143 research outputs found

    Improving learning outcomes within a developing maritime nation lacking practical resources through the introduction of classroom technology : a case study at a South African University of Technology

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    This study primarily explores whether or not the use of emerging technologies can be used to counter a lack of available resources in developing countries. The research takes the form of a case study conducted over three successive semesters at a South African University of Technology maritime campus, with the subjects being the Marine Engineering students at a senior level. The study makes extensive use of concept mapping to introduce digital syllabi according to scaffold learning principles, and thereafter to implement a range of selected learning methods based on prominent learning theories to address the needs of the students, as identified by the surveyed data received. Throughout the eighteen-month classroom case study, an action research method was employed to sequentially evaluate the outcomes at each phase, and amend the devised CBT program in line with addressing the research question posed. It was the intention to ascertain if any noticeable changes were evident with regards to the development of critical thinking skills on the part of the students, which would indicate a higher level of learning. The development of critical thinking skills is in line with the desire of the South African government to develop of a skills-based economy for the country, away from an historical past whereby the following of a system was often viewed above the need for critical thinking

    Promoting inclusion oral-health:social interventions to reduce oral health inequities

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    The aim of this collection of papers is to provide the reader with a cogent understanding of the role of evidence in the development of social or community-based interventions to promote inclusion oral-health and reduce oral health, health, and psychosocial inequities. In addition, this material will include various methods used for their implementation and evaluation. At the outset, the reader will be offered a working definition of inclusion oral-health, which will be modelled on the work of Luchenski et al. [1]. The interventions described are theoretically underpinned by a pluralistic definition of evidence-based practice [2] and the radical discourse of health promotion as postulated by Laverack and Labonte [3] and others [4,5]. This Special Issue will consist of eight papers, including an introduction. The first three papers will examine the various sources of evidence used to transform top-down into bottom-up community-based interventions for people experiencing homelessness; people in custody and for families residing in areas of high social deprivation. The final four papers will report on the implementation and evaluation of social or community-based interventions. This collection of research papers will highlight the importance of focusing on prevention and the adoption of a common risk factor agenda to tackle oral health, health and psychosocial inequities felt by those most excluded in our societies

    Optimization and Mathematical Modelling for Path Planning of Co-operative Intra-logistics Automated Vehicles

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    Small indoor Autonomous Vehicles have revolutionized the operation of pick-pack-and-ship warehouses. The challenges for path planning and co-operation in this domain stem from uncontrolled environments including workspaces shared with humans and human-operated vehicles. Solutions are needed which scale up to the largest existing sites with thousands of vehicles and beyond. These challenges might be familiar to anyone modelling road traffic control with the introduction of Autonomous Vehicles, but key differences in the level of decision autonomy lead to different approaches to conflict-resolution. This thesis proposes a decomposition of site-wide conflict-free motion planning into individual shortest paths though a roadmap representing the free space across the site, zone-based speed optimization to resolve conflicts in the vicinity of one intersection and individual path optimization for local obstacles. In numerical tests the individual path optimization based on clothoid basis functions created paths traversable by different vehicle configurations (steering rate limit, lateral acceleration limit and wheelbase) only by choosing an appropriate maximum longitudinal speed. Using two clothoid segments per convex region was sufficient to reach any goal, and the problem could be solved reliably and quickly with sequential quadratic programming due to the approximate graph method used to determine a good sequence of obstacle-free regions to the local goal. A design for zone-based intersection management, obtained by minimizing a linear objective subject to quadratic constraints was refined by the addition of a messaging interface compatible with the path adaptations based on clothoids. A new approximation of the differential constraints was evaluated in a multi-agent simulation of an elementary intersection layout. The proposed FIFO ordering heuristic converted the problem into a linear program. Interior point methods either found a solution quickly or showed that the problem was infeasible, unlike a quadratic constraint formulation with ordering flexibility. Subsequent tests on more complex multi-lane intersection geometries showed the quadratic constraint formulation converged to significantly better solutions than FIFO at the cost of longer and unpredictable search time. Both effects were magnified as the number of vehicles increased. To properly address site-wide conflict-free motion planning, it is essential that the local solutions are compatible with each other at the zone boundaries. The intersection management design was refined with new boundary constraints to ensure compatibility and smooth transitions without the need for a backup system. In numerical tests it was found that the additional boundary constraints were sufficient to ensure smooth transitions on an idealized map including two intersections

