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Sample records for aureus sigma b-dependent

  1. Identification of a sigma B-dependent small noncoding RNA in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Nielsen, Jesper Sejrup; Olsen, Anders Steno; Bonde, Mette; Valentin-Hansen, Poul; Kallipolitis, Birgitte H

    2008-01-01

    In Listeria monocytogenes, the alternative sigma factor sigma(B) plays important roles in stress tolerance and virulence. Here, we present the identification of SbrA, a novel small noncoding RNA that is produced in a sigma(B)-dependent manner. This finding adds the sigma(B) regulon to the growing...

  2. Alternative sigma factor sigmaH modulates prophage integration and excision in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Liang Tao

    2010-05-01

    Full Text Available The prophage is one of the most important components of variable regions in bacterial genomes. Some prophages carry additional genes that may enhance the toxicity and survival ability of their host bacteria. This phenomenon is predominant in Staphylococcus aureus, a very common human pathogen. Bioinformatics analysis of several staphylococcal prophages revealed a highly conserved 40-bp untranslated region upstream of the int gene. A small transcript encoding phage integrase was identified to be initiated from the region, demonstrating that the untranslated region contained a promoter for int. No typical recognition sequence for either sigma(A or sigma(B was identified in the 40-bp region. Experiments both in vitro and in vivo demonstrated that sigma(H recognized the promoter and directed transcription. Genetic deletion of sigH altered the int expression, and subsequently, the excision proportion of prophage DNAs. Phage assays further showed that sigH affected the ability of spontaneous lysis and lysogenization in S. aureus, suggesting that sigH plays a role in stabilizing the lysogenic state. These findings revealed a novel mechanism of prophage integration specifically regulated by a host-source alternative sigma factor. This mechanism suggests a co-evolution strategy of staphylococcal prophages and their host bacteria.

  3. IsdB-dependent Hemoglobin Binding Is Required for Acquisition of Heme by Staphylococcus aureus

    OpenAIRE

    Pishchany, Gleb; Sheldon, Jessica R.; Dickson, Claire F.; Alam, Md Tauqeer; Read, Timothy D.; Gell, David A; Heinrichs, David E.; Skaar, Eric P.

    2013-01-01

    Staphylococcus aureus is a Gram-positive pathogen responsible for tremendous morbidity and mortality. As with most bacteria, S. aureus requires iron to cause disease, and it can acquire iron from host hemoglobin. The current model for staphylococcal hemoglobin-iron acquisition proposes that S. aureus binds hemoglobin through the surface-exposed hemoglobin receptor IsdB. IsdB removes heme from bound hemoglobin and transfers this cofactor to other proteins of the Isd system, which import and de...

  4. Induction of Fibronectin Adhesins in Quinolone-Resistant Staphylococcus aureus by Subinhibitory Levels of Ciprofloxacin or by Sigma B Transcription Factor Activity Is Mediated by Two Separate Pathways

    Science.gov (United States)

    Li, Dongmei; Renzoni, Adriana; Estoppey, Tristan; Bisognano, Carmelo; Francois, Patrice; Kelley, William L.; Lew, Daniel P.; Schrenzel, Jacques; Vaudaux, Pierre

    2005-01-01

    We recently reported on the involvement of a RecA-LexA-dependent pathway in the ciprofloxacin-triggered upregulation of fibronectin-binding proteins (FnBPs) by fluoroquinolone-resistant Staphylococcus aureus. The potential additional contribution of the transcription factor sigma B (SigB) to the ciprofloxacin-triggered upregulation of FnBPs was studied in isogenic mutants of fluoroquinolone-resistant strain RA1 (a topoisomerase IV gyrase double mutant of S. aureus NCTC strain 8325), which exhibited widely different levels of SigB activity, as assessed by quantitative reverse transcription-PCR of their respective sigB and SigB-dependent asp23 transcript levels. These mutants were Tn551 insertion sigB strain TE1 and rsbU+ complemented strain TE2, which exhibited a wild-type SigB operon. Levels of FnBP surface display and fibronectin-mediated adhesion were lower in sigB mutant TE1 or higher in the rsbU+-restored strain TE2 compared to their sigB+ but rsbU parent, strain RA1, exhibiting low levels of SigB activity. Steady-state fnbA and fnbB transcripts levels were similar in strains TE1 and RA1 but increased by 4- and 12-fold, respectively, in strain TE2 compared to those in strain RA1. In contrast, fibronectin-mediated adhesion of strains TE1, RA1, and TE2 was similarly enhanced by growth in the presence of one-eighth the MIC of ciprofloxacin, which led to a significantly higher increase in their fnbB transcript levels compared to the increase in their fnbA transcript levels. Increased SigB levels led to a significant reduction in agr RNAIII; in contrast, it led to a slight increase in sarA transcript levels. In conclusion, upregulation of FnBPs by increased SigB levels and ciprofloxacin exposure in fluoroquinolone-resistant S. aureus occurs via independent pathways whose concerted actions may significantly promote bacterial adhesion and colonization. PMID:15728884

  5. Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections.

    Directory of Open Access Journals (Sweden)

    Lorena Tuchscherr

    2015-04-01

    Full Text Available Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs, which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, ΔsigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy

  6. Induction of Fibronectin Adhesins in Quinolone-Resistant Staphylococcus aureus by Subinhibitory Levels of Ciprofloxacin or by Sigma B Transcription Factor Activity Is Mediated by Two Separate Pathways

    OpenAIRE

    Li, Dongmei; Renzoni, Adriana; Estoppey, Tristan; Bisognano, Carmelo; Francois, Patrice; Kelley, William L; Lew, Daniel P.; Schrenzel, Jacques; Vaudaux, Pierre

    2005-01-01

    We recently reported on the involvement of a RecA-LexA-dependent pathway in the ciprofloxacin-triggered upregulation of fibronectin-binding proteins (FnBPs) by fluoroquinolone-resistant Staphylococcus aureus. The potential additional contribution of the transcription factor sigma B (SigB) to the ciprofloxacin-triggered upregulation of FnBPs was studied in isogenic mutants of fluoroquinolone-resistant strain RA1 (a topoisomerase IV gyrase double mutant of S. aureus NCTC strain 8325), which exh...

  7. The extracytoplasmic function sigma factor σS protects against both intracellular and extracytoplasmic stresses in Staphylococcus aureus.

    Science.gov (United States)

    Miller, Halie K; Carroll, Ronan K; Burda, Whittney N; Krute, Christina N; Davenport, Jessica E; Shaw, Lindsey N

    2012-08-01

    Previously we identified a novel component of the Staphylococcus aureus regulatory network, an extracytoplasmic function σ-factor, σ(S), involved in stress response and disease causation. Here we present additional characterization of σ(S), demonstrating a role for it in protection against DNA damage, cell wall disruption, and interaction with components of the innate immune system. Promoter mapping reveals the existence of three unique sigS start sites, one of which appears to be subject to autoregulation. Transcriptional profiling revealed that sigS expression remains low in a number of S. aureus wild types but is upregulated in the highly mutated strain RN4220. Further analysis demonstrates that sigS expression is inducible upon exposure to a variety of chemical stressors that elicit DNA damage, including methyl methanesulfonate and ciprofloxacin, as well as those that disrupt cell wall stability, such as ampicillin and oxacillin. Significantly, expression of sigS is highly induced during growth in serum and upon phagocytosis by RAW 264.7 murine macrophage-like cells. Phenotypically, σ(S) mutants display sensitivity to a broad range of DNA-damaging agents and cell wall-targeting antibiotics. Furthermore, the survivability of σ(S) mutants is strongly impacted during challenge by components of the innate immune system. Collectively, our data suggest that σ(S) likely serves dual functions within the S. aureus cell, protecting against both cytoplasmic and extracytoplasmic stresses. This further argues for its important, and perhaps novel, role in the S. aureus stress and virulence responses. PMID:22685284

  8. Staphylococcus aureus Transcriptome Architecture

    DEFF Research Database (Denmark)

    Mäder, Ulrike; Nicolas, Pierre; Depke, Maren;

    2016-01-01

    Staphylococcus aureus is a major pathogen that colonizes about 20% of the human population. Intriguingly, this Gram-positive bacterium can survive and thrive under a wide range of different conditions, both inside and outside the human body. Here, we investigated the transcriptional adaptation of S...... to their dependence on the RNA polymerase sigma factors SigA or SigB, and allow identification of new potential targets for several known transcription factors. In particular, this study revealed a relatively low abundance of antisense RNAs in S. aureus, where they overlap only 6% of the coding genes, and only 19...... antisense RNAs not co-transcribed with other genes were found. Promoter analysis and comparison with Bacillus subtilis links the small number of antisense RNAs to a less profound impact of alternative sigma factors in S. aureus. Furthermore, we revealed that Rho-dependent transcription termination...

  9. 6 sigma quality performance

    International Nuclear Information System (INIS)

    This deals with 6 sigma quality performance introducing company which has 6 sigma quality management, 6 sigma quality activity and customer, secret of success of 6 sigma quality management, what 6 sigma is, 6 sigma quality management propel system 5 propel steps of project like point of 6 sigma, flow of problem solution, tool for propel of project, performance of CTQ and total customer satisfaction, and quality management system and 6 sigma quality.

  10. A non-coding RNA promotes bacterial persistence and decreases virulence by regulating a regulator in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Cédric Romilly

    2014-03-01

    Full Text Available Staphylococcus aureus produces a high number of RNAs for which the functions are poorly understood. Several non-coding RNAs carry a C-rich sequence suggesting that they regulate mRNAs at the post-transcriptional level. We demonstrate that the Sigma B-dependent RsaA RNA represses the synthesis of the global transcriptional regulator MgrA by forming an imperfect duplex with the Shine and Dalgarno sequence and a loop-loop interaction within the coding region of the target mRNA. These two recognition sites are required for translation repression. Consequently, RsaA causes enhanced production of biofilm and a decreased synthesis of capsule formation in several strain backgrounds. These phenotypes led to a decreased protection of S. aureus against opsonophagocytic killing by polymorphonuclear leukocytes compared to the mutant strains lacking RsaA. Mice animal models showed that RsaA attenuates the severity of acute systemic infections and enhances chronic catheter infection. RsaA takes part in a regulatory network that contributes to the complex interactions of S. aureus with the host immune system to moderate invasiveness and favour chronic infections. It is the first example of a conserved small RNA in S. aureus functioning as a virulence suppressor of acute infections. Because S. aureus is essentially a human commensal, we propose that RsaA has been positively selected through evolution to support commensalism and saprophytic interactions with the host.

  11. $I_{sigma}$-Convergence

    OpenAIRE

    Nuray, Fatih; Gök, Hafize; ULUSU, Uğur

    2011-01-01

    In this paper, the concepts of $sigma$-uniform density of subsets A of the set $mathbb{N}$ of positive integers and corresponding $I_{sigma}$-convergence were introduced. Furthermore, inclusion relations between $I_{sigma}$-convergence and invariant convergence also $I_{sigma}$-convergence and $[V_{sigma}]_{p}$-convergence were given.

  12. The point of 6 sigma

    International Nuclear Information System (INIS)

    This book gives descriptions of the point of 6 sigma. These are the titles of this : what 6 sigma is, sigma conception, motor roller 3.4 ppm, centering error, 6 sigma purpose, 6 sigma principle, eight steps of innovation strategy, 6 sigma innovation strategy of easy system step, measurement standard of 6 sigma outcome, the main role of 6 sigma, acknowledgment and reword, 6 sigma characteristic, 6 sigma effect, 6 sigma application and problems which happen when 6 sigma introduces.

  13. What is Six Sigma ?

    Directory of Open Access Journals (Sweden)

    Prof. Ph.D. Sorin-George Toma

    2008-12-01

    Full Text Available Over the past decades, several business improvement methods were launched, includingthe one known as Six Sigma. The Six Sigma implies the application of scientific principles to business processesand allows companies to obtain better, faster and cheaper products and services. Motorola was thefirst company that introduced and implemented Six Sigma in its business processes in the 1980s.

  14. What is Six Sigma ?

    OpenAIRE

    Prof. Ph.D. Sorin-George Toma

    2008-01-01

    Over the past decades, several business improvement methods were launched, including the one known as Six Sigma. The Six Sigma implies the application of scientific principles to business processes and allows companies to obtain better, faster and cheaper products and services. Motorola was the first company that introduced and implemented Six Sigma in its business processes in the 1980s.

  15. Supersymmetric nonlinear sigma models

    International Nuclear Information System (INIS)

    Supersymmetric nonlinear sigma models are formulated as gauge theories. Auxiliary chiral superfields are introduced to impose supersymmetric constraints of F-type. Target manifolds defined by F-type constraints are always non-compact. In order to obtain nonlinear sigma models on compact manifolds, we have to introduce gauge symmetry to eliminate the degrees of freedom in non-compact directions. All supersymmetric nonlinear sigma models defined on the hermitian symmetric spaces are successfully formulated as gauge theories. (author)

  16. SIGMA without effort

    International Nuclear Information System (INIS)

    SIGMA (System for Interactive Graphical Analysis) is an interactive computing language with automatic array handling and graphical facilities. It is designed as a tool for mathematical problem solving. The SIGMA language is simple, almost obvious, yet flexible and powerful. This tutorial introduces the beginner to SIGMA. It is supposed to be used at a graphics terminal having access to SIGMA. The user will learn the language in dialogue with the system in sixteen sessions of about one hour. The first session enables him already to compute and display functions of one or two variables. (Auth.)

  17. Six Sigma software development

    CERN Document Server

    Tayntor, Christine B

    2002-01-01

    Since Six Sigma has had marked success in improving quality in other settings, and since the quality of software remains poor, it seems a natural evolution to apply the concepts and tools of Six Sigma to system development and the IT department. Until now however, there were no books available that applied these concepts to the system development process. Six Sigma Software Development fills this void and illustrates how Six Sigma concepts can be applied to all aspects of the evolving system development process. It includes the traditional waterfall model and in the support of legacy systems,

  18. What is Six Sigma?

    Directory of Open Access Journals (Sweden)

    Gulcin Daglioglu

    2009-04-01

    Full Text Available Sigma (σ refers to Standard Deviation which is a measure of variation in statistics. Methodology of Six Sigma is a management philosophy that is based on the theory that parameters can be cotrolled. Six Sigma applications follow the process of identifying and defining defects, analyzing the defects using various measures, suggesting improvements and having metrics or controls in place to achieve the goals of the business. The error rate is defined as the number of error in a million. An increase in Sigma means decrease in the number of error, and lower values of Sigma correspond to higher number of error. The Six Sigma philosophy aims to bring about improvements in processes that have zero error. The Six Sigma approach is to implement methodologies that aim at reaching world standard quality which is 6 Sigma or more. The Six Sigma methodology used in clinical laboratories appears to be a quality management tool involving statistical calculations, process parameter based, and reports about the process performance. [Archives Medical Review Journal 2009; 18(2.000: 132-139

  19. Quantum Group $\\sigma$ Models

    CERN Document Server

    Frishman, Yitzhak; Zakrzewski, W J

    1993-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ are realised as $2N\\times 2N$ unitary matrices. Open problems are pointed out.

  20. Quantum Group $\\sigma$ Models

    OpenAIRE

    Frishman, Y.; Lukierski, J.; Zakrzewski, W. J.

    1992-01-01

    Field-theoretic models for fields taking values in quantum groups are investigated. First we consider $SU_q(2)$ $\\sigma$ model ($q$ real) expressed in terms of basic notions of noncommutative differential geometry. We discuss the case in which the $\\sigma$ models fields are represented as products of conventional $\\sigma$ fields and of the coordinate-independent algebra. An explicit example is provided by the $U_q(2)$ $\\sigma$ model with $q\\sp{N}=1$, in which case quantum matrices $U_q(2)$ ar...

  1. The b-dependence of structure functions in nuclei

    International Nuclear Information System (INIS)

    On the premise that shadowing and antishadowing in deep inelastic scattering in nuclei are partonic phenomena, we investigate the b-dependence of quark distributions in a nuclear environment. Utilising a model which gives a good global description both of deep inelastic scattering on nuclei and of Drell-Yan production in hadron nucleus collisions we show that there is a strong b-dependence of the structure functions. This is of considerable significance for understanding J/Ψ suppression relative to the Drell-Yan background in nucleus-nucleus collisions. (orig.)

  2. $\\sigma $ -Approximately Contractible Banach Algebras

    OpenAIRE

    Momeni, M; Yazdanpanah, T.; Mardanbeigi, M. R.

    2012-01-01

    We investigate $\\sigma $ -approximate contractibility and $\\sigma $ -approximate amenability of Banach algebras, which are extensions of usual notions of contractibility and amenability, respectively, where $\\sigma $ is a dense range or an idempotent bounded endomorphism of the corresponding Banach algebra.

  3. Supersymmetric sigma models

    International Nuclear Information System (INIS)

    We begin to construct the most general supersymmetric Lagrangians in one, two and four dimensions. We find that the matter couplings have a natural interpretation in the language of the nonlinear sigma model

  4. 6 Sigma project advance

    International Nuclear Information System (INIS)

    This book deals with 6 sigma project advance which introduces 6 sigma project in Changwon special steel, how is failure accepted? CTQ selection which is starting line, definition of performance standard, measurement system check on reliability of measurement data, check of process capacity for current level, establishment of target, optimal design and performance of application, practice of management system for maintain of improved result, CTQ selection, check of measurement system and practice of management system.

  5. Role of the alternative sigma factors sigmaE and sigmaS in survival of Salmonella enterica serovar Typhimurium during starvation, refrigeration and osmotic shock.

    Science.gov (United States)

    McMeechan, Alisdair; Roberts, Mark; Cogan, Tristan A; Jørgensen, Frieda; Stevenson, Andrew; Lewis, Claire; Rowley, Gary; Humphrey, Tom J

    2007-01-01

    The ability of Salmonella enterica serovar Typhimurium to survive environmental stress requires specific, coordinated, responses, which induce resistance to the stress condition. This study investigated the relative contribution of sigmaE and sigmaS, the sigma factors regulating extracytoplasmic and general stress response functions, respectively, to survival at low temperature and also in media of differing osmotic strength, conditions relevant to food preservation. To determine if low-temperature storage is a signal for sigmaE- and sigmaS-mediated survival, the ability of S. Typhimurium rpoE, rpoS and rpoE/rpoS mutants to survive in a saline starvation-survival model at a refrigeration temperature (4.5 degrees C) was examined. Under these conditions, the rpoE mutant was significantly (Psigma factors were important for maximum survival but sigmaS played the dominant role. Analysis of the metabolic activity of starved populations at 4.5 and 37 degrees C revealed significantly (PsigmaE- and sigmaS-regulated genes in maintaining energy homeostasis. Together these data demonstrate that sigmaE and sigmaS are important for survival of S. Typhimurium in conditions encountered during food processing and that the relative contribution of sigmaE and sigmaS is critically dependent on the precise nature of the stress. PMID:17185555

  6. Sigma models on supercosets

    Energy Technology Data Exchange (ETDEWEB)

    Mitev, Vladimir

    2010-08-15

    The purpose of this thesis is to deepen our understanding of the fundamental properties and defining features of non-linear sigma models on superspaces. We begin by presenting the major concepts that we have used in our investigation, namely Lie superalgebras and supergroups, non-linear sigma models and two dimensional conformal field theory. We then exhibit a method, called cohomological reduction, that makes use of the target space supersymmetry of non-linear sigma models to compute certain correlation functions. We then show how the target space supersymmetry of Ricci flat Lie supergroups simplifies the perturbation theory of suitable deformed Wess-Zumino-Witten models, making it possible to compute boundary conformal weights to all orders. This is then applied to the OSP (2S+2 vertical stroke 2S) Gross-Neveu Model, leading to a dual description in terms of the sigma model on the supersphere S{sup 2S+1} {sup vertical} {sup stroke} {sup 2S}. With this results in mind, we then turn to the similar, yet more intricate, theory of the non-linear sigma model on the complex projective superspaces CP{sup N-1} {sup vertical} {sup stroke} {sup N}. The cohomological reduction allows us to compute several important quantities non-perturbatively with the help of the system of symplectic fermions. Combining this with partial perturbative results for the whole theory, together with numerical computations, we propose a conjecture for the exact evolution of boundary conformal weights for symmetry preserving boundary conditions. (orig.)

  7. Sigma models on supercosets

    International Nuclear Information System (INIS)

    The purpose of this thesis is to deepen our understanding of the fundamental properties and defining features of non-linear sigma models on superspaces. We begin by presenting the major concepts that we have used in our investigation, namely Lie superalgebras and supergroups, non-linear sigma models and two dimensional conformal field theory. We then exhibit a method, called cohomological reduction, that makes use of the target space supersymmetry of non-linear sigma models to compute certain correlation functions. We then show how the target space supersymmetry of Ricci flat Lie supergroups simplifies the perturbation theory of suitable deformed Wess-Zumino-Witten models, making it possible to compute boundary conformal weights to all orders. This is then applied to the OSP (2S+2 vertical stroke 2S) Gross-Neveu Model, leading to a dual description in terms of the sigma model on the supersphere S2S+1verticalstroke2S. With this results in mind, we then turn to the similar, yet more intricate, theory of the non-linear sigma model on the complex projective superspaces CPN-1verticalstrokeN. The cohomological reduction allows us to compute several important quantities non-perturbatively with the help of the system of symplectic fermions. Combining this with partial perturbative results for the whole theory, together with numerical computations, we propose a conjecture for the exact evolution of boundary conformal weights for symmetry preserving boundary conditions. (orig.)

  8. Delta-Sigma Beamforming

    OpenAIRE

    2005-01-01

    Systems where data is collected using arrays of sensors will usually contain a beamformer. When the number of active channels in the sensor array is large, as it often is in imaging systems like sonar and medical ultrasound, the beamformer can be both physically large and expensive. To counteract one or both of these unwanted effects, several compact beamforming solutions have been suggested. Delta-sigma based beamforming is one such technique, where 1-bit delta-sigma A/D converters are used ...

  9. Inclusive $\\Sigma^{+}$ and $\\Sigma^{0}$ Production in Hadronic Z Decays

    CERN Document Server

    Acciarri, M; Adriani, O; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, L; Balandras, A; Banerjee, S; Banerjee, Sw; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brigljevic, V; Brochu, F; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; Cozzoni, B; de la Cruz, B; Csilling, Akos; Cucciarelli, S; Dai, T S; van Dalen, J A; D'Alessandro, R; De Asmundis, R; Déglon, P L; Degré, A; Deiters, K; Della Volpe, D; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Duchesneau, D; Dufournaud, D; Duinker, P; Durán, I; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Extermann, Pierre; Fabre, M; Faccini, R; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gau, S S; Gentile, S; Gheordanescu, N; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hidas, P; Hirschfelder, J; Hofer, H; Holzner, G; Hoorani, H; Hou, S R; Hu, Y; Iashvili, I; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Khan, R A; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, J K; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Koutsenko, V F; Kräber, M H; Krämer, R W; Krenz, W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lassila-Perini, K M; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Likhoded, S A; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Lugnier, L; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Marchesini, P A; Marian, G; Martin, J P; Marzano, F; Massaro, G G G; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Molnár, P; Monteleoni, B; Moulik, T; Muanza, G S; Muheim, F; Muijs, A J M; Musy, M; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nisati, A; Nowak, H; Organtini, G; Oulianov, A; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Paramatti, R; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Pothier, J; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Raspereza, A V; Raven, G; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schopper, Herwig Franz; Schotanus, D J; Schwering, G; Sciacca, C; Sciarrino, D; Seganti, A; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, A; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Suter, H; Swain, J D; Szillási, Z; Sztaricskai, T; Tang, X W; Tauscher, Ludwig; Taylor, L; Tellili, B; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Uchida, Y; Ulbricht, J; Valente, E; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, M; Wang, X L; Wang, Z M; Weber, A; Weber, M; Wienemann, P; Wilkens, H; Wu, S X; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Ye, J B; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhu, G Y; Zhu, R Y; Zichichi, A; Zilizi, G; Zöller, M

    2000-01-01

    We report on measurements of the inclusive production rate of $\\Sigma^+$ and $\\Sigma^0$ baryons in hadronic Z decays collected with the L3 detector at LEP. The $\\Sigma^+$ baryons are detected through the decay $\\Sigma^+ \\rightarrow {\\rm p} \\pi^0$, while the $\\Sigma^0$ baryons are detected via the decay mode $\\Sigma^0 \\rightarrow \\Lambda \\gamma$. The average numbers of $\\Sigma^+$ and $\\Sigma^0$ per hadronic Z decay are measured to be: \\begin{eqnarray*} \\left + \\left & = & 0.114 \\pm 0.011_{\\mbox{\\it \\small stat}} \\pm 0.009_{\\mbox{\\it \\small syst}} \\\\ \\left + \\left & = & 0.095 \\pm 0.015_{\\mbox{\\it \\small stat}} \\pm 0.013_{\\mbox{\\it \\small syst}} \\ \\mbox{.} \\end{eqnarray*} These rates are found to be higher than the predictions from Monte Carlo hadronization models and analytical parameterizations of strange baryon production.

  10. Six Sigma and Implementations of Six Sigma in Finance Sector

    OpenAIRE

    Gokhan Senol; Adem Anbar

    2010-01-01

    Quality is a one of the critical factors for achieving competitive advantage. Six sigma approach is a business strategy which usage has increased gradually in last years for quality improvement initiative. Although six sigma established by a manufacturing firm and it has been successfully implemented in many manufacturing firms, service firms have began to use six sigma for reducing cost, enhanced quality of service, increasing customer satisfaction and profitability. In this paper, six sigma...

  11. Generalized supersymmetry and sigma models

    International Nuclear Information System (INIS)

    In this paper, we discuss the generalizations of exact supersymmetries present in the supersymmetrized sigma models. These generalizations are made by making the supersymmetric transformation parameter field-dependent. Remarkably, the supersymmetric effective actions emerge naturally through the Jacobian associated with the generalized supersymmetry transformations. We explicitly demonstrate these for two different supersymmetric sigma models, namely, one-dimensional sigma model and topological sigma model for hyperinstantons on quaternionic manifold

  12. Six Sigma and Implementations of Six Sigma in Finance Sector

    Directory of Open Access Journals (Sweden)

    Gokhan Senol

    2010-04-01

    Full Text Available Quality is a one of the critical factors for achieving competitive advantage. Six sigma approach is a business strategy which usage has increased gradually in last years for quality improvement initiative. Although six sigma established by a manufacturing firm and it has been successfully implemented in many manufacturing firms, service firms have began to use six sigma for reducing cost, enhanced quality of service, increasing customer satisfaction and profitability. In this paper, six sigma was examined in a view of finance sector and applications of six sigma within the finance sector were evaluated.

  13. SIGMA Experimental Facility

    International Nuclear Information System (INIS)

    The SIGMA ( Separacion Isotopica Gaseosa por Metodos Avanzados) concept is outlined.The old gaseous diffusion process to enrich uranium has been updated to be economically competitive for small production volumes.Major innovations have been introduced in the membrane design and in the integrated design of compressors and diffusers.The use of injectors and gas turbines has been also adopted.The paper describes the demonstration facility installed by the Argentine Atomic Energy Commission

  14. DESIGN FOR SIX SIGMA

    Directory of Open Access Journals (Sweden)

    Liem Ferryanto

    2007-01-01

    Full Text Available This article provides a step by step process of executing analytical or computer based Design for Six Sigma using a Sliding Door project as an example. It comprises of identification of Voice Of the Customer (VOC, transformation of VOC to what it is called Critical To Quality characteristics (CTQs, modeling of system transfers function, optimal and robust solutions, and tolerance design approach

  15. Hyperosmotic shock induces the sigma32 and sigmaE stress regulons of Escherichia coli.

    Science.gov (United States)

    Bianchi, A A; Baneyx, F

    1999-12-01

    The rise in the levels of sigmaS that accompanies hyperosmotic shock plays an important role in Escherichia coli survival by increasing the transcription of genes involved in the synthesis and transport of osmoprotectants. To determine if other stress regulons collaborate with sigmaS in dealing with high osmolality, we used single copy fusions of lacZ to representative promoters induced by protein misfolding in the cytoplasm (dnaK and ibp ), extracytoplasmic stress [P3rpoH and htrA(degP )] and cold shock (cspA). Both the sigma32-dependent, dnaK and ibp, promoters, and the sigmaE-dependent, P3rpoH and htrA, promoters were rapidly but transiently induced when mid-exponential phase cells were treated with 0.464 M sucrose. The cspA promoter, however, did not respond to the same treatment. Overproduction of the cytoplasmic domain of the sigmaE anti-sigma factor, RseA, reduced the magnitude of osmotic induction in lambdaphi(P3rpoH:lacZ ) lysogens, but had no effect on the activation of the dnaK and ibp promoters. Similarly, induction of the dnaK:lacZ and ibp:lacZ fusions was not altered in either rpoS or ompR genetic backgrounds. Osmotic upshift led to a twofold increase in the enzymatic activity of the lambdaTLF247 rpoH:lacZ translational fusion whether or not the cells were treated with rifampicin, indicating that both heat shock and exposure to high osmolality trigger a transient increase in rpoH translation. Our results suggest that the sigma32, sigmaE and sigmaS regulons closely co-operate in the managment of hyperosmotic stress. Induction of the sigma32 and sigmaE regulons appears to be an emergency response required to repair protein misfolding and facilitate the proper folding of proteins that are rapidly synthesized following loss of turgor, while providing a mechanism to increase the activity of sigmaS, the primary stress factor in osmoadaptation. PMID:10594827

  16. Sigma-model aether

    OpenAIRE

    Carroll, Sean M.; Dulaney, Timothy R.; Gresham, Moira I.; Tam, Heywood

    2009-01-01

    Theories of low-energy Lorentz violation by a fixed-norm "aether" vector field with two-derivative kinetic terms have a globally bounded Hamiltonian and are perturbatively stable only if the vector is timelike and the kinetic term in the action takes the form of a sigma model. Here we investigate the phenomenological properties of this theory. We first consider the propagation of modes in the presence of gravity, and show that there is a unique choice of curvature coupling that leads to a the...

  17. (Sigma-Delta) Codes

    OpenAIRE

    Boulagouaz, M.; Leroy, A

    2013-01-01

    In this paper we introduce the notion of cyclic ($f(t),\\sigma,\\delta$)-codes for $f(t)\\in \\Ore$. These codes generalize the $\\theta$-codes as introduced by D. Boucher, F. Ulmer, W. Geiselmann \\cite{BGU}. We construct generic and control matrices for these codes. As a particular case the ($\\si,\\de$)-$W$-code associated to a Wedderburn polynomial are defined and we show that their control matrices are given by generalized Vandermonde matrices. All the Wedderburn polynomials of $\\mathbb F_q[t;\\t...

  18. Gravitating $\\sigma$ Model Solitons

    CERN Document Server

    Kim, Y; Kim, Yoonbai; Moon, Sei-Hoon

    1998-01-01

    We study axially symmetric static solitons of O(3) nonlinear $\\sigma$ model coupled to (2+1)-dimensional anti-de Sitter gravity. The obtained solutions are not self-dual under static metric. The usual regular topological lump solution cannot form a black hole even though the scale of symmetry breaking is increased. There exist nontopological solitons of half integral winding in a given model, and the corresponding spacetimes involve charged Ba$\\tilde n$ados-Teitelboim-Zanelli black holes without non-Abelian scalar hair.

  19. Staphylococcus aureus and Pregnancy

    Science.gov (United States)

    Staphylococcus aureus and Pregnancy In every pregnancy, a woman starts out with a 3-5% chance of ... risk. This sheet talks about whether exposure to staphylococcus aureus may increase the risk for birth defects ...

  20. Staphylococcus aureus toxins

    OpenAIRE

    Otto, Michael

    2013-01-01

    Staphylococcus aureus is a dangerous pathogen that causes a variety of severe diseases. The virulence of S. aureus is defined by a large repertoire of virulence factors, among which secreted toxins play a preeminent role. Many S. aureus toxins damage biological membranes, leading to cell death. In particular, S. aureus produces potent hemolysins and leukotoxins. Among the latter, some were recently identified to lyse neutrophils after ingestion, representing an especially powerful weapon agai...

  1. Observation of the Heavy Baryons Sigma b and Sigma b*.

    Science.gov (United States)

    Aaltonen, T; Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; DaRonco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, M; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dörr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garcia, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R-S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S

    2007-11-16

    We report an observation of new bottom baryons produced in pp collisions at the Tevatron. Using 1.1 fb(-1) of data collected by the CDF II detector, we observe four Lambda b 0 pi+/- resonances in the fully reconstructed decay mode Lambda b 0-->Lambda c + pi-, where Lambda c+-->pK* pi+. We interpret these states as the Sigma b(*)+/- baryons and measure the following masses: m Sigma b+=5807.8 -2.2 +2.0(stat.)+/-1.7(syst.) MeV/c2, m Sigma b- =5815.2+/-1.0(stat.)+/-1.7(syst.) MeV/c2, and m(Sigma b*)-m(Sigma b)=21.2-1.9 +2.0(stat.)-0.3+0.4(syst.) MeV/c2. PMID:18233134

  2. Design For Six Sigma

    OpenAIRE

    Greplová, Kristýna

    2012-01-01

    Cílem diplomové práce je analýza mezí praktického uplatnění obtokového ventilu TwinScroll turbodmychadla automobilu BMW X6 M užitím nástrojů DFSS (Design For Six Sigma). Cílem je tedy vytvoření speciálního přípravku pro měření těsnosti obtokového ventilu s možností otestování nejrůznějších charakteristik majících vliv na klíčové parametry turbodmychadla.

  3. Sigma models and string theory

    International Nuclear Information System (INIS)

    The authors present a pedagogical discussion of conformally invariant two-dimensional nonlinear sigma models and their relation to string theory. They show how to calculate the Weyl anomaly coefficients in the bosonic, supersymmetric and heterotic sigma models and explain their interpretation as string theory equations of motion for spacetime background fields

  4. Proteolysis of sigmaS (RpoS) and the general stress response in Escherichia coli.

    Science.gov (United States)

    Hengge, Regine

    2009-11-01

    The sigma(S) (RpoS) subunit of RNA polymerase is the master regulator of the general stress response in Escherichia coli. Regulation of sigma(S) occurs at the levels of transcription, translation, proteolysis and protein activity. As sigma(S) has become a paradigm for regulated proteolysis in bacteria, this review summarizes our current knowledge about the molecular mechanisms and multiple signal integration in sigma(S) degradation. PMID:19765651

  5. Spectra of coset sigma models

    International Nuclear Information System (INIS)

    We compute the complete 1-loop spectrum of anomalous dimensions for the bulk fields of non-linear sigma models on symmetric coset (super)spaces G/H, both with and without world-sheet supersymmetry. In addition, we provide two new methods for the construction of partition functions in the infinite radius limit and demonstrate their efficiency in the case of (super)sphere sigma models. Our results apply to a large number of target spaces including superspheres and superprojective spaces such as the N=2 sigma model on CP3|4

  6. Spectra of coset sigma models

    Energy Technology Data Exchange (ETDEWEB)

    Candu, Constantin [Institut fuer Theoretische Physik, Zuerich (Switzerland); Mitev, Vladimir [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Mathematik; Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Schomerus, Volker [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2013-08-15

    We compute the complete 1-loop spectrum of anomalous dimensions for the bulk fields of non-linear sigma models on symmetric coset (super)spaces G/H, both with and without world-sheet supersymmetry. In addition, we provide two new methods for the construction of partition functions in the infinite radius limit and demonstrate their efficiency in the case of (super)sphere sigma models. Our results apply to a large number of target spaces including superspheres and superprojective spaces such as the N=2 sigma model on CP{sup 3} {sup vertical} {sup stroke} {sup 4}.

  7. Lean Six Sigma For Dummies

    CERN Document Server

    Morgan, John

    2012-01-01

    Maximize the quality and efficiency of your organization If you want to make your organization or team more productive, you have to change the way it thinks. Combining the leading improvement methods of Six Sigma and Lean, this winning technique drives performance to the next level. But the jargon-packed language and theory of Lean Six Sigma can be intimidating for both beginners and experienced users. Whether you want to manage a project more tightly or fine-tune existing systems and processes, Lean Six Sigma For Dummies gives you plain-English guidance to achieve your business goals. Lean Si

  8. Wideband Sigma-Delta Modulators

    OpenAIRE

    Yuan, Xiaolong

    2010-01-01

    Sigma-delta modulators (SDM) have come up as an attractive candidatefor analog-to-digital conversion in single chip front ends thanks to the continuousimproving performance. The major disadvantage is the limited bandwidthdue to the need of oversampling. Therefore, extending these convertersto broadband applications requires lowering the oversampling ratio (OSR) inorder. The aim of this thesis is the investigation on the topology and structureof sigma-delta modulators suitable for wideband app...

  9. Running Head: Implementing Six Sigma Efforts

    Science.gov (United States)

    Lindsay, Jamie Eleaitia Mae

    2005-01-01

    Six Sigma is an organization wide program that provides common set of goals, language, and methodology for improving the overall quality of the processes within the organization (Davis & Heineke 2004). Six Sigma main concern is for the customer. What will the customers want? Need? Six Sigma has a model that helps Sigma get implemented DMAIC model…

  10. Predicting strength and function for promoters of the Escherichia coli alternative sigma factor, sigmaE.

    Science.gov (United States)

    Rhodius, Virgil A; Mutalik, Vivek K

    2010-02-16

    Sequenced bacterial genomes provide a wealth of information but little understanding of transcriptional regulatory circuits largely because accurate prediction of promoters is difficult. We examined two important issues for accurate promoter prediction: (1) the ability to predict promoter strength and (2) the sequence properties that distinguish between active and weak/inactive promoters. We addressed promoter prediction using natural core promoters recognized by the well-studied alternative sigma factor, Escherichia coli sigma(E), as a representative of group 4 sigmas, the largest sigma group. To evaluate the contribution of sequence to promoter strength and function, we used modular position weight matrix models comprised of each promoter motif and a penalty score for suboptimal motif location. We find that a combination of select modules is moderately predictive of promoter strength and that imposing minimal motif scores distinguished active from weak/inactive promoters. The combined -35/-10 score is the most important predictor of activity. Our models also identified key sequence features associated with active promoters. A conserved "AAC" motif in the -35 region is likely to be a general predictor of function for promoters recognized by group 4 sigmas. These results provide valuable insights into sequences that govern promoter strength, distinguish active and inactive promoters for the first time, and are applicable to both in vivo and in vitro measures of promoter strength. PMID:20133665

  11. Modulation of Fibronectin Adhesins and Other Virulence Factors in a Teicoplanin-Resistant Derivative of Methicillin-Resistant Staphylococcus aureus

    Science.gov (United States)

    Renzoni, Adriana; Francois, Patrice; Li, Dongmei; Kelley, William L.; Lew, Daniel P.; Vaudaux, Pierre; Schrenzel, Jacques

    2004-01-01

    The impact of glycopeptide resistance on the molecular regulation of Staphylococcus aureus virulence and attachment to host tissues is poorly documented. We compared stable teicoplanin-resistant methicillin-resistant S. aureus (MRSA) strain 14-4 with its teicoplanin-susceptible MRSA parent, strain MRGR3, which exhibits a high degree of virulence in a rat model of chronic foreign body MRSA infection. The levels of fibronectin-mediated adhesion and surface display of fibronectin-binding proteins were higher in teicoplanin-resistant strain 14-4 than in its teicoplanin-susceptible parent or a teicoplanin-susceptible revertant (strain 14-4rev) that spontaneously emerged during tissue cage infection. Quantitative reverse transcription-PCR (qRT-PCR) showed four- and twofold higher steady-state levels of fnbA and fnbB transcripts, respectively, in strain 14-4 than in its teicoplanin-susceptible counterparts. Analysis of global regulatory activities by qRT-PCR revealed a strong reduction in the steady-state levels of RNAIII and RNAII in the teicoplanin-resistant strain compared to in its teicoplanin-susceptible counterparts. In contrast, sarA mRNA levels were more than fivefold higher in strain 14-4 than in MRGR3 and 14-4rev. Furthermore, the alternative transcription factor sigma B had a higher level of functional activity in the teicoplanin-resistant strain than in its teicoplanin-susceptible counterparts, as evidenced by significant increases in both the sigma B-dependent asp23 mRNA levels and the sarA P3 promoter-derived transcript levels, as assayed by qRT-PCR and Northern blotting, respectively. These data provide further evidence that the emergence of glycopeptide resistance is linked by still poorly understood molecular pathways with significant pleiotropic changes in the expression and regulation of some major virulence genes. These molecular and phenotypic changes may have a profound impact on the bacterial adhesion and colonization properties of such

  12. Heat shock regulation of sigmaS turnover: a role for DnaK and relationship between stress responses mediated by sigmaS and sigma32 in Escherichia coli.

    OpenAIRE

    Muffler, A; M. Barth; Marschall, C; Hengge-Aronis, R

    1997-01-01

    The cellular level of the rpoS-encoded sigmaS subunit of RNA polymerase increases in response to various stress situations that include starvation, high osmolarity, and shift to acid pH, and these different stress signals differentially affect rpoS translation and/or sigmaS stability. Here we demonstrate that sigmaS is also induced by heat shock and that this induction is exclusively due to an interference with sigmaS turnover. Some sigmaS-dependent genes exhibit similar heat shock induction,...

  13. The SIGMA plants economic behavior

    International Nuclear Information System (INIS)

    In this work, the economical behavior of the Uranium Enrichment Plants, built using the Gaseous Isotopic Separation using Advanced Methods (SIGMA) (Separacion Isotopica Gaseosa por Metodos Avanzados) technology is analyzed. The calculations were made using an integrated computer code, where the cost of each main component of the plant is estimated. The program computes the production cost for several configurations of enrichment cascades, each one corresponding to a production rate. The program also includes a numerical optimizer and it seeks the SIGMA optimal configuration for a given set of design parameters. The present work does not contemplate the model and calculation of the auxiliary system costs. The total amortization cost is obtained by using the cascade capital cost and assuming that the auxiliary system represents a fixed part of the total cost.The results obtained show that the SIGMA technology for Enrichment Uranium Plants could achieve economical competition in a much lower production scale than the conventional Gaseous Diffusion Enrichment Plants. (author)

  14. The alternative sigma factor, sigmaS, affects polyhydroxyalkanoate metabolism in Pseudomonas putida.

    Science.gov (United States)

    Raiger-Iustman, Laura J; Ruiz, Jimena A

    2008-07-01

    To determine whether the stationary sigma factor, sigma(S), influences polyhydroxyalkanoate metabolism in Pseudomonas putida KT2440, an rpoS-negative mutant was constructed to evaluate polyhydroxyalkanoate accumulation and expression of a translational fusion to the promoter region of the genes that code for polyhydroxyalkanoate synthase 1 (phaC1) and polyhydroxyalkanoate depolymerase (phaZ). By comparison with the wild-type, the rpoS mutant showed a higher polyhydroxyalkanoate degradation rate and increased expression of the translational fusion during the stationary growth phase. These results suggest that sigma(S) might control the genes involved in polyhydroxyalkanoate metabolism, possibly in an indirect manner. In addition, survival and oxidative stress assays performed under polyhydroxyalkanoate- and nonpolyhydroxyalkanoate- accumulating conditions demonstrated that the accumulated polyhydroxyalkanoate increased the survival and stress tolerance of the rpoS mutant. According to this, polyhydroxyalkanoate accumulation would help cells to overcome the adverse conditions encountered during the stationary phase in the strain that lacks RpoS. PMID:18498401

  15. Measurement of ${\\sigma(H\

    CERN Document Server

    Milutinović-Dumbelović, G; Robson, A; Roloff, P

    2015-01-01

    This paper presents the potential measurement at 1.4 TeV CLIC of the cross-section (times branching ratio) of the Higgs production via $WW$ fusion with the Higgs subsequently decaying in $ZZ^\\ast$, ${\\sigma(H\

  16. The molecular basis of selective promoter activation by the sigmaS subunit of RNA polymerase.

    Science.gov (United States)

    Typas, Athanasios; Becker, Gisela; Hengge, Regine

    2007-03-01

    Different environmental stimuli cause bacteria to exchange the sigma subunit in the RNA polymerase (RNAP) and, thereby, tune their gene expression according to the newly emerging needs. Sigma factors are usually thought to recognize clearly distinguishable promoter DNA determinants, and thereby activate distinct gene sets, known as their regulons. In this review, we illustrate how the principle sigma factor in stationary phase and in stressful conditions in Escherichia coli, sigmaS (RpoS), can specifically target its large regulon in vivo, although it is known to recognize the same core promoter elements in vitro as the housekeeping sigma factor, sigma70 (RpoD). Variable combinations of cis-acting promoter features and trans-acting protein factors determine whether a promoter is recognized by RNAP containing sigmaS or sigma70, or by both holoenzymes. How these promoter features impose sigmaS selectivity is further discussed. Moreover, additional pathways allow sigmaS to compete more efficiently than sigma70 for limiting amounts of core RNAP (E) and thereby enhance EsigmaS formation and effectiveness. Finally, these topics are discussed in the context of sigma factor evolution and the benefits a cell gains from retaining competing and closely related sigma factors with overlapping sets of target genes. PMID:17302812

  17. Predicting $D \\to \\sigma\\pi$

    CERN Document Server

    Gatto, R; Polosa, Antonio; Törnqvist, N A

    2000-01-01

    We examine the D -> sigma pi amplitude through a constituent quark-meson model, incorporating heavy quark and chiral symmetries, finding a good agreement with the recent E791 data analysis of D -> 3 pi via sigma.

  18. Development of a potential stationary-phase specific gene expression system by engineering of SigB-dependent cg3141 promoter in Corynebacterium glutamicum.

    Science.gov (United States)

    Kim, Min Jeong; Yim, Sung Sun; Choi, Jae Woong; Jeong, Ki Jun

    2016-05-01

    Corynebacterium glutamicum is a non-pathogenic, non-sporulating Gram-positive soil bacterium that has been used for the industrial production of various proteins and chemicals. To achieve enhanced and economical production of target molecules, the development of strong auto-inducible promoters is desired, which can be activated without expensive inducers and has significant advantages for industrial-scale use. Here, we developed a stationary-phase gene expression system by engineering a sigma factor B (SigB)-dependent promoter that can be activated during the transition phase between exponential and stationary growth phases in C. glutamicum. First, the inducibilities of three well-known SigB-dependent promoters were examined using super-folder green fluorescent protein as a reporter protein, and we found that promoter of cg3141 (P cg3141 ) exhibited the highest inducibility. Next, a synthetic promoter library was constructed by randomizing the flanking and space regions of P cg3141 , and the stationary-phase promoters exhibiting high strengths were isolated via FACS-based high-throughput screening. The isolated synthetic promoter (P4-N14) showed a 3.5-fold inducibility and up to 20-fold higher strength compared to those of the original cg3141 promoter. Finally, the use of the isolated P4-N14 for fed-batch cultivation was verified with the production of glutathione S-transferase as a model protein in a lab-scale (5-L) bioreactor. PMID:26782746

  19. Topological Sigma Models On Supermanifolds

    CERN Document Server

    Jia, Bei

    2016-01-01

    This paper concerns constructing topological sigma models governing maps from semirigid super Riemann surfaces to general target supermanifolds. We define both the A model and B model in this general setup by defining suitable BRST operators and physical observables. Using supersymmetric localization, we express correlation functions in these theories as integrals over suitable supermanifolds. In the case of the A model, we obtain an integral over the supermoduli space of "superinstantons". The language of supergeometry is used extensively throughout this paper.

  20. Pion (Kaon) and Sigma polarizabilities

    International Nuclear Information System (INIS)

    We report the results of the working group on ''Pion (Kaon) and Sigma Polarizabilities''. Interesting possibilities to measure these polarizabilities include the radiative pion photoproduction in the MAMI experiment at Mainz, as well as at the GRAAL facility (actually the latter is being considered for an experimental determination of the pion polarizabilities here for the first time), the experimental plans on Primakoff effect at FNAL, and the measurements at the Frascati Φ-factory DAΦNE. (orig.)

  1. Pion (kaon) and sigma polarizabilities

    CERN Document Server

    Bellucci, S

    1995-01-01

    We report the results of the working group on ``Pion (Kaon) and Sigma Polarizabilities''. Interesting possibilities to measure these polarizabilities include the radiative pion photoproduction in the MAMI experiment at Mainz, as well as at the GRAAL facility (actually the latter is being considered for an experimental determination of the pion polarizabilities here for the first time), the experimental plans on Primakoff effect at FNAL, and the measurements at the Frascati \\Phi-factory DA\\PhiNE.

  2. Pion (Kaon) and Sigma polarizabilities

    OpenAIRE

    Bellucci, S.

    1995-01-01

    We report the results of the working group on ``Pion (Kaon) and Sigma Polarizabilities''. Interesting possibilities to measure these polarizabilities include the radiative pion photoproduction in the MAMI experiment at Mainz, as well as at the GRAAL facility (actually the latter is being considered for an experimental determination of the pion polarizabilities here for the first time), the experimental plans on Primakoff effect at FNAL, and the measurements at the Frascati $\\Phi$-factory DA$\\...

  3. Visual Six Sigma Making Data Analysis Lean

    CERN Document Server

    Cox, Ian; Ramsey, Philip J

    2010-01-01

    Through Visual Six Sigma, learn what your data is telling your business. In the typical business environment of process improvement, you want simple-to-use tools that everyone can use at all levels to rapidly explore and interpret data. Visual Six Sigma: Making Data Analysis Lean helps you use your own data to drive incredible improvement within your business. Divided into three parts-background, case studies, and JMP highlights- Visual Six Sigma covers.: Six Sigma and Visual Six Sigma; A first look at JMP; Transforming pricing management; Improving white polymer manufacturing; Designing exper

  4. The sausage sigma model revisited

    CERN Document Server

    Suneeta, Vardarajan

    2014-01-01

    Fateev's sausage sigma models in two and three dimensions are known to be integrable. We study their stability under RG flow in the target space by using results from the mathematics of Ricci flow. We show that the three dimensional sausage is unstable, whereas the two dimensional sausage appears to be stable at least at leading order as it approaches the sphere. The $n$-sphere, corresponding to the integrable O(n) sigma model, is geometrically stable and an attractor for nearby solutions to RG flow. We speculate that the stability results obtained seem to be linked to the classification of ancient solutions to Ricci flow (i.e., sigma models which are asymptotically free in the UV and nontrivial in the IR) in two and three dimensions. We also describe a class of perturbations of the three dimensional sausage (with the same continuous symmetries) which remarkably decouple. This indicates that there could be a new solution to RG flow which is described at least perturbatively as a deformation of the sausage.

  5. Staphylococcus aureus CC398

    DEFF Research Database (Denmark)

    Price, Lance B.; Stegger, Marc; Hasman, Henrik;

    2012-01-01

    Since its discovery in the early 2000s, methicillin-resistant Staphylococcus aureus (MRSA) clonal complex 398 (CC398) has become a rapidly emerging cause of human infections, most often associated with livestock exposure. We applied whole-genome sequence typing to characterize a diverse collection...... of CC398 isolates (n = 89), including MRSA and methicillin-susceptible S. aureus (MSSA) from animals and humans spanning 19 countries and four continents. We identified 4,238 single nucleotide polymorphisms (SNPs) among the 89 core genomes. Minimal homoplasy (consistency index = 0.9591) was detected...

  6. Role of the response regulator RssB in sigma recognition and initiation of sigma proteolysis in Escherichia coli.

    Science.gov (United States)

    Klauck, E; Lingnau, M; Hengge-Aronis, R

    2001-06-01

    In growing Escherichia coli cells, the master regulator of the general stress response, sigmaS (RpoS), is subject to rapid proteolysis. In response to stresses such as sudden carbon starvation, osmotic upshift or shift to acidic pH, sigmaS degradation is inhibited, sigmaS accumulates and numerous sigmaS-dependent genes with stress-protective functions are activated. sigmaS proteolysis is dependent on ClpXP protease and the response regulator RssB, whose phosphorylated form binds directly to sigmaS in vitro. Here, we show that substitutions of aspartate 58 (D58) in RssB, which result in higher sigmaS levels in vivo, produce RssB variants unable to bind sigmaS in vitro. Thus, RssB is the direct substrate recognition factor in sigmaS proteolysis, whose affinity for sigmaS depends on phosphorylation of its D58 residue. RssB does not dimerize or oligomerize upon this phosphorylation and sigmaS binding, and RssB and sigmaS exhibit a 1:1 stoichiometry in the complex. The receiver as well as the output domain of RssB are required for sigmaS binding (as shown in vivo and in vitro) and for complementation of an rssB null mutation. Thus, the N-terminal receiver domain plays an active and positive role in RssB function. Finally, we demonstrate that RssB is not co-degraded with sigmaS, i.e. RssB has a catalytic role in the initiation of sigmaS turnover. A model is presented that integrates the details of RssB-sigmaS interaction, the RssB catalytic cycle and potential stress signal input in the control of sigmaS proteolysis. PMID:11442836

  7. TonB-Dependent outer-membrane proteins and siderophore utilization in Pseudomonas fluorescens Pf-5

    Science.gov (United States)

    The soil bacterium Pseudomonas fluorescens Pf-5 produces two siderophores, a pyoverdine and enantio-pyochelin, and its proteome includes 45 TonB-dependent outer-membrane proteins, which commonly function in uptake of siderophores and other substrates from the environment. The 45 proteins share the ...

  8. Sigma Factors for Cyanobacterial Transcription

    Directory of Open Access Journals (Sweden)

    Sousuke Imamura

    2009-04-01

    Full Text Available Cyanobacteria are photosynthesizing microorganisms that can be used as a model for analyzing gene expression. The expression of genes involves transcription and translation. Transcription is performed by the RNA polymerase (RNAP holoenzyme, comprising a core enzyme and a sigma (σ factor which confers promoter selectivity. The unique structure, expression, and function of cyanobacterial σ factors (and RNAP core subunits are summarized here based on studies, reported previously. The types of promoter recognized by the σ factors are also discussed with regard to transcriptional regulation.

