Black Hole Production at LHC: String Balls and Black Holes from pp and Lead-lead Collisions

If the fundamental planck scale is near a TeV, then parton collisions with high enough center-of-mass energy should produce black holes. The production rate for such black holes at LHC has been extensively studied for the case of a proton-proton collision. In this paper, we extend this analysis to a lead-lead collision at LHC. We find that the cross section for small black holes which may in principle be produced in such a collision is either enhanced or suppressed, depending upon the black hole mass. For example, for black holes with a mass around 3 TeV we find that the differential black hole production cross section, d\sigma/dM, in a typical lead-lead collision is up to 90 times larger than that for black holes produced in a typical proton-proton collision. We also discuss the cross-sections for `string ball' production in these collisions. For string balls of mass about 1 (2) TeV, we find that the differential production cross section in a typical lead-lead collision may be enhanced by a factor up to 3300 (850) times that of a proton-proton collision at LHC.Comment: Added some discussion, final version to appear in Phys. Rev. D (rapid communications

Diminished Virulence Of A Sar-lagr- Mutant Of Staphylococcus Aureus In The Rabbit Model Of Endocarditis

Microbial pathogenicity in Staphylococcus aureus is a complex process involving a number of virulence genes that are regulated by global regulatory systems including sar and agr. To evaluate the roles of these two loci in virulence, we constructed sar-lagr- mutants of strains RN6390 and RN450 and compared their phenotypic profiles to the corresponding single sar- and agr- mutants and parents. The secretion of all hemolysins was absent in the sar-lagr- mutants while residual β-hemolysin activity remained in single agr- mutants. The fibronectin binding capacity was significantly diminished in both single sar- mutants and double mutants when compared with parents while the reduction in fibrinogen binding capacity in the double mutants was modest. In the rabbit endocarditis model, there was a significant decrease in both infectivity rates and intravegetation bacterial densities with the double mutant as compared to the parent (RN6390) at 103-106 CFU inocula despite comparable levels of early bacteremia among various challenge groups. Notably, fewer bacteria in the double mutant group adhered to valvular vegetations at 30 min after challenge (106 CFU) than the parent group. These studies suggest that both the sar and agr loci are involved in initial valvular adherence, intravegetation persistence and multiplication of S. aureus in endocarditis.94518151822Waldvogel, F.A., Staphylococcus aureus (1985) Principles and Practice of Infectious Diseases, pp. 1097-1116. , G. L. Mandell, R. G. Douglas, Jr., and J. E. Bennett, editors. John Wiley & Sons, New YorkNeu, H.C., The crisis in antibiotic resistance (1992) Science (Wash. DC), 257, pp. 1064-1072Cohen, M.L., Epidemiology of drug resistance: Implications for a post-antibiotic era (1992) Science (Wash. DC), 257, pp. 1050-1055Easmon, C.S.F., Adlam, C., (1983) Staphylococci and Staphylococcal Infections, pp. 705-740. , Academic Press, New YorkCheung, A.L., Krishnan, M., Jaffe, E.A., Fischetti, V.A., Fibrinogen acts as a bridging molecule in the adherence of Staphylococcus aureus to cultured human endothelial cells (1991) J. Clin. Invest., 87, pp. 2236-2245Herrmann, M., Vaudaux, P.E., Pittet, D., Auckenthaler, R., Lew, P.D., Schumacher Perdreau, F., Peters, G., Waldvogel, F.A., Fibronectin, fibrinogen, and laminin act as mediators of adherence of clinical staphylococcal isolates to foreign material (1988) J. Infect. Dis., 158, pp. 693-701Kuypers, J.M., Proctor, R.A., Reduced adherence to traumatized rat heart valves by a low-fibronectin-binding mutant of Staphylococcus aureus (1989) Infect. Immun., 57, pp. 2306-2312DeRita, V.J., Mekalanos, J.J., Genetic regulation of bacterial virulence (1989) Annu. Rev. Genet., 23, pp. 455-482Kornblum, J., Kreiswirth, B., Projan, S.J., Ross, H., Novick, R.P., Agr: A polycistronic locus regulating exoprotein synthesis in Staphylococcus aureus (1990) Molecular Biology of the Staphylococci, pp. 373-402. , R. P. Novick, editor. VCH Publishers, New YorkNixon, B.T., Ronson, C.W., Ausubel, R.M., Two component regulatory systems responsive to environmental stimuli share strongly conserved domains with the nitrogen assimilation regulatory genes ntrB and btrC (1986) Proc. Natl. Acad. Sci. USA, 83, pp. 7850-7854Smeltzer, M.S., Hart, M.E., Iandolo, J.J., Phenotypic characterization of xpr, a global regulator of extracellular virulence factors in Staphylococcus aureus (1993) Infect. Immun., 61, pp. 919-925Cheung, A.L., Koomey, J.M., Butler, C.A., Projan, S.J., Fischetti, V.A., Regulation of exoprotein expression in Staphylococcus aureus by a locus (sar) distinct from agr (1992) Proc. Natl. Acad. Sci. USA, 89, pp. 6462-6466Cheung, A.L., Yeaman, M., Bayer, A.S., The role of the sar locus of Staphylococcus aureus in the induction of endocarditis in rabbits (1994) Infect. Immun., 62, pp. 1719-1725Vandenesch, F., Kornblum, J., Novick, R.P., A temporal signal, independent of agr, is required for hla but not spa transcription in Staphylococcus aureus (1991) J. Bacteriol., 173, pp. 6313-6320Cheung, A.L., Ying, P., Regulation of α and β hemolysins by the sar locus of Staphylococcus aureus (1994) J. Bacteriol., 176, pp. 580-585Rescei, P., Kreiswirth, B., O'Reilly, M., Schlievert, P., Gruss, A., Novick, R.P., Regulation of exoprotein gene expression in Staphylococcus aureus by agr (1986) Mol. & Gen. Genet., 202, pp. 58-61Fröman, G., Switalski, L., Speziale, P., Höök, M., Isolation and characterization of a fibronectin receptor from Staphylococcus aureus (1987) J. Biol. Chem., 262, pp. 6564-6571Lantz, M., Allen, R.D., Bounelis, P., Switalski, L.M., Höök, M., Bacteroides gingivalis and Bacteroides intermedius recognize different sites on human fibrinogen (1990) J. Bacteriol., 172, pp. 716-726Yeaman, M.R., Sullam, P.M., Dazin, P.F., Norman, D.C., Bayer, A.S., Characterization of Staphylococcus aureus-platelet binding by quantitative flow cytometric analysis (1992) J. Infect. Dis., 166, pp. 65-73Clawson, C.C., White, J.G., Herzberg, M.C., Platelet interaction with bacteria. VI. Contrasting the role of fibrinogen and fibronectin (1980) Am. J. Hematol., 9, pp. 43-53Yeaman, M.R., Norman, D.C., Bayer, A.S., Staphylococcus aureus susceptibility to thrombin-induced platelet microbicidal protein is independent of platelet adherence and aggregation in vitro (1992) Infect. Immun., 60, pp. 2368-2374Sullam, P.M., Payan, D.G., Dazin, P.F., Valone, F.H., Binding of viridans group streptococci to human platelets: A quantitative analysis (1990) Infect. Immun., 58, pp. 3802-3806Yeaman, M.R., Puentes, S.M., Norman, D.C., Bayer, A.S., Partial characterization and staphylocidal activity of thrombin-induced platelet microbicidal protein (1992) Infect. Immun., 60, pp. 1202-1209Kornblum, J., Projan, S.J., Moghazeh, S.L., Novick, R., A rapid method to quantitate non-labeled RNA species in bacterial cells (1988) Gene, 63, pp. 75-85Maniatis, T., Fritsch, E.F., Sambrook, J., (1989) Molecular Cloning, a Laboratory Manual, , Cold Spring Harbor Laboratory, Cold Spring Harbor, NYDurack, D.T., Beeson, P.B., Experimental bacterial endocarditis. I. Colonization of a sterile vegetation (1972) Br. J. Exp. Pathol., 53, pp. 44-49Scheld, W.M., Valone, J.A., Sande, M.A., Bacterial adherence in the pathogenesis of endocarditis. 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Cold Nuclear Matter Effects on Dijet Productions in Relativistic Heavy-ion Reactions at LHC

We investigate the cold nuclear matter(CNM) effects on dijet productions in high-energy nuclear collisions at LHC with the next-to-leading order perturbative QCD. The nuclear modifications for dijet angular distributions, dijet invariant mass spectra, dijet transverse momentum spectra and dijet momentum imbalance due to CNM effects are calculated by incorporating EPS, EKS, HKN and DS param-etrization sets of parton distributions in nucleus . It is found that dijet angular distributions and dijet momentum imbalance are insensitive to the initial-state CNM effects and thus provide optimal tools to study the final-state hot QGP effects such as jet quenching. On the other hand, the invariant mass spectra and the transverse momentum spectra of dijet are generally enhanced in a wide region of the invariant mass or transverse momentum due to CNM effects with a feature opposite to the expected suppression because of the final-state parton energy loss effect in the QGP. The difference of EPS, EKS, HKN and DS parametrization sets of nuclear parton distribution functions is appreciable for dijet invariant mass spectra and transverse momentum spectra at p+Pb collisions, and becomes more pronounced for those at Pb+Pb reactions.Comment: 10 pages, 11 figure

