125 research outputs found

    CASH CROPS CASE STUDIES: Doas the World Bank inhibit Smallholder Cash Cropping? The Case of Malawi

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    Summary This article argues that it is important to differentiate between high value export crops traditionally grown in the estate sector and other crops more often associated with the smallholder sector, in terms of their economic and agricultural characteristics. High value export crops require that a specific set of input services be provided if they are to be successfully grown by smallholders. Typical rural development programmes in Africa have not provided these inputs and have locked smallholders into the production of food crops and lower value export crops which have been historically associated with the smallholder sector, with important consequences for equity and growth. Resumé La Banque Mondiale présente?t?elle un Handicap pour la Production à l'Exportation dans les Petites Exploitations? Le Cas du Malawi Cet article insiste sur le fait qu'il est important de faire la difference, suivant leurs caractéristiques économiques et agricoles, entre les produits à l'exportation et de valeur élevée, traditionellement cultivés dans le secteur des grandes exploitations, et la production associée plus généralement avec les petites exploitations. Les produits agricoles de valeur élevée, destinés à l'exportation demandent la mise en oeuvre d'un nombre spécifique de services afin d'obtenir des résultats satisfaisants lorsque la production est assurée par de petites exploitations. Les programmes typiques de développement rural en Afrique n'ont pas offert la garantie de ces investissements et ont limite les petits exploitants à la production de produits agricoles de première nécessité, traditionellement associés avec le secteur des petites exploitations; ceci a eu des consé quences importances en ce qui concerne l'équité et la croissance. Resumen ¿Inhibe el banco mundial los cultivos comerciales? El caso de Malawi Este artículo destaca la importancia de distinguir los cultivos de exportación de alto valor producidos tradicionalmente en el sector de haciendas de aquellos originados más frecuentemente en el de pequeñas granjas, en términos de sus características agrícolas y económicas. Si se pretende que los primeros sean producidos exitosamente por pequeños agricultores, debe proporcionarse a éstos el conjunto de servicios específicos requeridos. En Africa, los típicos programas de desarrollo rural no proporcionaron estos servicios y encerraron a los pequeños agricultores en la producción de alimentos y de cultivos de exportación de bajo valor, históricamente asociados al sector de pequeños productores, con serias consecuencias para la equidad y el crecimiento

    Differential Muon Tomography to Continuously Monitor Changes in the Composition of Subsurface Fluids

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    Muon tomography has been used to seek hidden chambers in Egyptian pyramids and image subsurface features in volcanoes. It seemed likely that it could be used to image injected, supercritical carbon dioxide as it is emplaced in porous geological structures being used for carbon sequestration, and also to check on subsequent leakage. It should work equally well in any other application where there are two fluids of different densities, such as water and oil, or carbon dioxide and heavy oil in oil reservoirs. Continuous monitoring of movement of oil and/or flood fluid during enhanced oil recovery activities for managing injection is important for economic reasons. Checking on leakage for geological carbon storage is essential both for safety and for economic purposes. Current technology (for example, repeat 3D seismic surveys) is expensive and episodic. Muons are generated by high- energy cosmic rays resulting from supernova explosions, and interact with gas molecules in the atmosphere. This innovation has produced a theoretical model of muon attenuation in the thickness of rock above and within a typical sandstone reservoir at a depth of between 1.00 and 1.25 km. Because this first simulation was focused on carbon sequestration, the innovators chose depths sufficient for the pressure there to ensure that the carbon dioxide would be supercritical. This innovation demonstrates for the first time the feasibility of using the natural cosmic-ray muon flux to generate continuous tomographic images of carbon dioxide in a storage site. The muon flux is attenuated to an extent dependent on, amongst other things, the density of the materials through which it passes. The density of supercritical carbon dioxide is only three quarters that of the brine in the reservoir that it displaces. The first realistic simulations indicate that changes as small as 0.4% in the storage site bulk density could be detected (equivalent to 7% of the porosity, in this specific case). The initial muon flux is effectively constant at the surface of the Earth. Sensitivity of the method would be decreased with increasing depth. However, sensitivity can be improved by emplacing a greater array of particle detectors at the base of the reservoir

    CYGNUS

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    Directional information in the direct dark matter searches is believed to be able providing a clear discovery of the galactic WIMP dark matter, together with a further potential to investigate the properties of the dark matter. CYGNUS is a concept to detect the galactic WIMP dark matter particles with directionality. In this paper, physics motivation and technological R&D status will be reviewedThis work was supported by the Japanese Ministry of Education, Culture, Sports, Science and Technology, Grant-in-Aid for Scientic Research, ICRR Joint-Usage, JSPS KAKENHI Grant Number, 16H02189, 19H05802, 19H05806, 26104001, 26104005, and JSPS Bilateral Collaborations (Joint Research Projects and Seminars) program. This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No 818744)

    Risk Assessment of Impacts of Climate Change for Key Marine Species in South Eastern Australia. Part 2: species profiles