  9. Comments on noncommutative sigma models

    International Nuclear Information System (INIS)

    We review the derivation of a noncommutative version of the nonlinear sigma model on CPn and it's soliton solutions for finite θ emphasizing the similarities it bears to the GMS scalar field theory. It is also shown that unlike the scalar theory, some care needs to be taken in defining the topological charge of BPS solitons of the theory due to nonvanishing surface terms in the energy functional. Finally it is shown that, like its commutative analogue, the noncommutative CPn-model also exhibits a non-BPS sector. Unlike the commutative case however, there are some surprises in the noncommutative case that merit further study. (author)

  10. Cohomological reduction of sigma models

    International Nuclear Information System (INIS)

    This article studies some features of quantum field theories with internal supersymmetry, focusing mainly on 2-dimensional non-linear sigma models which take values in a coset superspace. It is discussed how BRST operators from the target space super- symmetry algebra can be used to identify subsectors which are often simpler than the original model and may allow for an explicit computation of correlation functions. After an extensive discussion of the general reduction scheme, we present a number of interesting examples, including symmetric superspaces G/GZ2 and coset superspaces of the form G/GZ4. (orig.)

  11. Positioning of sigma(S), the stationary phase sigma factor, in Escherichia coli RNA polymerase-promoter open complexes.

    OpenAIRE

    Colland, F; Fujita, N; Kotlarz, D; Bown, J A; Meares, C F; Ishihama, A; Kolb, A

    1999-01-01

    The sigma(S) subunit of RNA polymerase is the master regulator of the general stress response in Escherichia coli and is required for promoter recognition of many stationary phase genes. We have analysed open complexes of Esigma(S) RNA polymerase, using sigma(S) derivatives carrying single cysteine residues at nine different positions to which the reagent FeBABE has been tethered. All holoenzymes but one formed transcriptionally active open complexes at three different promoters (osmY, galP1 ...

  12. Pion and Sigma Polarizabilities and Radiative Transitions

    OpenAIRE

    Moinester, Murray A.

    1994-01-01

    Fermilab E781 plans measurements of gamma-Sigma and $\\gamma$-pion interactions using a 600 GeV beam of Sigmas and pions, and a virtual photon target. Pion polarizabilities and radiative transitions will be measured in this experiment. The former can test a precise prediction of chiral symmetry; the latter for a_1(1260) ----> pi + gamma is important for understanding the polarizability. The experiment also measures polarizabilities and radiative transitions for Sigma hyperons. The polarizabili...

  13. Operation of six sigma in production engineering

    OpenAIRE

    Eduardo José Pereira Martin; Luís Henrique Fogueiral de Camargo; Elisabete Aparecida Zambelo

    2016-01-01

    In an increasingly competitive world, where deadlines and targets are becoming more narrow and difficult to achieve, organizations are seeking new competitive advantages that allow them to improve their development, and it is in this context that the Six Sigma program offers a way to enable such income. This study consists of a literature review on the topic: Six Sigma; and a bibliometric review in order to identify the use of the Six Sigma program in Production Engineering. The d...

  14. Pion-delta sigma-term

    OpenAIRE

    Cavalcante, I. P.; Robilotta, M. R.; Borges, J. Sa; Santos, D. de O.; Zarnauskas, G. R. S.

    2005-01-01

    We use a configuration space chiral model in order to evaluate nucleon and delta sigma-terms. Analytic expressions are consistent with chiral counting rules and give rise to expected non-analytic terms in the chiral limit. We obtain the results $\\sigma_N=46$ MeV and $\\sigma_{\\Delta}=32$ MeV, which are very close to values extracted from experiment and produced by other groups.

  15. Lean Six Sigma in financial services

    OpenAIRE

    Koning, de, L.J.; Does, R.J.M.M.; Bisgaard, S.

    2008-01-01

    Lean Thinking and Six Sigma are typically considered as separate approaches to process innovation, with complementary strengths. When combined as Lean Six Sigma, this approach provides a unified framework for systematically developing innovations. Lean Six Sigma can also bring about significant results and breakthrough improvements in financial services, as demonstrated with four case studies from Dutch multinational insurance companies. These cases demonstrate the importance of incremental i...

  16. Structural determinants of sigma receptor affinity

    International Nuclear Information System (INIS)

    The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-[3H]3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent

  17. Structural determinants of sigma receptor affinity

    Energy Technology Data Exchange (ETDEWEB)

    Largent, B.L.; Wikstroem, H.G.; Gundlach, A.L.; Snyder, S.H.

    1987-12-01

    The structural determinants of sigma receptor affinity have been evaluated by examining a wide range of compounds related to opioids, neuroleptics, and phenylpiperidine dopaminergic structures for affinity at sigma receptor-binding sites labeled with (+)-(/sup 3/H)3-PPP. Among opioid compounds, requirements for sigma receptor affinity differ strikingly from the determinants of affinity for conventional opiate receptors. Sigma sites display reverse stereoselectivity to classical opiate receptors. Multi-ringed opiate-related compounds such as morphine and naloxone have negligible affinity for sigma sites, with the highest sigma receptor affinity apparent for benzomorphans which lack the C ring of opioids. Highest affinity among opioids and other compounds occurs with more lipophilic N-substituents. This feature is particularly striking among the 3-PPP derivatives as well as the opioids. The butyrophenone haloperidol is the most potent drug at sigma receptors we have detected. Among the series of butyrophenones, receptor affinity is primarily associated with the 4-phenylpiperidine moiety. Conformational calculations for various compounds indicate a fairly wide range of tolerance for distances between the aromatic ring and the amine nitrogen, which may account for the potency at sigma receptors of structures of considerable diversity. Among the wide range of structures that bind to sigma receptor-binding sites, the common pharmacophore associated with high receptor affinity is a phenylpiperidine with a lipophilic N-substituent.

  18. Physiological effects of Crl in Salmonella are modulated by sigmaS level and promoter specificity.

    Science.gov (United States)

    Robbe-Saule, Véronique; Lopes, Miguel Dias; Kolb, Annie; Norel, Françoise

    2007-04-01

    The small regulatory protein Crl activates sigma(S) (RpoS), the stationary-phase and general stress response sigma factor. Crl has been reported to bind sigma(S) in vitro and to facilitate the formation of RNA polymerase holoenzyme. In Salmonella enterica serovar Typhimurium, Crl is required for the development of the rdar morphotype and transcription initiation of the sigma(S)-dependent genes csgD and adrA, involved in curli and cellulose production. Here, we examined the expression of other sigma(S)-dependent phenotypes and genes in a Deltacrl mutant of Salmonella. Gene fusion analyses and in vitro transcription assays indicate that the magnitude of Crl activation differs between promoters and is highly dependent on sigma(S) levels. We replaced the wild-type rpoS allele in S. enterica serovar Typhimurium strain ATCC 14028 with the rpoS(LT2) allele that shows reduced expression of sigma(S); the result was an increased Crl activation ratio and larger physiological effects of Crl on oxidative, thermal, and acid stress resistance levels during stationary phase. We also found that crl, rpoS, and crl rpoS strains grew better on succinate than did the wild type and expressed the succinate dehydrogenase sdhCDBA operon more strongly. The crl and rpoS(LT2) mutations also increased the competitive fitness of Salmonella in stationary phase. These results show that Crl contributes to negative regulation by sigma(S), a finding consistent with a role for Crl in sigma factor competition via the facilitation of sigma(S) binding to core RNA polymerase. PMID:17293430

  19. Exploring the Supersymmetric $\\sigma$ Model

    CERN Document Server

    De Oliveira-Imbiriba, B C

    1999-01-01

    The purpose of this work is to present some basic concepts about the non-linear sigma model in a simple and direct way. We start with showing the bosonic model and the Wess-Zumino-Witten term, making some comments about its topological nature, and its association with the torsion. It is also shown that to cancel the quantum conformal anomaly the model should obey the Einstein equations. We provide a quick introduction about supersymmetry in chapter 2 to help the understanding the supersymmetric extension of the model. In the last chapter we present the supersymmetric model and its equations of motion. Finally we work-out the two-supersymmetry case, introducing the chiral as well as the twisted chiral fields, expliciting the very specific $SU(2)\\otimes U(1)$ case.

  20. The free $\\sigma$CFTs

    CERN Document Server

    Guerrieri, Andrea; Wen, Congkao

    2016-01-01

    We introduce the conformal field theories that describe the shadows of the lowest dimension composites made out of massless free scalars and fermions in $d$ dimensions. We argue that these theories can be consistently defined as free CFTs for even $d\\geq 4$. We use OPE techniques to study their spectrum and show that for $d\\rightarrow\\infty$ it matches that of free bosonic CFTs in $d=6$ and $d=4$ dimensions. For these $\\sigma$CFTs we calculate $c_T$ in $d=6,8,10$ and $12$ dimensions using the OPE and also a direct construction of their higher-derivative energy momentum tensors. Our results agree with the general proposal of arXiv:1601.07198.

  1. Geometry of Membrane Sigma Models

    CERN Document Server

    Vysoky, Jan

    2015-01-01

    String theory still remains one of the promising candidates for a unification of the theory of gravity and quantum field theory. One of its essential parts is relativistic description of moving multi-dimensional objects called membranes (or p-branes) in a curved spacetime. On the classical field theory level, they are described by an action functional extremalising the volume of a manifold swept by a propagating membrane. This and related field theories are collectively called membrane sigma models. Differential geometry is an important mathematical tool in the study of string theory. It turns out that string and membrane backgrounds can be conveniently described using objects defined on a direct sum of tangent and cotangent bundles of the spacetime manifold. Mathematical field studying such object is called generalized geometry. Its integral part is the theory of Leibniz algebroids, vector bundles with a Leibniz algebra bracket on its module of smooth sections. Special cases of Leibniz algebroids are better ...

  2. Linear Sigma Models with Torsion

    CERN Document Server

    Quigley, Callum

    2011-01-01

    Gauged linear sigma models with (0,2) supersymmetry allow a larger choice of couplings than models with (2,2) supersymmetry. We use this freedom to find a fully linear construction of torsional heterotic compactifications, including models with branes. As a non-compact example, we describe a family of metrics which correspond to deformations of the heterotic conifold by turning on H-flux. We then describe compact models which are gauge-invariant only at the quantum level. Our construction gives a generalization of symplectic reduction. The resulting spaces are non-Kahler analogues of familiar toric spaces like complex projective space. Perturbatively conformal models can be constructed by considering intersections.

  3. Resurrection of the $\\sigma$ meson

    CERN Document Server

    Törnqvist, N A; Tornqvist, Nils A; Roos, Matts

    1995-01-01

    It is shown from a very general model and an analysis of data on the lightest 0++ meson nonet that the f0(980) and f0(1200) resonance poles are two manifestations of the same ss state. Similarily the a0(980) and the a0(1450) are likely to be two manifestations of the same qq state. On the other hand, the uu+dd state, when unitarized and strongly distorted by hadronic mass shifts, becomes an extremely broad Breit-Wigner-like background, m=860 MeV, Gamma=880 MeV, with its pole at s=(0.158-i0.235) GeV^2. This we identify with the sigma meson required by models for spontaneous breaking of chiral symmetry.

  4. Sigma meson in heavy ion collision

    International Nuclear Information System (INIS)

    We want to present a short theoretical prediction of the behaviour of the sigma meson in heavy ion collisions. It is considered that the sigma meson is a pion-pion correlation, resulting from the decay of the N*(1440) resonance. There will be presented some QMD simulations. (authors)

  5. THE LEAN AND SIX SIGMA SINERGY

    Directory of Open Access Journals (Sweden)

    Mirko Sokovic

    2008-12-01

    Full Text Available Many organizations, dealing with continuous improvement methods, have realized that Lean and Six Sigma methodologies complement each other. Lean manufacturing focuses on the remova l of waste so that all processes in the total system add value from the customers' perspectives. The main emphasis of Six Sigma is the application of statistical tools in a disciplined manner, which requires data-driven decision-making. The integration of Lean and Six Sigma provides a synergetic effect, a rapid process improvement strategy for attaining organizational goals. When separated, Lean manufacturing cannot bring a process under statistical control, and Six Sigma cannot dramatically improve cycle time or reduce invested capital. Together, synergistic qualities are created to maximize the potential for a process improvement. The paper deals with Lean and Six Sigma principles and approaches used in modern manufacturing for process improvements, and bring forward benefits that are gained when these two methodologies are integrated.

  6. Exploiting Six Sigma by using DTS

    Directory of Open Access Journals (Sweden)

    Anuradha

    2011-05-01

    Full Text Available Six Sigma has been very successfully applied in manufacturing. Is it also applicable to software, and ICT? Six Sigma is about cost reduction by eliminating defects. Six Sigma uses the following three principles: Focus on customers, Process orientation, Leadership based on metrics The big question as to whether Six Sigma can really be applied as successfully in the software industry as it was to manufacturing is still being debated. The real challenge is to see if it can be implemented without reinventing the wheel. There is also disagreement among leaders in the software industry about the need for Six Sigma. Applying Six Sigma to software development makes software projects transparent to both management and customers. Transparency requires an important cultural change. As a result, after transparency is achieved, completing accurate project estimations while meeting both deadlines and customer requirements becomes a lot easier. I had implemented DTS as a prototype by using techniques of six sigma to track an error. With the help of graph I also show the no. of bug incremented or decremented versus date of track.

  7. TLR-mediated NF-kB-dependent cytokine production is differently affected by HIV therapeutics

    DEFF Research Database (Denmark)

    Melchjorsen, Jesper; Paludan, Søren Riis; Mogensen, Trine; Tolstrup, Martin; Østergaard, Lars Jørgen

      Pathogen-recognizing Toll-like receptors 2 (TLR2) and TLR4 are known to recognize a number of pathogens, including E.Coli, S. Pneumonia and N. Meningococcus. We have studied whether a number of HIV therapeutics affect immediate proinflammatory cytokine responses in cell cultures. Preliminary...... results suggest an opposing effect of the drugs Tenofovir and Retrovir (AZT) on TLR-mediated production of NF-kappaB-dependent proinflammatory cytokines. We present data on the mechanisms behind the drug-mediated remodeling of innate immune activation and how the drugs effect early host...

  8. SigmaS controls multiple pathways associated with intracellular multiplication of Legionella pneumophila.

    Science.gov (United States)

    Hovel-Miner, Galadriel; Pampou, Sergey; Faucher, Sebastien P; Clarke, Margaret; Morozova, Irina; Morozov, Pavel; Russo, James J; Shuman, Howard A; Kalachikov, Sergey

    2009-04-01

    Legionella pneumophila is the causative agent of the severe and potentially fatal pneumonia Legionnaires' disease. L. pneumophila is able to replicate within macrophages and protozoa by establishing a replicative compartment in a process that requires the Icm/Dot type IVB secretion system. The signals and regulatory pathways required for Legionella infection and intracellular replication are poorly understood. Mutation of the rpoS gene, which encodes sigma(S), does not affect growth in rich medium but severely decreases L. pneumophila intracellular multiplication within protozoan hosts. To gain insight into the intracellular multiplication defect of an rpoS mutant, we examined its pattern of gene expression during exponential and postexponential growth. We found that sigma(S) affects distinct groups of genes that contribute to Legionella intracellular multiplication. We demonstrate that rpoS mutants have a functional Icm/Dot system yet are defective for the expression of many genes encoding Icm/Dot-translocated substrates. We also show that sigma(S) affects the transcription of the cpxR and pmrA genes, which encode two-component response regulators that directly affect the transcription of Icm/Dot substrates. Our characterization of the L. pneumophila small RNA csrB homologs, rsmY and rsmZ, introduces a link between sigma(S) and the posttranscriptional regulator CsrA. We analyzed the network of sigma(S)-controlled genes by mutational analysis of transcriptional regulators affected by sigma(S). One of these, encoding the L. pneumophila arginine repressor homolog gene, argR, is required for maximal intracellular growth in amoebae. These data show that sigma(S) is a key regulator of multiple pathways required for L. pneumophila intracellular multiplication. PMID:19218380

  9. SIGMA WEB INTERFACE FOR REACTOR DATA APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko,B.; Sonzogni, A.A.

    2010-05-09

    We present Sigma Web interface which provides user-friendly access for online analysis and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The interface includes advanced browsing and search capabilities, interactive plots of cross sections, angular distributions and spectra, nubars, comparisons between evaluated and experimental data, computations for cross section data sets, pre-calculated integral quantities, neutron cross section uncertainties plots and visualization of covariance matrices. Sigma is publicly available at the National Nuclear Data Center website at http://www.nndc.bnl.gov/sigma.

  10. Measurements of the $\\Sigma_{c}^{0}$ and $\\Sigma_{c}^{++}$ Mass Splittings

    CERN Document Server

    Link, J M; Reyes, M; Yager, P M; Anjos, J C; Bediaga, I; Göbel, C; Magnin, J; De Miranda, J M; Pepe, I M; Dos Reis, A C; Simão, F R A; Carrillo, S; Casimiro, E; Méndez, H; Sánchez-Hernández, A; Uribe, C; Vázquez, F; Cinquini, L; Cumalat, J P; Ramírez, J E; O'Reilly, B; Vaandering, E W; Butler, J N; Cheung, H W K; Gaines, I; Garbincius, P H; Garren, L A; Gottschalk, E E; Gourlay, S A; Kasper, P H; Kreymer, A E; Kutschke, R; Bianco, S; Fabbri, Franco Luigi; Sarwar, S; Zallo, A; Cawlfield, C; Kim, D Y; Park, K S; Rahimi, A; Wiss, J; Gardner, R; Chung, Y S; Kang, J S; Ko, B R; Kwak, J W; Lee, K B; Myung, S S; Park, H; Alimonti, G; Boschini, M; Brambilla, D; Caccianiga, B; Calandrino, A; D'Angelo, P; Di Corato, M; Dini, P; Giammarchi, M G; Inzani, P; Leveraro, F; Malvezzi, S; Menasce, D; Mezzadri, M; Milazzo, L; Moroni, L; Pedrini, D; Prelz, F; Rovere, M; Sala, A; Sala, S; Davenport, T F; Arena, V; Boca, G; Bonomi, G; Gianini, G; Liguori, G; Merlo, M; Pantea, D; Ratti, S P; Riccardi, C; Torre, P; Viola, L; Vitulo, P; Hernández, H; López, A M; Méndez, L; Mirles, M A; Montiel, E; Olaya, D; Quinones, J; Rivera, C; Zhang, Y; Copty, N K; Purohit, M; Wilson, J R; Cho, K; Handler, T; Engh, D; Johns, W E; Hosack, M; Nehring, M S; Sales, M; Sheldon, P D; Stenson, K; Webster, M S; Sheaff, M; Kwon, Y J

    2000-01-01

    Using a high statistics sample of photoproduced charmed particles from the FOCUS experiment at Fermilab (FNAL-E831), we measure the mass splittings of the charmed baryons Sigma_c^0 and Sigma_c^{++}. We find M(Sigma_c^0 - Lambda_c^+) = 167.38 +/- 0.21 +/- 0.13 MeV/c^2 and M(Sigma_c^++ - Lambda_c^+) = 167.35 +/- 0.19 +/- 0.12 MeV/c^2 with samples of 362 +/- 36 and 461 +/- 39 events, respectively. We measure the isospin mass splitting M(Sigma_c^++ - Sigma_c^0) to be -0.03 +/- 0.28 +/- 0.11 Mev/c^2. The first errors are statistical and the second are systematic.

  11. Measurement of Natural Widths of Sigma-c-0 and Sigma-c-++ Baryons

    CERN Document Server

    Link, J M; Reyes, M; Yager, P M; Anjos, J C; Bediaga, I; Göbel, C; Magnin, J; Massafferri, A; De Miranda, J M; Pepe, I M; Dos Reis, A C; Carrillo, S; Casimiro, E; Cuautle, E; Sánchez-Hernández, A; Uribe, C; Vázquez, F; Agostino, L; Cinquini, L; Cumalat, J P; O'Reilly, B; Ramírez, J E; Segoni, I; Butler, J N; Cheung, H W K; Chiodini, G; Gaines, I; Garbincius, P H; Garren, L A; Gottschalk, E; Kasper, P H; Kreymer, A E; Kutschke, R; Bianco, S; Fabbri, Franco Luigi; Zallo, A; Cawlfield, C; Kim, D Y; Rahimi, A; Wiss, J; Gardner, R; Kryemadhi, A; Chung, Y S; Kang, J S; Ko, B R; Kwak, J W; Lee, K B; Park, H; Alimonti, G; Barberis, S; Boschini, M; D'Angelo, P; Di Corato, M; Dini, P; Edera, L; Erba, S; Giammarchi, M; Inzani, P; Leveraro, F; Malvezzi, S; Menasce, D; Mezzadri, M; Milazzo, L; Moroni, L; Pedrini, D; Pontoglio, C; Prelz, F; Rovere, M; Sala, S; Davenport, T F; Arena, V; Boca, G; Bonomi, G; Gianini, G; Liguori, G; Merlo, M M; Pantea, D; Ratti, S P; Riccardi, C; Vitulo, P; Hernández, H; López, A M; Méndez, H; Méndez, L; Montiel, E; Olaya, D; Paris, A; Quinones, J; Rivera, C; Xiong, W; Zhang, Y; Wilson, J R; Cho, K; Handler, T; Mitchell, R; Engh, D; Hosack, M; Johns, W E; Nehring, M; Sheldon, P D; Stenson, K; Vaandering, E W; Webster, M; Sheaff, M

    2002-01-01

    In this paper we present a measurement of the natural widths of $\\Sigma_c^0$ and $\\Sigma_c^{++}$. Using data from the FOCUS experiment, we find $\\Gamma(\\Sigma_c^0) = 1.55 +0.41/-0.37 \\pm 0.38$ MeV/c^2 and $\\Gamma(\\Sigma_c^0) = 2.05 +0.41/-0.38 \\pm 0.38$ MeV/c^2. The first errors are statistical, the second systematic. These results are obtained with a sample of 913 $\\Sigma_c^0 \\to \\Lambda_c^+ \\pi^-$ decays and 1110 $\\Sigma_c^++ \\to \\Lambda_c^+ \\pi^+$ decays. These results are compared with recent theoretical predictions. PACS numbers: 14.20.Lq 13.30Eg

  12. $\\Sigma^-$ admixture in the $^{10}_\\Lambda$Li hypernucleus with a repulsive $\\Sigma$-nucleus potential

    CERN Document Server

    Lanskoy, D E

    2013-01-01

    $\\Sigma^-$ hyperon component of the $^{10}_\\Lambda$Li wave function is studied. The $\\Sigma^-$ admixture is vital for production of neutron-rich $\\Lambda$ hypernuclei via mesonic beams. We use a simplified shell model wave function for the $\\Lambda$ channel and calculate the $\\Sigma^-$ admixture directly from coupled equations. Probability of the $\\Sigma^-$ admixture for realistic repulsive $\\Sigma^-$-nucleus potentials is less by several times than that for attractive potentials and does not exceed $0.1\\%$. We conclude that the cross sections of the $^{10}\\mbox{B}(\\pi^-,K^+){}^{10}_\\Lambda\\mbox{Li}$ reaction measured at KEK cannot be explained by production via $\\Sigma^-$ admixture as a doorway state.

  13. Photon emission within the linear sigma model

    CERN Document Server

    Wunderlich, F

    2015-01-01

    Soft-photon emission rates are calculated within the linear sigma model. The investigation is aimed at answering the question to which extent the emissivities map out the phase structure of this particular effective model of strongly interacting matter.

  14. Effect of growth temperature on Crl-dependent regulation of sigmaS activity in Salmonella enterica serovar Typhimurium.

    Science.gov (United States)

    Robbe-Saule, Véronique; Carreira, Ingrid; Kolb, Annie; Norel, Françoise

    2008-07-01

    The small regulatory protein Crl favors association of the stationary-phase sigma factor sigma(S) (RpoS) with the core enzyme polymerase and thereby increases sigma(S) activity. Crl has a major physiological impact at low levels of sigma(S). Here, we report that the Crl effects on sigma(S)-dependent gene expression, the H(2)O(2) resistance of Salmonella enterica serovar Typhimurium, and the resistance of this organism to acidic pH are greater at 28 degrees C than at 37 degrees C. Immunoblot experiments revealed a negative correlation between sigma(S) and Crl levels; the production of Crl was slightly greater at 28 degrees C than at 37 degrees C, whereas the sigma(S) levels were about twofold lower at 28 degrees C than at 37 degrees C. At both temperatures, Crl was present in excess of sigma(S), and increasing the Crl level further did not increase the H(2)O(2) resistance level of Salmonella and the expression of the sigma(S)-dependent gene katE encoding the stationary-phase catalase. In contrast, increasing the sigma(S) level rendered Salmonella more resistant to H(2)O(2) at 28 degrees C, increased the expression of katE, and reduced the magnitude of Crl activation. In addition, the effect of Crl on katE transcription in vitro was not dependent on temperature. These results suggest that the effect of temperature on Crl-dependent regulation of the katE gene and H(2)O(2) resistance are mediated mainly via an effect on sigma(S) levels. In addition, our results revealed that sigma(S) exerts a negative effect on the production of Crl in stationary phase when the cells contain high levels of sigma(S). PMID:18456810

  15. Seismic Hazard Mapping inside the Project SIGMA

    OpenAIRE

    Tusa, Giuseppina; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Cannata, Andrea; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Cassisi, Carmelo; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; D'Amico, Salvatore; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Montalto, Placido; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia; Patanè, Domenico; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Catania, Catania, Italia

    2014-01-01

    The Project SIGMA (Sistema Integrato di sensori in ambiente cloud per la Gestione Multirischio Avanzata) arises from the fields of Information and Communications Technologies (ICT) and advanced applications for the control, monitoring and management of high-risk processes of natural and social origin. SIGMA is a multilevel architecture whose main aim is the acquisition, integration and processing of heterogeneous data from different sources (seismic, volcanic, meteorologic, hydric...

  16. Extracytoplasmic function sigma factors in Pseudomonas syringae

    DEFF Research Database (Denmark)

    Kiil, Kristoffer; Oguiza, J.A.; Ussery, D.W.

    2005-01-01

    Genome analyses of the plant pathogens Pseudomonas syringae pv. tomato DC3000, pv. syringae B728a and pv. phaseolicola 1448A reveal fewer extracytoplasmic function (ECF) sigma factors than in related Pseudomonads with different lifestyles. We highlight the presence of a P. syringae-specific ECF...... sigma factor that is an interesting target for future studies because of its potential role in the adaptation of P. syringae to its specialized phytopathogenic lifestyle....

  17. Using Six Sigma to improve complaints handling

    OpenAIRE

    Patricia Abreu; Sergio Sousa; Isabel Lopes

    2012-01-01

    Currently, companies are in increasingly competitive environment in which customers’ satisfaction and loyalty are vital factors in the success of any organisation. This requires the use of continuous improvement methodologies, such as Six Sigma, which enable companies to improve customer satisfaction and meet their expectations. This paper describes a case study carried out in a company from the automotive industry that has selected a Six Sigma project to respond to a decrease in customer ...

  18. Effective Lagrangian for the linear sigma model at m/sub sigma/ → infinity

    International Nuclear Information System (INIS)

    A new functional integration method is developed for integrating out the heavy chiral scalar field in the linear sigma model to render a finite chiral invariant effective Lagrangian in the one-loop approximation after proper renormalization at m/sub sigma/ → infinity. In addition to the minimal nonlinear sigma model term, the effective Lagrangian also contains a finite chiral invariant quantum correction term with four derivatives

  19. Posttranscriptional osmotic regulation of the sigma(s) subunit of RNA polymerase in Escherichia coli.

    OpenAIRE

    Muffler, A; Traulsen, D D; Lange, R. de; Hengge-Aronis, R

    1996-01-01

    The sigma(s) subunit of RNA polymerase (encoded by the rpoS gene) is a master regulator in a complex regulatory network that governs the expression of many stationary-phase-induced and osmotically regulated genes in Escherichia coli. rpoS expression is itself osmotically regulated by a mechanism that operates at the posttranscriptional level. Cells growing at high osmolarity already exhibit increased levels of sigma(s) during the exponential phase of growth. Osmotic induction of rpoS can be t...

  20. Linezolid resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Pavani Gandham

    2014-08-01

    Full Text Available Linezolid is the only antibiotic available as an oral formulation for resistant staphylococcal infections. It is effective in skin and soft tissue infections, nosocomial pneumonias including VAP, infective endocarditis and MRSA meningitis. It is also effective in the eradication of both nasal and throat colonization of MRSA. Its high bioavailability and post antibiotic effect, ease of switching to oral therapy during its use and the fact that it can be used in patients of all ages, also in patients with liver disease and poor kidney function and its increased effectiveness over glycopeptides makes this drug a precious drug in the treatment of resistant staphylococcal infections. Linezolid resistance in staphylococcus is defined as a linezolid MIC of and #8805;8 mg/L. Reported Linezolid resistance in India and elsewhere is 2-20%. There is clonal dissemination of Linezolid Resistant Staphylococcus aureus (LRSA within or across health care settings which demands continuous surveillance to determine the emergent risk of resistance strains and to establish guidelines for appropriate use. Clinical laboratories should confirm any LRSA preferably by a second method, prior to using linezolid for serious infections. Effective surveillance, more judicious use of this antibiotic, avoiding linezolid usage for empiric therapy in hospital acquired staphylococcus infections, optimization of the pharmacological parameters of the antibiotics in specific clinical situation, decreasing bacterial load by timely surgical debridement or drainage of collections, use of combination therapies would prevent the emergence of resistance to linezolid in staphylococcus aureus. [Int J Res Med Sci 2014; 2(4.000: 1253-1256

  1. Ingested Human Insulin Inhibits the Mosquito NF-κB-Dependent Immune Response to Plasmodium falciparum

    Science.gov (United States)

    Corby-Harris, Vanessa; Green, Gabriel P.; Smithers, Hannah M.; Cheung, Kong W.; Riehle, Michael A.; Luckhart, Shirley

    2012-01-01

    We showed previously that ingested human insulin activates the insulin/IGF-1 signaling pathway in Anopheles stephensi and increases the susceptibility of these mosquitoes to Plasmodium falciparum. In other organisms, insulin can alter immune responsiveness through regulation of NF-κB transcription factors, critical elements for innate immunity that are also central to mosquito immunity. We show here that insulin signaling decreased expression of NF-κB-regulated immune genes in mosquito cells stimulated with either bacterial or malarial soluble products. Further, human insulin suppressed mosquito immunity through sustained phosphatidylinositol 3-kinase activation, since inhibition of this pathway led to decreased parasite development in the mosquito. Together, these data demonstrate that activation of the insulin/IGF-1 signaling pathway by ingested human insulin can alter NF-κB-dependent immunity, and ultimately the susceptibility, of mosquitoes to P. falciparum. PMID:22473605

  2. RRM2 induces NF-κB-dependent MMP-9 activation and enhances cellular invasiveness

    International Nuclear Information System (INIS)

    Ribonucleotide reductase is a dimeric enzyme that catalyzes conversion of ribonucleotide 5'-diphosphates to their 2'-deoxynucleotide forms, a rate-limiting step in the production of 2'-deoxyribonucleoside 5'-triphosphates required for DNA synthesis. The ribonucleotide reductase M2 subunit (RRM2) is a determinant of malignant cellular behavior in a range of human cancers. We examined the effect of RRM2 overexpression on pancreatic adenocarcinoma cellular invasiveness and nuclear factor-κB (NF-κB) transcription factor activity. RRM2 overexpression increases pancreatic adenocarcinoma cellular invasiveness and MMP-9 expression in a NF-κB-dependent manner. RNA interference (RNAi)-mediated silencing of RRM2 expression attenuates cellular invasiveness and NF-κB activity. NF-κB is a key mediator of the invasive phenotypic changes induced by RRM2 overexpression

  3. Six sigma quality for fuel manufacturing

    International Nuclear Information System (INIS)

    It is widely recognized that operational performance in product manufacturing is largely determined by understanding and maintaining process capability. By definition, Six Sigma is a statistical unit of measure reflecting process capability that yields less' than 6.8 defects per million product produced. Statistically, this translates into obtaining a long term manufacturing process capability of ± 4.5 standard deviations about the mean within specification limits. The heart of the Six Sigma program developed by the Six Sigma Academy is what we refer to as the Breakthrough Strategy. This rigorous analytical methodology is the driving force in obtaining world class performance of Six Sigma. The methodology applies statistical and practical tools in resolving a problem or improving a product or process. The application of Six Sigma focuses on attacking process input variables (independent) rather than the output variables. Focusing on these independent variables (temperature, power, force, etc.) and the variation in the end product they create, enables us to get to the root of the problem rather than react to the symptoms of the problem. In this manner we prevent defects from occurring rather than inspecting and monitoring the product. Why the need for such an ambitious program? It is estimated that the cost of failure (rework, scrap, warranties, etc.) can be as high as 15% of sales for companies typically operating at 3-4 sigma. In achieving Six Sigma, costs of failure are typically less than 5%. The thought of reducing business costs while achieving the recognition of being our customer's premier choice provides enormous incentive to reach such status. (author)

  4. Staphylococcus aureus triggered reactive arthritis.

    OpenAIRE

    Siam, A R; M. Hammoudeh

    1995-01-01

    OBJECTIVES--To report two patients who developed reactive arthritis in association with Staphylococcus aureus infection. METHODS--A review of the case notes of two patients. RESULTS--Two adult female patients have developed sterile arthritis in association with Staph aureus infection. The first patient has had two episodes of arthritis; the first followed olecranon bursitis, the second followed infection of a central venous catheter used for dialysis. The second patient developed sterile arth...

  5. Staphylococcus aureus and sore nipples.

    OpenAIRE

    Livingstone, V. H.; Willis, C. E.; Berkowitz, J

    1996-01-01

    OBJECTIVE: To correlate clinical symptoms and signs of sore nipples with the presence of Staphylococcus aureus and to determine the probability of mothers having S aureus-infected nipples when these local symptoms and signs are found. DESIGN: Two cohorts of consecutive patients were enrolled regardless of presenting complaint. A questionnaire was administered to determine the presence and severity of sore nipples. Objective findings on breast examination were documented. A nipple swab was tak...

  6. Isobar Model for Photoproduction of K+Sigma0 and K0Sigma+ on the Proton

    OpenAIRE

    Mart, T.

    2005-01-01

    Kaon photoproductions on the proton gamma p --> K+Sigma0 and gamma p --> K0Sigma+ have been simultaneously analyzed by using isobar models and new SAPHIR data. The result shows that isobar models such as KAON MAID require more resonances in order to explain the data.

  7. Black-box Identity Testing for Low Degree Unmixed $\\Sigma\\Pi\\Sigma\\Pi(k)$ Circuits

    OpenAIRE

    Huang, Jinyu

    2012-01-01

    A $\\Sigma\\Pi\\Sigma\\Pi(k)$ circuit $C=\\sum_{i=1}^kF_i=\\sum_{i=1}^k\\prod_{j=1}^{d_i}f_{ij}$ is unmixed if for each $i\\in[k]$, $F_i=f_{i1}(x_1)... f_{in}(x_n)$, where each $f_{ij}$ is a univariate polynomial given in the sparse representation. In this paper, we give a polynomial time black-box algorithm of identity testing for the low degree unmixed $\\Sigma\\Pi\\Sigma\\Pi(k)$ circuits. In order to obtain the black-box algorithm, we first show that a special class of low degree unmixed $\\Sigma\\Pi\\Si...

  8. Sigma-drop in galaxies and the sigma-metallicity degeneracy

    CERN Document Server

    Koleva, Mina; De Rijcke, Sven

    2008-01-01

    In some galaxies, the central velocity dispersion, sigma, is depressed with respect to the surroundings. This sigma-drop phenomenon may have different physical origins, bearing information about the internal dynamics of the host galaxy. In this article, we stress the importance also of observational artifacts due to the sigma-metallicity degeneracy: when a spectrum of a population is compared with a template of miss-matched metallicity, the velocity dispersion may be wrongly estimated. A sigma-drop may appear in place of a metallicity peak. The discussion is illustrated using VLT/FORS spectra of diffuse elliptical galaxies. Some of the sigma-drop galaxies reported in the literature may be analysis artifacts.

  9. Six Lessons We Learned Applying Six Sigma

    Science.gov (United States)

    Carroll, Napoleon; Casleton, Christa H.

    2005-01-01

    As Chief Financial Officer of Kennedy Space Center (KSC), I'm not only responsible for financial planning and accounting but also for building strong partnerships with the CFO customers, who include Space Shuttle and International Space Station operations as well all who manage the KSC Spaceport. My never ending goal is to design, manage and continuously improve our core business processes so that they deliver world class products and services to the CFO's customers. I became interested in Six Sigma as Christa Casleton (KSC's first Six Sigma Black belt) applied Six Sigma tools and methods to our Plan and Account for Travel Costs Process. Her analysis was fresh, innovative and thorough but, even more impressive, was her approach to ensure ongoing, continuous process improvement. Encouraged by the results, I launched two more process improvement initiatives aimed at applying Six Sigma principles to CFO processes that not only touch most of my employees but also have direct customer impact. As many of you know, Six Sigma is a measurement scale that compares the output of a process with customer requirements. That's straight forward, but demands that you not only understand your processes but also know your products and the critical customer requirements. The objective is to isolate and eliminate the causes of process variation so that the customer sees consistently high quality.

  10. Sigma Model Lagrangian for the Heisenberg Group

    CERN Document Server

    Baaquie, Belal E; Baaquie, Belal E.; Kean, Yim Kok

    2005-01-01

    We study the Lagrangian for a sigma model based on the non-compact Heisenberg group. A unique feature of this model -- unlike the case for compact Lie groups -- is that the definition of the Lagrangian has to be regulated since the trace over the Heisenberg group is otherwise divergent. The resulting theory is a real Lagrangian with a quartic interaction term. After a few non-trivial transformations, the Lagrangian is shown to be equivalent -- at the classical level -- to a complex cubic Lagrangian. A one loop computation shows that the quartic and cubic Lagrangians are equivalent at the quantum level as well. The complex Lagrangian is known to classically equivalent to the SU(2) sigma model, with the equivalence breaking down at the quantum level. An explanation of this well known results emerges from the properties of the Heisenberg sigma model.

  11. Six Sigma Driven Enterprise Model Transformation

    Directory of Open Access Journals (Sweden)

    Raymond Vella

    2009-10-01

    Full Text Available Enterprise architecture methods provide a structured system to understand enterprise activities. However, existing enterprise modelling methodologies take static views of the enterprise and do not naturally lead to a path of improvement during enterprise model transformation. This paper discusses the need for a methodology to facilitate changes for improvement in an enterprise. The six sigma methodology is proposed as the tool to facilitate progressive and continual Enterprise Model Transformation to allow businesses to adapt to meet increased customer expectation and global competition. An alignment of six sigma with phases of GERAM life cycle is described with inclusion of Critical-To-Satisfaction (CTS requirements. The synergies of combining the two methodologies are presented in an effort to provide a more culturally embedded framework for Enterprise Model Transformation that builds on the success of six sigma.

  12. Disc instantons in linear sigma models

    International Nuclear Information System (INIS)

    We construct a linear sigma model for open-strings ending on special Lagrangian cycles of a Calabi-Yau manifold. We illustrate the construction for the cases considered by Aganagic and Vafa (AV). This leads naturally to concrete models for the moduli space of open-string instantons. These instanton moduli spaces can be seen to be intimately related to certain auxiliary boundary toric varieties. By considering the relevant Gelfand-Kapranov-Zelevinsky (GKZ) differential equations of the boundary toric variety, we obtain the contributions to the world volume superpotential on the A-branes from open-string instantons. By using an ansatz due to Aganagic, Klemm and Vafa (AKV), we obtain the relevant change of variables from the linear sigma model to the non-linear sigma model variables--the open-string mirror map. Using this mirror map, we obtain results in agreement with those of AV and AKV for the counting of holomorphic disc instantons

  13. Optimization of Coaching Using Six Sigma

    Directory of Open Access Journals (Sweden)

    Dumitru Colibaba-Evulet

    2011-01-01

    Full Text Available Problem statement: In today’s sports world, coaching and training methods are the subject of intensive competition amongst rivals. Innovative technologies, methodologies and preparation methods are employed to achieve a sustainable competitive advantage. Effective performance measurement, statistical analysis and data based decision taking have been identified as key elements towards efficient performance management. The statistical approach has been emphasized in order to fill the gaps in athlete’s preparation and improve performance. There is need to better connect the dots between the methods of statistical analysis and training and coaching methods used to improve the performance of an athlete or a team. Approach: Industry giants such as Motorola, General Electric and other improved the quality of their products through a statistically driven, six sigma methodology. Literatures in the six sigma performance measurement and improvement in industry, as well as traditional coaching in sports had been extensively reviewed. Research was carried out to establish potential application of six sigma in performance measurement and improvement in sports. Results: The six sigma approach was identified as a new method in measuring, analyzing, improving and analyzing sports performance and two examples were given. The methodology was applied on one example of data collected by authors over years of performance of a basketball team. Direction for further studies in the application of six sigma methodology in team and individual performance coaching and management were also identified. Conclusion: The results of this study determined that there is significant potential to successfully introduce the six sigma methodology of measurement, analysis and improvement in athletic performance. This new direction of analysis involved augmenting the existing traditional methods of coaching and performance management with a powerful methodology

  14. Spin chain sigma models with fermions

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Rafael [Institut de Physique, Universite de Neuchatel, Breguet 1, CH-2000 Neuchatel (Switzerland)]. E-mail: rafael.hernandez@cern.ch; Lopez, [Departamento de Fisica Teorica C-XI and Instituto de Fisica Teorica C-XVI, Universidad Autonoma de Madrid, Cantoblanco, 28049 Madrid (Spain)

    2004-11-01

    The complete one-loop planar dilatation operator of N=4 supersymmetric Yang-Mills is isomorphic to the hamiltonian of an integrable PSU(2,2 vertical bar 4) quantum spin chain. We construct the non-linear sigma models describing the continuum limit of the SU(1|3) and SU(2|3) sectors of the complete N=4 chain. We explicitly identify the spin chain sigma model with the one for a superstring moving in AdS{sub 5} x S{sup 5} with large angular momentum along the five-sphere. (author)

  15. A Lean Six Sigma journey in radiology.

    Science.gov (United States)

    Bucci, Ronald V; Musitano, Anne

    2011-01-01

    The department of radiology at Akron Children's Hospital embarked on a Lean Six Sigma mission as part of a hospital wide initiative to show increased customer satisfaction, reduce employee dissatisfaction and frustration, and decrease costs. Three processes that were addressed were reducing the MRI scheduling back-log, reconciling discrepancies in billing radiology procedures, and implementing a daily management system. Keys to success is that managers provide opportunities to openly communicate between department sections to break down barriers. Executive leaders must be engaged in Lean Six Sigma for the company to be successful. PMID:21793459

  16. A K3 sigma model with : symmetry

    Science.gov (United States)

    Gaberdiel, Matthias R.; Taormina, Anne; Volpato, Roberto; Wendland, Katrin

    2014-02-01

    The K3 sigma model based on the -orbifold of the D 4-torus theory is studied. It is shown that it has an equivalent description in terms of twelve free Majorana fermions, or as a rational conformal field theory based on the affine algebra . By combining these different viewpoints we show that the = (4 , 4) preserving symmetries of this theory are described by the discrete symmetry group : . This model therefore accounts for one of the largest maximal symmetry groups of K3 sigma models. The symmetry group involves also generators that, from the orbifold point of view, map untwisted and twisted sector states into one another.

  17. K0-Sigma+ Photoproduction with SAPHIR

    OpenAIRE

    Bennhold, C.

    1997-01-01

    Preliminary results of the analysis of the reaction p(gamma,K0)Sigma+ are presented. We show the first measurement of the differential cross section and much improved data for the total cross section than previous data. The data are compared with model predictions from different isobar and quark models that give a good description of p(gamma,K+)Lambda and p(gamma,K+)Sigma0 data in the same energy range. Results of ChPT describe the data adequately at threshold while isobar models that include...

  18. 6 Sigma DFSS technique with easy practice

    International Nuclear Information System (INIS)

    This book describes 6 Sigma DFSS technique which is easy to use. These are the titles of the contents : new demand, the reason that DFSS needs, when is DFSS used?, DMAIC and DMADV and the bastion for achievement of 6 sigma, new trouble, chief, Chang's new store, plan on kalguksu development propel, customers are holding the key, CTQ refinement, process capability evaluation, setting goal, finding of conception of optimum design, finding of design element, the last gateway, and it's time for a DFSS!.

  19. "Seis sigma": uma nova cultura empresarial

    OpenAIRE

    Montez, Luís Filipe Duarte

    2011-01-01

    Existe uma miríade de ferramentas para a gestão da qualidade. A grande maioria apareceu no meio industrial, e algumas ultrapassaram barreiras, chegando a todas as áreas de negócio. O processo Seis Sigma é uma ferramenta que se destacou pela sua versatilidade e eficácia, e alcançou uma grande notoriedade na indústria fabril. O discente teve a oportunidade de contactar com o processo Seis Sigma, que evidenciou a sua validade, como ferramenta poderosa em qualquer área de negócio. ...

  20. Prolyl hydroxylase-1 regulates hepatocyte apoptosis in an NF-κB-dependent manner.

    Science.gov (United States)

    Fitzpatrick, Susan F; Fábián, Zsolt; Schaible, Bettina; Lenihan, Colin R; Schwarzl, Thomas; Rodriguez, Javier; Zheng, Xingnan; Li, Zongwei; Tambuwala, Murtaza M; Higgins, Desmond G; O'Meara, Yvonne; Slattery, Craig; Manresa, Mario C; Fraisl, Peter; Bruning, Ulrike; Baes, Myriam; Carmeliet, Peter; Doherty, Glen; von Kriegsheim, Alex; Cummins, Eoin P; Taylor, Cormac T

    2016-06-01

    Hepatocyte death is an important contributing factor in a number of diseases of the liver. PHD1 confers hypoxic sensitivity upon transcription factors including the hypoxia inducible factor (HIF) and nuclear factor-kappaB (NF-κB). Reduced PHD1 activity is linked to decreased apoptosis. Here, we investigated the underlying mechanism(s) in hepatocytes. Basal NF-κB activity was elevated in PHD1(-/-) hepatocytes compared to wild type controls. ChIP-seq analysis confirmed enhanced binding of NF-κB to chromatin in regions proximal to the promoters of genes involved in the regulation of apoptosis. Inhibition of NF-κB (but not knock-out of HIF-1 or HIF-2) reversed the anti-apoptotic effects of pharmacologic hydroxylase inhibition. We hypothesize that PHD1 inhibition leads to altered expression of NF-κB-dependent genes resulting in reduced apoptosis. This study provides new information relating to the possible mechanism of therapeutic action of hydroxylase inhibitors that has been reported in pre-clinical models of intestinal and hepatic disease. PMID:27130823

  1. TRAIL receptor mediates inflammatory cytokine release in an NF-κB-dependent manner

    Institute of Scientific and Technical Information of China (English)

    Wanhu Tang; Weimin Wang; Yaxi Zhang; Shilian Liu; Yanxin Liu; Dexian Zheng

    2009-01-01

    In the present article, we report that DR4 or DR5 overexpression dramatically activates the release of the inflam-matory cytokines IL-8, TNF-α, CCL20, MIP-2 and MIP-1β in an NF-κB-dependent manner in 293T, MDA-MB-231 and HCT-116 cells. We showed that death receptor-mediated signals were extracellular domain-independent, where-as the effect of overexpression of the DR4 intracellular domain was much less potent. The TRADD-TRAF2-NIK-IKKα/β signaling cascade, which plays an essential role in TNF-induced NF-κB activation, was found to be involved in tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-mediated signal transduction. The FADD-caspase signaling pathway, which has been reported to be mostly related to apoptosis, was identified as be-ing essential for DR4 or DR5 overexpression-mediated NF-κB activation and cytokine secretion and crosstalks with the TRADD-TRAF2-NIK-IKKα/β signaling cascade. Furthermore, a DR5 agonistic antibody (AD5-10) triggered the inflammatory cytokine release. These data, together with previous reports, provide strong evidence that TRAIL and TRAIL receptors play an important role in inflammation.

  2. Loss of p53 enhances NF-κB-dependent lamellipodia formation.

    Science.gov (United States)

    Guo, Alvin Kunyao; Hou, Yan Yan; Hirata, Hiroaki; Yamauchi, Shota; Yip, Ai Kia; Chiam, Keng-Hwee; Tanaka, Nobuyuki; Sawada, Yasuhiro; Kawauchi, Keiko

    2014-06-01

    Tumor suppressor p53 prevents tumorigenesis and tumor growth by suppressing the activation of several transcription factors, including nuclear factor-κB (NF-κB) and STAT3. On the other hand, p53 stimulates actin cytoskeleton remodeling and integrin-related signaling cascades. Here, we examined the p53-mediated link between regulation of the actin cytoskeleton and activation of NF-κB and STAT3 in MCF-7 cells and mouse embryonic fibroblasts (MEFs). In the absence of p53, STAT3 was constitutively activated. This activation was attenuated by depleting the expression of p65, a component of NF-κB. Integrin β3 expression and lamellipodia formation were also downregulated by NF-κB depletion. Inhibition of integrin αvβ3, Rac1 or Arp2/3, which diminished lamellipodia formation, suppressed STAT3 activation induced by p53 depletion. These results suggest that loss of p53 leads to STAT3 activation via NF-κB-dependent lamellipodia formation. Our study proposes a novel role for p53 in modulating the actin cytoskeleton through suppression of NF-κB, which restricts STAT3 activation. PMID:24647813

  3. Mycobacterium leprae induces NF-κB-dependent transcription repression in human Schwann cells

    International Nuclear Information System (INIS)

    Mycobacterium leprae, the causative agent of leprosy, invades peripheral nerve Schwann cells, resulting in deformities associated with this disease. NF-κB is an important transcription factor involved in the regulation of host immune antimicrobial responses. We aimed in this work to investigate NF-κB signaling pathways in the human ST88-14 Schwannoma cell line infected with M. leprae. Gel shift and supershift assays indicate that two NF-κB dimers, p65/p50 and p50/p50, translocate to the nucleus in Schwann cells treated with lethally irradiated M. leprae. Consistent with p65/p50 and p50/p50 activation, we observed IκB-α degradation and reduction of p105 levels. The nuclear translocation of p50/p50 complex due to M. leprae treatment correlated with repression of NF-κB-driven transcription induced by TNF-α. Moreover, thalidomide inhibited p50 homodimer nuclear translocation induced by M. leprae and consequently rescues Schwann cells from NF-κB-dependent transcriptional repression. Here, we report for the first time that M. leprae induces NF-κB activation in Schwann cells and thalidomide is able to modulate this activation

  4. Interaction of sigma factor sigmaN with Escherichia coli RNA polymerase core enzyme.

    Science.gov (United States)

    Scott, D J; Ferguson, A L; Gallegos, M T; Pitt, M; Buck, M; Hoggett, J G

    2000-12-01

    The equilibrium binding and kinetics of assembly of the DNA-dependent RNA polymerase (RNAP) sigma(N)-holoenzyme has been investigated using biosynthetically labelled 7-azatryptophyl- (7AW)sigma(N). The spectroscopic properties of such 7AW proteins allows their absorbance and fluorescence to be monitored selectively, even in the presence of high concentrations of other tryptophan-containing proteins. The 7AWsigma(N) retained its biological activity in stimulating transcription from sigma(N)-specific promoters, and in in vitro gel electrophoresis assays of binding to core RNAP from Escherichia coli. Furthermore, five Trp-->Ala single mutants of sigma(N) were shown to support growth under conditions of nitrogen limitation, and showed comparable efficiency in activating the sigma(N)-dependent nifH promoter in vivo, indicating that none of the tryptophan residues were essential for activity. The equilibrium binding of 7AWsigma(N) to core RNAP was examined by analytical ultracentrifugation. In sedimentation equilibrium experiments, absorbance data at 315 nm (which reports selectively on the distribution of free and bound 7AWsigma(N)) established that a 1:1 complex was formed, with a dissociation constant lower than 2 microM. The kinetics of the interaction between 7AWsigma(N) and core RNAP was investigated using stopped-flow spectrofluorimetry. A biphasic decrease in fluorescence intensity was observed when samples were excited at 280 nm, whereas only the slower of the two phases was observed at 315 nm. The kinetic data were analysed in terms of a mechanism in which a fast bimolecular association of sigma(N) with core RNAP is followed by a relatively slow isomerization step. The consequences of these findings on the competition between sigma(N) and the major sigma factor, sigma(70), in Escherichia coli are discussed. PMID:11085949

  5. The Scientific Underpinning of Lean Six Sigma

    NARCIS (Netherlands)

    R.J.M.M. Does; J. de Mast; H. de Koning; S. Bisgaard

    2007-01-01

    The twentieth century saw an incredible development of professional organizations. The impact of technological advances is obvious, but besides these, innovations in management structures and methods have resulted in the highly productive organizations of today. Lean Six Sigma is not revolutionary.

  6. Sigma-models and Homotopy Algebras

    CERN Document Server

    Zeitlin, Anton M

    2015-01-01

    We review the relation between homotopy algebras of conformal field theory and geometric structures arising in sigma models. In particular we formulate conformal invariance conditions, which in the quasi-classical limit are Einstein equations with extra fields, as generalized Maurer-Cartan equations.

  7. How Six Sigma Methodology Improved Doctors' Performance

    Science.gov (United States)

    Zafiropoulos, George

    2015-01-01

    Six Sigma methodology was used in a District General Hospital to assess the effect of the introduction of an educational programme to limit unnecessary admissions. The performance of the doctors involved in the programme was assessed. Ishikawa Fishbone and 5 S's were initially used and Pareto analysis of their findings was performed. The results…

  8. Improving Learning Outcome Using Six Sigma Methodology

    Science.gov (United States)

    Tetteh, Godson A.

    2015-01-01

    Purpose: The purpose of this research paper is to apply the Six Sigma methodology to identify the attributes of a lecturer that will help improve a student's prior knowledge of a discipline from an initial "x" per cent knowledge to a higher "y" per cent of knowledge. Design/methodology/approach: The data collection method…

  9. Need of Six Sigma in Education

    Science.gov (United States)

    Mehrotra, Dheeraj

    2007-01-01

    The marching trend of the new economic order has generated a new capsule of SIX SIGMA as a unified approach to process excellence. The tests reveal that it has transformed some of the most successful companies in the world like Motorola, GE etc. It is activated as an approach to aiming at the target by changing the culture of a company, involving…

  10. Evidence that RpoS (sigmaS) in Borrelia burgdorferi is controlled directly by RpoN (sigma54/sigmaN).

    Science.gov (United States)

    Smith, Alexandra H; Blevins, Jon S; Bachlani, Gulnaz N; Yang, Xiaofeng F; Norgard, Michael V

    2007-03-01

    The alternative sigma factor (RpoN-RpoS) pathway controls the expression of key virulence factors in Borrelia burgdorferi. However, evidence to support whether RpoN controls rpoS directly or, perhaps, indirectly via a transactivator has been lacking. Herein we provide biochemical and genetic evidence that RpoN directly controls rpoS in B. burgdorferi. PMID:17158681

  11. Extracytoplasmic function sigma factors in Pseudomonas syringae

    DEFF Research Database (Denmark)

    Kiil, Kristoffer; Oguiza, J.A.; Ussery, D.W.

