Hidden instabilities in the Ti:sapphire Kerr lens mode-locked laser

It is experimentally shown that pulse-to-pulse instabilities in the output of Kerr lens mode-locked Ti:sapphire lasers are usual and that they can affect some of the pulse variables (e.g., the spot size) and not others (e.g., pulse duration and energy). These instabilities are not detectable in the averaged signals (such as the autocorrelation of the pulse) that are customarily used for controlling the laser. But, if they are present but are disregarded, these instabilities have undesirable consequences in almost any application. A simple way to detect and eliminate the instabilities is described.     

Low Dimension Dynamics in the EPRB Experiment with Random Variable Analyzers

The Einstein–Podolsky–Rosen–Bohm (EPRB) experiment performed with random variable and spatially separated analyzers is a milestone test in the controversy between Objective Local Theories (OLT) and Quantum Mechanics (QM). Only a few OLT are still possible. Some of the surviving OLT (specifically, the so called non-ergodic theories) would be undetectable in the averaged statistical values, but they may leave their trace in the time dynamics. For, while QM predicts random processes, the OLT of this kind predict the existence of regularities that may be revealed as a low dimensional object in the phase space. We perform a numerical analysis of the time-resolved data recorded in that experiment to unveil any hypothetical low dimensional dynamics that may be present. We find no consistent indication of such dynamics except for one data file, the longest of all in the real time. The possible causes of these dynamics are discussed.      

Extended Cylindrical Low-Pressure Arc Discharge Plasma Emitter for Generation of a Radially Diverging Electron Beam

Russian Physics Journal - The paper presents the results of studies of processes of generation of a beam-plasma formation in an extended cylindrical hollow mesh anode with a diameter of 115 mm and...     

A reference-gene-based quantitative PCR method as a tool to determine <Emphasis Type="Italic">Fusarium</Emphasis> resistance in wheat

In recent years, plant breeders made great progress in breeding Fusarium-tolerant wheat lines. However, total resistance to this genus of plant pathogenic fungi has not yet been achieved as the resistance genes are located on several distinct genetic regions. Visual scoring of disease symptoms in combination with the analysis of mycotoxins is commonly applied to assess the tolerance of new lines. Both approaches are indirect methods and do not mandatorily determine the accumulated fungal biomass. Quantitative PCR is a useful tool to assess fungal biomass based on the abundance of organism-specific DNA. The aim of this study was the development of a quantitative PCR assay for trichothecene-producing Fusarium species and to adapt this method for resistance assessment of wheat lines artificially infected with Fusarium graminearum and Fusarium culmorum. Several DNA-extraction methods for wheat samples were evaluated and optimized for downstream real-time PCR analysis and furthermore, a new reference-gene-based approach for more accurate quantification of Fusarium biomass in cereals is presented. The co-determination of a plant gene was used to compensate for unequal DNA-extraction efficiencies.     

Pulsed Non-Self-Sustained Arc Discharge in Extended Hollow Anode

Russian Physics Journal - The paper investigates physical properties of a pulsed arc discharge of low (≈1 Pa) pressure created in argon by a plasma source with the thermionic and hollow...     

Real polarizers and faster than light signaling

An imperfection of real polarizers (as opposite to ideal ones) seems to provide a method for faster than light signaling, threatening the structural stability of quantum field theory. The cause of the unphysical result is explained, and the problem of structural stability is solved.     

Extreme events in the Ti:sapphire laser

We report experimental and theoretical evidence of the existence of extreme value events in the form of scarce and randomly emerging giant pulses in the femtosecond (self-pulsing or Kerr-lens mode-locked) Ti:sapphire laser. This laser displays complex dynamical behavior, including deterministic chaos, in two different regimes. The extreme value pulses are observed in the chaotic state of only one of these two regimes. The observations agree with the predictions of a well-tested theoretical model that does not include noise or self-Q-switching into its framework. This implies that, in this laser, the extreme effects have a nontrivial dynamical origin. The Ti:sapphire laser is hence revealed as a new and convenient system for the study of these effects.     

Formation of Alloyed Layers with Improved Mechanical Properties on the MA-2 Magnesium Alloy Surface by the Method of Electron-Ion-Plasma Modification

Russian Physics Journal - The MA-2 magnesium alloy surface has been alloyed with aluminum by the method of combined electron-ionplasma exposure which consists in deposition of a thin (1 μm)...     

Laser (two-quantum) photolysis of polynucleotides and nucleoproteins: quantitative processing of results

The paper offers and substantiates a technique for quantitative processing of the photochemical reactions in polynucleotides, nucleoproteins and their components caused by the action of powerful ultraviolet laser pulse radiation.