1,540 research outputs found

    Inclusive (e,eN)(e,e^\prime N), (e,eNN)(e,e^\prime NN), (e,eπ)(e,e^\prime \pi) ... reactions in nuclei

    Get PDF
    We study the inclusive (e,eN)(e,e^\prime N), (e,eNN)(e,e^\prime NN), (e,eπ)(e,e^\prime \pi), (e,eπN)(e,e^\prime \pi N) reactions in nuclei using a Monte Carlo simulation method to treat the multichannel problem of the final state. The input consists of reaction probabilities for the different steps evaluated using microscopical many body methods. We obtain a good agreement with experiment in some channels where there is data and make predictions for other channels which are presently under investigation in several electron laboratories. The comparison of the theoretical results with experiment for several kinematical conditions and diverse channels can serve to learn about different physical processes ocurring in the reaction. The potential of this theoretical tool to make prospections for possible experiments, aiming at pinning down certain reaction probabilities, is also emphasized.Comment: 21 pages (LaTeX + figure files

    Vortex Dynamics in Dissipative Systems

    Full text link
    We derive the exact equation of motion for a vortex in two- and three- dimensional non-relativistic systems governed by the Ginzburg-Landau equation with complex coefficients. The velocity is given in terms of local gradients of the magnitude and phase of the complex field and is exact also for arbitrarily small inter-vortex distances. The results for vortices in a superfluid or a superconductor are recovered.Comment: revtex, 5 pages, 1 encapsulated postscript figure (included), uses aps.sty, epsf.te

    Correspondences in Arakelov geometry and applications to the case of Hecke operators on modular curves

    Full text link
    In the context of arithmetic surfaces, Bost defined a generalized Arithmetic Chow Group (ACG) using the Sobolev space L^2_1. We study the behavior of these groups under pull-back and push-forward and we prove a projection formula. We use these results to define an action of the Hecke operators on the ACG of modular curves and to show that they are self-adjoint with respect to the arithmetic intersection product. The decomposition of the ACG in eigencomponents which follows allows us to define new numerical invariants, which are refined versions of the self-intersection of the dualizing sheaf. Using the Gross-Zagier formula and a calculation due independently to Bost and Kuehn we compute these invariants in terms of special values of L series. On the other hand, we obtain a proof of the fact that Hecke correspondences acting on the Jacobian of the modular curves are self-adjoint with respect to the N\'eron-Tate height pairing.Comment: 38 pages. Minor correction

    Predicting enhanced absorption of light gases in polyethylene using simplified PC-SAFT and SAFT-VR

    Get PDF
    International audienceAbsorption of light gases in polyethylene (PE) is studied using two versions of the Statistical Associating Fluid Theory (SAFT): SAFT for chain molecules with attractive potentials of variable range (VR) and simplified perturbed-chain (PC) SAFT. Emphasis is placed on the light gases typically present during ethylene polymerisation in the gas-phase reactor (GPR) process. The two approaches are validated using experimental binary-mixture data for gas absorbed in PE, and predictions are made for mixtures of more components. For most cases studied both SAFT versions perform equally well. For the case of ternary mixtures of two gases with PE, it is predicted that the less-volatile of the two gases acts to enhance the absorption of the more-volatile gas, while the more-volatile gas inhibits the absorption of the less-volatile gas. This general behaviour is also predicted in mixtures containing more gases, such as typical reactor mixtures. The magnitude of the effect may vary considerably, depending on the relative proximity of the gas-mixture saturation pressure to the reactor pressure; for example it is predicted that the absorption of ethylene may be approximately doubled if diluent gases, propane or nitrogen, are partially or completely replaced by less-volatile butane or pentane for a reactor pressure similar to 2 MPa. In the case of a co-polymerisation reaction, it is predicted that increases in absorption of both co-monomers may be obtained in roughly equal proportion. Our findings cast light on the so-called co-monomer effect, in which substantial increases in the rate of ethylene polymerisation are observed in the presence of hexene co-monomer, while suggesting that the effect is more general and not restricted to co-monomer. For example, similar rate increases may be expected in the presence of, e.g., pentane instead of hexene, but without the change in the branch structure of the produced polymer that is inevitable when the amount of co-monomer is increased

    Sensitivity Parameter and Time Variations of Fundamental Constants

    Full text link
    The sensitivity parameter is widely used for quantifying fine tuning. However, examples show it fails to give correct results under certain circumstances. We argue that the problems of the sensitivity parameter are almost identical to the consequences we have to solved if the time-varying fine structure constant is proved to be true. The high sensitivity of the energy scale parameter (\Lambda) to the dimensionless coupling constant plays an important role in these problems. It affects the reliability of the sensitivity parameter via mechanisms such as dynamical symmetry breaking, chiral symmetry breaking etc. The reliability of the sensitivity parameter can be improved if it is used properly.Comment: 6 page

    Sodium Intake from Foods Exceeds Recommended Limits in the Spanish Population: The ANIBES Study

