231 research outputs found
Substance abuse and psychiatric co-morbidities: a case study of patients at Mathari Psychiatric Hospital, Nairobi, Kenya
Substance abuse co-morbidity with psychiatric disorders is common and has been widely reported, except in Kenya. This study aimed to determine the prevalence, pattern and socio-economic burden of a dual diagnosis of substance abuse disorder and other psychiatric conditions. This was a cross-sectional descriptive study of 691 patients admitted at Mathari hospital. Only 42 patients had a first working diagnosis of substance abuse but nearly thirty-five percent of the patients
scored for a Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) diagnosis of alcohol dependance/abuse. There was high co-morbidity of alcohol abuse/dependence with opiate, sedative and 'khat' use, as well as with mood and other psychotic disorders. Substance abuse disorders correlated significantly with other psychiatric disorders. Only 12 patients were in a drug rehabilitation unit, all of whom had a dual psychiatric diagnosis of affective disorder.
There were high co-morbidity rates of substance abuse in both general psychiatric wards and drug rehabilitation units.
KEY WORDS: substance abuse, co-morbidity, psychiatric disorders, Keny
Molten Salt Thermal Energy Storage Systems
The feasibility of storing thermal energy at temperatures of 450 C to 535 C in the form of latent heat of fusion was examined for over 30 inorganic salts and salt mixtures. Alkali carbonate mixtures were chosen as phase-change storage materials in this temperature range because of their relatively high storage capacity and thermal conductivity, moderate cost, low volumetric expansion upon melting, low corrosivity, and good chemical stability. Means of improving heat conduction through the solid salt were explored
Winding number and non-BPS bound states of walls in nonlinear sigma models
Non-supersymmetric multi-wall configurations are generically unstable. It is
proposed that the stabilization in compact space can be achieved by introducing
a winding number into the model. A BPS-like bound is studied for the energy of
configuration with nonvanishing winding number. Winding number is implemented
in an supersymmetric nonlinear sigma model with two chiral scalar
fields and a bound states of BPS and anti-BPS walls is found to exist in
noncompact spaces. Even in compactified space , this nontrivial bound
state persists above a critical radius of the compact dimension.Comment: 20pages, 14 figures, minor misprint corrections, figures added,
explanation of winding number adde
An Extension for Direct Gauge Mediation of Metastable Supersymmetry Breaking
We study the direct mediation of metastable supersymmetry breaking by a
\Phi^2-deformation to the ISS model and extend it by splitting both Tr\Phi and
Tr\Phi^2 terms in the superpotential and gauging the flavor symmetry. We find
that with such an extension the enough long-lived metastable vacua can be
obtained and the proper gaugino masses can be generated. Also, this allows for
constructing a kind of models which can avoid the Landau pole problem.
Especially, in our metastable vacua there exist a large region for the
parameter m_3 which can satisfy the phenomenology requirements and allow for a
low SUSY breaking scale (\sim 100 TeV).Comment: version in Europhys. Let
Non-Abelian Walls in Supersymmetric Gauge Theories
The Bogomol'nyi-Prasad-Sommerfield (BPS) multi-wall solutions are constructed
in supersymmetric U(N_C) gauge theories in five dimensions with N_F(>N_C)
hypermultiplets in the fundamental representation. Exact solutions are obtained
with full generic moduli for infinite gauge coupling and with partial moduli
for finite gauge coupling. The generic wall solutions require nontrivial
configurations for either gauge fields or off-diagonal components of adjoint
scalars depending on the gauge. Effective theories of moduli fields are
constructed as world-volume gauge theories. Nambu-Goldstone and
quasi-Nambu-Goldstone scalars are distinguished and worked out. Total moduli
space of the BPS non-Abelian walls including all topological sectors is found
to be the complex Grassmann manifold SU(N_F) / [SU(N_C) x SU(N_F-N_C) x U(1)]
endowed with a deformed metric.Comment: 62 pages, 17 figures, the final version in PR
Composite Higgs Search at the LHC
The Higgs boson production cross-sections and decay rates depend, within the
Standard Model (SM), on a single unknown parameter, the Higgs mass. In
composite Higgs models where the Higgs boson emerges as a pseudo-Goldstone
