221 research outputs found

    Elliptic Models, Type IIB Orientifolds and the Ads/CFT Correspondence

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    We analyze the large N supergravity descriptions of the class of type IIB models T-dual to elliptic type IIA brane configurations containing two orientifold 6-planes and up to two NS 5-branes. The T-dual IIB configurations contain N D3-branes in the background of an orientifold 7-plane and, in some models, a Z_2 orbifold and/or D7-branes, which give rise to four-dimensional N=2 (or N=4) gauge theories with at most two factors. We identify the chiral primary states of the supergravity theories, and match them to gauge invariant operators of the corresponding superconformal theories using Maldacena's duality.Comment: 44 pages (typo corrected

    Aspects of Type 0 String Theory

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    A construction of compact tachyon-free orientifolds of the non-supersymmetric Type 0B string theory is presented. Moreover, we study effective non-supersymmetric gauge theories arising on self-dual D3-branes in Type 0B orbifolds and orientifolds.Comment: 9 pages, LATEX; submitted to Proceedings of Strings '9

    Anomaly Free Non-Supersymmetric Large NN Gauge Theories from Orientifolds

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    We construct anomaly free non-supersymmetric large N gauge theories from orientifolds of Type IIB on C^3/G orbifolds. In particular, massless as well as tachyonic one-loop tadpoles are cancelled in these models. This is achieved by starting with N=1,2{\cal N}=1,2 supersymmetric orientifolds with well defined world-sheet description and including discrete torsion (which breaks supersymmetry) in the orbifold action. In this way we obtain non-trivial non-chiral as well as anomaly free chiral large N gauge theories. We point out certain subtleties arising in the chiral cases. Subject to certain assumptions, these theories are shown to have the property that computation of any M-point correlation function in these theories reduces to the corresponding computation in the parent N=4{\cal N}=4 oriented theory. This generalizes the analogous results recently obtained in supersymmetric large N gauge theories from orientifolds, as well as in (non)supersymmetric large N gauge theories without orientifold planes.Comment: 18 pages, revtex, minor misprints corrected, a clarifying footnote added (to appear in Phys. Rev. D

    World-sheet duality for D-branes with travelling waves

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    We study D-branes with plane waves of arbitrary profiles as examples of time-dependent backgrounds in string theory. We show how to reproduce the quantum mechanical (one-to-one) open-string S-matrix starting from the closed-string boundary state for the D-branes, thereby establishing the channel duality of this calculation. The required Wick rotation to a Lorentzian worldsheet singles out as 'prefered' time coordinate the open-string light-cone time.Comment: 17 pages, Latex file, uses JHEP3.cls, two figures. Added references and corrected two typo

    Safety Outcomes During Pediatric GH Therapy : Final Results From the Prospective GeNeSIS Observational Program

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    Altres ajuts: Financial Support: GeNeSIS was sponsored by Eli Lilly and Company (Indianapolis, IN). In compliance with the Uniform Requirements for Manuscripts, established by the International Committee of Medical Journal Editors, the sponsor of this study did not impose any impediment, directly or indirectly, on the publication of the study's results. Disclosure Summary: C.J.C. and N.J. are employees and stockholders ofEliLilly and Company (Indianapolis, IN).W.F.B. and A.G.Z. are former employees and are stockholders of Lilly. C.L.D., T.H., M.M., and R.G.R. are former members of the GeNeSIS International Advisory Board; S.L., J.P.S., A.R.-U., and M.P. have served as regional advisors. B.P. has consulted for Eli Lilly Italia SpA, and E.C. has received grant support from Lilly. W.F.B. also reports heis aconsultant forAmmonett Pharma,Lilly Germany, and Merck KGaA Darmstadt. C.L.D. also reports receipt of grants, consultancy honoraria, and speaker fees from Lilly,EMD Serono, and Sandoz; grants fromOpko Prolor, Pfizer, and Versatis; honoraria and speaker fees from Roche; honoraria from Pfizer; and speaker fees from Novo Nordisk. The remaining authors have nothing to disclose.Safety concerns have been raised regarding premature mortality, diabetes, neoplasia, and cerebrovascular disease in association with GH therapy. To assess incidence of key safety outcomes. Prospective, multinational, observational study (1999 to 2015). A total of 22,311 GH-treated children from 827 investigative sites in 30 countries. Children with growth disorders. GH treatment. Standardized mortality ratio (SMR) and standardized incidence ratio (SIR) with 95% CIs for mortality, diabetes, and primary cancer using general population registries. Predominant short stature diagnoses were GH deficiency (63%), idiopathic short stature (13%), and Turner syndrome (8%), with mean ± SD follow-up of 4.2 ± 3.2 years (∼92,000 person-years [PY]). Forty-two deaths occurred in patients with follow-up, with an SMR (95% CI) of 0.61 (0.44, 0.82); the SMR was elevated for patients with cancer-related organic GH deficiency [5.87 (3.21, 9.85)]. Based on 18 cases, type 2 diabetes mellitus (T2DM) risk was elevated [SIR: 3.77 (2.24, 5.96)], but 72% had risk factors. In patients without cancer history, 14 primary cancers were observed [SIR: 0.71 (0.39, 1.20)]. Second neoplasms occurred in 31 of 622 cancer survivors [5.0%; 10.7 (7.5, 15.2) cases/1000 PY] and intracranial tumor recurrences in 67 of 823 tumor survivors [8.1%; 16.9 (13.3, 21.5) cases/1000 PY]. All three hemorrhagic stroke cases had risk factors. GeNeSIS (Genetics and Neuroendocrinology of Short Stature International Study) data support the favorable safety profile of pediatric GH treatment. Overall risk of death or primary cancer was not elevated in GH-treated children, and no hemorrhagic strokes occurred in patients without risk factors. T2DM incidence was elevated compared with the general population, but most cases had diabetes risk factors. Safety of GH therapy was assessed in a pediatric observational study. Death and primary cancer rates were not higher than in the general population; T2DM rate was higher owing to risk factors