    2005-01-01

    Genome analyses of the plant pathogens Pseudomonas syringae pv. tomato DC3000, pv. syringae B728a and pv. phaseolicola 1448A reveal fewer extracytoplasmic function (ECF) sigma factors than in related Pseudomonads with different lifestyles. We highlight the presence of a P. syringae-specific ECF...

  12. Sigma factors and promoters in Corynebacterium glutamicum

    Czech Academy of Sciences Publication Activity Database

    Pátek, Miroslav; Nešvera, Jan

    2011-01-01

    Roč. 154, 2-3 (2011), s. 101-113. ISSN 0168-1656 R&D Projects: GA ČR GC204/09/J015 Institutional research plan: CEZ:AV0Z50200510 Keywords : Corynebacterium glutamicum * Sigma factors * Promoters Subject RIV: EE - Microbiology, Virology Impact factor: 3.045, year: 2011

  13. The science of Six Sigma in hospitals.

    Science.gov (United States)

    Guinane, Carole S; Davis, Noreen H

    2004-01-01

    Six Sigma applied to hospital processes and services can lead to breakthrough improvements, near-perfect outcomes, and zero defects. It is wise to consider this aspect of quality science as part of an overall Total Quality Management program. Senior leadership support and involvement is critical to the success of this strategy. PMID:15604839

  14. The response regulator RssB controls stability of the sigma(S) subunit of RNA polymerase in Escherichia coli.

    OpenAIRE

    Muffler, A; Fischer, D; Altuvia, S; Storz, G.; Hengge-Aronis, R

    1996-01-01

    The rpoS-encoded sigma(S) subunit of RNA polymerase is a central regulator in a regulatory network that governs the expression of many stationary phase-induced and osmotically regulated genes in Escherichia coli. sigma(S) is itself induced under these conditions due to an increase in rpoS transcription (only in rich media) and rpoS translation as well as a stabilization of sigma(S) protein which in growing cells is subject to rapid turnover. We demonstrate here that a response regulator, RssB...

  15. Collagen binding to Staphylococcus aureus

    International Nuclear Information System (INIS)

    Staphylococcus aureus can bind soluble collagen in a specific, saturable manner. We have previously shown that some variability exists in the degree of collagen binding between different strains of heat-killed, formaldehyde-fixed S. aureus which are commercially available as immunologic reagents. The present study demonstrates that live S. aureus of the Cowan 1 strain binds amounts of collagen per organism equivalent to those demonstrated previously in heat-killed, formaldehyde-fixed bacteria but has an affinity over 100 times greater, with Kd values of 9.7 X 10(-11) M and 4.3 X 10(-8) M for live and heat-killed organisms, respectively. Studies were also carried out with S. aureus killed by ionizing radiation, since this method of killing the organism seemed less likely to alter the binding moieties on the surface than did heat killing. Bacteria killed by exposure to gamma radiation bound collagen in a manner essentially indistinguishable from that of live organisms. Binding of collagen to irradiated cells of the Cowan 1 strain was rapid, with equilibrium reached by 30 min at 22 degrees C, and was fully reversible. The binding was not inhibited by fibronectin, fibrinogen, C1q, or immunoglobulin G, suggesting a binding site for collagen distinct from those for these proteins. Collagen binding was virtually eliminated in trypsin-treated organisms, indicating that the binding site has a protein component. Of four strains examined, Cowan 1 and S. aureus ATCC 25923 showed saturable, specific binding, while strains Woods and S4 showed a complete lack of binding. These results suggest that some strains of S. aureus contain high-affinity binding sites for collagen. While the number of binding sites per bacterium varied sixfold in the two collagen-binding strains, the apparent affinity was similar

  16. Host-adaptive evolution of Staphylococcus aureus

    OpenAIRE

    Lowder, Bethan Victoria

    2011-01-01

    Staphylococcus aureus is a notorious human pathogen associated with severe nosocomial and community-acquired infections. In addition, S. aureus is a major cause of animal diseases including skeletal infections of poultry and bovine and ovine mastitis, which are a large economic burden on the broiler chicken and dairy farming industries. The population structure of S. aureus associated with humans has been well studied. However, despite the prevalence of S. aureus infections in ...

  17. Quark and sigma mass dependence of nucleon properties from linear sigma model

    International Nuclear Information System (INIS)

    The sensitivity of static nucleon properties (magnetic moment, axial-vector coupling constant gA, pion–nucleon coupling constant gπNN and sigma commutator term σπN) to the quark and sigma masses have been investigated in the mean-field approximation. We have solved the field equations in the mean-field approximation with different sets of model parameters. Good results have been obtained in comparison with the other models and experimental data. (author)

  18. Analysis of the vertexes $\\Xi_Q^*\\Xi'_Q V$, $\\Sigma_Q^*\\Sigma_Q V$ and radiative decays $\\Xi_Q^*\\to \\Xi'_Q \\gamma$, $\\Sigma_Q^*\\to \\Sigma_Q \\gamma$

    OpenAIRE

    Wang, Zhi-Gang

    2009-01-01

    In this article, we study the vertexes $\\Xi_Q^*\\Xi'_Q V$ and $\\Sigma_Q^* \\Sigma_Q V$ with the light-cone QCD sum rules, then assume the vector meson dominance of the intermediate $\\phi(1020)$, $\\rho(770)$ and $\\omega(782)$, and calculate the radiative decays $\\Xi_Q^*\\to \\Xi'_Q \\gamma$ and $\\Sigma_Q^*\\to \\Sigma_Q \\gamma$.

  19. Genome Sequence of the Clinical Isolate Staphylococcus aureus subsp. aureus Strain UAMS-1

    OpenAIRE

    Sassi, Mohamed; Sharma, Deepak; Brinsmade, Shaun ,; Felden, Brice; Augagneur, Yoann

    2015-01-01

    We report here the draft genome sequence of Staphylococcus aureus subsp. aureus strain UAMS-1. UAMS-1 is a virulent oxacillin-susceptible clinical isolate. Its genome is composed of 2,763,963 bp and will be useful for further gene expression analysis using RNA sequencing (RNA-seq) technology. S taphylococcus aureus is an opportunistic human bacterial pathogen responsible for nosocomial and community-associated infections. S. aureus subsp. aureus strain UAMS-1 was originally isolated from the ...

  20. Effect of sigma factor S (sigmaS on the stability of penicillin-binding protein 3 (PBP3 of Escherichia colt K12

    Directory of Open Access Journals (Sweden)

    Rosane S. Machado

    1996-01-01

    Full Text Available The stability of penicillin-binding protein 3 (PBP3, a cell septum synthesizing protein, was analyzed at different incubation temperatures in three Escherichia coli K12 strains carrying a PBP3-overproducing plasmid. The stability of PBP3 was significantly reduced in stationary phase cells shifted to 42°C for 4 h, compared to samples incubated at 28 or 37°C. The half-life of PBP3 in the C600 strain was 60 min at 42°C, while samples incubated at 28 or 37°C had PBP3 half-lives greater than 4 h. Analysis of the PBP3 content in mutants deficient in rpoS (coding for the stationary phase sigma factor, sigmaS and rpoH (coding for the heat shock sigma factor, sigma32 genes after shift to 42°C showed that stability of the protein was controlled by sigmaS but not by sigma32. These results suggest that control of the PBP3 levels in E. coli K12 is through a post-transcriptional mechanism regulated by the stationary phase regulon. We demonstrated that stability of PBP3 in E. coli K12 involves degradation of the protein. Moreover, we observed that incubation of cells at 42°C significantly reduces the stability of PBP3 in early stationary phase cells in a process controlled by sigmaS.

  1. Incorporating Six Sigma Methodology Training into Chemical Engineering Education

    Science.gov (United States)

    Dai, Lenore L.

    2007-01-01

    Six Sigma is a buzz term in today's technology and business world and there has been increasing interest to initiate Six Sigma training in college education. We have successfully incorporated Six Sigma methodology training into a traditional chemical engineering course, Engineering Experimentation, at Texas Tech University. The students have…

  2. Peripheral Production of Sigmas in Proton Proton Collisions

    OpenAIRE

    Kisslinger, Leonard S.; Ma, Wei-hsing; Shen, Pengnian

    2000-01-01

    The Pomeron, which dominates high energy elastic and diffractive hadronic processes, must be largely gluonic in nature. We use a recent picture of a scalar glueball/sigma system with coupling of the sigma to glue determined from experiment to predict strong peripheral sigma production seen in the p p $\\pi^o\\pi^o$ final state.

  3. Operational excellence (six sigma) philosophy: Application to software quality assurance

    Energy Technology Data Exchange (ETDEWEB)

    Lackner, M.

    1997-11-01

    This report contains viewgraphs on operational excellence philosophy of six sigma applied to software quality assurance. This report outlines the following: goal of six sigma; six sigma tools; manufacturing vs administrative processes; Software quality assurance document inspections; map software quality assurance requirements document; failure mode effects analysis for requirements document; measuring the right response variables; and questions.

  4. Variation in the TonB-dependent Outer-Membrane Proteins in Plant-Associated Strains of Pseudomonas fluorescens

    Science.gov (United States)

    Nutrient acquisition is key to the ecological fitness of environmental bacteria such as Pseudomonas fluorescens and TonB-dependent outer-membrane proteins are important components of the cellular machinery for the uptake of substrates from the environment. Genomic sequences of ten strains of plant-a...

  5. Diversity of TonB-dependent outer-membrane proteins in plant-associated strains of Pseudomonas fluorescens

    Science.gov (United States)

    Genomic sequences of ten strains of plant-associated Pseudomonas spp. were surveyed for the presence of TonB-dependent outer-membrane proteins (TBDPs), which function in the uptake of substrates from the environment by many Gram-negative bacteria. The ten strains, representing P. fluorescens, P. ch...

  6. ppGpp and DksA likely regulate the activity of the extracytoplasmic stress factor sigmaE in Escherichia coli by both direct and indirect mechanisms.

    Science.gov (United States)

    Costanzo, Alessandra; Nicoloff, Herve; Barchinger, Sarah E; Banta, Amy B; Gourse, Richard L; Ades, Sarah E

    2008-02-01

    One of the major signalling pathways responsible for intercompartmental communication between the cell envelope and cytoplasm in Escherichia coli is mediated by the alternative sigma factor, sigmaE. sigmaE has been studied primarily for its role in response to the misfolding of outer membrane porins. This response is essentially reactionary; cells are stressed, porin folding is disrupted, and the response is activated. sigmaE can also be activated following starvation for a variety of nutrients by the alarmone ppGpp. This response is proactive, as sigmaE is activated in the absence of any obvious damage to the cell envelope sensed by the stress signalling pathway. Here we examine the mechanism of regulation of sigmaE by ppGpp. ppGpp has been proposed to activate at least two alternative sigma factors, sigmaN and sigmaS, indirectly by altering the competition for core RNA polymerase between the alternative sigma factors and the housekeeping sigma factor, sigma70. In vivo experiments with sigmaE are consistent with this model. However, ppGpp and its cofactor DksA can also activate transcription by EsigmaEin vitro, suggesting that the effects of ppGpp on sigmaE activity are both direct and indirect. PMID:18086212

  7. Non-compact nonlinear sigma models

    Science.gov (United States)

    de Rham, Claudia; Tolley, Andrew J.; Zhou, Shuang-Yong

    2016-09-01

    The target space of a nonlinear sigma model is usually required to be positive definite to avoid ghosts. We introduce a unique class of nonlinear sigma models where the target space metric has a Lorentzian signature, thus the associated group being non-compact. We show that the would-be ghost associated with the negative direction is fully projected out by 2 second-class constraints, and there exist stable solutions in this class of models. This result also has important implications for Lorentz-invariant massive gravity: There exist stable nontrivial vacua in massive gravity that are free from any linear vDVZ-discontinuity and a Λ2 decoupling limit can be defined on these vacua.

  8. Non-compact nonlinear sigma models

    CERN Document Server

    de Rham, Claudia; Zhou, Shuang-Yong

    2015-01-01

    The target space of a nonlinear sigma model is usually required to be positive definite to avoid ghosts. We introduce a unique class of nonlinear sigma models where the target space metric has a Lorentzian signature, thus the associated group being non-compact. We show that the would-be ghost associated with the negative direction is fully projected out by 2 second-class constraints, and there exist stable solutions in this class of models. This result also has important implications for Lorentz--invariant massive gravity: There exist stable nontrivial vacua in massive gravity that are free from any linear vDVZ--discontinuity and a $\\Lambda_2$ decoupling limit can be defined on these vacua.

  9. Applying Six Sigma in foodservice organizations

    OpenAIRE

    Kivela, Jaksa; Kagi, Jacky

    2009-01-01

    This study investigated how a large foodservice organization successfully adopted the Six Sigma quality system from other industry applications in their foodservice environment. In addition, the study explored how different levels of the organization had contributed to the application and the perceived importance of such system within the organization. Review of the recent foodservice lite-rature suggested that quality service research is important because it is directly linked to customer sa...

  10. Phantom Black Holes and Sigma Models

    OpenAIRE

    Azreg-Aïnou, Mustapha; Clément, Gérard; Fabris, Júlio C.; Rodrigues, Manuel E.

    2011-01-01

    We construct static multicenter solutions of phantom Einstein-Maxwell-dilaton theory from null geodesics of the target space, leading to regular black holes without spatial symmetry for certain discrete values of the dilaton coupling constant. We also discuss the three-dimensional gravitating sigma models obtained by reduction of phantom Einstein-Maxwell, phantom Kaluza-Klein and phantom Einstein-Maxwell-dilaton-axion theories. In each case, we generate by group transformations phantom charge...

  11. Six Sigma Driven Enterprise Model Transformation

    OpenAIRE

    Raymond Vella; Sekhar Chattopadhyay; John P.T. Mo

    2009-01-01

    Enterprise architecture methods provide a structured system to understand enterprise activities. However, existing enterprise modelling methodologies take static views of the enterprise and do not naturally lead to a path of improvement during enterprise model transformation. This paper discusses the need for a methodology to facilitate changes for improvement in an enterprise. The six sigma methodology is proposed as the tool to facilitate progressive and continual Enterprise Model Transform...

  12. Six Sigma Implementation at Bharti Infotel

    OpenAIRE

    Archana Shukla; Srinivasan, R.

    2007-01-01

    Bharti Airtel Limited was a leading private sector provider of telecommunication services in India, with a customer base of 8.73 million as of July 2004. The company had two branch companies — Bharti Infotel (that dealt with fixed line, long distance, and enterprise services) and Bharti Cellular (that dealt with mobile telephone services). This case is about the six sigma implementation at Bharti Infotel.The case briefly discusses the business imperatives in the fast changing Indian telecommu...

  13. Staphylococcus aureus and hand eczema severity

    DEFF Research Database (Denmark)

    Haslund, P; Bangsgaard, N; Jarløv, J O;

    2009-01-01

    BACKGROUND: The role of bacterial infections in hand eczema (HE) remains to be assessed. OBJECTIVES: To determine the prevalence of Staphylococcus aureus in patients with HE compared with controls, and to relate presence of S. aureus, subtypes and toxin production to severity of HE. METHODS......: Bacterial swabs were taken at three different visits from the hand and nose in 50 patients with HE and 50 controls. Staphylococcus aureus was subtyped by spa typing and assigned to clonal complexes (CCs), and isolates were tested for exotoxin-producing S. aureus strains. The Hand Eczema Severity Index...... was used for severity assessment. RESULTS: Staphylococcus aureus was found on the hands in 24 patients with HE and four controls (P aureus was found to be related to increased severity of the eczema (P aureus types on the hands...

  14. Planetary companion in K giant Sigma Persei

    CERN Document Server

    Lee, Byeong-Cheol; Park, Myeong-Gu; Mkrtichian, David E; Jeong, Gwanghui; Kim, Kang-Min; Valyavin, Gennady

    2014-01-01

    We report the detection of an exoplanet candidate in orbit around sigma Persei from a radial velocity (RV) survey. The system exhibits periodic RV variations of 579.8 +/- 2.4 days. The purpose of the survey is to search for low-amplitude and long-period RV variations in giants and examine the origin of the variations using the fiber-fed Bohyunsan Observatory Echelle Spectrograph installed at the 1.8-m telescope of Bohyunsan Optical Astronomy Observatory in Korea. We present high-accuracy RV measurements of sigma Per made from December 2003 to January 2014. We argue that the RV variations are not related to the surface inhomogeneities but instead a Keplerian motion of the planetary companion is the most likely explanation. Assuming a stellar mass of 2.25 +/- 0.5 M_Sun, we obtain a minimum planetary companion mass of 6.5 +/- 1.0 M_Jup, with an orbital semi-major axis of 1.8 +/- 0.1 AU, and an eccentricity of 0.3 +/- 0.1 around sigma Per.

  15. Sigma-model representation of gauge theories

    International Nuclear Information System (INIS)

    A new formulation of gauge theories in terms of the eight-dimensional nonlinear sigma-model is presented. The basic quantity is the principal chiral field b(x,y) with values in the relevant group algebra, xsub(μ) being identified as the usual Minkowski 4-coordinate. The Yang-Mills field is defined as bsub(μ)(x). The higher components in the y-expansion of b(x,y) are shown to be removable at the expense of bsub(μ)(x) by imposing on b(x,Y) certain covariant constraints. This procedure results in the ''string'' representation for b(x,y) in terms of the path-ordered integral of bsub(μ)(x) along a fixed path between points (x+y),x. The standard source-free Yang-Mills equations are found to be equivalent to the continuity equation (with respect to y-differentiation) for the Cartan form associated with some particular b(x, y). The striking analogy with ordinary sigma-models suggests that the symmetric, gauge-invariant phase of the Yang-Mills theory may be described most adequately within the corresponding eight-dimensional linear sigma-model

  16. Sigma meson production in proton-nucleus collisions

    International Nuclear Information System (INIS)

    The sigma meson production is investigated in p + 40Ca and p + 208Pb at the incident energy 1.5 GeV within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A dependence of the sigma production that the increase of A is followed by an increase of the production cross section. We find that the sigma meson production is strongly medium dependent and the produced sigma mesons decaying in a dense medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs, which did not suffer absorption by the surrounding nucleons. It is pointed out that the ratio of measured sigma cross-sections as a function of the sigma invariant-mass from various reactions is a good probe to explore the existence of the sigma meson in dense nuclear environment. (author)

  17. Six sigma and lean production adoption in a manufacturing company

    Directory of Open Access Journals (Sweden)

    Alisson Christian Scheller

    2014-11-01

    Full Text Available The connection among Lean Production with Six Sigma originated the Lean Six Sigma methodology, focused on processes variation and waste reduction. This methodology was developed on different ways in the companies and there is no consensus over its structure and its implementation. In this context, this paper aims to identify and analyze the main characteristics on the adoption and integration of Lean Six Sigma methodology through a case study conducted in a manufacturing company that adopts lean production and six sigma. The results show two important aspects of the Lean Six Sigma methodology. One of them is the adoption of the value stream mapping as a central tool on Lean Six Sigma. The other is the use of DMAIC for improvements actions. The study indicates that despite the difficulties on Lean Six Sigma implementation, the methodology offers benefits to the company that adopts it in the suitable way.

  18. K^0 pi^0 Sigma^+ and K^*0 Sigma^+ photoproduction off the proton

    CERN Document Server

    Nanova, M; Bantes, B; Bartholomy, O; Bayadilov, D; Beck, R; Beloglasov, Yu A; Castelijns, R; Credé, V; Dutz, H; Ehmanns, A; Elsner, D; Essig, K; Ewald, R; Fabry, I; Fornet-Ponse, K; Fuchs, M; Funke, C; Gothe, R; Gregor, R; Gridnev, A B; Gutz, E; Hoffmeister, P; Horn, I; Jaegle, I; Junkersfeld, J; Kalinowsky, H; Kammer, S; Kleber, V; Klein, Frank; Klein, Friedrich; Klempt, E; Konrad, M; Kotulla, M; Krusche, B; Lang, M; Langheinrich, J; Löhner, H; Lopatin, I V; Lotz, J; Lugert, S; Menze, D; Messchendorp, J G; Mertens, T; Metag, V; Morales, C; Novinski, D V; Novotny, R; Ostrick, M; Pant, L M; Van Pee, H; Pfeiffer, M; Radkov, A; Roy, A; Schadmand, S; Schmidt, C; Schmieden, H; Schoch, B; Shende, S V; Sokhoyan, V; Sule, A; Sumachev, V V; Szczepanek, T; Thoma, U; Trnka, D; Varma, R; Walther, D; Weinheimer, C; Wendel, C

    2008-01-01

    The exclusive reactions $\\gamma p \\to K^{*0} \\Sigma^+(1189)$ and $\\gamma p \\to K^{0} \\pi^{0}\\Sigma^+(1189)$, leading to the p 4$\\pi^{0}$ final state, have been measured with a tagged photon beam for incident energies from threshold up to 2.5 GeV. The experiment has been performed at the tagged photon facility of the ELSA accelerator (Bonn). The Crystal Barrel and TAPS detectors were combined to a photon detector system of almost 4$\\pi$ geometrical acceptance. Differential and total cross sections are reported. At energies close to the threshold, a flat angular distribution has been observed for the reaction $\\gamma p\\to K^{0} \\pi^{0}\\Sigma^+$ suggesting dominant s-channel production. $\\Sigma^*(1385)$ and higher lying hyperon states have been observed. An enhancement in the forward direction in the angular distributions of the reaction $\\gamma p \\to K^{*0}\\Sigma^+$ indicates a $t$-channel exchange contribution to the reaction mechanism. The experimental data are in reasonable agreement with recent theoretical ...

  19. First Observation of Heavy Baryons \\Sigma_b and \\Sigma_b^*

    CERN Document Server

    Aaltonen, T; Adelman, J; Affolder, T; Akimoto, T; Albrow, M G; Amerio, S; Amidei, D; Anastassov, A; Anikeev, K; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P H; Bedeschi, F; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bölla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, Yu A; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carillo, S; Carlsmith, D; Carosi, R; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, I; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Cilijak, M; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Coca, M; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca-Almenar, C; Cuevas-Maestro, J; Culbertson, R; Cully, J C; Da Ronco, S; Datta, M; D'Auria, S; Davies, T; Dagenhart, D; De Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'Orso, Mauro; Delli Paoli, F; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Dorr, C; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, I; Fedorko, W T; Feild, R G; Feindt, M; Fernández, J P; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; García, J E; Garberson, F; Garfinkel, A F; Gay, C; Gerberich, H; Gerdes, D; Giagu, S; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Giurgiu, G; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Goldstein, J; Golossanov, A; Gómez, G; Gómez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Group, R C; Grundler, U; Guimarães da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hidas, D; Hill, C S; Hirschbuehl, D; Höcker, A; Holloway, A; Hou, S; Houlden, M; Hsu, S C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jang, D; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Karchin, P E; Kato, Y; Kemp, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraan, A C; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; LeCompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lu, R S; Lucchesi, D; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; MacQueen, D; Madrak, R; Maeshima, K; Makhoul, K; Mäki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marginean, R; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martinez-Ballarin, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Matsunaga, H; Mattson, M E; Mazini, R; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtälä, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyamoto, A; Moed, S; Moggi, N; Mohr, B; Moon, C S; Moore, R; Morello, M; Movilla-Fernández, P A; Mülmenstädt, J; Mukherjee, A; Müller, T; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Österberg, K; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, Aldo L; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P B; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Salto, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savard, P; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyrla, A; Shalhout, S Z; Shapiro, M D; Shears, T G; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakian, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Söderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; Staveris-Polykalas, A; Saint-Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Tesarek, R J; Thom, J; Thompson, A S; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tsuno, S; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; Van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veramendi, G; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Vollrath, I; Volobuev, I P; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner, J; Wagner, W; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zhou, J; Zucchelli, S

    2007-01-01

    We report an observation of new bottom baryons produced in proton-antiproton collisions at the Tevatron. Using 1.1 fb^{-1} of data collected by the CDF II detector, we observe four \\Lambda_b^0\\pi^{\\pm} resonances in the fully reconstructed decay mode \\Lambda_b^0 \\to \\Lambda_c^+ \\pi^-, where \\Lambda_c^+ \\to p K^- \\pi^+. We interpret these states as the \\Sigma_b^{(*)\\pm} baryons and measure their masses to be: m_{\\Sigma_b^+} = 5807.8^{+2.0}_{-2.2} (stat.) \\pm 1.7 (syst.) MeV/c^2 m_{\\Sigma_b^-} = 5815.2 \\pm 1.0 (stat.) \\pm 1.7 (syst.) MeV/c^2 m_{\\Sigma_b^{*+}} = 5829.0^{+1.6}_{-1.8} (stat.) ^{+1.7}_{-1.8} (syst.) MeV/c^2 m_{\\Sigma_b^{*-}} = 5836.4 \\pm 2.0 (stat.) ^{+1.8}_{-1.7} (syst.) MeV/c^2

  20. Genome sequence of type strain of Staphylococcus aureus subsp. aureus

    OpenAIRE

    Kim, Bong-Soo; Yi, Hana; Chun, Jongsik; Cha, Chang-Jun

    2014-01-01

    Background Staphylococcus aureus is a pathogen that causes food poisoning and community-associated infection with antibiotic resistance. This species is an indigenous intestinal microbe found in infants and not found in adult intestine. The relatively small genome size and rapid evolution of antibiotic resistance genes in the species have been drawing an increasing attention in public health. To extend our understanding of the species and use the genome data for comparative genomic studies, w...

  1. Virulence properties of Pseudomonas aeruginosa lacking the extreme-stress sigma factor AlgU (sigmaE).

    Science.gov (United States)

    Yu, H; Boucher, J C; Hibler, N S; Deretic, V

    1996-07-01

    A discerning feature of Pseudomonas aeruginosa strains causing chronic endobronchial infections in cystic fibrosis is their conversion into the mucoid, exopolysaccharide alginate-overproducing phenotype. This morphologically prominent change is caused by mutations which upregulate AlgU (sigma(E)), a novel extreme-stress sigma factor with functional equivalents in gram-negative organisms. In this work, we investigated the role of algU in P. aeruginosa sensitivity to reactive oxygen intermediates, killing by phagocytic cells, and systemic virulence of this bacterium. Inactivation of algU in P. aeruginosa PA01 increased its susceptibility to killing by chemically or enzymatically generated halogenated reactive oxygen intermediates and reduced its survival in bactericidal assays with J774 murine macrophages and human neutrophils. Surprisingly, inactivation of algU caused increased systemic virulence of P. aeruginosa in mouse models of acute infection. The increased lethality of the algU-deficient strain was also observed in the endotoxin-resistant C3H/HeJ mice. Only minor differences between algU+ and algU mutant cells in their sensitivity to human serum were observed, and no differences in their lipopolysaccharide profiles were detected. Intriguingly, while inactivation of algU downregulated five polypeptides it also upregulated the expression of seven polypeptides as determined by two-dimensional gel analyses, suggesting that algU plays both a positive and a negative role in gene expression in P. aeruginosa. While the observation that algU inactivation increases systemic virulence in P. aeruginosa requires further explanation, this phenomenon contrasts with the apparent selection for strains with upregulated AlgU during colonization of the cystic fibrosis lung and suggests opposing roles for this system in chronic and acute infections. PMID:8698507

  2. A comparison of simulated precipitation by hybrid isentropic-sigma and sigma models

    Science.gov (United States)

    Johnson, Donald R.; Zapotocny, Tom H.; Reames, Fred M.; Wolf, Bart J.; Pierce, R. B.

    1993-01-01

    Simulations of dry and moist baroclinic development from 10- and 22-layer hybrid isentropic-sigma coordinate models are compared with those from 11-, 27-, and 35-layer sigma coordinate models. The ability of the models to transport water vapor and simulate equivalent potential temperature is examined. Predictions of the timing, location, and amount of precipitation are compared. Several analytical distributions of water vapor are specified initially. It is shown that when the relative humidity is vertically uniform through a substantial extent of the atmosphere, all the models produce very similar precipitation distributions. However, when water vapor is confined to relatively shallow layers, the ability of the sigma coordinate models to simulate the timing, location, and amount of precipitation is severely compromised.

  3. Accumulation of sigmaS due to enhanced synthesis and decreased degradation in acidic phospholipid-deficient Escherichia coli cells.

    Science.gov (United States)

    Uchiyama, Junji; Sasaki, Yu; Nagahama, Hideki; Itou, Aya; Matsuoka, Satoshi; Matsumoto, Kouji; Hara, Hiroshi

    2010-06-01

    The Escherichia coli pgsA3 mutation, which causes deficiency in acidic phospholipids, leads to a significant accumulation of sigma(S). This accumulation is partly accounted for by the higher transcription level of rpoS; however, it has also been suggested that the cells accumulate sigma(S) post-transcriptionally. We found that the level of the small regulatory RNA RprA, which is involved in the promotion of rpoS translation, is higher in pgsA3 cells than in pgsA(+) cells. Induction of altered rpoS mRNA that does not depend on RprA in pgsA(+) cells did not increase the level of sigma(S) to the high level observed in pgsA3 cells, suggesting post-translational sigma(S) accumulation in the latter. The mRNA levels of clpX and clpP, whose products form a ClpXP protease that degrades sigma(S), were much reduced in pgsA3 cells. Consistent with the reduced mRNA levels, the half-life of sigma(S) in pgsA3 cells was much longer than in pgsA(+) cells, indicating that downregulation of the degradation is a major cause for the high sigma(S) content. We show that the downregulation can be partially attributed to activated CpxAR in the mutant cells, which causes repression of rpoE on whose gene product the expression of clpPX depends. PMID:20455949

  4. Lean Six Sigma Projects and IT

    Institute of Scientific and Technical Information of China (English)

    Gyula Mosoni; Chee-Cheng Chen

    2013-01-01

    Lean Six Sigma operations capitalizing on the benefits of using IT follow the same principle as other process improvement methods where the main goals are maximizing the value, eliminating waste, and minimizing defects. If the transformation has been planned in the appropriate way, customer satisfaction should become higher (e.g., easier to use the web site, safer payment process, shorter waiting time)and the operations will generally be smoother; as a result, the company should be on track to becoming more profitable.

  5. Explicit BCJ numerators of nonlinear sigma model

    CERN Document Server

    Du, Yi-Jian

    2016-01-01

    In this paper, we investigate the color-kinematics duality in nonlinear sigma model (NLSM). We present explicit polynomial expressions for the kinematic numerators (BCJ numerators). The calculation is done separately in two parametrization schemes of the theory using Kawai-Lewellen-Tye relation inspired technique, both lead to polynomial numerators. We summarize the calculation in each case into a set of rules that generates BCJ numerators for all multilplicities. In Cayley parametrization we find the numerator is described by a particularly simple formula solely in terms of momentum kernel.

  6. F-theory and linear sigma models

    CERN Document Server

    Bershadsky, M; Greene, Brian R; Johansen, A; Lazaroiu, C I

    1998-01-01

    We present an explicit method for translating between the linear sigma model and the spectral cover description of SU(r) stable bundles over an elliptically fibered Calabi-Yau manifold. We use this to investigate the 4-dimensional duality between (0,2) heterotic and F-theory compactifications. We indirectly find that much interesting heterotic information must be contained in the `spectral bundle' and in its dual description as a gauge theory on multiple F-theory 7-branes. A by-product of these efforts is a method for analyzing semistability and the splitting type of vector bundles over an elliptic curve given as the sheaf cohomology of a monad.

  7. X-Sigma-Rho and Market Efficiency

    Directory of Open Access Journals (Sweden)

    G. Glenn Baigent

    2014-04-01

    Full Text Available Menchero and Davis (2011 define X-Sigma-Rho as a risk metric that shows the marginal contribution to risk when a security is added to a portfolio of other securities.  While insightful regarding risk, their work is incomplete because it does not consider the marginal contribution to return. This paper completes their analysis by including marginal contribution to return. In equilibrium the result is the capital market line and a measure similar to Jensen’s alpha that can be used to measure performance.

  8. Evasion of Neutrophil Killing by Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Will A. McGuinness

    2016-03-01

    Full Text Available Staphylococcus aureus causes many types of infections, ranging from self-resolving skin infections to severe or fatal pneumonia. Human innate immune cells, called polymorphonuclear leukocytes (PMNs or neutrophils, are essential for defense against S. aureus infections. Neutrophils are the most prominent cell type of the innate immune system and are capable of producing non-specific antimicrobial molecules that are effective at eliminating bacteria. Although significant progress has been made over the past few decades, our knowledge of S. aureus-host innate immune system interactions is incomplete. Most notably, S. aureus has the capacity to produce numerous molecules that are directed to protect the bacterium from neutrophils. Here we review in brief the role played by neutrophils in defense against S. aureus infection, and correspondingly, highlight selected S. aureus molecules that target key neutrophil functions.

  9. Population structure of Staphylococcus aureus in China

    OpenAIRE

    Yan, Xiaomei

    2015-01-01

    The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance against rifampicin doubled to 68%. Staphylococcal food poisoning (SFP) is frequent in China. Two predominant S. aureus lineages, ST6 and ST943, were identified causing outbreaks of SFP in Southern China...

  10. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    OpenAIRE

    Zhigang Li; Peres, Adam G.; Andreea C. Damian; Joaquín Madrenas

    2015-01-01

    The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and d...

  11. The sigma(54) regulon (sigmulon) of Pseudomonas putida

    DEFF Research Database (Denmark)

    Cases, I.; Ussery, David; de Lorenzo, V.

    2003-01-01

    sigma(54) is unique among the bacterial sigma factors. Besides not being related in sequence with the rest of such factors, its mechanism of transcription initiation is completely different and requires the participation of a transcription activator. In addition, whereas the rest of the alternative...... sigma factors use to be involved in transcription of somehow related biological functions, this is not the case for sigma(54) and many different and unrelated genes have been shown to be transcribed from sigma(54)-dependent promoters, ranging from flagellation, to utilization of several different carbon...... and nitrogen sources, or alginate biosynthesis. These genes have been characterized in many different bacterial species and, only until recently with the arrival of complete genome sequences, we have been able to look at the sigma(54) functional role from a genomic perspective. Aided by computational...

  12. A Review: Six Sigma Implementation Practice in Manufacturing Industries

    Directory of Open Access Journals (Sweden)

    Riddhish Thakore

    2014-11-01

    Full Text Available Higher Productivity achievement is very crucial factor for the field of production. With the High productivity various other factors must be taken in to consideration in manufacturing industries such as global competitors, diversity in product range, lead time and customer demand in terms of quality and quantity. A new benchmark called Six Sigma has been invented for dealing with all these needs. Six sigma is a quality initiative which reduces variations in a process and helps to lower the cost of product as well as process. The objective of this paper is to review and examine the advancement and encounters of six sigma practices in Global manufacturing Industries and identify the key tools for each step in successful Six Sigma project execution. The paper also integrates the lessons learned from successful six sigma projects and their prospective applications in various manufacturing Industries. In today scenario, many global manufacturing industries operate their processes at the two to four sigma quality levels.

  13. Mastite com lesões sistêmicas por Staphylococus aureus subesp. aureus em coelhos Mastitis with systemic lesions due to Staphylococus aureus subesp. aureus in rabbits

    OpenAIRE

    Sandra Davi Traverso; Leonardo da Cunha; Joaquim César Teixeira Fernandes; Alexandre Paulino Loretti; Adriana Rhoden; Elsio Wunder Jr.; David Driemeier

    2003-01-01

    Em uma criação composta por 1800 coelhos, 33% das matrizes apresentaram mastite e lesões cutâneas crostosas e purulentas. Estes animais apresentavam-se entre 10 a- 12 meses de idade e em segunda parição. Quinze coelhos afetados foram sacrificados e necropsiados. Na necropsia, além das lesões cutâneas haviam microabscessos em diversos órgãos. Das amostras coletadas isolou-se Staphylococcus aureus subesp. aureus. S. aureus subesp. aureus também foi isolado de "swab" nasal coletado do tratador e...

  14. Immunomodulation and Disease Tolerance to Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2015-11-01

    Full Text Available The Gram-positive bacterium Staphylococcus aureus is one of the most frequent pathogens that causes severe morbidity and mortality throughout the world. S. aureus can infect skin and soft tissues or become invasive leading to diseases such as pneumonia, endocarditis, sepsis or toxic shock syndrome. In contrast, S. aureus is also a common commensal microbe and is often part of the human nasal microbiome without causing any apparent disease. In this review, we explore the immunomodulation and disease tolerance mechanisms that promote commensalism to S. aureus.

  15. Methicillin-Resistant Staphylococcus aureus (MRSA) Treatment

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  16. Methicillin-Resistant Staphylococcus aureus (MRSA) Diagnosis

    Science.gov (United States)

    ... Laboratory of Bacteriology Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) Antibacterial Resistance Leadership Group (ARLG) NIAID Antimicrobial Resistance Funding Information ...

  17. Integrated design of SIGMA uranium enrichment plants

    International Nuclear Information System (INIS)

    In the present work, we describe a preliminary analysis of the design feedbacks in a Uranium Enrichment Plant, using the SIGMA concept. Starting from the result of this analysis, a computer code has been generated, which allows finding the optimal configurations of plants, for a fixed production rate. The computer code developed includes the model of the Thermohydraulic loop of a SIGMA module. The model contains numerical calculations of the main components of the circuit. During the calculations, the main components are dimensioned, for a posterior cost compute. The program also makes an estimation of the enrichment gain of the porous membrane, for each separation stage. Once the dimensions of the main components are known, using the enrichment cascade calculation, the capital and operation costs of the plant could be determined. At this point it is simple to calculate a leveled cost of the Separative Work Unit (SWU). A numerical optimizer is also included in the program. This optimizer finds the optimal cascade configuration, for a given set of design parameters. The whole-integrated program permits to investigate in detail the feedback in the component design. Therefore, the sensibility of the more relevant parameters can be computed, with respect of the economical variables of the plant. (author)

  18. Differential Poisson Sigma Models with Extended Supersymmetry

    CERN Document Server

    Arias, Cesar; Torres-Gomez, Alexander

    2016-01-01

    The induced two-dimensional topological N=1 supersymmetric sigma model on a differential Poisson manifold M presented in arXiv:1503.05625 is shown to be a special case of the induced Poisson sigma model on the bi-graded supermanifold T[0,1]M. The bi-degree comprises the standard N-valued target space degree, corresponding to the form degree on the worldsheet, and an additional Z-valued fermion number, corresponding to the degree in the differential graded algebra of forms on M. The N=1 supersymmetry stems from the compatibility between the (extended) differential Poisson bracket and the de Rham differential on M. The latter is mapped to a nilpotent vector field Q of bi-degree (0,1) on T*[1,0](T[0,1]M), and the covariant Hamiltonian action is Q-exact. New extended supersymmetries arise as inner derivatives along special bosonic Killing vectors on M that induce Killing supervector fields of bi-degree (0,-1) on T*[1,0](T[0,1]M).

  19. Ionic rotational branching ratios in resonant enhanced multiphoton ionization of NO via the A2Sigma(+)(3s sigma) and D2Sigma(+)(3p sigma) states

    Science.gov (United States)

    Rudolph, H.; Mckoy, V.; Dixit, S. N.; Huo, W. M.

    1988-01-01

    Results are presented for the rotationally resolved photoelectron spectra resulting from a (2 + 1) one-color resonant enhanced multiphoton ionization (REMPI) of NO via the rotationally clean S21(11.5) and mixed S11(15.5) + R21(15.5) branches of the 0-0 transition in the D-X band. The calculations were done in the fixed-nuclei frozen core approximation. The resulting photoionization spectra, convoluted with a Lorentzian detection function, agree qualitatively with experimental results of Viswanathan et al. (1986) and support their conclusion that the nonspherical nature of the molecular potential creates a substantial l-mixing in the continuum, which in turn leads to the intense Delta N = 0 peak. The rather strong photoelectron energy dependence of the rotational branching ratios of the D 2Sigma(+) S21(11.5) line was investigated and compared to the weak energy dependence of the A 2Sigma(+) R22(21.5) line.

  20. Six Sigma process improvements in automotive parts production

    OpenAIRE

    Soković, M.; D. Pavletić; E. Krulčić

    2006-01-01

    Purpose: of this paper: In the paper is presented a Six Sigma project, undertaken within company for production automotive parts, which deals with identification and reduction of production cost in the deburring process for gravity die-castings and improvement of quality level of produced parts.Design/methodology/approach: The objectives are achieved by application of Six Sigma approach to quality improvement project in automotive industry. The applied Six Sigma approach includes team works t...

  1. Implications of sigma models in the standard model and beyond

    International Nuclear Information System (INIS)

    After a brief introduction to the sigma model in QCD, we discuss how the sigma model can be relevant in the Standard Model. It is shown to be useful in the analysis of weak processes, such as the study of ΔI=1/2 rule, and in the analysis of the Higgs sector as well. The sigma model description is also shown to be quite useful in searching for the effects of New Physics via gauge boson self-interactions. (author)

  2. Gauged linear sigma model for exotic five-brane

    International Nuclear Information System (INIS)

    We study an N=(4,4) supersymmetric gauged linear sigma model which gives rise to the nonlinear sigma model for multi-centered KK-monopoles. We find a new T-duality transformation of the model even in the presence of F-terms. Performing T-duality, we find the gauged linear sigma model whose IR limit describes the exotic 522-brane with B-field

  3. Quality and Competitiveness: A Lean Six Sigma Approach

    OpenAIRE

    Irina-Virginia Drăgulănescu; Delia Popescu

    2015-01-01

    Originally developed to improve the quality and production efficiency, Lean Six Sigma is now widely adopted in other non-manufacturing sectors such as financial, trade, services, etc. The methodology known as Lean Six Sigma combines the Six Sigma techniques, ‒ which allow companies to reduce manufacturing defects ‒ and the Lean Manufacturing principles, ‒ which help companies benefit from faster processing for lower costs and with superior quality. As a result of the research, the authors obs...

  4. Updating the $\\sigma$-$T$ relationship for galaxy clusters

    OpenAIRE

    Wu, Xiang-Ping; Fang, Li-Zhi; Xu, Wen

    1998-01-01

    The relationship between the X-ray determined temperature $T$ of the intracluster gas and the optical measured velocity dispersion $\\sigma$ of the cluster galaxies is often believed to be not only a straightforward but also robust test for the dynamical properties of galaxy clusters. Here, we present the $\\sigma$-$T$ relationship using the 94 clusters drawn from the largest sample of 149 clusters in literature, for which both $\\sigma$ and $T$ are observationally determined. Employment of the ...

  5. Six Sigma, absorptive capacity and organizational learning orientation

    OpenAIRE

    Guti??rrez-Guti??rrez, Leopoldo; Bustinza S??nchez, ??scar Fernando; Barrales-Molina, Vanesa

    2011-01-01

    Abstract The importance of the Six Sigma methodology in industry is growing constantly. However, there are few empirical studies that analyze the advantages of this methodology and its positive effects on organizational performance. The purpose of this paper is to extend understanding of the success of Six Sigma quality management initiatives by investigating the effects of Six Sigma teamwork and process management on absorptive capacity. It also seeks to understand the relation be...

  6. Genome-wide analysis of the general stress response network in Escherichia coli: {sigma}S-dependent genes, promoters and sigma factor selectivity

    OpenAIRE

    Weber, T. A.; T. POLEN; Heuveling, J.; Wendisch, V. F.; HENGGE R

    2005-01-01

    The sigmaS (or RpoS) subunit of RNA polymerase is the master regulator of the general stress response in Escherichia coli. While nearly absent in rapidly growing cells, sigmaS is strongly induced during entry into stationary phase and/or many other stress conditions and is essential for the expression of multiple stress resistances. Genome-wide expression profiling data presented here indicate that up to 10% of the E. coli genes are under direct or indirect control of sigmaS and that sigmaS s...

  7. Decline in ribosomal fidelity contributes to the accumulation and stabilization of the master stress response regulator sigmaS upon carbon starvation.

    Science.gov (United States)

    Fredriksson, Asa; Ballesteros, Manuel; Peterson, Celeste N; Persson, Orjan; Silhavy, Thomas J; Nyström, Thomas

    2007-04-01

    The sigma(S) subunit of RNA polymerase is a master regulator of Escherichia coli that retards cellular senescence and bestows cells with general stress protective functions during growth arrest. We show that mutations and drugs triggering translational errors elevate sigma(S) levels and stability. Furthermore, mutations enhancing translational fidelity attenuate induction of the rpoS regulon and prevent stabilization of sigma(S) upon carbon starvation. Destabilization of sigma(S) by increased proofreading requires the presence of the sigma(S) recognition factor SprE (RssB) and the ClpXP protease. The data further suggest that sigma(S) becomes stabilized upon starvation as a result of ClpP sequestration and this sequestration is enhanced by oxidative modifications of aberrant proteins produced by erroneous translation. ClpP overproduction counteracted starvation-induced stabilization of sigma(S), whereas overproduction of a ClpXP substrate (ssrA-tagged GFP) stabilized sigma(S) in exponentially growing cells. We present a model for the sequence of events leading to the accumulation and activation of sigma(S) upon carbon starvation, which are linked to alterations in both ribosomal fidelity and efficiency. PMID:17403784

  8. Mucosal vaccination by adenoviruses displaying reovirus sigma 1

    Energy Technology Data Exchange (ETDEWEB)

    Weaver, Eric A. [Department of Internal Medicine, Division of Infectious Diseases, Translational Immunovirology and Biodefense Program, Mayo Clinic, Rochester, MN 55902 (United States); Camacho, Zenaido T. [Department of Cell Biology, Department of Natural Sciences, Western New Mexico University, Silver City, NM 88062 (United States); Hillestad, Matthew L. [Nephrology Training Program, Mayo Clinic, Rochester, MN 55902 (United States); Crosby, Catherine M.; Turner, Mallory A.; Guenzel, Adam J.; Fadel, Hind J. [Virology and Gene Therapy Graduate Program, Mayo Clinic, Rochester, MN 55902 (United States); Mercier, George T. [Department of Physics, University of Houston, Houston, TX 77004 (United States); Barry, Michael A., E-mail: mab@mayo.edu [Department of Internal Medicine, Division of Infectious Diseases, Translational Immunovirology and Biodefense Program, Mayo Clinic, Rochester, MN 55902 (United States); Department of Immunology and Department of Molecular Medicine, Mayo Clinic, Rochester, MN 55902 (United States)

    2015-08-15

    We developed adenovirus serotype 5 (Ad5) vectors displaying the sigma 1 protein from reovirus as mucosal vaccines. Ad5-sigma retargets to JAM-1 and sialic acid, but has 40-fold reduced gene delivery when compared to Ad5. While weaker at transduction, Ad5-sigma generates stronger T cell responses than Ad5 when used for mucosal immunization. In this work, new Ad5-fiber-sigma vectors were generated by varying the number of fiber β-spiral shaft repeats (R) between the fiber tail and sigma. Increasing chimera length led to decreasing insertion of these proteinsAd5 virions. Ad-R3 and R14 vectors effectively targeted JAM-1 in vitro while R20 did not. When wereused to immunize mice by the intranasal route, Ad5-R3-sigma produced higher serum and vaginal antibody responses than Ad5. These data suggest optimized Ad-sigma vectors may be useful vectors for mucosal vaccination. - Highlights: • Constructed adenoviruses (Ads) displaying different reovirus sigma 1 fusion proteins. • Progressively longer chimeras were more poorly encapsidated onto Ad virions. • Ad5-R3-sigma mediated better systemic and mucosal immune responses than Ad5.

  9. Mucosal vaccination by adenoviruses displaying reovirus sigma 1

    International Nuclear Information System (INIS)

    We developed adenovirus serotype 5 (Ad5) vectors displaying the sigma 1 protein from reovirus as mucosal vaccines. Ad5-sigma retargets to JAM-1 and sialic acid, but has 40-fold reduced gene delivery when compared to Ad5. While weaker at transduction, Ad5-sigma generates stronger T cell responses than Ad5 when used for mucosal immunization. In this work, new Ad5-fiber-sigma vectors were generated by varying the number of fiber β-spiral shaft repeats (R) between the fiber tail and sigma. Increasing chimera length led to decreasing insertion of these proteinsAd5 virions. Ad-R3 and R14 vectors effectively targeted JAM-1 in vitro while R20 did not. When wereused to immunize mice by the intranasal route, Ad5-R3-sigma produced higher serum and vaginal antibody responses than Ad5. These data suggest optimized Ad-sigma vectors may be useful vectors for mucosal vaccination. - Highlights: • Constructed adenoviruses (Ads) displaying different reovirus sigma 1 fusion proteins. • Progressively longer chimeras were more poorly encapsidated onto Ad virions. • Ad5-R3-sigma mediated better systemic and mucosal immune responses than Ad5

  10. Summary talk at the conference on the $\\sigma$ resonance

    CERN Document Server

    Törnqvist, N A

    2000-01-01

    This report summarizes the most important results presented at the recent conference held at the Yukawa Institute of Theoretical Physics in Kyoto, devoted to the recently confirmed light sigma resonance. Remarkably, all speakers at this meeting took the light sigma for granted and many mass and width estimations near 500 MeV were presented. We emphasize that if the light and broad sigma is accepted as a true resonance it explains many basic problems of low energy hadronic physics in a simple way, especially if the linear sigma model is used as an approximate effective low energy theory.

  11. Staphylococcus aureus small colony variants in diabetic foot infections

    OpenAIRE

    Cervante-García, Estrella; García-Gonzalez, Rafael; Reyes-Torres, Angélica; Resendiz-Albor, Aldo Arturo; Salazar-Schettino, Paz María

    2015-01-01

    Background: Staphylococcus aureus (S. aureus) is one of the major pathogens causing chronic infections. The ability of S. aureus to acquire resistance to a diverse range of antimicrobial compounds results in limited treatment options, particularly in methicillin-resistant S. aureus (MRSA). A mechanism by which S. aureus develops reduced susceptibility to antimicrobials is through the formation of small colony variants (SCVs). Infections by SCVs of S. aureus are an upcoming problem due to diff...

  12. Evaluation of Two New Chromogenic Media, CHROMagar MRSA and S. aureus ID, for Identifying Staphylococcus aureus and Screening Methicillin-Resistant S. aureus

    OpenAIRE

    Hedin, Göran; Fang, Hong

    2005-01-01

    Thirty-nine methicillin-resistant Staphylococcus aureus (MRSA) isolates with diverse genetic backgrounds and two reference strains were correctly identified as S. aureus on CHROMagar MRSA and S. aureus ID media. Growth inhibition on CHROMagar MRSA was noted. A combination of cefoxitin disk and S. aureus ID was found suitable for rapid MRSA screening.

  13. Identification of conserved amino acid residues of the Salmonella sigmaS chaperone Crl involved in Crl-sigmaS interactions.

    Science.gov (United States)

    Monteil, Véronique; Kolb, Annie; D'Alayer, Jacques; Beguin, Pierre; Norel, Françoise

    2010-02-01

    Proteins that bind sigma factors typically attenuate the function of the sigma factor by restricting its access to the RNA polymerase (RNAP) core enzyme. An exception to this general rule is the Crl protein that binds the stationary-phase sigma factor sigma(S) (RpoS) and enhances its affinity for the RNAP core enzyme, thereby increasing expression of sigma(S)-dependent genes. Analyses of sequenced bacterial genomes revealed that crl is less widespread and less conserved at the sequence level than rpoS. Seventeen residues are conserved in all members of the Crl family. Site-directed mutagenesis of the crl gene from Salmonella enterica serovar Typhimurium and complementation of a Deltacrl mutant of Salmonella indicated that substitution of the conserved residues Y22, F53, W56, and W82 decreased Crl activity. This conclusion was further confirmed by promoter binding and abortive transcription assays. We also used a bacterial two-hybrid system (BACTH) to show that the four substitutions in Crl abolish Crl-sigma(S) interaction and that residues 1 to 71 in sigma(S) are dispensable for Crl binding. In Escherichia coli, it has been reported that Crl also interacts with the ferric uptake regulator Fur and that Fur represses crl transcription. However, the Salmonella Crl and Fur proteins did not interact in the BACTH system. In addition, a fur mutation did not have any significant effect on the expression level of Crl in Salmonella. These results suggest that the relationship between Crl and Fur is different in Salmonella and E. coli. PMID:20008066

  14. [In vitro activities of quinupristin/dalfopristin in combination with vancomycin and gatifloxacin against Staphylococcus aureus and Enterococcus faecium clinical isolates].

