905 research outputs found
Research Project as Boundary Object: negotiating the conceptual design of a tool for International Development
This paper reflects on the relationship between who one designs for and what one designs in the unstructured space of designing for political change; in particular, for supporting âInternational Developmentâ with ICT. We look at an interdisciplinary research project with goals and funding, but no clearly defined beneficiary group at start, and how amorphousness contributed to impact. The reported project researched a bridging tool to connect producers with consumers across global contexts and show players in the
supply chain and their circumstances. We explore how both the nature of the research and the toolâs function became contested as work progressed. To tell this tale, we invoke
the idea of boundary objects and the value of tacking back and forth between elastic meanings of the projectâs artefacts and processes. We examine the projectâs role in India, Chile and other arenas to draw out ways that it functioned as a catalyst and how absence of committed design choices acted as an unexpected strength in reaching its goals
Modulated Amplitude Waves in Bose-Einstein Condensates
We analyze spatio-temporal structures in the Gross-Pitaevskii equation to
study the dynamics of quasi-one-dimensional Bose-Einstein condensates (BECs)
with mean-field interactions. A coherent structure ansatz yields a
parametrically forced nonlinear oscillator, to which we apply Lindstedt's
method and multiple-scale perturbation theory to determine the dependence of
the intensity of periodic orbits (``modulated amplitude waves'') on their wave
number. We explore BEC band structure in detail using Hamiltonian perturbation
theory and supporting numerical simulations.Comment: 5 pages, 4 figs, revtex, final form of paper, to appear in PRE
(forgot to include \bibliography command in last update, so this is a
correction of that; the bibliography is hence present again
Genera of diaporthalean coelomycetes associated with leaf spots of tree hosts
Four different genera of diaporthalean coelomycetous fungi associated with leaf spots of tree hosts are morphologically treated and phylogenetically compared based on the DNA sequence data of the large subunit nuclear ribosomal DNA gene (LSU) and the internal transcribed spacers and 5.8S rRNA gene of the nrDNA operon. These include two new Australian genera, namely Auratiopycnidiella, proposed for a leaf spotting fungus occurring on Tristaniopsis laurina in New South Wales, and Disculoides, proposed for two species occurring on leaf spots of Eucalyptus leaves in Victoria. Two new species are described in Aurantiosacculus, a hitherto monotypic genus associated with leaf spots of Eucalyptus in Australia, namely A. acutatus on E. viminalis, and A. eucalyptorum on E. globulus, both occurring in Tasmania. Lastly, an epitype specimen is designated for Erythrogloeum hymenaeae, the type species of the genus Erythrogloeum, and causal agent of a prominent leaf spot disease on Hymenaea courbaril in South America. All four genera are shown to be allied to Diaporthales, although only Aurantiosacculus (Cryphonectriaceae) could be resolved to family level, the rest being incertae sedis
Multistable Solitons in the Cubic-Quintic Discrete Nonlinear Schr\"odinger Equation
We analyze the existence and stability of localized solutions in the
one-dimensional discrete nonlinear Schr\"{o}dinger (DNLS) equation with a
combination of competing self-focusing cubic and defocusing quintic onsite
nonlinearities. We produce a stability diagram for different families of
soliton solutions, that suggests the (co)existence of infinitely many branches
of stable localized solutions. Bifurcations which occur with the increase of
the coupling constant are studied in a numerical form. A variational
approximation is developed for accurate prediction of the most fundamental and
next-order solitons together with their bifurcations. Salient properties of the
model, which distinguish it from the well-known cubic DNLS equation, are the
existence of two different types of symmetric solitons and stable asymmetric
soliton solutions that are found in narrow regions of the parameter space. The
asymmetric solutions appear from and disappear back into the symmetric ones via
loops of forward and backward pitchfork bifurcations.Comment: To appear Physica D. 23 pages, 13 figure
Mutual Events in the Cold Classical Transneptunian Binary System Sila and Nunam
Hubble Space Telescope observations between 2001 and 2010 resolved the binary
components of the Cold Classical transneptunian object (79360) Sila-Nunam
(provisionally designated 1997 CS29). From these observations we have
determined the circular, retrograde mutual orbit of Nunam relative to Sila with
a period of 12.50995 \pm 0.00036 days and a semimajor axis of 2777 \pm 19 km. A
multi-year season of mutual events, in which the two near-equal brightness
bodies alternate in passing in front of one another as seen from Earth, is in
progress right now, and on 2011 Feb. 1 UT, one such event was observed from two
different telescopes. The mutual event season offers a rich opportunity to
learn much more about this barely-resolvable binary system, potentially
including component sizes, colors, shapes, and albedo patterns. The low
eccentricity of the orbit and a photometric lightcurve that appears to coincide
