Physical–chemical properties of plasma membrane and function of erythrocytes of cosmonauts after long-term space flight

We studied microfluidity and selective ion permeability of plasma membranes and O₂-binding properties of erythrocytes of cosmonauts during early rehabilitation after a long-term space flight (LTSF). Microfluidity of plasma membranes in surface regions was found to undergo a reversible decrease during 13–15 days following LTSF, which was accompanied by a reversible increase in relative cholesterol content. Cosmonauts’ erythrocytes revealed an increased activity of Na/H-exchanger and K_Ca-channel as well as a decrease in number of discocytes and increase in number of echinocytes, stomatocytes and knizocytes. Total hemoglobin content as well as oxyhemoglobin content were lowered after the LTSF, while the affinity of hemoglobin to O₂ was advanced. It is suggested that the changes in Hb properties, microfluidity and selective permeability of plasma membranes following the elevated cholesterol content in the membranes can decrease tissue supply with O₂.     

First Results of the THEMIS Search Coil Magnetometers

We present the first data from the THEMIS Search Coil Magnetometers (SCM), taken between March and June 2007 while the THEMIS constellation apogee moved from the duskside toward the dawnside. Data reduction, especially the SCM calibration method and spurious noise reduction process, is described. The signatures of magnetic fluctuations in key magnetospheric regions such as the bow shock, the magnetopause and the magnetotail during a substorm, are described. We also discuss the role that magnetic fluctuations could play in plasma transport, acceleration and heating.     

The electron formations under the radiation belts at L-shells 1.2–1.9

We continue to analyze the distribution of electron fluxes with energy 30–500 keV under the radiation belts at low and middle latitudes (L = 1.2–1.9) using experimental data obtained onboard ACTIVE satellite. Special attention is given to altitudinal distribution of electron fluxes and detailed analysis of these electron formations. We observe three main regions of electron flux registration that seem to exist constantly under the radiation belts. These regions are: magneto-conjugated to SAA region (in the north hemisphere), local zone of low intense electron flux accumulation to the west of SAA, and extensive region in the north hemisphere to the east. The analysis of experimental data obtained from ACTIVE satellite (orbit height 500–2500 km) shows that electron fluxes are registered in the wide altitude range up to 1100 km. It is shown that these formations have complicated initial structure with two regions of flux maximums: at L = 1.3 and L = 1.6–1.8. We compare particle data with low frequency (LF) data (ARIEL-4 satellite) and high frequency (HF) data (CORONAS-I satellite). Also we discuss the possible mechanisms of the appearance of these formations under the radiation belts.     

Impact of helio-and geophysical disturbances on thermobaric and climatic characteristics of the Earth’s troposphere

We present the mechanism and the concept of a model of the solar activity impact on thermobaric and climatic characteristics of the troposphere. Both are based on the idea of parametric action. The results of analysis are presented concerning specific features and regularities of changes in temperature regime of the troposphere in the period of variable helio-and geophysical activity, as well as long-term variations of temperature and heat content of the troposphere. The influence of changes in circulation in the atmosphere and ocean on processes in the system atmosphere-ocean-cryosphere is considered: thermohaline circulation of the oceans and energy exchange between the atmosphere and ocean. The revealed regularities find their complete explanation within the context of a model and mechanism of solar activity impact on climatic characteristics of the troposphere that were suggested previously by the authors.     

The astrobiology primer: an outline of general knowledge--version 1, 2006

The Astrobiology Primer has been created as a reference tool for those who are interested in the interdisciplinary field of astrobiology. The field incorporates many diverse research endeavors, but it is our hope that this slim volume will present the reader with all he or she needs to know to become involved and to understand, at least at a fundamental level, the state of the art. Each section includes a brief overview of a topic and a short list of readable and important literature for those interested in deeper knowledge. Because of the great diversity of material, each section was written by a different author with a different expertise. Contributors, authors, and editors are listed at the beginning, along with a list of those chapters and sections for which they were responsible. We are deeply indebted to the NASA Astrobiology Institute (NAI), in particular to Estelle Dodson, David Morrison, Ed Goolish, Krisstina Wilmoth, and Rose Grymes for their continued enthusiasm and support. The Primer came about in large part because of NAI support for graduate student research, collaboration, and inclusion as well as direct funding. We have entitled the Primer version 1 in hope that it will be only the first in a series, whose future volumes will be produced every 3-5 years. This way we can insure that the Primer keeps up with the current state of research. We hope that it will be a great resource for anyone trying to stay abreast of an ever-changing field.     