    VAT revenue elasticities: an analytical approach. ESRI WP596, September 2018

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    In this paper we construct analytical estimates of the elasticity of VAT revenue with respect to underlying gross income and expenditure for the household sector in Ireland. The responsiveness of VAT revenue to changes in gross income steadily increased up to the late 2000s as marginal income tax rates fell. The introduction of the income levy and the doubling of the health levy resulted in a reduction in the VAT elasticity, as higher income tax rates also reduced the disposable income available for expenditure. This spill-over effect highlights the importance of judging the broader implications of tax policy. It also suggests that policymakers during any subsequent fiscal crisis should be cautious when choosing the composition of tax adjustments, as there is a clear trade-off to be made. The VAT revenue elasticity is lower for Ireland than estimates for the UK, New Zealand and Australia, possibly reflecting the greater progressivity of the Irish income tax system compared to other OECD countries

    Buried alive: Aquatic plants survive in ‘ghost ponds’ under agricultural fields

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    The widespread loss of wetlands due to agricultural intensification has been highlighted as a major threat to aquatic biodiversity. However, all is not lost as we reveal that the propagules of some aquatic species could survive burial under agricultural fields in the sediments of ‘ghost ponds’ - ponds in-filled during agricultural land consolidation. Our experiments showed at least eight aquatic macrophyte species to germinate from seeds and oospores, following 50–150 years of dormancy in the sediments of ghost ponds. This represents a significant proportion of the expected macrophyte diversity for local farmland ponds, which typically support between 6 and 14 macrophyte species. The rapid (< 6 months) re-colonisation of resurrected ghost ponds by a diverse aquatic vegetation similarly suggests a strong seed-bank influence. Ghost ponds represent abundant, dormant time capsules for aquatic species in agricultural landscapes around the globe, affording opportunities for enhancing landscape-scale aquatic biodiversity and connectivity. While reports of biodiversity loss through agricultural intensification dominate conservation narratives, our study offers a rare positive message, demonstrating that aquatic organisms survive prolonged burial under intensively managed agricultural fields. We urge conservationists and policy makers to consider utilizing and restoring these valuable resources in biodiversity conservation schemes and in agri-environmental approaches and policies

    Resurrection and emendation of the Hypoxylaceae, recognised from a multigene phylogeny of the Xylariales

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    A multigene phylogeny was constructed, including a significant number of representative species of the main lineages in the Xylariaceae and four DNA loci the internal transcribed spacer region (ITS), the large subunit (LSU) of the nuclear rDNA, the second largest subunit of the RNA polymerase II (RPB2), and beta-tubulin (TUB2). Specimens were selected based on more than a decade of intensive morphological and chemotaxonomic work, and cautious taxon sampling was performed to cover the major lineages of the Xylariaceae; however, with emphasis on hypoxyloid species. The comprehensive phylogenetic analysis revealed a clear-cut segregation of the Xylariaceae into several major clades, which was well in accordance with previously established morphological and chemotaxonomic concepts. One of these clades contained Annulohypoxylon, Hypoxylon, Daldinia, and other related genera that have stromatal pigments and a nodulisporium-like anamorph. They are accommodated in the family Hypoxylaceae, which is resurrected and emended. Representatives of genera with a nodulisporium-like anamorph and bipartite stromata, lacking stromatal pigments (i.e. Biscogniauxia, Camillea, and Obolarina) appeared in a clade basal to the xylarioid taxa. As they clustered with Graphostroma platystomum, they are accommodated in the Graphostromataceae. The new genus Jackrogersella with J. multiformis as type species is segregated from Annulohypoxylon. The genus Pyrenopolyporus is resurrected for Hypoxylon polyporus and allied species. The genus Daldinia and its allies Entonaema, Rhopalostroma, Ruwenzoria, and Thamnomyces appeared in two separate subclades, which may warrant further splitting of Daldinia in the future, and even Hypoxylon was divided in several clades. However, more species of these genera need to be studied before a conclusive taxonomic rearrangement can be envisaged. Epitypes were designated for several important species in which living cultures and molecular data are available, in order to stabilise the taxonomy of the Xylariales.Fil: Wendt, Lucile. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; AlemaniaFil: Sir, Esteban Benjamin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Unidad Ejecutora Lillo. Fundación Miguel Lillo. Unidad Ejecutora Lillo; ArgentinaFil: Kuhnert, Eric. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; AlemaniaFil: Heitkämper, Simone. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; AlemaniaFil: Lambert, Christopher. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; AlemaniaFil: Hladki, Adriana I.. Fundación Miguel Lillo. Dirección de Botánica. Instituto de Micologia; ArgentinaFil: Romero, Andrea Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Luangsa-Ard, Janet Jennifer. National Center for Genetic Engineering and Biotechnology; TailandiaFil: Srikitikulchai, Prasert. National Center for Genetic Engineering and Biotechnology; TailandiaFil: Peršoh, Derek. Ruhr-Universität Bochum; AlemaniaFil: Stadler, Marc. Helmholtz-Zentrum für Infektionsforschung GmbH. Department of Microbial Drugs; Alemania. German Centre for Infection Research; Alemani

