Delocalization of Longitudinal Acoustic-Like Excitations in DNA Due to Structural Effects

Terahertz-frequency phonon-like modes in DNA have been widely studied both experimentally and theoretically in recent years. However, current theoretical models turn out to fail to reproduce some basic properties of these modes. Using a generalized hydrodynamics approach and the results of inelastic X-ray scattering measurements, we propose a model to describe structural effects due to wavenumber dependence of the static structure factor in the dynamics of longitudinal acoustic-like excitations in DNA. Our analysis qualitatively suggests that on a length scale corresponding to a wavenumber region between the positions of the maximum and the minimum of the dispersion relation for the excitation frequency, structural effects may induce a tendency of delocalization of the dynamics. This proposal is consistent with the recent experimental observations of delocalized terahertz-frequency DNA phonon-like modes that seem to be relevant to biological function.

     

DNA vaccine containing the mycobacterial hsp65 gene prevented insulitis in MLD-STZ diabetes

Background  

Our group previously demonstrated that a DNA plasmid encoding the mycobacterial 65-kDa heat shock protein (DNA-HSP65) displayed prophylactic and therapeutic effect in a mice model for tuberculosis. This protection was attributed to induction of a strong cellular immunity against HSP65. As specific immunity to HSP60 family has been detected in arthritis, multiple sclerosis and diabetes, the vaccination procedure with DNA-HSP65 could induce a cross-reactive immune response that could trigger or worsen these autoimmune diseases.     

Measurements of integrated muon intensity at large zenith angles

Data from the DECOR coordinate detector on the integrated intensity of muons that have a threshold energy of 1.2 to 2 GeV are analyzed over the zenith-angle interval 60°–90°. Experimental results in these intervals of zenith angles and threshold energies were obtained for the first time. In the interval θ ≤ 80°, the integrated intensity at E _min = 1.5 GeV as a function of the cosine of the zenith angle is described by a power-law function characterized by an exponent value of n = 1.884 ± 0.005, which is close to the value obtained in earlier experiments.     

Wave attenuation model for dephasing and measurement of conditional times

Inelastic scattering induces dephasing in mesoscopic systems. An analysis of previous models to simulate inelastic scattering in such systems is presented and a relatively new model based on wave attenuation is introduced. The problem of Aharonov-Bohm (AB) oscillations in conductance of a mesoscopic ring is studied. We show that the conductance is symmetric under flux reversal and the visibility of AB oscillations decays to zero as a function of the incoherence parameter, signaling dephasing. Further the wave attenuation model is applied to a fundamental problem in quantum mechanics, that of the conditional (reflection/transmission) times spent in a given region of space by a quantum particle before scattering off from that region.     

Representation of the β-function and anomalous dimensions by nonsingular integrals: Proof of the main relation

A method for calculating the β-function and anomalous dimensions, convenient for numerical calculations in the ?-expansion framework, was previously proposed, and the relation underlying the method was verified up to the four-loop approximation. We prove this relation in all orders of the perturbation theory.     

Evaluated benchmark experiments at critical assemblies simulating features of an HTHR at the ASTRA facility

The design of the ASTRA facility and critical assemblies that simulate physics features of modular high-temperature reactors (HTHR-Ms) with a graphite moderator and reflectors loaded with fuel particles having multilayer ceramic coatings is described in detail. Geometrical dimensions of the main elements and regions of the critical assemblies, composition of the materials used, and experimental results for various configurations of the critical assemblies are presented. A detailed computational benchmark model allowing for the structural and compositional features of the critical assembly configurations in question is developed on the basis of all the above data. The results are to be used for verification of the neutronics codes used for calculations of high-temperature helium-cooled reactors.     

HYDRA hydroacoustic antenna in the NEVOD experimental complex

The main characteristics of the HYDRA hydroacoustic antenna intended for the detection of signals generated by cores of extensive air showers in a water Cherenkov detector involved in the NEVOD experimental complex are considered. Primary attention is focused on the calibration of antenna sensors and on the selection of an optimum trigger that ensures an effective detection of acoustic signals generated by cores of extensive air showers in the water volume of the Cherenkov detector.     

Investigation of cosmic rays above the knee by means of muon bundles detected in a wide range of zenith angles

The results of investigation of muon bundles at the Earth’s surface in a wide range of zenith angles on the basis of the new phenomenological characteristic of extensive air showers—spectra of local muon density—have been investigated. Features of the local-density spectra are considered within a simple analytical model. The expected distributions of muon density in a wide range of zenith angles and primary energies, calculated on the basis of the CORSIKA code, are compared with the experimental data.