3,946 research outputs found
The WIMP Forest: Indirect Detection of a Chiral Square
The spectrum of photons arising from WIMP annihilation carries a detailed
imprint of the structure of the dark sector. In particular, loop-level
annihilations into a photon and another boson can in principle lead to a series
of lines (a WIMP forest) at energies up to the WIMP mass. A specific model
which illustrates this feature nicely is a theory of two universal extra
dimensions compactified on a chiral square. Aside from the continuum emission,
which is a generic prediction of most dark matter candidates, we find a
"forest" of prominent annihilation lines that, after convolution with the
angular resolution of current experiments, leads to a distinctive (2-bump plus
continuum) spectrum, which may be visible in the near future with the Fermi
Gamma-Ray Space Telescope (formerly known as GLAST).Comment: 11 pages, 4 figure
A Case of Cholangitis Glandularis Proliferans and Cholangiocarcinoma of the Common Bile Duct
A case of Cholangitis Glandularis Proliferans (CAGP) in association with a cholangiocarcinoma of the
common bile duct as described. This is the eighth case of CAGP described and the second association
with cholangiocarcinoma
Flavor changing scalar couplings and production at hadron colliders
We calculate the contributions of the flavor changing scalar ()
couplings arised from topcolor-assisted technicolor () models at
tree-level to the and production at the Tevatron and
experiments. We find that the production cross sections are very small at the
Tevatron with , which is smaller than 5 fb in most of the
parameter space of models. However, the virtual effects of the
couplings on the production can be easily detected at the
with via the final state
().Comment: 10 pages,5 figure
Effects of lesions of the subthalamic nucleus/zona incerta area and dorsomedial striatum on attentional set-shifting in the rat
This work was supported by The Wellcome Trust (project Grant 051945/z/97). Andrew Blackwell was in receipt of a BBSRC Studentship.Patients with Parkinson’s disease show cognitive impairments, including difficulty in shifting attention between perceptual dimensions of complex stimuli. Inactivation of the subthalamic nucleus (STN) has been shown to be effective in ameliorating the motor abnormalities associated with striatal dopamine depletion, but it is possible that STN inactivation might result in additional, perhaps attentional, deficits. This study examined the effects of: dopamine depletion from the dorsomedial striatum (DMS); lesions of the STN area; and the effects of the two lesions together, on the ability to shift attentional set in the rat. In a single session, rats performed the intradimensional/extradimensional (ID/ED) test of attentional set-shifting. This comprises a series of seven, two-choice discriminations, including acquisitions of novel discriminations in which the relevant stimulus is either in the currently-attended dimension (ID) or the currently-unattended dimension (ED shift) and reversals following each acquisition stage. Bilateral lesions were made by injection of 6-hydroxydopamine into the DMS, resulting in a selective impairment in reversal learning. Large bilateral ibotenic acid lesions centred on the STN resulted in an increase in trials to criterion in the initial stages, but learning rate improved within the session. There was no evidence of a ‘cost’ of set-shifting – the ED stage was completed in fewer trials than the ID stage – and neither was there a cost of reversal learning. Strikingly, combined lesions of both regions did not resemble the effects of either lesion alone and resulted in no apparent deficits.Publisher PDFPeer reviewe
Petrologic evidence for pressure-temperature conditions and recent reheating of andesitic magma erupting at Soufriere Hills Volcano, Montserrat, WI
PHIDL: Python CAD layout and geometry creation for nanolithography
Computer-aided design (CAD) has become a critical element in the creation of
nanopatterned structures and devices. In particular, with the increased
adoption of easy-to-learn programming languages like Python there has been a
significant rise in the amount of lithographic geometries generated through
scripting and programming. However, there are currently unaddressed gaps in
usability for open-source CAD tools -- especially those in the GDSII design
space -- that prevent wider adoption by scientists and students who might
otherwise benefit from scripted design. For example, constructing relations
between adjacent geometries is often much more difficult than necessary --
spacing a resonator structure a few micrometers from a readout structure often
requires manually-coding the placement arithmetic. While inconveniences like
this can be overcome by writing custom functions, they are often significant
barriers to entry for new users or those less familiar with programming. To
help streamline the design process and reduce barrier to entry for scripting
designs, we have developed PHIDL, an open-source GDSII-based CAD tool for
Python 2 and 3
Measuring the W-t-b Interaction at the ILC
The large top quark mass suggests that the top plays a pivotal role in
Electroweak symmetry-breaking dynamics and, as a result, may have modified
couplings to Electroweak bosons. Hadron colliders can provide measurements of
these couplings at the ~10% level, and one of the early expected triumphs of
the International Linear Collider is to reduce these uncertainties to the per
cent level. In this article, we propose the first direct measurement of the
Standard Model W-t-b coupling at the ILC, from measurements of t tbar-like
signals below the t tbar production threshold. We estimate that the ILC with
100 fb^{-1} can measure a combination of the coupling and top width to high
precision, and when combined with a direct measurement of the top width from
the above-threshold scan, results in a model-independent measurement of the
W-t-b interaction of the order of ~ 3%
Permanent draft genome sequence of Vibrio tubiashii strain NCIMB 1337 (ATCC19106).
This is the final version of the article. Available from BioMed Central via the DOI in this record.Vibrio tubiashii NCIMB 1337 is a major and increasingly prevalent pathogen of bivalve mollusks, and shares a close phylogenetic relationship with both V. orientalis and V. coralliilyticus. It is a Gram-negative, curved rod-shaped bacterium, originally isolated from a moribund juvenile oyster, and is both oxidase and catalase positive. It is capable of growth under both aerobic and anaerobic conditions. Here we describe the features of this organism, together with the draft genome and annotation. The genome is 5,353,266 bp long, consisting of two chromosomes, and contains 4,864 protein-coding and 86 RNA genes.We wish to thank i-G Peninsula (Prospect Place, the Hoe, Plymouth, Devon, UK) for providing funding for this project, and NBAF Edinburgh for performing the sequencing
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