Diffractive Higgs Production by AdS Pomeron Fusion

The double diffractive Higgs production at central rapidity is formulated in terms of the fusion of two AdS gravitons/Pomerons first introduced by Brower, Polchinski, Strassler and Tan in elastic scattering. Here we propose a simple self-consistent holographic framework capable of providing phenomenologically compelling estimates of diffractive cross sections at the LHC. As in the traditional weak coupling approach, we anticipate that several phenomenological parameters must be tested and calibrated through factorization for a self-consistent description of other diffractive process such as total cross sections, deep inelastic scattering and heavy quark production in the central region.Comment: 53 pages, 8 figure

Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in acute lung injury to reduce pulmonary dysfunction (HARP-2) trial : study protocol for a randomized controlled trial

Acute lung injury (ALI) is a common devastating clinical syndrome characterized by life-threatening respiratory failure requiring mechanical ventilation and multiple organ failure. There are in vitro, animal studies and pre-clinical data suggesting that statins may be beneficial in ALI. The Hydroxymethylglutaryl-CoA reductase inhibition with simvastatin in Acute lung injury to Reduce Pulmonary dysfunction (HARP-2) trial is a multicenter, prospective, randomized, allocation concealed, double-blind, placebo-controlled clinical trial which aims to test the hypothesis that treatment with simvastatin will improve clinical outcomes in patients with ALI

Gravitational collapse and thermalization in the hard wall model

We study a simple example of holographic thermalization in a confining field theory: the homogeneous injection of energy in the hard wall model. Working in an amplitude expansion, we find black brane formation for sufficiently fast energy injection and a scattering wave solution for sufficiently slow injection. We comment on our expectations for more sophisticated holographic QCD models.Comment: 33 pages, 5 figure

What can biologists say about galaxy evolution ?

It is possible to borrow from a topic of biology called phylogenetic systematics, concepts and tools for a logical and objective classification of galaxies. It is based on observable properties of objects - characters - either qualitative (like morphology) or quantitative (like luminosity, mass or spectrum). Distance analysis can readily be performed using a method called phenetics and based on characters. But the most promising approach is cladistics. It makes use of characters that can exist in at least two states, one being ancestral and the other one derived. Objects are gathered depending on the derived states they share. We illustrate a first application of this method to astrophysics, that we name astrocladistics, with dwarf galaxies from the Local Group.Comment: Kiel Euroconference (2002) "The Evolution of Galaxies III. From Simple Approaches to Self-Consistent Models", Kluwer Academic Publishers (in press

Nucleosome mobilization by ISW2 requires the concerted action of the ATPase and SLIDE domains

The ISWI family of ATP-dependent chromatin remodelers represses transcription by changing nucleosome positioning. The interactions with extranucleosomal DNA and the requirement of a minimal length of extranucleosomal DNA by ISWI mediate the spacing of nucleosomes. ISW2 from Saccharomyces cerevisiae, a member of the ISWI family, has a conserved domain called SLIDE (SANT-like ISWI domain), whose binding to extranucleosomal DNA ~19 bp from the edge of nucleosomes is required for efficiently pushing DNA into nucleosomes and maintaining the unidirectional movement of nucleosomes, as reported here. Loss of SLIDE binding does not perturb ATPase domain binding to the SHL2 site of nucleosomes or its initial movement of DNA inside of nucleosomes. ISW2 has therefore two distinct roles in mobilizing nucleosomes, with the ATPase domain translocating and moving DNA inside nucleosomes, and the SLIDE domain facilitating the entry of linker DNA into nucleosomes

Infrared study of defects in nitrogen-doped electron irradiated silicon

Nitrogen is a key dopant in Czochralski silicon widely used to control properties of Si wafers for applications in the microelectronics industry. Most of these properties are affected by defects and their processes. Here we employ Fourier transform infrared spectroscopy to investigate the existence of radiation induced N-related defects in Si. Besides well-known signals of substitutional (Ns) at 653 cm−1, interstitial (Ni) at 691 cm−1, N2 at 766 cm−1, N–O complexes at 801, 996 and 1026 cm−1 and N2O at 973 and 996 cm−1 we determined some additional signals. The pair of bands at 646 and 663 cm−1 has been tentatively correlated with the Ns V pair in agreement with previous theoretical calculations. Similarly the pair of bands at 725 and 778 cm−1 has been tentatively correlated with the N2 V complex and another pair of bands at 930 and 953 cm−1 may be related with the N2SiI complex. Additionally, oxygen-vacancy defects such as the vacancy-oxygen pair (A-center or VO) are common in electron irradiated Si and can impact the material and electronic properties of Si. We investigate and compare the effect of N doping on oxygen-vacancy defects in electron irradiated Si. It is determined that nitrogen reduces the production of VO defects

