3,855 research outputs found
The Opioid-related Syndemic in Rural Northern New England:Findings from the DISCERNNE Study
This presentation will discuss the risk and resource environment surrounding the syndemic of opioid use disorder, HCV and overdose in rural communities in the northern New England, and opportunities to prevent Scott County-like HIV outbreaks. These findings are from the Drug Injector Surveillance and Care Enhancement in Rural Northern New England (DISCERNNE) study
Multidimensional perfect fluid cosmology with stable compactified internal dimensions
Multidimensional cosmological models in the presence of a bare cosmological
constant and a perfect fluid are investigated under dimensional reduction to
4-dimensional effective models. Stable compactification of the internal spaces
is achieved for a special class of perfect fluids. The external space behaves
in accordance with the standard Friedmann model. Necessary restrictions on the
parameters of the models are found to ensure dynamical behavior of the external
(our) universe in agreement with observations.Comment: 11 pages, Latex2e, uses IOP packages, submitted to Class.Quant.Gra
Explaining the Electroweak Scale and Stabilizing Moduli in M Theory
In a recent paper \cite{Acharya:2006ia} it was shown that in theory vacua
without fluxes, all moduli are stabilized by the effective potential and a
stable hierarchy is generated, consistent with standard gauge unification. This
paper explains the results of \cite{Acharya:2006ia} in more detail and
generalizes them, finding an essentially unique de Sitter (dS) vacuum under
reasonable conditions. One of the main phenomenological consequences is a
prediction which emerges from this entire class of vacua: namely gaugino masses
are significantly suppressed relative to the gravitino mass. We also present
evidence that, for those vacua in which the vacuum energy is small, the
gravitino mass, which sets all the superpartner masses, is automatically in the
TeV - 100 TeV range.Comment: 73 pages, 39 figures, Minor typos corrected, Figures and References
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Symmetric Strategy Improvement
Symmetry is inherent in the definition of most of the two-player zero-sum
games, including parity, mean-payoff, and discounted-payoff games. It is
therefore quite surprising that no symmetric analysis techniques for these
games exist. We develop a novel symmetric strategy improvement algorithm where,
in each iteration, the strategies of both players are improved simultaneously.
We show that symmetric strategy improvement defies Friedmann's traps, which
shook the belief in the potential of classic strategy improvement to be
polynomial
Non-minimal couplings in two dimensional gravity: a quantum investigation
We investigate the quantum effects of the non-minimal matter-gravity
couplings derived by Cangemi and Jackiw in the realm of a specific fermionic
theory, namely the abelian Thirring model on a Riemann surface of genus zero
and one. The structure and the strength of the new interactions are seen to be
highly constrained, when the topology of the underlying manifold is taken into
account. As a matter of fact, by requiring to have a well-defined action, we
are led both to quantization rules for the coupling constants and to selection
rules for the correlation functions. Explicit quantum computations are carried
out in genus one (torus). In particular the two-point function and the chiral
condensate are carefully derived for this case. Finally the effective
gravitational action, coming from integrating out the fermionic degrees of
freedoom, is presented. It is different from the standard Liouville one: a new
non-local functional of the conformal factor arises and the central charge is
improved, depending also on the Thirring coupling constant. This last feature
opens the possibility of giving a new explicit representation of the minimal
series in terms of a fermionic interacting model.Comment: Latex, 41 Page
G_2 Domain Walls in M-theory
M-theory is considered in its low-energy limit on a G_2 manifold with
non-vanishing flux. Using the Killing spinor equations for linear flux, an
explicit set of first-order bosonic equations for supersymmetric solutions is
found. These solutions describe a warped product of a domain wall in
four-dimensional space-time and a deformed G_2 manifold. It is shown how these
domain walls arise from the perspective of the associated four-dimensional N=1
effective supergravity theories. We also discuss the inclusion of membrane and
M5-brane sources.Comment: 30 pages, Late
Experimental and numerical analysis of mold filling in rotational molding
This work focuses on the development of a numerical mold filling simulation for the rotational molding process. In the rotational molding process, a dry fiber preform is placed in a mold and impregnated with a thermoset matrix under rotation. Additionally, metallic load introduction elements can be inserted into the mold and joined with co-curing or form-fit, resulting in hybrid drive shafts or tie rods. The numerical model can be used to simulate the impregnation of the preform. Based on the resin transfer molding process, an OpenFOAM solver is extended for the rotational molding process. Permeability, kinetic and curing models are selected and adapted to the materials used. A wireless measurement solution with a capacitive sensor is developed to validate the model. Comparisons between measurements and numerically calculated impregnation times to reach the capacitive sensor with the matrix show good quality of the developed model. The average deviation between calculated result and measured mean values in the experiment is 43.8% the maximum deviation is 65.8% . The model can therefore be used to predict the impregnation progress and the curing state
Birmingham’s Eastside story: making steps towards sustainability?
Sustainability has come to play a dominant discursive role in the UK planning system, particularly relating to urban regeneration. The purpose of this paper is to evaluate the role that sustainability plays in a major regeneration
programme, known as Eastside, currently underway in Birmingham, the UK. That this ÂŁ6 billion redevelopment is now widely talked about by such key players as Birmingham City Council and the Regional Development Agency, Advantage West Midlands, as having a central sustainability agenda points to the growing importance of the ideal of sustainability in planning and regeneration agendas. In this paper, we investigate in detail how and why sustainability has become part of the planning discourse for Eastside and critically evaluate what impact, if any, this is having on public policy decision-making
Stable Topologies of Event Horizon
In our previous work, it was shown that the topology of an event horizon (EH)
is determined by the past endpoints of the EH. A torus EH (the collision of two
EH) is caused by the two-dimensional (one-dimensional) set of the endpoints. In
the present article, we examine the stability of the topology of the EH. We see
that a simple case of a single spherical EH is unstable. Furthermore, in
general, an EH with handles (a torus, a double torus, ...) is structurally
stable in the sense of catastrophe theory.Comment: 21 pages, revtex, five figures containe
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