1,333 research outputs found
The chronostratigraphy of the Anthropocene in southern Africa: Current status and potential
The process for the formal ratification of the proposed Anthropocene Epoch involves the identification of a globally isochronous stratigraphic signal to mark its starting point. The search for a Global Boundary Stratotype Section and Point (GSSP), a unique reference sequence that would be used to fix the start of the epoch, is in progress but none of the candidate sections are located in Africa. We assessed the currently available stratigraphic evidence for the possible markers of the Anthropocene in southern Africa and found that, although most markers have been identified in the region, the robustly dated, high resolution records required for the GSSP are very sparse. We then assessed the extent and stratigraphic resolution of a range of potential natural archives and conclude that a small number of permanent lakes, as well as marine sediments, corals and peats from selected locations in southern Africa could provide the temporal resolution required. With sufficient chronological control and multi-proxy analyses, one of these archives could provide a useful auxiliary stratotype thereby helping to confirm the global reach, and extending the utility, of the selected Anthropocene GSSP
Adapting to climate risks and extreme weather: a guide for mining and minerals industry professionals
Abstract Extreme weather events in Australia over recent years have highlighted the costs for Australian mining and mineral processing operations of being under-prepared for adapting to climate risk. For example, the 2010/2011 Queensland floods closed or restricted production of about forty out of Queenslands fifty coal mines costing more than $2 billion in lost production. Whilst mining and mineral professionals have experience with risk management and managing workplace health and safety, changes to patterns of extreme weather events and future climate impacts are unpredictable. Responding to these challenges requires planning and preparation for events that many people have never experienced before. With increasing investor and public concern for the impact of such events, this guide is aimed at assisting a wide range of mining and mineral industry professionals to incorporate planning and management of extreme weather events and impacts from climate change into pre-development, development and construction, mining and processing operations and post-mining phases. The guide should be read in conjunction with the research final report which describes the research process for developing the guide and reflects on challenges and lessons for adaptation research from the project. The Institute for Sustainable Futures, University of Technology Sydney (UTS) led the development of the guide with input from the Centre for Mined Land Rehabilitation, University of Queensland and a Steering Committee from the Australasian Institute of Mining and Metallurgys Sustainability Committee and individual AusIMM members, who volunteered their time and experience. As the situation of every mining and mineral production operation is going to be different, this guide has been designed to provide general information about the nature of extreme weather events, and some specific examples of how unexpectedly severe flooding, storm, drought, high temperature and bushfire events have affected mining and mineral processing operations. A number of case studies used throughout the guide also illustrate the ways forward thinking operations have tackled dramatically changing climatic conditions. Each section of the guide outlines a range of direct and indirect impacts from a different type of extreme weather, and provides a starting point for identifying potential risks and adaptation options that can be applied in different situations. The impacts and adaptation sections provide guidance on putting the key steps into practice by detailing specific case examples of leading practice and how a risk management approach can be linked to adaptive planning. More information about specific aspects of extreme weather, planning and preparation for the risks presented by these events, and tools for undertaking climate related adaptation is provided in the `Additional Resources section
Effect of light-touch intervention and associated factors to microbial contamination at small-scale pig slaughterhouses and traditional pork shops in Vietnam
Traditional pork value chains dominate the production and distribution of pork in Vietnam; however, the high level of microbiological contamination in pork may increase the risk of food-borne disease for consumers. There is limited evidence about how to feasibly and scalably reduce microbial contamination in pork sold in traditional markets. This study aimed to assess the effectiveness of light-touch interventions for changing worker behaviour in small-scale slaughterhouses and vendors at traditional pork shops, as well as to identify risk factors for pork contamination. The intervention packages consisted of providing hygiene tools and delivering a food safety training which had been designed in a participatory way and covered 10 small-scale slaughterhouses and 29 pork shops. Pig carcasses, retailed pork, contact surfaces, and hands were sampled to measure the total bacterial count (TBC) and Salmonella contamination before, three and six weeks after the intervention, and trainee practices were observed at the same time. Linear and generalized linear mixed effects models were constructed to identify risk factors for TBC and Salmonella contamination at the slaughterhouses and pork shops. The interventions at slaughterhouses and pork shops both showed a slight reduction of TBC contamination in pig carcasses and Salmonella prevalence in retailed pork, while the TBC in retailed pork decreased only marginally. For slaugh-terhouses, the regression model indicated that smoking or eating during slaughtering (indicating poor hygienic practices) was associated with TBC increasing, while cleaning floors and wearing boots reduced TBC contami-nation. For pork shops, using rough materials (cardboard or wood) to display pork was the only factor increasing TBC contamination in pork, whereas cleaning knives was associated with lower TBC. Besides, the presence of supporters and wearing aprons reduced the probability of Salmonella contamination in pork. The findings highlight the effectiveness of light-touch interventions in reducing microbial contamination in pig carcasses at small-scale slaughterhouses and pork at traditional shops over the study period
Propagation of ultrahigh energy nuclei in clusters of galaxies: resulting composition and secondary emissions
We study the survival of ultrahigh energy nuclei injected in clusters of
galaxies, as well as their secondary neutrino and photon emissions, using a
complete numerical propagation method and a realistic modeling of the magnetic,
baryonic and photonic backgrounds. It is found that the survival of heavy
nuclei highly depends on the injection position and on the profile of the
magnetic field. Taking into account the limited lifetime of the central source
could also lead in some cases to the detection of a cosmic ray afterglow,
temporally decorrelated from neutrino and gamma ray emissions.
We calculate that the diffusive neutrino flux around 1 PeV coming from
clusters of galaxies may have a chance to be detected by current instruments.
The observation of single sources in neutrinos and in gamma rays produced by
ultrahigh energy cosmic rays will be more difficult. Signals coming from lower
energy cosmic rays (E < 1 PeV), if they exist, might however be detected by
Fermi, for reasonable sets of parameters.Comment: 19 pages, 15 figures, version to appear in ApJ (minor changes
Color Confinement, Quark Pair Creation and Dynamical Chiral-Symmetry Breaking in the Dual Ginzburg-Landau Theory
We study the color confinement, the - pair creation and the
dynamical chiral-symmetry breaking of nonperturbative QCD by using the dual
Ginzburg-Landau theory, where QCD-monopole condensation plays an essential role
on the nonperturbative dynamics in the infrared region. As a result of the dual
Meissner effect, the linear static quark potential, which characterizes the
quark confinement, is obtained in the long distance within the quenched
approximation. We obtain a simple expression for the string tension similar to
the energy per unit length of a vortex in the superconductivity physics. The
dynamical effect of light quarks on the quark confining potential is
investigated in terms of the infrared screening effect due to the -
pair creation or the cut of the hadronic string. The screening length of the
potential is estimated by using the Schwinger formula for the - pair
creation. We introduce the corresponding infrared cutoff to the strong
long-range correlation factor in the gluon propagator as a dynamical effect of
light quarks, and obtain a compact formula of the quark potential including the
screening effect in the infrared region. We investigate the dynamical
chiral-symmetry breaking by using the Schwinger-Dyson equation, where the gluon
propagator includes the nonperturbative effect related toComment: 37 pages, plain TeX (using `phyzzx' macro), (( 8 figures - available
on request from [email protected] )
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