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    [Extract] Blacklip and greenlip abalone form the basis of valuable fisheries in Tasmania, Victoria, South Australia and New South Wales (Figure 1.1). The Tasmanian abalone fishery is the largest wild abalone fishery in the world, producing more than 25% of the global catch (Miller et al. 2009). In 2008, the fishery had a gross landed value of $ 90 million. Blacklip abalone (BA), Haliotis rubra, is the predominant species harvested in Tasmania with 2461 t landed in 2008, compared to only 122 t of greenlip abalone (GA), H. laevigata (Tarbath and Gardner 2009). Since 2003, the BA fishery has been divided into five zones: Eastern, Western, Northern, Bass Strait, and Central West (Tarbath and Gardner 2009). The GA fishery is restricted to the north of the state and is managed by regions and separately from the BA fishery. In Victoria, approximately 1,200 t was landed in 2007/08, however, the current TAC is 774 t (2010/11). Catches are dominated by BA (96%) and the fishery is structured into three zones: Western, Central and Eastern. The South Australian fishery harvests approximately 880 t of abalone each year, about 60% of this is BA with the remainder comprising GA. Like Victoria, the South Australian fishery is divided into the Southern, Central and Western zones. Current annual catches in NSW were less than 75 t in 2009/10 and consist exclusively of BA. The commercial fisheries are assessed on a variable combination of commercial catch, effort and size-composition data, fishery-independent surveys and length-structured models. In Tasmania, 105,500 abalone were taken by recreational fishers in 2006/07, weighing an estimated 49 t. The number of recreational licenses has tripled since 1995, with 12,500 recreational diving licenses issued in 2007/08 (Lyle 2008). Recreational catches in SA are small, probably less than 1% of the TACC (Jones, 2009)

    Risk Assessment of Impacts of Climate Change for Key Marine Species in South Eastern Australia. Part 2: species profiles

    Get PDF
    [Extract] Blacklip and greenlip abalone form the basis of valuable fisheries in Tasmania, Victoria, South Australia and New South Wales (Figure 1.1). The Tasmanian abalone fishery is the largest wild abalone fishery in the world, producing more than 25% of the global catch (Miller et al. 2009). In 2008, the fishery had a gross landed value of $ 90 million. Blacklip abalone (BA), Haliotis rubra, is the predominant species harvested in Tasmania with 2461 t landed in 2008, compared to only 122 t of greenlip abalone (GA), H. laevigata (Tarbath and Gardner 2009). Since 2003, the BA fishery has been divided into five zones: Eastern, Western, Northern, Bass Strait, and Central West (Tarbath and Gardner 2009). The GA fishery is restricted to the north of the state and is managed by regions and separately from the BA fishery. In Victoria, approximately 1,200 t was landed in 2007/08, however, the current TAC is 774 t (2010/11). Catches are dominated by BA (96%) and the fishery is structured into three zones: Western, Central and Eastern. The South Australian fishery harvests approximately 880 t of abalone each year, about 60% of this is BA with the remainder comprising GA. Like Victoria, the South Australian fishery is divided into the Southern, Central and Western zones. Current annual catches in NSW were less than 75 t in 2009/10 and consist exclusively of BA. The commercial fisheries are assessed on a variable combination of commercial catch, effort and size-composition data, fishery-independent surveys and length-structured models. In Tasmania, 105,500 abalone were taken by recreational fishers in 2006/07, weighing an estimated 49 t. The number of recreational licenses has tripled since 1995, with 12,500 recreational diving licenses issued in 2007/08 (Lyle 2008). Recreational catches in SA are small, probably less than 1% of the TACC (Jones, 2009)

    Eye Movements Affect Postural Control in Young and Older Females

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    Visual information is used for postural stabilization in humans. However, little is known about how eye movements prevalent in everyday life interact with the postural control system in older individuals. Therefore, the present study assessed the effects of stationary gaze fixations, smooth pursuits, and saccadic eye movements, with combinations of absent, fixed and oscillating large-field visual backgrounds to generate different forms of retinal flow, on postural control in healthy young and older females. Participants were presented with computer generated visual stimuli, whilst postural sway and gaze fixations were simultaneously assessed with a force platform and eye tracking equipment, respectively. The results showed that fixed backgrounds and stationary gaze fixations attenuated postural sway. In contrast, oscillating backgrounds and smooth pursuits increased postural sway. There were no differences regarding saccades. There were also no differences in postural sway or gaze errors between age groups in any visual condition. The stabilizing effect of the fixed visual stimuli show how retinal flow and extraocular factors guide postural adjustments. The destabilizing effect of oscillating visual backgrounds and smooth pursuits may be related to more challenging conditions for determining body shifts from retinal flow, and more complex extraocular signals, respectively. Because the older participants matched the young group's performance in all conditions, decreases of posture and gaze control during stance may not be a direct consequence of healthy aging. Further research examining extraocular and retinal mechanisms of balance control and the effects of eye movements, during locomotion, is needed to better inform fall prevention interventions

    US Cosmic Visions: New Ideas in Dark Matter 2017: Community Report

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    This white paper summarizes the workshop "U.S. Cosmic Visions: New Ideas in Dark Matter" held at University of Maryland on March 23-25, 2017.Comment: 102 pages + reference

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

    LIME -- a gas TPC prototype for directional Dark Matter search for the CYGNO experiment

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    The CYGNO experiment aims at the development of a large gaseous TPC with GEM-based amplification and an optical readout by means of PMTs and scientific CMOS cameras for 3D tracking down to O(keV) energies, for the directional detection of rare events such as low mass Dark Matter and solar neutrino interactions. The largest prototype built so far towards the realisation of the CYGNO experiment demonstrator is the 50 L active volume LIME, with 4 PMTs and a single sCMOS imaging a 33×\times33 cm\textsuperscript{2} area for 50 cm drift, that has been installed in underground Laboratori Nazionali del Gran Sasso in February 2022. We will illustrate LIME performances as evaluated overground in Laboratori Nazionali di Frascati by means of radioactive X-ray sources, and in particular the detector stability, energy response and energy resolution. We will discuss the MC simulation developed to reproduce the detector response and show the comparison with actual data. We will furthermore examine the background simulation worked out for LIME underground data taking and illustrate the foreseen expected measurement and results in terms of natural and materials intrinsic radioactivity characterisation and measurement of the LNGS underground natural neutron flux. The results that will be obtained by underground LIME installation will be paramount in the optimisation of the CYGNO demonstrator, since this is foreseen to be composed by multiple modules with the same LIME dimensions and characteristics
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