Ionic conductivity on a wetting surface

Recent experiments measuring the electrical conductivity of DNA molecules highlight the need for a theoretical model of ion transport along a charged surface. Here we present a simple theory based on the idea of unbinding of ion pairs. The strong humidity dependence of conductivity is explained by the decrease in the electrostatic self-energy of a separated pair when a layer of water (with high dielectric constant) is adsorbed to the surface. We compare our prediction for conductivity to experiment, and discuss the limits of its applicability.Comment: 5 pages, 3 figures; one section and two illustrations added; figures updated and discussion added; typo fixe

Statistical mechanical theory of an oscillating isolated system. The relaxation to equilibrium

In this contribution we show that a suitably defined nonequilibrium entropy of an N-body isolated system is not a constant of the motion in general and its variation is bounded, the bounds determined by the thermodynamic entropy, i.e., the equilibrium entropy. We define the nonequilibrium entropy as a convex functional of the set of n-particle reduced distribution functions (n=0,......., N) generalizing the Gibbs fine-grained entropy formula. Additionally, as a consequence of our microscopic analysis we find that this nonequilibrium entropy behaves as a free entropic oscillator. In the approach to the equilibrium regime we find relaxation equations of the Fokker-Planck type, particularly for the one-particle distribution function

A near-infrared spectroscopic screening of the red giant populations in omega Centauri

Near-infrared spectra of 21 giants in omega Centauri, spanning the whole range of metallicities observed in this cluster, are presented. This work is part of a coordinated photometric and spectroscopic campaign in the optical and in the infrared, aimed at studying the complex stellar population of omega Centauri and understanding its formation and chemical evolution. By analyzing the several CO and OH molecular bands and atomic lines in the spectra of the selected giants, metal abundances and abundance ratios have been obtained. The existence of three major metallicity regimes at [Fe/H]=-1.6, -1.2 and [Fe/H]<-0.5 has been confirmed. The most metal-rich stars in our sample show a lower (if any) alpha-enhancement when compared to the more metal-poor components, suggesting that they should have formed in a medium significantly polluted by type Ia supernova ejecta. Isotopic carbon abundances have been also inferred, providing an average 13C/12C=4, which clearly indicates that extra-mixing processes occurred in the stellar interiors during the ascent on the Red Giant Branch.Comment: 22 pages, 7 .ps figures. aastex. Accepted for pubilcation in the Astrophysical Journa

Fluctuation theorem for currents and Schnakenberg network theory

A fluctuation theorem is proved for the macroscopic currents of a system in a nonequilibrium steady state, by using Schnakenberg network theory. The theorem can be applied, in particular, in reaction systems where the affinities or thermodynamic forces are defined globally in terms of the cycles of the graph associated with the stochastic process describing the time evolution.Comment: new version : 16 pages, 1 figure, to be published in Journal of Statistical Physic

Flavour Universal Dynamical Electroweak Symmetry Breaking

The top condensate see-saw mechanism of Dobrescu and Hill allows electroweak symmetry to be broken while deferring the problem of flavour to an electroweak singlet, massive sector. We provide an extended version of the singlet sector that naturally accommodates realistic masses for all the standard model fermions, which play an equal role in breaking electroweak symmetry. The models result in a relatively light composite Higgs sector with masses typically in the range of (400-700)~GeV. In more complete models the dynamics will presumably be driven by a broken gauged family or flavour symmetry group. As an example of the higher scale dynamics a fully dynamical model of the quark sector with a GIM mechanism is presented, based on an earlier top condensation model of King using broken family gauge symmetry interactions (that model was itself based on a technicolour model of Georgi). The crucial extra ingredient is a reinterpretation of the condensates that form when several gauge groups become strong close to the same scale. A related technicolour model of Randall which naturally includes the leptons too may also be adapted to this scenario. We discuss the low energy constraints on the massive gauge bosons and scalars of these models as well as their phenomenology at the TeV scale.Comment: 22 pages, 3 fig

Effect of agriculture on Cedar Lake water quality

Cover title.Includes bibliographical references (p. 56-59)

Impact of wastes from a water treatment plant: Evaluative procedures and results

Cover title.Includes bibliographical references (p. 27)

Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL), and higher body fat percentage (29.2±7.9% versus 23.2±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk