377 research outputs found

    Assessing Scotland's Progress on the Environmental Agenda

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    For good reasons the environment has a high political profile in Scotland. This report is concerned with three important components of the environmental agenda and the way in which they are being taken forward by the responsible authorities in Scotland. The delivery of environmental outcomes on agricultural land by means of a range of current policies, including agri-environment schemes, cross-compliance conditions on direct payments to farmers and implementation of the EU Water Framework Directive.The selection and management of a new network of Marine Protected Areas.Policy measures designed to reduce greenhouse gas emissions and to mitigate climate change.Each of these topics is addressed individually in three separate chapters, aiming to identify some of the leading questions and the policy responses that have been adopted. The progress that is being made in meeting the objectives and aspirations set out in legislation and other key policy documents is then considered. Some of the objectives under review are determined entirely by the Government and by more local authorities in Scotland. Others arise primarily from obligations under EU legislation

    An analytical model for bore-driven run-up

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    We use a hodograph transformation and a boundary integral method to derive a new analytical solution to the shallow-water equations describing bore-generated run-up on a plane beach. This analytical solution differs from the classical Shen-Meyer runup solution in giving significantly deeper and less asymmetric swash flows, and also by predicting the inception of a secondary bore in both the backwash and the uprush in long surf. We suggest that this solution provides a significantly improved model for flows including swash events and the run-up following breaking tsunamis

    Exploiting molecular dynamics in Nested Sampling simulations of small peptides

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    Nested Sampling (NS) is a parameter space sampling algorithm which can be used for sampling the equilibrium thermodynamics of atomistic systems. NS has previously been used to explore the potential energy surface of a coarse-grained protein model and has significantly outperformed parallel tempering when calculating heat capacity curves of Lennard-Jones clusters. The original NS algorithm uses Monte Carlo (MC) moves; however, a variant, Galilean NS, has recently been introduced which allows NS to be incorporated into a molecular dynamics framework, so NS can be used for systems which lack efficient prescribed MC moves. In this work we demonstrate the applicability of Galilean NS to atomistic systems. We present an implementation of Galilean NS using the Amber molecular dynamics package and demonstrate its viability by sampling alanine dipeptide, both in vacuo and implicit solvent. Unlike previous studies of this system, we present the heat capacity curves of alanine dipeptide, whose calculation provides a stringent test for sampling algorithms. We also compare our results with those calculated using replica exchange molecular dynamics (REMD) and find good agreement. We show the computational effort required for accurate heat capacity estimation for small peptides. We also calculate the alanine dipeptide Ramachandran free energy surface for a range of temperatures and use it to compare the results using the latest Amber force field with previous theoretical and experimental results

    STRAND: A Model for Longshore Sediment Transport in the Swash Zone

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    In this paper we report on the development and performance of an engineering model, STRAND which has the aim of predicting longshore movement of coarse sediment above the still water line of steep beaches. The model assumes that this transport is driven by swash run-up at the edge of an unsaturated inner surfzone and uses Nielsen's (1992) formulation for sediment transport rate. The hydrodynamic sub-model is shown to agree well with field measurements of swash run-up and swash period. We argue that consideration of interactions between subsequent swash events implies that a monotonic relationship between transport rate and incident wave period is inappropriate. Bulk longshore transport rates are shown to compare reasonably with previous estimates from field studies in the UK and accounts for up to 50% of the net longshore flux. Agreement of this simplified model with one of the best available laboratory data sets, Kamphuis (1991a,b), is very good indeed. However, new laboratory and field data are required before stronger conclusions can be drawn

    Measurement and modeling of the influence of grain size and pressure gradients on swash zone sediment transport

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    The paper examines the dependency between sediment transport rate, q, and grain size, D, (i.e. q∝Dp) in the swash zone. Experiments were performed using a dam break flow as a proxy for swash overtopping on a mobile sediment beach. The magnitude and nature of the dependency (i.e. p value) is inferred for different flow parameters; the initial dam depth (or initial bore height), do, the integrated depth averaged velocity, ∫u3 dt, and against the predicted transport, qp using the Meyer-Peter Muller (MPM) transport model. Experiments were performed over both upward sloping beds and a horizontal bed. The data show that negative dependencies (p0) are obtained for ∫u3 dt. This indicates that a given do and qp transport less sediment as grain size increases, whereas transport increases with grain size for a given ∫u3 dt. The p value is expected to be narrow ranged, 0.5≤ p≤-0.5. A discernible difference observed between the measured and predicted transport on horizontal and sloping beds suggests different modes of transport. The incorporation of a pressure gradient correction, dp/dx, using the surface water slope (i.e. piezometric head), in the transport calculation greatly improved the transport predictions on the horizontal bed, where dp/dx is positive. On average, the incorporation of a pressure gradient term into the MPM formulation reduces qp in the uprush by 4% (fine sand) to 18% (coarse sand) and increases qp over a horizontal bed by 1% (fine sand) to two orders of magnitude (coarse sand). The measured transport for fine and coarse sand are better predicted using MPM and MPM+dp/dx respectively. Poor predictions are obtained using Nielsen (2002) because the pressure gradient in the uprush is of opposite sign to that inferred from velocity data in that paper. It is suggested that future swash sediment transport models should incorporate the grain size effect, partly through the pressure gradient, although the dp/dx influence is small for fine sands because of the grain size scaling contained in the stress term