    Science.gov (United States)

    Gülden, Erdinç; Ermertcan, Safak

    2009-01-01

    In this study, it was aimed to investigate the effects of quinupristin/dalfopristin in combination with vancomycin and gatifloxacin against Staphylococcus aureus and Enterococcus faecium isolates. A total 17 gram-positive bacterial isolates, composed of 4 methicillin-susceptible S. aureus (MSSA), 5 methicillin-resistant S. aureus (MRSA), 3 vancomycin-susceptible E. faecium (VSEF) and 5 vancomycin-resistant E. faecium (VREF) isolates, recovered from several clinical specimens in Ege University Faculty of Medicine, Turkey, were enrolled in this study. Antibiotic susceptibilities and interactions between antibiotics were determined by E-test (AB Biodisk, Sweden) method and fractional inhibitory concentration (FIC) indices were calculated for each combination. Synergistic activity was detected in only one MSSA isolate with the combination of quinupristin/dalfopristin and vancomycin (sigma FIC= 0.5). While the combination of quinupristin/dalfopristin and gatifloxacin yielded synergistic interaction in two MRSA and one MSSA isolate (sigma FIC= 0.37, 0.36 and 0.28, respectively) and additive interaction in one MSSA isolate (sigma FIC= 0.75), synergic activity was detected in one of the VREF isolate (sigma FIC= 0.29) and additive activity in two isolates (sigma FIC= 0.75 and 0.91, respectively). In this study, it was observed that the combination of quinupristin/dalfopristin and gatifloxacin was superior to the combination of quinupristin/dalfopristin and vancomycin especially in MRSA and VREF isolates. These in vitro results should be supported by in vivo studies which will guide the use of antibiotic combinations especially in the treatment of multi-resistant gram-positive bacterial infections. PMID:19334380

  15. Characterization of pulmonary sigma receptors by radioligand binding.

    Science.gov (United States)

    Lever, John R; Litton, Tyler P; Fergason-Cantrell, Emily A

    2015-09-01

    This study establishes the expression of appreciable populations of sites on mouse lung membranes that exhibit radioligand binding properties and pharmacology consistent with assignment as sigma1 and sigma2 receptors. Specific binding of the sigma1 receptor radioligand [(3)H](+)-pentazocine reached steady state within 6h at 37°C. Saturation studies revealed high affinity binding to a single class of sites (Kd 1.36±0.04nM; Bmax 967±11fmol/mg protein). Inhibition studies showed appropriate sigma1 receptor pharmacology, including higher affinity for (+)-N-allylnormetazocine with respect to the (-)-enantiomer, and positive allosteric modulation of dextromethorphan binding by phenytoin. Using [(3)H]1,3-di(2-tolyl)guanidine in the presence of (+)-pentazocine to assess sigma2 receptor binding, steady state was achieved within 2min at 25°C. Cold saturation studies revealed one high affinity, low capacity binding site (Kd 31.8±8.3nM; Bmax 921±228fmol/mg protein) that displayed sigma2 receptor pharmacology. A very low affinity, high capacity interaction also was observed that represents saturable, but not sigma receptor specific, binding. A panel of ligands showed rank order inhibition of radioligand binding appropriate for the sigma2 receptor, with ifenprodil displaying the highest apparent affinity. In vivo, dextromethorphan inhibited the specific binding of a radioiodinated sigma1 receptor ligand in lung with an ED50 of 1.2μmol/kg, a value near the recommended dosage for the drug as a cough suppressant. Overall, the present work provides a foundation for studies of drug interactions with pulmonary sigma1 and sigma2 receptors in vitro and in vivo. PMID:26004528

  16. The -35 sequence location and the Fis-sigma factor interface determine sigmas selectivity of the proP (P2) promoter in Escherichia coli.

    Science.gov (United States)

    Typas, Athanasios; Stella, Stefano; Johnson, Reid C; Hengge, Regine

    2007-02-01

    The P2 promoter of proP, encoding a transporter for proline and glycine betaine in Escherichia coli, is a unique paradigm, where master regulators of different growth stages, Fis and sigma(S) (RpoS), collaborate to achieve promoter activation. It is also the only case described where Fis functions as class II transcriptional activator (centred at -41). Here we show that the degenerate -35 sequence, and the location of the Fis binding site, which forces a suboptimal 16 bp spacing between the -35 and -10 elements, allow only sigma(S) but not sigma(70) to function at proP (P2). Moreover, the interface between Fis and sigma(S) seems better suited to sigma(S), due to a single residue difference between sigma(S) and sigma(70). Nevertheless, Fis can activate RNA polymerase containing sigma(70) at a proP (P2) promoter variant, in which a typical sigma(70)-35 recognition sequence has been introduced at a 17 bp distance from the -10 hexamer. In summary, we elucidate the rules that govern sigma factor selectivity in the presence of a class II activator, provide new insight into transcriptional activation by Fis from this position, and clarify, why the proP (P2) promoter is precisely activated during a short time window of the growth cycle, when Fis and sigma(S) are both present. PMID:17302803

  17. The cell surface proteome of Staphylococcus aureus

    NARCIS (Netherlands)

    Dreisbach, Annette; van Dijl, Jan Maarten; Buist, Girbe

    2011-01-01

    The Gram-positive bacterium Staphylococcus aureus is a wide spread opportunistic pathogen that can cause a range of life-threatening diseases. To obtain a better understanding of the global mechanisms for pathogenesis and to identify novel targets for therapeutic interventions, the S. aureus proteom

  18. Population structure of Staphylococcus aureus in China

    NARCIS (Netherlands)

    Yan, Xiaomei

    2015-01-01

    The present PhD research was aimed at analysing the population structure of Staphylococcus aureus in China. Between 2000 and 2005 we found that patients from a single Chinese hospital showed increasing trends in antimicrobial resistance. Among methicillin-resistant S. aureus (MRSA), resistance again

  19. Linear Sigma Models for Open Strings

    International Nuclear Information System (INIS)

    We formulate and study a class of massive N = 2 supersymmetric gauge field theories coupled to boundary degrees of freedom on the strip. For some values of the parameters, the infrared limits of these theories can be interpreted as open string sigma models describing D-branes in large-radius Calabi-Yau compactifications. For other values of the parameters, these theories flow to CFTs describing branes in more exotic, non-geometric phases of the Calabi-Yau moduli space such as the Landau-Ginzburg orbifold phase. Some simple properties of the branes (like large radius monodromies and spectra of worldvolume excitations) can be computed in our model. We also provide simple worldsheet models of the transitions which occur at loci of marginal stability, and of Higgs-Coulomb transitions

  20. Linear sigma models for open strings

    International Nuclear Information System (INIS)

    We formulate and study a class of massive N=2 supersymmetric gauge field theories coupled to boundary degrees of freedom on the strip. For some values of the parameters, the infrared limits of these theories can be interpreted as open string sigma models describing D-branes in large-radius Calabi-Yau compactifications. For other values of the parameters, these theories flow to CFTs describing branes in more exotic, non-geometric phases of the Calabi-Yau moduli space such as the Landau-Ginzburg orbifold phase. Some simple properties of the branes (like large radius monodromies and spectra of worldvolume excitations) can be computed in our model. We also provide simple worldsheet models of the transitions which occur at loci of marginal stability, and of Higgs-Coulomb transitions. (author)

  1. Polarimetric observations of $\\sigma$ Orionis E

    CERN Document Server

    Carciofi, Alex C; Townsend, Richard H D; Bjorkman, Jon E

    2013-01-01

    Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These \\textit{magnetospheres} have been studied spectroscopically, photometrically and, more recently, interferometrically. Here we report on the first firm detection of a magnetosphere in continuum linear polarization, as a result of monitoring of $\\sigma$\\,Ori\\,E at the Pico dos Dias Observatory. {The non-zero intrinsic polarization indicates an asymmetric structure, whose minor elongation axis is oriented $150\\fdg0$ east of the celestial north.} A modulation of the polarization was observed, with a period of half of the rotation period, which supports the theoretical prediction of the presence of two diametrally opposed, co-rotating blobs of gas. A phase lag of -0.085 was detected between the polarization minimum and the primary minimum of the light curve, suggestive of a complex shape of the plasma clouds. We present a preliminary analysis of the data with the Rigidly Rotating Magnetosphere model, which...

  2. QCD monopole and sigma meson coupling

    CERN Document Server

    Iwazaki, Aiichi

    2016-01-01

    Under the assumption of the Abelian dominance in QCD, we show that chiral condensate is locally present around a QCD monopole. The appearance of the chiral condensate around a GUT monopole was shown in the previous analysis of the Rubakov effect. We apply a similar analysis to the QCD monopole. It follows that the condensation of the monopole carrying the chiral condensate leads to the chiral symmetry breaking as well as quark confinement. To realize the result explicitly, we present a phenomenological linear sigma model coupled with the monopoles, in which the monopole condensation causes the chiral symmetry breaking as well as confinement. The monopoles are assumed to be described by a model of dual superconductor. We identify the monopoles with scalar isoscalar $f_0$ mesons with masses $1400\\sim 1700$ MeV as well as dual gauge fields with $h_1$ vector mesons with masses $\\sim 1500$MeV.

  3. Anglophonia-SIGMA N°28. English Linguistics

    Directory of Open Access Journals (Sweden)

    Manuel JOBERT

    2012-03-01

    Full Text Available Le numéro 28 / 2010 de la revue Anglophonia- SIGMA, coordonné par Nathalie Vincent-Arnaud et Wilfrid Rotgé, réunit les huit articles retenus par le comité de rédaction et de lecture de la revue. Anglophonia fait preuve d’un esprit d’ouverture reconnu et aucune approche (théorique ou méthodologique n’est privilégiée. Le présent numéro ne fait pas exception et regroupe des articles qui trouvent naturellement leur place sous la rubrique « grammaire linguistique » ainsi que des articles relevant...

  4. Boundary spectra in superspace {sigma}-models

    Energy Technology Data Exchange (ETDEWEB)

    Quella, T. [Amsterdam Univ. (Netherlands). Inst. voor Theoretische Fysica]|[Isaac Newton Inst. for Mathematical Sciences, Cambridge (United Kingdom); Schomerus, V. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[Isaac Newton Inst. for Mathematical Sciences, Cambridge (United Kingdom); Creutzig, T. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2007-12-15

    In this note we compute exact boundary spectra for D-instantons in {sigma}-models on the supergroup PSL(22). Our results are obtained through an explicit summation of the perturbative expansion for conformal dimensions to all orders in the curvature radius. The analysis exploits several remarkable properties of the perturbation series that arises from rescalings of the metric on PSL(22) relative to a fixed Wess- Zumino term. According to Berkovits, Vafa and Witten, the models are relevant in the context of string theory on AdS{sub 3} with non-vanishing RR-flux. The note concludes with a number of comments on various possible generalizations to other supergroups and higher dimensional supercoset theories. (orig.)

  5. Dirichlet sigma models and mean curvature flow

    CERN Document Server

    Bakas, I

    2007-01-01

    The mean curvature flow describes the parabolic deformation of embedded branes in Riemannian geometry driven by their extrinsic mean curvature vector, which is typically associated to surface tension forces. It is the gradient flow of the area functional, and, as such, it is naturally identified with the boundary renormalization group equation of Dirichlet sigma models away from conformality, to lowest order in perturbation theory. D-branes appear as fixed points of this flow having conformally invariant boundary conditions. Simple running solutions include the paper-clip and the hair-pin (or grim-reaper) models on the plane, as well as scaling solutions associated to rational (p, q) closed curves and the decay of two intersecting lines. Stability analysis is performed in several cases while searching for transitions among different brane configurations. The combination of Ricci with the mean curvature flow is examined in detail together with several explicit examples of deforming curves on curved backgrounds...

  6. Sigma A recognition sites in the Bacillus subtilis genome

    DEFF Research Database (Denmark)

    Jarmer, Hanne Østergaard; Larsen, Thomas Schou; Krogh, Anders Stærmose;

    2001-01-01

    A hidden Markov model of sigma (A) RNA polymerase cofactor recognition sites in Bacillus subtilis, containing either the common or the extended -10 motifs, has been constructed based on experimentally verified sigma (A) recognition sites. This work suggests that more information exists at the ini...

  7. Application of Six Sigma Method to EMS Design

    Science.gov (United States)

    Rusko, Miroslav; Králiková, Ružena

    2011-01-01

    The Six Sigma method is a complex and flexible system of achieving, maintaining and maximizing the business success. Six Sigma is based mainly on understanding the customer needs and expectation, disciplined use of facts and statistics analysis, and responsible approach to managing, improving and establishing new business, manufacturing and service processes.

  8. A Geographical Information System for Malaria in Colombia (SIGMA)

    International Nuclear Information System (INIS)

    A Geographical Information System for Malaria in Colombia (SIGMA) is introduced and its capabilities and modules are described. It allows the interactive visualization of the Colombian Ministry of Social Protection database at national, regional and municipal levels and the analysis of relationships with different environmental and climatic variables. SIGMA is a powerful decision support system for human health intervention and management programs in Colombia

  9. Conversations with Early Leaders of Eta Sigma Gamma

    Science.gov (United States)

    Clark, Jeffrey K.; Seabert, Denise M.; Goldsmith, Mal

    2007-01-01

    Anniversaries are often a time to reflect on the past. With that in mind, interviews were conducted with early key leaders of Eta Sigma Gamma to explore their perspectives of the organization's growth and development as well as their hopes for the future of ESG. The individuals interviewed included the surviving founders of Eta Sigma Gamma, the…

  10. Studi Implementasi Six Sigma dalam Sistem Inventori Galangan Kapal

    Directory of Open Access Journals (Sweden)

    Elwin Elwin

    2012-09-01

    Full Text Available Dalam industri galangan kapal terdapat bahan baku, barang dalam proses dan barang jadi yang merupakan macam-macam bentuk dari persediaan dan berhubungan dengan stok, ketika persediaan tidak dikelola dengan benar maka akan terjadi pembengkakkan biaya/pengeluaran biaya yang tidak dibutuhkan. Tugas akhir ini bertujuan untuk mengetahui kondisi inventori di PT. Dok dan Perkapalan Surbaya, untuk mengetahui faktor-faktor yang menjadi penyebab terjadinya variabilitas output six sigma dan mengurangi defect pada sistem inventori dengan menggunakan metode six sigma DMAIC (Define, Measure, Analyze, Improve dan Control,. Berdasarkan perhitungan Material Pipa mengalami defect sebesar 50.98% dengan nilai sigma 1.48, Material Elbow mengalami defect sebesar 89.80% dengan nilai sigma 0.33, Material Flange mengalami defect sebesar 71.99% dengan nilai sigma 0.90, Material Paking mengalami defect sebesar 13.12% dengan nilai sigma 2.74 dan Material Mur mengalami defect sebesar 17.26% dengan nilai sigma 2.57. Sesuai dengan perhitungan reorder point for the inventory untuk masing-masing material, maka dapat diketahui bahwa material Pipa reoder point adalah 58 lonjor, elbow 100 buah, flange 168 buah, paking 24 buah dan mur 946 buah. Nilai sigma yang diperoleh dalam perhitungan tingkat persediaan masih jauh dari nilai yang seharusnya dapat dicapai oleh suatu perusahaan (6σ, sehingga dilakukan tahap Improve dengan metode Failure Mode and Effect Analysis (FMEA, pembuat SOP Pengendalian persediaan material dengan format baru serta galangan perlu melakukan perhitungan reorder point.  

  11. The sigma(54) regulon (sigmulon) of Pseudomonas putida

    DEFF Research Database (Denmark)

    Cases, I.; Ussery, David; de Lorenzo, V.

    2003-01-01

    methods, the sigma(54) regulon has been studied both in Escherichia coli, Salmonella typhimurium and several species of the Rhizobiaceae. Here we present the analysis of the sigma(54) regulon (sigmulon) in the complete genome of Pseudomonas putida KT2440. We have developed an improved method for the...

  12. Sigma A recognition sites in the Bacillus subtilis genome

    DEFF Research Database (Denmark)

    Jarmer, Hanne Østergaard; Larsen, Thomas Schou; Krogh, Anders Stærmose; Saxild, Hans Henrik; Brunak, Søren; Knudsen, Steen

    2001-01-01

    A hidden Markov model of sigma (A) RNA polymerase cofactor recognition sites in Bacillus subtilis, containing either the common or the extended -10 motifs, has been constructed based on experimentally verified sigma (A) recognition sites. This work suggests that more information exists at the...

  13. Environmental Data Flow Six Sigma Process Improvement Savings Overview

    Energy Technology Data Exchange (ETDEWEB)

    Paige, Karen S [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-05-20

    An overview of the Environmental Data Flow Six Sigma improvement project covers LANL’s environmental data processing following receipt from the analytical laboratories. The Six Sigma project identified thirty-three process improvements, many of which focused on cutting costs or reducing the time it took to deliver data to clients.

  14. Wess Zumino Couplings for Generalized $\\Sigma$ Orbifold Fixed-points

    CERN Document Server

    Ospina-Giraldo, J F

    2000-01-01

    The Wess-Zumino couplings for generalized sigma-orbifold fixed-points are presented and the generalized GS 6-form that encoding the complete sigma-standard gauge-gravitational-non standard gauge anomaly and its opposite inflow is derived.

  15. The LHCb pentaquark as a $\\bar{D}^*\\Sigma_c-\\bar{D}^*\\Sigma_c^*$ molecular state

    CERN Document Server

    Roca, L; Oset, E

    2015-01-01

    We perform a theoretical analysis of the $\\Lambda_b \\to J/\\psi K^- p$ reaction from where a recent LHCb experiment extracts a $\\Lambda(1405)$ contribution in the $K^- p$ spectrum close to threshold and two baryon states of hidden charm in the $J/\\psi\\,p$ spectrum. We recall that baryon states of this type have been theoretically predicted matching the mass, width and $J^P$ of the experiment, concretely some states built up from the $J/\\psi\\, N$, $\\bar D^* \\Lambda_c$, $\\bar D^* \\Sigma_c$, $\\bar D \\Sigma^*_c$ and $\\bar D^* \\Sigma^*_c$ coupled channels. We assume that the observed narrow state around 4450 MeV has this nature and we are able to describe simultaneously the shapes and relative strength of the the $K^- p$ mass distribution close to threshold and the peak of the $J/\\psi\\,p$ distribution, with values of the $J/\\psi\\, p$ coupling to the resonance in line with the theoretical ones. The non trivial matching of many properties gives support to a $J^P=3/2^-$ assignment to this state and to its nature as a ...

  16. Lean six sigma case studies in the healthcare enterprise

    CERN Document Server

    Furterer, Sandra L

    2014-01-01

    This book provides a detailed description of how to apply Lean Six Sigma in the health care industry, with a special emphasis on process improvement and operations management in hospitals.  The book begins with a description of the Enterprise Performance Excellence (EPE) improvement methodology developed by the author that links several methodologies including systems thinking, theory of constraints, Lean and Six Sigma to provide an enterprise-wide prioritization and value-chain view of health care. The EPE methodology helps to improve flow at the macro or value-chain level, and then identifies Lean Six Sigma detailed improvements that can further improve processes within the value-chain.  The book also provides real-world health care applications of the EPE and Lean Six Sigma methodologies that showed significant results on throughput, capacity, operational and financial performance. The Enterprise Performance Excellence methodology is described, and also the Six Sigma DMAIC (Define-Measure-Analyze-Improve...

  17. Dyson-Maleev representation of nonlinear sigma models

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, D A [Institute for Theoretical Physics, Ecole Polytechnique Federale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Skvortsov, M A [Landau Institute for Theoretical Physics, Chernogolovka, 142432 Moscow (Russian Federation)

    2008-05-30

    For nonlinear sigma models in the unitary symmetry class, the nonlinear target space can be parameterized with cubic polynomials. This choice of coordinates has been known previously as the Dyson-Maleev parameterization for spin systems, and we show that it can be applied to a wide range of sigma models. The practical use of this parameterization includes simplification of diagrammatic calculations (in perturbative methods) and of algebraic manipulations (in non-perturbative approaches). We illustrate the use and specific issues of the Dyson-Maleev parameterization with three examples: the Keldysh sigma model for time-dependent random Hamiltonians, the supersymmetric sigma model for random matrices and the supersymmetric transfer-matrix technique for quasi-one-dimensional disordered wires. We demonstrate that nonlinear sigma models of unitary-like symmetry classes C and B/D also admit the Dyson-Maleev parameterization.

  18. The linear U3 x U3 sigma Model, the sigma resonance and the spontaneous breaking of symmetries

    CERN Document Server

    Törnqvist, N A

    1998-01-01

    My recent fit of the light scalar mesons is discussed in the light of the U3 x U3 linear sigma model. The argument for why there exists a light and broad sigma meson is explained in more detail, and the mechanism of spontaneous symmetry breaking is discussed.

  19. Erratum to "Nuclear Effects on R=\\sigma_L\\/\\sigma_T in Deep-Inelastic Scattering", In

    CERN Document Server

    Airapetian, A

    2002-01-01

    This erratum revokes the main conclusion of a Letter that reported measurements of cross sections for deep-inelastic scattering (DIS) of leptons on $^3$He and $^{14}$N targets, expressed as ratios of $\\sigma_A / \\sigma_D$ to the cross section on the deuterium target.

  20. Prospects for observing the lowest-lying odd-parity $\\Sigma_c$ and $\\Sigma_b$ baryons

    CERN Document Server

    Karliner, Marek

    2015-01-01

    There exist candidates for the negative-parity states $\\Lambda_{c,b}(1/2^-, 3/2^-)$ consisting of an isospin-zero, spin-zero light diquark $[ud]$ with one unit of orbital angular momentum with respect to a $c,b$ quark. However, there exists only one candidate for the orbital excitations of the $\\Sigma_c(1/2^+)$ and $\\Sigma_c^*(3/2^+)$, and none for the orbital excitations of $\\Sigma_b(1/2^+)$ or $\\Sigma_b^*(3/2^+)$. We extend a previous discussion of odd-parity $\\Lambda_{c,b}$ states and explore some patterns of the odd-parity $\\Sigma_{c,b}$ baryons consisting of a light isospin-one nonstrange diquark $(uu,ud,dd)$ in a state of $L=1$ with respect to the spin-1/2 heavy quark $(c,b)$.

  1. Reduced capacity of alternative sigmas to melt promoters ensures stringent promoter recognition.

    Science.gov (United States)

    Koo, Byoung-Mo; Rhodius, Virgil A; Nonaka, Gen; deHaseth, Pieter L; Gross, Carol A

    2009-10-15

    In bacteria, multiple sigmas direct RNA polymerase to distinct sets of promoters. Housekeeping sigmas direct transcription from thousands of promoters, whereas most alternative sigmas are more selective, recognizing more highly conserved promoter motifs. For sigma(32) and sigma(28), two Escherichia coli Group 3 sigmas, altering a few residues in Region 2.3, the portion of sigma implicated in promoter melting, to those universally conserved in housekeeping sigmas relaxed their stringent promoter requirements and significantly enhanced melting of suboptimal promoters. All Group 3 sigmas and the more divergent Group 4 sigmas have nonconserved amino acids at these positions and rarely transcribe >100 promoters. We suggest that the balance of "melting" and "recognition" functions of sigmas is critical to setting the stringency of promoter recognition. Divergent sigmas may generally use a nonoptimal Region 2.3 to increase promoter stringency, enabling them to mount a focused response to altered conditions. PMID:19833768

  2. Genomic Analysis of Companion Rabbit Staphylococcus aureus

    Science.gov (United States)

    Holmes, Mark A.; Harrison, Ewan M.; Fisher, Elizabeth A.; Graham, Elizabeth M.; Parkhill, Julian; Foster, Geoffrey; Paterson, Gavin K.

    2016-01-01

    In addition to being an important human pathogen, Staphylococcus aureus is able to cause a variety of infections in numerous other host species. While the S. aureus strains causing infection in several of these hosts have been well characterised, this is not the case for companion rabbits (Oryctolagus cuniculus), where little data are available on S. aureus strains from this host. To address this deficiency we have performed antimicrobial susceptibility testing and genome sequencing on a collection of S. aureus isolates from companion rabbits. The findings show a diverse S. aureus population is able to cause infection in this host, and while antimicrobial resistance was uncommon, the isolates possess a range of known and putative virulence factors consistent with a diverse clinical presentation in companion rabbits including severe abscesses. We additionally show that companion rabbit isolates carry polymorphisms within dltB as described as underlying host-adaption of S. aureus to farmed rabbits. The availability of S. aureus genome sequences from companion rabbits provides an important aid to understanding the pathogenesis of disease in this host and in the clinical management and surveillance of these infections. PMID:26963381

  3. [Staphylococcus aureus and antibiotic resistance].

    Science.gov (United States)

    Sancak, Banu

    2011-07-01

    After the report of first case of methicillin-resistant Staphylococcus aureus (MRSA) in 1961, MRSA become a major problem worldwide. Over the last decade MRSA strains have emerged as serious pathogens in nosocomial and community settings. Glycopeptides (vancomycin and teicoplanin) are still the current mainstay of therapy for infections caused by MRSA. In the last decade dramatic changes have occurred in the epidemiology of MRSA infections. The isolates with reduced susceptibility and in vitro resistance to vancomycin have emerged. Recently, therapeutic alternatives such as quinupristin/dalfopristin, linezolid, tigecycline and daptomycin have been introduced into clinical practice for treating MRSA infections. Nevertheless, these drugs are only approved for certain indication and resistance has already been reported. In this review, the new information on novel drugs for treating MRSA infections and the resistance mechanisms of these drugs were discussed. PMID:21935792

  4. Exfoliative Toxins of Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Michal Bukowski

    2010-05-01

    Full Text Available Staphylococcus aureus is an important pathogen of humans and livestock. It causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. Among multiple virulence factors, staphylococci secrete several exotoxins directly associated with particular disease symptoms. These include toxic shock syndrome toxin 1 (TSST-1, enterotoxins, and exfoliative toxins (ETs. The latter are particularly interesting as the sole agents responsible for staphylococcal scalded skin syndrome (SSSS, a disease predominantly affecting infants and characterized by the loss of superficial skin layers, dehydration, and secondary infections. The molecular basis of the clinical symptoms of SSSS is well understood. ETs are serine proteases with high substrate specificity, which selectively recognize and hydrolyze desmosomal proteins in the skin. The fascinating road leading to the discovery of ETs as the agents responsible for SSSS and the characterization of the molecular mechanism of their action, including recent advances in the field, are reviewed in this article.

  5. The Heme Sensor System of Staphylococcus aureus

    OpenAIRE

    Stauff, Devin L; Skaar, Eric P.

    2009-01-01

    The important human pathogen Staphylococcus aureus is able to satisfy its nutrient iron requirement by acquiring heme from host hemoglobin in the context of infection. However, heme acquisition exposes S. aureus to heme toxicity. In order to detect the presence of toxic levels of exogenous heme, S. aureus is able to sense heme through the heme sensing system (HssRS) two-component system. Upon sensing heme, HssRS directly regulates the expression of the heme-regulated ABC transporter HrtAB, wh...

  6. Staphylococcus aureus infections in psittacine birds.

    Science.gov (United States)

    Hermans, K; Devriese, L A; De Herdt, P; Godard, C; Haesebrouck, F

    2000-10-01

    Staphylococcus aureus was isolated from internal organs of 13 different psittacine birds submitted for necropsy over a period of 6 years. The birds all had lesions consistent with septicaemia. S. aureus isolates included three different phage types. In seven of the 13 birds, concurrent infections with Chlamydophila species, Enterococcus hirae, Candida species, unidentified streptococci and coagulasenegative staphylococci were detected. One bird also had lesions of lymphoid leucosis. Few indications were found that staphylococcosis associated problems may spread epidemically. The present studies suggest that S. aureus is pathogenic for psittacine birds, although it does not seem to be a frequent cause of disease. PMID:19184832

  7. An Application of Six Sigma to Reduce Supplier Quality Cost

    Science.gov (United States)

    Gaikwad, Lokpriya Mohanrao; Teli, Shivagond Nagappa; Majali, Vijay Shashikant; Bhushi, Umesh Mahadevappa

    2016-01-01

    This article presents an application of Six Sigma to reduce supplier quality cost in manufacturing industry. Although there is a wider acceptance of Six Sigma in many organizations today, there is still a lack of in-depth case study of Six Sigma. For the present research the case study methodology was used. The company decided to reduce quality cost and improve selected processes using Six Sigma methodologies. Regarding the fact that there is a lack of case studies dealing with Six Sigma especially in individual manufacturing organization this article could be of great importance also for the practitioners. This paper discusses the quality and productivity improvement in a supplier enterprise through a case study. The paper deals with an application of Six Sigma define-measure-analyze-improve-control methodology in an industry which provides a framework to identify, quantify and eliminate sources of variation in an operational process in question, to optimize the operation variables, improve and sustain performance viz. process yield with well-executed control plans. Six Sigma improves the process performance (process yield) of the critical operational process, leading to better utilization of resources, decreases variations and maintains consistent quality of the process output.

  8. Multiple pathways for regulation of sigmaS (RpoS) stability in Escherichia coli via the action of multiple anti-adaptors.

    Science.gov (United States)

    Bougdour, Alexandre; Cunning, Christofer; Baptiste, Patrick Jean; Elliott, Thomas; Gottesman, Susan

    2008-04-01

    SigmaS, the stationary phase sigma factor of Escherichia coli and Salmonella, is regulated at multiple levels. The sigmaS protein is unstable during exponential growth and is stabilized during stationary phase and after various stress treatments. Degradation requires both the ClpXP protease and the adaptor RssB. The small antiadaptor protein IraP is made in response to phosphate starvation and interacts with RssB, causing sigmaS stabilization under this stress condition. IraP is essential for sigmaS stabilization in some but not all starvation conditions, suggesting the existence of other anti-adaptor proteins. We report here the identification of new regulators of sigmaS stability, important under other stress conditions. IraM (inhibitor of RssB activity during Magnesium starvation) and IraD (inhibitor of RssB activity after DNA damage) inhibit sigmaS proteolysis both in vivo and in vitro. Our results reveal that multiple anti-adaptor proteins allow the regulation of sigmaS stability through the regulation of RssB activity under a variety of stress conditions. PMID:18383615

  9. A TonB-Dependent Transporter Is Responsible for Methanobactin Uptake by Methylosinus trichosporium OB3b.

    Science.gov (United States)

    Gu, Wenyu; Farhan Ul Haque, Muhammad; Baral, Bipin S; Turpin, Erick A; Bandow, Nathan L; Kremmer, Elisabeth; Flatley, Andrew; Zischka, Hans; DiSpirito, Alan A; Semrau, Jeremy D

    2016-03-01

    Methanobactin, a small modified polypeptide synthesized by methanotrophs for copper uptake, has been found to be chromosomally encoded. The gene encoding the polypeptide precursor of methanobactin, mbnA, is part of a gene cluster that also includes several genes encoding proteins of unknown function (but speculated to be involved in methanobactin formation) as well as mbnT, which encodes a TonB-dependent transporter hypothesized to be responsible for methanobactin uptake. To determine if mbnT is truly responsible for methanobactin uptake, a knockout was constructed in Methylosinus trichosporium OB3b using marker exchange mutagenesis. The resulting M. trichosporium mbnT::Gm(r) mutant was found to be able to produce methanobactin but was unable to internalize it. Further, if this mutant was grown in the presence of copper and exogenous methanobactin, copper uptake was significantly reduced. Expression of mmoX and pmoA, encoding polypeptides of the soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO), respectively, also changed significantly when methanobactin was added, which indicates that the mutant was unable to collect copper under these conditions. Copper uptake and gene expression, however, were not affected in wild-type M. trichosporium OB3b, indicating that the TonB-dependent transporter encoded by mbnT is responsible for methanobactin uptake and that methanobactin is a key mechanism used by methanotrophs for copper uptake. When the mbnT::Gm(r) mutant was grown under a range of copper concentrations in the absence of methanobactin, however, the phenotype of the mutant was indistinguishable from that of wild-type M. trichosporium OB3b, indicating that this methanotroph has multiple mechanisms for copper uptake. PMID:26773085

  10. ER stress drives Lipocalin 2 upregulation in prostate cancer cells in an NF-κB-dependent manner

    International Nuclear Information System (INIS)

    Tumor cells adapt to endoplasmic reticulum (ER) stress through a set of conserved intracellular pathways, as part of a process termed the unfolded protein response (UPR). The expression of UPR genes/proteins correlates with increasing progression and poor clinical outcome of several tumor types, including prostate cancer. UPR signaling can activate NF-κB, a master regulator of transcription of pro-inflammatory, tumorigenic cytokines. Previous studies have shown that Lipocalin 2 (Lcn2) is upregulated in several epithelial cancers, including prostate cancer, and recently Lcn2 was implicated as a key mediator of breast cancer progression. Here, we hypothesize that the tumor cell UPR regulates Lcn2 production. We interrogated Lcn2 regulation in murine and human prostate cancer cells undergoing pharmacological and physiological ER stress, and tested UPR and NF-κB dependence by using pharmacological inhibitors of these signaling pathways. Induction of ER stress using thapsigargin (Tg), a canonical pharmacologic ER stress inducer, or via glucose deprivation, a physiologic ER stressor present in the tumor microenvironment, upregulates LCN2 production in murine and human prostate cancer cells. Inhibition of the UPR using 4-phenylbutyric acid (PBA) dramatically decreases Lcn2 transcription and translation. Inhibition of NF-κB in prostate cancer cells undergoing Tg-mediated ER stress by BAY 11-7082 abrogates Lcn2 upregulation. We conclude that the UPR activates Lcn2 production in prostate cancer cells in an NF-κB-dependent manner. Our results imply that the observed upregulation of Lipocalin 2 in various types of cancer cells may be the direct consequence of concomitant UPR activation, and that the ER stress/Lipocalin 2 axis is a potential new target for intervention in cancer progression

  11. Six Sigma process improvements in automotive parts production

    Directory of Open Access Journals (Sweden)

    M. Soković

    2006-09-01

    Full Text Available Purpose: of this paper: In the paper is presented a Six Sigma project, undertaken within company for production automotive parts, which deals with identification and reduction of production cost in the deburring process for gravity die-castings and improvement of quality level of produced parts.Design/methodology/approach: The objectives are achieved by application of Six Sigma approach to quality improvement project in automotive industry. The applied Six Sigma approach includes team works through several phases: Define, Measure, Analyze, Improve, and Control (DMAIC.Findings: Systematic application of Six Sigma DMAIC tools and methodology within an automotive parts production results with several achievements such are reduction of tools expenses, cost of poor quality and labours expenses.It was shown that Six sigma is an effective way to find out where are the greatest process needs and which are the softest points of the process. Also, Six sigma provide measurable indicators and adequate data for analytical analysis.Research implications: The possibility of application of several Six Sigma tools such are thought process mapping, Pareto diagrams, process mapping, cause and effect matrix, and analysis of variation and capability studies.Practical implications: Improvements through reduced Production time, Control time, Material and Internal scrap have been yield significant financial. Furthermore, this pilot project enabled introduction of Six Sigma methodology in wider range of manufacturer activities.Originality/value: The paper researches the possibility of Six Sigma application within manufacturing process. This paper is of the value to researcher in the field of quality management and quality improvement, as well as to professionals in the manufacturing industry, wherever the quality improvement is an issue.

  12. The sigma model on complex projective superspaces

    Energy Technology Data Exchange (ETDEWEB)

    Candu, Constantin; Mitev, Vladimir; Schomerus, Volker [DESY, Hamburg (Germany). Theory Group; Quella, Thomas [Amsterdam Univ. (Netherlands). Inst. for Theoretical Physics; Saleur, Hubert [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Physique Theorique; USC, Los Angeles, CA (United States). Physics Dept.

    2009-08-15

    The sigma model on projective superspaces CP{sup S-1} {sup vertical} {sup stroke} {sup S} gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle {theta}. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we propose a spin chain regularization of the CP{sup S-1} {sup vertical} {sup stroke} {sup S} model with open boundary conditions and use it to determine the spectrum at the conformal fixed point. The numerical results are in remarkable agreement with the continuum analysis. (orig.)

  13. Perturbation theory for string sigma models

    CERN Document Server

    Bianchi, Lorenzo

    2016-01-01

    In this thesis we investigate quantum aspects of the Green-Schwarz superstring in various AdS backgrounds relevant for the AdS/CFT correspondence, providing several examples of perturbative computations in the corresponding integrable sigma-models. We start by reviewing in details the supercoset construction of the superstring action in $AdS_5 \\times S^5$, pointing out the limits of this procedure for $AdS_4$ and $AdS_3$ backgrounds. For the $AdS_4 \\times CP^3$ case we give a thorough derivation of an alternative action, based on the double-dimensional reduction of eleven-dimensional super-membranes. We then consider the expansion about the BMN vacuum and the S-matrix for the scattering of worldsheet excitations in the decompactification limit. To evaluate its elements efficiently we describe a unitarity-based method resulting in a very compact formula yielding the cut-constructible part of any one-loop two-dimensional S-matrix. In the second part of this review we analyze the superstring action on $AdS_4 \\ti...

  14. The sigma model on complex projective superspaces

    International Nuclear Information System (INIS)

    The sigma model on projective superspaces CPS-1verticalstrokeS gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle θ. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we propose a spin chain regularization of the CPS-1verticalstrokeS model with open boundary conditions and use it to determine the spectrum at the conformal fixed point. The numerical results are in remarkable agreement with the continuum analysis. (orig.)

  15. The Sigma Model on Complex Projective Superspaces

    CERN Document Server

    Candu, Constantin; Quella, Thomas; Saleur, Hubert; Schomerus, Volker

    2009-01-01

    The sigma model on complex projective superspaces CP^{S-1|S} gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle \\theta. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we propose a spin chain regularization of the CP^{S-1|S} model with open boundary conditions and use it to determine the spect...

  16. The sigma model on complex projective superspaces

    Science.gov (United States)

    Candu, Constantin; Mitev, Vladimir; Quella, Thomas; Saleur, Hubert; Schomerus, Volker

    2010-02-01

    The sigma model on projective superspaces mathbb{C}{mathbb{P}^{S - 1left| S right.}} gives rise to a continuous family of interacting 2D conformal field theories which are parametrized by the curvature radius R and the theta angle θ. Our main goal is to determine the spectrum of the model, non-perturbatively as a function of both parameters. We succeed to do so for all open boundary conditions preserving the full global symmetry of the model. In string theory parlor, these correspond to volume filling branes that are equipped with a monopole line bundle and connection. The paper consists of two parts. In the first part, we approach the problem within the continuum formulation. Combining combinatorial arguments with perturbative studies and some simple free field calculations, we determine a closed formula for the partition function of the theory. This is then tested numerically in the second part. There we extend the proposal of [ arXiv:0908.1081 ] for a spin chain regularization of the mathbb{C}{mathbb{P}^{S - 1left| S right.}} model with open boundary conditions and use it to determine the spectrum at the conformal fixed point. The numerical results are in remarkable agreement with the continuum analysis.

  17. Laboratory Maintenance of Methicillin-Resistant Staphylococcus aureus (MRSA)

    OpenAIRE

    Nicholas P Vitko; Richardson, Anthony R.

    2013-01-01

    Staphylococcus aureus is an important bacterial pathogen in the hospital and community settings, especially Staphylococcus aureus clones that exhibit methicillin-resistance (MRSA). Many strains of S. aureus are utilized in the laboratory, underscoring the genetic differences inherent in clinical isolates. S. aureus grows quickly at 37°C with aeration in rich media (e.g. BHI) and exhibits a preference for glycolytic carbon sources. Furthermore, S. aureus has a gold pigmentation, exhibits β-hem...

  18. Scalar strangeness content of the nucleon and baryon sigma terms

    OpenAIRE

    Ren, Xiu-Lei; Geng, Li-Sheng; Meng, Jie

    2014-01-01

    The scalar strangeness content of the nucleon, characterized by the so-called strangeness-nucleon sigma term, is of fundamental importance in understanding its sea-quark flavor structure. We report a determination of the octet baryon sigma terms via the Feynman-Hellmann theorem by analyzing the latest high-statistics $n_f=2+1$ lattice QCD simulations with covariant baryon chiral perturbation theory up to next-to-next-to-next-to-leading order. In particular, we predict $\\sigma_{\\pi N}=55(1)(4)...

  19. On the sigma-model of deformed special geometry

    International Nuclear Information System (INIS)

    We discuss the deformed sigma-model that arises when considering four-dimensional N=2 abelian vector multiplets in the presence of an arbitrary chiral background field. In addition, we allow for a class of deformations of special geometry by non-holomorphic terms. We analyze the geometry of the sigma-model in terms of intrinsic torsion classes. We show that, generically, the deformed geometry is non-Kähler. We illustrate our findings with an example. We also express the deformed sigma-model in terms of the Hesse potential that underlies the real formulation of special geometry

  20. Sigma: Web Retrieval Interface for Nuclear Reaction Data

    Energy Technology Data Exchange (ETDEWEB)

    Pritychenko,B.; Sonzogni, A.A.

    2008-06-24

    The authors present Sigma, a Web-rich application which provides user-friendly access in processing and plotting of the evaluated and experimental nuclear reaction data stored in the ENDF-6 and EXFOR formats. The main interface includes browsing using a periodic table and a directory tree, basic and advanced search capabilities, interactive plots of cross sections, angular distributions and spectra, comparisons between evaluated and experimental data, computations between different cross section sets. Interactive energy-angle, neutron cross section uncertainties plots and visualization of covariance matrices are under development. Sigma is publicly available at the National Nuclear Data Center website at www.nndc.bnl.gov/sigma.

  1. Dissipative quantum dynamics and nonlinear sigma-model

    International Nuclear Information System (INIS)

    Sedov variational principle which is the generalization of the least action principle for the dissipative and irreversible processes and the classical dissipative mechanics in the phase space is considered. Quantum dynamics for the dissipative and irreversible processes is constructed. As an example of the dissipative quantum theory the nonlinear two-dimensional sigma-model is considered. The conformal anomaly of the energy momentum tensor trace for closed bosonic string on the affine-metric manifold is investigated. The two-loop metric beta-function for nonlinear dissipative sigma-model was calculated. The results are compared with the ultraviolet two-loop conterterms for affine-metric sigma model. 71 refs

  2. 6 Sigma DFSS technique which is easy to use

    International Nuclear Information System (INIS)

    This book gives descriptions of 6 sigma DFSS technique. The contents of this book are storm of change, way of problem and solution, importance of customer satisfaction, quality improvement is key of customer satisfaction, quality improvement equals cost cutting, quality aim in perfect level, finding basic cause, data is life, standardization is fundamentals of all activity for improvement, chief, Chang's house, collection of data, setting goal to improve, experiment is the best way, importance of the last step, x control power of 6 sigma and Let's go six-sigma.

  3. Heat Balanced Bolometer with Sigma-Delta Interface

    OpenAIRE

    Denoual, Matthieu; Pouliquen, Mathieu; Allègre, Gilles; Brouard, D.; Veith, A; De Sagazan, Olivier; Attia, Patrick

    2012-01-01

    This paper presents a single-loop 2nd order sigmadelta interface circuit for a bolometer operating in closed-loop mode. Switched capacitor circuitry is developed to implement the sigma-delta structure. The sigma-delta modulator acts both as digital readout circuit and as a mean of heat feedback. The design approach of the sigma-delta structure and the feedback shaping is explained. The circuit is designed for a realization in AMS CMOS 0.35μm technology.

  4. The Heme Sensor System of Staphylococcus aureus

    Science.gov (United States)

    Stauff, Devin L.; Skaar, Eric P.

    2016-01-01

    The important human pathogen Staphylococcus aureus is able to satisfy its nutrient iron requirement by acquiring heme from host hemoglobin in the context of infection. However, heme acquisition exposes S. aureus to heme toxicity. In order to detect the presence of toxic levels of exogenous heme, S. aureus is able to sense heme through the heme sensing system (HssRS) two-component system. Upon sensing heme, HssRS directly regulates the expression of the heme-regulated ABC transporter HrtAB, which alleviates heme toxicity. Importantly, the inability to sense or respond to heme alters the virulence of S. aureus, highlighting the importance of heme sensing and detoxification to staphylococcal pathogenesis. Furthermore, potential orthologues of the Hss and Hrt systems are found in many species of Gram-positive bacteria, a possible indication that heme stress is a challenge faced by bacteria whose habitats include host tissues rich in heme. PMID:19494582

  5. A lean Six Sigma team increases hand hygiene compliance and reduces hospital-acquired MRSA infections by 51%.

    Science.gov (United States)

    Carboneau, Clark; Benge, Eddie; Jaco, Mary T; Robinson, Mary

    2010-01-01

    A low hand hygiene compliance rate by healthcare workers increases hospital-acquired infections to patients. At Presbyterian Healthcare Services in Albuquerque, New Mexico a Lean Six Sigma team identified the reasons for noncompliance were multifaceted. The team followed the DMAIC process and completed the methodology in 12 months. They implemented multiple solutions in the three areas: Education, Culture, and Environment. Based on methicillin-resistant Staphylococcus aureus (MRSA) mortality research the team's results included an estimated 2.5 lives saved by reducing MRSA infections by 51%. Subsequently this 51% decrease in MRSA saved the hospital US$276,500. For those readers tasked with increasing hand hygiene compliance this article will provide the knowledge and insight needed to overcome multifaceted barriers to noncompliance. PMID:20618572

  6. Binding of heparan sulfate to Staphylococcus aureus.

    OpenAIRE

    Liang, O D; Ascencio, F; Fransson, L A; Wadström, T

    1992-01-01

    Heparan sulfate binds to proteins present on the surface of Staphylococcus aureus cells. Binding of 125I-heparan sulfate to S. aureus was time dependent, saturable, and influenced by pH and ionic strength, and cell-bound 125I-heparan sulfate was displaced by unlabelled heparan sulfate or heparin. Other glycosaminoglycans of comparable size (chondroitin sulfate and dermatan sulfate), highly glycosylated glycoprotein (hog gastric mucin), and some anionic polysaccharides (dextran sulfate and RNA...

  7. The Staphylococcus aureus “superbug”

    OpenAIRE

    FOSTER, TIMOTHY JAMES

    2004-01-01

    PUBLISHED There has been some debate about the disease-invoking potential of Staphylococcus aureus strains and whether invasive disease is associated with particularly virulent genotypes, or "superbugs." A study in this issue of the JCI describes the genotyping of a large collection of nonclinical, commensal S. aureus strains from healthy individuals in a Dutch population. Extensive study of their genetic relatedness by amplified restriction fragment typing and comparison with strains that...

  8. Transmissible mupirocin resistance in Staphylococcus aureus.

    OpenAIRE

    Rahman, M.; Noble, W. C.; Cookson, B

    1989-01-01

    The spread of two strains of Staphylococcus aureus with high level resistance to mupirocin is described. The resistance proved to be easily transferred to other S. aureus strains by filter mating experiments and on the skin of mice. No plasmid band corresponding to the resistance could be demonstrated by agarose gel electrophoresis or by caesium chloride gradient centrifugation but cleavage of 'chromosomal' DNA from resistant recipients showed bright bands of DNA absent from sensitive controls.

  9. Triclosan Promotes Staphylococcus aureus Nasal Colonization

    OpenAIRE

    Syed, Adnan K.; Ghosh, Sudeshna; Love, Nancy G.; Boles, Blaise R.

    2014-01-01

    ABSTRACT The biocide triclosan is used in many personal care products, including toothpastes, soaps, clothing, and medical equipment. Consequently, it is present as a contaminant in the environment and has been detected in some human fluids, including serum, urine, and milk. Staphylococcus aureus is an opportunistic pathogen that colonizes the noses and throats of approximately 30% of the population. Colonization with S. aureus is known to be a risk factor for several types of infection. Here...

  10. Biofilm formation-gene expression relay system in Escherichia coli: modulation of sigmaS-dependent gene expression by the CsgD regulatory protein via sigmaS protein stabilization.

    Science.gov (United States)

    Gualdi, Luciana; Tagliabue, Letizia; Landini, Paolo

    2007-11-01

    Bacteria can switch from a single-cell (planktonic) mode to a multicellular community (biofilm) mode via production of cell-cell aggregation and surface adhesion factors. In this report, we present evidence that the CsgD protein, a transcription regulator involved in biofilm formation in Escherichia coli, modulates the expression of the rpoS (sigma(S)) regulon. Protein pattern analysis of E. coli cells in stationary phase shows that CsgD affects the expression of several proteins encoded by sigma(S)-dependent genes. CsgD regulation of sigma(S)-dependent genes takes place at gene transcription level, does not bypass the need for rpoS, and is abolished in an rpoS-null mutant. Consistent with these results, we find that CsgD expression leads to an increase in sigma(S) intracellular concentration. Increase in sigma(S) cellular amount is mediated by CsgD-dependent transcription activation of iraP, encoding a factor involved in sigma(S) protein stabilization. Our results strongly suggest that the CsgD regulatory protein plays a major role as a relay between adhesion factors production and sigma(S)-dependent gene expression via sigma(S) protein stabilization. Direct coordination between biofilm formation and expression of the rpoS regulon could positively impact important biological processes, such as host colonization or response to environmental stresses. PMID:17873038

  11. The sigmaS subunit of RNA polymerase as a signal integrator and network master regulator in the general stress response in Escherichia coli.

    Science.gov (United States)

    Klauck, Eberhard; Typas, Athanasios; Hengge, Regine

    2007-01-01

    The sigmaS (RpoS) subunit of RNA polymerase in Escherichia coli is a key master regulator which allows this bacterial model organism and important pathogen to adapt to and survive environmentally rough times. While hardly present in rapidly growing cells, sigmaS strongly accumulates in response to many different stress conditions, partly replaces the vegetative sigma subunit in RNA polymerase and thereby reprograms this enzyme to transcribe sigmaS-dependent genes (up to 10% of the E. coli genes). In this review, we summarize the extremely complex regulation of sigmaS itself and multiple signal input at the level of this master regulator, we describe the way in which sigmaS specifically recognizes "stress" promoters despite their similarity to vegetative promoters, and, while being far from comprehensive, we give a short overview of the far-reaching physiological impact of sigmaS. With sigmaS being a central and multiple signal integrator and master regulator of hundreds of genes organized in regulatory cascades and sub-networks or regulatory modules, this system also represents a key model system for analyzing complex cellular information processing and a starting point for understanding the complete regulatory network of an entire cell. PMID:17725229

  12. Induction of extracytoplasmic function sigma factors in Bacillus subtilis cells with membranes of reduced phosphatidylglycerol content.

    Science.gov (United States)

    Hashimoto, Michihiro; Takahashi, Hiroaki; Hara, Yoshinori; Hara, Hiroshi; Asai, Kei; Sadaie, Yoshito; Matsumoto, Kouji

    2009-06-01

    The Bacillus subtilis gene pgsA, which codes for the phosphatidylglycerophosphate synthase that catalyzes the committed step for the synthesis of phosphatidylglycerol (PG), is essential since Pspac-pgsA cells require IPTG for growth. Removal of the inducer caused a dramatic decrease of PG content in the membranes of cells and retarded growth. At 60 min and 120 min after removal, it was reduced to 14.1% and 8.9% of total lipid, respectively, from an initial content of 28.1%. We conjectured that the activity of some extracytoplasmic function (ECF) sigma factors, most of which are caught and regulated directly by cognate transmembrane anti-sigma factors, are affected by altered lipid composition of the membranes. Induction of the activities of ECF sigma factors (sigma(M) and sigma(V)) was observed after removal of IPTG, though that of sigma(V) was small. But other ECF sigma factors (sigma(W), sigma(X), sigma(Y), sigma(YlaC) and sigma(Z)) and the general stress sigmas sigma(B) and sigma(I) were not induced. Especially sigma(M) was activated strongly with the reduction of PG content and sustained a high level of activity, in contrast to the transient activation in PG normal cells after exposure to high salinity. This study demonstrates a new relationship between the alterations of lipid composition in the membranes and the activation of ECF sigma factors. PMID:19745567

  13. Different roles for anti-sigma factors in siderophore signalling pathways of Pseudomonas aeruginosa.

    Science.gov (United States)

    Mettrick, Karla A; Lamont, Iain L

    2009-12-01

    Group IV (extracytoplasmic function) sigma factors direct the expression of a large number of regulons in bacteria. The activities of many Group IV sigma factors are inhibited by members of a family of anti-sigma factor proteins, with appropriate environmental signals causing the sigma factor to be released for interaction with core RNA polymerase and consequent transcription of target genes. One subgroup of Group IV sigmas directs expression of genes for uptake of siderophores (iron-chelating compounds) by Gram-negative bacteria. The activities of these sigma factors are controlled by anti-sigma factors that span the cytoplasmic membrane. Binding of siderophore by a receptor protein in the outer membrane results in signal transduction from the periplasmic portion to the cytoplasmic portion of the appropriate anti-sigma factor, with consequent activity of the cognate sigma factor and upregulation of the gene encoding the receptor protein. We have investigated receptor/anti-sigma/sigma factor signalling pathways for uptake of the siderophores ferrichrome and desferrioxamine by Pseudomonas aeruginosa. In these pathways the 'anti-sigma' proteins are normally required for sigma factor activity and the cytoplasmic parts of the 'anti-sigmas' have 'pro-sigma' activity. We suggest that the family of anti-sigma factor proteins may be better considered as 'sigma regulators'. PMID:19889096

  14. Establishing a Lean Six Sigma Program in Higher Education

    KAUST Repository

    Svensson, Carsten

    2013-09-12

    Purpose: The objective of this paper is a contribution to the body of Lean Six Sigma knowledge within the vertical of higher education institutions. The paper will review the initial phase of an implementation and highlight future challenges. Approach: The observations presented in this paper, originates from rolling out a large lean six sigma implementation at a newly established university. The paper is supported with secondary data from literature. Findings: The paper will discuss the challenges of applying the lean six sigma method in a complex transactional environment. Research limitations: This paper is based on an empirical study of a single instance and authors’ experiences as practitioners. Originality: This paper is the first description of what is believed to be one of the largest implementations of Lean Six Sigma in higher education.

  15. Comment on "Lattice determination of $\\Sigma$-$\\Lambda$ mixing"

    CERN Document Server

    Gal, Avraham

    2015-01-01

    A recent Lattice QCD (LQCD) calculation of $\\Sigma$-$\\Lambda$ mixing by the QCDSF-UKQCD Collaboration [Phys. Rev. D 91, 074512 (2015)] finds a mixing angle about half of that found from the Dalitz-Von Hippel (DvH) flavor SU(3) mass formula which relates the $\\Sigma$-$\\Lambda$ mixing matrix element to known octet baryon mass differences and which has been used widely to evaluate charge symmetry breaking effects in $\\Lambda$ hypernuclei. We show that the LQCD-calculated $\\Sigma$-$\\Lambda$ mixing matrix element and octet baryon masses satisfy the DvH mass formula, concluding thereby that a good LQCD evaluation of $\\Sigma$-$\\Lambda$ mixing requires an equally good reproduction of octet baryon mass differences which is yet to be demonstrated.

  16. Office of Research funds five students selected by Sigma Xi

    OpenAIRE

    Trulove, Susan

    2009-01-01

    Treating children with phobias, advancing dairy cow nutrition, protection of rainforest carnivores, community-based conservation, and cell behavior in plants are the student research projects selected by Sigma Xi for recognition and support.

  17. Quality and Competitiveness: A Lean Six Sigma Approach

    Directory of Open Access Journals (Sweden)

    Irina-Virginia Drăgulănescu

    2015-11-01

    Full Text Available Originally developed to improve the quality and production efficiency, Lean Six Sigma is now widely adopted in other non-manufacturing sectors such as financial, trade, services, etc. The methodology known as Lean Six Sigma combines the Six Sigma techniques, ‒ which allow companies to reduce manufacturing defects ‒ and the Lean Manufacturing principles, ‒ which help companies benefit from faster processing for lower costs and with superior quality. As a result of the research, the authors observed that, despite growing popularity and impressive outcomes obtained by some companies, the Lean Six Sigma model does not always offer the expected results. However, the research has shown that the analysed company, operating in the field of courier services has managed to boost productivity and competitiveness by implementing measures that generated added value.

