1,769 research outputs found
The Dengue virus in Nepal: gaps in diagnosis and surveillance.
BACKGROUND: The introduction of the dengue virus (DENV) in Nepal is recent, first reports date back to 2004 from a Japanese traveller and limited information is available about DENV infection in the Nepali population. Within a decade after the first DENV detection, it is now endemic in multiple districts of Nepal with approximately 11.2 million people residing in the Terai belt being at risk of DENV infection. Sporadic cases of DENV infection have been reported every year for the past decade during the monsoon season, mainly in the Terai region. METHODS: Medline/Embase/Cochrane databases were reviewed for reports on the burden of dengue infection, diagnostic methods, and national surveillance. RESULTS: Four outbreaks were reported since 2004 including the diagnosis of all serotypes in 2006 and predominance of a single serotype in 2010 (DENV-1), 2013 (DENV-2), and 2016 (DENV-1). The clinical diagnoses showed a predominance of dengue fever while 4/917 (0.4%), 8/642 (1.2%) and 8/1615 (0.4%) dengue haemorrhagic fever/dengue shock syndrome cases were identified during the outbreaks in 2010, 2013 and 2016, respectively. The number of cases reported in males was significantly higher (67.4%) than in females. Disease occurrence was primarily found in the Terai region until 2010 and was increasingly detected in the Hilly region in 2016. CONCLUSION: In Nepal currently weak diagnostic facilities, very limited research on mosquitoes vectors, and poor surveillance of dengue leading to inappropriate detection and control of DENV. We surmise that improved basic research and epidemiological training courses for local scientists and laboratory personal at national and international level will help better understand the evolution and distribution of DENV transmission and its eventual control
Demographic, Behavioral and Perceptual Comparisons of the U.S. Visitor Experience with Group Package Tours and Free Independent Travel to China
U.S. visitor demand for the China travel experience is anticipated to rise significantly through 2105, causing the Chinese government to employ 100 million service providers over the next six years and raising concern about service delivery and perceptions of the on-site China experience. In an effort to better understand these issues concerning U.S. visitors, this study investigated two specific types of U.S. travelers to China: Group Package Tour (GPT) visitors and Free Independent Travel (FIT) visitors. Results indicated that GPT visitors were more likely to be older and have higher household income than FIT visitors. Four trip-related characteristics of GPT and FIT visitors were found to be significantly different, with GPT visitors showing higher levels of satisfaction with the overall China on-site travel experience
Possible explanation of the discrepancy of the light-cone QCD sum rule calculation of g(D*Dpi) coupling with experiment
The introduction of an explicit negative radial excitation contribution in
the hadronic side of the light cone QCD sum rule (LCSR) of Belyaev, Braun,
Khodjamirian and Ruckl, can explain the large experimental value of g(D*Dpi),
recently measured by CLEO. At the same time, it considerably improves the
stability of the sum rule when varying the Borel parameter.Comment: 9 pages, 1 PostScript figure
Supersymmetric AdS_3, AdS_2 and Bubble Solutions
We present new supersymmetric AdS_3 solutions of type IIB supergravity and
AdS_2 solutions of D=11 supergravity. The former are dual to conformal field
theories in two dimensions with N=(0,2) supersymmetry while the latter are dual
to conformal quantum mechanics with two supercharges. Our construction also
includes AdS_2 solutions of D=11 supergravity that have non-compact internal
spaces which are dual to three-dimensional N=2 superconformal field theories
coupled to point-like defects. We also present some new bubble-type solutions,
corresponding to BPS states in conformal theories, that preserve four
supersymmetries.Comment: v2: 33 pages, published version in JHE
AdS spacetimes from wrapped D3-branes
We derive a geometrical characterisation of a large class of AdS_3 and AdS_2
supersymmetric spacetimes in IIB supergravity with non-vanishing five-form flux
using G-structures. These are obtained as special cases of a class of
supersymmetric spacetimes with an or (time)
factor that are associated with D3-branes wrapping calibrated 2- or 3- cycles,
respectively, in manifolds with SU(2), SU(3), SU(4) and G_2 holonomy. We show
how two explicit AdS solutions, previously constructed in gauged supergravity,
satisfy our more general G-structure conditions. For each explicit solution we
also derive a special holonomy metric which, although singular, has an
appropriate calibrated cycle. After analytic continuation, some of the classes
of AdS spacetimes give rise to known classes of BPS bubble solutions with
, , and
symmetry. These have 1/2, 1/4 and 1/8 supersymmetry,
respectively. We present a new class of 1/8 BPS geometries with
symmetry, obtained by analytic continuation of the
class of AdS spacetimes associated with D3-branes wrapped on associative
three-cycles.Comment: 1+30 pages; v2, references added; v3, typos corrected, reference
adde
Geometries with Killing Spinors and Supersymmetric AdS Solutions
The seven and nine dimensional geometries associated with certain classes of
supersymmetric and solutions of type IIB and D=11 supergravity,
respectively, have many similarities with Sasaki-Einstein geometry. We further
elucidate their properties and also generalise them to higher odd dimensions by
introducing a new class of complex geometries in dimensions, specified
by a Riemannian metric, a scalar field and a closed three-form, which admit a
particular kind of Killing spinor. In particular, for , we show that
when the geometry in dimensions is a cone we obtain a class of
geometries in dimensions, specified by a Riemannian metric, a scalar
field and a closed two-form, which includes the seven and nine-dimensional
geometries mentioned above when , respectively. We also consider various
ansatz for the geometries and construct infinite classes of explicit examples
for all .Comment: 28 page
M-Theory solutions with AdS factors
Solutions of D=7 maximal gauged supergravity are constructed with metrics
that are a product of a n-dimensional anti-de Sitter (AdS) space, with
n=2,3,4,5, and certain Einstein manifolds. The gauge fields have the same form
as in the recently constructed solutions describing the near-horizon limits of
M5-branes wrapping supersymmetric cycles. The new solutions do not preserve any
supersymmetry and can be uplifted to obtain new solutions of D=11 supergravity,
which are warped and twisted products of the D=7 metric with a squashed
four-sphere. Some aspects of the stability of the solutions are discussed.Comment: 30 pages. References adde
Nematic liquid crystal alignment on chemical patterns
Patterned Self-Assembled Monolayers (SAMs) promoting both homeotropic and planar degenerate alignment of 6CB and 9CB in their nematic phase, were created using microcontact printing of functionalised organothiols on gold films. The effects of a range of different pattern geometries and sizes were investigated, including stripes, circles and checkerboards. EvanescentWave Ellipsometry was used to study the orientation of the liquid crystal (LC) on these patterned surfaces during the isotropic-nematic phase transition. Pretransitional growth of a homeotropic layer was observed on 1 ¹m homeotropic aligning stripes, followed by a homeotropic mono-domain state prior to the
bulk phase transition. Accompanying Monte-Carlo simulations of LCs aligned on nano-patterned surfaces were also performed. These simulations also showed the presence of the homeotropic mono-domain state prior to the transition.</p
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