Chromatin from sperm of Bivalvia molluscs Specific features of nucleosomal organization

AbstractIn chromatin from the sperm of two Bivalvia molluscs a highly basic low molecular mass sperm-specific protein (S-protein) has been found in addition to the full complement of histones. It is shown that sperm chromatin preserves nucleosomal organization, some parameters of which are specific: (i) DNase I cuts DNA within the sperm nuclei with dinucleosomal periodicity; (ii) linker DNA of the nucleosome is significantly elongated. The S-protein is shown to be located on the linker DNA

Steady-state spin densities and currents

This article reviews steady-state spin densities and spin currents in materials with strong spin-orbit interactions. These phenomena are intimately related to spin precession due to spin-orbit coupling which has no equivalent in the steady state of charge distributions. The focus will be initially on effects originating from the band structure. In this case spin densities arise in an electric field because a component of each spin is conserved during precession. Spin currents arise because a component of each spin is continually precessing. These two phenomena are due to independent contributions to the steady-state density matrix, and scattering between the conserved and precessing spin distributions has important consequences for spin dynamics and spin-related effects in general. In the latter part of the article extrinsic effects such as skew scattering and side jump will be discussed, and it will be shown that these effects are also modified considerably by spin precession. Theoretical and experimental progress in all areas will be reviewed

Experience of machine vision application in optical NDT systems

Two automated optical inspection systems – for defects detection of in the ligature under UV irradiation and for non-destructive testing of pipeline inner surface – were described. The features of constructions and algorithms of the developed software with using the computer vision techniques were presented. Engineered systems were introduced successfully into commercial operation.Описаны две автоматизированные системы оптического контроля – для обнаружения дефектов в лигатуре под ультрафиолетовым облучением и для внутритрубной дефектоскопии поверхности. Представлены особенности конструкций и алгоритмы функционирования разработанного программного обеспечения с использованием методов технического зрения. Сконструированные системы успешно сданы в промышленную эксплуатацию

A non-linear optimal estimation inverse method for radio occultation measurements of temperature, humidity and surface pressure

An optimal estimation inverse method is presented which can be used to retrieve simultaneously vertical profiles of temperature and specific humidity, in addition to surface pressure, from satellite-to-satellite radio occultation observations of the Earth's atmosphere. The method is a non-linear, maximum {\it a posteriori} technique which can accommodate most aspects of the real radio occultation problem and is found to be stable and to converge rapidly in most cases. The optimal estimation inverse method has two distinct advantages over the analytic inverse method in that it accounts for some of the effects of horizontal gradients and is able to retrieve optimally temperature and humidity simultaneously from the observations. It is also able to account for observation noise and other sources of error. Combined, these advantages ensure a realistic retrieval of atmospheric quantities. A complete error analysis emerges naturally from the optimal estimation theory, allowing a full characterisation of the solution. Using this analysis a quality control scheme is implemented which allows anomalous retrieval conditions to be recognised and removed, thus preventing gross retrieval errors. The inverse method presented in this paper has been implemented for bending angle measurements derived from GPS/MET radio occultation observations of the Earth. Preliminary results from simulated data suggest that these observations have the potential to improve NWP model analyses significantly throughout their vertical range.Comment: 18 (jgr journal) pages, 7 figure

Magneto-gyrotropic effects in semiconductor quantum wells (review)

Magneto-gyrotropic photogalvanic effects in quantum wells are reviewed. We discuss experimental data, results of phenomenological analysis and microscopic models of these effects. The current flow is driven by spin-dependent scattering in low-dimensional structures gyrotropic media resulted in asymmetry of photoexcitation and relaxation processes. Several applications of the effects are also considered.Comment: 28 pages, 13 figure