526 research outputs found
Barriers to student engagement in clubs and societies: a social capital perspective
In 2018/19, John Moores Studentsâ Union embarked on a âground clearingâ exercise to determine the barriers students face when engaging, or trying to engage, with a student-led sports club or society. An online survey to students revealed several barriers: difficulty in âfitting inâ, costs, time, geography, and communication. This paper reflects on the outcomes of the survey and offers an interpretive lens based on the ideas of social capital, as espoused by Pierre Bourdieu and Robert D. Putnam
Topological Entanglement of Polymers and Chern-Simons Field Theory
In recent times some interesting field theoretical descriptions of the
statistical mechanics of entangling polymers have been proposed by various
authors. In these approaches, a single test polymer fluctuating in a background
of static polymers or in a lattice of obstacles is considered. The extension to
the case in which the configurations of two or more polymers become non-static
is not straightforward unless their trajectories are severely constrained. In
this paper we present another approach, based on Chern--Simons field theory,
which is able to describe the topological entanglements of two fluctuating
polymers in terms of gauge fields and second quantized replica fields.Comment: 16 pages, corrected some typos, added two new reference
Entangled Polymer Rings in 2D and Confinement
The statistical mechanics of polymer loops entangled in the two-dimensional
array of randomly distributed obstacles of infinite length is discussed. The
area of the loop projected to the plane perpendicular to the obstacles is used
as a collective variable in order to re-express a (mean field) effective theory
for the polymer conformation. It is explicitly shown that the loop undergoes a
collapse transition to a randomly branched polymer with .Comment: 17 pages of Latex, 1 ps figure now available upon request, accepted
for J.Phys.A:Math.Ge
Web-based communication tools in a European research project: the example of the TRACE project
The multi-disciplinary and international nature of large European projects requires powerful managerial and communicative tools to ensure the transmission of information to the end-users. One such project is TRACE entitled âTracing Food Commodities in Europeâ. One of its objectives is to provide a communication system dedicated to be the central source of information on food authenticity and traceability in Europe. This paper explores the web tools used and communication vehicles offered to scientists involved in the TRACE project to communicate internally as well as to the public. Two main tools have been built: an Intranet and a public website. The TRACE website can be accessed at http://www.trace.eu.org. A particular emphasis was placed on the efficiency, the relevance and the accessibility of the information, the publicity of the website as well as the use of the collaborative utilities. The rationale of web space design as well as integration of proprietary software solutions are presented. Perspectives on the using of web tools in the research projects are discussed
Dysregulation of Glucagon Secretion by Hyperglycemia-Induced Sodium-Dependent Reduction of ATP Production
© 2018 The Author(s). Published by Elsevier Inc.Diabetes is a bihormonal disorder resulting from combined insulin and glucagon secretion defects. Mice lacking fumarase (Fh1) in their ÎČ cells (Fh1ÎČKO mice) develop progressive hyperglycemia and dysregulated glucagon secretion similar to that seen in diabetic patients (too much at high glucose and too little at low glucose). The glucagon secretion defects are corrected by low concentrations of tolbutamide and prevented by the sodium-glucose transport (SGLT) inhibitor phlorizin. These data link hyperglycemia, intracellular Na+ accumulation, and acidification to impaired mitochondrial metabolism, reduced ATP production, and dysregulated glucagon secretion. Protein succination, reflecting reduced activity of fumarase, is observed in α cells from hyperglycemic Fh1ÎČKO and ÎČ-V59M gain-of-function KATP channel mice, diabetic Goto-Kakizaki rats, and patients with type 2 diabetes. Succination is also observed in renal tubular cells and cardiomyocytes from hyperglycemic Fh1ÎČKO mice, suggesting that the model can be extended to other SGLT-expressing cells and may explain part of the spectrum of diabetic complications.Peer reviewe
Critical exponents for random knots
The size of a zero thickness (no excluded volume) polymer ring is shown to
scale with chain length in the same way as the size of the excluded volume
(self-avoiding) linear polymer, as , where . The
consequences of that fact are examined, including sizes of trivial and
non-trivial knots.Comment: 4 pages, 0 figure
Microphase separation in cross-linked polymer blends: Efficient replica RPA post-processing of simulation data for homopolymer networks
We investigate the behaviour of randomly cross-linked (co)polymer blends
using a combination of replica theory and large-scale molecular dynamics
simulations. In particular, we derive the analogue of the random phase
approximation for systems with quenched disorder and show how the required
correlation functions can be calculated efficiently. By post-processing
simulation data for homopolymer networks we are able to describe neutron
scattering measurements in heterogeneous systems without resorting to
microscopic detail and otherwise unphysical assumptions. We obtain structure
function data which illustrate the expected microphase separation and contain
system-specific information relating to the intrinsic length scales of our
networks.Comment: 8 pages, 5 figure
Understanding the distribution of marine megafauna in the English channel region: identifying key habitats for conservation within the busiest seaway on earth.
Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from Public Library of Science via the DOI in this record.The temperate waters of the North-Eastern Atlantic have a long history of maritime resource richness and, as a result, the European Union is endeavouring to maintain regional productivity and biodiversity. At the intersection of these aims lies potential conflict, signalling the need for integrated, cross-border management approaches. This paper focuses on the marine megafauna of the region. This guild of consumers was formerly abundant, but is now depleted and protected under various national and international legislative structures. We present a meta-analysis of available megafauna datasets using presence-only distribution models to characterise suitable habitat and identify spatially-important regions within the English Channel and southern bight of the North Sea. The integration of studies from dedicated and opportunistic observer programmes in the United Kingdom and France provide a valuable perspective on the spatial and seasonal distribution of various taxonomic groups, including large pelagic fishes and sharks, marine mammals, seabirds and marine turtles. The Western English Channel emerged as a hotspot of biodiversity for megafauna, while species richness was low in the Eastern English Channel. Spatial conservation planning is complicated by the highly mobile nature of marine megafauna, however they are important components of the marine environment and understanding their distribution is a first crucial step toward their inclusion into marine ecosystem management.The INTERREG IV A France (Channel) â England cross-border European cooperation programme, co-financed by the European Regional Development Fund as part of the CHannel integrated Approach for marine Resource Management (CHARM) Phase III project provided funding for the meta-analysis presented in this manuscript through EU postdoctoral fellowships to C. McClellan and S. Patrick. R. Deaville provided the UK cetacean strandings data, which together with the marine turtle data was co-funded by the UK Department for Environment, Food and Rural Affairs (Defra) and by the devolved governments in Scotland and Wales. G. Bradbury and J. Darke provided data from the UK's Wildfowl and Wetlands Trust, which was funded by the Department of Energy and Climate Change. T. Dunn provided the Joint Cetacean Database and the European Seabirds at Sea data. P.S. Hammond provided the SCANS and SCANS-II data funded by EU LIFE Nature projects LIFE 92-2/UK/027 and LIFE04NAT/GB/000245, respectively. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
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Preliminary results of the APAC spills working group
The Spills Working Group is one of 6 working groups under the DOE-DP Accident Phenomenology and Consequence (APAC) methodology evaluation program. Objectives are to assess methodologies available in this area, evaluate their adequacy for accident analysis at DOE facilities, identify development needs, and define standard practices to be followed in the analyses supporting facility safety basis documentation. The group focused on methodologies for estimating 4 types of spill source terms: liquid chemical spills and evaporation, pressurized liquid/gas releases, solid spills and resuspension/sublimation, and resuspension of particulate matter from liquid spills. Computer models were identified with capabilities for quantifying release rates or released amounts from spills, and a set of sample test problems was established for evaluating a specific model for some common or probable accident release scenarios. The group agreed on a set of recommended computer codes which are classified according to spill type and hazard category. Code results for a given problem varied by up to an order of magnitude; this is attributed to differences in how the physics and thermodynamics of the problems were treated by the models
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