6,416 research outputs found

    Global water: issues and insights

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    This book brings together some of the world’s leading water researchers with an especially written collection of chapters on: water economics; transboundary water; water and development; water and energy; and water concepts. Introduction Freshwater governance holds a prominent position in the global policy agenda. Burgeoning water demand due to population growth and rising incomes is combining with supply-side pressures, such as environmental pollution and climate change, to create acute conditions of global water scarcity. This is a major concern because water is a primary input for agriculture, manufacturing, environmental health, human health, energy production and just about every economic sector and ecosystem. In addition to its importance, the management of freshwater resources is a complex, multidisciplinary topic. Encompassing a range of fields in the physical and social sciences, the task of sustainably meeting human and environmental water needs requires a depth and breadth of understanding unparalleled by most other policy problems. Our objective in this volume is to provide knowledge and insights into major issues and concepts related to freshwater governance. The book is divided into five themed parts: Economics, Transboundary governance, Development, Energy and Water Concepts. A part addresses each theme and opens with an introduction that provides an overview of key topics. For example, the introduction to the economics section presents two main foci: measuring the value of water and managing trade-offs between different water uses. The thematic case studies discuss issues such as water pricing in Organisation for Economic Co-operation and Development (OECD) countries, finance of water supply and irrigation infrastructure and improving agricultural production with enhanced water management. The aim of the volume is to accessibly communicate academic research from the many fields of freshwater governance. Too often, academic research is paywalled and/or written in a style that caters to colleagues in the same field, rather than a broader audience from other disciplines, the policy-making community and the general public. This open-access book presents the research of a range of global experts on freshwater governance in brief, insightful chapters that do not presume a high level of pre-existing knowledge of their respective subjects. This format is intended to present knowledge on the key problems of and solutions to global freshwater challenges. The final part presents research from several United Nations Educational, Social, and Cultural Organisation (UNESCO) supported water research Chairs and Centres. Support and coordination of the insititutions highlighted in this part of the book is provided by UNESCO. One water research Chair is The Australian National University – UNESCO Chair in Water Economics and Transboundary Governance, which was established in April 2010 and works with partners in southern Africa, UNESCO, the Global Water Partnership and other organisations to: (1) increase the skills, capacity, networks and potential of leaders and prospective water managers and policy-makers; (2) sustain and strengthen institutional capacity (especially in southern Africa) by providing a platform for collaboration and institutional development; and, (3) develop innovative research, tools, case-studies, and insights on water economics, water governance and equity. Established by the ANU–UNESCO Chair, the Global Water Forum (GWF) seeks to disseminate knowledge regarding freshwater governance and build the capacity of students, policy-makers and the general public to respond to local and global water issues. The GWF publishes accessible, subscription-free articles highlighing the latest research and practice concerning freshwater governance. A broad range of water-related topics are discussed in a non-technical manner, including water security, development, agriculture, energy and environment. In addition to publishing articles, reports and books, the GWF is engaged in a range of activities, such as the annual Emerging Scholars Award and hosting a portal to educational resources on freshwater. We hope that you enjoy reading this book and, more importantly, gain an improved understanding of the complex freshwater-governance challenges facing us all on a global scale and at a local level

    "Interaction-Free" Imaging

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    Using the complementary wave- and particle-like natures of photons, it is possible to make ``interaction-free'' measurements where the presence of an object can be determined with no photons being absorbed. We investigated several ``interaction-free'' imaging systems, i.e. systems that allow optical imaging of photosensitive objects with less than the classically expected amount of light being absorbed or scattered by the object. With the most promising system, we obtained high-resolution (10 \mu m), one-dimensional profiles of a variety of objects (human hair, glass and metal wires, cloth fibers), by raster scanning each object through the system. We discuss possible applications and the present and future limits for interaction-free imaging.Comment: 10 pages, 6 encapsulated Postscript figure files, accepted for publication in Physical Review

    Examining the causes of rarity for the Odonata of Illinois

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    Odonata (dragonflies and damselflies) play an important role in habitat management and conservation, but our understanding of the causes of commonness versus rarity in this group is limited. In this study we examined the causes of rarity for the Odonata of Illinois. Using S-ratings for conservation status and published habitat classifications for Illinois odonates, we investigated whether habitat type (lotic versus lentic) or habitat specificity (whether they were limited to a specific type of aquatic habitat) was related to commonness. We found that lotic species and habitat specialists were more likely to be rare than lentic and generalist species. More information, however, is needed on the distributions and natural histories of Illinois odonates if we are to more fully understand the causes of rarity in this important group

    X-Ray Emission from M32: X-Ray Binaries or a micro-AGN?

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    We have analysed archival {\it ROSAT} PSPC data for M32 in order to study the x-ray emission from this nearest elliptical galaxy. We fit spectra from three long exposures with Raymond-Smith, thermal bremsstrahlung, and power-law models. All models give excellent fits. The thermal fits have kT≈\approx4 keV, the Raymond-Smith iron abundance is 0.4−0.3+0.70.4^{+0.7}_{-0.3} Solar, the power-law fit has α\alpha=1.6±\pm0.1, and all fits have NHN_H consistent with the Galactic column. The source is centered on M32 to an accuracy of 9â€Čâ€Č'', and unresolved at 27â€Čâ€Č'' FWHM (∌\sim90 pc). M32 is x-ray variable by a factor of 3--5 on timescales of a decade down to minutes, with evidence for a possible period of ∌\sim1.3 days. There are two plausible interpretations for these results: 1) Emission due to low-mass x-ray binaries; 2) Emission due to accretion onto a massive central black hole. Both of these possibilities are supported by arguments based on previous studies of M32 and other old stellar systems; the {\it ROSAT} PSPC data do not allow us to unambiguously choose between them. Observations with the {\it ROSAT} HRI and with {\it ASCA} are required to determine which of these two very different physical models is correct.Comment: 9 pages, 5 PostScript figures, uses AASTeX style files, Accepted for publication in Astrophysical Journal Letter
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