Orientation of Sharp Fronts of the Solar Wind Plasma

Based on simultaneous observations performed by several spacecraft, we evaluate the orientation of sharp (with a duration of a few minutes) and large (tens and hundreds percent of the mean value) fronts of the solar wind plasma (changes in the ion flux and ram pressure). The orientation of the fronts is determined with respect to the Sun–Earth line and to two planes in space for several tens of the largest (in amplitude) changes of the ion flux. A considerable fraction of these fronts (about 50%) has an inclination to the plane perpendicular to the Sun–Earth line that exceeds 30°.     

A Search for Possible Mesolensing of Cosmic Gamma-Ray Bursts: II. Double and Triple Bursts in the BATSE Catalog

The paper is devoted to searching for a possible phenomenon of the gravitational lensing of cosmic gamma-ray bursts on celestial bodies of a globular cluster type (mesolensing). If this phenomenon takes place, gamma-ray bursts should have light curves with two or three similar components whose spectra are identical. These components are separated in time by a few seconds. Using a statistical method developed for comparing the components, we have found in the BATSE catalog 11 candidates of gamma-ray bursts with mesolensing for the entire time of operation of the Compton Gamma-Ray Observatory (1991–2000). Two of these 11 gamma-ray bursts have light curves with three components. The possibility of gravitational mesolensing of these gamma-ray bursts on the King's type bodies is investigated.     

MHD Simulations of the Dynamics of Sharp Disturbances of the Interplanetary Medium and Comparison with Spacecraft Observations

One-dimensional MHD simulations of solitary sharp and strong disturbances (impulses) of the interplanetary magnetic field and plasma of the homogeneous solar wind were performed. The characteristics of a disturbance of this type, recorded onboard the WIND spacecraft (SC) rather far from the Earth, were taken as initial conditions. The results of numerical experiments simulating the evolution of this disturbance in the moving interplanetary plasma, whose parameters correspond to observations of the WIND and INTERBALL-1 SC, show the efficiency of the computer code developed with the special purpose of investigating low-frequency wave events in the space environment. The calculated characteristics of the impulse resulting from the evolution are in good agreement with parameters of the disturbance recorded by the INTERBALL-1 SC closer to the Earth. In particular, the impulse expands due to imbalance of thermal and magnetic pressures, but keeps its abrupt boundaries. It was demonstrated that stable plasma objects, corresponding to stationary MHD solutions, could really exist in the solar wind plasma for a long time.     

深空通信文件传输协议的交织技术研究

引入喷泉编码技术应用于深空通信,对CCSDS文件传输协议进行改进,提出了一种针对深空环境长时延、高误码率、丢包率大和链路易中断等特点的基于数据包交织的文件传输协议。根据深空通信文件传输的业务需要设计了两种不同的级别概率分布,接收端只需要接收到一定数量的数据包,就能够恢复出整个原始信息,无需或需要很少反馈确认信息。仿真验证交织技术能够简化传输协议,减少文件传输时延,增大系统的吞吐量并保证通信的有效性。
     

Conditions for exciting the maximal gas vibration amplitude in a combustion chamber of the Helmholtz resonator type

In this paper, we present the results of calculating conditions for gas vibration excitement, sound pressure frequency and level as a function of mixture composition, geometric burner parameters and the resonator throat with constant capacity. We estimate in quantity the parameters influencing a vibration combustion process in the Helmholtz resonator with the inlet multichannel burner which result in the maximum possible gas vibration amplitude value.