An instability criterion for a finite amplitude localized disturbance in a shear flow of electrically conducting fluids

The stability of shear flows of electrically conducting fluids, with respect to finite amplitude three-dimensional localized disturbances is considered. The time evolution of the fluid impulse integral, characterizing such disturbances, for the case of low magnetic Reynolds number is obtained by integrating analytically the vorticity equation. Analysis of the resulted equation reveals a new instability criterion.Comment: 10 pages in LaTex, no figures, accepted in Phys. Fluid

SHIFTWORK AS ONE OF RISK FACTORS OF ARTERIAL HYPERTENSION AND METABOLIC DISORDERS

Background. Shiftwork is considered as one of risk factors of arterial hypertension (HT) and metabolic disorders. Aim. To study effects of different types of shift plan on HT and the metabolic disorders development. Material and Methods. 1091 men were included in the study. Patients were split into subgroups according to age (20–29, 30–39, 40–49, 50–59 years old) and shift plan (steady or shiftable work schedule). HT (blood pressure >130/85 mm Hg), abdominal obesity (waist circumference >94 cm), disorders of glucose metabolism were revealed. Results. HT prevalence in patients with shiftwork was significantly higher than that in employees with steady work schedule (34.4 vs 27.4%, respectively; р<0.01). In patients with shift and steady work schedule significant differences in abdominal obesity (69.2 vs. 19.3%, respectively; p<0.001) and glucose metabolism disorders rates (19.0 vs. 10.6%, respectively; p<0.001) were also found. Differences between groups in prevalence of hypercholesterolemia and metabolic disorders cluster were not significant. HT associated with metabolic disorders dominated among steady work patients aged 40-49 years (56.7%) in comparison with shiftable work patients (20.0%), p<0.01. Conclusion. Shiftwork may be considered as a risk factor of HT and metabolic disorders in males

Growing Scale-Free Networks with Tunable Clustering

We extend the standard scale-free network model to include a ``triad formation step''. We analyze the geometric properties of networks generated by this algorithm both analytically and by numerical calculations, and find that our model possesses the same characteristics as the standard scale-free networks like the power-law degree distribution and the small average geodesic length, but with the high-clustering at the same time. In our model, the clustering coefficient is also shown to be tunable simply by changing a control parameter - the average number of triad formation trials per time step.Comment: Accepted for publication in Phys. Rev.

Quantization of the Riemann Zeta-Function and Cosmology

Quantization of the Riemann zeta-function is proposed. We treat the Riemann zeta-function as a symbol of a pseudodifferential operator and study the corresponding classical and quantum field theories. This approach is motivated by the theory of p-adic strings and by recent works on stringy cosmological models. We show that the Lagrangian for the zeta-function field is equivalent to the sum of the Klein-Gordon Lagrangians with masses defined by the zeros of the Riemann zeta-function. Quantization of the mathematics of Fermat-Wiles and the Langlands program is indicated. The Beilinson conjectures on the values of L-functions of motives are interpreted as dealing with the cosmological constant problem. Possible cosmological applications of the zeta-function field theory are discussed.Comment: 14 pages, corrected typos, references and comments adde

Interlayer Registry Determines the Sliding Potential of Layered Metal Dichalcogenides: The case of 2H-MoS2

We provide a simple and intuitive explanation for the interlayer sliding energy landscape of metal dichalcogenides. Based on the recently introduced registry index (RI) concept, we define a purely geometrical parameter which quantifies the degree of interlayer commensurability in the layered phase of molybdenum disulphide (2HMoS2). A direct relation between the sliding energy landscape and the corresponding interlayer registry surface of 2H-MoS2 is discovered thus marking the registry index as a computationally efficient means for studying the tribology of complex nanoscale material interfaces in the wearless friction regime.Comment: 13 pages, 7 figure