Danguolė Švegždienė, Danguolė Raklevičienė and Dalia Koryznienė
Švegždienė D., Raklevičienė D., Koryzienė D., 2013: Space botany in Lithuania. I. Root gravisensing system formation during satellite “Bion-10” flight [Kosminė botanika Lietuvoje. I. Gravitaciją juntančių šaknų ląstelių formavimasis palydovo „Bion-10“ skrydžio metu]. - Bot. Lith., 19(2): 129-138. The paper deals with the results of space experiment, which was carried out on an original automatically operating centrifuge „Neris-5“ on board of the satellite „Bion-10“ in 1993. The peculiarities of gravisensing system formation in roots of garden cress (Lepidium sativum L.) seedlings grown in microgravity under simulated and natural gravity of 1g in space and on the ground, respectively, are presented. Quantitative study on the growth of root columella cells (statocytes), the state of their intracellular components, and the location of amyloplasts was performed by light and electron microscopy. The growth of statocytes in microgravity and under 1g in space did not differ significantly though the location of amyloplasts experienced significant changes: it depended on the gravity and cell position in columella. Instead of the concentration of amyloplasts at the distal cell region of roots grown under 1g, most plastids in microgravity-grown roots were accumulated at the centre of statocytes. The obtained data on the formation and state of intercellular plastids confirm the supposition that the environment of microgravity alters the metabolism of plant cells; however, its alterations are not fateful for the formation of gravisensing cells and for the growth of the whole root.
Salivary and Serum 8-Hydroxydeoxyguanosine Level in Simulated Microgravity
Background. Microgravity is associated with an increased of peroxidative. The effect is more pronounced after long duration space flight and can even last for several weeks after landing.
Aim. To determine the influence of a simulated microgravity on antioxidant status of the human body.
Material and Methods. 10 healthy volunteers were studied in condition before, during, and just after the simulated microgravity of -6 head -down -tilt (HDT) bed rest for 10 days. We measured the salivary and serum 8-hydroxydeoxyguanosine before, during and recovery of HDT.
Results. The 8-hydroxydeoxyguanosine showed significant increase in simulating microgravity.
Conclusion. The data provides evidence that oxidative stress is among critical nutritional concerns for long duration space travellers.
Vladimír Pohánka, Peter Vajda and Jaroslava Pánisová
Here we investigate the applicability of the harmonic inversion method to time-lapse gravity changes observed in volcanic areas. We carry out our study on gravity changes occured over the period of 2004–2005 during the unrest of the Central Volcanic Complex on Tenerife, Canary Islands. The harmonic inversion method is unique in that it calculates the solution of the form of compact homogeneous source bodies via the mediating 3-harmonic function called quasigravitation. The latter is defined in the whole subsurface domain and it is a linear integral transformation of the surface gravity field. At the beginning the seeds of the future source bodies are introduced: these are quasi-spherical bodies located at the extrema of the quasigravitation (calculated from the input gravity data) and their differential densities are free parameters preselected by the interpreter. In the following automatic iterative process the source bodies change their size and shape according to the local values of quasigravitation (calculated in each iterative step from the residual surface gravity field); the process stops when the residual surface gravity field is sufficiently small. In the case of inverting temporal gravity changes, the source bodies represent the volumetric domains of temporal mass-density changes. The focus of the presented work is to investigate the dependence of the size and shape of the found source bodies on their differential densities. We do not aim here (yet) at interpreting the found solutions in terms of volcanic processes associated with intruding or rejuvenating magma and/or migrating volatiles.
