9,609 research outputs found
Multi-Boson Interactions at the LHC
This review covers results on the production of all possible electroweak
boson pairs and 2-to-1 vector boson fusion at the CERN Large Hadron Collider
(LHC) in proton-proton collisions at a center of mass energy of 7 and 8 TeV.
The data were taken between 2010 and 2012. Limits on anomalous triple gauge
couplings (aTGCs) then follow. In addition, data on electroweak triple gauge
boson production and 2-to-2 vector boson scattering yield limits on anomalous
quartic gauge boson couplings (aQGCs). The LHC hosts two general purpose
experiments, ATLAS and CMS, which have both reported limits on aTGCs and aQGCs
which are herein summarized. The interpretation of these limits in terms of an
effective field theory is reviewed, and recommendations are made for testing
other types of new physics using multi-gauge boson production.Comment: 53 pages, 48 figures, 4 table
A Deep Multicolor Survey I. Imaging Observations and Catalog of Stellar Objects
We have used the KPNO 4-meter Mayall telescope to image 0.83 square degrees
of sky in six fields at high galactic latitude in six filters spanning
3000-10000\AA\ to magnitude limits ranging from 22.1 to 23.8. We have assembled
a catalog of 21,375 stellar objects detected in the fields for use primarily in
conducting a multicolor search for quasars. This paper describes the data
reduction techniques used on the CCD data, the methods used to construct the
stellar object catalog, and the simulations performed to understand its
completeness and contamination.Comment: To Appear in ApJ Supplement, 1996. 168k uuencoded gunzipped tarred
tex file (requires aas2pp4.sty and tighten.sty) and 4 PostScript figures.
Also available at http://astro.as.arizona.edu/~pathall/astro.html#preprint
An Adaptive Parallel Algorithm for Computing Connected Components
We present an efficient distributed memory parallel algorithm for computing
connected components in undirected graphs based on Shiloach-Vishkin's PRAM
approach. We discuss multiple optimization techniques that reduce communication
volume as well as load-balance the algorithm. We also note that the efficiency
of the parallel graph connectivity algorithm depends on the underlying graph
topology. Particularly for short diameter graph components, we observe that
parallel Breadth First Search (BFS) method offers better performance. However,
running parallel BFS is not efficient for computing large diameter components
or large number of small components. To address this challenge, we employ a
heuristic that allows the algorithm to quickly predict the type of the network
by computing the degree distribution and follow the optimal hybrid route. Using
large graphs with diverse topologies from domains including metagenomics, web
crawl, social graph and road networks, we show that our hybrid implementation
is efficient and scalable for each of the graph types. Our approach achieves a
runtime of 215 seconds using 32K cores of Cray XC30 for a metagenomic graph
with over 50 billion edges. When compared against the previous state-of-the-art
method, we see performance improvements up to 24x
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Astex microgravity experiment: simulated asteroid regoliths
AstEx is a microgravity experiment selected to fly on ESA's 51st Microgravity Research Campaign in November 2009. The experiment will investigate the dynamics of regolith on asteroid surfaces. Despite their very low surface gravities, asteroids exhibit a number of different geological processes involving granular matter. Understanding the mechanical response of this granular material subject to external forces in microgravity conditions is vital to the design of a successful asteroid sub-surface sampling mechanism, and in the interpretation of the fascinating geology on an asteroid. The AstEx experiment uses a microgravity modified Taylor-Couette shear cell to investigate granular flow caused by shear forces under the conditions of parabolic flight microgravity. It is intended to determine how a steady state granular flow is achieved in microgravity conditions, and what effect prior shear history has on the timescales involved in initiating a steady state flow in a granular material. Presented are the technical details of the AstEx experimental design with particular emphasis on how the team have designed the equipment specifically for the parabolic flight microgravity environment
Children's eating behaviours: The importance of the family setting
Childhood obesity has become a major public health challenge. Whilst it is accepted that the aetiology of obesity is complex, there is very little that targets the home environment and specifically looks at the family setting and how this influences children's eating behaviours. This research aimed to redress the balance by alerting people to the importance of the family environment as a contributory factor for childhood obesity. Using a grounded theory approach, 'Ordering of eating' highlights the importance of the family setting and demonstrates how micro and macro order influences the development of children's eating behaviours. © Journal compilation © 2008 Royal Geographical Society (with the Institute of British Geographers)
HTLV-1 p30(II): selective repressor of gene expression
Human T-lymphotropic virus type-1 (HTLV-1) is a complex retrovirus that causes adult T-cell leukemia/lymphoma (ATL) and is implicated in a variety of lymphocyte-mediated disorders. HTLV-1 pX ORF II encodes two proteins, p13(II )and p30(II )whose roles are beginning to be defined in the virus life cycle. Previous studies indicate the importance of these viral proteins in the ability of the virus to maintain viral loads and persist in an animal model of HTLV-1 infection. Intriguing new studies indicate that p30(II )is a multifunctional regulator that differentially modulates CREB and Tax-responsive element-mediated transcription through its interaction with CREB-binding protein (CBP)/p300 and specifically binds and represses tax/rex mRNA nuclear export. A new study characterized the role of p30(II )in regulation of cellular gene expression using comprehensive human gene arrays. Interestingly, p30(II )is an overall repressor of cellular gene expression, while selectively favoring the expression of regulatory gene pathways important to T lymphocytes. These new findings suggest that HTLV-1, which is associated with lymphoproliferative diseases, uses p30(II )to selectively repress cellular and viral gene expression to favor the survival of cellular targets ultimately resulting in leukemogenesis
HTLV-1 Tax-1 interacts with SNX27 to regulate cellular localization of the HTLV-1 receptor molecule, GLUT1
An estimated 10–20 million people worldwide are infected with human T cell leukemia virus type 1 (HTLV-1), with endemic areas of infection in Japan, Australia, the Caribbean, and Africa. HTLV-1 is the causative agent of adult T cell leukemia (ATL) and HTLV-1 associated myopathy/tropic spastic paraparesis (HAM/TSP). HTLV-1 expresses several regulatory and accessory genes that function at different stages of the virus life cycle. The regulatory gene Tax-1 is required for efficient virus replication, as it drives transcription of viral gene products, and has also been demonstrated to play a key role in the pathogenesis of the virus. Several studies have identified a PDZ binding motif (PBM) at the carboxyl terminus of Tax-1 and demonstrated the importance of this domain for HTLV-1 induced cellular transformation. Using a mass spectrometry-based proteomics approach we identified sorting nexin 27 (SNX27) as a novel interacting partner of Tax-1. Further, we demonstrated that their interaction is mediated by the Tax-1 PBM and SNX27 PDZ domains. SNX27 has been shown to promote the plasma membrane localization of glucose transport 1 (GLUT1), one of the receptor molecules of the HTLV-1 virus, and the receptor molecule required for HTLV-1 fusion and entry. We postulated that Tax-1 alters GLUT1 localization via its interaction with SNX27. We demonstrate that over expression of Tax-1 in cells causes a reduction of GLUT1 on the plasma membrane. Furthermore, we show that knockdown of SNX27 results in increased virion release and decreased HTLV-1 infectivity. Collectively, we demonstrate the first known mechanism by which HTLV-1 regulates a receptor molecule post-infection.</div
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