Changes of cell-vascular complex in zones of adaptive remodeling of the bone tissue under microgravity conditions.

We examined the peculiarities of the structure of the blood-vascular bed and perivascular cells in zones of osteogenesis in the epiphyses and metaphises of femoral bones of rats, flown aboard the US laboratory SLS-2 for two weeks by electron microscopy and histochemistry. In zones of bone remodeling, there was a tendency for a reduction of sinusoid capillary specific volume. Endotheliocytes preserve the typical structure. In the population of perivascular cells, we discovered differentiating osteogenic cells that contained alkaline phosphomonoesterase as well as cells that don't contain this enzyme and differentiate into fibroblasts. The fibroblasts genesis in zones of adaptive remodeling of spongy bones leads to a further development of fibrous tissue that is not subject to mineralization.     

Overview on experience to date on human exposure to space radiations.

The human exposure in space depends on the three factors: the flight trajectory, its date and duration and the cyclogram of the cosmonaut's activities. In the near-Earth orbits the daily dose varies within the limits of (1.5-5.0) 10(-4) Gy day-1 and greatly increases if the altitude increases. The mean daily quality factor is 1.6-2.0. Strong solar proton events in the orbits with the inclination of < 52 degrees result in the dose rate increase up to 2-3 cGy day-1. On the surface of the orbital spacecrafts the daily dose reaches 2 Gy. The neutron dose depends on the shielding mass distribution varying within the limits of 6%-30% of the charged particles dose. In deep space the dose is mainly formed by the galactic and solar cosmic rays(GCR,SCR). Behind the shielding of 2-3 g cm-2 Al the GCR dose varies in the range of (20-30) 10(-5) Gy day-1. The SCR dose can reach hundreds of cSv.     

Kinematics of Saturn's spokes

Voyager 2 images of Saturn's rings have been analyzed for spoke activity. More than 80 and 40 different spokes have been measured at the morning and at the evening ansa, respectively. Higher rate of spoke formation has been found at 145° ± 15° SLS and at 305° ± 15° SLS which persisted for at least 3 Saturn revolutions. Higher spoke activity (formation and growth in width) by more than a factor 3 has been observed over the nightside hemisphere of Saturn than over the dayside hemisphere. The age distribution (i.e. time from radial formation until observation, assuming Keplerian shear) of the leading (old) edges of spokes has its maximum at ～ 9,000 s and ～ 6,000 s for spokes observed at the morning ansa and at the evening ansa, respectively. The highest spoke age observed is ～ 20,000 s. The age distribution of the trailing (young) edges of spokes peaks at < 2,000 s at both ansae but has its mean at ～ 4,500 s and ～ 3,500 s, respectively. On the average the observed spokes grew in width for ～ 4,500 s at the morning ansa and for ～ 2,500 s at the evening ansa. The maximum time of growth in width was ～ 12,000 s.     

On statistical relationship of solar, geomagnetic and human activities.

Data of galactic cosmic rays, solar and geomagnetic activities and solar wind parameters on the one side and car accident events (CAE) in Poland on the other have been analyzed in order to reveal the statistical relationships among them for the period of 1990-2001. Cross correlation and cross spectrum of the galactic cosmic ray intensity, the solar wind (SW) velocity, Kp index of geomagnetic activity and CAE in Poland have been carried out. It is shown that in some epochs of the above-mentioned period there is found a reliable relationship between CAE and solar and geomagnetic activities parameters in the range of the different periodicities, especially, 7 days. The periodicity of 7 days revealed in the data of the CAE has the maximum on Friday without any exception for the minimum and maximum epochs of solar activity. However, the periodicity of 7 days is reliably revealed in other parameters characterizing galactic cosmic rays, SW, solar and geomagnetic activities, especially for the minimum epoch of solar activity. The periodicity of 3.5 days found in the series of CAE data more or less can be completely ascribed to the social effects, while the periodicity of 7 days can be ascribed to the social effect or/to the processes on the Sun, in the interplanetary space and in the Earth's magnetosphere and atmosphere.     

The effects of extended clinorotation on potato minituber formation and structure.