  18. Noise Study of a Heat Balanced Sigma-Delta Bolometer

    OpenAIRE

    Denoual, Matthieu; Brouard, D.; Veith, A; Pouliquen, Mathieu; Attia, Patrick; Allègre, Gilles

    2013-01-01

    The paper presents the modeling of a heat balanced sigma-delta bolometer with Matlab Simulink®. In particular, the noise sources are modeled to enable the evaluation of the output measurement resolution.

  19. On D-branes from gauged linear sigma models

    International Nuclear Information System (INIS)

    We study both A-type and B-type D-branes in the gauged linear sigma model by considering worldsheets with boundary. The boundary conditions on the matter and vector multiplet fields are first considered in the large-volume phase/non-linear sigma model limit of the corresponding Calabi-Yau manifold, where we find that we need to add a contact term on the boundary. These considerations enable to us to derive the boundary conditions in the full gauged linear sigma model, including the addition of the appropriate boundary contact terms, such that these boundary conditions have the correct non-linear sigma model limit. Most of the analysis is for the case of Calabi-Yau manifolds with one Kaehler modulus (including those corresponding to hypersurfaces in weighted projective space), though we comment on possible generalisations

  20. POLARIMETRIC OBSERVATIONS OF {sigma} ORIONIS E

    Energy Technology Data Exchange (ETDEWEB)

    Carciofi, A. C.; Faes, D. M. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-900 Sao Paulo, SP (Brazil); Townsend, R. H. D. [Department of Astronomy, University of Wisconsin-Madison, Sterling Hall, 475 N. Charter Street, Madison, WI 53706 (United States); Bjorkman, J. E., E-mail: carciofi@usp.br [Ritter Observatory, Department of Physics and Astronomy, University of Toledo, Toledo, OH 43606 (United States)

    2013-03-20

    Some massive stars possess strong magnetic fields that confine plasma in the circumstellar environment. These magnetospheres have been studied spectroscopically, photometrically, and, more recently, interferometrically. Here we report on the first firm detection of a magnetosphere in continuum linear polarization, as a result of monitoring {sigma} Ori E at the Pico dos Dias Observatory. The non-zero intrinsic polarization indicates an asymmetric structure whose minor elongation axis is oriented 150. Degree-Sign 0 east of the celestial north. A modulation of the polarization was observed with a period of half of the rotation period, which supports the theoretical prediction of the presence of two diametrally opposed, corotating blobs of gas. A phase lag of -0.085 was detected between the polarization minimum and the primary minimum of the light curve, suggestive of a complex shape of the plasma clouds. We present a preliminary analysis of the data with the Rigidly Rotating Magnetosphere model, which could not reproduce simultaneously the photometric and polarimetric data. A toy model comprising two spherical corotating blobs joined by a thin disk proved more successful in reproducing the polarization modulation. With this model we were able to determine that the total scattering mass of the thin disk is similar to the mass of the blobs (2M{sub b}/M{sub d} = 1.2) and that the blobs are rotating counterclockwise on the plane of the sky. This result shows that polarimetry can provide a diagnostic of the geometry of clouds, which will serve as an important constraint for improving the Rigidly Rotating Magnetosphere model.

  1. Biochemical Pharmacology of the Sigma-1 Receptor.

    Science.gov (United States)

    Chu, Uyen B; Ruoho, Arnold E

    2016-01-01

    The sigma-1 receptor (S1R) is a 223 amino acid two transmembrane (TM) pass protein. It is a non-ATP-binding nonglycosylated ligand-regulated molecular chaperone of unknown three-dimensional structure. The S1R is resident to eukaryotic mitochondrial-associated endoplasmic reticulum and plasma membranes with broad functions that regulate cellular calcium homeostasis and reduce oxidative stress. Several multitasking functions of the S1R are underwritten by chaperone-mediated direct (and indirect) interactions with ion channels, G-protein coupled receptors and cell-signaling molecules involved in the regulation of cell growth. The S1R is a promising drug target for the treatment of several neurodegenerative diseases related to cellular stress. In vitro and in vivo functional and molecular characteristics of the S1R and its interactions with endogenous and synthetic small molecules have been discovered by the use of pharmacologic, biochemical, biophysical, and molecular biology approaches. The S1R exists in monomer, dimer, tetramer, hexamer/octamer, and higher oligomeric forms that may be important determinants in defining the pharmacology and mechanism(s) of action of the S1R. A canonical GXXXG in putative TM2 is important for S1R oligomerization. The ligand-binding regions of S1R have been identified and include portions of TM2 and the TM proximal regions of the C terminus. Some client protein chaperone functions and interactions with the cochaperone 78-kDa glucose-regulated protein (binding immunoglobulin protein) involve the C terminus. Based on its biochemical features and mechanisms of chaperone action the possibility that the S1R is a member of the small heat shock protein family is discussed. PMID:26560551

  2. Involvement of sigmaS accumulation in repression of the flhDC operon in acidic phospholipid-deficient mutants of Escherichia coli.

    Science.gov (United States)

    Uchiyama, Junji; Nobue, Yuka; Zhao, Hong; Matsuzaki, Hiroshi; Nagahama, Hideki; Matsuoka, Satoshi; Matsumoto, Kouji; Hara, Hiroshi

    2010-06-01

    Escherichia coli pgsA mutations, which cause acidic phospholipid deficiency, repress transcription of the flagellar master operon flhDC, and thus impair flagellar formation and motility. The molecular mechanism of the strong repression of flhDC transcription in the mutant cells, however, has not yet been clarified. In order to shed light on this mechanism we isolated genes which, when supplied in multicopy, suppress the repression of flhD, and found that three genes, gadW, metE and yeaB, were capable of suppression. Taking into account a previous report that gadW represses sigma(S) production, the level of sigma(S) in the pgsA3 mutant was examined. We found that pgsA3 cells had a high level of sigma(S) and that introduction of a gadW plasmid into pgsA3 cells did reduce the sigma(S) level. The pgsA3 cells exhibited a sharp increase in sigma(S) levels that can only be partially attributed to the slight increase in rpoS transcription; the largest part of the effect is due to a post-transcriptional accumulation of sigma(S). GadW in multicopy exerts its effect by post-transcriptionally downregulating sigma(S). YeaB and MetE in multicopy also exert their effect via sigma(S). Disruption of rpoS caused an increase of the flhD mRNA level, and induction from P(trc)-rpoS repressed the flhD mRNA level. The strong repression of flhD transcription in pgsA3 mutant cells is thus suggested to be caused by the accumulated sigma(S). PMID:20185506

  3. Measurement of $R =\\sigma_{L} /\\sigma_{T}$ in deep-inelastic scattering on nuclei

    CERN Document Server

    Airapetian, A; Amarian, M; Ammosov, V V; Aschenauer, E C; Avakian, R; Avetisian, A; Avetisian, E; Bailey, P; Baturin, V; Baumgarten, C; Beckmann, M; Belostotskii, S; Blok, H P; Böttcher, Helmut B; Borisov, A; Bouhali, O; Bouwhuis, M; Brack, J; Brauksiepe, S; Brüll, A; Brunn, I; Capitani, G P; Chiang Huan Ching; Ciullo, G; Court, G R; Dalpiaz, P F; De Leo, R; De Nardo, L; De Sanctis, E; Devitsin, E G; De Witt-Huberts, P K A; Di Nezza, P; Düren, M; Ehrenfried, M; Elalaoui-Moulay, A; Elbakian, G M; Ellinghaus, F; Elschenbroich, U; Ely, J; Fabbri, R; Fantoni, A; Feshchenko, A; Felawka, L; Fischer, H; Fox, B; Franz, J; Frullani, S; Gärber, Y; Gapienko, G S; Gapienko, V A; Garibaldi, F; Garutti, E; Gavrilov, G E; Gharibian, V; Graw, G; Grebenyuk, O; Green, P W; Greeniaus, L G; Gute, A; Haeberli, W; Hafidi, K; Hartig, M; Hasch, D; Heesbeen, D; Heinsius, F H; Henoch, M; Hertenberger, R; Hesselink, W H A; Holler, Y; Hommez, B; Yarygin, G; Izotov, A; Jackson, H E; Jgoun, A; Kaiser, R; Kinney, E R; Kiselev, A; Kitching, P; Königsmann, K C; Kolster, H; Kopytine, M L; Korotkov, V A; Kotik, E; Kozlov, V; Krauss, B; Krivokhizhin, V G; Lagamba, L; Lapikas, L; Laziev, A; Lenisa, P; Liebing, P; Lindemann, T; Lorenzon, W; Makins, N C R; Marukian, G; Masoli, F; Menden, F; Mexner, V; Meyners, N; Miklukho, O; Miller, C A; Muccifora, V; Nagaitsev, A P; Nappi, E; Naryshkin, Yu; Nass, A; Negodaeva, K; Nowak, Wolf-Dieter; Oganessyan, K; Ohsuga, H; Orlandi, G; Podyachev, S P; Potashov, S Yu; Potterveld, D H; Raithel, M; Reggiani, D; Reimer, P; Reischl, A; Reolon, A R; Rith, K; Rosner, G; Rostomyan, A; Ryckbosch, D; Sakemi, Y; Sanjiev, I; Sato, F; Savin, I; Scarlett, C; Schäfer, A; Schill, C; Schnell, G; Schüler, K P; Schwind, A; Seibert, J; Seitz, B; Shanidze, R G; Shibata, T A; Shutov, V B; Simani, M C; Sinram, K; Stancari, M D; Statera, M; Steffens, E; Steijger, J J M; Stewart, J; Stösslein, U; Suetsugu, K; Tanaka, H; Taroian, S P; Terkulov, A R; Tessarin, S; Thomas, E; Tkabladze, A V; Tytgat, M; Urciuoli, G M; van der Steenhoven, G; Van de Vyver, R; Vetterli, Martin C; Vikhrov, V V; Vincter, M G; Visser, J; Volmer, J; Weiskopf, C; Wendland, J; Wilbert, J; Wise, T; Yen, S; Yoneyama, S; Zihlmann, B; Zohrabyan, H G

    2002-01-01

    Cross section ratios for deep-inelastic scattering from $^3$He, $^{14}$N and $^{84}$Kr with respect to $^2$H have been measured by the HERMES collaboration at DESY using a 27.5 GeV positron beam. The data cover a range in the Bjorken scaling variable $x$ between 0.010 and 0.65, the negative squared four-momentum transfer $Q^2$ varies from 0.5 to 15 GeV$^2$, while at small values of $x$ and $Q^2$, the virtual photon polarisation parameter $\\epsilon$ extends to lower values than previous measurements. From the dependence of the data on $\\epsilon$, values for $R_A/R_D$ with $R$ the ratio $\\sigma_L / \\sigma_T$ of longitudinal to transverse DIS cross sections have been derived and found to be consistent with unity. %The data are compared to measurements performed by NMC, E665, and SLAC %on $^4$He and $^{12}$C, and are found to be different for %$x <$ 0.06 and $Q^2 <$ 1.5 GeV$^2$.

  4. Improved Nucleon Properties in the Extended Quark Sigma Model

    CERN Document Server

    Abu-Shady, M

    2013-01-01

    The quark sigma model describes the quarks interacting via exchange the pions and sigma meson fields. A new version of mesonic potential is suggested in the frame of some aspects of the quantum chromodynamics (QCD). The field equations have been solved in the mean-field approximation for the hedgehog baryon state. The obtained results are compared with previous works and other models. We conclude that the suggested mesonic potential successfully calculates nucleon properties.

  5. Conventional and Machine Learning Assisted High Sigma Analysis

    OpenAIRE

    Wu, Wei

    2016-01-01

    Statistical circuit simulation exhibits increasing importance for circuit designs under process variations. In particular, high sigma analysis is needed to optimize highly-duplicated standard cells, where an extremely rare circuit failure event could lead to catastrophe of the entire chip. Conventional importance sampling (IS) approaches perform high sigma analysis efficiently at low dimensionality, but perform poorly either when there are a larger number of process variation variables, or wh...

  6. Wilsonian renormalization group approach to N=2 supersymmetric sigma models

    International Nuclear Information System (INIS)

    We derive the Wilsonian renormalization group equation in two dimensional N=2 supersymmetric nonlinear sigma models. This equation reveals that these sigma models on compact Einstein Kaehler manifolds are asymptotically free. This result is general and does not depend on the specific forms of the Kaehler potentials. We also examine the renormalization group flow for a new model which connects two manifolds with different global symmetries. (author)

  7. A Comment on the Renormalization of the Nonlinear Sigma Model

    CERN Document Server

    Bettinelli, D; Quadri, A; Bettinelli, Daniele; Ferrari, Ruggero; Quadri, Andrea

    2007-01-01

    We consider the recently proposed renormalization procedure for the nonlinear sigma model, consisting in the recursive subtraction of the divergences in a symmetric fashion. We compare this subtraction with the conventional procedure in power counting renormalizable (PCR) theories. We argue that symmetric subtraction in the nonlinear sigma model does not follow the lore by which nonrenormalizable theories require an infinite number of parameter fixings. Our conclusion is that only two parameters can be consistently used as physical constants.

  8. Řízení Six Sigma projektů.

    OpenAIRE

    Dobeš, Petr

    2009-01-01

    Diploma thesis of "Management of Six Sigma projects" is dealing with possibilities of using this technique in specific continuous improvement projects. Main goal is to analyse tools of this method on real situation and proof that Six Sigma is usable to manage this kind of projects. This work will include necessary theoretical basics from project management scope based on generally approved PMBOK methodology. Part of this analysis will be concerned on comparison of PMBOK principles and Six Sig...

  9. Does the light and broad $\\sigma$(500) exist?

    CERN Document Server

    Törnqvist, N A

    1999-01-01

    The lightest scalar and pseudoscalar nonets are discussed within the framework of the broken U3$\\times$U3 linear sigma model, and it is shown that already at the tree level this model works remarkably well predicting scalar masses and couplings not far from present experimental values, when all parameters are fixed from the pseudoscalar masses and decay constants. It is argued that this strongly suggests that the light and very broad $\\sigma$ resonance exists near 500 MeV.

  10. Sistem Informasi Kinerja Layanan Laboratorium Medis dengan Metode Six Sigma

    OpenAIRE

    Anindita Kusumastuti Dewi; Ibnu Widiyanto

    2016-01-01

    Medical Laboratory currently holds a very important role in medicine. Evaluation of laboratory quality plays a very important to maintain accurate laboratory results. This study aims to design an information system performance based on the same perception of medical laboratory services from customers using Six Sigma methods and frameworks using ServQual questionnaire. Selection of Six Sigma itself is based on this method can measure the extent to which each process deviates from its purpose a...

  11. Quality management in enterprise using Six Sigma method

    OpenAIRE

    M. Spilka; M. Sakaluk; Kania, A.

    2012-01-01

    Purpose: The article includes characteristic of the extrusion moulding as the most popular method of the plastics processing industry. Statistical analysis and a test of explanation of cause of so-called foam collapsing in the chosen productive enterprise were presented. Six Sigma method was used to the problem solution.Design/methodology/approach: In this paper a detailed plan for implementation of Six Sigma quality management conception in order to eliminate the collapsing effect of polyeth...

  12. IMPROVE MACHINING PROCESS CAPABILITY BY USING SIX-SIGMA

    OpenAIRE

    Sanjit Ray; Prasun Das

    2011-01-01

    Abstract: Six-Sigma is an improvement strategy for achieving customer satisfaction by reducing variation and thus producing products and services better, faster and cheaper. This study presents a Six-Sigma project of an automotive plant illustrating how the DMAIC methodology and statistical techniques were applied to resolve the issue of manufacturing process capability. This project has substantially benefit ted the organization by reducing the variation of bore size of crank case, achieving...

  13. Diagnosing of Sustainable Competitive Advantage Using Six Sigma Methodology

    OpenAIRE

    Omar Rabee'a Mahdi; Mahmoud Khalid Almsafir

    2012-01-01

    In this paper six sigma method for diagnosing the sustainable competitive advantages in organizations wasproposed. The study used a survey strategy “self-administered questionnaire”, to collect the primary data. Thesample of the targeted population consists of 40 Doctors in public hygienic institutions in Iraq, with variousfunctions and from different managerial levels. The analysis shows that six sigma methods in the organization’soperations should be taken into consideration with necessary ...

  14. Recent results on nucleon sigma terms in lattice QCD

    International Nuclear Information System (INIS)

    It has proven a significant challenge to experiment and phenomenology to extract a precise values of the nucleon sigma terms. This difficulty opens the window for lattice QCD simulations to lead the field in resolving this aspect of nucleon structure. Here we report on recent advances in the extraction of nucleon sigma terms in lattice QCD. In particular, the strangeness component is now being resolved to a precision that far surpasses best phenomenological estimates.

  15. A heat balanced sigma-delta uncooled bolometer

    OpenAIRE

    Denoual, Matthieu; Brouard, D.; Veith, A; De Sagazan, Olivier; Pouliquen, Mathieu; Attia, Patrick; Lebrasseur, E.; Mita, Y.; Allègre, Gilles

    2014-01-01

    This paper describes a heat balanced bolometer with an integrated CMOS sigma-delta interface. The sigma-delta interface accomplishes both the analogue-to-digital conversion and the heat feedback and therefore no other digital core is required. The heat feedback is implemented using a capacitively coupled electrical substitution technique with a digitally modulated signal that enables feedback linearization. Proof of concept is experimentally demonstrated with a polymer-type resistive bolomete...

  16. The Process of Alignment Between Strategy and Six Sigma Projects

    OpenAIRE

    Gonçalves, Bianca Soares De Oliveira; Musetti, Marcel Andreotti

    2010-01-01

    Regarding the systematization proposal presented, one should emphasize the importance of having in the literature a systematic alignment of the strategy with Six Sigma projects, given that this alignment is essential to the success of the program. In addition, the proposal assists companies that are implementing the Six Sigma program to be successful in selecting improvement projects. It was not within the overall objective to present a comprehensive proposal for all the improvement actions, ...

  17. Literature study - Sigma phase in 316L and 304L

    International Nuclear Information System (INIS)

    A literature survey of the existence, formation and kinetics of the sigma phase has been made. It was early realised that the precipitation of the sigma phase and that of 23-carbide were intimately coupled, why both are treated. The mechanical properties of both 304L and 316L are highly affected by the presence of sigma phase. The dominating features are: Yield strength is reduced, due to reduced solution hardening, Deformation hardening increases, Ultimate tensile stress increases, due to the presence of a hard phase, Impact strength is generally decreased. This is however dependant on the microstructure and processing. There are conditions where the impact strength can increase due to crack deflection, Ductility is significantly reduced. An additional conclusion is that the Huey test is too a blunt and conservative instrument to identify sensitization, caused by sigma phase. In a material that contains ferrite in some form, before aging, 23-carbide will precipitate in all welded 304L and 316L steels according to the literature. It is also clear that the first carbide to form is very fine and is precipitated before the sigma phase. This has the consequence that welded and annealed weldments will show some sensitization from 23-carbide. It is also clear that the amount of 23-carbide reduces as the amount of sigma phase increases. The time to the start of the dissolution, which could decrease the level of sensitization, depends on temperature. This could for instance explain why there are examples of sensitized 30L steel that showed excellent corrosion resistance. Direct corrosion of the sigma phase is highly pH-dependant. The sμμma phase has little resistance against oxidizing acids. It is thus important to understand the coupling between the sensitization caused by the 23-carbide and the change in ductility caused by the 23-carbide with sigma phase present. This is in turn primarily depending on the carbon content and the ferrite content after welding

  18. Kinetics of sigma phase formation in a Duplex Stainless Steel

    Directory of Open Access Journals (Sweden)

    Rodrigo Magnabosco

    2009-09-01

    Full Text Available This work determines the kinetics of sigma phase formation in UNS S31803 Duplex Stainless Steel (DSS, describing the phase transformations that occur in isothermal aging between 700 and 900 ºC for time periods up to 1032 hours, allowing the determination of the Time-Temperature-Precipitation (TTP diagram for sigma phase and proposing a model to predict the kinetics of sigma phase formation using a Johnson-Mehl-Avrami (JMA type expression. The higher kinetics of sigma phase formation occurs at 850 ºC. However, isothermal aging between 700 and 900 ºC for time periods up to 1032 hours are not sufficient to the establishment of thermodynamic equilibrium. Activation energy for both nucleation and growth of sigma phase is determined (185 kJ.mol-1 and its value is equivalent to the activation energy for Cr diffusion in ferrite, indicating that diffusion of Cr is probably the major thermally activated process involved in sigma phase formation. The determined JMA type expression presents good fit with experimental data between 700 and 850 ºC.

  19. Six Sigma Project Selection Using Fuzzy TOPSIS Decision Making Approach

    Directory of Open Access Journals (Sweden)

    Rajeev Rathi

    2015-05-01

    Full Text Available Six Sigma is considered as a logical business strategy that attempts to identify and eliminate the defects or failures for improving the quality of product and processes. A decision on project selection in Six Sigma is always very critical; it plays a key role in successful implementation of Six Sigma. Selection of a right Six Sigma project is essentially important for an automotive company because it greatly influences the manufacturing costs. This paper discusses an approach for right Six Sigma project selection at an automotive industry using fuzzy logic based TOPSIS method. The fuzzy TOPSIS is a well recognized tool to undertake the fuzziness of the data involved in choosing the right preferences. In this context, evaluation criteria have been designed for selection of best alternative. The weights of evaluation criteria are calculated by using the MDL (modified digital logic method and final ranking is calculated through priority index obtained by using fuzzy TOPSIS method. In the selected case study, this approach has rightly helped to identify the right project for implementing Six Sigma for achieving improvement in productivity.

  20. Lean sigma--will it work for healthcare?

    Science.gov (United States)

    Bahensky, James A; Roe, Janet; Bolton, Romy

    2005-01-01

    The manufacturing industry has been using Lean Sigma for years in pursuit of continuous improvement to obtain a competitive advantage. The objectives of these efforts are to use the Lean techniques for reducing cycle times and the Six Sigma concepts for reducing product defects. The Iowa Business Council with several advocates worked with the University of Iowa Hospital and Clinics (UIHC) and two other Iowa hospitals to determine whether Lean Sigma is adaptable in healthcare. A team of 15 people at UIHC used the Kaizen Breakthrough Methodology over a five-day period in an aggressive identification and elimination of non-value added activities in Radiology CT scanning. The results exceeded the initial project objectives and indicated that Lean Sigma is applicable in healthcare. Overall, the Lean Sigma project increased revenue by approximately $750,000 per year. The Kaizen process proved to be successful and interesting. Within three days, the team installed new work flow processes. This implementation-oriented approach is what differentiates Lean Sigma from other quality improvement processes. PMID:15682675

  1. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    International Nuclear Information System (INIS)

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  2. Subneurotoxic copper(II)-induced NF-κB-dependent microglial activation is associated with mitochondrial ROS

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zhuqin; Yu, Fengxiang; Gong, Ping; Qiu, Yu; Zhou, Wei; Cui, Yongyao; Li, Juan, E-mail: lijuanpharm@gmail.com; Chen, Hongzhuan, E-mail: yaoli@shsmu.edu.cn

    2014-04-15

    Microglia-mediated neuroinflammation and the associated neuronal damage play critical roles in the pathogenesis of neurodegenerative disorders. Evidence shows an elevated concentration of extracellular copper(II) in the brains of these disorders, which may contribute to neuronal death through direct neurotoxicity. Here we explored whether extracellular copper(II) triggers microglial activation. Primary rat microglia and murine microglial cell line BV-2 cells were cultured and treated with copper(II). The content of tumor necrosis factor-α (TNF-α) and nitric oxide in the medium was determined. Extracellular hydrogen peroxide was quantified by a fluorometric assay with Amplex Red. Mitochondrial superoxide was measured by MitoSOX oxidation. At subneurotoxic concentrations, copper(II) treatment induced a dose- and time-dependent release of TNF-α and nitric oxide from microglial cells, and caused an indirect, microglia-mediated neurotoxicity that was blocked by inhibition of TNF-α and nitric oxide production. Copper(II)-initiated microglial activation was accompanied with reduced IkB-α expression as well as phosphorylation and translocation of nuclear factor-κB (NF-κB) p65 and was blocked by NF-κB inhibitors (BAY11-7082 and SC-514). Moreover, copper(II) treatment evoked a rapid release of hydrogen peroxide from microglial cells, an effect that was not affected by NADPH oxidase inhibitors. N-acetyl-cysteine, a scavenger of reactive oxygen species (ROS), abrogated copper(II)-elicited microglial release of TNF-α and nitric oxide and subsequent neurotoxicity. Importantly, mitochondrial production of superoxide, paralleled to extracellular release of hydrogen peroxide, was induced after copper(II) stimulation. Our findings suggest that extracellular copper(II) at subneurotoxic concentrations could trigger NF-κB-dependent microglial activation and subsequent neurotoxicity. NADPH oxidase-independent, mitochondria-derived ROS may be involved in this activation

  3. Observation of eta(c) decay into Sigma(+)(Sigma)over-bar(-) and (sic)(-)over bar>(+) final states

    NARCIS (Netherlands)

    Ablikim, M.; Achasov, M. N.; Albayrak, O.; Ambrose, D. J.; An, F. F.; An, Q.; Bai, J. Z.; Ban, Y.; Becker, J.; Bennett, J. V.; Bertani, M.; Bian, J. M.; Boger, E.; Bondarenko, O.; Boyko, I.; Briere, R. A.; Bytev, V.; Cai, X.; Cakir, O.; Calcaterra, A.; Cao, G. F.; Cetin, S. A.; Chang, J. F.; Chelkov, G.; Chen, G.; Chen, H. S.; Chen, J.C.; Chen, M.L.; Chen, S. J.; Chen, X.; Chen, Y.B.; Cheng, H. P.; Chu, Y. P.; Coccetti, F.; Cronin-Hennessy, D.; Dai, H. L.; Dai, J.P.; Dedovich, D.; Deng, Z. Y.; Denig, A.; Denysenko, I.; Destefanis, M.; Ding, W. M.; Ding, Y.; Dong, L. Y.; Dong, M. Y.; Du, S. X.; Fang, J.; Fang, S. S.; Fava, L.; Feldbauer, F.; Feng, C. Q.; Ferroli, R. B.; Fu, C. D.; Fu, J. L.; Gao, Y.; Geng, C.; Goetzen, K.; Gong, W. X.; Gradl, W.; Greco, M.; Gu, M. H.; Gu, Y. T.; Guan, Y. H.; Guo, A.Q.; Guo, L. B.; Guo, Y. P.; Han, Y. L.; Harris, F. A.; He, K. L.; He, M.; He, Z. Y.; Held, T.; Heng, Y. K.; Hou, Z. L.; Hu, H. M.; Hu, J. F.; Hu, T.; Huang, G. M.; Huang, G. S.; Huang, J.S.; Huang, X.T.; Huang, Y. P.; Hussain, T.; Ji, C. S.; Ji, Q.; Ji, Q. P.; Ji, X. B.; Ji, X. L.; Jiang, L.L.; Jiang, X. S.; Jiao, J. B.; Jiao, Z.; Jin, D. P.; Jin, S.; Jing, F. F.; Kalantar-Nayestanaki, N.; Kavatsyuk, M.; Kornicer, M.; Kuehn, W.; Lai, W.; Lange, J.S.; Li, C. H.; Li, Cheng; Li, Cui; Li, D. M.; Li, F.; Li, G.; Li, H.B.; Li, J. C.; Li, K.; Li, Lei; Li, Q. J.; Li, S.L.; Li, W. D.; Li, W. G.; Li, X. L.; Li, X. N.; Li, X. Q.; Li, X. R.; Li, Z. B.; Liang, H.; Liang, Y. F.; Liang, Y.T.; Liao, G.R.; Liao, X. T.; Liu, B. J.; Liu, Cheng; Liu, C.X.; Liu, C.Y.; Liu, F.H.; Liu, Fang; Liu, Feng; Liu, H.; Liu, H. H.; Liu, H. M.; Liu, H. W.; Liu, J. P.; Liu, K.Y.; Liu, Kai; Liu, P. L.; Liu, Q.; Liu, S. B.; Liu, X.; Liu, Y. B.; Liu, Z. A.; Liu, Zhiqiang; Liu, Zhiqing; Loehner, H.; Lu, G. R.; Lu, H. J.; Lu, J.G.; Lu, Q. W.; Lu, X. R.; Lu, Y. P.; Luo, C. L.; Luo, M. X.; Luo, T.; Luo, X.L.; Lv, M.; Ma, C.L.; Ma, F. C.; Ma, H. L.; Ma, Q. M.; Ma, S.; Ma, T.; Ma, X. Y.; Ma, Y.; Maas, F.E.; Maggiora, M.; Malik, Q. A.; Mao, Y. J.; Mao, Z. P.; Messchendorp, J. G.; Min, J.; Min, T. J.; Mitchell, R. E.; Mo, X. H.; Morales, C. Morales; Motzko, C.; Muchnoi, N. Yu; Muramatsu, H.; Nefedov, Y.; Nicholson, C.; Nikolaev, I. B.; Ning, Z.; Olsen, S. L.; Ouyang, Q.; Pacetti, S.; Park, J.W.; Pelizaeus, M.; Peng, H. P.; Peters, K.; Ping, J. L.; Ping, R. G.; Poling, R.; Prencipe, E.; Qi, M.; Qian, S.; Qiao, C. F.; Qin, X. S.; Qin, Y.; Qin, Z. H.; Qiu, J. F.; Rashid, K. H.; Rong, G.; Ruan, X. D.; Sarantsev, A.; Schaefer, B. D.; Schulze, J.; Shao, M.; Shen, C. P.; Shen, X. Y.; Sheng, H. Y.; Shepherd, M. R.; Song, X. Y.; Spataro, S.; Spruck, B.; Sun, D. H.; Sun, G. X.; Sun, J.F.; Sun, S. S.; Sun, Y.J.; Sun, Y.Z.; Sun, Z.J.; Sun, Z.T.; Tang, C.J.; Tang, X.; Tapan, I.; Thorndike, E. H.; Toth, D.; Ullrich, M.; Varner, G. S.; Wang, B.; Wang, B.Q.; Wang, D.; Wang, D.Y.; Wang, K.; Wang, L. L.; Wang, L. S.; Wang, M.; Wang, P.; Wang, P. L.; Wang, Q.; Wang, Q. J.; Wang, S. G.; Wang, X. L.; Wang, Y. D.; Wang, Y. F.; Wang, Y. Q.; Wang, Z.; Wang, Z. G.; Wang, Z.Y.; Wei, D. H.; Wei, J.B.; Weidenkaff, P.; Wen, Q. G.; Wen, S. P.; Wiedner, U.; Wu, L.H.; Wu, N.; Wu, S.X.; Wu, W.; Wu, Z.; Xia, L. G.; Xiao, Z. J.; Xie, Y. G.; Xiu, Q. L.; Xu, G. F.; Xu, G. M.; Xu, H.; Xu, Q.J.; Xu, X. P.; Xu, Z. R.; Xue, F.; Xue, Z.; Yan, L.; Yan, W. B.; Yan, Y. H.; Yang, H. X.; Yang, Y.; Yang, Y. X.; Ye, H.; Ye, M.; Ye, M. H.; Yu, B. X.; Yu, C. X.; Yu, H. W.; Yu, J. S.; Yu, S. P.; Yuan, C. Z.; Yuan, Y.; Zafar, A. A.; Zallo, A.; Zeng, Y.; Zhang, B. X.; Zhang, B. Y.; Zhang, C.; Zhang, C. C.; Zhang, D. H.; Zhang, H. H.; Zhang, H. Y.; Zhang, J. Q.; Zhang, J. W.; Zhang, J. Y.; Zhang, J. Z.; Zhang, S. H.; Zhang, X. J.; Zhang, X. Y.; Zhang, Y.; Zhang, Y. H.; Zhang, Y. S.; Zhang, Z. P.; Zhang, Z. Y.; Zhao, G.; Zhao, H. S.; Zhao, J.W.; Zhao, K. X.; Zhao, Lei; Zhao, Ling; Zhao, M. G.; Zhao, Q.; Zhao, Q. Z.; Zhao, S.J.; Zhao, T.C.; Zhao, X. H.; Zhao, Y. B.; Zhao, Z. G.; Zhemchugov, A.; Zheng, B.; Zheng, Y. H.; Zhong, B.; Zhong, J.; Zhong, Z.; Zhou, L.; Zhou, X. K.; Zhou, X.R.; Zhu, C.; Zhu, K.; Zhu, K. J.; Zhu, S.H.; Zhu, Stuart; Zhu, Y.C.; Zhu, Y.M.; Zhu, Y.S.; Zhu, Z. A.; Zhuang, J.; Zou, B. S.; Zou, J. H.; Werner, M.J.; Zheng, J.P.

    2013-01-01

    Using a data sample of 2.25 x 10(8) J/psi events collected with the BESIII detector, we present the first observation of the decays of eta(c) mesons to Sigma(+)(Sigma) over bar (-) and (sic)(-)(+) .The branching fractions are measured to be (2.11 +/- 0.28(stat) +/- 0.18(syst) +/- 0.50(PDG)) x 10(-3)

  4. The sigma factor sigma s affects antibiotic production and biological control activity of Pseudomonas fluorescens Pf-5.

    OpenAIRE

    Sarniguet, A.; Kraus, J.; Henkels, M D; Muehlchen, A M; Loper, J E

    1995-01-01

    Pseudomonas fluorescens Pf-5, a rhizosphere-inhabiting bacterium that suppresses several soilborne pathogens of plants, produces the antibiotics pyrrolnitrin, pyoluteorin, and 2,4-diacetylphloroglucinol. A gene necessary for pyrrolnitrin production by Pf-5 was identified as rpoS, which encodes the stationary-phase sigma factor sigma s. Several pleiotropic effects of an rpoS mutation in Escherichia coli also were observed in an RpoS- mutant of Pf-5. These included sensitivities of stationary-p...

  5. Genome-wide analysis of the general stress response network in Escherichia coli: sigmaS-dependent genes, promoters, and sigma factor selectivity.

    Science.gov (United States)

    Weber, Harald; Polen, Tino; Heuveling, Johanna; Wendisch, Volker F; Hengge, Regine

    2005-03-01

    The sigmaS (or RpoS) subunit of RNA polymerase is the master regulator of the general stress response in Escherichia coli. While nearly absent in rapidly growing cells, sigmaS is strongly induced during entry into stationary phase and/or many other stress conditions and is essential for the expression of multiple stress resistances. Genome-wide expression profiling data presented here indicate that up to 10% of the E. coli genes are under direct or indirect control of sigmaS and that sigmaS should be considered a second vegetative sigma factor with a major impact not only on stress tolerance but on the entire cell physiology under nonoptimal growth conditions. This large data set allowed us to unequivocally identify a sigmaS consensus promoter in silico. Moreover, our results suggest that sigmaS-dependent genes represent a regulatory network with complex internal control (as exemplified by the acid resistance genes). This network also exhibits extensive regulatory overlaps with other global regulons (e.g., the cyclic AMP receptor protein regulon). In addition, the global regulatory protein Lrp was found to affect sigmaS and/or sigma70 selectivity of many promoters. These observations indicate that certain modules of the sigmaS-dependent general stress response can be temporarily recruited by stress-specific regulons, which are controlled by other stress-responsive regulators that act together with sigma70 RNA polymerase. Thus, not only the expression of genes within a regulatory network but also the architecture of the network itself can be subject to regulation. PMID:15716429

  6. Analysis of the vertexes $\\Omega^*_Q\\Omega_Q^*\\phi$, $\\Omega^*_Q\\Xi_Q^*K^*$, $\\Xi_Q^*\\Sigma^*_QK^*$ and $\\Sigma_Q^*\\Sigma^*_Q \\rho$ with the light-cone QCD sum rules

    OpenAIRE

    Wang, Zhi-Gang; Li, Jun-Fang

    2010-01-01

    In this article, we parameterize the vertexes $\\Omega^*_Q\\Omega_Q^*\\phi$, $\\Omega^*_Q\\Xi_Q^*K^*$, $\\Xi_Q^*\\Sigma^*_QK^*$ and $\\Sigma_Q^*\\Sigma^*_Q \\rho$ with four tensor structures due to Lorentz invariance, and study the corresponding four strong coupling constants with the light-cone QCD sum rules.

  7. Distribution and functions of TonB-dependent transporters in marine bacteria and environments: implications for dissolved organic matter utilization.

    Directory of Open Access Journals (Sweden)

    Kai Tang

    Full Text Available BACKGROUND: Bacteria play critical roles in marine nutrient cycles by incorporating and redistributing dissolved organic matter (DOM and inorganic nutrients in the ocean. TonB-dependent transporter (TBDT proteins allow Gram-negative bacteria to take up scarce resources from nutrient-limiting environments as well as siderophores, heme, vitamin B12, and recently identified carbohydrates. Thus, the characterization of TBDT distribution and functions is essential to better understand the contribution TBDT to DOM assimilation and its consequences on nutrient cycling in the environment. METHODOLOGY/PRINCIPAL FINDINGS: This study presents the distribution of encoded known and putative TBDT proteins in the genomes of microorganisms and from the Global Ocean Survey data. Using a Lek clustering algorithm and substrate specificities, the TBDT sequences were mainly classified into the following three groups: (1 DOM transporters; (2 Siderophores/Vitamins transporters; and (3 Heme/Hemophores/Iron(heme-binding protein transporters. Diverse TBDTs were found in the genomes of oligotroph Citromicrobium bathyomarinum JL354 and Citromicrobium sp JLT1363 and were highly expressed in the stationary phase of bacterial growth. The results show that the Gammaproteobacteria and the Cytophaga-Flavobacterium-Bacteroides (CFB group bacteria accounted for the majority of the TBDT gene pool in marine surface waters. CONCLUSIONS/SIGNIFICANCE: The results of this study confirm the ecological importance of TBDTs in DOM assimilation for bacteria in marine environments owing to a wide range of substrate utilization potential in the ubiquitous Gammaproteobacteria and CFB group bacteria.

  8. Acetylation of p65 at lysine 314 is important for late NF-κB-dependent gene expression

    Directory of Open Access Journals (Sweden)

    Hottiger Michael O

    2010-01-01

    Full Text Available Abstract Background NF-κB regulates the expression of a large number of target genes involved in the immune and inflammatory response, apoptosis, cell proliferation, differentiation and survival. We have earlier reported that p65, a subunit of NF-κB, is acetylated in vitro and in vivo at three different lysines (K310, K314 and K315 by the histone acetyltransferase p300. Results In this study, we describe that site-specific mutation of p65 at lysines 314 and 315 enhances gene expression of a subset of NF-κB target genes including Mmp10 and Mmp13. Increased gene expression was mainly observed three hours after TNFα stimulation. Chromatin immunoprecipitation (ChIP experiments with an antibody raised against acetylated lysine 314 revealed that chromatin-bound p65 is indeed acetylated at lysine 314. Conclusions Together, our results establish acetylation of K314 as an important regulatory modification of p65 and subsequently of NF-κB-dependent gene expression.

  9. Vinpocetine inhibits NF-kappaB-dependent inflammation via an IKK-dependent but PDE-independent mechanism.

    Science.gov (United States)

    Jeon, Kye-Im; Xu, Xiangbin; Aizawa, Toru; Lim, Jae Hyang; Jono, Hirofumi; Kwon, Dong-Seok; Abe, Jun-Ichi; Berk, Bradford C; Li, Jian-Dong; Yan, Chen

    2010-05-25

    Inflammation is a hallmark of many diseases, such as atherosclerosis, chronic obstructive pulmonary disease, arthritis, infectious diseases, and cancer. Although steroids and cyclooxygenase inhibitors are effective antiinflammatory therapeutical agents, they may cause serious side effects. Therefore, developing unique antiinflammatory agents without significant adverse effects is urgently needed. Vinpocetine, a derivative of the alkaloid vincamine, has long been used for cerebrovascular disorders and cognitive impairment. Its role in inhibiting inflammation, however, remains unexplored. Here, we show that vinpocetine acts as an antiinflammatory agent in vitro and in vivo. In particular, vinpocetine inhibits TNF-alpha-induced NF-kappaB activation and the subsequent induction of proinflammatory mediators in multiple cell types, including vascular smooth muscle cells, endothelial cells, macrophages, and epithelial cells. We also show that vinpocetine inhibits monocyte adhesion and chemotaxis, which are critical processes during inflammation. Moreover, vinpocetine potently inhibits TNF-alpha- or LPS-induced up-regulation of proinflammatory mediators, including TNF-alpha, IL-1beta, and macrophage inflammatory protein-2, and decreases interstitial infiltration of polymorphonuclear leukocytes in a mouse model of TNF-alpha- or LPS-induced lung inflammation. Interestingly, vinpocetine inhibits NF-kappaB-dependent inflammatory responses by directly targeting IKK, independent of its well-known inhibitory effects on phosphodiesterase and Ca(2+) regulation. These studies thus identify vinpocetine as a unique antiinflammatory agent that may be repositioned for the treatment of many inflammatory diseases. PMID:20448200

  10. Potassium Uptake Modulates Staphylococcus aureus Metabolism.

    Science.gov (United States)

    Gries, Casey M; Sadykov, Marat R; Bulock, Logan L; Chaudhari, Sujata S; Thomas, Vinai C; Bose, Jeffrey L; Bayles, Kenneth W

    2016-01-01

    As a leading cause of community-associated and nosocomial infections, Staphylococcus aureus requires sophisticated mechanisms that function to maintain cellular homeostasis in response to its exposure to changing environmental conditions. The adaptation to stress and maintenance of homeostasis depend largely on membrane activity, including supporting electrochemical gradients and synthesis of ATP. This is largely achieved through potassium (K(+)) transport, which plays an essential role in maintaining chemiosmotic homeostasis, affects antimicrobial resistance, and contributes to fitness in vivo. Here, we report that S. aureus Ktr-mediated K(+) uptake is necessary for maintaining cytoplasmic pH and the establishment of a proton motive force. Metabolite analyses revealed that K(+) deficiency affects both metabolic and energy states of S. aureus by impairing oxidative phosphorylation and directing carbon flux toward substrate-level phosphorylation. Taken together, these results underline the importance of K(+) uptake in maintaining essential components of S. aureus metabolism. IMPORTANCE Previous studies describing mechanisms for K(+) uptake in S. aureus revealed that the Ktr-mediated K(+) transport system was required for normal growth under alkaline conditions but not under neutral or acidic conditions. This work focuses on the effect of K(+) uptake on S. aureus metabolism, including intracellular pH and carbon flux, and is the first to utilize a pH-dependent green fluorescent protein (GFP) to measure S. aureus cytoplasmic pH. These studies highlight the role of K(+) uptake in supporting proton efflux under alkaline conditions and uncover a critical role for K(+) uptake in establishing efficient carbon utilization. PMID:27340697

  11. Regulation of sigma S degradation in Salmonella enterica var typhimurium: in vivo interactions between sigma S, the response regulator MviA(RssB) and ClpX.

    Science.gov (United States)

    Moreno, M; Audia, J P; Bearson, S M; Webb, C; Foster, J W

    2000-04-01

    The alternate sigma factor sigmaS plays an important role in the survival of Salmonella typhimurium following sudden encounters with a variety of stress conditions. The level of sigmaS is very low in rapidly growing cells but dramatically increases as those cells encounter environmental stress or enter into stationary phase. This increase is due in large measure to the stabilization of sigmaS protein against degradation by the ClpXP protease. The MviA protein, also known as RssB or SprE in Escherichia coli, is a putative member of a two component signal transduction system that plays a central role in facilitating sigmaS degradation by ClpXP. In contrast to most two-component systems, MviA does not appear to regulate gene expression but is believed to interact directly with sigmaS and somehow facilitate degradation. We now provide evidence that MviA(RssB) directly interacts both with sigmaS and ClpX in vivo, presumably enabling presentation of sigmaS to the ClpP protease. Interactions were demonstrated using a bacterial two-hybrid system in which sigmaS, MviA, and ClpX were fused to separate moieties of Bordetella pertussis CyaA (adenylate cyclase). Paired hybrid plasmids containing Cya'-MviA/RpoS-'Cya or Cya'-MviA/ClpX-'Cya successfully reconstituted adenylate cyclase activity in both S. typhimurium and E. coli. However, no direct interactions were detected between ClpX and RpoS. A second series of experiments has indicated that the interaction between MviA and sigmaS requires the N-terminus but not the C-terminus of MviA. Cellular levels of MviA appear to be very low in the cell based on lacZ fusion, Western blot and Northern blot analyses suggesting a catalytic role for MviA in sigmaS degradation. Mutagenesis of MviA residue D58, a canonical residue subject to phosphorylation in many two-component systems, decreased the ability of MviA to facilitate sigmaS turnover in vivo confirming that phosphorylation of MviA increases MviA activity. PMID:10939250

  12. Intra-cellular Staphylococcus aureus alone causes infection in vivo

    Directory of Open Access Journals (Sweden)

    T Hamza

    2013-07-01

    Full Text Available Chronic and recurrent bone infections occur frequently but have not been explained. Staphylococcus aureus (S. aureus is often found among chronic and recurrent infections and may be responsible for such infections. One possible reason is that S. aureus can internalize and survive within host cells and by doing so, S. aureus can evade both host defense mechanisms and most conventional antibiotic treatments. In this study, we hypothesized that intra-cellular S. aureus could induce infections in vivo. Osteoblasts were infected with S. aureus and, after eliminating extra-cellular S. aureus, inoculated into an open fracture rat model. Bacterial cultures and radiographic observations at post-operative day 21 confirmed local bone infections in animals inoculated with intra-cellular S. aureus within osteoblasts alone. We present direct in vivo evidence that intra-cellular S. aureus could be sufficient to induce bone infection in animals; we found that intra-cellular S. aureus inoculation of as low as 102 colony forming units could induce severe bone infections. Our data may suggest that intra-cellular S. aureus can “hide” in host cells during symptom-free periods and, under certain conditions, they may escape and lead to infection recurrence. Intra-cellular S. aureus therefore could play an important role in the pathogenesis of S. aureus infections, especially those chronic and recurrent infections in which disease episodes may be separated by weeks, months, or even years.

  13. Sigma metrics in clinical chemistry laboratory – A guide to quality control

    OpenAIRE

    Usha S. Adiga; A. Preethika; K.Swathi

    2015-01-01

    Background: Six sigma is a process of quality measurement and improvement program used in industries. Sigma methodology can be applied wherever an outcome of a process is to be measured. A poor outcome is counted as an error or defect. This is quantified as defects per million (DPM). Six sigma provides a more quantitative frame work for evaluating process performance with evidence for process improvement and describes how many sigma fit within the tolerance limits. Sigma metrics can be used e...

  14. RpoS (Sigma-S) Controls Expression of rsmA, a Global Regulator of Secondary Metabolites, Harpin, and Extracellular Proteins in Erwinia carotovora†

    OpenAIRE

    Mukherjee, Asita; Cui, Yaya; Ma, Weilei; Liu, Yang; Ishihama, Akira; Eisenstark, Abraham; Chatterjee, Arun K.

    1998-01-01

    RpoS (sigma-S or sigma-38) controls a large array of genes that are expressed during stationary phase and under various stress conditions in Escherichia coli and other bacteria. We document here that plant pathogenic and epiphytic Erwinia species, such as E. amylovora; E. carotovora subsp. atroseptica, betavasculorum, and carotovora; E. chrysanthemi; E. herbicola; E. rhapontici; and E. stewartii, possess rpoS genes and produce the alternate sigma factor. We show that rpoS transcription in E. ...

  15. Effects of H-NS and potassium glutamate on sigmaS- and sigma70-directed transcription in vitro from osmotically regulated P1 and P2 promoters of proU in Escherichia coli.

    OpenAIRE

    Rajkumari, K; Kusano, S.; Ishihama, A; Mizuno, T; Gowrishankar, J

    1996-01-01

    We have used supercoiled DNA templates in this study to demonstrate that transcription in vitro from the P1 and P2 promoters of the osmoresponsive proU operon of Escherichia coli is preferentially mediated by the sigma(s) and sigma70-bearing RNA polymerase holoenzymes, respectively. Addition of potassium glutamate resulted in the activation of transcription from both P1 and P2 and also led to a pronounced enhancement of sigma(s) selectivity at the P1 promoter. Transcription from P2, and to a ...

  16. EWS-FLI1 inhibits TNFα-induced NFκB-dependent transcription in Ewing sarcoma cells

    International Nuclear Information System (INIS)

    Research highlights: → EWS-FLI1 interferes with TNF-induced activation of NFκB in Ewing sarcoma cells. → EWS-FLI1 knockdown in Ewing sarcoma cells increases TNF-induced NFκB binding to DNA. → EWS-FLI1 reduces TNF-stimulated NFκB-dependent transcriptional activation. → Constitutive NFκB activity is not affected by EWS-FLI1. → EWS-FLI1 physically interacts with NFκB p65 in vivo. -- Abstract: Ewing sarcoma is primarily caused by a t(11;22) chromosomal translocation encoding the EWS-FLI1 fusion protein. To exert its oncogenic function, EWS-FLI1 acts as an aberrant transcription factor, broadly altering the gene expression profile of tumor cells. Nuclear factor-kappaB (NFκB) is a tightly regulated transcription factor controlling cell survival, proliferation and differentiation, as well as tumorigenesis. NFκB activity is very low in unstimulated Ewing sarcoma cells, but can be induced in response to tumor necrosis factor (TNF). We wondered whether NFκB activity could be modulated by EWS-FLI1 in Ewing sarcoma. Using a knockdown approach in Ewing sarcoma cells, we demonstrated that EWS-FLI1 has no influence on NFκB basal activity, but impairs TNF-induced NFκB-driven transcription, at least in part through inhibition of NFκB binding to DNA. We detected an in vivo physical interaction between the fusion protein and NFκB p65, which could mediate these effects. Our findings suggest that, besides directly controlling the activity of its primary target promoters, EWS-FLI1 can also indirectly influence gene expression in tumor cells by modulating the activity of key transcription factors such as NFκB.

  17. Sistem Informasi Kinerja Layanan Laboratorium Medis dengan Metode Six Sigma

    Directory of Open Access Journals (Sweden)

    Anindita Kusumastuti Dewi

    2016-01-01

    Full Text Available Medical Laboratory currently holds a very important role in medicine. Evaluation of laboratory quality plays a very important to maintain accurate laboratory results. This study aims to design an information system performance based on the same perception of medical laboratory services from customers using Six Sigma methods and frameworks using ServQual questionnaire. Selection of Six Sigma itself is based on this method can measure the extent to which each process deviates from its purpose as well as to reduce the variation of each of the attributes.  Six Sigma DMAIC namely (Define, Measure, Analyze, Improve, Control preferred because the end result will not yield new products, but only improvements on existing processes. The results of this calculation will be presented in the form of a dashboard for easier management in understanding the results of the evaluation. From the system can be obtained an average value of consumer perceptions terhdap performance today is 2,883, consumer expectations on the performance of 3.3768, the gap between the perceptions and expectations of consumers is -0.4936, customer satisfaction will be the performance of the current 85.37%, the value of 423 360 DPMO and sigma value there at the 2.07664 level.   Keywords: Laboratory Performance; Six Sigma; Servqual; Dashboard

  18. First measurement of $\\sigma_8$ using supernova data only

    CERN Document Server

    Castro, Tiago

    2014-01-01

    A method was recently proposed which allows the conversion of the weak-lensing effects in the supernova Hubble diagram from noise into signal. Such signal is sensitive to the growth of structure in the universe, and in particular can be used as a measurement of $\\sigma_8$ which is independent from more traditional methods such as those based on the CMB, cosmic shear or cluster abundance. We extend here that analysis to allow for intrinsic non-Gaussianities in the supernova PDF, and discuss how this can be best modelled using the Bayes Factor. Although it was shown that a precise measurement of $\\sigma_8$ requires ~$10^5$ supernovae, current data already allows an important proof of principle. In particular we make use of the 732 supernovae with z < 1 of the recent JLA catalog and show that a simple treatment of intrinsic non-Gaussianities with a couple of nuisance parameters is enough for our method to yield the values $\\sigma_8 = 0.84^{+0.28}_{-0.65}$ or $\\sigma_8 < 1.45$ at a $2\\sigma$ confidence leve...

  19. APLIKASI SIX SIGMA PADA PRODUK CLEAR FILE DI PERUSAHAAN STATIONARY

    Directory of Open Access Journals (Sweden)

    Desy Emilasari

    2007-01-01

    Full Text Available This paper describes the application of the Six Sigma methods is used in order to improve quality in manufacturing company that produce stationary product. DMAIC approach is utilized to analyze and improve 'Pocket Clear File' product since this product has more variability and defects. Quality improvement also monitor the process that influenced pocket defect in Bag Making, Kami-ire, Karidome, and Pocket after Karidome Inspections section. Determining of Six Sigma project is based in process and defect type in each section. FMEA also gave the recommendation for quality improvement we need to evaluate the final result of the improvement since some of them were not working properly. Abstract in Bahasa Indonesia : Paper ini menggambarkan bagaimana aplikasi metode Six Sigma digunakan untuk melakukan perbaikan kualitas pada perusahaan manufaktur yang memproduksi produk stationary. Pendekatan DMAIC dipakai untuk menganalisa dan melakukan perbaikan produk 'Pocket Clear File' karena tingginya variabilitas dan cacat dibanding produk lain. Perbaikan kualitas juga memperhatikan proses yang mempengaruhi terjadinya cacat pocket pada section Bag Making, Kami-ire, Karidome, dan Pocket after Karidome Inspection. Penentuan proyek Six Sigma didasarkan atas proses dan jenis cacat pada setiap section. Pendekatan FMEA mampu memberi rekomendasi perbaikan kualitas. Evaluasi dari hasil perbaikan penting untuk dilakukan karena beberapa implementasi perbaikan kualitas tidak berjalan sesuai dengan rencana. kata kunci: six sigma, DMAIC, perusahaan stationary.

  20. Functional modules of sigma factor regulons guarantee adaptability and evolvability

    Science.gov (United States)

    Binder, Sebastian C.; Eckweiler, Denitsa; Schulz, Sebastian; Bielecka, Agata; Nicolai, Tanja; Franke, Raimo; Häussler, Susanne; Meyer-Hermann, Michael

    2016-02-01

    The focus of modern molecular biology turns from assigning functions to individual genes towards understanding the expression and regulation of complex sets of molecules. Here, we provide evidence that alternative sigma factor regulons in the pathogen Pseudomonas aeruginosa largely represent insulated functional modules which provide a critical level of biological organization involved in general adaptation and survival processes. Analysis of the operational state of the sigma factor network revealed that transcription factors functionally couple the sigma factor regulons and significantly modulate the transcription levels in the face of challenging environments. The threshold quality of newly evolved transcription factors was reached faster and more robustly in in silico testing when the structural organization of sigma factor networks was taken into account. These results indicate that the modular structures of alternative sigma factor regulons provide P. aeruginosa with a robust framework to function adequately in its environment and at the same time facilitate evolutionary change. Our data support the view that widespread modularity guarantees robustness of biological networks and is a key driver of evolvability.