    Semi-supervised prediction of protein subcellular localization using abstraction augmented Markov models

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    <p>Abstract</p> <p>Background</p> <p>Determination of protein subcellular localization plays an important role in understanding protein function. Knowledge of the subcellular localization is also essential for genome annotation and drug discovery. Supervised machine learning methods for predicting the localization of a protein in a cell rely on the availability of large amounts of labeled data. However, because of the high cost and effort involved in labeling the data, the amount of labeled data is quite small compared to the amount of unlabeled data. Hence, there is a growing interest in developing <it>semi-supervised methods</it> for predicting protein subcellular localization from large amounts of unlabeled data together with small amounts of labeled data.</p> <p>Results</p> <p>In this paper, we present an Abstraction Augmented Markov Model (AAMM) based approach to semi-supervised protein subcellular localization prediction problem. We investigate the effectiveness of AAMMs in exploiting <it>unlabeled</it> data. We compare semi-supervised AAMMs with: (i) Markov models (MMs) (which do not take advantage of unlabeled data); (ii) an expectation maximization (EM); and (iii) a co-training based approaches to semi-supervised training of MMs (that make use of unlabeled data).</p> <p>Conclusions</p> <p>The results of our experiments on three protein subcellular localization data sets show that semi-supervised AAMMs: (i) can effectively exploit unlabeled data; (ii) are more accurate than both the MMs and the EM based semi-supervised MMs; and (iii) are comparable in performance, and in some cases outperform, the co-training based semi-supervised MMs.</p

    The CardioMetabolic Health Alliance Working Toward a New Care Model for the Metabolic Syndrome

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    AbstractThe Cardiometabolic Think Tank was convened on June 20, 2014, in Washington, DC, as a “call to action” activity focused on defining new patient care models and approaches to address contemporary issues of cardiometabolic risk and disease. Individual experts representing >20 professional organizations participated in this roundtable discussion. The Think Tank consensus was that the metabolic syndrome (MetS) is a complex pathophysiological state comprised of a cluster of clinically measured and typically unmeasured risk factors, is progressive in its course, and is associated with serious and extensive comorbidity, but tends to be clinically under-recognized. The ideal patient care model for MetS must accurately identify those at risk before MetS develops and must recognize subtypes and stages of MetS to more effectively direct prevention and therapies. This new MetS care model introduces both affirmed and emerging concepts that will require consensus development, validation, and optimization in the future

    Gene expression relationship between prostate cancer cells of Gleason 3, 4 and normal epithelial cells as revealed by cell type-specific transcriptomes

