502 research outputs found

    Strong Coupling vs. 4-D Locality in Induced Gravity

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    We re-examine the problem of strong coupling in a regularized version of DGP (or ``brane-induced'') gravity. We find that the regularization of ref. hep-th/0304148 differs from DGP in that it does not exhibit strong coupling or ghosts up to cubic order in the interactions. We suggest that the nonlocal nature of the theory, when written in terms of the 4-D metric, is a plausible reason for this phenomenon. Finally, we briefly discuss the possible behavior of the model at higher-order in perturbation theory.Comment: 19 pages, accepted for publication in PR

    Classical homocystinuria: A common inborn error of metabolism? An epidemiological study based on genetic databases

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    Background: Biallelic pathogenic variants in CBS gene cause the most common form of homocystinuria, the classical homocystinuria (HCU). The worldwide prevalence of HCU is estimated to be 0.82:100,000 [95% CI, 0.39–1.73:100,000] according to clinical records and 1.09:100,000 [95% CI, 0.34–3.55:100,000] by neonatal screening. In this study, we aimed to estimate the minimal worldwide incidence of HCU. Methods: The 25 most common pathogenic alleles of HCU were identified through a literature review. The incidence of HCU was estimated based on the frequency of these common pathogenic alleles in a large genomic database (gnomAD). Results: The minimum worldwide incidence of HCU was estimated to be ~0.38:100,000, and the incidence was higher in Europeans non-Finnish (~0.72:100,000) and Latin Americans (~0.45:100,000) and lower in Africans (~0.20:100,000) and Asians (~0.02:100,000). Conclusion: Our data are in accordance with the only published metanalysis on this topic. To our surprise, the observed incidence of HCU in Europeans was much lower than those described in articles exploring small populations from northern Europe but was similar to the incidence described on the basis of neonatal screening programs. In our opinion, this large dataset analyzed and its population coverage gave us greater precision in the estimation of incidence

    Measuring Human Values in Software Engineering

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    Background: Human values, such as prestige, social justice, and financial success, influence software production decision-making processes. While their subjectivity makes some values difficult to measure, their impact on software motivates our research. Aim: To contribute to the scientific understanding and the empirical investigation of human values in Software Engineering (SE). Approach: Drawing from social psychology, we consider values as mental representations to be investigated on three levels: at a system (L1), personal (L2), and instantiation level (L3). Method: We design and develop a selection of tools for the investigation of values at each level, and focus on the design, development, and use of the Values Q-Sort. Results: From our study with 12 software practitioners, it is possible to extract three values ‘prototypes’ indicative of an emergent typology of values considerations in SE. Conclusions: The Values Q-Sort generates quantitative values prototypes indicating values relations (L1) as well as rich personal narratives (L2) that reflect specific software practices (L3). It thus offers a systematic, empirical approach to capturing values in SE

    Nonlinear Properties of Vielbein Massive Gravity

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    We propose a non-linear extension of the Fierz-Pauli mass for the graviton through a functional of the vielbein and an external Minkowski background. The functional generalizes the notion of the measure, since it reduces to a cosmological constant if the external background is formally sent to zero. Such a term and the explicit external background, emerge dynamically from a bi--gravity theory, having both a massless and a massive graviton in its spectrum, in a specific limit in which the massless mode decouples, while the massive one couples universally to matter. We investigate the massive theory using the Stueckelberg method and providing a 't Hooft-Feynman gauge fixing in which the tensor, vector and scalar Stueckelberg fields decouple. We show that this model has the softest possible ultraviolet behavior which can be expected from any generic (Lorentz invariant) theory of massive gravity, namely that it becomes strong only at the scale Lambda_3 = (m_g^2 M_P)^{1/3}.Comment: 23+1 pages LaTeX, 3 figures, few typos correcte

    Fibrinogen concentrate for treatment of bleeding and surgical prophylaxis in congenital fibrinogen deficiency patients

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    Background: Congenital fibrinogen deficiency is an ultra-rare disorder in which patients can experience severe and/or frequent bleeding episodes (BEs). Here, we present the largest prospective study to date on the treatment of this disorder. Methods: Hemostatic efficacy of human fibrinogen concentrate (HFC; FIBRYGA\uae, Octapharma AG) for treatment of bleeding or surgical prophylaxis was assessed by investigators and adjudicated by an independent data monitoring and endpoint adjudication committee (IDMEAC) according to a four-point scale, using objective criteria. Thromboelastometry maximum clot firmness (MCF) was also determined. Results: Twenty-five afibrinogenemia patients were treated with HFC: 24 for on-demand treatment of 89 BEs, and nine as prophylaxis for 12 surgeries. For BEs, treatment success (rating of excellent or good) evaluated by investigators was 96.6% (90% confidence interval [CI], 0.92-0.99; two missing ratings, classified as failures) and by the IDMEAC was 98.9% (90% CI, 0.95-0.999). Mean \ub1 standard deviation (SD) increase in MCF was 5.8 \ub1 2.5 mm one hour after the first HFC infusion (mean \ub1 SD dose, 61.88 \ub1 11.73 mg/kg). For the 12 surgeries (median [range] HFC dose/surgery, 85.80 mg/kg [34.09-225.36]), intraoperative and postoperative treatment success were both rated 100% (90% CI, 0.82-1.00) by investigators and the IDMEAC. Three adverse events were possibly treatment related, including a moderate case of thrombosis. There were no deaths, no severe allergic or hypersensitivity reactions, and no clinical evidence of neutralizing antifibrinogen antibodies. Conclusions: Human fibrinogen concentrate was efficacious for on-demand treatment of bleeding and as surgical prophylaxis, with a favorable safety profile, in patients with congenital afibrinogenemia