  1. A Lean Six Sigma program in higher education

    KAUST Repository

    Svensson, Carsten

    2015-01-01

    Purpose The objective of this paper is to contribute to the body of Lean Six Sigma knowledge within the field of higher education institutions. The paper will review the initial phase of an implementation and highlight future challenges of applying the Lean Six Sigma method in a complex transactional environment. Design/methodology/approach The observations presented in this paper originate from rolling out a large Lean Six Sigma implementation at a recently established university. The paper is supported with secondary data from literature. Findings The implementation of Lean Six Sigma methodology at King Abdullah University of Science and Technology (KAUST) has resulted in improvements in business processes and efficiency. This has been achieved through project execution and training programs. Approximately 350 staff members have completed awareness training, 50 yellow belts and 150 green belts have been trained, and the first round of seven black belts have completed training of which two have completed certification. Research limitations/implications This paper is based on an empirical study of a single instance and the authors’ experiences as practitioners. Originality/value This paper is the first description of what is believed to be one of the largest implementations of Lean Six Sigma in higher education.

  2. Antimicrobial (Drug) Resistance: Methicillin-Resistant Staphylococcus aureus (MRSA)

    Science.gov (United States)

    ... Marketing Share this: Main Content Area Methicillin-Resistant Staphylococcus aureus (MRSA) During the past four decades, methicillin-resistant Staphylococcus aureus , or MRSA, has evolved from a controllable ...

  3. Evolution of methicillin-resistant Staphylococcus aureus towards increasing resistance

    DEFF Research Database (Denmark)

    Strommenger, Birgit; Bartels, Mette Damkjær; Kurt, Kevin;

    2014-01-01

    To elucidate the evolutionary history of Staphylococcus aureus clonal complex (CC) 8, which encompasses several globally distributed epidemic lineages, including hospital-associated methicillin-resistant S. aureus (MRSA) and the highly prevalent community-associated MRSA clone USA300....

  4. Classification of Healthcare-Associated Staphylococcus aureus Bacteremia

    DEFF Research Database (Denmark)

    Smit, Jesper; Søgaard, Mette; Schønheyder, Henrik Carl; Nielsen, Henrik; Thomsen, Reimar Wernich

    2016-01-01

    We investigated whether different definitions of healthcare-associated infection influenced the prevalence, characteristics, and mortality of patients with Staphylococcus aureus bacteremia. With different definitions, the proportion of patients classified as having healthcare-associated S. aureus...

  5. Comparative Efficacy of Ceftaroline with Linezolid against Staphylococcus Aureus and Methicillin Resistant Staphylococcus Aureus

    International Nuclear Information System (INIS)

    Objective:To compare the in vitro antimicrobial efficacy of ceftaroline with linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. Study Design: Quasi-experimental study. Place and Duration of Study: Microbiology Department, Army Medical College, Rawalpindi, from January to December 2013. Methodology: Clinical samples from respiratory tract, blood, pus and various catheter tips routinely received in the Department of Microbiology, Army Medical College, Rawalpindi were innoculated on blood and MacConkey agar. Staphylococcus aureus was identified by colony morphology, Gram reaction, catalase test and coagulase test. Methicillin resistant Staphylococcus aureus detection was done by modified Kirby Bauer disc diffusion method using cefoxitin disc (30g) and the isolates were considered methicillin resistant if the zone of inhibition around cefoxitin disc was /sup 2/ 21 mm. Bacterial suspensions of 56 Staphylococcus aureus isolates and 50 MRSA isolates were prepared, which were standardized equal to 0.5 McFarland's turbidity standard and inoculated on Mueller-Hinton agar plates followed by application of ceftaroline and linezolid disc (Oxoid, UK), according to manufacturer's instructions. The plates were then incubated at 37 Degree C aerobically for 18 - 24 hours. Diameters of inhibition zone were measured and interpretated as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of 106 isolates all of the 56 Staphylococcus aureus (100%) were sensitive to ceftaroline and linezolid. However, out of 50 methicillin resistant Staphylococcus aureus, 48 (96%) were sensitive to ceftaroline whereas, 49 (98%) were sensitive to linezolid. Conclusion: Ceftaroline is equally effective as linezolid against Staphylococcus aureus and methicillin resistant Staphylococcus aureus. (author)

  6. Characterization of a Mouse-Adapted Staphylococcus aureus Strain

    OpenAIRE

    Holtfreter, Silva; Fiona J Radcliff; Grumann, Dorothee; Read, Hannah; Johnson, Sarah; Monecke, Stefan; Ritchie, Stephen; Clow, Fiona; Goerke, Christiane; Bröker, Barbara M.; Fraser, John D.; Wiles, Siouxsie

    2013-01-01

    More effective antibiotics and a protective vaccine are desperately needed to combat the ‘superbug’ Staphylococcus aureus. While in vivo pathogenicity studies routinely involve infection of mice with human S. aureus isolates, recent genetic studies have demonstrated that S. aureus lineages are largely host-specific. The use of such animal-adapted S. aureus strains may therefore be a promising approach for developing more clinically relevant animal infection models. We have isolated a mouse-ad...

  7. Meticillin-resistant Staphylococcus aureus (MRSA)

    DEFF Research Database (Denmark)

    Stefani, Stefania; Chung, Doo Ryeon; Lindsay, Jodi A;

    2012-01-01

    This article reviews recent findings on the global epidemiology of healthcare-acquired/associated (HA), community-acquired/associated (CA) and livestock-associated (LA) meticillin-resistant Staphylococcus aureus (MRSA) and aims to reach a consensus regarding the harmonisation of typing methods...... health. Continuous efforts to understand the changing epidemiology of S. aureus infection in humans and animals are therefore necessary, not only for appropriate antimicrobial treatment and effective infection control but also to monitor the evolution of the species. The group made several consensus...

  8. A sensitive assay for Staphylococcus aureus nucleases

    International Nuclear Information System (INIS)

    A sensitive assay for staphylococcal nuclease involving incubation of the enzyme sample with heat-denatured [3H] thymidine labelled DNA from E.coli, precipitation with trichloroacetic acid and measurement of the radioactivity of acid-soluble nucleotides released has been developed. The assay is sensitive enough to be used for comparing the levels of nucleases elaborated by different strains of S. aureus as well as for determining the extent of contamination of S. aureus in food and water samples even at levels at which the conventional spectrophotometric and toluidine blue-DNA methods are totally inadequate. (author). 26 refs., 3 figs ., 3 tabs

  9. Staphylococcus aureus bacteremia in hemodialysis patients.

    Science.gov (United States)

    Latos, D L; Stone, W J; Alford, R H

    1977-01-01

    Fifteen male hemodialysis patients developed 21 episodes of S. aureus bacteremia. Infections involving vascular access were responsible for 65% of initial bacteremias. The arteriovenous fistula was the most prevalent type of access used, and thus was responsible for the majority of these illnesses. Phage typing indicated that recurrent episodes were due to reinfection rather than relapse. Complications included endocarditis, osteomyelitis, septic embolism, and pericarditis. One patient died of infectious complications. It is recommended that hemodialysis patients developing bacteremia due to S. aureus receive at least 6 weeks of beta lactamase-resistant antimicrobial therapy. PMID:608860

  10. The Staphylococcus aureus response to unsaturated long chain free fatty acids: survival mechanisms and virulence implications.

    Directory of Open Access Journals (Sweden)

    John G Kenny

    Full Text Available Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR and translational (proteomics analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the sigma(B and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM and transposon-derived mutants (vraE, SAR2632 was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered

  11. SigmaCLIPSE = presentation management + NASA CLI PS + SQL

    Science.gov (United States)

    Weiss, Bernard P., Jr.

    1990-01-01

    SigmaCLIPSE provides an expert systems and 'intelligent' data base development program for diverse systems integration environments that require support for automated reasoning and expert systems technology, presentation management, and access to 'intelligent' SQL data bases. The SigmaCLIPSE technology and and its integrated ability to access 4th generation application development and decision support tools through a portable SQL interface, comprises a sophisticated software development environment for solving knowledge engineering and expert systems development problems in information intensive commercial environments -- financial services, health care, and distributed process control -- where the expert system must be extendable -- a major architectural advantage of NASA CLIPS. SigmaCLIPSE is a research effort intended to test the viability of merging SQL data bases with expert systems technology.

  12. Analysis of CPN-1 sigma models via projective structures

    International Nuclear Information System (INIS)

    This paper represents a study of projector solutions to the Euclidean CPN-1 sigma model in two dimensions and their associated surfaces immersed in the su(N) Lie algebra. Any solution for the CPN-1 sigma model defined on the extended complex plane with finite action can be written as a raising operator acting on a holomorphic one. Here the proof is formulated in terms rank-1 projectors so it is explicitly gauge invariant. We apply these results to the analysis of surfaces associated with the CPN-1 models defined using the generalized Weierstrass formula for immersion. We show that the surfaces are conformally parametrized by the Lagrangian density, with finite area equal to the action of the model, and express several other geometrical characteristics of the surface in terms of the physical quantities of the model. Finally, we provide necessary and sufficient conditions that a surface be related to a CPN-1 sigma model

  13. Young low mass stars in the vicinity of Sigma Scorpii

    Science.gov (United States)

    Meyer, Michael R.; Wilking, Bruce A.; Zinnecker, Hans

    1993-01-01

    The region near Sigma Scorpii, a member of the Sco-Cen OB association, is examined for signs of recent star formation. Thirteen candidate young stellar objects are identified over an 80 x 80 arcmin region centered on Sigma Sco using the Point source Catalog and a recent survey for H-alpha emission-line stars. Near-infrared photometry, improved IRAS fluxes, and optical spectra are used to determine the nature of these objects. Four definite young stars are revealed, as well as one additional such object that fell just outside of the present target region. These stars, all of spectral type K or M, are argued to have formed in the vicinity of the B1 giant star Sigma Scorpii and to represent a subsample of the low-mass members of the association.

  14. Yang–Baxter sigma models based on the CYBE

    International Nuclear Information System (INIS)

    It is known that Yang–Baxter sigma models provide a systematic way to study integrable deformations of both principal chiral models and symmetric coset sigma models. In the original proposal and its subsequent development, the deformations have been characterized by classical r-matrices satisfying the modified classical Yang–Baxter equation (mCYBE). In this article, we propose the Yang–Baxter sigma models based on the classical Yang–Baxter equations (CYBE) rather than the mCYBE. This generalization enables us to utilize various kinds of solutions of the CYBE to classify integrable deformations. In particular, it is straightforward to realize partial deformations of the target space without loss of the integrability of the parent theory

  15. Sliding mode control the delta-sigma modulation approach

    CERN Document Server

    Sira-Ramírez, Hebertt

    2015-01-01

    This monograph presents a novel method of sliding mode control for switch-regulated nonlinear systems. The Delta Sigma modulation approach allows one to implement a continuous control scheme using one or multiple, independent switches, thus effectively merging the available linear and nonlinear controller design techniques with sliding mode control.   Sliding Mode Control: The Delta-Sigma Modulation Approach, combines rigorous mathematical derivation of the unique features of Sliding Mode Control and Delta-Sigma modulation with numerous illustrative examples from diverse areas of engineering. In addition, engineering case studies demonstrate the applicability of the technique and the ease with which one can implement the exposed results. This book will appeal to researchers in control engineering and can be used as graduate-level textbook for a first course on sliding mode control.

  16. Yang–Baxter sigma models based on the CYBE

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, Takuya, E-mail: takuya.matsumoto@math.nagoya-u.ac.jp [Institute for Advanced Research and Department of Mathematics, Nagoya University, Nagoya 464-8602 (Japan); Yoshida, Kentaroh, E-mail: kyoshida@gauge.scphys.kyoto-u.ac.jp [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan)

    2015-04-15

    It is known that Yang–Baxter sigma models provide a systematic way to study integrable deformations of both principal chiral models and symmetric coset sigma models. In the original proposal and its subsequent development, the deformations have been characterized by classical r-matrices satisfying the modified classical Yang–Baxter equation (mCYBE). In this article, we propose the Yang–Baxter sigma models based on the classical Yang–Baxter equations (CYBE) rather than the mCYBE. This generalization enables us to utilize various kinds of solutions of the CYBE to classify integrable deformations. In particular, it is straightforward to realize partial deformations of the target space without loss of the integrability of the parent theory.

  17. Stellar multipilicity in the {\\sigma} Orionis cluster: a review

    CERN Document Server

    Caballero, Jose A

    2014-01-01

    The nearby, young, extinction-free {\\sigma} Orionis cluster is acknowledged as a cornerstone for studying the stellar and substellar formation and evolution, especially at very low masses. However, the relatively limited knowledge of multiplicity in the cluster is dispersed among numerous papers and proceedings with very different aims and, therefore, is difficult to apprehend even for researchers in the subject. Here, I review comprehensively the sexdecuple system {\\sigma} Ori in the central arcminute, and all close (rho = 0.4-4 arcsec) and wide (rho > 4 arcsec) binaries, triples, hierarchical multiples, and spectroscopic binaries in the cluster that have been reported in the literature until 2014. I conclude with a brief enumeratation of the next steps that should be taken in the near future for having a clear picture of the multiplicity in the {\\sigma} Orionis cluster.

  18. The Process to Estimate Economical Benefits of Six Sigma Projects

    Directory of Open Access Journals (Sweden)

    Jan Kosina

    2013-07-01

    Full Text Available This paper seeks to define the process for the continuous evaluation of the financial benefits during Six Sigma project life time. The financial criteria are critical success factors of a Six Sigma project. The process has been developed as part of the six sigma project monitoring in order to estimate proper allocation of the resources taking in account the expected project benefits as well as evaluationof real achievements. The evaluation of the finacial benefits based on the quality costs is not sufficient in the real life and has to be accomplished with key financial performance indicators of the business to visualize the results. The evaluation based on the savings seems to be too difficult especially for green belts. The early involvement of the finance department in the project definition as well as ongoing evaluation is key. The defined process has been applied to real business enviroment.

  19. The Application of Six Sigma Method in a Power Plant

    Directory of Open Access Journals (Sweden)

    Zumrut Ecevit Sati

    Full Text Available In the last decade a process improvement technique, known as Six Sigma, is implemented by many pioneers of the industry as an approach used to more productive and increase profits in all business process from production to human resources management, from finance to marketing. The companies would like to keep and improve their position in a daily changing world market while new techniques and concepts are introduced to the global markets every day and this is only possible through continuous improvements and breakthroughs. In this study, it has been presented the six sigma practice of a power plant owned by Enerjisa, a major energy company in Turkey. In order to achieve Six Sigma project targets, quality techniques and statistical techniques (hypothesis testing, design of experiment etc. are used.

  20. Study of the $\\Lambda p$ Interaction Close to the $\\Sigma^+n$ and $\\Sigma^0p$ Thresholds

    CERN Document Server

    Machner, H; Hinterberger, F; Magiera, A; Niskanen, J A; Ritman, J; Siudak, R

    2013-01-01

    The $\\Lambda p$ interaction close to the $\\Sigma N$ threshold is considered. Specifically, the pronounced structure seen in production reactions like $K^-d \\to \\pi^- \\Lambda p$ and $pp\\to K^+ \\Lambda p$ around the $\\Sigma N$ threshold is analyzed. Modern interaction models of the coupled $\\Lambda N - \\Sigma N$ systems generate such a structure either due to the presence of a (deuteron-like) unstable bound state or of an inelastic virtual state. % A determination of the position of the prominent peak as observed in various experiments for the two aforementioned reactions leads to values that agree quite well with each other. Furthermore, the deduced mean value of $2128.7\\pm 0.3$ MeV for the peak position coincides practically with the threshold energy of the $\\Sigma^+ n$ channel. This supports the interpretation of the structure as a genuine cusp, signaling an inelastic virtual state in the $^3S_1-^3D_1$ partial wave of the $\\Sigma N$ isospin 1/2 channel. % There is also evidence for a second peak (or shoulder...

  1. 21 CFR 866.3700 - Staphylococcus aureus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Staphylococcus aureus serological reagents. 866... Staphylococcus aureus serological reagents. (a) Identification. Staphylococcus aureus serological reagents are... diagnosis of disease caused by this bacterium belonging to the genus Staphylococcus and...

  2. 9 CFR 113.115 - Staphylococcus Aureus Bacterin-Toxoid.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Staphylococcus Aureus Bacterin-Toxoid... REQUIREMENTS Inactivated Bacterial Products § 113.115 Staphylococcus Aureus Bacterin-Toxoid. Staphylococcus... Staphylococcus aureus which has been inactivated and is nontoxic. Each serial of biological product...

  3. A pig model of acute Staphylococcus aureus induced pyemia

    DEFF Research Database (Denmark)

    Nielsen, O. L.; Iburg, T.; Aalbæk, B.;

    2009-01-01

    Background: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus....... aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock....

  4. Multidrug-Resistant Staphylococcus aureus in US Meat and Poultry

    OpenAIRE

    Waters, Andrew E.; Contente-Cuomo, Tania; Buchhagen, Jordan; Liu, Cindy M.; Watson, Lindsey; Pearce, Kimberly; Foster, Jeffrey T.; Bowers, Jolene; Driebe, Elizabeth M; Engelthaler, David M.; Keim, Paul S; Lance B Price

    2011-01-01

    We characterized the prevalence, antibiotic susceptibility profiles, and genotypes of Staphylococcus aureus among US meat and poultry samples (n = 136). S. aureus contaminated 47% of samples, and multidrug resistance was common among isolates (52%). S. aureus genotypes and resistance profiles differed significantly among sample types, suggesting food animal–specific contamination.

  5. A Mathematical Theory of the Gauged Linear Sigma Model

    CERN Document Server

    Fan, Huijun; Ruan, Yongbin

    2015-01-01

    We construct a rigorous mathematical theory of Witten's Gauged Linear Sigma Model (GLSM). Our theory applies to a wide range of examples, including many cases with non-Abelian gauge group. Both the Gromov-Witten theory of a Calabi-Yau complete intersection X and the Landau-Ginzburg dual (FJRW-theory) of X can be expressed as gauged linear sigma models. Furthermore, the Landau-Ginzburg/Calabi-Yau correspondence can be interpreted as a variation of the moment map or a deformation of GIT in the GLSM. This paper focuses primarily on the algebraic theory, while a companion article will treat the analytic theory.

  6. The evolution of $\\sigma^{\\gamma P}$ with coherence length

    CERN Document Server

    Caldwell, Allen

    2016-01-01

    Assuming the form $\\sigma^{\\gamma P} \\propto l^{\\lambda_{\\rm eff}}$ at fixed $Q^2$ for the behavior of the virtual-photon proton scattering cross section, where $l$ is the coherence length of the photon fluctuations, it is seen that the extrapolated values of $\\sigma^{\\gamma P}$ for different $Q^2$ cross for $l\\approx 10^8$~fm. It is argued that this behavior is not physical, and that the behavior of the cross sections must change before this coherence length $l$ is reached. This could set the scale for the onset of saturation of parton densities.

  7. Barriers in green lean six sigma product development process

    DEFF Research Database (Denmark)

    Kumar, Sanjay; Luthra, Sunil; Govindan, Kannan;

    2016-01-01

    In today’s competitive globalised business environment, production cost cutting is a primary issue before operation managers. As a research area, green lean six sigma (GLS) is proposed to have strategic importance in product development towards cutting costs, contributing to optimisation, and...... achieving sustainability. This research requirement has been realised to draw benefits out of three recent and involved approaches (green, lean and six sigma). In this research, an attempt has been made to address barriers in GLS product development (GLSPD) from an extensive literature review and from...

  8. The effective action approach applied to nuclear chiral sigma model

    International Nuclear Information System (INIS)

    The nuclear chiral sigma model of nuclear matter is considered by means of the Cornwall-Jackiw-tomboulis (CTJ) effective action. The method provides a very general framework for investigating many important problems: chiral symmetry in nuclear medium, energy density of nuclear ground state, nuclear Schwinger-Dyson (SD) equations, etc. It is shown that the SD equations for sigma-omega mixing are actually not present in this formalism. For numerical computation purposes the Hartree-Fock (HF) approximation for ground state energy density is also presented. (author). 26 refs

  9. A Signal-Interleaving Complex Bandpass Sigma-Delta Converter

    DEFF Research Database (Denmark)

    Wad, Paul Emmanuel

    Complex or quadrature Sigma-Delta converters operate on complex signals, i.e. signals consisting of a real and an imaginary component, whereas conventional converters operate only on real signals. The advantage of complex signal processing in the discrete-time domain is that the entire sampling...... frequency bandwidth - not just half of it - is available, and that network zeros and poles can be placed anywhere without having to appear in complex conjugate pairs. This paper demonstrates how these properties can be used to design complex bandpass Sigma-Delta converters with a better noise performance...

  10. Double Soft Theorems and Shift Symmetry in Nonlinear Sigma Models

    CERN Document Server

    Low, Ian

    2015-01-01

    We show both the leading and subleading double soft theorems of the nonlinear sigma model follow from a shift symmetry enforcing Adler's zero condition in the presence of an unbroken global symmetry. They do not depend on the underlying coset G/H and are universal infrared behaviors of Nambu-Goldstone bosons. Although nonlinear sigma models contain an infinite number of interaction vertices, the double soft limit is determined entirely by a single four-point interaction, together with the existence of Adler's zeros.

  11. Delta-sigma modulators modeling, design and applications

    CERN Document Server

    Bourdopoulos, George I; Anastassopoulos, Vassilis; Deliyannis, Theodore L

    2003-01-01

    This important book deals with the modeling and design of higher-order single-stage delta-sigma modulators. It provides an overview of the architectures, the quantizer models, the design techniques and the implementation issues encountered in the study of the delta-sigma modulators. A number of applications are discussed, with emphasis on use in the design of analog-to-digital converters and in frequency synthesis. The book is education- rather than research-oriented, containing numerical examples and unsolved problems. It is aimed at introducing the final-year undergraduate, the graduate stud

  12. Accretion properties of T Tauri stars in sigma Ori

    OpenAIRE

    Gatti, T.; Natta, A.; Randich, S.; Testi, L.; Sacco, G.

    2008-01-01

    Accretion disks around young stars evolve in time with time scales of few million years. We present here a study of the accretion properties of a sample of 35 stars in the ~3 million year old star-forming region sigma Ori. Of these, 31 are objects with evidence of disks, based on their IR excess emission. We use near-IR hydrogen recombination lines (Pa_gamma) to measure their mass accretion rate. We find that the accretion rates are significantly lower in sigma Ori than in younger regions, su...

  13. Structural Multi-objective Probabilistic Design for Six Sigma

    Institute of Scientific and Technical Information of China (English)

    LI Yu-qiang; CUI Zhen-shan; CHEN Jun; ZHANG Dong-juan; RUAN Xue-yu

    2007-01-01

    Uncertainties in engineering design may lead to low reliable solutions that also exhibit high sensitivity to uncontrollable variations. In addition, there often exist several conflicting objectives and constraints in various design environments. In order to obtain solutions that are not only "multi-objectively" optimal, but also reliable and robust, a probabilistic optimization method was presented by integrating six sigma philosophy and multi-objective genetic algorithm. With this method, multi-objective genetic algorithm was adopted to obtain the global Pareto solutions, and six sigma method was used to improve the reliability and robustness of those optimal solutions. Two engineering design problems were provided as examples to illustrate the proposed method.

  14. Brackets, sigma models and integrability of generalized complex structures

    International Nuclear Information System (INIS)

    It is shown how derived brackets naturally arise in sigma-models via Poisson- or antibracket, generalizing a recent observation by Alekseev and Strobl. On the way to a precise formulation of this relation, an explicit coordinate expression for the derived bracket is obtained. The generalized Nijenhuis tensor of generalized complex geometry is shown to coincide up to a de-Rham closed term with the derived bracket of the structure with itself and a new coordinate expression for this tensor is presented. The insight is applied to two known two-dimensional sigma models in a background with generalized complex structure

  15. Integrable deformations of the O(3) sigma model

    International Nuclear Information System (INIS)

    We consider two one-parameter families of two-dimensional relativistic factorized scattering theories, which are deformations of the ones characteristic for the two-dimensional O(3) sigma models with θ=0 and θ=π. The Bethe ansatz technique is applied to these two families to justify their interpretation as the factorized scattering theories of certain O(2)-symmetric deformation of the O(3) sigma model (the sausage model). The result suggests that the sausage model is integrable at the topological angle values θ=0 or θ=π. (orig.)

  16. CMOS sigma-delta converters practical design guide

    CERN Document Server

    De la Rosa, Jose M

    2013-01-01

    A comprehensive overview of Sigma-Delta Analog-to-Digital Converters (ADCs) and a practical guide to their design in nano-scale CMOS for optimal performance. This book presents a systematic and comprehensive compilation of sigma-delta converter operating principles, the new advances in architectures and circuits, design methodologies and practical considerations - going from system-level specifications to silicon integration, packaging and measurements, with emphasis on nanometer CMOS implementation. The book emphasizes practical design issues - from high-level behavioural modelling i

  17. Risk factors for Staphylococcus aureus and methicillin-resistant S aureus colonization among health care workers in pediatrics departments.

    Science.gov (United States)

    Gomes, Ivete Martins; Marlow, Mariel Asbury; Pinheiro, Marcos Gabriel; de Freitas, Maria de Fátima Nogueira; Fonseca, Fernanda Fernandes; Cardoso, Claudete Aparecida Araújo; Aguiar-Alves, Fábio

    2014-08-01

    Risk factors for Staphylococcus aureus and methicillin-resistant S aureus (MRSA) were evaluated for 178 health care workers from a public hospital pediatrics department in Brazil. Colonization rates were 33.1% for S aureus and 5.1% for MRSA. Risk factors for S aureus colonization differed from those for MRSA. Results suggest nurses with prolonged pediatric patient contact in inpatient units are at higher risk for MRSA colonization. PMID:25087145

  18. Staphylococcus aureus dynamically adapts global regulators and virulence factor expression in the course from acute to chronic infection.

    Science.gov (United States)

    Tuchscherr, Lorena; Löffler, Bettina

    2016-02-01

    Staphylococcus aureus is an important pathogen of severe invasive tissue infection, e.g. osteomyelitis that can develop to chronicity and become extremely difficult to treat. Recent research revealed that S. aureus can dynamically switch to small colony variants (SCVs) that are adapted bacterial phenotypes for long-term persistence. The underlying mechanisms of the bacterial switching and adaptation process are largely dependent on an intact Sigma B regulon. As SigB is known as a transcription factor that modulates the stress response of several Gram-positive bacteria, it is most likely required by the bacteria to cope with the intracellular stress conditions. Here, we demonstrate in a long-term infection model of human osteoblasts that S. aureus continuously upregulated the expression of SigB during intracellular persistence. The increased SigB expression was accompanied by upregulation of adhesins and downregulation of toxins, which are characteristics for SCV phenotypes. These data further stress the role of SigB during chronic infections that could be a novel target for preventive or therapeutic measures to avoid chronic infections. PMID:26123224

  19. Defects in ErbB-dependent establishment of adult melanocyte stem cells reveal independent origins for embryonic and regeneration melanocytes.

    Directory of Open Access Journals (Sweden)

    Keith A Hultman

    2009-07-01

    Full Text Available Adult stem cells are responsible for maintaining and repairing tissues during the life of an organism. Tissue repair in humans, however, is limited compared to the regenerative capabilities of other vertebrates, such as the zebrafish (Danio rerio. An understanding of stem cell mechanisms, such as how they are established, their self-renewal properties, and their recruitment to produce new cells is therefore important for the application of regenerative medicine. We use larval melanocyte regeneration following treatment with the melanocytotoxic drug MoTP to investigate these mechanisms in Melanocyte Stem Cell (MSC regulation. In this paper, we show that the receptor tyrosine kinase, erbb3b, is required for establishing the adult MSC responsible for regenerating the larval melanocyte population. Both the erbb3b mutant and wild-type fish treated with the ErbB inhibitor, AG1478, develop normal embryonic melanocytes but fail to regenerate melanocytes after MoTP-induced melanocyte ablation. By administering AG1478 at different time points, we show that ErbB signaling is only required for regeneration prior to MoTP treatment and before 48 hours of development, consistent with a role in establishing MSCs. We then show that overexpression of kitla, the Kit ligand, in transgenic larvae leads to recruitment of MSCs, resulting in overproliferation of melanocytes. Furthermore, kitla overexpression can rescue AG1478-blocked regeneration, suggesting that ErbB signaling is required to promote the progression and specification of the MSC from a pre-MSC state. This study provides evidence that ErbB signaling is required for the establishment of adult MSCs during embryonic development. That this requirement is not shared with the embryonic melanocytes suggests that embryonic melanocytes develop directly, without proceeding through the ErbB-dependent MSC. Moreover, the shared requirement of larval melanocyte regeneration and metamorphic melanocytes that develops at

  20. Influenza A virus inhibits type I IFN signaling via NF-kappaB-dependent induction of SOCS-3 expression.

    Directory of Open Access Journals (Sweden)

    Eva-K Pauli

    2008-11-01

    Full Text Available The type I interferon (IFN system is a first line of defense against viral infections. Viruses have developed various mechanisms to counteract this response. So far, the interferon antagonistic activity of influenza A viruses was mainly observed on the level of IFNbeta gene induction via action of the viral non-structural protein 1 (NS1. Here we present data indicating that influenza A viruses not only suppress IFNbeta gene induction but also inhibit type I IFN signaling through a mechanism involving induction of the suppressor of cytokine signaling-3 (SOCS-3 protein. Our study was based on the observation that in cells that were infected with influenza A virus and subsequently stimulated with IFNalpha/beta, phosphorylation of the signal transducer and activator of transcription protein 1 (STAT1 was strongly reduced. This impaired STAT1 activation was not due to the action of viral proteins but rather appeared to be induced by accumulation of viral 5' triphosphate RNA in the cell. SOCS proteins are potent endogenous inhibitors of Janus kinase (JAK/STAT signaling. Closer examination revealed that SOCS-3 but not SOCS-1 mRNA levels increase in an RNA- and nuclear factor kappa B (NF-kappaB-dependent but type I IFN-independent manner early in the viral replication cycle. This direct viral induction of SOCS-3 mRNA and protein expression appears to be relevant for suppression of the antiviral response since in SOCS-3 deficient cells a sustained phosphorylation of STAT1 correlated with elevated expression of type I IFN-dependent genes. As a consequence, progeny virus titers were reduced in SOCS-3 deficient cells or in cells were SOCS-3 expression was knocked-down by siRNA. These data provide the first evidence that influenza A viruses suppress type I IFN signaling on the level of JAK/STAT activation. The inhibitory effect is at least in part due to the induction of SOCS-3 gene expression, which results in an impaired antiviral response.

  1. The light scalars and the broad $\\sigma (500)$ in the U3xU3 linear sigma model

    CERN Document Server

    Törnqvist, N A

    2000-01-01

    The lightest scalar and pseudoscalar nonets are discussed within the [A framework of the broken old UxU3 linear sigma model, and it is shown that already at the tree level this model works remarkably well predicting scalar masses and couplings not far from present experimental values, when all parameters are fixed from the pseudoscalar masses and decay constants. The linear sigma model is the simplest way to implement chiral symmetry together with the broken SU3 of the quark model, and this, not well known, success in understanding experiment is comparable to that of the naive quark model for the heavier multiplets. It is argued that this strongly suggest that the light and very broad sigma resonance exists near 500 MeV.

  2. Common R-plasmids in Staphylococcus aureus and Staphylococcus epidermidis during a nosocomial Staphylococcus aureus outbreak.

    OpenAIRE

    Cohen, M. L.; Wong, E. S.; Falkow, S

    1982-01-01

    During a 7-month period in 1978 to 1979, 31 patients and personnel at a Kentucky hospital were colonized or infected with a Staphylococcus aureus strain resistant to clindamycin, erythromycin, gentamicin, methicillin, penicillin, and tetracycline. S. epidermidis with similar antibiotic resistance patterns had been isolated in this hospital in the year before the S. aureus outbreak. A 32-megadalton R-plasmid, pUW3626, mediating resistance to penicillin and gentamicin, was present in these isol...

  3. Staphylococcus aureus resistente a la meticilina (SARM)

    Centers for Disease Control (CDC) Podcasts

    2007-10-22

    Datos importantes sobre las infecciones por SARM en Estados Unidos, en las escuelas y los entornos médicos. (Title: Methicillin-resistant Staphylococcus aureus (MRSA)Created: 10/2007).  Created: 10/22/2007 by National Center for Preparedness, Detection, and Control of Infectious Diseases.   Date Released: 11/9/2007.

  4. Staphylococcus aureus enterotoxins A- and B

    DEFF Research Database (Denmark)

    Danielsen, E Michael; Hansen, Gert H; Karlsdóttir, Edda

    2013-01-01

    Enterotoxins of Staphylococcus aureus are among the most common causes of food poisoning. Acting as superantigens they intoxicate the organism by causing a massive uncontrolled T cell activation that ultimately may lead to toxic shock and death. In contrast to our detailed knowledge regarding...

  5. Staphylococcus aureus vaccines: Deviating from the carol.

    Science.gov (United States)

    Missiakas, Dominique; Schneewind, Olaf

    2016-08-22

    Staphylococcus aureus, a commensal of the human nasopharynx and skin, also causes invasive disease, most frequently skin and soft tissue infections. Invasive disease caused by drug-resistant strains, designated MRSA (methicillin-resistant S. aureus), is associated with failure of antibiotic therapy and elevated mortality. Here we review polysaccharide-conjugate and subunit vaccines that were designed to prevent S. aureus infection in patients at risk of bacteremia or surgical wound infection but failed to reach their clinical endpoints. We also discuss vaccines with ongoing trials for combinations of polysaccharide-conjugates and subunits. S. aureus colonization and invasive disease are not associated with the development of protective immune responses, which is attributable to a large spectrum of immune evasion factors. Two evasive strategies, assembly of protective fibrin shields via coagulases and protein A-mediated B cell superantigen activity, are discussed as possible vaccine targets. Although correlates for protective immunity are not yet known, opsonophagocytic killing of staphylococci by phagocytic cells offers opportunities to establish such criteria. PMID:27526714

  6. Carriage of Staphylococcus aureus in the elderly

    NARCIS (Netherlands)

    R. M. Parnaby; G. O'Dwyer; H. A. Monsey; M. S. Shafi

    1996-01-01

    textabstractThe point prevalence and incidence of Staphylococcus aureus (methicillin-sensitive and -resistant) carriage by inpatients on acute elderly care wards was estimated. The relationship to body site and to previous admissions to hospital or other institutions was determined. Fifty-five patie

  7. Increasing resistance of Staphylococcus aureus to ciprofloxacin.

    OpenAIRE

    Daum, T E; Schaberg, D R; Terpenning, M S; Sottile, W S; Kauffman, C A

    1990-01-01

    We demonstrated the marked emergence of resistance to ciprofloxacin among Staphylococcus arueus strains isolated at the Ann Arbor Veterans Administration Medical Center. All S. aureus isolates tested from 1984 to 1985 were susceptible, whereas 55.1% of methicillin-resistant and 2.5% of methicillin-susceptible strains from 1989 had high-level resistance to ciprofloxacin.

  8. Staphylococcus aureus spa type t437

    DEFF Research Database (Denmark)

    Glasner, C; Pluister, G; Westh, H;

    2015-01-01

    large epidemiological studies in Europe. Nevertheless, the overall numbers identified in some Northern European reference laboratories have increased during the past decade. To determine whether the S. aureus t437 clone is present in other European countries, and to assess its genetic diversity across...

  9. The sigma-1 receptor enhances brain plasticity and functional recovery after experimental stroke

    DEFF Research Database (Denmark)

    Ruscher, Karsten; Shamloo, Mehrdad; Rickhag, Karl Mattias;

    2011-01-01

    )piperazine dihydrochloride, an agonist of the sigma-1 receptor, starting two days after injury, enhanced the recovery of lost sensorimotor function without decreasing infarct size. The sigma-1 receptor was found in the galactocerebroside enriched membrane microdomains of reactive astrocytes and in neurons. Sigma-1 receptor...... induced sigma-1 receptor expression and actin dependent membrane raft formation, the latter blocked by sigma-1 receptor small interfering RNA silencing and pharmacological inhibition. We conclude that sigma-1 receptor activation stimulates recovery after stroke by enhancing cellular transport...

  10. Ratio of SigmaL/SigmaT for p(e,e'K+) Lambda extracted from polarization transfer

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Carman; Brian Raue

    2005-06-01

    The ratio of longitudinal to transverse structure functions, {sigma}{sub L}/{sigma}{sub T}, has been extracted from recent beam-recoil transferred polarization data for the p({rvec e},e'K{sup +}) {rvec {Lambda}} reaction. Results have been obtained for W = 1.72, 1.84, and 1.98 GeV at an average Q{sup 2} of 0.77, 0.69, and 0.61 GeV{sup 2}, respectively. Our results indicate a ratio that is systematically slightly smaller than previously published results using a Rosenbluth separation.

  11. Gustav Naan ja Sigma Tau / Arvo Pesti, Madli Pesti

    Index Scriptorium Estoniae

    Pesti, Arvo, 1956-2010

    2009-01-01

    Füüsik, kosmoloog ja ühiskonnategelane Gustav Naanist. Merle Karusoo dokumentaallavastusest "Sigma Tau-C705", mis põhineb Enn Vetemaa ja Erki Aule näidendil "Gustav Naani hiilgus ja viletsus". Esietendus 16. märtsil 2008 Eesti Draamateatris

  12. The Moduli Space in the Gauged Linear Sigma Model

    CERN Document Server

    Fan, Huijun; Ruan, Yongbin

    2016-01-01

    This is a survey article for the mathematical theory of Witten's Gauged Linear Sigma Model, as developed recently by the authors. Instead of developing the theory in the most general setting, in this paper we focus on the description of the moduli.

  13. Polarization-induced sigma-holes and hydrogen bonding

    Czech Academy of Sciences Publication Activity Database

    Hennemann, M.; Murray, J. S.; Politzer, P.; Riley, Kevin Eugene; Clark, T.

    2012-01-01

    Roč. 18, č. 6 (2012), s. 2461-2469. ISSN 1610-2940 Institutional research plan: CEZ:AV0Z40550506 Keywords : hydrogen bond * sigma-hole * polarization * field effect * ab initio calculation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.984, year: 2012

  14. D-Dimensional Conformal $\\sigma$-models and Topological Excitations

    CERN Document Server

    Bulgadaev, S A

    2000-01-01

    The D-dimensional conformal nonlinear sigma-models (NSM) sre constructed. Itis shown that the NSM on spaces with $\\pi_{D-1} = \\mathbb {Z}$ have thetopological solutions of a "hedgehog" and "anti-hedgehog" types withlogarithmic energies. For spaces with $\\pi_D \

  15. Nucleon Properties from Approximating Chiral Quark Sigma Model

    CERN Document Server

    Abu-Shady, M

    2009-01-01

    We apply the approximating chiral quark model. This chiral quark model is based on an effective Lagrangian which the interactions between quarks via sigma and pions mesons. The field equations have been solved in the mean field approximation for the hedgehog baryon state. Good results are obtained for nucleon properties in comparison with original model.

  16. Classical solutions of a flag manifold sigma-model

    CERN Document Server

    Bykov, Dmitri

    2015-01-01

    We study a sigma-model with target space the flag manifold U(3)/U(1)^3. A peculiarity of the model is that the complex structure on the target space enters explicitly in the action. We describe the classical solutions of the model for the case when the worldsheet is a sphere CP^1.

  17. Generic Lean Six Sigma project definitions in publishing

    NARCIS (Netherlands)

    H. de Koning; R.J.M.M. Does; A. Groen; B.P.H. Kemper

    2010-01-01

    Purpose - Many companies in the publishing industry are facing the task of developing new business models and becoming more efficient and effective in execution. Lean Six Sigma (LSS) is a unified framework for systematically developing efficiency and quality improvements; it can help realize signifi

  18. ROSAT observations of the RSCVn binary sigma Geminorum

    DEFF Research Database (Denmark)

    Yi, Z.; Elgaroy, O.; Engvold, O.; Westergaard, Niels Jørgen Stenfeldt

    1997-01-01

    X-ray observations of the RSCVn system sigma Geminorum have been undertaken with the ROSAT observatory. Several spectra of very good signal-to-noise ratio were obtained. Spectral fitting using metal abundances amounting to 50% of solar values reveal two temperature components at 2 MK and 12 MK...

  19. BRST symmetries in SU(3) linear sigma model

    International Nuclear Information System (INIS)

    We study the BRST symmetries in the SU(3) linear sigma model which is constructed through the introduction of a novel matrix for the Goldstone boson fields satisfying geometrical constraints embedded in a SU(2) subgroup. To treat these constraints we exploit the improved Dirac quantization scheme. We also discuss phenomenological aspects in the mean field approach to this model. (orig.)

  20. Using Six-Sigma To Change and Measure Improvement.

    Science.gov (United States)

    Feld, Karl G.; Stone, William K.

    2002-01-01

    Explains why Honeywell's Market Research Department replaced its traditional data collection and paper-based tabulation with blended modes, including electronic interviewing and real-time reporting. Describes how the Six-Sigma quality control process demonstrated that a hybrid approach with blended modes and Web-based reporting tools could deliver…

  1. Practical Design of Delta-Sigma Multiple Description Audio Coding

    DEFF Research Database (Denmark)

    Leegaard, Jack Højholt; Østergaard, Jan; Jensen, Søren Holdt; Zamir, Ram

    2014-01-01

    It was recently shown that delta-sigma quantization (DSQ) can be used for optimal multiple description (MD) coding of Gaussian sources. The DSQ scheme combined oversampling, prediction, and noise-shaping in order to trade off side distortion for central distortion in MD coding. It was shown that...

  2. Strategically Focused Training in Six Sigma Way: A Case Study

    Science.gov (United States)

    Pandey, Ashish

    2007-01-01

    Purpose: The purpose of the current study is to examine the utility of Six Sigma interventions as a performance measure and explore its applicability for making the training design and delivery operationally efficient and strategically effective. Design/methodology/approach: This is a single revelatory case study. Data were collected from multiple…

  3. On loop contributions in the linear sigma model

    International Nuclear Information System (INIS)

    Quantum loops ares studied in the linear sigma model with scalar and pseudoscalar multiplets and a planar interaction term λTr[ΣΣ+ΣΣ+]. It is shown how quantum loops break the OZI rule and the tree-level octet-singlet degeneracy, and how the Goldstone theorem can be maintained also in an iterative scheme including some multiloop diagrams

  4. Why all this fuss over a few Sigma ?

    CERN Multimedia

    Patrice Loïez

    2001-01-01

    Sigma, the standard deviation, is the quantity used most often by physicists to express the strength of evidence for a new phenomenon. It is the way they measure the distance between the data observed and the data expected if there were no new phenomenon. What that means is best understood by taking a more familiar example : toss a fair coin (See Bulletin)

  5. Shake for Sigma, Pray for Pi: Classroom Orbital Overlap Analogies

    Science.gov (United States)

    Dicks, Andrew P.

    2011-01-01

    An introductory organic classroom demonstration is discussed where analogies are made between common societal hand contact and covalent bond formation. A handshake signifies creation of a [sigma] bond ("head-on" orbital overlap), whereas the action of praying illustrates "sideways" overlap and generation of a [pi] bond. The nature of orbital and…

  6. Nonlinearities in SC Delta-Sigma A/D Converters

    DEFF Research Database (Denmark)

    Steensgaard-Madsen, Jesper

    The effects of using nonlinear low-gain opamps in switched-capacitor delta-sigma modulators are analyzed. Using unconventional topologies, the state variables are made essentially uncorrelated with the input signal, hence opamp nonlinearity will cause very little harmonic distortion. Nonlinearity...

  7. Stability of sigma-model strings and textures

    International Nuclear Information System (INIS)

    In flat spacetime, sigma-model strings and textures are both unstable: they tend to collapse (and subsequently decay). With sufficient cosmological expansion, however, they are stable in a generalized sense: a small perturbation will cause them to change their shape, but they do not decay. The current rate of expansion is sufficient to stabilize strings, but not textures. (letter to the editor)

  8. Why is "S" a Biased Estimate of [sigma]?

    Science.gov (United States)

    Sanqui, Jose Almer T.; Arnholt, Alan T.

    2011-01-01

    This article describes a simulation activity that can be used to help students see that the estimator "S" is a biased estimator of [sigma]. The activity can be implemented using either a statistical package such as R, Minitab, or a Web applet. In the activity, the students investigate and compare the bias of "S" when sampling from different…

  9. Generic Lean Six Sigma project definitions in financial services

    NARCIS (Netherlands)

    H. de Koning; J. de Mast; R.J.M.M. Does; T. Vermaat; S. Simons

    2008-01-01

    Lean Six Sigma (LSS) is applied in financial service organizations to improve operational efficiency and effectiveness. LSS prescribes that these improvements are designed and implemented by projects. The purpose of this article is to facilitate the process of defining LSS projects in finance, becau

  10. Path integral quantization of the Poisson-Sigma model

    OpenAIRE

    Hirshfeld, Allen C.; Schwarzweller, Thomas

    1999-01-01

    We apply the antifield quantization method of Batalin and Vilkovisky to the calculation of the path integral for the Poisson-Sigma model in a general gauge. For a linear Poisson structure the model reduces to a nonabelian gauge theory, and we obtain the formula for the partition function of two-dimensional Yang-Mills theory for closed two-dimensional manifolds.

  11. SIGMA Release v1.2 - Capabilities, Enhancements and Fixes

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Vijay [Argonne National Lab. (ANL), Argonne, IL (United States); Grindeanu, Iulian R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ray, Navamita [Argonne National Lab. (ANL), Argonne, IL (United States); Jain, Rajeev [Argonne National Lab. (ANL), Argonne, IL (United States); Wu, Danqing [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-30

    In this report, we present details on SIGMA toolkit along with its component structure, capabilities, and feature additions in FY15, release cycles, and continuous integration process. These software processes along with updated documentation are imperative to successfully integrate and utilize in several applications including the SHARP coupled analysis toolkit for reactor core systems funded under the NEAMS DOE-NE program.

  12. A rational reconstruction of Six Sigma's Breakthrough Cookbook

    NARCIS (Netherlands)

    H. de Koning; J. de Mast

    2006-01-01

    Purpose: The purpose of this paper is to develop a consistent and crystallized exposition of Six-Sigma's methodology for improvement projects, which could serve as a basis for subsequent scientific research of the method. Design/methodology/approach: The paper shows that reformulation of imprecise a

  13. Non-linear sigma models with generalized geometry

    International Nuclear Information System (INIS)

    In this paper it is shown that the bosonic non-linear sigma model with algebraically extended world-sheet geometry is locally equivalent to the usual theory, but differs from the latter globally in that world-sheet instantons do not destabilize axions and in that it has a different critical dimension

  14. On the morphology of sigma-drop galaxies

    CERN Document Server

    Comerón, S; Beckman, J E

    2008-01-01

    Context: Local reductions of the stellar velocity dispersion in the central regions of galaxies are known as sigma-drops. Knowing the origin of these features can lead to better understanding of inner galactic dynamics. Aims: We present a sample of 20 sigma-drop galaxies matched with a control sample of galaxies without sigma-drop in order to search for correlations between sigma-drops and the properties, primarily morphological, of the nuclear zones and discs of their host galaxies. Methods: We study the dust and Halpha distribution at 0.1 arcsec scale, using Hubble Space Telescope imaging, in the circumnuclear zones of the two samples of galaxies, searching for differences and trying to establish a link between the nuclear kinematics and the host morphology. We have also considered the CO and HI emission of the galaxies and their luminosity profiles. Results: We classify the two samples following both morphological parameters and the luminosity profiles. We find a larger fraction of nuclear dust spirals and...

  15. Relationship between Vancomycin-Resistant Staphylococcus aureus, Vancomycin-Intermediate S. aureus, High Vancomycin MIC, and Outcome in Serious S. aureus Infections

    OpenAIRE

    Holmes, Natasha E.; Johnson, Paul D. R.; Howden, Benjamin P.

    2012-01-01

    Vancomycin has been used successfully for over 50 years for the treatment of Staphylococcus aureus infections, particularly those involving methicillin-resistant S. aureus. It has proven remarkably reliable, but its efficacy is now being questioned with the emergence of strains of S. aureus that display heteroresistance, intermediate resistance, and, occasionally, complete vancomycin resistance. More recently, an association has been established between poor outcome and infections with strain...

  16. First Measurement of sigma(gg -> ttbar)/sigma(ppbar -> ttbar)

    Energy Technology Data Exchange (ETDEWEB)

    Pashapour Alamdari, Shabnaz; /Toronto U.

    2008-06-01

    The work presented here is the first measurement of the fraction of top quark pair production through gluon-gluon fusion. We use an integrated luminosity of 0.96 {+-} 0.06 fb{sup -1} of p{bar p} collisions at {radical}s of 1.96 TeV collected by the CDF II detector. We select t{bar t} candidates by identifying a high-p{sub T} lepton candidate, a large missing E{sub T} as evidence for a neutrino candidate and at least four high E{sub T} jets, one of which has to be identified as originating from a b quark. The challenge is to discriminate between the two production processes with the identical final state, gg {yields} t{bar t} and q{bar q} {yields} t{bar t}. We take advantage of the fact that compared to a quark, a gluon is more likely to radiate a low momentum gluon and therefore, one expects a larger number of charged particles with low p{sub T} in a process involving more gluons. Given the large uncertainties associated with the modeling of the low p{sub T} charged particle multiplicity, a data-driven technique was employed. Using calibration data samples, we show there exists a clear correlation between the observed average number of low p{sub T} charged particles and the average number of gluons involved in the production process predicted by Monte Carlo calculations. Given the correlation, one can identify low p{sub T} charged particle multiplicity distributions associated with specific average number of gluons. The W + 0 jet sample and dijets sample with leading jet E{sub T} in the range of 80-100 GeV are used to find no-gluon and gluon-rich low p{sub T} charged particle multiplicity distributions, respectively. Using these no-gluon and gluon-rich distributions in a likelihood fit, we find the fraction of gluon-rich events in t{bar t} candidates. This fraction has contributions from the signal and background events. Taking into account these contributions and the gg {yields} t{bar t} and q{bar q} {yields} t{bar t} production channel acceptances, we find {sigma

  17. Study of $\\psi$ decays to the $\\Xi^{-}\\bar\\Xi^{+}$ and $\\Sigma(1385)^{\\mp}\\bar\\Sigma(1385)^{\\pm}$ final states

    CERN Document Server

    Ablikim, M; Ai, X C; Albayrak, O; Albrecht, M; Ambrose, D J; Amoroso, A; An, F F; An, Q; Bai, J Z; Ferroli, R Baldini; Ban, Y; Bennett, D W; Bennett, J V; Bertani, M; Bettoni, D; Bian, J M; Bianchi, F; Boger, E; Boyko, I; Briere, R A; Cai, H; Cai, X; Cakir, O; Calcaterra, A; Cao, G F; Cetin, S A; Chang, J F; Chelkov, G; Chen, G; Chen, H S; Chen, H Y; Chen, J C; Chen, M L; Chen, S J; Chen, X; Chen, X R; Chen, Y B; Cheng, H P; Chu, X K; Cibinetto, G; Dai, H L; Dai, J P; Dbeyssi, A; Dedovich, D; Deng, Z Y; Denig, A; Denysenko, I; Destefanis, M; De Mori, F; Ding, Y; Dong, C; Dong, J; Dong, L Y; Dong, M Y; Dou, Z L; Du, S X; Duan, P F; Fan, J Z; Fang, J; Fang, S S; Fang, X; Fang, Y; Farinelli, R; Fava, L; Fedorov, O; Feldbauer, F; Felici, G; Feng, C Q; Fioravanti, E; Fritsch, M; Fu, C D; Gao, Q; Gao, X L; Gao, X Y; Gao, Y; Gao, Z; Garzia, I; Goetzen, K; Gong, L; Gong, W X; Gradl, W; Greco, M; Gu, M H; Gu, Y T; Guan, Y H; Guo, A Q; Guo, L B; Guo, Y; Guo, Y P; Haddadi, Z; Hafner, A; Han, S; Hao, X Q; Harris, F A; He, K L; Held, T; Heng, Y K; Hou, Z L; Hu, C; Hu, H M; Hu, J F; Hu, T; Hu, Y; Huang, G S; Huang, J S; Huang, X T; Huang, Y; Hussain, T; Ji, Q; Ji, Q P; Ji, X B; Ji, X L; Jiang, L W; Jiang, X S; Jiang, X Y; Jiao, J B; Jiao, Z; Jin, D P; Jin, S; Johansson, T; Julin, A; Kalantar-Nayestanaki, N; Kang, X L; Kang, X S; Kavatsyuk, M; Ke, B C; Kiese, P; Kliemt, R; Kloss, B; Kolcu, O B; Kopf, B; Kornicer, M; Kupsc, A; Kühn, W; Lange, J S; Lara, M; Larin, P; Leng, C; Li, C; Li, Cheng; Li, D M; Li, F; Li, F Y; Li, G; Li, H B; Li, J C; Li, Jin; Li, K; Li, Lei; Li, P R; Li, Q Y; Li, T; Li, W D; Li, W G; Li, X L; Li, X N; Li, X Q; Li, Z B; Liang, H; Liang, Y F; Liang, Y T; Liao, G R; Lin, D X; Liu, B J; Liu, C X; Liu, D; Liu, F H; Liu, Fang; Liu, Feng; Liu, H B; Liu, H H; Liu, H M; Liu, J; Liu, J B; Liu, J P; Liu, J Y; Liu, K; Liu, K Y; Liu, L D; Liu, P L; Liu, Q; Liu, S B; Liu, X; Liu, Y B; Liu, Z A; Liu, Zhiqing; Loehner, H; Lou, X C; Lu, H J; Lu, J G; Lu, Y; Lu, Y P; Luo, C L; Luo, M X; Luo, T; Luo, X L; Lyu, X R; Ma, F C; Ma, H L; Ma, L L; Ma, Q M; Ma, T; Ma, X N; Ma, X Y; Ma, Y M; Maas, F E; Maggiora, M; Mao, Y J; Mao, Z P; Marcello, S; Messchendorp, J G; Min, J; Mitchell, R E; Mo, X H; Mo, Y J; Morales, C; Muchnoi, N Yu; Muramatsu, H; Nefedov, Y; Nerling, F; Nikolaev, I B; Ning, Z; Nisar, S; Niu, S L; Niu, X Y; Olsen, S L; Ouyang, Q; Pacetti, S; Pan, Y; Patteri, P; Pelizaeus, M; Peng, H P; Peters, K; Pettersson, J; Ping, J L; Ping, R G; Poling, R; Prasad, V; Qi, H R; Qi, M; Qian, S; Qiao, C F; Qin, L Q; Qin, N; Qin, X S; Qin, Z H; Qiu, J F; Rashid, K H; Redmer, C F; Ripka, M; Rong, G; Rosner, Ch; Ruan, X D; Santoro, V; Sarantsev, A; Savrié, M; Schoenning, K; Schumann, S; Shan, W; Shao, M; Shen, C P; Shen, P X; Shen, X Y; Sheng, H Y; Song, W M; Song, X Y; Sosio, S; Spataro, S; Sun, G X; Sun, J F; Sun, S S; Sun, Y J; Sun, Y Z; Sun, Z J; Sun, Z T; Tang, C J; Tang, X; Tapan, I; Thorndike, E H; Tiemens, M; Ullrich, M; Uman, I; Varner, G S; Wang, B; Wang, B L; Wang, D; Wang, D Y; Wang, K; Wang, L L; Wang, L S; Wang, M; Wang, P; Wang, P L; Wang, S G; Wang, W; Wang, W P; Wang, X F; Wang, Y D; Wang, Y F; Wang, Y Q; Wang, Z; Wang, Z G; Wang, Z H; Wang, Z Y; Weber, T; Wei, D H; Wei, J B; Weidenkaff, P; Wen, S P; Wiedner, U; Wolke, M; Wu, L H; Wu, Z; Xia, L; Xia, L G; Xia, Y; Xiao, D; Xiao, H; Xiao, Z J; Xie, Y G; Xiu, Q L; Xu, G F; Xu, L; Xu, Q J; Xu, Q N; Xu, X P; Yan, L; Yan, W B; Yan, W C; Yan, Y H; Yang, H J; Yang, H X; Yang, L; Yang, Y X; Ye, M; Ye, M H; Yin, J H; Yu, B X; Yu, C X; Yu, J S; Yuan, C Z; Yuan, W L; Yuan, Y; Yuncu, A; Zafar, A A; Zallo, A; Zeng, Y; Zeng, Z; Zhang, B X; Zhang, B Y; Zhang, C; Zhang, C C; Zhang, D H; Zhang, H H; Zhang, H Y; Zhang, J J; Zhang, J L; Zhang, J Q; Zhang, J W; Zhang, J Y; Zhang, J Z; Zhang, K; Zhang, L; Zhang, X Y; Zhang, Y; Zhang, Y H; Zhang, Y N; Zhang, Y T; Zhang, Yu; Zhang, Z H; Zhang, Z P; Zhang, Z Y; Zhao, G; Zhao, J W; Zhao, J Y; Zhao, J Z; Zhao, Lei; Zhao, Ling; Zhao, M G; Zhao, Q; Zhao, Q W; Zhao, S J; Zhao, T C; Zhao, Y B; Zhao, Z G; Zhemchugov, A; Zheng, B; Zheng, J P; Zheng, W J; Zheng, Y H; Zhong, B; Zhou, L; Zhou, X; Zhou, X K; Zhou, X R; Zhou, X Y; Zhu, K; Zhu, K J; Zhu, S; Zhu, S H; Zhu, X L; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, J; Zotti, L; Zou, B S; Zou, J H

    2016-01-01

    We study the decays of the charmonium resonances $J/\\psi$ and $\\psi(3686)$ to the final states $\\Xi^{-}\\bar\\Xi^{+}$, $\\Sigma(1385)^{\\mp}\\bar\\Sigma(1385)^{\\pm}$ based on a single baryon tag method using data samples of $(223.7 \\pm 1.4) \\times 10^{6}$ $J/\\psi$ and $(106.4 \\pm 0.9) \\times 10^{6}$ $\\psi(3686)$ events collected with the BESIII detector at the BEPCII collider. The decay $\\psi(3686)\\rightarrow\\Sigma(1385)^{\\mp}\\bar\\Sigma(1385)^{\\pm}$ is observed for the first time, and the measurements of the other processes, including the branching fractions and angular distributions, are in good agreement with and much more precise than the previously published results. Additionally, the ratios $\\frac{{\\cal{B}}(\\psi(3686)\\rightarrow\\Xi^{-}\\bar\\Xi^{+})}{{\\cal{B}}(J/\\psi\\rightarrow\\Xi^{-}\\bar\\Xi^{+})}$, $\\frac{{\\cal{B}}(\\psi(3686)\\rightarrow\\Sigma(1385)^{-}\\bar\\Sigma(1385)^{+})}{{\\cal{B}}(J/\\psi\\rightarrow\\Sigma(1385)^{-}\\bar\\Sigma(1385)^{+})}$ and $\\frac{{\\cal{B}}(\\psi(3686)\\rightarrow\\Sigma(1385)^{+}\\bar\\Sigma(138...