with the orbital period are consistent with a system that is tidally locked and
synchronized, like the Pluto-Charon system. The orbital period and semimajor
axis imply a system mass of (10.84 \pm 0.22) \times 10^18 kg, which can be
combined with a size estimate based on Spitzer and Herschel thermal infrared
observations to infer an average bulk density of 0.72 +0.37 -0.23 g cm^-3,
comparable to the very low bulk densities estimated for small transneptunian
binaries of other dynamical classes.Comment: In press in Icaru
Multistable Solitons in Higher-Dimensional Cubic-Quintic Nonlinear Schroedinger Lattices
We study the existence, stability, and mobility of fundamental discrete
solitons in two- and three-dimensional nonlinear Schroedinger lattices with a
combination of cubic self-focusing and quintic self-defocusing onsite
nonlinearities. Several species of stationary solutions are constructed, and
bifurcations linking their families are investigated using parameter
continuation starting from the anti-continuum limit, and also with the help of
a variational approximation. In particular, a species of hybrid solitons,
intermediate between the site- and bond-centered types of the localized states
(with no counterpart in the 1D model), is analyzed in 2D and 3D lattices. We
also discuss the mobility of multi-dimensional discrete solitons that can be
set in motion by lending them kinetic energy exceeding the appropriately
crafted Peierls-Nabarro barrier; however, they eventually come to a halt, due
to radiation loss.Comment: 12 pages, 17 figure
Manageable creativity
This article notes a perception in mainstream management theory and practice that creativity has shifted from being disruptive or destructive to 'manageable'. This concept of manageable creativity in business is reflected in a similar rhetoric in cultural policy, especially towards the creative industries. The article argues that the idea of 'manageable creativity' can be traced back to a 'heroic' and a 'structural' model of creativity. It is argued that the 'heroic' model of creativity is being subsumed within a 'structural' model which emphasises the systems and infrastructure around individual creativity rather than focusing on raw talent and pure content. Yet this structured approach carries problems of its own, in particular a tendency to overlook the unpredictability of creative processes, people and products. Ironically, it may be that some confusion in our policies towards creativity is inevitable, reflecting the paradoxes and transitions which characterise the creative process
Spectral Properties of the Overlap Dirac Operator in QCD
We discuss the eigenvalue distribution of the overlap Dirac operator in
quenched QCD on lattices of size 8^{4}, 10^{4} and 12^{4} at \beta = 5.85 and
\beta = 6. We distinguish the topological sectors and study the distributions
of the leading non-zero eigenvalues, which are stereographically mapped onto
the imaginary axis. Thus they can be compared to the predictions of random
matrix theory applied to the \epsilon-expansion of chiral perturbation theory.
We find a satisfactory agreement, if the physical volume exceeds about (1.2
fm)^{4}. For the unfolded level spacing distribution we find an accurate
agreement with the random matrix conjecture on all volumes that we considered.Comment: 16 pages, 8 figures, final version published in JHE
Involving older people in a multi-centre randomised trial of a complex intervention in pre-hospital emergency care: implementation of a collaborative model
Background
Health services research is expected to involve service users as active partners in the research process, but few examples report how this has been achieved in practice in trials. We implemented a model to involve service users in a multi-centre randomised controlled trial in pre-hospital emergency care. We used the generic Standard Operating Procedure (SOP) from our Clinical Trials Unit (CTU) as the basis for creating a model to fit the context and population of the SAFER 2 trial.
Methods
In our model, we planned to involve service users at all stages in the trial through decision-making forums at 3 levels: 1) strategic; 2) site (e.g. Wales; London; East Midlands); 3) local. We linked with charities and community groups to recruit people with experience of our study population. We collected notes of meetings alongside other documentary evidence such as attendance records and study documentation to track how we implemented our model.
Results
We involved service users at strategic, site and local level. We also added additional strategic level forums (Task and Finish Groups and Writing Days) where we included service users. Service user involvement varied in frequency and type across meetings, research stages and locations but stabilised and increased as the trial progressed.
Conclusion
Involving service users in the SAFER 2 trial showed how it is feasible and achievable for patients, carers and potential patients sharing the demographic characteristics of our study population to collaborate in a multi-centre trial at the level which suited their health, location, skills and expertise. A standard model of involvement can be tailored by adopting a flexible approach to take account of the context and complexities of a multi-site trial
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