    Transport properties of strongly correlated metals:a dynamical mean-field approach

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    The temperature dependence of the transport properties of the metallic phase of a frustrated Hubbard model on the hypercubic lattice at half-filling are calculated. Dynamical mean-field theory, which maps the Hubbard model onto a single impurity Anderson model that is solved self-consistently, and becomes exact in the limit of large dimensionality, is used. As the temperature increases there is a smooth crossover from coherent Fermi liquid excitations at low temperatures to incoherent excitations at high temperatures. This crossover leads to a non-monotonic temperature dependence for the resistance, thermopower, and Hall coefficient, unlike in conventional metals. The resistance smoothly increases from a quadratic temperature dependence at low temperatures to large values which can exceed the Mott-Ioffe-Regel value, hbar a/e^2 (where "a" is a lattice constant) associated with mean-free paths less than a lattice constant. Further signatures of the thermal destruction of quasiparticle excitations are a peak in the thermopower and the absence of a Drude peak in the optical conductivity. The results presented here are relevant to a wide range of strongly correlated metals, including transition metal oxides, strontium ruthenates, and organic metals.Comment: 19 pages, 9 eps figure

    Fusarium wilt incidence and common bean yield according to the preceding crop and the soil tillage system

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    The objective of this work was to evaluate the effects of preceding crops and tillage systems on the incidence of Fusarium wilt (Fusarium oxysporum f. sp. phaseoli) and common bean (Phaseolus vulgaris) yield. The cultivar BRS Valente was cultivated under center‑pivot irrigation in the winter seasons of 2003, 2004 and 2005, after several preceding crops established in the summer seasons. Preceding crops included the legumes Cajanus cajan (pigeon pea), Stylosanthes guianensis, and Crotalaria spectabilis; the grasses Pennisetum glaucum (millet), Sorghum bicolor (forage sorghum), Panicum maximum, and Urochloa brizantha; and a consortium of maize (Zea mays) and U. brizantha (Santa FĂ© system). Experiments followed a strip‑plot design, with four replicates. Fusarium wilt incidence was higher in the no‑tillage system. Higher disease incidences corresponded to lower bean yields in 2003 and 2004. Previous summer cropping with U. brizantha, U. brizantha + maize consortium, and millet showed the lowest disease incidence. Therefore, the choice of preceding crops must be taken into account for managing Fusarium wilt on irrigated common bean crops in the Brazilian Cerrado

    Measurements of exclusive B_s^0 decays at the Y(5S) resonance

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    Several exclusive Bs0B_s^0 decays are studied using a 1.86 fb-1 data sample collected at the Y(5S) resonance with the Belle detector at the KEKB asymmetric energy e^+ e^- collider. In the Bs0→Ds−π+B_s^0 \to D_s^- \pi^+ decay mode we find 10 Bs0B_s^0 candidates and measure the corresponding branching fraction. Combining the B_s^0 -> D_s^{(*)-} \pi^+, B_s^0 -> D_s^{(*)-} \rho^+, B_s^0 -> J/\psi \phi and B_s^0 -> J/\psi \eta decay modes, a significant Bs0B_s^0 signal is observed. The ratio \sigma (e^+ e^- -> B_s^* \bar{B}_s^*) / \sigma (e^+ e^- -> B_s^{(*)} \bar{B}_s^{(*)}) = (93^{+7}_{-9} \pm 1)% is obtained at the Y(5S) energy, indicating that Bs0B_s^0 meson production proceeds predominantly through the creation of Bs∗Bˉs∗B^*_s \bar{B}^*_s pairs. The Bs0B_s^0 and Bs∗B_s^* meson masses are measured to be M(B_s^0)=(5370 \pm 1 \pm 3)MeV/c^2 and M(B_s^*)=(5418 \pm 1 \pm 3)MeV/c^2. Upper limits on the B_s^0 -> \gamma \gamma, B_s^0 -> \phi \gamma, B_s^0 -> K^+ K^- and B_s^0 -> D_s^{(*)+} D_s^{(*)-} branching fractions are also reported.Comment: 9 pages, 5 figures, published in Phys. Rev. D76, 012002 (2007

    Measurement of the near-threshold e+e−→DDˉe^+e^- \to D \bar D cross section using initial-state radiation

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    We report measurements of the exclusive cross section for e+e−→DDˉe^+e^- \to D \bar D , where D=D0D=D^0 or D+D^+, in the center-of-mass energy range from the DDˉD \bar D threshold to 5GeV/c25\mathrm{GeV}/c^2 with initial-state radiation. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of 673 fb−1\mathrm{fb}^{-1}.Comment: Presented at EPS07 and LP07 conferences, published in PRD(RC
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