  18. Staphylococcus aureus methicillin-resistance mechanisms

    Directory of Open Access Journals (Sweden)

    Petrović-Jeremić Ljiljana

    2008-01-01

    Full Text Available Background/Aim. In many hospitals in the world and in our country, the spread of methicillin-resistant Staphylococcus aureus (MRSA is so wide that nowdays vancomycin is recommended for empiric treatment of staphylococcal life threatening infections (sepsis, pneumonia instead of beta-lactam antibiotics. The aim of this study was to determine the production of beta-lactamases in hospital and community isolates of staphyloococus aureus, i. e. hospital associated MRSA (HA-MRSA and community associated MRSA (CA-MRSA, the presence of homogeneous and heterogeneous type of methicillin resistance, and border-line resistance in Staphylococcus aureus (BORSA. The aim of this study was also to determine if there was a statistically significant difference between mechanisms of resistance in HA-MRSA and CA-MRSA. Methods. A total 216 clinical Staphylococcus aureus isolates from the General Hospital in the town of Cuprija and 186 ambulance Staphylococcus aureus isolates from the community were examined for the presence of methicillin-resistance using disk-diffusion test with penicillin disk (10 ij, oxacillin disk (1 μg and cefoxitin disk (30 μg. Betalactamases production was detected by nitrocefin disk and betalactamase tablets. Determination of oxacillin minimum inhibitory concentracion (MIC was done by agar-dilution method. Results. The prevalence of HA-MRSA was 57.4%, and CA-MRSA was 17.7% (p < 0.05. There was a higher rate of heterogeneous type of resistance among clinical MRSA isolates (11.1% compared with ambulance ones (3.8% (p < 0.05. The rates of beta-lactamases production were similar among hospital associated isolates (97.5%, as well as in the community associated isolates (95.5% (p > 0.05. There were 4.6 % of BORSA hospital isolates and 3.3 % of BORSA ambulance isolates (p > 0.05. Conclusion. The frequency of MRSA isolates in hospital was significantly higher than in community, as well as the heterogeneous type of resistance. The frequency of BORSA

  19. Exploring the potential of sigma factors for strain development in Corynebacterium glutamicum

    OpenAIRE

    Taniguchi, Hironori

    2016-01-01

    A sigma factor is one of the components of RNA polymerase holoenzyme and responsible for promoter recognition and transcription initiation. Bacteria usually possess multiple genes encoding sigma factors and strictly control their activity. Activation of a specific sigma factor alters the promoter recognition of the RNA polymerase holoenzyme and enhances the transcription of a specific set of genes with similar promoter sequences. Therefore, sigma factors can be used for activating expression ...

  20. Single and Double Peripheral Production of Sigmas in Proton Proton Collisions

    OpenAIRE

    Kisslinger, Leonard S.; Ma, Wei-hsing; Shen, Pengnian

    2004-01-01

    The Pomeron, which dominates high energy elastic and diffractive hadronic processes, must be largely gluonic in nature. We use a recent picture of a scalar glueball/sigma system with coupling of the sigma to glue determined from experiment to predict strong peripheral sigma production in the pp$\\pi^0\\pi^0$ and double sigma production in the pp$\\pi^0\\pi^0\\pi^0\\pi^0$ channels.

  1. The sigma factor sigma s affects antibiotic production and biological control activity of Pseudomonas fluorescens Pf-5.

    Science.gov (United States)

    Sarniguet, A; Kraus, J; Henkels, M D; Muehlchen, A M; Loper, J E

    1995-12-19

    Pseudomonas fluorescens Pf-5, a rhizosphere-inhabiting bacterium that suppresses several soilborne pathogens of plants, produces the antibiotics pyrrolnitrin, pyoluteorin, and 2,4-diacetylphloroglucinol. A gene necessary for pyrrolnitrin production by Pf-5 was identified as rpoS, which encodes the stationary-phase sigma factor sigma s. Several pleiotropic effects of an rpoS mutation in Escherichia coli also were observed in an RpoS- mutant of Pf-5. These included sensitivities of stationary-phase cells to stresses imposed by hydrogen peroxide or high salt concentration. A plasmid containing the cloned wild-type rpoS gene restored pyrrolnitrin production and stress tolerance to the RpoS- mutant of Pf-5. The RpoS- mutant overproduced pyoluteorin and 2,4-diacetyl-phloroglucinol, two antibiotics that inhibit growth of the phytopathogenic fungus Pythium ultimum, and was superior to the wild type in suppression of seedling damping-off of cucumber caused by Pythium ultimum. When inoculated onto cucumber seed at high cell densities, the RpoS- mutant did not survive as well as the wild-type strain on surfaces of developing seedlings. Other stationary-phase-specific phenotypes of Pf-5, such as the production of cyanide and extracellular protease(s) were expressed by the RpoS- mutant, suggesting that sigma s is only one of the sigma factors required for the transcription of genes in stationary-phase cells of P. fluorescens. These results indicate that a sigma factor encoded by rpoS influences antibiotic production, biological control activity, and survival of P. fluorescens on plant surfaces. PMID:8618880

  2. Six Sigma: not for the faint of heart.

    Science.gov (United States)

    Benedetto, Anthony R

    2003-01-01

    Six Sigma is an excellent quality and performance improvement tool. Like any tool, the results of using it are highly dependent on whether you use it with competence and on the right problem. This article will help you decide if your problem is well-suited for a Six Sigma approach and will suggest the optimum approach for planning and implementing Six Sigma methodology. Performance improvement methods can be grouped into two broad categories, based on the problem to be addressed. When the problem is relatively minor and localized, "evolutionary" methods may be suitable (e.g., quality circles, problem-solving staff meetings, continuous quality improvement [CQI], total quality management [TQM]). These tools work best when modest incremental improvements are sought, when major process redesign is not thought to be necessary, and when the avoidance of workplace disruption is desired. Reengineering and Six Sigma are the best-known examples of the "revolutionary" performance improvement methods. These methods should be used when major (drastic, do or die, etc.) improvements are needed. Problems that cross departmental boundaries need these methods. When a process is so dysfunctional that you feel like you need to tear up the standard operating procedure (SOP) and start all over again, you need a revolutionary method. A Six Sigma project requires a major expenditure of money and employee time, and a willingness to make some hard decisions about jobs, employee retention and relationships among stakeholders. An institution's culture should be considered as part of the decision about using Six Sigma. If the institution has a history of making data-driven decisions, or at least has displayed openness to operating in that manner, Six Sigma has a good chance of success. A radiology-driven Six Sigma project should not be undertaken until a comprehensive written description of the scope of the project is approved by the radiology department leadership team and by the appropriate

  3. Analysis of Haptoglobin and Hemoglobin-Haptoglobin Interactions with the Neisseria meningitidis TonB-Dependent Receptor HpuAB by Flow Cytometry

    OpenAIRE

    Rohde, Kyle H.; Dyer, David W.

    2004-01-01

    Neisseria meningitidis expresses a two-component TonB-dependent receptor, HpuAB, which mediates heme-iron (Hm-Fe) acquisition from hemoglobin and hemoglobin-haptoglobin complexes. Due to genetic polymorphisms in the human haptoglobin gene, haptoglobin (and hemoglobin-haptoglobin) exists as three structurally distinct phenotypes. In this study, we examined the influence of the haptoglobin phenotype on the interactions of HpuAB with apo-haptoglobin and hemoglobin-haptoglobin. Growth assays conf...

  4. 77 FR 31390 - Manufacturer of Controlled Substances; Notice of Registration; Sigma Aldrich Research...

    Science.gov (United States)

    2012-05-25

    ... February 6, 2012, 77 FR 5847, Sigma Aldrich Research Biochemicals, Inc., 1-3 Strathmore Road, Natick... Enforcement Administration Manufacturer of Controlled Substances; Notice of Registration; Sigma Aldrich....C. 823(a) and determined that the registration of Sigma Aldrich Research Biochemicals, Inc....

  5. 77 FR 1491 - Sigma Corporation; Analysis of Proposed Consent Order To Aid Public Comment

    Science.gov (United States)

    2012-01-10

    ... Sigma Corporation; Analysis of Proposed Consent Order To Aid Public Comment AGENCY: Federal Trade... SUPPLEMENTARY INFORMATION section below. Write ``Sigma, File No. 101 0080'' on your comment, and file your... receive it on or before February 6, 2012. Write ``Sigma, File No. 101 0080'' on your comment. Your...

  6. 78 FR 64020 - Manufacturer of Controlled Substances; Notice of Registration; Sigma Aldrich Research...

    Science.gov (United States)

    2013-10-25

    ..., 2013, 78 FR 33442, Sigma Aldrich Research Biochemicals, Inc., 1-3 Strathmore Road, Natick... Enforcement Administration Manufacturer of Controlled Substances; Notice of Registration; Sigma Aldrich... in 21 U.S.C. 823(a), and determined that the registration of Sigma Aldrich Research Biochemicals,...

  7. 78 FR 37605 - Sigma Investment Advisors, LLC, et al.; Notice of Application

    Science.gov (United States)

    2013-06-21

    ... COMMISSION Sigma Investment Advisors, LLC, et al.; Notice of Application June 14, 2013. AGENCY: Securities... outside of the same group of investment companies as the series to acquire Shares. Applicants: Sigma Shares Exchange-Traded Fund Trust (``Trust''), Sigma Investment Advisors, LLC (``Initial Adviser''),...

  8. A Framework for Six Sigma Project Selection in Higher Educational Institutions, Using a Weighted Scorecard Approach

    Science.gov (United States)

    Holmes, Monica C.; Jenicke, Lawrence O.; Hempel, Jessica L.

    2015-01-01

    Purpose: This paper discusses the importance of the Six Sigma selection process, describes a Six Sigma project in a higher educational institution and presents a weighted scorecard approach for project selection. Design/Methodology/Approach: A case study of the Six Sigma approach being used to improve student support at a university computer help…

  9. Methicillin-resistant Staphylococcus aureus: the superbug.

    Science.gov (United States)

    Ippolito, Giuseppe; Leone, Sebastiano; Lauria, Francesco N; Nicastri, Emanuele; Wenzel, Richard P

    2010-10-01

    Over the last decade, methicillin-resistant Staphylococcus aureus (MRSA) strains have emerged as serious pathogens in the nosocomial and community setting. Hospitalization costs associated with MRSA infections are substantially greater than those associated with methicillin-sensitive S. aureus (MSSA) infections, and MRSA has wider economic effects that involve indirect costs to the patient and to society. In addition, there is some evidence suggesting that MRSA infections increase morbidity and the risk of mortality. Glycopeptides are the backbone antibiotics for the treatment of MRSA infections. However, several recent reports have highlighted the limitations of vancomycin, and its role in the management of serious infections is now being reconsidered. Several new antimicrobials demonstrate in vitro activity against MRSA and other Gram-positive bacteria. Data from large surveys indicate that linezolid, daptomycin, and tigecycline are almost universally active against MRSA. This review will briefly discuss the epidemiology, costs, outcome, and therapeutic options for the management of MRSA infections. PMID:20851011

  10. Curcumin Reverse Methicillin Resistance in Staphylococcus aureus

    OpenAIRE

    Su-Hyun Mun; Sung-Bae Kim; Ryong Kong; Jang-Gi Choi; Youn-Chul Kim; Dong-Won Shin; Ok-Hwa Kang; Dong-Yeul Kwon

    2014-01-01

    Curcumin, a natural polyphenolic flavonoid extracted from the rhizome of Curcuma longa L., was shown to possess superior potency to resensitize methicillin-resistant Staphylococcus aureus (MRSA) to antibiotics. Previous studies have shown the synergistic activity of curcumin with β-lactam and quinolone antibiotics. Further, to understand the anti-MRSA mechanism of curcumin, we investigated the potentiated effect of curcumin by its interaction in diverse conditions. The mechanism of anti-MRSA ...

  11. Xanthgranulomatous pyelonephritis associated with Staphylococcus aureus.

    Science.gov (United States)

    Al-Hwiesh, Abdulla K

    2007-11-01

    A 44-year old man with xanthogranulomatous pyelonephritis presented with abdominal distention, left lumber pain, fever, loss of appetite, and loss of weight. He had been known to have diabetes mellitus type II for 20 years, and he was diagnosed to have a left renal stone three months prior to this presentation. The patient's urine and the left psous abscess grew staphylococcus aureus. PMID:17951953

  12. Xanthgranulomatous pyelonephritis associated with staphylococcus aureus

    International Nuclear Information System (INIS)

    A 44-year-old man with xanthgranulomatous pyelonephritis presented with abdominal distention, left lumber pain, fever, loss of appetite and loss of weight. He had been known to have diabetes mellitus type II for 20 years and he was diagnosed to have a left renal stone three months prior to this presentation. The patient's urine and the left psous abscess grew staphylococcus aureus. (author)

  13. Sigma-1 Receptor Imaging in the Brain: Cerebral sigma-1 receptors and cognition: Small-animal PET studies using 11C-SA4503

    OpenAIRE

    Kuzhuppilly Ramakrishnan, Nisha

    2014-01-01

    The sigma-1 receptor is a unique orphan receptor, strongly expressed in neurons and glia. Sigma-1 receptors are involved in several central nervous system (CNS) disorders like depression, anxiety, psychosis, schizophrenia, Parkinson’s disease, Alzheimer’s disease, addiction and neuropathic pain. Several CNS drugs like haloperidol, donepezil, rimcazole, fluvoxamine, sertraline and clorgyline have moderate to high sigma-1 receptor affinity. Pharmaceutical companies currently involved in R&D and...

  14. Aspartate inhibits Staphylococcus aureus biofilm formation.

    Science.gov (United States)

    Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

    2015-04-01

    Biofilm formation renders Staphylococcus aureus highly resistant to conventional antibiotics and host defenses. Four D-amino acids (D-Leu, D-Met, D-Trp and D-Tyr) have been reported to be able to inhibit biofilm formation and disassemble established S. aureus biofilms. We report here for the first time that both D- and L-isoforms of aspartate (Asp) inhibited S. aureus biofilm formation on tissue culture plates. Similar biofilm inhibition effects were also observed against other staphylococcal strains, including S. saprophyticus, S. equorum, S. chromogenes and S. haemolyticus. It was found that Asp at high concentrations (>10 mM) inhibited the growth of planktonic N315 cells, but at subinhibitory concentrations decreased the cellular metabolic activity without influencing cell growth. The decreased cellular metabolic activity might be the reason for the production of less protein and DNA in the matrix of the biofilms formed in the presence of Asp. However, varied inhibition efficacies of Asp were observed for biofilms formed by clinical staphylococcal isolates. There might be mechanisms other than decreasing the metabolic activity, e.g. the biofilm phenotypes, affecting biofilm formation in the presence of Asp. PMID:25687923

  15. Whole-Genome Sequence of Staphylococcus aureus Strain LCT-SA112

    OpenAIRE

    Wang, Junfeng; Liu, Yanhong; Wan, Daiwei; Fang, Xiangqun; Li, Tianzhi; Guo, Yinghua; Chang, De; Su, Longxiang; Wang, Yajuan; Zhao, Jiao; Liu, Changting

    2012-01-01

    Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. S. aureus is the most common species of Staphylococcus to cause staphylococcal infections, which are very common in clinical medicine. Here we report the genome sequence of S. aureus strain LCT-SA112, which was isolated from S. aureus subsp. aureus CGMCC 1.230.

  16. Transition probabilities of the B-prime 1Sigma(u)(+) to X 1Sigma(g)(+) system of molecular hydrogen

    Science.gov (United States)

    Kwok, T. L.; Dalgarno, A.; Posen, A.

    1985-01-01

    From published potential energy curves and transition dipole moments, there are obtained by numerical integration of the equations of nuclear motion the vibrational eigenfunctions of the X 1Sigma(g)(+) and B-prime 1Sigma(u)(+) states of H2. The probabilities of radiative transitions from the discrete vibrational levels of the excited B-prime 1Sigma(u)(+) electronic state of H2 to the discrete and continuum vibrational levels of the ground X 1Sigma(g)(+) electronic state are calculated. The Franck-Condon factors are also presented.

  17. Six sigma for organizational excellence a statistical approach

    CERN Document Server

    Muralidharan, K

    2015-01-01

    This book discusses the integrated concepts of statistical quality engineering and management tools. It will help readers to understand and apply the concepts of quality through project management and technical analysis, using statistical methods. Prepared in a ready-to-use form, the text will equip practitioners to implement the Six Sigma principles in projects. The concepts discussed are all critically assessed and explained, allowing them to be practically applied in managerial decision-making, and in each chapter, the objectives and connections to the rest of the work are clearly illustrated. To aid in understanding, the book includes a wealth of tables, graphs, descriptions and checklists, as well as charts and plots, worked-out examples and exercises. Perhaps the most unique feature of the book is its approach, using statistical tools, to explain the science behind Six Sigma project management and integrated in engineering concepts. The material on quality engineering and statistical management tools of...

  18. Sigma-1 Receptor Modulates Neuroinflammation After Traumatic Brain Injury.

    Science.gov (United States)

    Dong, Hui; Ma, Yunfu; Ren, Zengxi; Xu, Bin; Zhang, Yunhe; Chen, Jing; Yang, Bo

    2016-07-01

    Traumatic brain injury (TBI) remains a significant clinical problem and contributes to one-third of all injury-related deaths. Activated microglia-mediated inflammatory response is a distinct characteristic underlying pathophysiology of TBI. Here, we evaluated the effect and possible mechanisms of the selective Sigma-1 receptor agonist 2-(4-morpholinethyl)-1-phenylcyclohexanecarboxylate (PRE-084) in mice TBI model. A single intraperitoneal injection 10 μg/g PRE-084, given 15 min after TBI significantly reduced lesion volume, lessened brain edema, attenuated modified neurological severity score, increased the latency time in wire hang test, and accelerated body weight recovery. Moreover, immunohistochemical analysis with Iba1 staining showed that PRE-084 lessened microglia activation. Meanwhile, PRE-084 reduced nitrosative and oxidative stress to proteins. Thus, Sigma-1 receptors play a major role in inflammatory response after TBI and may serve as useful target for TBI treatment in the future. PMID:26228028

  19. Hadron Properties in a Chiral Quark-Sigma Model

    CERN Document Server

    Rashdan, M; El-Kholy, S; Abu-Shady, M

    2011-01-01

    Within a chiral quark sigma model in which quarks interact via the exchange of sigma and pi-mesons, hadron properties are investigated. This model of the nucleon and delta is based on the idea that strong QCD forces on very short distances (a small length scales 0.2- 1 fm) result in hidden chiral SU(2)xSU(2) symmetry and that there is a separation of roles between these forces which are responsible for binding quarks in hadrons and the forces which produce absolute confinement. We have solved the field equations in the mean field approximation for the hedgehog baryon state with different sets of model parameters. A new parametrization which well describe the nucleon properties has been introduced and compared with experimental data.

  20. Off-shell BCJ Relation in Nonlinear Sigma Model

    CERN Document Server

    Chen, Gang; Liu, Hanqing

    2016-01-01

    We investigate relations among tree-level off-shell currents in nonlinear sigma model. Under Cayley parametrization, we propose and prove a general revised BCJ relation for even-point currents. Unlike the on-shell BCJ relation, the off-shell one behaves quite differently from Yang-Mills theory although the algebraic structure is the same. After performing the permutation summation in the revised BCJ relation, the sum is non-vanishing, instead, it equals to the sum of sub-current products with the BCJ coefficients under a specific ordering, which is presented by an explicit formula. Taking on-shell limit, this identity is reduced to the on-shell BCJ relation, and thus provides the full off-shell correspondence of tree-level BCJ relation in nonlinear sigma model.

  1. Nonlinear Sigma Models with Compact Hyperbolic Target Spaces

    CERN Document Server

    Gubser, Steven; Schoenholz, Samuel S; Stoica, Bogdan; Stokes, James

    2015-01-01

    We explore the phase structure of nonlinear sigma models with target spaces corresponding to compact quotients of hyperbolic space, focusing on the case of a hyperbolic genus-2 Riemann surface. The continuum theory of these models can be approximated by a lattice spin system which we simulate using Monte Carlo methods. The target space possesses interesting geometric and topological properties which are reflected in novel features of the sigma model. In particular, we observe a topological phase transition at a critical temperature, above which vortices proliferate, reminiscent of the Kosterlitz-Thouless phase transition in the $O(2)$ model. Unlike in the $O(2)$ case, there are many different types of vortices, suggesting a possible analogy to the Hagedorn treatment of statistical mechanics of a proliferating number of hadron species. Below the critical temperature the spins cluster around six special points in the target space known as Weierstrass points. The diversity of compact hyperbolic manifolds suggest...

  2. Lepton Private Higgs and the discrete group \\Sigma(81)

    CERN Document Server

    BenTov, Yoni

    2012-01-01

    We use the discrete group \\Sigma(81) = (Z_3 x Z_3 x Z_3)\\rx Z_3 to suggest a relation among the off-diagonal entries of the neutrino mass matrix, as well as to explain the muon magnetic moment anomaly, a_\\mu^exp-a_\\mu^SM ~ 10^{-9}. We predict three new nearly degenerate Higgs doublets with masses of order ~500 GeV to ~ 1 TeV, and three nearly degenerate SM-singlet TeV-scale neutrinos. The largest scale in the model is ~10 TeV, so there is no severe hierarchy problem. The appendix is devoted to the group theory of \\Sigma(81).

  3. Aplikace lean six sigma v racionalizaci technologické linky

    OpenAIRE

    Petráš, Jaroslav

    2008-01-01

    Předkládaná práce se zabývá metodami konceptu lean six sigma, které se vztahují k problematice zefektivňování průmyslových procesů. Část práce je věnována postupu řešení optimalizace pomocí modelu DMAIC a propojení se six sigma a TOC. Hlavní pozornost je zaměřena na použití modelu DMAIC při vyhodnocování na data z technologické linky Cobalt firmy Motorola.

  4. Applying a Hybrid MCDM Model for Six Sigma Project Selection

    Directory of Open Access Journals (Sweden)

    Fu-Kwun Wang

    2014-01-01

    Full Text Available Six Sigma is a project-driven methodology; the projects that provide the maximum financial benefits and other impacts to the organization must be prioritized. Project selection (PS is a type of multiple criteria decision making (MCDM problem. In this study, we present a hybrid MCDM model combining the decision-making trial and evaluation laboratory (DEMATEL technique, analytic network process (ANP, and the VIKOR method to evaluate and improve Six Sigma projects for reducing performance gaps in each criterion and dimension. We consider the film printing industry of Taiwan as an empirical case. The results show that our study not only can use the best project selection, but can also be used to analyze the gaps between existing performance values and aspiration levels for improving the gaps in each dimension and criterion based on the influential network relation map.

  5. DEPLOYMENT OF SIX SIGMA METHODOLOGY IN PHACOEMULSIFICATION CATARACT SURGERY

    Directory of Open Access Journals (Sweden)

    Ibrahim SAHBAZ

    2014-04-01

    Full Text Available The purpose of this study is to show how a public eye care center in Turkey initiated Six Sigma principles to reduce the number of complications encountered during and after phacoemulsification cataract surgeries. To analyze the 3-year data, main tools of Six Sigma’s Define-Measure-Analyze-Improve-Control (DMAIC improvement cycle such as SIPOC table, Fishbone Diagram and, Failure, Mode and Effect Analysis were implemented. Experience of the ophthalmic surgeon, patient’s anatomy, cooperation of patient during the surgery, sterilization and hygiene, attention of assistant surgeon, calibration of equipment and quality/chemical composition of intraocular material were identified to be Critical-to-Quality (CTQ factors for a successful phacoemulsification cataract surgery. The most frequently occurring complication was found to be iris atrophy. The process sigma level for the process was found to be 3.958.

  6. IMPROVE MACHINING PROCESS CAPABILITY BY USING SIX-SIGMA

    Directory of Open Access Journals (Sweden)

    Sanjit Ray

    2011-06-01

    Full Text Available Abstract: Six-Sigma is an improvement strategy for achieving customer satisfaction by reducing variation and thus producing products and services better, faster and cheaper. This study presents a Six-Sigma project of an automotive plant illustrating how the DMAIC methodology and statistical techniques were applied to resolve the issue of manufacturing process capability. This project has substantially benefit ted the organization by reducing the variation of bore size of crank case, achieving zero rejection and improving the on time delivery. By using appropriate qualitative and quantitative tools in different phases of the DMAIC methodology, the critical output, key process inputs and root causes were identified, analyzed and validated. This project methodology can be used in general to reduce process variation for any other manufacturing processes as well, which will help in improving customer satisfaction.

  7. New observations with the gamma ray imager SIGMA

    Science.gov (United States)

    Roques, J. P.; Vedrenne, G.

    1992-01-01

    Results from the use of the gamma ray telescope SIGMA are given. An identification and an extensive study was done of sources contributing to the emission of the Galactic center region above 30 keV. A strong line was observed at 480 keV from Nova Muscae, which may be interpreted as an annihilation line with a redshift due to the presence of a compact object. The soft x-ray tails observed by SIGMA in some transient sources already identified as soft x-ray transients might be a common characteristic of these objects and has to be explained. The unusual spectrum of NGC4151 with a break around 50 keV can characterize a particular state of this kind of object. If it is the case, it has interesting implications for the origin of the Cosmic Diffuse Background.

  8. N=2 sigma models for Ramond-Ramond backgrounds

    International Nuclear Information System (INIS)

    Using the U(4) hybrid formalism, manifestly N=(2,2) worldsheet supersymmetric sigma models are constructed for the type-IIB superstring in Ramond-Ramond backgrounds. The Kahler potential in these N=2 sigma models depends on four chiral and antichiral bosonic superfields and two chiral and antichiral fermionic superfields. When the Kahler potential is quadratic, the model is a free conformal field theory which describes a flat ten-dimensional target space with Ramond-Ramond flux and non-constant dilaton. For more general Kahler potentials, the model describes curved target spaces with Ramond-Ramond flux that are not plane-wave backgrounds. Ricci-flatness of the Kahler metric implies the on-shell conditions for the background up to the usual four-loop conformal anomaly. (author)

  9. Effective action and vacuum expectations in nonlinear $\\sigma$ model

    CERN Document Server

    Fayzullaev, B A

    2015-01-01

    The equations for effective action for nonlinear $\\sigma$ model are derived using DeWitt method in two forms - for generator of vertex parts $\\Gamma$ and for generator of weakly connected parts $W$. Loop-expansion solutions to these equations are found. It is shown that vacuum expectation values for various quantities including divergence of a N\\"{o}ther current, trace of the energy-momentum tensor and so on, can be calculated by this method. Also it is shown that vacuum expectation to the sigma-field is determined by an explicit combination of tree Green function and classical solution. It is shown that the limit when coupling constant tends to zero is singular one.

  10. Optimization of steel bar manufacturing process using six sigma

    Science.gov (United States)

    Naeem, Khawar; Ullah, Misbah; Tariq, Adnan; Maqsood, Shahid; Akhtar, Rehman; Nawaz, Rashid; Hussain, Iftikhar

    2016-03-01

    Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and controlmethodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar(Khyber Pakhtunkhwa, Pakistan). The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

  11. Digital Pixel Sensor Array with Logarithmic Delta-Sigma Architecture

    Directory of Open Access Journals (Sweden)

    Jing Li

    2013-08-01

    Full Text Available Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs. To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia.

  12. Digital pixel sensor array with logarithmic delta-sigma architecture.

    Science.gov (United States)

    Mahmoodi, Alireza; Li, Jing; Joseph, Dileepan

    2013-01-01

    Like the human eye, logarithmic image sensors achieve wide dynamic range easily at video rates, but, unlike the human eye, they suffer from low peak signal-to-noise-and-distortion ratios (PSNDRs). To improve the PSNDR, we propose integrating a delta-sigma analog-to-digital converter (ADC) in each pixel. An image sensor employing this architecture is designed, built and tested in 0.18 micron complementary metal-oxide-semiconductor (CMOS) technology. It achieves a PSNDR better than state-of-the-art logarithmic sensors and comparable to the human eye. As the approach concerns an array of many ADCs, we use a small-area low-power delta-sigma design. For scalability, each pixel has its own decimator. The prototype is compared to a variety of other image sensors, linear and nonlinear, from industry and academia. PMID:23959239

  13. Sigma-model soliton intersections from exceptional calibrations

    CERN Document Server

    Portugues, R

    2002-01-01

    A first-order `BPS' equation is obtained for 1/8 supersymmetric intersections of soliton-membranes (lumps) of supersymmetric (4+1)-dimensional massless sigma models, and a special non-singular solution is found that preserves 1/4 supersymmetry. For 4-dimensional hyper-K\\"ahler target spaces ($HK_4$) the BPS equation is shown to be the low-energy limit of the equation for a Cayley-calibrated 4-surface in $\\bE^4\\times HK_4$. Similar first-order equations are found for stationary intersections of Q-lump-membranes of the massive sigma model, but now generic solutions preserve either 1/8 supersymmetry or no supersymmetry, depending on the time orientation.

  14. D-brane Solitons in Supersymmetric Sigma-Models

    CERN Document Server

    Gauntlett, J P; Tong, D; Townsend, P K; Gauntlett, Jerome P.; Portugues, Rubén; Tong, David; Townsend, Paul K.

    2001-01-01

    Massive D=4 N=2 supersymmetric sigma models typically admit domain wall (Q-kink) solutions and string (Q-lump) solutions, both preserving 1/2 supersymmetry. We exhibit a new static 1/4 supersymmetric `kink-lump' solution in which a string ends on a wall, and show that it has an effective realization as a BIon of the D=4 super DBI-action. It is also shown to have a time-dependent Q-kink-lump generalization which reduces to the Q-lump in a limit corresponding to infinite BI magnetic field. All these 1/4 supersymmetric sigma-model solitons are shown to be realized in M-theory as calibrated, or `Q-calibrated', M5-branes in an M-monopole background.

  15. Sigma, Kappa, fo(980) and a0(980)

    CERN Document Server

    Bugg, D V

    2005-01-01

    Both sigma and kappa are well established from E791 data on D->3pi and Ds->Kpipi and BES II data on J/Psi -> omega pi pi and KKpipi. These fits are accurately consistent with pipi and Kpi elastic scattering when one allows for the Adler zero which arises from Chiral Symmetry Breaking. The phase variation with mass is consistent between elastic scattering and production data. Possible interpretations of sigma, kappa, fo(980) and ao(980) are explored. The experimental ratio g^2(fo(980)->KK)/g^2(ao(980)->KK) = 2.7+-0.5 suggests strongly that fo(980) has a large KK component in its wave function. This is a natural consequence of its pole lying very close to the KK threshold.

  16. DEVELOPMENT OF SIX SIGMA INFRASTRUCTURE FOR STRABISMUS SURGERIES

    Directory of Open Access Journals (Sweden)

    Mehmet Tolga Taner

    2014-01-01

    Full Text Available The purpose of this study is to show how a private eye care center in Turkey developed a Six Sigma infrastructure to investigate the root causes of complications occuring during strabismus surgeries. To analyze the collected data, main tools of Six Sigma’s Define-Measure-Analyze-Improve-Control (DMAIC improvement cycle such as SIPOC table, Fishbone Diagram and, Failure, Mode and Effect Analysis were implemented. Patient’s eye anatomy, experience of the anesthesiologist, experience/attention of the strabismus surgeon was identified to be Critical-to-Quality (CTQ factors for a successful strabismus surgery. The most frequent complications of strabismus surgeries were found to be X, Y and Z. The process sigma level was found to be 3.2025.

  17. Optimization of Steel Bar Manufacturing Process Using Six Sigma

    Institute of Scientific and Technical Information of China (English)

    NAEEM Khawar; ULLAH Misbah; TARIQ Adnan; MAQSOOD Shahid; AKHTAR Rehman; NAWAZ Rashid; HUSSAIN Iftikhar

    2016-01-01

    Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and control- methodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar(Khyber Pakhtunkhwa, Pakistan). The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

  18. Multi-Agent Modeling in Managing Six Sigma Projects

    Directory of Open Access Journals (Sweden)

    K. Y. Chau

    2009-10-01

    Full Text Available In this paper, a multi-agent model is proposed for considering the human resources factor in decision making in relation to the six sigma project. The proposed multi-agent system is expected to increase the acccuracy of project prioritization and to stabilize the human resources service level. A simulation of the proposed multiagent model is conducted. The results show that a multi-agent model which takes into consideration human resources when making decisions about project selection and project team formation is important in enabling efficient and effective project management. The multi-agent modeling approach provides an alternative approach for improving communication and the autonomy of six sigma projects in business organizations.

  19. Rethinking behavioral health processes by using design for six sigma.

    Science.gov (United States)

    Lucas, Anthony G; Primus, Kelly; Kovach, Jamison V; Fredendall, Lawrence D

    2015-02-01

    Clinical evidence-based practices are strongly encouraged and commonly utilized in the behavioral health community. However, evidence-based practices that are related to quality improvement processes, such as Design for Six Sigma, are often not used in behavioral health care. This column describes the unique partnership formed between a behavioral health care provider in the greater Pittsburgh area, a nonprofit oversight and monitoring agency for behavioral health services, and academic researchers. The authors detail how the partnership used the multistep process outlined in Design for Six Sigma to completely redesign the provider's intake process. Implementation of the redesigned process increased access to care, decreased bad debt and uncollected funds, and improved cash flow--while consumer satisfaction remained high. PMID:25642607

  20. Is health care ready for Six Sigma quality?

    Science.gov (United States)

    Chassin, M R

    1998-01-01

    Serious, widespread problems exist in the quality of U.S. health care: too many patients are exposed to the risks of unnecessary services; opportunities to use effective care are missed; and preventable errors lead to injuries. Advanced practitioners of industrial quality management, like Motorola and General Electric, have committed themselves to reducing the frequency of defects in their business processes to fewer than 3.4 per million, a strategy known as Six Sigma Quality. In health care, quality problems frequently occur at rates of 20 to 50 percent, or 200,000 to 500,000 per million. In order to approach Six Sigma levels of quality, the health care sector must address the underlying causes of error and make important changes: adopting new educational models; devising strategies to increase consumer awareness; and encouraging public and private investment in quality improvement. PMID:9879303

  1. Look-ahead based sigma-delta modulation

    CERN Document Server

    Janssen, Erwin

    2011-01-01

    The aim of this book is to expand and improve upon the existing knowledge on discrete-time 1-bit look-ahead sigma-delta modulation in general, and to come to a solution for the above mentioned specific issues arising from 1-bit sigma-delta modulation for SA-CD. In order to achieve this objective an analysis is made of the possibilities for improving the performance of digital noise-shaping look-ahead solutions. On the basis of the insights obtained from the analysis, several novel generic 1-bit look-ahead solutions that improve upon the state-of-the-art will be derived and their performance wi

  2. Contribuições do Seis Sigma: estudos de caso em multinacionais Contributions from Six Sigma: case studies in multinationals

    Directory of Open Access Journals (Sweden)

    Adriana Barbosa Santos

    2010-03-01

    Full Text Available A literatura sugere que o Seis Sigma trouxe contribuições sob vários aspectos, tanto no âmbito da gestão da qualidade como também da gestão estratégica. No entanto, ainda há certa escassez de informações sobre esse assunto no cenário organizacional brasileiro. Este artigo visa reduzir essa carência da literatura, mostrando uma visão prática sobre as contribuições decorrentes dos investimentos no Seis Sigma para empresas do Brasil. A relevância de requisitos essenciais - como conceito de qualidade; combinação das abordagens estatística e estratégica; sistematização metodológica; formação de especialistas; e gestão de projetos - é discutida tanto em âmbito teórico-conceitual como prático. O método do estudo de caso foi aplicado para obter o embasamento empírico da pesquisa. Os investimentos no Seis Sigma feitos por duas subsidiárias brasileiras de empresas multinacionais norte-americanas (uma de manufatura e uma de serviços são apresentados e reforçam a relevância dos requisitos supracitados.The literature suggests that Six Sigma has made many contributions to quality and strategic management. However, there is a certain lack of information about this subject in the Brazilian organizational scene. This paper aims to reduce this lack by means of a practical vision of the contributions that came from the investment of Brazilian companies in Six Sigma implementation. The relevance of essentials requirements, such as: quality concept; combination of statistical and strategic approaches; methodological systemizing; belt training; and project management is discussed from both the theoretical and practical aspects. Case study method was applied to obtain an empirical basis for the research. The investment in Six Sigma undertaken by two Brazilian branches of large multinationals (one a Manufacturing Company and the other a Service Company are described and analyzed, underlining the relevance of these requirements.

  3. [Raw milk-associated Staphylococcus aureus intoxication in children].

    Science.gov (United States)

    Giezendanner, N; Meyer, B; Gort, M; Müller, P; Zweifel, C

    2009-07-01

    Four hours after the consumption of raw goat milk, three Swiss children came down with emesis and diarrhea in July 2008. First investigations showed that the milk originated from a goat suffering from clinical mastitis (Staphylococcus aureus). In the milk sample from the untreated left udder, Staphylococcus aureus counts reached 5.0 x 10(7) CFU ml(-1). By PCR, the gene for the staphylococcal enterotoxin D was found in isolated strains. The consumption of raw milk is rarely associated with Staphylococcus aureus intoxications. Due to the flora naturally present in raw milk, Staphylococcus aureus normally cannot multiply sufficiently. However, in the present case, high Staphylococcus aureus counts were already present in the milk due to the mastitis of the goat. This amount sufficed to cause a Staphylococcus aureus intoxication in the children. PMID:19565455

  4. Six Sigma: Problems, Limitations, Critical Success Factors and Future Prospects

    OpenAIRE

    Paulo Mazieiro Pohlmann; Marco Antônio Ferreira

    2015-01-01

    Six Sigma is a business strategy based on objective decision making and problem solving in order to achieve, maintain and maximize business success through understanding and meeting the needs of customers. The visualization of this methodology as a powerful tool in reducing variability and improving quality led to the interest in performing this bibliographical study, whose purpose was to assess the critical success factors and future prospects of this managerial system. A survey ...

  5. Power efficient Delta Sigma bitstream encoder/decoder

    OpenAIRE

    2009-01-01

    The thesis presents design and implementation of components for recoding of signals between binary PCM and a bitstream representation. The bitstream representation enables real time signal processing using a power efficient algorithm for time-domain cross-correlation. The greatest savings are made when the system is restricted to a low oversampling ratio (OSR). A fully digital Delta Sigma encoder is presented. The low OSR is the largest limiting factor in the system. Both simulations and ...

  6. On the large $N$ expansion in hyperbolic sigma-models

    CERN Document Server

    Niedermaier, Max

    2007-01-01

    Invariant correlation functions for ${\\rm SO}(1,N)$ hyperbolic sigma-models are investigated. The existence of a large $N$ asymptotic expansion is proven on finite lattices of dimension $d \\geq 2$. The unique saddle point configuration is characterized by a negative gap vanishing at least like 1/V with the volume. Technical difficulties compared to the compact case are bypassed using horospherical coordinates and the matrix-tree theorem.

  7. Stability of sinusoidal responses of interpolative sigma delta modulators

    OpenAIRE

    Ho, Charlotte Yuk-Fan; Ling, Bingo Wing-Kuen

    2007-01-01

    In this paper, stability of sinusoidal responses of interpolative sigma delta modulators (SDMs) is investigated. It is found that interpolative SDMs may switch from unstable to stable behaviors even though the magnitude or the frequency of the input sinusoidal signals increase. Hence, the input magnitude stability margin and the input frequency stability margin are redefined as the minimum input magnitude and the minimum input frequency of the input sinusoidal signals such that the output of ...

  8. Auxiliary field formulation of supersymmetric nonlinear sigma models

    International Nuclear Information System (INIS)

    Two dimensional N=2 supersymmetric nonlinear sigma models on hermitian symmetric spaces are formulated in terms of the auxiliary superfields. If we eliminate auxiliary vector and chiral superfields, they give D- and F- term constraints to define the target manifolds. The integration over auxiliary vector superfields, which can be performed exactly, is equivalent to the elimination of the auxiliary fields by the use of the classical equations of motion. (author)

  9. Existence of $\\sigma$ meson in $\\pi-\\pi$ scattering

    CERN Document Server

    Harada, M

    1997-01-01

    In this talk I summarize a recently proposed mechanism to understand pi pi scattering to 1 GeV. The model is motivated by the 1/Nc expansion to QCD, and includes a current algebra contact term and resonant pole exchanges. Chiral symmetry plays an important role in restricting the form of the interactions. The existence of a broad low energy scalar (sigma) is indicated.

  10. Roles of sigma-1 receptors in Alzheimer’s disease

    OpenAIRE

    Jin, Jia-li; Fang, Min; Zhao, Yan-Xin; Liu, Xue-Yuan

    2015-01-01

    Alzheimer’s disease (AD) is a progressive neurodegenerative disorder and the leading cause of senile dementia all over the world. Still no existing drugs can effectively reverse the cognitive impairment. However, Sigma-1 (σ-1) receptors have been long implicated in multiple neurological and psychiatric conditions over these years. In this review, we discuss the current understanding of σ-1 receptor functions. Through regulation of lipid rafts, secretases, kinases, neuroceptors and ion channel...

  11. The Nonlinear Sigma Model With Distributed Adaptive Mesh Refinement

    OpenAIRE

    Liebling, Steven L.

    2004-01-01

    An adaptive mesh refinement (AMR) scheme is implemented in a distributed environment using Message Passing Interface (MPI) to find solutions to the nonlinear sigma model. Previous work studied behavior similar to black hole critical phenomena at the threshold for singularity formation in this flat space model. This work is a follow-up describing extensions to distribute the grid hierarchy and presenting tests showing the correctness of the model.

  12. Cigarette Reject Rate Reduction using a Lean Six Sigma Approach

    OpenAIRE

    Berty, Esteban

    2011-01-01

    Due to changes in customer demands, companies often need to improve their processes and approach them in different ways. Waste elimination is very important for every company in their quest to reduce costs and use resources efficiently. Variation reduction helps keep processes steady and more accurate. Two powerful tools for process improvement are Lean and Six Sigma, when combined can bring many benefits to organizations that decide to implement them. The amount of continuous improvement too...

  13. Linear $\\sigma$ model for the Goldstone Higgs - Experimental tests

    CERN Document Server

    Saa, Sara

    2016-01-01

    In order to explore a possible dynamical nature for the Higgs field (such as its being a pseudo-Goldstone boson) we develop a renormalizable Lagrangian based on the minimal $SO(5)$ linear $\\sigma$-model with the symmetry softly broken to $SO(4)$, including gauge bosons and fermions. We then present the phenomenological implications and constraints from precision observables and the impact on present and future LHC data.

  14. Exploring the Six Sigma phenomenon using multiple case study evidence

    OpenAIRE

    Nonthaleerak, P; Hendry, L

    2008-01-01

    Purpose – This research paper aims to: explore areas of weakness in six sigma implementations that may require enhancements in the methodology; to investigate implementation differences between manufacturing and services; and to investigate critical success factors. Design/methodology/approach – Exploratory empirical evidence is presented from nine case study companies in Thailand, including manufacturers, sales and service companies and a national airline. Findings – Key findings include: si...

  15. Is Health Care Ready for Six Sigma Quality?

    OpenAIRE

    Chassin, Mark R.

    1998-01-01

    Serious, widespread problems exist in the quality of U.S. health care: too many patients are exposed to the risks of unnecessary services; opportunities to use effective care are missed; and preventable errors lead to injuries. Advanced practitioners of industrial quality management, like Motorola and General Electric, have committed themselves to reducing the frequency of defects in their business processes to fewer than 3.4 per million, a strategy known as Six Sigma Quality. In health care,...

  16. Implementation of Design for Six Sigma on Mass Customization Companies

    OpenAIRE

    Jurado Lara, Laura

    2012-01-01

    The role of quality control is to correctly translate customers´ requirements into materialized products to achieve customers’ satisfaction. Today Product Development Process (PDP) becomes the stage to improve and to obtain successful products. In the 1980s, Six Sigma appeared as an attempt to improve some aspects of products and services in order to reduce failures in production as much as possible. But there still was a lack of customer perspective over product development project. This the...

  17. Geometry of surfaces associated to Grassmannian sigma models

    Science.gov (United States)

    Delisle, L.; Hussin, V.; Zakrzewski, W. J.

    2015-04-01

    We investigate the geometric characteristics of constant Gaussian curvature surfaces obtained from solutions of the G(m, n) sigma model. Most of these solutions are related to the Veronese sequence. We show that we can distinguish surfaces with the same Gaussian curvature using additional quantities like the topological charge and the mean curvature. The cases of G(1,n) = CPn-1 and G(2,n) are used to illustrate these characteristics.

  18. Geometry of surfaces associated to grassmannian sigma models

    OpenAIRE

    Delisle, Laurent; Hussin, Véronique; Zakrzewski, Wojtek J.

    2014-01-01

    We investigate the geometric characteristics of constant gaussian curvature surfaces obtained from solutions of the $G(m,n)$ sigma model. Most of these solutions are related to the Veronese sequence. We show that we can distinguish surfaces with the same gaussian curvature using additional quantities like the topological charge and the mean curvature. The cases of $G(1,n)=\\mathbb{C}P^{n-1}$ and $G(2,n)$ are used to illustrate these characteristics.

  19. Pion- and strangeness-baryon $\\sigma$ terms in the extended chiral constituent quark model

    OpenAIRE

    An, C. S.; Saghai, B.

    2014-01-01

    Within an extended chiral constituent quark formalism, we investigate contributions from all possible five-quark components in the octet baryons to the pion-baryon ($\\sigma_{\\pi B}$) and strangeness-baryon ($\\sigma_{s B}$) sigma terms; $B \\equiv N,~\\Lambda,~\\Sigma,~\\Xi$. The probabilities of the quark-antiquark components in the ground-state baryon octet wave functions are calculated by taking the baryons to be admixtures of three- and five-quark components, with the relevant transitions hand...

  20. Statistical and Managerial Techniques for Six Sigma Methodology Theory and Application

    CERN Document Server

    Barone, Stefano

    2012-01-01

    Statistical and Managerial Techniques for Six Sigma Methodology examines the methodology through illustrating the most widespread tool and techniques involved in Six Sigma application. Both managerial and statistical aspects of Six Sigma will be analyzed, allowing the reader to apply these tools in the field. This book offers an insight on variation and risk management, and focuses on the structure and organizational aspects of the Six Sigma projects. It covers six sigma methodology, basic managerial techniques, basic statistical techniques, methods for variation and risk management and advanc

  1. Note on a sigma model connection with instanton dynamics

    International Nuclear Information System (INIS)

    It is well known that the instanton approach to QCD generates an effective term which looks like a three-flavor determinant of quark bilinears. This has the right behavior to explain the unusual mass and mixing of the η(958) meson, as is often simply illustrated with the aid of a linear SU(3) sigma model. It is less well known that the instanton analysis generates another term which has the same transformation property but does not have a simple interpretation in terms of this usual linear sigma model. Here we point out that this term has an interpretation in a generalized linear sigma model containing two chiral nonets. The second chiral nonet is taken to correspond to mesons having two quarks and two antiquarks in their makeup. The generalized model seems to be useful for learning about the spectrum of low-lying scalar mesons which have been emerging in the last few years. The physics of the new term is shown to be related to the properties of an excited η' state present in the generalized model and for which there are some experimental candidates.

  2. Note on a sigma model connection with instanton dynamics

    CERN Document Server

    Fariborz, Amir H; Schechter, Joseph

    2008-01-01

    It is well known that the instanton approach to QCD generates an effective term which looks like a three flavor determinant of quark bilinears. This has the right behavior to explain the unusual mass and mixing of the $\\eta(958)$ meson, as is often simply illustrated wih the aid of a linear SU(3) sigma model. It is less well known that the instanton analysis generates another term which has the same transformation property but does not have a simple interpretation in terms of this usual linear sigma model. Here we point out that this term has an interpretation in a generalized linear sigma model containing two chiral nonets. The second chiral nonet is taken to correspond to mesons having two quarks and two antiquarks in their makeup. The generalized model seems to be useful for learning about the spectrum of low lying scalar mesons which have been emerging in the last few years. The physics of the new term is shown to be related to the properties of an "excited" $\\eta'$ state present in the generalized model ...

  3. Tree-level Amplitudes in the Nonlinear Sigma Model

    CERN Document Server

    Kampf, Karol; Trnka, Jaroslav

    2013-01-01

    We study in detail the general structure and further properties of the tree-level amplitudes in the SU(N) nonlinear sigma model. We construct the flavor-ordered Feynman rules for various parameterizations of the SU(N) fields U(x), write down the Berends-Giele relations for the semi-on-shell currents and discuss their efficiency for the amplitude calculation in comparison with those of renormalizable theories. We also present an explicit form of the partial amplitudes up to ten external particles. It is well known that the standard BCFW recursive relations cannot be used for reconstruction of the the on-shell amplitudes of effective theories like the SU(N) nonlinear sigma model because of the inappropriate behavior of the deformed on-shell amplitudes at infinity. We discuss possible generalization of the BCFW approach introducing "BCFW formula with subtractions" and with help of Berends-Giele relations we prove particular scaling properties of the semi-on-shell amplitudes of the SU(N) nonlinear sigma model und...

