On-ground Control Research Articles

SCD \u2013 Stem Cell Differentiation Toward Osteoblast Onboard the International Space Station

Microgravity produces a variety of physical, chemical, and biological cues leading to an intricate and largely unresolved network of mechanosensitive molecules, transduction pathways, oxidative stress-related responses, and adaptations. The bone loss observed in astronauts and animal models after spaceflight is attributable to alterations in the bone tissue formation that depends on the continuous remodelling through the activities of bone-resorbing osteoclasts of hematopoietic lineage and bone-forming osteoblast of mesenchymal origin. Focusing on osteogenic differentiation, we present the results of the ”SCD - Stem Cells Differentiation” experiment, aiming to determine how human bone marrow stem cells (hBMSCs) react to a prolonged (approx. 2 weeks) exposure to microgravity in terms of growth, and differentiation when treated with a physiological osteo-inducer as 1,25-dihydroxy vitamin D (Vit D3). The experiment was selected by the European Space Agency and transferred to ISS with the Soyuz-TMA- 16M (ISS 42S). It was carefully prepared because experiments performed on ISS remain a uniquely exceptional means of clarifying the microgravitational effects on osteogenesis, often only partially activated and detectable under simulated conditions. Because of the substantial reduction in calcification observed (about 50% inflight vs. on-ground control), we looked at significantly affected pathways in hBMSCs grown in microgravity vs. on-ground controls. Genome-wide expression changes were assessed via microarray and next generation sequencing (NGS) and integrated with exosomal mi-RNA measurements. Multi-scale pathway analysis of the omics datasets revealed evidence of cell cycle arrest, occurring with a number of osteogenic gene markers, but without indications of adipogenesis, senescence and/or apoptosis.

On-ground aircraft control design using a parameter-varying anti-windup approach

As an original alternative to dynamic inversion techniques, a non-standard anti-windup control strategy is developed in this paper in order to improve the on-ground control system of a civilian aircraft. Using a linear fractional representation (LFR) of the aircraft in combination with an original approximation of the nonlinear ground forces by saturation-type nonlinearities, the proposed design method delivers low-order and robust controllers, which are automatically adapted to the runway state and to the aircraft longitudinal velocity. The efficiency of the design scheme is assessed by several nonlinear simulations.

Transcriptomic analyses of space-induced rice mutants with enhanced susceptibility to rice blast

Mutagenic factors of the space environment influence organisms in different aspects. To elucidate the transcriptomic effects of space flight, a space flight-induced rice mutant, 972-4, and its on-ground control, 972ck, were inoculated with rice blast pathogens. Compared to the control, the mutant exhibited reduced resistance to the rice blast pathogen CH45. Microarray technique was employed to analyze affected genes and revealed that 481 genes were expressed at higher levels in the mutant strain and 188 genes were expressed at higher levels in the control strain under normal growth conditions, indicating that transcriptomic changes of rice seeds are induced by the space environment. After inoculation with the rice blast pathogen CH45, however, 2680 genes were differentially expressed in 972ck and 1863 genes were differentially expressed in 972-4. In addition, disease evaluation indicated that the control strain 972ck is more resistant to the rice blast pathogen CH45 than mutant strain 972-4. In addition, genes in both strains that were co-regulated after blast inoculation account for only 36.8% and 53.3% of the genes expressed in 972ck and 972-4, respectively. A large percentage of blast-regulated genes were not consistently expressed in 972-4 and 972ck, and the mutant and control strains exhibit different gene expression patterns after blast inoculation. Interestingly, 84 genes constitutively expressed higher in 972ck were up-regulated by blast inoculation, and 105 genes that were expressed at constitutively higher levels in 972-4 were down-regulated by blast inoculation. Of the differentially expressed, 7 encoded genes associated with pathogen resistance. Taken together, our results suggest that gene expression patterns are different between a space flight-induced rice mutant and its on-ground control, and the differential expression of resistance genes may be a potential mechanism that modulates the resistance of 972-4 to rice blast. Our results also suggest that the rice plants are suitable plant models for further research of the effects of the space environment on gene expression and function.

Real and simulated microgravity can activate signals stimulating cells to enter the S phase during lens regeneration in urodelean amphibians

The model of Wolffian lens regeneration was used to study the effect of microgravity on the proliferative activity of cell giving rise to the regenerating lens. In vivo experiments were performed aboard Russian biosatellites and under laboratory conditions, using clinorotation to simulate microgravity. The data of autoradiographic analysis and BrdU assay showed that exposure to micro- g resulted in a 1.2- to 2-fold increase in the number of cells entering the S phase, compared to that in the on-ground control (1 g). This increase was observed both in the zone of regeneration (the dorsal iris) and in the eye growth zone (the pars ciliaris–ora serrata complex). In the regenerating lens proper, the number of cells entering the S phase was also greater under experimental conditions. This often resulted in an increased size of the lens (compared to the control) and disturbances in its morphogenesis. Along with in vivo experiments, we developed a quasi-in vivo system of iris/lens culturing in vitro in a high-speed miniroller, which allows us now to compare the direct effects of low g and the effects mediated by various body systems on proliferation in the same eye tissues. Probable mechanisms of the influence of newt body systems on lens regeneration upon exposure to microgravity are discussed. A hypothesis is proposed that the key role in this influence may belong to early events in the responses of blood circulatory and immune systems to microgravity.

Real and simulated microgravity can activate signals stimulating cells to enter the S phase during lens regeneration in urodelean amphibians

The model of Wolffian lens regeneration was used to study the effect of microgravity on the proliferative activity of cell giving rise to the regenerating lens. In vivo experiments were performed aboard Russian biosatellites and under laboratory conditions, using clinorotation to simulate microgravity. The data of autoradiographic analysis and BrdU assay showed that exposure to micro-g resulted in a 1.2- to 2-fold increase in the number of cells entering the S phase, compared to that in the on-ground control (1g). This increase was observed both in the zone of regeneration (the dorsal iris) and in the eye growth zone (the pars ciliaris–ora serrata complex). In the regenerating lens proper, the number of cells entering the S phase was also greater under experimental conditions. This often resulted in an increased size of the lens (compared to the control) and disturbances in its morphogenesis. Along with in vivo experiments, we developed a quasi-in vivo system of iris/lens culturing in vitro in a high-speed miniroller, which allows us now to compare the direct effects of low g and the effects mediated by various body systems on proliferation in the same eye tissues. Probable mechanisms of the influence of newt body systems on lens regeneration upon exposure to microgravity are discussed. A hypothesis is proposed that the key role in this influence may belong to early events in the responses of blood circulatory and immune systems to microgravity.

On the Role of Star Catalogues for Autonomous Space Navigation

The questions connected with constructing modern systems of autonomous navigation for spacecraft are considered. Increasing importance of these systems is shown, which is due to: a sharp increase in a number of spacecraft launches and congestion of on-ground control centers; and a necessity to provide more accurate and timely determination of motion parameters and motion control of spacecraft during their flights to the Solar System's celestial bodies. Importance of the star sighting and angular measurements connected with stars for adequate solution of space navigation problems is shown. Thus the star catalogues play a significant role for constructing navigational algorithms.