Large deviations in the alternating mass harmonic chain

We extend the work of Kannan et al. and derive the cumulant generating function for the alternating mass harmonic chain consisting of N particles and driven by heat reservoirs. The main result is a closed expression for the cumulant generating function in the thermodynamic large N limit. This expression is independent of N but depends on whether the chain consists of an even or an odd number of particles, in accordance with the results obtained by Kannan el al. for the heat current. This result is in accordance with the absence of local thermodynamic equilibrium in a linear system.Comment: 19 pages latex, 6 figures, final version, appeared in J. Phys. A: Math. Theor 47, 325003 (2014

Comment on "A 'local observables' method for wave mechanics applied to atomic hydrogen," by Peter Bowman [Am. J. Phys. 76, 1120-1129 (2008)]

This comment identifies a mistake in a paper by P. Bowman that claims that the total angular momentum of the ground state of atomic hydrogen is 1.Comment: 2 pp. To be published in Am. J. Phy

Energetics and efficiency of a molecular motor model

The energetics and efficiency of a linear molecular motor model proposed by Mogilner et al. (Phys. Lett. 237, 297 (1998)) is analyzed from an analytical point of view. The model which is based on protein friction with a track is described by coupled Langevin equations for the motion in combination with coupled master equations for the ATP hydrolysis. Here the energetics and efficiency of the motor is addressed using a many body scheme with focus on the efficiency at maximum power (EMP). It is found that the EMP is reduced from about 10 pct in a heuristic description of the motor to about 1 per mille when incorporating the full motor dynamics, owing to the strong dissipation associated with the motor action.Comment: 23 pages, 6 figures, final version, appeared in J. Stat. Mech. P12001 (2013

Bound particle coupled to two thermostats

We consider a harmonically bound Brownian particle coupled to two distinct heat reservoirs at different temperatures. We show that the presence of a harmonic trap does not change the large deviation function from the case of a free Brownian particle discussed by Derrida and Brunet and Visco. Likewise, the Gallavotti-Cohen fluctuation theorem related to the entropy production at the heat sources remains in force. We support the analytical results with numerical simulations

Tetracycline Actions Relevant to Rosacea Treatment

Until today, the pathogenesis of rosacea is not known in detail. Yet in recent years evidence has been accumulating that rosacea with its common symptoms such as inflammatory lesions, erythema, telangiectasia, phymatous changes, and ocular symptoms is of inflammatory nature. Tetracycline derivatives like doxycycline successfully used in the treatment of skin diseases like acne and rosacea seem to inhibit different inflammatory pathways involved in the pathogenesis by various modes of action. Although data for skin diseases are relatively scanty, the following modes of action of tetracyclines seem to be most relevant for an effective treatment of acne and rosacea: inhibition of matrix metalloproteinases, downmodulation of cytokines, inhibition of cell movement and proliferation, inhibition of granuloma formation, inhibition of reactive oxygen species, nitric oxide, and angiogenesis, whereas inhibition of phospholipase A2 seems to be of lower importance. The role of the saprophytic mite Demodex folliculorum remains to be clarified. Additional studies are necessary to further elucidate how tetracyclines work in rosacea treatment. Copyright (C) 2009 S. Karger AG, Base