Distributions of flux vacua

We give results for the distribution and number of flux vacua of various types, supersymmetric and nonsupersymmetric, in IIb string theory compactified on Calabi-Yau manifolds. We compare this with related problems such as counting attractor points.Comment: 43 pages, 7 figures. v2: improved discussion of finding vacua with discrete flux, references adde

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. Interaction of bacterial dextran, platelets and fibrin (1978) J. Clin. Invest., 61, pp. 1394-1404Herzberg, M.C., Gong, K., McMarlane, G.D., Phenotypic characterization of Streptococcus sanguis virulence factors associated with bacterial endocarditis (1990) Infect. Immun., 58, pp. 515-522Cheung, A.L., Fischetti, V.A., The role of fibrinogen in staphylococcal adherence to catheters in vitro (1990) J. Infect. Dis., 161, pp. 1177-1186Herrmann, 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. 693-701Cheung, A.L., Projan, S.J., Cloning and sequencing of sarA: A gene required for the expression of agr (1994) J. Bacteriol., 176, pp. 4168-4172Scheld, W.M., Strunk, R.W., Balian, G., Calderone, R.A., Microbial adhesion to fibronectin in vitro correlates with production of endocarditis in rabbits (1985) Proc. Soc. Exp. Biol. Med., 180, pp. 474-482Durack, D.T., Beeson, P.B., Pathogenesis of infective endocarditis (1980) Infective Endocarditis, pp. 1-53. , S. H. Rahimtoola, editor. Grune and Stratton, Inc., New YorkJaffe, E., Cell biology of endothelial cells (1987) Hum. Pathol., 18, pp. 234-239Lopes, J.D., Reis, M.D., Bretani, R.R., Presence of laminin receptors in Staphylococcus aureus (1985) Science (Wash. DC), 229, pp. 275-277Patti, J.M., Bremell, T., Krajewska-Paetrasik, D., Adelnour, A., Tarkowski, A., Ryden, C., Höök, M., The Staphylococcus aureus collagen adhesin is a virulence determinant in experimental septic arthritis Infect. Immun., 62, pp. 152-161Herrmann, M., Suchard, S.J., Boxer, L.A., Waldvogel, F.A., Lew, P.D., Thrombospondin binds to Staphylococcus aureus and promotes staphylococcal adhesion to surfaces (1991) Infect. Immun., 59, pp. 279-288Bhakdi, S., Muhly, M., Mannhardt, U., Hugo, F., Klapettek, K., Muller-Eckhardt, C., Roka, L., Staphylococcal α-toxin promotes blood coagulation via attack on human platelets (1988) J. Exp. Med., 168, pp. 527-542Suttorp, N., Hessz, T., Seeger, W., Wilke, A., Koob, R., Lutz, F., Drenckhahn, D., Bacterial exotoxins and endothelial permeability for water and albumin in vitro (1988) Am. J. Physiol., 255, pp. C368Novick, R.P., Genetic systems in staphylococci (1991) Methods Enzymol., 204, pp. 587-636O'Reilly, M., De Azavedo, J.C.S., Kennedy, S., Foster, T.J., Inactivation of the alpha-hemolysin of Staphylococcus aureus 8325-4 by site directed mutagenesis and studies on the expression of its haemolysins (1986) Microb. Pathog., 1, pp. 125-138Projan, S.J., Kornblum, J., Kreiswirth, B., Moghazeh, S., Eisner, W., Novick, R.P., The β hemolysin gene of Staphylococcus aureus (1989) Nucleic Acids Res., 17, p. 3305Camilli, A., Portnoy, D.A., Youngman, P., Insertional mutagenesis of Listeria monocytogenes with a novel Tn917 derivative that allows direct cloning of DNA flanking transposon insertions (1990) J. Bacteriol., 172, pp. 3738-3744Nesin, M., Svec, P., Lupski, J.R., Godson, G.N., Kreiswirth, B., Kornblum, J., Projan, S.J., Cloning and nucleotide sequencing of a chromosomally encoded tetracycline resistance determinant, tetA(M), from a pathogenic, methicillin resistant strain of Staphylococcus aureus (1990) Antimicrob. Agents Chemother., 34, pp. 2273-227

D-Matter

We study the properties and phenomenology of particle-like states originating from D-branes whose spatial dimensions are all compactified. They are non-perturbative states in string theory and we refer to them as D-matter. In contrast to other non-perturbative objects such as 't Hooft-Polyakov monopoles, D-matter states could have perturbative couplings among themselves and with ordinary matter. The lightest D-particle (LDP) could be stable because it is the lightest state carrying certain (integer or discrete) quantum numbers. Depending on the string scale, they could be cold dark matter candidates with properties similar to that of wimps or wimpzillas. The spectrum of excited states of D-matter exhibits an interesting pattern which could be distinguished from that of Kaluza-Klein modes, winding states, and string resonances. We speculate about possible signatures of D-matter from ultra-high energy cosmic rays and colliders.Comment: 25 pages, 5 figures, references adde

