155 research outputs found
Gauged D=7 Supergravity on the S**1/Z_2 Orbifold
We construct the most general couplings of a bulk seven-dimensional
Yang-Mills-Einstein N=2 supergravity with a boundary six-dimensional chiral
N=(0,1) theory of vectors and charged hypermultiplets. The boundary consists of
two brane worlds sitting at the fixed points of an S^1/Z_2 compactification of
the seven-dimensional bulk supergravity. The resulting 6D massless spectrum
surviving the orbifold projection is anomalous. By introducing boundary fields
at the orbifold fixed points, we show that all anomalies are cancelled by a
Green-Schwarz mechanism. In addition, all couplings of the boundary fields to
the bulk are completely specified by supersymmetry. We emphasize that there is
no bulk Chern-Simons term to cancel the anomalies. The latter is traded for a
Green-Schwarz term which emerges in the boundary theory after a duality
transformation implemented to construct the bulk supergravity.Comment: LaTeX, 42 pages; typos corrected, reference added, version to appear
in Phys. Rev.
Series solutions for a static scalar potential in a Salam-Sezgin Supergravitational hybrid braneworld
The static potential for a massless scalar field shares the essential
features of the scalar gravitational mode in a tensorial perturbation analysis
about the background solution. Using the fluxbrane construction of [8] we
calculate the lowest order of the static potential of a massless scalar field
on a thin brane using series solutions to the scalar field's Klein Gordon
equation and we find that it has the same form as Newton's Law of Gravity. We
claim our method will in general provide a quick and useful check that one may
use to see if their model will recover Newton's Law to lowest order on the
brane.Comment: 5 pages, no figure
The Breadth of Viruses in Human Semen.
Zika virus RNA is frequently detected in the semen of men after Zika virus infection. To learn more about persistence of viruses in genital fluids, we searched PubMed for relevant articles. We found evidence that 27 viruses, across a broad range of virus families, can be found in human semen
A systematic review of the clinical profile of patients with bubonic plague and the outcome measures used in research settings
BACKGROUND: Plague is a zoonotic disease that, despite affecting humans for more than 5000 years, has historically been the subject of limited drug development activity. Drugs that are currently recommended in treatment guidelines have been approved based on animal studies alone-no pivotal clinical trials in humans have yet been completed. As a result of the sparse clinical research attention received, there are a number of methodological challenges that need to be addressed in order to facilitate the collection of clinical trial data that can meaningfully inform clinicians and policy-makers. One such challenge is the identification of clinically-relevant endpoints, which are informed by understanding the clinical characterisation of the disease-how it presents and evolves over time, and important patient outcomes, and how these can be modified by treatment.METHODOLOGY/PRINCIPAL FINDINGS: This systematic review aims to summarise the clinical profile of 1343 patients with bubonic plague described in 87 publications, identified by searching bibliographic databases for studies that meet pre-defined eligibility criteria. The majority of studies were individual case reports. A diverse group of signs and symptoms were reported at baseline and post-baseline timepoints-the most common of which was presence of a bubo, for which limited descriptive and longitudinal information was available. Death occurred in 15% of patients; although this varied from an average 10% in high-income countries to an average 17% in low- and middle-income countries. The median time to death was 1 day, ranging from 0 to 16 days.CONCLUSIONS/SIGNIFICANCE: This systematic review elucidates the restrictions that limited disease characterisation places on clinical trials for infectious diseases such as plague, which not only impacts the definition of trial endpoints but has the knock-on effect of challenging the interpretation of a trial's results. For this reason and despite interventional trials for plague having taken place, questions around optimal treatment for plague persist.</p
Coherently coupled photonic-crystal surface-emitting laser array
The realization of a 1 × 2 coherently coupled photonic crystal surface emitting laser array is reported. New routes to power scaling are discussed and the electronic control of coherence is demonstrated
Anomaly-Free Brane Worlds in Seven Dimensions
We present an orbifold compactification of the minimal seven dimensional
supergravity. The vacuum is a slice of AdS_7 where six-branes of opposite
tension are located at the orbifold fixed points. The cancellation of gauge and
gravitational anomalies restricts the gauge group and matter content on the
boundaries. In addition anomaly cancellation fixes the boundary gauge couplings
in terms of the gravitational constant, and the mass parameter of the
Chern-Simons term.Comment: 10 pages, LaTeX; v2: typos corrected, references adde
Concordia Station, Dome C, Antarctica as a Ground-Based Analog for Spaceflight/Planetary Exploration: The CHOICE* Immunology Study
No abstract availabl
Time to reconsider the role of ribavirin in Lassa fever
Ribavirin is the only available Lassa fever treatment. The rationale for using ribavirin is based on one clinical study conducted in the early 1980s. However, reanalysis of previous unpublished data reveals that ribavirin may actually be harmful in some Lassa fever patients. An urgent reevaluation of ribavirin is therefore needed
Lack of Evidence for Ribavirin Treatment of Lassa Fever in Systematic Review of Published and Unpublished Studies
Ribavirin has been used widely to treat Lassa fever in West Africa since the 1980s. However, few studies have systematically appraised the evidence for its use. We conducted a systematic review of published and unpublished literature retrieved from electronic databases and gray literature from inception to March 8, 2022. We identified 13 studies of the comparative effectiveness of ribavirin versus no ribavirin treatment on mortality outcomes, including unpublished data from a study in Sierra Leone provided through a US Freedom of Information Act request. Although ribavirin was associated with decreased mortality rates, results of these studies were at critical or serious risk for bias when appraised using the ROBINS-I tool. Important risks for bias related to lack of control for confounders, immortal time bias, and missing outcome data. Robust evidence supporting the use of ribavirin in Lassa fever is lacking. Well-conducted clinical trials to elucidate the effectiveness of ribavirin for Lassa fever are needed
Jet vetoing and Herwig++
We investigate the simulation of events with gaps between jets with a veto on
additional radiation in the gap in Herwig++. We discover that the
currently-used random treatment of radiation in the parton shower is generating
some unphysical behaviour for wide-angle gluon emission in QCD 2 to 2
scatterings. We explore this behaviour quantitatively by making the same
assumptions as the parton shower in the analytical calculation. We then modify
the parton shower algorithm in order to correct the simulation of QCD
radiation.Comment: 18 pages, 11 figure
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