Supersymmetric effects in top quark decay into polarized W-boson

We investigate the one-loop supersymmetric QCD (SUSY-QCD) and electroweak (SUSY-EW) corrections to the top quark decay into a b-quark and a longitudinal or transverse W-boson. The corrections are presented in terms of the longitudinal ratio \Gamma(t-->W_L b)/\Gamma(t--> W b) and the transverse ratio \Gamma(t-->W_- b)/\Gamma(t--> W b). In most of the parameter space, both SUSY-QCD and SUSY-EW corrections to these ratios are found to be less than 1% in magnitude and they tend to have opposite signs. The corrections to the total width \Gamma(t-->W b) are also presented for comparison with the existing results in the literature. We find that our SUSY-EW corrections to the total width differ significantly from previous studies: the previous studies give a large correction of more than 10% in magnitude for a large part of the parameter space while our results reach only few percent at most.Comment: Version in PRD (explanation and refs added

Adjuvant selection for influenza and RSV prefusion subunit vaccines

Subunit vaccines exhibit favorable safety and immunogenicity profiles and can be designed to mimic native antigen structures. However, pairing with an appropriate adjuvant is imperative in order to elicit effective humoral and cellular immune responses. In this study, we aimed to determine an optimal adjuvant pairing with the prefusion form of influenza haemagglutinin (HA) or respiratory syncytial virus (RSV) fusion (F) subunit vaccines in BALB/c mice in order to inform future subunit vaccine adjuvant selection. We tested a panel of adjuvants, including aluminum hydroxide (alhydrogel), QS21, Addavax, Addavax with QS21 (AdQS21), and Army Liposome Formulation 55 with monophosphoryl lipid A and QS21 (ALF55). We found that all adjuvants elicited robust humoral responses in comparison to placebo, with the induction of potent neutralizing antibodies observed in all adjuvanted groups against influenza and in AdQS21, alhydrogel, and ALF55 against RSV. Upon HA vaccination, we observed that none of the adjuvants were able to significantly increase the frequency of CD4+ and CD8+ IFN-γ+ cells when compared to unadjuvanted antigen. The varying responses to antigens with each adjuvant highlights that those adjuvants most suited for pairing purposes can vary depending on the antigen used and/or the desired immune response. We therefore suggest that an adjuvant trial for different subunit vaccines in development would likely be necessary in preclinical studies.Ariel Isaacs, Zheyi Li, Stacey T. M. Cheung, Danushka K. Wijesundara, Christopher L. D. McMillan, Naphak Modhiran ...et al

Sexual violence against women and children in Chinese societies

This article provides a comprehensive overview of the reported patterns of sexual violence against women and children in China. It reviews the prevalence of and risk factors for various types of sexual violence and discusses community knowledge and perceptions of these violent acts. It also critically examines three major problems of sexual violence research in China. First, the diversity of findings and study methods reported by surveys and criminal reports reflects the problems in obtaining accurate figures on the scope of the problem. Second, precautions must be taken in reading studies on Chinese culture-specific risk factors for domestic violence. Third, the study of culture-specific factors should not focus solely on cultural factors in a vacuum but rather, should examine traditional culture in the context of modern societies and consensus international standards of human rights. Recommendations for future research are also discussed. © 2009 Sage Publications.postprin

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

Strangeness nuclear physics: a critical review on selected topics

Selected topics in strangeness nuclear physics are critically reviewed. This includes production, structure and weak decay of $\Lambda$--Hypernuclei, the $\bar K$ nuclear interaction and the possible existence of $\bar K$ bound states in nuclei. Perspectives for future studies on these issues are also outlined.Comment: 63 pages, 51 figures, accepted for publication on European Physical Journal

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC

Measurements of inclusive jet suppression in heavy ion collisions at the LHC provide direct sensitivity to the physics of jet quenching. In a sample of lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the anti-kt algorithm with values for the distance parameter that determines the nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp. Jet production is found to be suppressed by approximately a factor of two in the 10% most central collisions relative to peripheral collisions. Rcp varies smoothly with centrality as characterized by the number of participating nucleons. The observed suppression is only weakly dependent on jet radius and transverse momentum. These results provide the first direct measurement of inclusive jet suppression in heavy ion collisions and complement previous measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables, submitted to Physics Letters B. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02