30 research outputs found
Modeling of gamma-avalanche formation in the "optical" thick medium with 178Hf through the nuclear diffraction channel
The formation of Îł-avalanche in the medium with 178Hf isotope has modeled through the nuclear diffraction channel. The equation system describing the process under two-wave Bragg diffraction conditions has obtained. The numerical simulation for the "optical" thick medium has been made
Modeling of gamma-pulse propagation in the "optical" thick medium with inverted population of the nuclear levels of 178Hf isotope
The nuclear superfluorescence in the "optical" medium with 178Hf in propagation channel has been modeled. The general equations system describing the nuclear superfluorescence in the "optical" medium has obtained. The numerical simulation in the propagation channel in the "optical" thick medium with Hf has been made
The analytical and numerical approaches to the theory of the Moon's librations: Modern analysis and results
© 2017 COSPAR Observing physical librations of celestial bodies and the Moon represents one of the astronomical methods of remotely assessing the internal structure of a celestial body without conducting expensive space experiments. The paper contains a review of recent advances in studying the Moon's structure using various methods of obtaining and applying the lunar physical librations (LPhL) data. In this article LPhL simulation methods of assessing viscoelastic and dissipative properties of the lunar body and lunar core parameters, whose existence has been recently confirmed during the seismic data reprocessing of “Apollo” space mission, are described. Much attention is paid to physical interpretation of the free librations phenomenon and the methods for its determination. In the paper the practical application of the most accurate analytical LPhL tables (Rambaux and Williams, 2011) is discussed. The tables were built on the basis of complex analytical processing of the residual differences obtained when comparing long-term series of laser observations with the numerical ephemeris DE421. In the paper an efficiency analysis of two approaches to LPhL theory is conducted: the numerical and the analytical ones. It has been shown that in lunar investigation both approaches complement each other in various aspects: the numerical approach provides high accuracy of the theory, which is required for the proper processing of modern observations, the analytical approach allows to comprehend the essence of the phenomena in the lunar rotation, predict and interpret new effects in the observations of lunar body and lunar core parameters
Resonant nonlinear magneto-optical effects in atoms
In this article, we review the history, current status, physical mechanisms,
experimental methods, and applications of nonlinear magneto-optical effects in
atomic vapors. We begin by describing the pioneering work of Macaluso and
Corbino over a century ago on linear magneto-optical effects (in which the
properties of the medium do not depend on the light power) in the vicinity of
atomic resonances, and contrast these effects with various nonlinear
magneto-optical phenomena that have been studied both theoretically and
experimentally since the late 1960s. In recent years, the field of nonlinear
magneto-optics has experienced a revival of interest that has led to a number
of developments, including the observation of ultra-narrow (1-Hz)
magneto-optical resonances, applications in sensitive magnetometry, nonlinear
magneto-optical tomography, and the possibility of a search for parity- and
time-reversal-invariance violation in atoms.Comment: 51 pages, 23 figures, to appear in Rev. Mod. Phys. in Oct. 2002,
Figure added, typos corrected, text edited for clarit
Epigenetic mechanisms in virus-induced tumorigenesis
About 15–20% of human cancers worldwide have viral etiology. Emerging data clearly indicate that several human DNA and RNA viruses, such as human papillomavirus, Epstein–Barr virus, Kaposi’s sarcoma-associated herpesvirus, hepatitis B virus, hepatitis C virus, and human T-cell lymphotropic virus, contribute to cancer development. Human tumor-associated viruses have evolved multiple molecular mechanisms to disrupt specific cellular pathways to facilitate aberrant replication. Although oncogenic viruses belong to different families, their strategies in human cancer development show many similarities and involve viral-encoded oncoproteins targeting the key cellular proteins that regulate cell growth. Recent studies show that virus and host interactions also occur at the epigenetic level. In this review, we summarize the published information related to the interactions between viral proteins and epigenetic machinery which lead to alterations in the epigenetic landscape of the cell contributing to carcinogenesis
Chronic Viral Infection and Primary Central Nervous System Malignancy
Primary central nervous system (CNS) tumors cause significant morbidity and mortality in both adults and children. While some of the genetic and molecular mechanisms of neuro-oncogenesis are known, much less is known about possible epigenetic contributions to disease pathophysiology. Over the last several decades, chronic viral infections have been associated with a number of human malignancies. In primary CNS malignancies, two families of viruses, namely polyomavirus and herpesvirus, have been detected with varied frequencies in a number of pediatric and adult histological tumor subtypes. However, establishing a link between chronic viral infection and primary CNS malignancy has been an area of considerable controversy, due in part to variations in detection frequencies and methodologies used among researchers. Since a latent viral neurotropism can be seen with a variety of viruses and a widespread seropositivity exists among the population, it has been difficult to establish an association between viral infection and CNS malignancy based on epidemiology alone. While direct evidence of a role of viruses in neuro-oncogenesis in humans is lacking, a more plausible hypothesis of neuro-oncomodulation has been proposed. The overall goals of this review are to summarize the many human investigations that have studied viral infection in primary CNS tumors, discuss potential neuro-oncomodulatory mechanisms of viral-associated CNS disease and propose future research directions to establish a more firm association between chronic viral infections and primary CNS malignancies
Modeling of gamma-avalanche formation in the "optical" thick medium with 178Hf through the nuclear diffraction channel
The formation of Îł-avalanche in the medium with 178Hf isotope has modeled through the nuclear diffraction channel. The equation system describing the process under two-wave Bragg diffraction conditions has obtained. The numerical simulation for the "optical" thick medium has been made
Modeling of gamma-avalanche formation in the "optical" thick medium with 178Hf through the nuclear diffraction channel
The formation of Îł-avalanche in the medium with 178Hf isotope has modeled through the nuclear diffraction channel. The equation system describing the process under two-wave Bragg diffraction conditions has obtained. The numerical simulation for the "optical" thick medium has been made
Modeling of gamma-avalanche formation in the "optical" thick medium with 178Hf through the nuclear diffraction channel
The formation of Îł-avalanche in the medium with 178Hf isotope has modeled through the nuclear diffraction channel. The equation system describing the process under two-wave Bragg diffraction conditions has obtained. The numerical simulation for the "optical" thick medium has been made
Modeling of gamma-pulse propagation in the "optical" thick medium with inverted population of the nuclear levels of 178Hf isotope
The nuclear superfluorescence in the "optical" medium with 178Hf in propagation channel has been modeled. The general equations system describing the nuclear superfluorescence in the "optical" medium has obtained. The numerical simulation in the propagation channel in the "optical" thick medium with Hf has been made