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701.
Ultrastructural and growth indices of Chlorella culture in multicomponent aquatic systems under space flight conditions. 总被引:2,自引:0,他引:2
A F Popova K M Sytnik E L Kordyum G I Meleshko V N Sychev M A Levinskykh 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》1989,9(11):79-82
Submicroscopic organization of Chlorella cells cultivated under space flight conditions in three-component aquatic system has been studied. Comparison of the experimental cells with that of the controls revealed certain rearrangements of cell organelles particularly, a reduction in the amount of reserve polysaccharides in chloroplasts, increase of cell vacuolization and mitochondrion volume, complication configuration of plasmalemma evaginations and invaginations, and also disturbances in the process of cytokinesis. More over an increase in the number of Chlorella cells infected by bacteria was shown in the experimental variant. No considerable differences were established in the growth characteristics of the experimental and control populations. A comparative cytological analysis revealed general regularities of organelles in Chlorella cells cultivated under space flight condition in the uni- and multicomponent systems. 相似文献
702.
Cork L. Clothier R. Gonzalez L.F. Walker R. 《Aerospace and Electronic Systems Magazine, IEEE》2007,22(11):29-44
The outcomes of "the future of UAS: standards, regulations and operational experiences" workshop, held on the 7 -8 December 2006, in Brisbane, Queensland, Australia. The goal of the workshop was to identify recent international activities in the unmanned airborne systems (UAS) airspace integration problem. The workshop attracted a broad cross-section of the UAS community, including: airspace and safety regulators, developers, operators, and researchers. The three themes of discussion were: progress in the development of standards and regulations; lessons learnt from recent operations; and advances in new technologies. This summarises the activities of the workshop and explores the important outcomes and trends as perceived by these authors. 相似文献
703.
N Desai M Durante Z W Lin F Cucinotta H Wu 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2005,35(2):236-242
We investigated the spatial distribution of the induction of the phosphorylated form of the histone protein H2AX (gamma-H2AX), known to be activated by DSBs. Following irradiation of human fibroblast cells with 600 MeV/nucleon silicon and 600 MeV/nucleon iron ions we observed the formation of gamma-H2AX aggregates in the shape of streaks stretching over several micrometers in an x/y plane. Polyethylene shielding was used to achieve a Bragg curve distribution with beam geometry parallel to the monolayer of cells. We present data that highlights the formation of immunofluorescent gamma-H2AX tracks showing the ion trajectories across the Bragg peak of irradiated human fibroblast cells. Qualitative analyses of these distributions indicated potentially increased clustering of DNA damage before the Bragg peak, enhanced gamma-H2AX distribution at the peak, and provided visual evidence of high-linear energy transfer particle traversal of cells beyond the Bragg peak in agreement with one-dimensional transport approximations. Spatial assessment of gamma-H2AX fluorescence may provide direct insights into DNA damage across the Bragg curve for high charge and energy ions including the biological consequences of shielding and possible contributors to bystander effects. 相似文献
704.
J. G. Trotignon J. L. Michau D. Lagoutte M. Chabassière G. Chalumeau F. Colin P. M. E. Décréau J. Geiswiller P. Gille R. Grard T. Hachemi M. Hamelin A. Eriksson H. Laakso J. P. Lebreton C. Mazelle O. Randriamboarison W. Schmidt A. Smit U. Telljohann P. Zamora 《Space Science Reviews》2007,128(1-4):713-728
The main objective of the Mutual Impedance Probe (MIP), part of the Rosetta Plasma Consortium (RPC), is to measure the electron
density and temperature of Comet 67P/Churyumov-Gerasimenko’s coma, in particular inside the contact surface. Furthermore,
MIP will determine the bulk velocity of the ionised outflowing atmosphere, define the spectral distribution of natural plasma
waves, and monitor dust and gas activities around the nucleus. The MIP instrumentation consists of an electronics board for
signal processing in the 7 kHz to 3.5 MHz range and a sensor unit of two receiving and two transmitting electrodes mounted
on a 1-m long bar. In addition, the Langmuir probe of the RPC/LAP instrument that is at about 4 m from the MIP sensor can
be used as a transmitter (in place of the MIP ones) and MIP as a receiver in order to have access to the density and temperature
of plasmas at higher Debye lengths than those for which the MIP is originally designed. 相似文献
705.