Observation of the Decay Ds+→ωπ+D_{s}^{+}\to \omega\pi^{+}

Using e+e- annihilation data collected by the CLEO~II detector at CESR, we have observed the decay Ds+ to omega pi+. This final state may be produced through the annihilation decay of the Ds+, or through final state interactions. We find a branching ratio of [Gamma(Ds+ to omega pi+)/Gamma(Ds+ to eta pi+)]=0.16+-0.04+-0.03, where the first error is statistical and the second is systematic.Comment: 9 pages, postscript file also available through http://w4.lns.cornell.edu/public/CLN

Assessing the Value of DNA Barcodes and Other Priority Gene Regions for Molecular Phylogenetics of Lepidoptera

BACKGROUND: Despite apparently abundant amounts of observable variation and species diversity, the order Lepidoptera exhibits a morphological homogeneity that has provided only a limited number of taxonomic characters and led to widespread use of nucleotides for inferring relationships. This study aims to characterize and develop methods to quantify the value of priority gene regions designated for Lepidoptera molecular systematics. In particular, I assess how the DNA barcode segment of the mitochondrial COI gene performs across a broad temporal range given its number one position of priority, most sequenced status, and the conflicting opinions on its phylogenetic performance. METHODOLOGY/PRINCIPAL FINDINGS: Gene regions commonly sequenced for lepidoptera phylogenetics were scored using multiple measures across three categories: practicality, which includes universality of primers and sequence quality; phylogenetic utility; and phylogenetic signal. I found that alternative measures within a category often appeared correlated, but high scores in one category did not necessarily translate into high scores in another. The DNA barcode was easier to sequence than other genes, and had high scores for utility but low signal above the genus level. CONCLUSIONS/SIGNIFICANCE: Given limited financial resources and time constraints, careful selection of gene regions for molecular phylogenetics is crucial to avoid wasted effort producing partially informative data. This study introduces an approach to assessing the value of gene regions prior to the initiation of new studies and presents empirical results to help guide future selections

Zooplankton spine induces aversion in small fish predators

The spined cladoceran Bythotrephes cederstroemi is protected from small fish predators due to the difficulty small fish have in ingesting the spine. Juvenile yellow perch (Perca flavescens) 50–60 mm in length were offered Bythotrephes with alternative prey available in two experiments. First, perch were observed as they gained experience with Bythotrephes and developed aversion to the zooplankter. Perch initially attacked and captured Bythotrephes . However, they struggled to ingest the spined zooplankter, rejected and recaptured it many times, and finally ceased to attack it. Second, perch were offered Bythotrephes with varying portions of the spine removed to clarify the spine's role in inducing such behaviors. Perch showed greater preference to attack nospine and half-spine Bythotrephes , and were less likely to reject and more likely to ingest Bythotrephes with the spine removed. For small or young fish that forage on zooplankton in lakes where Bythotrephes is present, aversion is an efficient response to the conspicuous but unpalatable spined cladoceran. However, aversion allows Bythotrephes , also a predator on zooplankton, to more effectively compete with young fish without an increase in predation risk.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47794/1/442_2004_Article_BF00317591.pd

Troubled social background of male anabolic-androgenic steroid abusers in treatment

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the social background and current social situation of male abusers of anabolic-androgenic steroids (AAS).</p> <p>Methods</p> <p>We compared thirty-four AAS-abusing patients from an Addiction Centre (AC) with two groups, 18 users and 259 non-users of AAS from a public gym in Orebro, Sweden. The study is based on semi-structured interviews and questionnaires.</p> <p>Results</p> <p>Histories of a troubled childhood as well as current social disadvantage were both more frequent among the AAS users. Users also reported poor relationships with their parents and almost half of them had experienced physical or mental abuse. The AC group's experiences from school were mostly negative, and included concentration problems, boredom and learning difficulties. Their current circumstance included abuse of other drugs, battering of spouses and other criminality such as assault, illegal possession of weapons and theft.</p> <p>Conclusion</p> <p>In conclusion, this study shows that abusers of AAS often have a troubled social background. This underlines the importance of making a thorough social assessment as a part of the treatment programme. The results of the study may help in directing appropriate questions relevant to the abuse of AAS.</p