    Buried alive: Aquatic plants survive in ‘ghost ponds’ under agricultural fields

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    The widespread loss of wetlands due to agricultural intensification has been highlighted as a major threat to aquatic biodiversity. However, all is not lost as we reveal that the propagules of some aquatic species could survive burial under agricultural fields in the sediments of ‘ghost ponds’ - ponds in-filled during agricultural land consolidation. Our experiments showed at least eight aquatic macrophyte species to germinate from seeds and oospores, following 50–150 years of dormancy in the sediments of ghost ponds. This represents a significant proportion of the expected macrophyte diversity for local farmland ponds, which typically support between 6 and 14 macrophyte species. The rapid (< 6 months) re-colonisation of resurrected ghost ponds by a diverse aquatic vegetation similarly suggests a strong seed-bank influence. Ghost ponds represent abundant, dormant time capsules for aquatic species in agricultural landscapes around the globe, affording opportunities for enhancing landscape-scale aquatic biodiversity and connectivity. While reports of biodiversity loss through agricultural intensification dominate conservation narratives, our study offers a rare positive message, demonstrating that aquatic organisms survive prolonged burial under intensively managed agricultural fields. We urge conservationists and policy makers to consider utilizing and restoring these valuable resources in biodiversity conservation schemes and in agri-environmental approaches and policies

    Human neutrophil kinetics: modeling of stable isotope labeling data supports short blood neutrophil half-lives.

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    Human neutrophils have traditionally been thought to have a short half-life in blood; estimates vary from 4-18 hours. This dogma was recently challenged by stable isotope labeling studies with heavy water which yielded estimates in excess of 3 days. To investigate this disparity we generated new stable isotope labeling data in healthy adult subjects using both heavy water (n=4) and deuterium-labeled glucose (n=9), a compound with more rapid labeling kinetics. To interpret results we developed a novel mechanistic model. We applied this model to both previously-published (n=5) and newly-generated data. We initially constrained the ratio of the blood neutrophil pool to the marrow precursor pool (R=0.26, from published values). Analysis of heavy water datasets yielded turnover rates consistent with a short blood half-life, but parameters, particularly marrow transit-time, were poorly-defined. Analysis of glucose-labeling data yielded more precise estimates of half-life, 0.79 ± 0.25 days (19 hours), and marrow transit-time, 5.80 ± 0.42 days. Substitution of this marrow transit-time in the heavy water analysis gave a better-defined blood half-life, 0.77 ± 0.14 days (18.5 hours), close to glucose-derived values. Allowing R to vary yielded a best-fit value, R=0.19. Reanalysis of the previously-published model and data also revealed the origin of their long estimates for neutrophil half-life, an implicit assumption that R is very large, which is physiologically untenable. We conclude that stable isotope labeling in healthy humans is consistent with a blood neutrophil half-life of less than one day

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

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    Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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