Jakub Chromčák, Michal Grinč, Jaroslava Pánisová, Peter Vajda and Anna Kubová
We test here the feasibility of ground-penetrating radar (GPR) and microgravity methods in identifying underground voids, such as cellars, tunnels, abandoned mine-workings, etc., in complex urban conditions. For this purpose, we selected a cellar located under a private lot in a residential quarter of the town of Senec in Western Slovakia, which was discovered by chance when a small sinkhole developed on the yard just two meters away from the house. The size of our survey area was limited 1) by the presence of a technical room built at the back of the yard with a staircase leading to the garden, and 2) by the small width of the lot. Therefore the geophysical survey was carried out only in the backyard of the lot as we were not permitted to measure on neighbouring estates. The results from the GPR measurements obtained by the GSSI SIR-3000 system with 400 MHz antenna were visualized in the form of 2D radargrams with the corresponding transformed velocity model of studied cross-sections. Only the profiles running over the pavement next to the house yielded interpretable data because the local geological situation and the regular watering of the lawn covering prevailingly the backyard caused significant attenuation of the emitted GPR signal. The Bouguer gravity map is dominated by a distinctive negative anomaly indicating the presence of a shallow underground void. The quantitative interpretation by means of Euler deconvolution was utilized to validate the depth of the center and location of the cellar. Comparison with the gravitational effect of the cellar model calculated in the in-house program Polygrav shows a quite good correlation between the modelled and observed fields. Only a part of the aerial extent of the anomaly could be traced by the used geophysical methods due to accessibility issues. Nevertheless, the test cellar was successfully detected and interpreted by both methods, thus confirming their applicability in similar environmental and geotechnical applications, even in complex urban conditions.
This paper addresses the space experiments performed on board of the unmanned satellite “Bion-11” in 1997. To detail root gravity sensing in stimulus-free microgravity environment, researchers from the Institute of Botany developed an automatically operating centrifuge “Neris-8” to grow garden cress seedlings and to chemically fix them at the end of the experiments. There was examined behaviour of gravity sensors - amyloplasts within cap cells of roots responding to stimulation by artificial fractional gravity. The static of amyloplasts was determined in roots after continuous growth for 25 h in microgravity, 0.005, 0.02, 0.1 and 1-g environment. The movement kinetics of amyloplasts was studied in roots during the exposition to microgravity after 24-h growth in 1-g environment or conversely. Quantitative study on the patterns of positioning and movement of plastids was performed by light microscopy. The results obtained led us to detail a mode of gravity sensing by roots in which the interactions between moving amyloplasts, cytoplasm and cytoskeleton were discussed.
Pedro J. Llanos, Kristina Andrijauskaite, Vijay V. Duraisamy, Francisco Pastrana, Erik L. Seedhouse, Sathya Gangadharan, Leonid Bunegin and Mariel Rico
Cell Research Experiment In Microgravity (CRExIM) was launched aboard Blue Origin’s New Shepard suborbital vehicle on Tuesday, December 12, 2017, from the West Texas Launch Site in Van Horn, Texas. One of the aims of this science experiment was to assess the effects of microgravity on murine T-cells during suborbital flight. These cells were placed in a NanoLab with a data logger that sensed the acceleration, temperature, and relative humidity during preflight, flight, and postflight operations. Some discrepancies in sensor measurement were noticed, and these errors were attributed partly to the difference in sampling rates and partly to the different locations of the sensors, which made it difficult to obtain highly accurate measurements of the accelerations and to correlate both sets of data. This paper discusses the setbacks and lessons learned, which made our team find new alternatives while meeting all milestones as mandated by NanoRacks and Blue Origin. This manuscript highlights these alternatives that led to the success of the mission and gives recommendations that will enable customers to alleviate some of these challenges in future flights.
The use of microgravity technique in archaeology: A case study from the St. Nicolas Church in Pukanec, Slovakia
The detection of subsurface cavities, such as crypts, cellars and tunnels, in churches and castles belongs to successful applications of the employment of surface gravity measurement techniques in archaeo-prospecting. The old historic building exploration requires using of non-invasive methods, and hence the microgravity technique is a proper candidate for this task. On a case study from the Roman-Catholic Church of St. Nicolas in the town Pukanec the results of using microgravity for detection and delineation of local density variations caused by a near-surface void are shown. The acquired negative anomaly in the residual Bouguer anomalies field suggested the presence of a possible void feature. Euler deconvolution and 3D modelling were used to estimate the depth and shape of the anomalous source. Additionally, measurements of the vertical gravity gradient on several stations were performed. We tested how the use of a downward continuation of gravity, utilizing the real vertical gravity gradient, influences the shape and amplitude of the final Bouguer anomaly map.
