and the forces that shape a culture of a ‘people’ are deeply embedded in the environmental forces that also shape other aspects of the place making and its identity. The paper addresses the questions of conflicts, value systems, and culture definitions and the inseparable links with architecture aesthetics.

Local built heritage in Northern Ireland is taken as a case study. Unlike many parts of the world, visual perceptions in Northern Ireland is well recognised with iconic as well as formal representations. The population is well aware of the signified as well as the signifiers. The boundaries between iconology and formalism theories are very blurred in the Northern Ireland context. This paper examines how the two communities visually perceive their shared built heritage and the extent of overlapping between the understanding of iconic and formalist visual representations in the built environment. The paper takes the buildings of the successful economic ventures of the shirt industry in the 19th century as a case study. The case study provides an insight of how a signified value of a successful economic regeneration initiative that is deeply imbedded in the social structure and within the urban fabric can overcome divisive visual perception. The paper examines the possibility of building upon the historical success of the shirt industry to promote architectural cultural dialogue in which cultural built heritage in Derry is able to facilitate knowledge creation and social capital in different arenas.