boson from a strongly-interacting sector, additional parameters control the
Higgs properties which then deviate from the SM ones. These deviations modify
the LEP and Tevatron exclusion bounds and significantly affect the searches for
the Higgs boson at the LHC. In some cases, all the Higgs couplings are reduced,
which results in deterioration of the Higgs searches but the deviations of the
Higgs couplings can also allow for an enhancement of the gluon-fusion
production channel, leading to higher statistical significances. The search in
the H to gamma gamma channel can also be substantially improved due to an
enhancement of the branching fraction for the decay of the Higgs boson into a
pair of photons.Comment: 32 pages, 16 figure
Domain Wall Junction in N=2 Supersymmetric QED in four dimensions
An exact solution of domain wall junction is obtained in N=2 supersymmetric
(SUSY) QED with three massive hypermultiplets. The junction preserves two out
of eight SUSY. Both a (magnetic) Fayet-Iliopoulos (FI) term and complex masses
for hypermultiplets are needed to obtain the junction solution. There are zero
modes corresponding to spontaneously broken translation, SUSY, and U(1). All
broken and unbroken SUSY charges are explicitly worked out in the Wess-Zumino
gauge in N=1 superfields as well as in components. The relation to models in
five dimensions is also clarified.Comment: 27 pages, 6 figures, comments on zero modes added, a few references
adde
Dynamics of Weyl Scale Invariant non-BPS p=3 Branes
In this paper a Weyl scale invariant brane scenario is introduced, with
the brane embedded in a higher dimensional bulk space with
Super--Weyl symmetry. Its action, which describes its long wave oscillation
modes into the ambient superspace and breaks the target symmetry down to the
lower dimensional Weyl W(1,3) symmetry, is constructed by the approach of coset
method.Comment: 12 pages, modified versio
Nonanomalous Discrete R-Symmetry and Light Gravitino
We discuss nonanomalous R-symmetry in the supersymmetric grand unified
theories. In particular, we explore anomaly-free solutions predicting the
gravitino mass in the range of 10^{-3} eV \lsim m_{3/2} \lsim 1 TeV when the
-parameter is fixed to be . In the minimal SU(5) GUT, we
have shown that is obtained only if the gravitino is
ultralight with mass . If extra fields or are introduced, many solutions
predicting m_{3/2} \gsim 10^{-3} eV are found. The R-parity is violated due
to the vacuum expectation value of the superpotential, but it is controlled by
the discrete R-symmetry. We find that the R-parity violating couplings are
naturally suppressed much below the experimental bounds for some charge
assignments. These charge assignments predict light gravitino with masses of
order --. These discrete R-symmetries
can be considered as solutions to the -problem in low energy supersymmetry
breaking models such as the gauge mediation.Comment: 20 pages, no figure. v2: minor corrections, references added, "Note
Added" in Summary adde
The Two Faces of Anomaly Mediation
Anomaly mediation is a ubiquitous source of supersymmetry (SUSY) breaking
which appears in almost every theory of supergravity. In this paper, we show
that anomaly mediation really consists of two physically distinct phenomena,
which we dub "gravitino mediation" and "Kahler mediation". Gravitino mediation
arises from minimally uplifting SUSY anti-de Sitter (AdS) space to Minkowski
space, generating soft masses proportional to the gravitino mass. Kahler
mediation arises when visible sector fields have linear couplings to SUSY
breaking in the Kahler potential, generating soft masses proportional to beta
function coefficients. In the literature, these two phenomena are lumped
together under the name "anomaly mediation", but here we demonstrate that they
can be physically disentangled by measuring associated couplings to the
goldstino. In particular, we use the example of gaugino soft masses to show
that gravitino mediation generates soft masses without corresponding goldstino
couplings. This result naively violates the goldstino equivalence theorem but
is in fact necessary for supercurrent conservation in AdS space. Since
gravitino mediation persists even when the visible sector is sequestered from
SUSY breaking, we can use the absence of goldstino couplings as an unambiguous
definition of sequestering.Comment: 21 pages, 1 table; v2, references added, extended discussion in
introduction and appendix; v3, JHEP versio
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