Life-span of irradiated mammals. Mathematical modelling

A mathematical model of the mortality dynamics of irradiated mammals is developed. It relates the statistical biometrical functions with the statistical and kinetical characteristics of the critical systems in the organism. This model can be used for predicting the life shortening of irradiated mammals.     

The Swift Ultra-Violet/Optical Telescope

The Ultra-Violet/Optical Telescope (UVOT) is one of three instruments flying aboard the Swift Gamma-ray Observatory. It is designed to capture the early (∼1 min) UV and optical photons from the afterglow of gamma-ray bursts in the 170–600 nm band as well as long term observations of these afterglows. This is accomplished through the use of UV and optical broadband filters and grisms. The UVOT has a modified Ritchey–Chrétien design with micro-channel plate intensified charged-coupled device detectors that record the arrival time of individual photons and provide sub-arcsecond positioning of sources. We discuss some of the science to be pursued by the UVOT and the overall design of the instrument.     

Biomedical program of the ALTAIR french russian flight onboard the MIR station

One year after the achievemant of the 2 weeks ANTARES french-russian mission in the MIR station in July 1992, a 22 days ALTAÏR mission with a french cosmonaut has been performed in July 1993, making use of the scientific payload remaining on board. Taking benefit of the analysis of the previous mission, the experimental protocols were adapted to refine scientific objectives and gave to the scientists the opportunity to enhance quantitatively and qualitatively their results. The french biomedical program, conducted in close scientific cooperation with IMBP and associated laboratories, was composed of 8 experiments out of which 2 were new with regards to the ANTARES program. In the field of cardio-vascular physiology and fluid regulation, the experiments: ORTHOSTATISME, DIURESE have been renewed and complemented by the TISSU experiment (proposed by a german scientist) and a real-time tele-assistance program using US echography technic and ground support from the french CADMOS support control center located in Toulouse. With respect to neurosciences objectives, to the experiments VIMINAL (cognitive processes) and ILLUSIONS (study of proprioceptives cues), was added the SYNERGIES experiment to analyse the postural adjustements during movement. The IMMUNOLOGIE experiment carried on and the radiobiological experiment BIODOSE ended.

Adding the results of the 2 missions ANTARES and ALTAÏR, and the data obtained in between onboard with russian cosmonauts, the scientists have received a wealth of physiological data and gained reproducibility and confidence in their results.     

Summary of experiments onboard Soviet biosatellites.

Physiological, morphological and biochemical studies of mammals flown onboard biosatellites of the series Cosmos revealed changes in their cardiovascular, musculoskeletal, endocrine and vestibular systems. Space flight resulted in moderate stress reactions, intralabyrinthine conflict information during movements and changes in fluid-electrolyte metabolism. Exposure to artificial gravity (1 g) decreased the level of myocardial, musculoskeletal and excretory changes, but disturbed the function of equilibrium. Studies with combined weightlessness and ionizing radiation demonstrated that weightlessness did not produce a significant modifying effect on radiation damage and postradiation recovery. Consistent changes in certain systems of animals and humans in weightlessness confirm the practical importance of biosatellite studies, which also contribute to the solution of general biology, problems associated with gravity effects on life processes.     

Large and sharp changes of solar wind dynamic pressure and disturbances of the magnetospheric magnetic field at geosynchronous orbit caused by these variations

The large and sharp changes of solar wind dynamic pressure, found from the INTERBALL-1 satellite and WIND spacecraft data, are compared with simultaneous magnetic field disturbances in the magnetosphere measured by geosynchronous GOES-8, GOES-9, and GOES-10 satellites. For this purpose, about 200 events in the solar wind, associated with sharp changes of the dynamic pressure, were selected from the INTERBALL-1 satellite data obtained during 1996–1999. The large and sharp changes of the solar wind dynamic pressure were shown to result in rapid variations of the magnetic field strength in the outer magnetosphere, the increase (drop) of the solar wind dynamic pressure always lead to an increase (drop) of the geosynchronous magnetic field magnitude. The value of the geomagnetic field variation strongly depends on the local time of the observation point, reaching a maximum value near the noon meridian. It is shown that the direction of the B _z component of the interplanetary magnetic field has virtually no effect on the geomagnetic field variation because of a sharp jump of pressure. The time shift between an event in the solar wind and its response in the magnetosphere at a geosynchronous orbit essentially depends on the inclination of the front of a solar wind disturbance to the Sun-Earth line.     

Social and cultural issues during Shuttle/Mir space missions.

A number of interpersonal issues relevant to manned space missions have been identified from the literature. These include crew tension, cohesion, leadership, language and cultural factors, and displacement. Ground-based studies by others and us have clarified some of the parameters of these issues and have indicated ways in which they could be studied during actual space missions. In this paper, we summarize some of our findings related to social and cultural issues from a NASA-funded study conducted during several Shuttle/Mir space missions. We used standardized mood and group climate measures that were completed on a weekly basis by American and Russian crew and mission control subjects who participated in these missions. Our results indicated that American subjects reported more dissatisfaction with their interpersonal environment than their Russian counterparts, especially American astronauts. Mission control personnel were more dysphoric than crewmembers, but both groups were significantly less dysphoric than other work groups on Earth. Countermeasures based on our findings are discussed which can be applied to future multicultural space missions.     

European spaceflight at the crossroads

Plans for Europe's future participation in space development are still under active discussion. This article offers a contribution to the debate, considering how Europe can best fulfil its own objectives. Choice of launch vehicle and its payload, as well as of other tools such as space station, re-entry vehicle, and launch site equipment are analysed. The article also discusses the purposes of space research for Europe, and the costs of a useful programme. A far-reaching European space programme still needs to be drawn up if Europe is not to lose out.     

仿生物态模拟型硬件理论与关键技术研究

阐述了模拟型仿生硬件的概念、基本思想与技术瓶颈，分析了基于FPTA(Field programmable transistor array)的模拟型仿生硬件的结构与电子细胞电路工作原理。给出了模拟型仿生硬件的电路编码方案、个体电路测试评估方法和进化实现过程。提出了基于单染色体自适应变异进化机制的模拟型仿生硬件进化算法。以信号放大器、半波整流器、异或门数字电路作为典型应用实例，来验证模拟型仿生硬件的进化特性，并讨论了进化算法的参数选取、染色体适应度评估问题。仿真结果表明：所提出硬件进化算法的进化速度快、成功率高，所设计的FPTA细胞阵列可以实现模拟信号放大、信号处理和数字电路逻辑功能。     

Inconsistency of magnetic field and plasma velocity variations in the distant plasma sheet: Violation of the “frozen-in” criterion?

Measurements of the magnetic field and low energy plasma by the GEOTAIL spacecraft have been used to study the relationship between variations of the plasma velocity and of the magnetic field in the distant (100–200 R_E) and middle (40–80 R_E) tail. The analysis was carried out separately for the tail lobes and the plasma sheet. It is shown that the absolute values of the magnetic field and plasma velocity, as well as their corresponding components (V_X and B_X, V_Y and B_Y, V_Z and B_Z), are linearly connected in the tail lobes. In the plasma sheet, however, the plasma velocity and the magnetic field do not seem to be related to one another. The distant plasma sheet seems to be in a regime of turbulence. The diffusion coefficients estimated from our data set of the velocity parameters in the plasma sheet are in good agreement with the theoretical predictions of Antonova and Ovchinnikov (1996, 1999).