Shapes of the Proton

A model proton wave function, constructed using Poincare invariance, and constrained by recent electromagnetic form factor data, is used to study the shape of the proton. Spin-dependent quark densities are defined as matrix elements of density operators in proton states of definite spin-polarization, and shown to have an infinite variety of non-spherical shapes. For high momentum quarks with spin parallel to that of the proton, the shape resembles that of a peanut, but for quarks with anti-parallel spin the shape is that of a bagel.Comment: 8 pages, 5 figures, to be submitted to Phys. Rev. C This corrects a few typos and explains some further connections with experiment

Somatosensory profiling of patients undergoing alcohol withdrawal: Do neuropathic pain and sensory loss represent a problem?

Chronic heavy alcohol use is known to cause neurological complications such as peripheral neuropathy. Concerning the pathophysiology, few sural nerve and skin biopsy studies showed that small fibers might be selectively vulnerable to degeneration in alcohol-related peripheral neuropathy. Pain has rarely been properly evaluated in this pathology. The present study aims at assessing pain intensity, potential neuropathic characteristics as well as the functionality of both small and large nerve sensitive fibers. In this observational study, 27 consecutive adult patients, hospitalized for alcohol withdrawal and 13 healthy controls were recruited. All the participants underwent a quantitative sensory testing (QST) according to the standardized protocol of the German Research Network Neuropathic Pain, a neurological examination and filled standardized questionnaires assessing alcohol consumption and dependence as well as pain characteristics and psychological comorbidities. Nearly half of the patients (13/27) reported pain. Yet, pain intensity was weak, leading to a low interference with daily life, and its characteristics did not support a neuropathic component. A functional impairment of small nerve fibers was frequently described, with thermal hypoesthesia observed in 52% of patients. Patients with a higher alcohol consumption over the last 2 years showed a greater impairment of small fiber function. Patients report pain but it is however unlikely to be caused by peripheral neuropathy given the non-length-dependent distribution and the absence of neuropathic pain features. Chronic pain in AUD deserves to be better evaluated and managed as it represents an opportunity to improve long-term clinical outcomes, potentially participating to relapse prevention

Tunneling and Metastability of continuous time Markov chains

We propose a new definition of metastability of Markov processes on countable state spaces. We obtain sufficient conditions for a sequence of processes to be metastable. In the reversible case these conditions are expressed in terms of the capacity and of the stationary measure of the metastable states

Exact Two-Point Correlation Functions of Turbulence Without Pressure in Three-Dimensions

We investigate exact results of isotropic turbulence in three-dimensions when the pressure gradient is negligible. We derive exact two-point correlation functions of density in three-dimensions and show that the density-density correlator behaves as $|{x_1 - x_2}|^{-\alpha_3}$, where $\alpha_3 = 2 + \frac{\sqrt{33}}{6}$. It is shown that, in three-dimensions, the energy spectrum $E(k)$ in the inertial range scales with exponent $2 - \frac {\sqrt{33}}{12} \simeq 1.5212$. We also discuss the time scale for which our exact results are valid for strong 3D--turbulence in the presence of the pressure. We confirm our predictions by using the recent results of numerical calculations and experiment.Comment: 9 pages, latex, no figures, we have corrected the our basic equations. We predict the inertial-range exponent for the energy spectrum for 3D-turbulence without pressure. We will present the detail of calculation and the results for 2D-turbulence elsewhere. Also some references are adde

Anisotropic effect on two-dimensional cellular automaton traffic flow with periodic and open boundaries

By the use of computer simulations we investigate, in the cellular automaton of two-dimensional traffic flow, the anisotropic effect of the probabilities of the change of the move directions of cars, from up to right ($p_{ur}$) and from right to up ($p_{ru}$), on the dynamical jamming transition and velocities under the periodic boundary conditions in one hand and the phase diagram under the open boundary conditions in the other hand. However, in the former case, the first order jamming transition disappears when the cars alter their directions of move ($p_{ur}\neq 0$ and/or $p_{ru}\neq 0$). In the open boundary conditions, it is found that the first order line transition between jamming and moving phases is curved. Hence, by increasing the anisotropy, the moving phase region expand as well as the contraction of the jamming phase one. Moreover, in the isotropic case, and when each car changes its direction of move every time steps ($p_{ru}=p_{ur}=1$), the transition from the jamming phase (or moving phase) to the maximal current one is of first order. Furthermore, the density profile decays, in the maximal current phase, with an exponent $\gamma \approx {1/4}$.}Comment: 13 pages, 22 figure