    Get PDF
    Excessive sodium consumption is associated with adverse health effects. An elevated dietary intake of salt (sodium chloride) has been related to high blood pressure or hypertension, a major but modifiable risk factor for cardiovascular disease, as well as to other ill health conditions. In the present work, our aim was to describe the contribution of foods to sodium consumption within the Spanish population in a representative sample from the "anthropometric data, macronutrients and micronutrients intake, practice of physical activity, socioeconomic data and lifestyles in Spain" (ANIBES) study (9-75 years), to identify high consumer groups, as well as the major food groups that contribute to sodium intake in the Spanish diet. Intakes were assessed by 3-day food records collected on a tablet device. Sodium intakes across the ANIBES study population exceeded recommendations, as total intakes reached 2025 ± 805 mg of sodium per day, that is approximately 5.06 g/day of salt (excluding discretionary salt, added at the table or during cooking). Sodium intakes were higher in males than in females and within the youngest groups. Main dietary sources of sodium were meat and meat products (27%), cereals and grains (26%), milk and dairy products (14%) and ready-to-eat meals (13%). Given the established health benefits of dietary salt reduction, it would be advisable to continue and even improve the current national initiatives of awareness and educational campaigns and particularly food reformulation to decrease overall salt intakes across the Spanish population

    Inflammation in metabolically healthy and metabolically abnormal adolescents: The HELENA study

    Get PDF
    On behalf of the HELENA study group.[Background and aims] Inflammation may influence the cardio-metabolic profile which relates with the risk of chronic diseases. This study aimed to assess the inflammatory status by metabolic health (MH)/body mass index (BMI) category and to assess how inflammatory markers can predict the cardio-metabolic profile in European adolescents, considering BMI. [Methods and results] A total of 659 adolescents (295 boys) from a cross-sectional European study were included. Adolescents were classified by metabolic health based on age- and sex-specific cut-off points for glucose, blood pressure, triglycerides, high density cholesterol and BMI. C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin (IL-6), complement factors (C3, C4) and cell adhesion molecules were assessed. [Results] Metabolically abnormal (MA) adolescents had higher values of C3 (p < 0.001) and C4 (p = 0.032) compared to those metabolically healthy (MHy). C3 concentrations significantly increased with the deterioration of the metabolic health and BMI (p < 0.001). Adolescents with higher values of CRP had higher probability of being in the overweight/obese-MH group than those allocated in other categories. Finally, high C3 and C4 concentrations increased the probability of having an unfavorable metabolic/BMI status. [Conclusions] Metabolic/BMI status and inflammatory biomarkers are associated, being the CRP, C3 and C4 the most related inflammatory markers with this condition. C3 and C4 were associated with the cardio-metabolic health consistently.The HELENA Study was supported by the European Community Sixth RTD Framework Programme (Contract FOOD-CT-2005-007034) and the Stockholm County Council. This analysis was also supported by the Spanish Ministry of Science and Innovation (JCI-2010-07055) and the gs4:European Regional Development Fund (FEDER). CCS is supported by the Spanish Ministry of Economy and Competitiveness (BES-2014-068829). FBO is supported by a grant from the Spanish Ministry of Science and Innovation (RYC-2011-09011). AIR was funded by a Juan de la Cierva-Formación stipend from the Ministry of Economy and Competitiveness of the Spanish Government (FJCI-2014-19795).Peer Reviewe

    Association between dietary inflammatory index and inflammatory markers in the HELENA study

    Get PDF
    Background: Previous research has shown that diet is associated with low-grade systemic inflammation among adults. However, no study has yet been conducted to explore the association between inflammatory potential of diet and low-grade systemic inflammation among adolescents whose dietary behavior may be different from adults. Methods and Results: We examine the predictive ability of 24-h recall-derived dietary inflammatory index (DII) scores on inflammation among 532 European adolescents in the HELENA cross-sectional study. The DII is a literature-derived dietary index developed to predict inflammation. The DII was calculated per 1000 calories and was tested against C-reactive protein, ILs-1,2,4,10, TNF-alpha, ICAM, vascular cell adhesion molecule (VCAM), and IFN-gamma. All inflammatory markers had nonnormal distributions and therefore were log transformed. Analyses were performed using multivariable linear regression, adjusting for age, sex, city, BMI, smoking, and physical activity. Pro-inflammatory diet (higher DII scores) was associated with increased levels of various inflammatory markers: TNF-alpha, IL-1, 2, IFN-gamma, and vascular cell adhesion molecule (b(DIIt3vs1) = 0.13, 95% CI: 0.001, 0.25; 0.13, 95% CI 0.001, 0.25; 0.40, 95% CI: 0.03, 0.77; 0.53, 95% CI: 0.05, 1.01; 0.07, 95% CI: 0.01, 0.13, respectively). Conclusion: These results reinforce the fact that diet, as a whole, plays an important role in modifying inflammation in adolescents

    BB0172, a Borrelia burgdorferi Outer Membrane Protein That Binds Integrin Α3Β1

    Get PDF
    Lyme disease is a multisystemic disorder caused by Borrelia burgdorferi infection. Upon infection, some B. burgdorferi genes are upregulated, including members of the microbial surface components recognizing adhesive matrix molecule (MSCRAMM) protein family, which facilitate B. burgdorferi adherence to extracellular matrix components of the host. Comparative genome analysis has revealed a new family of B. burgdorferi proteins containing the von Willebrand factor A (vWFA) domain. In the present study, we characterized the expression and membrane association of the vWFA domain-containing protein BB0172 by using in vitro transcription/translation systems in the presence of microsomal membranes and with detergent phase separation assays. Our results showed evidence of BB0172 localization in the outer membrane, the orientation of the vWFA domain to the extracellular environment, and its function as a metal ion-dependent integrin-binding protein. This is the first report of a borrelial adhesin with a metal ion-dependent adhesion site (MIDAS) motif that is similar to those observed in eukaryotic integrins and has a similar function
    corecore