    Field measurements of beach-dune dynamic profiles to assess erosion hazard on the coast of NSW, Australia

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    The coast of New South Wales (NSW), Australia is about 2000 km long and consists of 721 sandy beaches (68%), rock coastline (32%), and more than 185 estuaries. It is most populated in Australia and one of the NSW greatest assets with significant economic, social and environmental values. The NSW coast has epsodically been ravaged by severe storms together with large ocean waves and high water levels, resulting in severe dune-beach erosion/recession, damaging coastal infrastructure and properties and degrading coastal ecosystems. With potential changes to storm-wave climate and rising sea level, coastal erosion hazards on the NSW coast are likely to worsen in the future. This study was undertaken to collect essential field data on beachdune profiles and sediment grain-size distributions over more than 200 sandy beaches to assess NSW coastal erosion hazard. For each of the selected beaches, three beach-dune profiles of shore-normal transects at 50m apart were surveyed by RTK-GPS, and three sediment samples only on the first transect line were also colleced from the dune, dry beach/berm and swash zone by using a simple hand grabbing method. A sediment grain size analyzer, Malvern Mastersizer 2000E, was used to obtain sediment grain size distributions. It is found that the 618 sediment samples analysed consist of fine sand (10%), medium sand (82%) and coarse sand (8%), and that the dune sand d50 correlates well with the dry-beach sand d50 and is about 8% smaller, but less well correlates with the swash sand d50 and is about 15% smaller. The beach orientation was estimated from the direction of the shore-normal transect lines and generally ranges from 90o to 150o. The beaches surveyed are found to have erosion problems when they weredirectly exposed to predominant waves in the south-east direction and also when the dune toe elevations were lower than 3~3.5m (AHD). A conceptual model is also developed to assess likelihood storm erosion of a beach-dune system

    Case Study - United Kingdom, Sustainable Agriculture and Soil Conservation (SoCo Project)

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    This Technical Note 'Case Study ¿ United Kingdom' is part of a series of case studies within the ¿Sustainable Agriculture and Soil Conservation¿ (SoCo) project. Ten case studies were carried out in Belgium, Bulgaria, the Czech Republic, Denmark, France, Germany, Greece, Italy, Spain and the United Kingdom between spring and summer 2008. The selection of case study areas was designed to capture differences in soil degradation processes, soil types, climatic conditions, farm structures and farming practices, institutional settings and policy priorities. A harmonised methodological approach was pursued in order to gather insights from a range of contrasting conditions over a geographically diverse area. The case studies were carried out by local experts to reflect the specificities of the selected case studies.JRC.DDG.J.5-Agriculture and Life Sciences in the Econom

    The Effect of Self-Focused Attention and Mood on Appearance Dissatisfaction after Mirror-Gazing: An Experimental Study

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    Background and objectives: Self-focused attention is hypothesized to be a maintenance factor in body dysmorphic disorder (BDD). The aim of this study was to use an experimental paradigm to test this hypothesis by studying the effect of self-focused attention during mirror-gazing on appearance dissatisfaction. Methods: An experimental group design was used, in which 173 women were randomly allocated to one of three conditions before mirror-gazing for 2 min: (a) external focus of attention, (b) self-focus of attention, and (c) self-focus of attention with a negative mood induction. Results: After mirror-gazing, participants across all groups rated themselves as being more dissatisfied with their appearance. In both the self-focus conditions, there was an increase in sadness from pre to post mirror gazing, and there was a significant difference in focus of attention for participants in the self-focused, mood-induced group from pre to post manipulation, suggesting mood induction had more of an effect than focus of attention. Limitations: (1) there was no condition involving an external focus with a negative mood induction, and (2) due to the level of information provided to patients on the nature of the task, we cannot rule out demand characteristics as an influencing factor on our results. Conclusions: Self-focused attention during mirror-gazing may act indirectly to increase appearance dissatisfaction via the effect of negative mood. Further studies are required to establish the relative contribution of self-focused attention and negative mood to increases in appearance dissatisfaction as a function of mirror-gazing
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