D F Smart M A Shea 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2002,30(4):1033-1044
Solar cycle 22 had significant, large fluence, energetic particle events on a scale reminiscent of the 19th solar cycle. Examination of the characteristics of these large events suggests that some of the old concepts of spectral form, intensity-time envelope and energy extrapolations, used to estimate the dose from large events that occurred during previous solar cycles should be re-evaluated. There has also been a dramatic change in perspective regarding the source of solar protons observed in interplanetary space. Very large fluence events are associated with powerful fast interplanetary shocks. The elemental composition and charge state of these events is suggestive of a dominate source in the solar corona and not from a very hot plasma. Furthermore, there is a strong suggestion that the intensity-time profile observed in space is dominated by the connection of the observer to an interplanetary shock source rather than to a unique location near the surface of the sun. These concepts will be examined from the perspective of energetic particles contributing to the dose experienced by an astronaut on an interplanetary space mission. 相似文献
706.
707.
N F Mikhaylenko S K Sytnik E K Zolotareva 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,27(5):1007-1010
Photochemical characteristics and lipid composition of thylakoid membranes from 12 day-old pea leaves that were exposed to slow clino-rotation were examined and compared with a vertical control. Proton permeability of thylakoid membranes was estimated from light-induced proton uptake (delta H+) and post-illumination proton efflux in chloroplast suspensions. The delta pH magnitude was calculated from the level of light-induced quenching of 9-aminoacridine fluorescence. Proton permeability of thylakoid membranes increased during exposure to clino-rotation. When subsequently transferred to darkness, proton efflux increased almost 2-fold in clinorotated leaves. The results were compared with data on pigment and polar lipid composition of photosynthetic membranes in clino-rotated and control plants. It was concluded that both the increase of proton permeability and the decrease of polar lipid content in chloroplasts were induced by clino-rotation. 相似文献
708.
F Raulin K Kobayashi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,27(2):185-187
During COSPAR'00 in Warsaw, Poland, in the frame of Sub-Commission F.3 events (Planetary Biology and Origins of Life), part of COSPAR Commission F (Life Sciences as Related to Space), and Commission B events (Space Studies of the Earth-Moon System, Planets, and Small Bodies of the Solar System) a large joint symposium (F.3.4/B0.8) was held on extraterrestrial organic chemistry. Part 2 of this symposium was devoted to complex organic chemistry in the environment of planets and satellites. The aim of this event was to cover and review new data which have been recently obtained and to give new insights on data which are expected in the near future to increase our knowledge of the complex organic chemistry occurring in several planets and satellites of the Solar System, outside the earth, and their implications for exobiology and life in the universe. The event was composed of two main parts. The first part was mainly devoted to the inner planets and Europa and the search for signatures of life or organics in those environments. The second part was related to the study of the outer solar system. 相似文献
709.
The equations of motion for the stable member of a threegimbal platform are presented [3]. These equations are combined with models of the three platform control loops to formulate a model for the system. The system model is simplified and a digital simulation is developed for studying the motion of the stable member under conditions of dynamic vehicle angular environment. 相似文献
710.
A problem f requently encountered by radar systems analysts is the evaluation of the "double-threshold" or M out of N detection process. Detection probabilities of this process are binomially distributed, making it difficult to obtain exact results for large values of the number of samples and for low probabilities of false alarm. In this paper, the M out of N detection algorithm is defined and detection performance is calculated for the special cases of the nonfluctuating target and Swerling cases I and 11 for false alarm probabilities of 106, 10-8 and 10-10. 相似文献