111,416 research outputs found

    Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV

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    The prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region

    A fuzzy approach for sequencing interrelated activities in a DSM

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    Production and manufacturing systems often involve a myriad of interrelated activities. How these activities are organised and scheduled has a significant effect on the success of a system. Recently, the Design Structure Matrix (DSM) has been regarded as an effective tool for modelling and scheduling interrelated activities. Based on fuzzy set theory, this study explicitly addresses the uncertain activity dependencies in our formulation and develops a mathematical model for sequencing interrelated activities in a DSM. Because of the complexity of the model, a new approach, which embeds an exact algorithm within a framework of a local search heuristic, is presented for solving large problem instances. Testing results demonstrate that relatively good solutions can be easily obtained by our approach, thereby providing managers with an effective tool for scheduling a large number of interrelated activities with uncertain dependencies. © 2012 Copyright Taylor and Francis Group, LLC.Abdelsalam HME, 2006, IEEE T ENG MANAGE, V53, P69, DOI 10.1109-TEM.2005.861805; Ahmadi R, 2001, EUR J OPER RES, V130, P539, DOI 10.1016-S0377-2217(99)00412-9; Banerjee A, 2007, IIE TRANS, V39, P453, DOI 10.1080-07408170601180510; Browning TR, 2001, IEEE T ENG MANAGE, V48, P292, DOI 10.1109-17.946528; Chen CH, 2004, INT J PROD RES, V42, P4623, DOI 10.1080-00207540410001721727; Chen SJ, 2003, COMPUT IND ENG, V44, P435, DOI 10.1016-S0360-8352(02)00230-9; Debels D, 2007, OPER RES, V55, P457, DOI 10.1287-opre.1060.0358; Dubois D., 2000, FUNDAMENTALS FUZZY S; Dubois D, 2003, EUR J OPER RES, V147, P231, DOI 10.1016-S0377-2217(02)00558-1; EPPINGER SD, 1994, RES ENG DES, V6, P1, DOI 10.1007-BF01588087; Eppinger SD, 2001, HARVARD BUS REV, V79, P149; Fortemps P, 1996, FUZZY SET SYST, V82, P319, DOI 10.1016-0165-0114(95)00273-1; Guschinskaya O, 2008, EUR J OPER RES, V189, P902, DOI 10.1016-j.ejor.2006.03.072; Karniel A, 2009, IEEE T ENG MANAGE, V56, P636, DOI 10.1109-TEM.2009.2032032; Karniel A, 2005, COMPUT AIDED DESIGN, V37, P399, DOI 10.1016-j.cad.2004.06.015; KUSIAK A, 1993, INT J PROD RES, V31, P753, DOI 10.1080-00207549308956755; Lancaster J, 2008, INT J PROD RES, V46, P5043, DOI 10.1080-00207540701324176; Li D., 2006, NONLINEAR INTEGER PR; Lin J, 2009, EUR J OPER RES, V196, P1158, DOI 10.1016-j.ejor.2008.05.030; Lin J, 2010, EUR J OPER RES, V201, P737, DOI 10.1016-j.ejor.2009.03.040; Lin J, 2008, EUR J OPER RES, V185, P378, DOI 10.1016-j.ejor.2006.12.022; Luh DB, 2009, CONCURRENT ENG-RES A, V17, P43, DOI 10.1177-1063293X09102249; McCulley C, 1996, STRUCT OPTIMIZATION, V12, P186, DOI 10.1007-BF01196956; Meier C, 2007, J MECH DESIGN, V129, P566, DOI 10.1115-1.2717224; Palpant M, 2004, ANN OPER RES, V131, P237, DOI 10.1023-B:ANOR.0000039521.26237.62; Qian YJ, 2011, IEEE T ENG MANAGE, V58, P688, DOI 10.1109-TEM.2011.2107558; Rowles C. M., 1999, THESIS MIT; Shaja AS, 2010, RES ENG DES, V21, P173, DOI 10.1007-s00163-009-0082-5; Smith RP, 1997, MANAGE SCI, V43, P1104, DOI 10.1287-mnsc.43.8.1104; Smith RP, 1998, CONCURRENT ENG-RES A, V6, P15, DOI 10.1177-1063293X9800600103; Steward D. V., 1981, IEEE T ENG MANAGE, V49, P428; Tang DB, 2010, ADV ENG INFORM, V24, P159, DOI 10.1016-j.aei.2009.08.005; Tang DB, 2000, COMPUT IND ENG, V38, P479, DOI 10.1016-S0360-8352(00)00059-0; Tang DB, 2009, CONCURRENT ENG-RES A, V17, P129, DOI 10.1177-1063293X09105348; YAGER RR, 1981, INFORM SCIENCES, V24, P143, DOI 10.1016-0020-0255(81)90017-7; Yassine A, 2003, CONCURRENT ENG-RES A, V11, P165, DOI 10.1177-106329303034503; Zimmermann H.-J., 1996, FUZZY SET THEORY ITS32

    Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′

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    First evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)

    A functional variant in the promoter region regulates the C-reactive protein gene and is a potential candidate for increased risk of atrial fibrillation

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    . Chang S-N, Tsai C-T, Wu C-K, Lee J-K, Lai L-P, Huang S-W, Huang L-Y, Tseng C-D, Lin J-L, Chiang F-T, Hwang J-J (National Taiwan University Hospital Yun-Lin Branch, Yun-Lin; National Taiwan University Hospital, Taipei; National Taiwan University Hospital, Taipei; Institute of Pharmacology, Taipei; and Graduate Institute of Biomedical Engineering, Taipei, Taiwan). A functional variant in the promoter region regulates the C-reactive protein gene and is a potential candidate for increased risk of atrial fibrillation. J Intern Med 2012; 272: 305315. Objectives. In a large population-based cohort, the level of C-reactive protein (CRP) in patients at baseline predicts an increased risk of future development of atrial fibrillation (AF). The mechanism of this increased risk is unknown. Furthermore, both the molecular effects of CRP on atrial myocytes and fibroblasts and whether genetic variants in the CRP gene predispose to AF are also unknown. Methods.similar to A genetic association study between CRP gene polymorphisms and AF was performed in two independent populations (I: 100 AF patients and 101 controls; II: 348 AF patients and 356 controls), with functional studies to elucidate the mechanism of association. Results.similar to Three polymorphisms (T-861C, A-821G and C-390A/C-390T) were found in the 1-kb promoter of CRP. A triallelic polymorphism (C-390A/C-390T) captured all haplotype information and determined the CRP gene promoter activity and the plasma CRP level, and was in nearly complete linkage disequilibrium with G1059C polymorphism in exon 2. The -390A variant was associated with a higher CRP gene promoter activity, a higher plasma CRP level and a higher risk of AF. Patients with AF also had a higher plasma CRP level than controls. CRP significantly increased the inward L-type calcium current in atrial myocytes with no changes in other ionic currents. CRP did not affect the expressions of type I alpha 1 (COL1A1), type III alpha 1 (COL3A1) and type 1 alpha 2 (COL1A2) procollagens in atrial fibroblasts. Conclusion.similar to A CRP gene promoter triallelic polymorphism was associated with CRP gene promoter activity, determined the plasma level of CRP, and predicted the risk of AF. The mechanism of this may be via augmention of calcium influx by CRP in atrial myocytes, but not because of atrial fibrosis
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