A Role of DNA Methylation within the CYP17A1 Gene in the Association of Genetic and Environmental Risk Factors with Stress-Related Manifestations of Schizophrenia

As genetic and environmental influences on schizophrenia might converge on DNA methylation (DNAm) within loci which are both associated with the disease and implicated in response to environmental stress, we examined whether DNAm within CYP17A1, a hypothalamus–pituitary–adrenal axis gene which is situated within the schizophrenia risk locus 10q24.32, would mediate genetic and environmental effects on stress-related schizophrenia symptoms. DNAm within an exonic–intronic fragment of CYP17A1 was assessed in the blood of 66 schizophrenia patients and 63 controls using single-molecule real-time bisulfite sequencing. Additionally, the VNTR polymorphism of the AS3MT gene, a plausible causal variant within the 10q24.32 locus, was genotyped in extended patient and control samples (n = 700). The effects of local haplotype, VNTR and a polyenviromic risk score (PERS) on DNAm, episodic verbal memory, executive functions, depression, and suicidality of patients were assessed. Haplotype and PERS differentially influenced DNAm at four variably methylated sites identified within the fragment, with stochastic, additive, and allele-specific effects being found. An allele-specific DNAm at CpG-SNP rs3781286 mediated the relationship between the local haplotype and verbal fluency. Our findings do not confirm that the interrogated DNA fragment is a place where genetic and environmental risk factors converge to influence schizophrenia symptoms through DNAm.     

Numerical modelling of natural water colour: Implications for remote sensing and limnological studies

Based on suggested earlier optical models of Lakes Ontario and Ladoga, numerical modelling experiments have been carried out to the effect of revealing the responsiveness of chromaticity coordinates (x, y, z), dominant wavelength (lambda dom) and associated spectral purity (p) to the abundance in water of optically active components (OAC), i.e., phytoplankton (chl), suspended minerals (sm) and dissolved organic carbon (doc). It has been shown that highly turbid waters (i.e., waters with high chl and sm concentrations) with low content of doc display colour varying from green to brownish. High turbidity or large doc concentration invariably is characteristic of waters with brown colour. With growing OAC content in water, the chromaticity coordinates and, consequently, the dominant wavelength lambda dom tend asymptotically to respective limit values that seem to be intrinsically characteristic of natural waters. It is also shown that the colour purity p asymptotically tends to values of about 35-45 per cent (with the only exception for waters containing exclusively chl and this in small quantities (0.5mu gl-1)) when concentrations of one or more OAC are over 10 (in respective concentration units). These findings clearly indicate that neither panchromatic nor two-channel ratio images could be meaningful for an unambiguous inference of water quality parameters. Furthermore, the correspondence between water colour physical characteristics (i.e., x, y, z, lambda dom and p) and water colour scales traditionally used in limnology is established.     

Review article - Remote sensing and global tropospheric ozone observed dynamics

The development of remote sensing techniques to obtain measurements of ozone and its precursors from the Earth's surface to the tropopause is considered, to present a review on the current achievements in measuring tropospheric ozone variability. Special attention is given to the surface ozone concentration observations, to the production and destruction mechanisms of ozone in both the atmospheric boundary layer and the free troposphere, and finally to ozone exchange through the tropopause.     

Interaction of a “gas-liquid” phase interface with a mineral particle

The interaction of a mineral particle with the surface of a bubble during froth flotation is studied. Results are presented from an analysis of the equation of motion of a particle fixed at the interface. It is shown that preservation of the “particle-bubble” aggregate depends on the frequencies of natural vibrations of the bubble and the particle and the properties of the surface of the mineral. Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirks. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 115–120, July–August, 1999.     

Measuring the nuclear charge of fission fragments using a large ionization chamber—part of the double-arm time-of-flight spectrometer

Identification of decay products is a relevant task in studying rare collinear decays of low excited heavy nuclei. A technique for measuring the nuclear charge of decay products detected by a wide-aperture ionization chamber—a part of the double-arm time-of-flight spectrometer—is described. Two versions of nuclear charge calibration using data of the reaction ²³⁵U(n _th, f) have been developed to determine the charge of the decay products. Testing with simulation data shows that the use of charge parameterization based on the Bohr-Willer empirical equation in the calibration procedure makes it possible to determine the nuclear charge of the fission fragments over a wide energy range. The charges of light ions from He to C, predicted on the basis of this approach, appear to be overestimated by two charge units.     

New evidence for ozone depletion over Athens,Greece

The seasonal total column ozone (TOZ) trends derived from satellite and ground-based instrumentation between June 1991-July 1999 at Athens, Greece, appear to be opposite to those of the period November 1978-May 1991. In the post-Pinatubo period large negative trends in TOZ during summertime combined with the large positive trends in TOZ during fall-winter period result in a decrease of the annual peak-to-trough differences from those of the pre-Pinatubo period.     

Effect of thermal treatment on acoustic characteristics of materials

Measured acoustic characteristics of some structural materials subjected to different types of thermal treatment are presented. Averaging of the ultrasonic waves’ phase when a probe’s dimensions and measurement base increase is observed.