A control on quantum fluctuations in 2+1 dimensions

A functional method is discussed, where the quantum fluctuations of a theory are controlled by a mass parameter and the evolution of the theory with this parameter is connected to its renormalization. It is found, in the framework of the gradient expansion, that the coupling constant of a N=1 Wess-Zumino theory in 2+1 dimensions does not get quantum corrections.Comment: Comments adde

Short-term relationships between emergency hospital admissions for respiratory and cardiovascular diseases and fine particulate air pollution in Beirut, Lebanon

International audienceHigh levels of major outdoor air pollutants have been documented in Lebanon, but their health effects remain unknown. The Beirut Air Pollution and Health Effects study aimed to determine the relationship between short-term variations in ambient concentrations of particulate matter (PM10 and PM2.5) and emergency hospital admissions in the city of Beirut, and whether susceptible groups are more greatly affected. An autoregressive Poisson model was used to evaluate the association between daily concentrations of particulate matter and respiratory and cardiovascular emergency hospital admissions after controlling for confounders. All variables were measured during 1 year from January 2012 to December 2012. Relative risks of admissions for respiratory and cardiovascular diseases were calculated for an increase in 10 μg.m−3 of pollutant concentrations. Total respiratory admissions were significantly associated with the levels of PM10 (1.012 [95 % CI 1.004–1.02]) per 10 μg.m−3 rise in daily mean pollutant concentration for PM10 and 1.016 [95 % CI 1.000–1.032] for PM2.5 on the same day. With regard to susceptible groups, total respiratory admissions were associated with PM2.5 and PM10 within the same day in children (relative risk (RR), 1.013 and 1.014; 95 % confidence interval, 0.985–1.042 and 1.000–1.029 for PM2.5 and PM10, respectively). Moreover, a nearly significant association was found between particles and total circulatory admissions for adults and elderly groups in the same day. These results are similar to other international studies. Therefore, air pollution control is expected to reduce the number of admissions of these diseases in Lebanon

Wild-derived mouse stocks: an underappreciated tool for aging research

Virtually all biomedical research makes use of a relatively small pool of laboratory-adapted, inbred, isogenic stocks of mice. Although the advantages of these models are many, there are a number of disadvantages as well. When studying a multifaceted process such as aging, the problems associated with using laboratory stocks are greatly inflated. On the other hand, wild-derived mouse stocks, loosely defined here as either wild-caught individuals or the recent progeny of wild-caught individuals, have much to offer to biogerontology research. Hence, the aims of this review are threefold: (1) to (re)acquaint readers with the pros and cons of using a typical inbred laboratory mouse model for aging research; (2) to reintroduce the notion of using wild-derived mouse stocks in aging research as championed by Austad, Miller and others for more than a decade, and (3) to provide an overview of recent advances in biogerontology using wild-derived mouse stocks

A measurement of the B0−B0ˉB^{0}-\bar{B^0} oscillation frequency and determination of flavor-tagging efficiency using semileptonic and hadronic B0B^{0} decays

B^0-anti-B^0 flavor oscillations are studied in e^+e^- annihilation data collected with the BABAR detector at center-of-mass energies near the Y(4S) resonance. One B is reconstructed in a hadronic or semileptonic decay mode, and the flavor of the other B in the event is determined with a tagging algorithm that exploits the relation between the flavor of the heavy quark and the charges of its decay products. Tagging performance is characterized by an efficiency e_i and a probability for mis-identification, w_i, for each tagging category. We report a determination of the wrong-tag probabilities, w_i, and a preliminary result for the time-dependent B^0-anti-B^0 oscillation frequency, Delta_md = 0.512+/-0.017+/-0.022 hbar-ps^{-1}

Study of inclusive DS(∗)+/−D_S^{(*)+/-} production in B decays and measurement of B0→D∗−DS(∗)+B^0 \to D^{*-}D_S^{(*)+} decays using a partial reconstruction technique

Electron-positron annihilation data collected by the BABAR detector near the Y(4S) resonance are used to study the inclusive decay of B mesons to D_S^(+/-) and D_S^(*+/-) mesons, where the D_S^(+/-) is reconstructed using the decay D_S^(+/-) --> phi pi^(+/-). The production fraction of inclusive D_S^((*)+/-) and the corresponding momentum spectra have been determined. The exclusive decays B^0 --> D^(*-)D_S^((*)+) are observed with a partial reconstruction technique which uses the soft pion from the D^(*+/-) decay in association with the reconstructed D_S^((*)+/-). The beam energy constraint is used to determine the missing mass recoiling against the D_S^(+/-) system, showing a clear signal for this process. From the observed rates, preliminary results for the corresponding branching fractions have been obtained