Smoking-induced long-lasting modifications of human platelet serotonin catabolism through a MAO epigenetic regulation

Postulating that serotonin, secreted from smoking-activated platelets, could be involved in smoking-induced vascular modifications, we studied 115 men distributed in smokers (S), former smokers (FS) and never smokers (NS). The platelet serotonin content was similar in S and NS but lower in FS. This was unexpected because the monoamine oxidase (MAO) activity, which catabolizes serotonin, was inhibited during smoking. However, the amount of platelet MAO was higher in S and FS than in NS. The persistent elevated MAO amount in FS prompted us to study the methylation of its gene promoter in an additional series of patients: it was markedly lower for S and FS vs. NS due to cigarette smoke-induced increase of nucleic acid demethylase activity. This smoking-induced demethylation of the MAO gene promoter, resulting in high MAO amount persisting long after quitting smoking, has cardiovascular consequences and could impact fields such as behavior, mental health, and cancer

Orientation of Nd3+^{3+} dipoles in yttrium aluminum garnet: A simple yet accurate model

We report an experimental study of the 1064nm transition dipoles in neodymium doped yttrium aluminum garnet (Nd-YAG) by measuring the coupling constant between two orthogonal modes of a laser cavity for different cuts of the YAG gain crystal. We propose a theoretical model in which the transition dipoles, slightly elliptic, are oriented along the crystallographic axes. Our experimental measurements show a very good quantitative agreement with this model, and predict a dipole ellipticity between 2% and 3%. This work provides an experimental evidence for the simple description in which transition dipoles and crystallographic axes are collinear in Nd-YAG (with an accuracy better than 1 deg), a point that has been discussed for years.Comment: Accepted for publication in Physical Review

Automatic Verification of Bossa Scheduler Properties

Bossa is a development environment for operating-system process schedulers that provides numerous safety guarantees. In this paper, we show how to automate the checking of safety properties of a scheduling policy developed in this environment. We find that most of the relevant properties can be considered as invariant or refinement properties. In order to automate the related proof obligations, we use the WS1S logic for which a decision procedure is implemented by Mona. The proof techniques are implemented using the FMona tool

An accurate equation of state for the one component plasma in the low coupling regime

An accurate equation of state of the one component plasma is obtained in the low coupling regime $0 \leq \Gamma \leq 1$. The accuracy results from a smooth combination of the well-known hypernetted chain integral equation, Monte Carlo simulations and asymptotic analytical expressions of the excess internal energy $u$. In particular, special attention has been brought to describe and take advantage of finite size effects on Monte Carlo results to get the thermodynamic limit of $u$. This combined approach reproduces very accurately the different plasma correlation regimes encountered in this range of values of $\Gamma$. This paper extends to low $\Gamma$'s an earlier Monte Carlo simulation study devoted to strongly coupled systems for $1 \leq \Gamma \leq 190$ ({J.-M. Caillol}, {J. Chem. Phys.} \textbf{111}, 6538 (1999)). Analytical fits of $u(\Gamma)$ in the range $0 \leq \Gamma \leq 1$ are provided with a precision that we claim to be not smaller than $p= 10^{-5}$. HNC equation and exact asymptotic expressions are shown to give reliable results for $u(\Gamma)$ only in narrow $\Gamma$ intervals, i.e. $0 \leq \Gamma \lesssim 0.5$ and $0 \leq \Gamma \lesssim 0.3$ respectively

Neutron scattering study of the long-range ordered state in CeRu2Al10

Elastic and inelastic neutron scattering measurements have been performed on powder and single-crystal samples of orthorhombic CeRu2Al10. The order forming below T0 = 27 K was identified as a long-range antiferromagnetic state with the wave vector k = (1,0,0). The magnetic spectral response in the ordered phase, measured on powder, is characterized by a spin gap and a pronounced peak at 8 meV, whose Q dependence suggests a magnetic origin. Both features are suppressed when temperature is raised to T0, and a conventional relaxational behavior is observed at 40 K. This peculiar spin dynamics is discussed in connection with recent magnetization results for the same compound.Comment: 5 pages, 5 figures, International Conference on Heavy Electrons 2010 (Tokyo Metropolitan University, September 17 - 20, 2010), to be published in Journal of the Physical Society of Japan. Typo corrected p. 3: "sites denoted 1 and 3" => "1 and 4

Hydraulic Modeling of a Mixed Water Level Control Hydromechanical Gate

This article describes the hydraulic behavior of a mixed water level control hydromechanical gate present in several irrigation canals. The automatic gate is termed "mixed" because it can hold either the upstream water level or the downstream water level constant according to the flow conditions. Such a complex behavior is obtained through a series of side tanks linked by orifices and weirs. No energy supply is needed in this regulation process. The mixed flow gate is analyzed and a mathematical model for its function is proposed, assuming the system is at equilibrium. The goal of the modeling was to better understand the mixed gate function and to help adjust their characteristics in the field or in a design process. The proposed model is analyzed and evaluated using real data collected on a canal in the south of France. The results show the ability of the model to reproduce the function of this complex hydromechanical system. The mathematical model is also implemented in software dedicated to hydraulic modeling of irrigation canals, which can be used to design and evaluate management strategies

Vector theories in cosmology

This article provides a general study of the Hamiltonian stability and the hyperbolicity of vector field models involving both a general function of the Faraday tensor and its dual, $f(F^2,F\tilde F)$, as well as a Proca potential for the vector field, $V(A^2)$. In particular it is demonstrated that theories involving only $f(F^2)$ do not satisfy the hyperbolicity conditions. It is then shown that in this class of models, the cosmological dynamics always dilutes the vector field. In the case of a nonminimal coupling to gravity, it is established that theories involving $R f(A^2)$ or $Rf(F^2)$ are generically pathologic. To finish, we exhibit a model where the vector field is not diluted during the cosmological evolution, because of a nonminimal vector field-curvature coupling which maintains second-order field equations. The relevance of such models for cosmology is discussed.Comment: 17 pages, no figur

Vibrational dynamics of confined granular material

By means of two-dimensional contact dynamics simulations, we analyze the vibrational dynamics of a confined granular layer in response to harmonic forcing. We use irregular polygonal grains allowing for strong variability of solid fraction. The system involves a jammed state separating passive (loading) and active (unloading) states. We show that an approximate expression of the packing resistance force as a function of the displacement of the free retaining wall from the jamming position provides a good description of the dynamics. We study in detail the scaling of displacements and velocities with loading parameters. In particular, we find that, for a wide range of frequencies, the data collapse by scaling the displacements with the inverse square of frequency, the inverse of the force amplitude and the square of gravity. Interestingly, compaction occurs during the extension of the packing, followed by decompaction in the contraction phase. We show that the mean compaction rate increases linearly with frequency up to a characteristic frequency and then it declines in inverse proportion to frequency. The characteristic frequency is interpreted in terms of the time required for the relaxation of the packing through collective grain rearrangements between two equilibrium states