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    Background: Prostate cancer cells in primary tumors have been typed CD10(-)/CD13(-)/CD24(hi)/CD26(+)/CD38(lo)/CD44(-)/CD104(-). This CD phenotype suggests a lineage relationship between cancer cells and luminal cells. The Gleason grade of tumors is a descriptive of tumor glandular differentiation. Higher Gleason scores are associated with treatment failure. Methods: CD26(+) cancer cells were isolated from Gleason 3+3 (G3) and Gleason 4+4 (G4) tumors by cell sorting, and their gene expression or transcriptome was determined by Affymetrix DNA array analysis. Dataset analysis was used to determine gene expression similarities and differences between G3 and G4 as well as to prostate cancer cell lines and histologically normal prostate luminal cells. Results: The G3 and G4 transcriptomes were compared to those of prostatic cell types of non-cancer, which included luminal, basal, stromal fibromuscular, and endothelial. A principal components analysis of the various transcriptome datasets indicated a closer relationship between luminal and G3 than luminal and G4. Dataset comparison also showed that the cancer transcriptomes differed substantially from those of prostate cancer cell lines. Conclusions: Genes differentially expressed in cancer are potential biomarkers for cancer detection, and those differentially expressed between G3 and G4 are potential biomarkers for disease stratification given that G4 cancer is associated with poor outcomes. Differentially expressed genes likely contribute to the prostate cancer phenotype and constitute the signatures of these particular cancer cell types.National Institutes of Health (NIH)[CA111244]National Institutes of Health (NIH)[CA98699]National Institutes of Health (NIH)[CA85859]National Institutes of Health (NIH)[DK63630][P50-GMO-76547

    PIPS: Pathogenicity Island Prediction Software

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    The adaptability of pathogenic bacteria to hosts is influenced by the genomic plasticity of the bacteria, which can be increased by such mechanisms as horizontal gene transfer. Pathogenicity islands play a major role in this type of gene transfer because they are large, horizontally acquired regions that harbor clusters of virulence genes that mediate the adhesion, colonization, invasion, immune system evasion, and toxigenic properties of the acceptor organism. Currently, pathogenicity islands are mainly identified in silico based on various characteristic features: (1) deviations in codon usage, G+C content or dinucleotide frequency and (2) insertion sequences and/or tRNA genetic flanking regions together with transposase coding genes. Several computational techniques for identifying pathogenicity islands exist. However, most of these techniques are only directed at the detection of horizontally transferred genes and/or the absence of certain genomic regions of the pathogenic bacterium in closely related non-pathogenic species. Here, we present a novel software suite designed for the prediction of pathogenicity islands (pathogenicity island prediction software, or PIPS). In contrast to other existing tools, our approach is capable of utilizing multiple features for pathogenicity island detection in an integrative manner. We show that PIPS provides better accuracy than other available software packages. As an example, we used PIPS to study the veterinary pathogen Corynebacterium pseudotuberculosis, in which we identified seven putative pathogenicity islands

    Health risk behaviours among adolescents in the English-speaking Caribbean: a review

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    <p>Abstract</p> <p>Background</p> <p>The aim of this paper was to review and summarize research on prevalence of health risk behaviours, their outcomes as well as risk and protective factors among adolescents in the English-speaking Caribbean.</p> <p>Methods</p> <p>Searching of online databases and the World Wide Web as well as hand searching of the <it>West Indian Medical Journal </it>were conducted. Papers on research done on adolescents aged 10 – 19 years old and published during the period 1980 – 2005 were included.</p> <p>Results</p> <p>Ninety-five relevant papers were located. Five papers were published in the 1980s, 47 in the 1990s, and from 2000–2005, 43 papers. Health risk behaviours and outcomes were divided into seven themes. Prevalence data obtained for these, included lifetime prevalence of <b>substance use</b>: cigarettes-24% and marijuana-17%; <b>high risk sexual behaviour</b>: initiation of sexual activity ≤ 10 years old-19% and those having more than six partners-19%; <b>teenage pregnancy</b>: teens account for 15–20% of all pregnancies and one-fifth of these teens were in their second pregnancy; <b>Sexually-Transmitted Infections (STIs)</b>: population prevalence of gonorrhoea and/or chlamydia in 18–21 year-olds was 26%; <b>mental health</b>: severe depression in the adolescent age group was 9%, and attempted suicide-12%; <b>violence and juvenile delinquency</b>: carrying a weapon to school in the last 30 days-10% and almost always wanting to kill or injure someone-5%; <b>eating disorders and obesity</b>: overweight-11%, and obesity-7%. Many of the risk behaviours in adolescents were shown to be related to the adolescent's family of origin, home environment and parent-child relationships. Also, the protective effects of family and school connectedness as well as increased religiosity noted in studies from the United States were also applicable in the Caribbean.</p> <p>Conclusion</p> <p>There is a substantial body of literature on Caribbean adolescents documenting prevalence and correlates of health risk behaviours. Future research should emphasize the designing and testing of interventions to alleviate this burden.</p
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