Formation and structure of potato minitubers grown aseptically for 30 days on a horizontal clinostat and in stationary control have been studied by light and electron microscopy. It was demonstrated that the number of plants that formed minitubers, their size and fresh weight, was higher when clino-rotated than in the stationary control. It was revealed that the amount of amyloplasts in parenchyma cell sections was doubled in minitubers formed under clino-rotation. Other factors (shape of minitubers and size of reserve parenchyma cells) did not differ from the stationary control. The changes in amyloplast ultrastructure suggest accelerated cell maturity of potato reserve parenchyma in extended clino-rotation.     

Problems and conception of ensuring radiation safety during Mars missions.

The Mars mission differs from near-Earth manned space flights by radiation environment and duration. The importance of effective using the weight of the spacecraft increases greatly because all the necessary things for the mission must be included in its starting weight. For this reason the development of optimal systems of radiation safety ensuring (RSES) acquires especial importance. It is the result of sharp change of radiation environment in the interplanetary space as compared to the one in the near-Earth orbits and significant increase of the interplanetary flight duration. The demand of a harder limitation of unfavorable factors effects should lead to radiation safety (RS) standards hardening. The main principles of ensuring the RS of the Mars mission (optimizing, radiation risk, ALARA) and the conception of RSES, developed on the basis of the described approach and the experience obtained during orbital flights are presented in the report. The problems that can impede the ensuring of the crew members' RS are also given here.     

Anti-aircraft artillery simulator

Air defense systems protect land and maritime resources from air attack. Depending on the regional characteristics and type of conflicting forces, air defense threats vary considerably. In regional conflicts, where forces with similar capabilities are involved and no air-superiority can be achieved, the role of air defense systems becomes critical. In combat terrains containing mountains (in mainland or in small islands), the man-operated or computer-controlled (using passive sensors) anti-aircraft artillery can be highly effective. The simulator presented in this work aims to exploit the capabilities provided by current commercial-off-the-shelf (COTS) communication and multimedia technologies for providing a training environment that improves the personnel capability for effective use of man-controlled anti-aircraft weapons.     

Analysis of cytogenetic effects of the secondary radiation resulting from 70 GeV protons of Chinese hamster cells.

The cell culture of a Chinese hamster was irradiated on a Serpuchov proton synchrotron at a dose of 0.5-4 Gy and a dose rate of 1 Gy/min and by gamma-irradiation at dose 1-5 Gy and dose rate 1.2-1.4 Gy/min. The effect of radiation on the cell culture was judged from chromosomal aberrations in G2-stage of cell cycle and micronuclear test. The relative biological efficience of the secondary radiation was approximately 3. Modifying effect of caffeine on the cells irradiated by secondary radiation of synchrotron was not observed. In the presence of caffeine the effect of gamma-irradiation practically is increased up to the level observed upon secondary irradiation. This suggests that secondary radiation inhibits the repair of the cytogenetic damage.     

Dosimetric investigations on Mars-96 mission.

The dosimetric experiments Dose-M and Liulin as part of the more complex French-German-Bulgarian-Russian experiments for the investigation of the radiation environment for Mars-96 mission are described. The experiments will be realized with dosemeter-radiometer instruments, measuring absorbed dose in semiconductor detectors and the particle flux. Two detectors will be mounted on board the Mars-96 orbiter. Another detector will be on the guiderope of the Mars-96 Aerostate station. The scientific aims of Dose-M and Liulin experiments are: Analysis of the absorbed dose and the flux on the path and around Mars behind different shielding. Study of the shielding characteristics of the Martian atmosphere from galactic and solar cosmic rays including solar proton events. Together with the French gamma-spectrometer and the German neutron detectors the investigation of the radiation environment on the surface of Mars and in the atmosphere up to 4000 m altitude will be conducted.     

Relative biological effectiveness and microdosimetry of a mixed energy field of protons up to 200 MeV.

We have studied radiation effects utilizing the new 250 MeV Synchrotron at Loma Linda University Medical Center. In this paper we present the data collected for the survival of Chinese hamster lung (V79) cells, that were irradiated with a beam of mixed energy protons up to 200 MeV. The RBE for protons, when compared to 60Co gamma rays, ranged from a low of 1.2 at the high energy portion of the field to 1.3+ at the low energy portion of the field. These results are consistent with the measured lineal energy (microdosimetric) spectra.