  4. Tree-level amplitudes in the nonlinear sigma model

    Science.gov (United States)

    Kampf, Karol; Novotný, Jirí; Trnka, Jaroslav

    2013-05-01

    We study in detail the general structure and further properties of the tree-level amplitudes in the SU( N) nonlinear sigma model. We construct the flavor-ordered Feynman rules for various parameterizations of the SU( N) fields U ( x), write down the Berends-Giele relations for the semi-on-shell currents and discuss their efficiency for the amplitude calculation in comparison with those of renormalizable theories. We also present an explicit form of the partial amplitudes up to ten external particles. It is well known that the standard BCFW recursive relations cannot be used for reconstruction of the the on-shell amplitudes of effective theories like the SU( N) nonlinear sigma model because of the inappropriate behavior of the deformed on-shell amplitudes at infinity. We discuss possible generalization of the BCFW approach introducing "BCFW formula with subtractions" and with help of Berends-Giele relations we prove particular scaling properties of the semi-on-shell amplitudes of the SU( N) nonlinear sigma model under specific shifts of the external momenta. These results allow us to define alternative deformation of the semi-on-shell amplitudes and derive BCFW-like recursion relations. These provide a systematic and effective tool for calculation of Goldstone bosons scattering amplitudes and it also shows the possible applicability of on-shell methods to effective field theories. We also use these BCFW-like relations for the investigation of the Adler zeroes and double soft limit of the semi-on-shell amplitudes.

  5. How can one understand the lightest scalars, especially the $\\sigma$

    CERN Document Server

    Törnqvist, N A

    2001-01-01

    We discuss how the a_0(980), f_0(980), K^*_0(1430) and particularly the broad sigma resonance can be understood within a coupled channel framework, which includes all light two-pseudoscalar thresholds together with constraints from Adler zeroes, flavour symmetric couplings, unitarity and physically acceptable analyticity. All (qbar q) scalars are, when unitarized, strongly distorted by hadronic mass shifts, and the nonstrange isoscalar state becomes a very broad resonance, with its pole at 470-i250 MeV. We believe this is the sigma meson required by models for spontaneous breaking of chiral symmetry. Recently this light resonance has clearly been observed in D-> sigma pi-> 3pi by the E791 experiment at Fermilab, and we discuss how this decay channel can be predicted in a Constituent Quark Meson Model (CQM), which incorporates heavy quark and chiral symmetries. We also discuss the less well known phenomenon that with a large coupling there can appear two physical resonance poles on the second sheet although on...

  6. Sigma factors in a thousand E. coli genomes

    DEFF Research Database (Denmark)

    Cook, Helen Victoria; Ussery, David

    2013-01-01

    , we describe a method to quickly sort through genomes for a particular set of protein families. We apply these two methods to all of the current Escherichia coli genomes available in the The National Center for Biotechnology Information database. Out of the 2074 E. coli/Shigella genomes listed (June......, 2013), only less than half (983) are of sufficient quality to use in comparative genomic work. Unfortunately, even some of the ‘complete’ E. coli genomes are in pieces, and a few ‘draft’ genomes are good quality. Six of the seven known sigma factors in E. coli strain K‐12 are extremely well conserved......; the iron‐regulating sigma factor FecI (σ19) is missing in most genomes. Surprisingly, the E. coli strain CFT073 genome does not encode a functional RpoD (σ70), which is obviously essential, and this is likely due to poor genome assembly/annotation. We find a possible novel sigma factor present in more...

  7. Antibody responses in patients with invasive Staphylococcus aureus infections

    OpenAIRE

    Jacobsson, G; Colque-Navarro, P.; Gustafsson, E.; Andersson, R.; Möllby, R

    2010-01-01

    Abstract Correlation between antibody response and clinical outcome in Staphylococcus aureus bacteremia has yielded conflicting results. Immunization schedules have failed in clinical trials. Is the humoral response toward S. aureus of protective nature? A prospective study was performed in patients with invasive S. aureus (ISA) infections during the period 2003?2005. The antibody levels were determined at the beginning and at the end of treatment and one month later (n?=?96, n?=?7...

  8. Vitamin D sufficiency and Staphylococcus aureus infection in children.

    Science.gov (United States)

    Wang, Jeffrey W; Hogan, Patrick G; Hunstad, David A; Fritz, Stephanie A

    2015-05-01

    Vitamin D promotes epithelial immunity by upregulating antimicrobial peptides, including LL-37, which have bactericidal activity against Staphylococcus aureus. We found that children with vitamin D deficiency or insufficiency [25-hydroxyvitamin D recurrent, rather than primary, S. aureus skin or soft tissue infection. Vitamin D sufficiency may be one of a myriad of host and environmental factors that can be directly impacted to reduce the frequency of S. aureus skin and soft tissue infection. PMID:25860535

  9. Mapping the Distribution of Invasive Staphylococcus aureus across Europe

    OpenAIRE

    Grundmann, Hajo; Aanensen, David M.; van den Wijngaard, Cees C.; Brian G Spratt; Harmsen, Dag; Friedrich, Alexander W.; ,

    2010-01-01

    Editors' Summary Background The bacterium Staphylococcus aureus lives on the skin and in the nose of about a third of healthy people. Although S. aureus usually coexists peacefully with its human carriers, it is also an important disease-causing organism or pathogen. If it enters the body through a cut or during a surgical procedure, S. aureus can cause minor infections such as pimples and boils or more serious, life-threatening infections such as blood poisoning and pneumonia. Minor S. aureu...

  10. Infection control of Staphylococcus aureus : spa typing to elucidate transmission

    OpenAIRE

    Mernelius, Sara

    2015-01-01

    Staphylococcus aureus is a commensal of the human flora, primarily colonizing the anterior nares and throat, but it may also cause infections ranging from mild skin and soft tissue infections to severe diseases such as endocarditis and septicemia. S. aureus is also a major nosocomial problem increasing with the worldwide dissemination of methicillin-resistant S. aureus (MRSA). The main vector for bacterial cross-transmission in healthcare settings is the hands of healthcare workers (HCWs). No...

  11. Staphylococcus aureus atsparumas antibiotikams ir fagotipų paplitimas

    OpenAIRE

    Kareivienė, Violeta; Pavilonis, Alvydas; Sinkutė, Gintarė; Liegiūtė, Sigutė; Gailienė, Greta

    2006-01-01

    Objective. The aim of this study was to identify the phage groups of Staphylococcus aureus strains, their prevalence, and resistance of different phage groups to antibiotics. Materials and methods. A total of 294 Staphylococcus aureus strains in Kaunas hospitals were obtained; they were phage typed and their resistance to antibiotics was determined. We used the method of routine dilution to test 17 antibiotics against the isolates. Susceptibility of Staphylococcus aureus to studied antibio...

  12. Threat of drug resistant Staphylococcus aureus to health in Nepal

    OpenAIRE

    Ansari, Shamshul; Nepal, Hari Prasad; Gautam, Rajendra; Rayamajhi, Nabin; Shrestha, Sony; Upadhyay, Goma; Acharya, Anju; Chapagain, Moti Lal

    2014-01-01

    Background Staphylococcus aureus is the most commonly isolated organism from the different clinical samples in hospital. The emergence and dissemination of methicillin resistant Staphylococcus aureus (MRSA) and growing resistance to non-beta-lactam antibiotics is making treatment of infections due to this organism increasingly difficult. Methods This study was conducted to determine the frequency of Staphylococcus aureus isolated from different clinical samples, rates of MRSA and full antibio...

  13. Epicutaneous Model of Community-Acquired Staphylococcus aureus Skin Infections

    OpenAIRE

    Prabhakara, Ranjani; Foreman, Oded; De Pascalis, Roberto; Lee, Gloria M.; Plaut, Roger D.; Kim, Stanley Y.; Stibitz, Scott; Elkins, Karen L.; Merkel, Tod J.

    2013-01-01

    Staphylococcus aureus is one of the most common etiological agents of community-acquired skin and soft tissue infection (SSTI). Although the majority of S. aureus community-acquired SSTIs are uncomplicated and self-clearing in nature, some percentage of these cases progress into life-threatening invasive infections. Current animal models of S. aureus SSTI suffer from two drawbacks: these models are a better representation of hospital-acquired SSTI than community-acquired SSTI, and they involv...

  14. Comparative Analysis of the σB-Dependent Stress Responses in Listeria monocytogenes and Listeria innocua Strains Exposed to Selected Stress Conditions▿ †

    OpenAIRE

    Raengpradub, Sarita; Wiedmann, Martin; Boor, Kathryn J.

    2007-01-01

    The alternative sigma factor σB contributes to transcription of stress response and virulence genes in diverse gram-positive bacterial species. The composition and functions of the Listeria monocytogenes and Listeria innocua σB regulons were hypothesized to differ due to virulence differences between these closely related species. Transcript levels in stationary-phase cells and in cells exposed to salt stress were characterized by microarray analyses for both species. In L. monocytogenes, 168...

  15. Contribuições do Seis Sigma: estudos de caso em multinacionais Contributions from Six Sigma: case studies in multinationals

    OpenAIRE

    Adriana Barbosa Santos; Manoel Fernando Martins

    2010-01-01

    A literatura sugere que o Seis Sigma trouxe contribuições sob vários aspectos, tanto no âmbito da gestão da qualidade como também da gestão estratégica. No entanto, ainda há certa escassez de informações sobre esse assunto no cenário organizacional brasileiro. Este artigo visa reduzir essa carência da literatura, mostrando uma visão prática sobre as contribuições decorrentes dos investimentos no Seis Sigma para empresas do Brasil. A relevância de requisitos essenciais - como conceito de quali...

  16. The hallucinogen N,N-dimethyltryptamine (DMT) is an endogenous sigma-1 receptor regulator.

    Science.gov (United States)

    Fontanilla, Dominique; Johannessen, Molly; Hajipour, Abdol R; Cozzi, Nicholas V; Jackson, Meyer B; Ruoho, Arnold E

    2009-02-13

    The sigma-1 receptor is widely distributed in the central nervous system and periphery. Originally mischaracterized as an opioid receptor, the sigma-1 receptor binds a vast number of synthetic compounds but does not bind opioid peptides; it is currently considered an orphan receptor. The sigma-1 receptor pharmacophore includes an alkylamine core, also found in the endogenous compound N,N-dimethyltryptamine (DMT). DMT acts as a hallucinogen, but its receptor target has been unclear. DMT bound to sigma-1 receptors and inhibited voltage-gated sodium ion (Na+) channels in both native cardiac myocytes and heterologous cells that express sigma-1 receptors. DMT induced hypermobility in wild-type mice but not in sigma-1 receptor knockout mice. These biochemical, physiological, and behavioral experiments indicate that DMT is an endogenous agonist for the sigma-1 receptor. PMID:19213917

  17. $\\pi$N and strangeness sigma terms at the physical point with chiral fermions

    CERN Document Server

    Yang, Yi-Bo; Draper, Terrence; Liang, Jian; Liu, Keh-Fei

    2015-01-01

    Lattice QCD calculation with chiral fermions for the $\\pi$N sigma term $\\sigma_{\\pi N}$ and strangeness sigma term $\\sigma_{sN}$ including chiral interpolation with continuum and volume corrections are provided in this work. We calculate the scalar matrix element for the light/strange quark directly and find $\\sigma_{\\pi N}=44.4(3.2)(4.5)$ MeV with the disconnected insertion part contributing 30(6)(4)%, and $\\sigma_{sN}=32.3(4.7)(4.9)$ MeV, which is somewhat smaller than $\\sigma_{\\pi N}$. The ratio of the strange/light scalar matrix elements $y$ = 0.058(6)(8).

  18. Characterizing the interplay betwen mulitple levels of organization within bacterial sigma factor regulatory networks

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Qiu [University of California, San Diego; Nagarajan, Harish [University of California, San Diego; Embree, Mallory [University of California, San Diego; Shieu, Wendy [University of California, San Diego; Abate, Elisa [University of California, San Diego; Juarez, Katy [Universidad Nacional Autonoma de Mexico (UNAM); Cho, Byung-Kwan [University of California, San Diego; Elkins, James G [ORNL; Nevin, Kelly P. [University of Massachusetts, Amherst; Barrett, Christian [University of California, San Diego; Lovley, Derek [University of Massachusetts, Amherst; Palsson, Bernhard O. [University of California, San Diego; Zengler, Karsten [University of California, San Diego

    2013-01-01

    Bacteria contain multiple sigma factors, each targeting diverse, but often overlapping sets of promoters, thereby forming a complex network. The layout and deployment of such a sigma factor network directly impacts global transcriptional regulation and ultimately dictates the phenotype. Here we integrate multi-omic data sets to determine the topology, the operational, and functional states of the sigma factor network in Geobacter sulfurreducens, revealing a unique network topology of interacting sigma factors. Analysis of the operational state of the sigma factor network shows a highly modular structure with sN being the major regulator of energy metabolism. Surprisingly, the functional state of the network during the two most divergent growth conditions is nearly static, with sigma factor binding profiles almost invariant to environmental stimuli. This first comprehensive elucidation of the interplay between different levels of the sigma factor network organization is fundamental to characterize transcriptional regulatory mechanisms in bacteria.

  19. Quality management in enterprise using Six Sigma method

    Directory of Open Access Journals (Sweden)

    M. Spilka

    2012-12-01

    Full Text Available Purpose: The article includes characteristic of the extrusion moulding as the most popular method of the plastics processing industry. Statistical analysis and a test of explanation of cause of so-called foam collapsing in the chosen productive enterprise were presented. Six Sigma method was used to the problem solution.Design/methodology/approach: In this paper a detailed plan for implementation of Six Sigma quality management conception in order to eliminate the collapsing effect of polyethylene foam during its cutting was showed. The detailing analysis of the polyethylene foam aging cycle (degassing was carried out. Next the appropriate measures and procedures to eliminate collapsing foam effect were implementation.Findings: Six Sigma leads to an effective improvement of the financial results of the enterprise by controlling and planning of a course of work to minimize waste formation and raw materials consumption. These actions make possible a greater customer satisfaction.Research limitations/implications: In these investigations was established that a decisive influence on the quality of polyethylene foam had the first five days of the seasoning. The proper weather conditions assure obtainment of the product meeting the basic qualitative standards. It was also found that the polyethylene foam rolls which were cut directly after production they were less subject to the process of shrinkage than the rolls cut after several days since the moment of production.Practical implications: Six Sigma is a well-chosen collection of tools which orientate to the approach to improvement and problems solution in the processes. This results the workings which characterize conscientiousness in the everyday work, maturity in the decision making, responsibility in the tasks realization, consequence in applying suitable tools and effective co-operation in the group. Six Sigma method can be used not only in the production but also in logistics, administration

  20. The fitness cost of streptomycin resistance depends on rpsL mutation, carbon source and RpoS (sigmaS).

    Science.gov (United States)

    Paulander, Wilhelm; Maisnier-Patin, Sophie; Andersson, Dan I

    2009-10-01

    Mutations that cause antibiotic resistance often produce associated fitness costs. These costs have a detrimental effect on the fate of resistant organisms in natural populations and could be exploited in designing drugs, therapeutic regimes, and intervention strategies. The streptomycin resistance (StrR) mutations K42N and P90S in ribosomal protein S12 impair growth on rich medium. Surprisingly, in media with poorer carbon sources, the same StrR mutants grow faster than wild type. This improvement reflects a failure of these StrR mutants to induce the stress-inducible sigma factor RpoS (sigmaS), a key regulator of many stationary-phase and stress-inducible genes. On poorer carbon sources, wild-type cells induce sigmaS, which retards growth. By not inducing sigmaS, StrR mutants escape this self-imposed inhibition. Consistent with this interpretation, the StrR mutant loses its advantage over wild type when both strains lack an RpoS (sigmaS) gene. Failure to induce sigmaS produced the following side effects: (1) impaired induction of several stress-inducible genes, (2) reduced tolerance to thermal stress, and (3) reduced translational fidelity. These results suggest that RpoS may contribute to long-term cell survival, while actually limiting short-term growth rate under restrictive growth conditions. Accordingly, the StrR mutant avoids short-term growth limitation but is sensitized to other stresses. These results highlight the importance of measuring fitness costs under multiple experimental conditions not only to acquire a more relevant estimate of fitness, but also to reveal novel physiological weaknesses exploitable for drug development. PMID:19652179

  1. Comparing Linear Sigma Model K-matrix studies of sigma/f0 and the Higgs boson

    International Nuclear Information System (INIS)

    We present a description of the low energy pi pi scattering data using the Linear Sigma Model with K-matrix unitarization. Then we carry out an analogous study of the strongly-coupled minimal Higgs sector of the electroweak theory. We discuss the effect of the unitarization prescription on the WW or ZZ fusion processes and also suggest a related treatment for other Higgs production processes such as gluon fusion

  2. Potential applications for sigma receptor ligands in cancer diagnosis and therapy.

    Science.gov (United States)

    van Waarde, Aren; Rybczynska, Anna A; Ramakrishnan, Nisha K; Ishiwata, Kiichi; Elsinga, Philip H; Dierckx, Rudi A J O

    2015-10-01

    Sigma receptors (sigma-1 and sigma-2) represent two independent classes of proteins. Their endogenous ligands may include the hallucinogen N,N-dimethyltryptamine (DMT) and sphingolipid-derived amines which interact with sigma-1 receptors, besides steroid hormones (e.g., progesterone) which bind to both sigma receptor subpopulations. The sigma-1 receptor is a ligand-regulated molecular chaperone with various ion channels and G-protein-coupled membrane receptors as clients. The sigma-2 receptor was identified as the progesterone receptor membrane component 1 (PGRMC1). Although sigma receptors are over-expressed in tumors and up-regulated in rapidly dividing normal tissue, their ligands induce significant cell death only in tumor tissue. Sigma ligands may therefore be used to selectively eradicate tumors. Multiple mechanisms appear to underlie cell killing after administration of sigma ligands, and the signaling pathways are dependent both on the type of ligand and the type of tumor cell. Recent evidence suggests that the sigma-2 receptor is a potential tumor and serum biomarker for human lung cancer and an important target for inhibiting tumor invasion and cancer progression. Current radiochemical efforts are focused on the development of subtype-selective radioligands for positron emission tomography (PET) imaging. Right now, the mostpromising tracers are [18F]fluspidine and [18F]FTC-146 for sigma-1 receptors and [11C]RHM-1 and [18F]ISO-1 for the sigma-2 subtype. Nanoparticles coupled to sigma ligands have shown considerable potential for targeted delivery of antitumor drugs in animal models of cancer, but clinical studies exploring this strategy in cancer patients have not yet been reported. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers. PMID:25173780

  3. VISA/VRSA (Vancomycin-Intermediate/Resistant Staphylococcus aureus) in Healthcare Settings

    Science.gov (United States)

    ... to vancomycin and other antimicrobial agents. What is Staphylococcus aureus? Staphylococcus aureus is a bacterium commonly found on the ... control personnel. Investigation and Control of Vancomycin-Resistant Staphylococcus aureus (VRSA) [PDF - 300 KB] - This document is ...

  4. Dicarbollylamine ligand as a tunable template for sigma,sigma- and pi,sigma-bonding modes: syntheses, structures, and theoretical studies of eta5:eta1-coordinated constrained-geometry group 13 metal complexes.

    Science.gov (United States)

    Lee, Jong-Dae; Kim, Sung-Kwan; Kim, Tae-Jin; Han, Won-Sik; Lee, Young-Joo; Yoo, Dae-Hwan; Cheong, Minserk; Ko, Jaejung; Kang, Sang Ook

    2008-07-30

    A series of group 13 main group complexes with pi,sigma-type bonding interaction of the formula [{(eta (5)-RC 2B 9H 9)(CH 2)(eta (1)-NMe 2)}MMe] (M = Al, R = H 5, Me 6; Ga, R = H 7, Me 8; In, R = H 9, Me 10) was produced by the reaction of group 13 metal alkyls (MMe 3; M = Al, Ga, In) with the dicarbollylamine ligands, nido-8-R-7,8-C 2B 9H 10-7-(CH 2)NHMe 2 (R = H 1, Me 2). The reactions of 1 and 2 with AlMe 3 in toluene initially afforded tetra-coordinated aluminum complexes with sigma,sigma-type bonding interaction, [{(eta (1)-RC 2B 9H 10)(CH 2)(eta (1)-NMe 2)}AlMe 2] (R = H 3, Me 4), which readily underwent further methane elimination to yield the corresponding constrained geometry complexes (CGCs, 5 and 6) of aluminum with pi,sigma-bonding interaction. However, the reactions between 1 and 2 and MMe 3 (M = Ga, In) in toluene produced gallium and indium pi,sigma-CGCs of 7 and 10 directly, not proceeding through sigma,sigma-intermediates. The structures of group 13 metal CGCs were established by X-ray diffraction studies of 5, 6, and 8, which authenticated a characteristic eta (5):eta (1)-coordination mode of the dicarbollylamino ligand to the group 13 metals. A similar pi,sigma-bonding interaction was also established in ethylene-bridged dicarbollylethylamine series. Thus, aluminum pi,sigma-CGCs of dicarbollylethylamine, [{(eta (5)-RC 2B 9H 9)(CH 2) 2(eta (1)-NBz 2)}AlMe] (R = H 17, Me 18), were prepared by the trans-metalation of the [{(eta (5)-RC 2B 9H 9)(CH 2) 2(eta (1)-NBz 2)}Ti(NMe 2) 2] (R = H 15, Me 16) with AlMe 3. However, only sigma,sigma-bonded complexes of the formula [{(eta (1)-RC 2B 9H 9)(CH 2) 2(eta (1)-NBz 2)}AlMe 2] (R = H 13, Me 14) were isolated by the reaction between [ nido-7-8-R-7,8-C 2B 9H 10-(CH 2) 2HNBz 2] (R = H 11, Me 12) and AlMe 3. When methane-elimination reactions between metal alkyls and dicarbollylamines were carried out with either the gallium atom or monobenzyl aminoethyl tethered ligands, [ nido-7-H 2NBz(CH 2) 2-8-R-7,8-C 2B 9H

  5. A full genomic characterization of the development of a stable Small Colony Variant cell-type by a clinical Staphylococcus aureus strain.

    Science.gov (United States)

    Bui, Long M G; Kidd, Stephen P

    2015-12-01

    A key to persistent and recurrent Staphylococcus aureus infections is its ability to adapt to diverse and toxic conditions. This ability includes a switch into a biofilm or to the quasi-dormant Small Colony Variant (SCV). The development and molecular attributes of SCVs have been difficult to study due to their rapid reversion to their parental cell-type. We recently described the unique induction of a matrix-embedded and stable SCV cell-type in a clinical S. aureus strain (WCH-SK2) by growing the cells with limiting conditions for a prolonged timeframe. Here we further study their characteristics. They possessed an increased viability in the presence of antibiotics compared to their non-SCV form. Their stability implied that there had been genetic changes; we therefore determined both the genome sequence of WCH-SK2 and its stable SCV form at a single base resolution, employing Single Molecular Real-Time (SMRT) sequencing that enabled the methylome to also be determined. The genetic features of WCH-SK2 have been identified; the SCCmec type, the pathogenicity and genetic islands and virulence factors. The genetic changes that had occurred in the stable SCV form were identified; most notably being in MgrA, a global regulator, and RsbU, a phosphoserine phosphatase within the regulatory pathway of the sigma factor SigB. There was a shift in the methylomes of the non-SCV and stable SCV forms. We have also shown a similar induction of this cell-type in other S. aureus strains and performed a genetic comparison to these and other S. aureus genomes. We additionally map RNAseq data to the WCH-SK2 genome in a transcriptomic analysis of the parental, SCV and stable SCV cells. The results from this study represent the unique identification of a suite of epigenetic, genetic and transcriptional factors that are implicated in the switch in S. aureus to its persistent SCV form. PMID:26458527

  6. Vibrationally resolved photoionization of the 1{sigma}{sub g} and 1{sigma}{sub u} shells of N{sub 2} molecule

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, S K [State University of Aerospace Instrumentation, 190000 St Petersburg (Russian Federation); Cherepkov, N A [State University of Aerospace Instrumentation, 190000 St Petersburg (Russian Federation); Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Matsumoto, M [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Fujiwara, K [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Ueda, K [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Kukk, E [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Department of Physics, University of Turku, FIN-20014, Turku (Finland); Tahara, F [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Sunami, T [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Yoshida, H [Department of Physical Science, Hiroshima University, Higashi-Hiroshima 739-8526 (Japan); Tanaka, T [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Nakagawa, K [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Kitajima, M [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); Tanaka, H [Department of Physics, Sophia University, Tokyo 102-8554 (Japan); De Fanis, A [Japan Synchrotron Radiation Research Institute, Sayo-gun, Hyogo 679-5198 (Japan)

    2006-01-28

    Theoretical and experimental study of vibrationally resolved partial photoionization cross sections and angular asymmetry parameter {beta} for the 1{sigma}{sub g} and 1{sigma}{sub u} shells of N{sub 2} molecule in the region of the {sigma}* shape resonance is reported. The measurements were made at the synchrotron radiation facility SPring-8 in Japan. The calculations in the random phase approximation have been performed using the relaxed core Hartree-Fock wavefunctions with the fractional charge of the ion core equal to 0.7. With its help, the role of interchannel coupling between the closely spaced 1{sigma}{sub g} and 1{sigma}{sub u} shells was studied. The experiment demonstrates the existence of a correlational maximum in the 1{sigma}{sub u} shell photoionization cross section induced by the {sigma}* shape resonance in the 1{sigma}{sub g} shell. This maximum reveals itself even more clearly in the angular asymmetry parameter {beta} for the v' = 0 and v' = 1 vibrational states of the ion. The calculation in the random phase approximation gives a consistent interpretation of the experimental data.

  7. The C-Terminal RpoN Domain of sigma54 Forms an unpredictedHelix-Turn-Helix Motif Similar to domains of sigma70

    Energy Technology Data Exchange (ETDEWEB)

    Doucleff, Michaeleen; Malak, Lawrence T.; Pelton, Jeffrey G.; Wemmer, David E.

    2005-11-01

    The ''{delta}'' subunit of prokaryotic RNA-polymerase allows gene-specific transcription initiation. Two {sigma} families have been identified, {sigma}{sup 70} and {sigma}{sup 54}, which use distinct mechanisms to initiate transcription and share no detectable sequence homology. Although the {sigma}{sup 70}-type factors have been well characterized structurally by x-ray crystallography, no high-resolution structural information is available for the {sigma}{sup 54}-type factors. Here we present the NMR derived structure of the C-terminal domain of {sigma}{sup 54} from Aquifex aeolicus. This domain (Thr323 to Gly389), which contains the highly conserved RpoN box sequence, consists of a poorly structured N-terminal tail followed by a three-helix bundle, which is surprisingly similar to domains of the {sigma}{sup 70}-type proteins. Residues of the RpoN box, which have previously been shown to be critical for DNA binding, form the second helix of an unpredicted helix-turn-helix motif. This structure's homology with other DNA binding proteins, combined with previous biochemical data, suggest how the C-terminal domain of {sigma}{sup 54} binds to DNA.

  8. Sigma-1 Receptor Imaging in the Brain : Cerebral sigma-1 receptors and cognition: Small-animal PET studies using 11C-SA4503

    NARCIS (Netherlands)

    Kuzhuppilly Ramakrishnan, Nisha

    2014-01-01

    The sigma-1 receptor is a unique orphan receptor, strongly expressed in neurons and glia. Sigma-1 receptors are involved in several central nervous system (CNS) disorders like depression, anxiety, psychosis, schizophrenia, Parkinson’s disease, Alzheimer’s disease, addiction and neuropathic pain. Sev

  9. Staphylococcus aureus: resistance pattern and risk factors

    Directory of Open Access Journals (Sweden)

    Mohammad Naghavi-Behzad

    2015-03-01

    Full Text Available Introduction: Methicillin resistant Staphylococcus aureus (MRSA has emerged as a nosocomial pathogen of major worldwide importance and is an increasingly frequent cause of community-acquired infections. In this study, different risk factors and MRSA resistance pattern were investigated. Methods: In a 24 months period, all of the patients who were confined to bed in the surgery ward were included in the study. Then they were assessed to find out as if they had MRSA infection when hospitalized and once when they were discharged. Almost 48 h after admission, when patients were discharged, social and medical histories were acquired. Acquired samples were examined. Results: During the present study of 475 patients, 108 patients (22.8% had S. aureus. About frequency of antibiotic resistance among collected S. aureus colonies, erythromycin resistance, was the most frequent antibiotic resistance, also resistance to vancomycin was 0.4% that was the least. Only hospitalization duration had statistically significant correlation with antibiotic resistance, also resistance to erythromycin had statistically significant relation with history of surgery and alcohol consumption. Of all 34 MRSA species, 22 (64.7% samples were resistant to erythromycin, 17 (50.0% resistant to cefoxitin, 5 (14.7% resistant to mupirocin, 1 (2.9% resistant to vancomycin and 1 (2.9% resistant to linezolid. Conclusion: The results of the current study show that among hospitalized patients, there is resistance against methicillin. Since based on results of the study there is resistance against oxacillin and erythromycin in most cases, administering appropriate antibiotics have an important role in minimizing the resistance burden among bacterial species.

  10. Acetylation of poly(ADP-ribose) polymerase-1 by p300/CREB-binding protein regulates coactivation of NF-kappaB-dependent transcription

    OpenAIRE

    Hassa, P O; et al

    2005-01-01

    Poly(ADP-ribose) polymerase-1 (PARP-1) and nuclear factor kappaB (NF-kappaB) have both been demonstrated to play a pathophysiological role in a number of inflammatory disorders. We recently presented evidence that PARP-1 can act as a promoter-specific coactivator of NF-kappaB in vivo independent of its enzymatic activity. PARP-1 directly interacts with p300 and both subunits of NF-kappaB (p65 and p50) and synergistically coactivates NF-kappaB-dependent transcription. Here we show that PARP-1 ...

  11. Dependencia de la Temperatura de Compensaci\\'on en Modelos de Multicapas Ferrimagn\\'eticas de tipo $3(S_{1-x} \\sigma_x)/\\sigma$

    CERN Document Server

    Dalmagro, F A

    2013-01-01

    We investigate numerically the behavior of the compensation temperature, $T_{comp}$, in ferrimagnetic multilayer in the type $3(S_{1-x} \\sigma_x)/\\sigma$ with respect to the increase of the spin concentration $\\sigma_x$, which are randomly distributive in a mix of spins $S = 0, \\pm 1$ and $\\sigma = \\pm 1/2$, with ferromagnetic interaction between spins of the same type, and antiferromagnetic interaction for spins of different type. We have found that $T_{comp}$ decrease slowly with the increase of $x$, until $\\sigma_x$ represent a little more than 40\\% of the spin mixture. For higher concentration values $T_{comp}$ drops abruptly and disappears, as predicted by experimental result.

  12. First Observation of the Cabibbo-suppressed Decays Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+ and Measurement of their Branching Ratios

    CERN Document Server

    Vazquez-Jauregui, E

    2008-01-01

    We report the first observation of two Cabibbo-suppressed decay modes, Xi_c+ -> Sigma+ pi- pi+ and Xi_c+ -> Sigma- pi+ pi+. We observe 56+/-13 over a background of 21, and 23+/-7 over a background of 12 events, respectively, for the signals. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600GeV/c Sigma- beam. The branching ratios of the decays relative to the Cabibbo--favored Xi_c+ -> Xi- pi+ pi+ are measured to be B(Xi_c+ -> Sigma+ pi- pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.50+/-0.20, and B(Xi_c+ -> Sigma- pi+ pi+)/B(Xi_c+ -> Xi- pi+ pi+) = 0.23+/-0.11, respectively. We also report branching ratios for the same decay modes of the Lambda_c+ relative to Lambda_c+ -> p K- pi+.

  13. The interaction of Bacillus subtilis sigmaA with RNA polymerase.

    Science.gov (United States)

    Johnston, Elecia B; Lewis, Peter J; Griffith, Renate

    2009-11-01

    RNA polymerase (RNAP) is an essential and highly conserved enzyme in all organisms. The process of transcription initiation is fundamentally different between prokaryotes and eukaryotes. In prokaryotes, initiation is regulated by sigma factors, making the essential interaction between sigma factors and RNAP an attractive target for antimicrobial agents. Our objective was to achieve the first step in the process of developing novel antimicrobial agents, namely to prove experimentally that the interaction between a bacterial RNAP and an essential sigma factor can be disrupted by introducing carefully designed mutations into sigma(A) of Bacillus subtilis. This disruption was demonstrated qualitatively by Far-Western blotting. Design of mutant sigmas was achieved by computer-aided visualization of the RNAP-sigma interface of the B. subtilis holoenzyme (RNAP + sigma) constructed using a homology modeling approach with published crystal structures of bacterial RNAPs. Models of the holoenzyme and the core RNAP were rigorously built, evaluated, and validated. To allow a high-quality RNAP-sigma interface model to be constructed for the design of mutations, a crucial error in the B. subtilis sigma(A) sequence in published databases at amino acid 165 had to be corrected first. The new model was validated through determination of RNAP-sigma interactions using targeted mutations. PMID:19735077

  14. Development and initial test of the University of Wisconsin global isentropic-sigma model

    Science.gov (United States)

    Zapotocny, Tom H.; Johnson, Donald R.; Reames, Fred M.

    1994-01-01

    The description of a global version of the University of Wisconsin (UW) hybrid isentropic-sigma (theta-sigma) model and the results from an initial numerical weather prediction experiment are presented in this paper. The main objectives of this initial test are to (1) discuss theta-sigma model development and computer requirements, (2) demonstrate the ability of the UW theta-sigma model for global numerical weather prediction using realistic orography and parameterized physical processes, and (3) compare the transport of an inert trace constituent against a nominally 'identical' sigma coordinate model. Initial and verifying data for the 5-day simulations presented in this work were supplied by the Goddard Earth Observing System (GEOS-1) data assimilation system. The time period studied is 1-6 February 1985. This validation experiment demonstrates that the global UW theta-sigma model produces a realistic 5-day simulation of the mass and momentum distributions when compared to both the identical sigma model and GEOS-1 verification. Root-mean-square errors demonstrate that the theta-sigma model is slightly more accurate than the nominally identical sigma model with respect to standard synoptic variables. Of particular importance, the UW theta-sigma model displays a distinct advantage over the conventional sigma model with respect to the prognostic simulation of inert trace constituent transport in amplifying baroclinic waves of the extratropics. This is especially true in the upper troposphere and stratosphere where the spatial integrity and conservation of an inert trace constituent is severely compromised in the sigma model compared to the theta-sigma model.

  15. Using Six Sigma to improve the film library.

    Science.gov (United States)

    Benedetto, Anthony R; Dunnington, Joel S; Oxford-Zelenske, Deborah

    2002-01-01

    The film library of a film-based radiology department is a mission-critical component of the department that is frequently underappreciated and under-staffed. A poorly performing film library causes operational problems for not only the radiology department, but for the institution as a whole. Since Six Sigma techniques had proved successful in an earlier CT throughput improvement project, the University of Texas M.D. Anderson Cancer Center Division of Diagnostic Imaging decided to use Six Sigma techniques to dramatically improve the performance of its film library. Nine mini-project teams were formed to address the basic operating functions of the film library. The teams included film library employees, employees from other sections of radiology, employees from stakeholders outside of radiology, and radiologists and referring physicians, as appropriate to the team's mission. Each Six Sigma team developed a process map of the current process, reviewed or acquired baseline quantitative data to assess the current level of performance, and then modified the process map to incorporate their recommendations for improving the process. An overall project steering committee reviewed recommendations from each Six Sigma team to assure that all of the teams' efforts were coordinated and aligned with the overall project goals. The steering committee also provided advice on implementation strategies, particularly for changes that would have an immediate effect on stakeholders outside of the radiology department. After implementation of recommendations, quantitative data were collected again to determine if the changes were having the desired effect. Improvement in both quantitative metrics and in employee morale have been experienced. We continue to collect data as assurance that the improvements are being sustained over the long haul. Six Sigma techniques, which are as quantitatively-based as possible, are useful in a service-oriented organization, such as a film library. The

  16. Staphylococcus aureus bacteriuria as a prognosticator for outcome of Staphylococcus aureus bacteremia: a case-control study

    Directory of Open Access Journals (Sweden)

    Weinstein Robert A

    2010-07-01

    Full Text Available Abstract Background When Staphylococcus aureus is isolated in urine, it is thought to usually represent hematogenous spread. Because such spread might have special clinical significance, we evaluated predictors and outcomes of S. aureus bacteriuria among patients with S. aureus bacteremia. Methods A case-control study was performed at John H. Stroger Jr. Hospital of Cook County among adult inpatients during January 2002-December 2006. Cases and controls had positive and negative urine cultures, respectively, for S. aureus, within 72 hours of positive blood culture for S. aureus. Controls were sampled randomly in a 1:4 ratio. Univariate and multivariable logistic regression analyses were done. Results Overall, 59% of patients were African-American, 12% died, 56% of infections had community-onset infections, and 58% were infected with methicillin-susceptible S. aureus (MSSA. Among 61 cases and 247 controls, predictors of S. aureus bacteriuria on multivariate analysis were urological surgery (OR = 3.4, p = 0.06 and genitourinary infection (OR = 9.2, p = 0.002. Among patients who died, there were significantly more patients with bacteriuria than among patients who survived (39% vs. 17%; p = 0.002. In multiple Cox regression analysis, death risks in bacteremic patients were bacteriuria (hazard ratio 2.9, CI 1.4-5.9, p = 0.004, bladder catheter use (2.0, 1.0-4.0, p = 0.06, and Charlson score (1.1, 1.1-1.3, p = 0.02. Neither length of stay nor methicillin-resistant Staphylococcus aureus (MRSA infection was a predictor of S. aureus bacteriuria or death. Conclusions Among patients with S. aureus bacteremia, those with S. aureus bacteriuria had 3-fold higher mortality than those without bacteriuria, even after adjustment for comorbidities. Bacteriuria may identify patients with more severe bacteremia, who are at risk of worse outcomes.

  17. Intracellular proliferation of S. aureus in osteoblasts and effects of rifampicin and gentamicin on S. aureus intracellular proliferation and survival

    Directory of Open Access Journals (Sweden)

    W Mohamed

    2014-10-01

    Full Text Available Staphylococcus aureus is the most clinically relevant pathogen regarding implant-associated bone infection and its capability to invade osteoblasts is well known. The aim of this study was to investigate firstly whether S. aureus is not only able to invade but also to proliferate within osteoblasts, secondly to delineate the mechanism of invasion and thirdly to clarify whether rifampicin or gentamicin can inhibit intracellular proliferation and survival of S. aureus. The SAOS-2 osteoblast-like cell line and human primary osteoblasts were infected with S. aureus EDCC5055 and S. aureus Rosenbach 1884. Both S. aureus strains were able to invade efficiently and to proliferate within human osteoblasts. Immunofluorescence microscopy showed intracellular invasion of S. aureus and transmission electron microscopy images could demonstrate bacterial division as a sign of intracellular proliferation as well as cytosolic bacterial persistence. Cytochalasin D, the major actin depolymerisation agent, was able to significantly reduce S. aureus invasion, suggesting that invasion was enabled by promoting actin rearrangement at the cell surface. 7.5 μg/mL of rifampicin was able to inhibit bacterial survival in SAOS-2 cells with almost complete elimination of bacteria after 4 h. Gentamicin could also kill intracellular S. aureus in a dose-dependent manner, an effect that was significantly lower than that observed using rifampicin. In conclusion, S. aureus is not only able to invade but also to proliferate in osteoblasts. Invasion seems to be associated with actin rearrangement at the cell surface. Rifampicin is effective in intracellular eradication of S. aureus whereas gentamicin only poorly eliminates intracellularly replicating bacteria.

  18. Duplex Identification of Staphylococcus aureus by Aptamer and Gold Nanoparticles.

    Science.gov (United States)

    Chang, Tianjun; Wang, Libo; Zhao, Kexu; Ge, Yu; He, Meng; Li, Gang

    2016-06-01

    Staphylococcus aureus is the top common pathogen causing infections and food poisoning. Identification of S. aureus is crucial for the disease diagnosis and regulation of food hygiene. Herein, we report an aptamer-AuNPs based method for duplex identification of S. aureus. Using AuNPs as an indicator, SA23, an aptamer against S. aureus, can well identify its target from Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa. Furthermore, we find citrate-coated AuNPs can strongly bind to S. aureus, but not bind to Salmonella enterica and Proteus mirabilis, which leads to different color changes in salt solution. This colorimetric response is capable of distinguishing S. aureus from S. enteritidis and P. mirabilis. Thus, using the aptasensor and AuNPs together, S. aureus can be accurately identified from the common pathogens. This duplex identification system is a promising platform for simple visual identification of S. aureus. Additionally, in the aptasensing process, bacteria are incubated with aptamers and then be removed before the aptamers adding to AuNPs, which may avoid the interactions between bacteria and AuNPs. This strategy can be potentially applied in principle to detect other cells by AuNPs-based aptasensors. PMID:27427591

  19. Lysostaphin in treatment of neonatal Staphylococcus aureus infection.

    Science.gov (United States)

    Oluola, Okunola; Kong, Lingkun; Fein, Mindy; Weisman, Leonard E

    2007-06-01

    This study describes lysostaphin's effect against methicillin-sensitive Staphylococcus aureus in suckling rats. Standard techniques determined minimal inhibitory and bactericidal concentrations, pharmacokinetics, and efficacy. The numbers of surviving rats after vancomycin, oxacillin, and lysostaphin treatment were comparable and were different from that of controls (P < 0.00001). Lysostaphin appears effective in the treatment of neonatal S. aureus infection. PMID:17420212

  20. Susceptibility of methicillin-resistant Staphylococcus aureus to lysostaphin.

    OpenAIRE

    Huber, M M; Huber, T. W.

    1989-01-01

    One hundred and eleven isolates of methicillin-resistant Staphylococcus aureus recovered from patients at the Olin E. Teague Veterans Center from March 1983 to April 1987 were as susceptible to lysis by lysostaphin as methicillin-susceptible S. aureus controls were.

  1. Mechanism of resistance to some cephalosporins in Staphylococcus aureus.

    OpenAIRE

    Kono, M; Sasatsu, M; O'Hara, K; Shiomi, Y.; HAYASAKA, T.

    1983-01-01

    The mechanism of resistance to some cephalosporins in Staphylococcus aureus strains was investigated with high-pressure liquid chromatography and nuclear magnetic resonance spectrometry. Drug inactivation by penicillinase was found to be the main mechanism of resistance to cefazolin, cephaloridine, and cephalothin in S. aureus.

  2. Activity of and Resistance to Moxifloxacin in Staphylococcus aureus

    OpenAIRE

    Ince, Dilek; Zhang, Xiamei; Hooper, David C.

    2003-01-01

    Moxifloxacin has enhanced potency against Staphylococcus aureus, lower propensity to select for resistant mutants, and higher bactericidal activity against highly resistant strains than ciprofloxacin. Despite similar activity against purified S. aureus topoisomerase IV and DNA gyrase, it selects for topoisomerase IV mutants, making topoisomerase IV the preferred target in vivo.

  3. Changing Trends in Resistance Pattern of Methicillin Resistant Staphylococcus aureus

    OpenAIRE

    Kali, Arunava; Stephen, Selvaraj; Umadevi, Sivaraman; Kumar, Shailesh; Joseph, Noyal Mariya; Srirangaraj, Sreenivasan

    2013-01-01

    Background: Methicillin resistance in Staphylococcus aureus is associated with multidrug resistance, an aggressive course, increased mortality and morbidity in both community and health care facilities. Monitoring of newly emerging and prevalent Methicillin Resistant Staphylococcus aureus (MRSA) strains for their resistance patterns to conventional as well as novel drugs, are essential for infection control.

  4. Effect of Mupirocin on Nasal Carriage of Staphylococcus Aureus

    NARCIS (Netherlands)

    M. Bulanda; M. Gruszka; B. Heczko

    1989-01-01

    textabstractMupirocin eliminates nasal carriage of staphylococcal aureus among medical and surgical personnel for periode varying from several weeks upto one year. In persons recolonized after therapy densites of S. aureus population in nares were much lower than in the same persons before therapy.

  5. Improvement of Production Quality by using Six Sigma Technique:

    Directory of Open Access Journals (Sweden)

    Sawsan Ali

    2013-04-01

    Full Text Available As a result of lack of conformity of the outer diameter of the filling piston of plastic syringe to the specifications set out in the design map and the increased demand for its  products from the Medical syringes factory – Babylon. The research conducts the necessary investigations and  analysis of the production process as most of the units rejected by fact that the outer diameter of the filling piston is smaller than the minimum specification and units returned to work  due to the fact that  the outer diameter larger than the upper limit of the specification.13The research aims firstly to examine the outer diameter of the filling piston through the use of the control chart of the variables represented by the average , and its impact on the production process capability because the increase in diameter specification leads to an increase in the pressure imposed on the lining of the cylinder, causing difficulty in piston movement and a decrease in diameter specification which leads to loose the process capability to prevent leakage of fluid, causing air to enter as well as to speed the movement of the piston, which negatively affects human life in both cases. Secondly, study the possibility of improving the production process capability by using advanced levels of the sigma.The results showed that the production process in the case of a disciplined and follows a normal distribution, the pointer of  the production process capability is equal to (0.55 and the factory works within the level of Sigma equal to (1.65. The proportion of a damaged product is (15.8 % and rework (0.99 %.In order to  reduce the proportion of damaged product, this paper introduces a quality plan depending on ( ±0.025 as tolerance limits instead of ( ±0.05 to increase sigma level by 202%.

  6. SIGMA, a new language for interactive array-oriented computing

    International Nuclear Information System (INIS)

    A description is given of the principles and the main facilities of SIGMA (System for Interactive Graphical Mathematical Applications), a programming language for scientific computing whose major characteristics are: automatic handling of multi-dimensional rectangular arrays as basic data units, interactive operation of the system, and graphical display facilities. After introducing the basic concepts and features of the language, it describes in some detail the methods and operators for the automatic handling of arrays and for their graphical display, the procedures for construction of programs by users, and other facilities of the system. The report is a new version of CERN 73-5. (Auth.)

  7. A calculation of the physical mass of sigma meson

    Indian Academy of Sciences (India)

    J R Morones-Ibarra; Ayax Santos-Guevara

    2007-06-01

    We calculate the physical mass and the width of the sigma meson by considering that it couples in vacuum to two virtual pions. The mass is calculated by using the spectral function, and we find that it is about 600 MeV. In addition, we obtained 220 MeV as the value for the width of its spectral function. The value obtained for the mass is in good agreement with that reported in the Particle Data Book for the σ-meson, which is also named 0(600). This result also shows that -meson can be considered as a two-pion resonance.

  8. New representations for $\\sigma(q)$ via reciprocity theorems

    OpenAIRE

    Banerjee, Koustav; Dixit, Atul

    2016-01-01

    Two new representations for Ramanujan's function $\\sigma(q)$ are obtained. The proof of the first one uses the three-variable reciprocity theorem due to Soon-Yi Kang and a transformation due to R.P. Agarwal while that of the second uses the four-variable reciprocity theorem due to George Andrews and a generalization of a recent transformation of Andrews, Schultz, Yee and the second author. The advantage of these representations is that they involve free complex parameters - one in the first r...

  9. Winding vacuum energies in a deformed O(4) sigma model

    CERN Document Server

    Bazhanov, Vladimir V; Lukyanov, Sergei L

    2014-01-01

    We consider the problem of calculating the Casimir energies in the winding sectors of Fateev's SS-model, which is an integrable two-parameter deformation of the O(4) non-linear sigma model in two dimensions. This problem lies beyond the scope of all traditional methods of integrable quantum field theory including the thermodynamic Bethe ansatz and non-linear integral equations. Here we propose a solution based on a remarkable correspondence between classical and quantum integrable systems and express the winding energies in terms of certain solutions of the classical sinh-Gordon equation.

  10. Spectra of sigma models on semi-symmetric spaces

    Energy Technology Data Exchange (ETDEWEB)

    Cagnazzo, Alessandra; Schomerus, Volker; Tlapak, Vaclav [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group

    2015-12-15

    Sigma models on semi-symmetric spaces provide the central building block for string theories on AdS backgrounds. Under certain conditions on the global supersymmetry group they can be made one-loop conformal by adding an appropriate fermionic Wess-Zumino term. We determine the full one-loop dilation operator of the theory. It involves an interesting new XXZ-like interaction term. Eigenvalues of our dilation operator, i.e. the one-loop anomalous dimensions, are computed for a few examples.

  11. Quantization of the O(N) Nonlinear Sigma Model

    Institute of Scientific and Technical Information of China (English)

    S.I. Muslih

    2002-01-01

    The Hamilton-Jacobi method of quantizing singular systems is discussed. The equations of motion areobtained as total differential equations in many variables. It is shown that if the system is integrable, one can obtain thecanonical phase space coordinates and set of canonical Hamilton-Jacobi partial differential equations without any needto introduce unphysical auxiliary fields. As an example we quantize the O(2) nonlinear sigma model using two differentapproaches: the functional Schrodinger method to obtain the wave functionals for the ground and the exited state andthen we quantize the same model using the canonical path integral quantization as an integration over the canonicalphase-space coordinates.

  12. Semi-leptonic disintegration and integration of sigma hyperon

    International Nuclear Information System (INIS)

    We study processes in which the hyperon sigma decays into one baryon, one pion and a lepton pair. We use the most general form for the matrix element considered, with eight form factors for the vector part of the hadron current and eight for its axial part. We calculate the contributions of soft pions, Born diagrams and the diagram with an intermediate resonance Δ(1232). We obtain the numeric values of the phase space integrals and calculate the disintegration probabilities. We also calculate, the disintegration probability of the process Σ → Δν using the quark model. (author)

  13. The Sigma-Semantics: A Comprehensive Semantics for Functional Programs

    OpenAIRE

    Chitil, Olaf

    1997-01-01

    A comprehensive semantics for functional programs is presented, which generalizes the well-known call-by-value and call-by-name semantics. By permitting a separate choice between call-by value and call-by-name for every argument position of every function and parameterizing the semantics by this choice we abstract from the parameter-passing mechanism. Thus common and distinguishing features of all instances of the sigma-semantics, especially call-by-value and call-by-name semantics, are highl...

  14. Self-Duality of Green-Schwarz Sigma-Models

    OpenAIRE

    Dekel, Amit; Oz, Yaron()

    2011-01-01

    We study fermionic T-duality symmetries of integrable Green-Schwarz sigma-models on Anti-de-Sitter backgrounds with Ramond-Ramond fluxes, constructed as Z_4 supercosets of superconformal algebras. We find three algebraic conditions that guarantee self-duality of the backgrounds under fermionic T-duality, we classify those that satisfy them and construct the map of the monodromy matrix. We introduce new T-duality directions, where some of them contain no bosonic directions, along which the bac...

  15. Oversampled delta-sigma modulators analysis, applications and novel topologies

    CERN Document Server

    Kozak, Mücahit

    2007-01-01

    From the reviews:""This book describes the principles of operation of oversampled (delta sigma symbol) modulators and gives an exact analysis and speed limitations of these non-linear complex circuits. … The book should be useful both as a reference book to graduate students, and researchers and practising engineers in the field of mixed-signal VLSI design. After finishing the text, the total picture of design including analysis, modeling, simulation, and implementation of this type of circuits is presented to the reader. … I highly recommend this book."" (Mile Stojcev, Microelectronics Reliab

  16. A framework to a mass dimension one fermionic sigma model

    CERN Document Server

    Rogerio, R J Bueno; Pereira, S H; da Rocha, Roldao

    2016-01-01

    In this paper a mass dimension one fermionic sigma model, realized by the eigenspinors of the charge conjugation operator with dual helicity (Elko spinors), is developed. Such spinors are chosen as a specific realization of mass dimension one spinors, wherein the non-commutative fermionic feature is ruled by torsion. Moreover, we analyse Elko spinors as a source of matter in a background in expansion. Moreover, we analyse Elko spinors as a source of matter in a background in expansion and we have found that such kind of mass dimension one fermions can serve not only as dark matter but they also induce an effective cosmological constant.

  17. Solitons in a sigma model with a fermionic determinant

    International Nuclear Information System (INIS)

    We develop a numerical technique to calculate the fermionic determinant for soliton states with a hedgehog symmetry in three space dimensions based on the phase shift representation. How the divergence builds up in this approach is clarified. An extrapolation procedure is devised which yields an accurately cutoff independent finite answer. We find that the non-linear sigma model coupled to colored fermions does not seem to support soliton solutions although solutions exist if only scale variations are taken into account. Even on adding a Skyrme quartic term to the action, we find oscillating configurations which are able to lower the energy of the system, possibly without bound

  18. Spectra of sigma models on semi-symmetric spaces

    Science.gov (United States)

    Cagnazzo, Alessandra; Schomerus, Volker; Tlapak, Vaclav

    2016-05-01

    Sigma models on semi-symmetric spaces provide the central building block for string theories on AdS backgrounds. Under certain conditions on the global supersymmetry group they can be made one-loop conformal by adding an appropriate fermionic Wess-Zumino term. We determine the full one-loop dilation operator of the theory. It involves an interesting new XXZ-like interaction term. Eigenvalues of our dilation operator, i.e. the one-loop anomalous dimensions, are computed for a few examples.

  19. Winding vacuum energies in a deformed O(4) sigma model

    International Nuclear Information System (INIS)

    We consider the problem of calculating the Casimir energies in the winding sectors of Fateev's SS-model, which is an integrable two-parameter deformation of the O(4) non-linear sigma model in two dimensions. This problem lies beyond the scope of all traditional methods of integrable quantum field theory including the thermodynamic Bethe ansatz and non-linear integral equations. Here we propose a solution based on a remarkable correspondence between classical and quantum integrable systems and express the winding energies in terms of certain solutions of the classical sinh-Gordon equation

  20. Investigation of $\\eta'N$ system using linear sigma model

    CERN Document Server

    Sakai, Shuntaro

    2016-01-01

    In this paper, we investigate the $\\eta'N$ system using the three-flavor linear sigma model including the effect of the flavor SU(3) symmetry breaking. The $\\eta'N$ bound state is found also in the case including the flavor symmetry braking and the coupling with the $\\eta N$ and $\\pi N$ channels. The $\\eta'N$ interaction becomes more attractive with the inclusion of the flavor symmetry breaking which causes the mixing between the singlet and octet scalar mesons. The existence of such a bound state would have some impact on the $\\eta'$-nucleus system, which is of interest from the theoretical and experimental viewpoint.