Arayik Martirosyan, Lawrence J. DeLucas, Christina Schmidt, Markus Perbandt, Deborah McCombs, Martin Cox, Christopher Radka and Christian Betzel
To investigate the effect of macromolecular transport and the incorporation of protein aggregate impurities in growing crystals, experiments were performed on the International Space Station (ISS) and compared with control experiments performed in a 1G laboratory environment. Crystal growth experiments for hen egg-white lysozyme (HEWL) and Plasmodium falciparum glutathione S-transferase (PfGST) were monitored using the ISS Light Microscopy Module (LMM). Experiments were performed applying the liquid–liquid counter diffusion crystallization method using rectangular, optically transparent capillaries. To analyze the quantity of impurity incorporated into growing crystals, stable fluorescently labeled protein aggregates were prepared and subsequently added at different percent concentrations to nonlabeled monomeric protein suspensions. For HEWL, a covalent cross-linked HEWL dimer was fluorescently labeled, and for PfGST, a stable tetramer was prepared. Crystallization solutions containing different protein aggregate ratios were prepared. The frozen samples were launched on 19.02.2017 via SpaceX-10 mission and immediately transferred to a -80°C freezer on the ISS. Two series of crystallization experiments were performed on ISS, one during 26.02.2017 to 10.03.2017 and a second during 16.06.2017 to 23.06.2017. A comparison of crystal growth rate and size showed different calculated average growth rates as well as different dimensions for crystals growing in different positions along the capillary. The effect of macromolecular mass transport on crystal growth in microgravity was experimentally calculated. In parallel, the percentage of incorporated fluorescent aggregate into the crystals was monitored utilizing the fluorescent LMM and ground-based fluorescent microscopes.
Research indicates that exposure to microgravity leads to immune system dysregulation. However, there is a lack of clear evidence on the specific reasons and precise mechanisms accounting for these immune system changes. Past studies investigating space travel-induced alterations in immunological parameters report many conflicting results, explained by the role of certain confounders, such as cosmic radiation, individual body environment, or differences in experimental design. To minimize the variability in results and to eliminate some technical challenges, we advocate conducting thorough feasibility studies prior to actual suborbital or orbital space experiments. We show how exposure to suborbital flight stressors and the use of a two-dimensional slow rotating device affect T-cells and cancer cells survivability. To enhance T-cell activation and viability, we primed them alone or in combination with IL-2 and IL-12 cytokines. Viability of T-cells was assessed before, during the experiment, and at the end of the experiment for which T-cells were counted every day for the last 4 days to allow the cells to form clear structures and do not disturb their evolution into various geometries. The slow rotating device could be considered a good system to perform T-cell activation studies and develop cell aggregates for various types of cells that react differently to thermal stressors.
Peculiarity of Ultrastructure and 45Ca Methabolism of Osteoclasts in Conditions of Hind Limb Unloading and Microgravity
Using methods of electron microscopy, morphometry and cytochemistry the peculiarities of ultrastructure of osteoclasts and resorptive processes of the mineralized matrix in spongy bone of the rat femoral bone metaphyses following the experimental hind limb unloading model (28 days), as well as in rats exposed on American Space Station SLS—2 (2 weeks) were studied. The methods of light and electron microscopy radioautography 45Ca were used in the experiment of hind limbs unloading. The results of investigations demonstrated that in zones of adaptive remodeling the resorption and destruction processes in the bone tissue increase under the supportive unloading. It takes place by increasing of functional activity of osteoclasts (in microgravity conditions we registered the «giant» osteoclasts). The dynamics of 45Ca —incorporation into osteoclasts is an indicator of a direct involvement of cells in calcium transfer from the resorpting mineralized matrix to intercellular environment and intensification of this process at hind limb unloading model.