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Tomilovskaya E.S.,Institute for Biomedical Problems | Berger M.,Innsbruck Institute of Space Neurology | Gerstenbrand F.,Innsbruck Institute of Space Neurology | Kozlovskaya I.B.,Innsbruck Institute of Space Neurology
Journal of Vestibular Research: Equilibrium and Orientation | Year: 2013

The aim of the study was to examine effects of long-duration exposure to weightlessness on characteristics of the vertical gaze fixation reaction (GFR). The subjects were to perform the target acquisition task on visual stimuli that appeared at a distance of 16 deg. up- and down from the primary position in a random order. Experiments were performed before launch, during flight and after landing. Before flight time of gaze fixation reaction did not exceed 650 ms. During space flight (SF) it extended up to 900-1000 ms and more. The velocities of head movement in space decreased, but the velocities of eye counterrotation decreased to a lesser degree. This difference resulted in sharp increase of vertical vestibular ocular reflex (VOR) gain (up to 4.3 values in one of the cosmonauts) during the 1st month of flight; further it decreased reaching the values of 0.5-0.7 on the 5th month of SF. After landing vertical VOR gain increased greatly again. These results in the vertical axis are in agreement with the data of Kozlovskaya et al., which showed in experiments with monkeys that horizontal VOR gain increased together with redundant inadequate responses of vestibular nucleus on vestibular stimulation and that in the course of adaptation to these conditions central nervous system inhibited vestibular input from the motor control system. © 2013 - IOS Press and the authors. All rights reserved. Source


Johnsona P.J.,University of British Columbia | Asmarob D.,Simon Fraser University | Suedfeldc P.,University of British Columbia | Gushind V.,Institute for Biomedical Problems
Acta Astronautica | Year: 2012

Anecdotal evidence and qualitative research attest to the importance of work-family interactions pre-, during and post-missions. This study uses thematic content analysis to quantify characteristics of work-family interactions and how these changed by stage of cosmonauts' career, identifying the effect of space career variables (e.g., time in space and station) on such interactions during and post-career. Using a thematic scoring scheme developed for this study, we coded work-family interactions identified from interviews with 20 retired male cosmonauts. The majority of work-family interactions were ones in which work overlapped into family life and work hindered or interfered with the family situation. The most common resolution was that family adjusted to work, and the mood or tone about this outcome was almost equally divided among negative, positive and neutral. Changes in work-family interactions and their resolution over the cosmonaut's life showed that the significant interactions were most evident during the cosmonaut career. Although the cosmonaut career has high work demands, it did adjust for family when the need arose. The Russian Space Agency (RKS) eased the impact of the periodic absences, especially through regular communication sessions. Positive work-family interactions, i.e., work or family helping the opposite role, were more likely for those who had been on ISS, not Mir, and for those whose last flight was after 2000. Our data reflect retired cosmonauts' recollections of work-family interactions during their career. Examples of work overlapping into family life and work viewed as interfering with family life were possibly more salient or better remembered than work or family helping the other role. © 2012 Elsevier Ltd. All rights reserved. Source


Khristenko N.A.,Luxembourg Institute of Health | Khristenko N.A.,University of Luxembourg | Larina I.M.,Institute for Biomedical Problems | Domon B.,Luxembourg Institute of Health | Domon B.,University of Luxembourg
Journal of Proteome Research | Year: 2016

Urine is a valuable material for the diagnosis of renal pathologies and to investigate the effects of their treatment. However, the variability in protein abundance in the context of normal homeostasis remains a major challenge in urinary proteomics. In this study, the analysis of urine samples collected from healthy individuals, rigorously selected to take part in the MARS-500 spaceflight simulation program, provided a unique opportunity to estimate normal concentration ranges for an extended set of urinary proteins. In order to systematically identify and reliably quantify peptides/proteins across a large sample cohort, a targeted mass spectrometry method was developed. The performance of parallel reaction monitoring (PRM) analyses was improved by implementing tight control of the monitoring windows during LC-MS/MS runs, using an on-the-fly correction routine. Matching the experimentally obtained MS/MS spectra with reference fragmentation patterns allowed dependable peptide identifications to be made. Following optimization and evaluation, the targeted method was applied to investigate protein abundance variability in 56 urine samples, collected from six volunteers participating in the MARS-500 program. The intrapersonal protein concentration ranges were determined for each individual and showed unexpectedly high abundance variation, with an average difference of 1 order of magnitude. © 2015 American Chemical Society. Source


Basner M.,University of Pennsylvania | Dinges D.F.,University of Pennsylvania | Mollicone D.J.,Pulsar Informatics, Inc. | Savelev I.,Wyle | And 9 more authors.
PLoS ONE | Year: 2014

Behavioral health risks are among the most serious and difficult to mitigate risks of confinement in space craft during longduration space exploration missions. We report on behavioral and psychological reactions of a multinational crew of 6 healthy males confined in a 550 m3 chamber for 520 days during the first Earth-based, high-fidelity simulated mission to Mars. Rest-activity of crewmembers was objectively measured throughout the mission with wrist-worn actigraphs. Once weekly throughout the mission crewmembers completed the Beck Depression Inventory-II (BDI-II), Profile of Moods State short form (POMS), conflict questionnaire, the Psychomotor Vigilance Test (PVT-B), and series of visual analogue scales on stress and fatigue. We observed substantial inter-individual differences in the behavioral responses of crewmembers to the prolonged mission confinement and isolation. The crewmember with the highest average POMS total mood disturbance score throughout the mission also reported symptoms of depression in 93% of mission weeks, which reached mild-tomoderate levels in >10% of mission weeks. Conflicts with mission control were reported five times more often than conflicts among crewmembers. Two crewmembers who had the highest ratings of stress and physical exhaustion accounted for 85% of the perceived conflicts. One of them developed a persistent sleep onset insomnia with ratings of poor sleep quality, which resulted in chronic partial sleep deprivation, elevated ratings of daytime tiredness, and frequent deficits in behavioral alertness. Sleep-wake timing was altered in two other crewmembers, beginning in the first few months of the mission and persisting throughout. Two crewmembers showed neither behavioral disturbances nor reports of psychological distress during the 17-month period of mission confinement. These results highlight the importance of identifying behavioral, psychological, and biological markers of characteristics that predispose prospective crewmembers to both effective and ineffective behavioral reactions during the confinement of prolonged spaceflight, to inform crew selection, training, and individualized countermeasures. © 2014 Basner et al. Source


Heinse R.,University of Idaho | Jones S.B.,Utah State University | Or D.,ETH Zurich | Podolskiy I.,Institute for Biomedical Problems | And 3 more authors.
Vadose Zone Journal | Year: 2015

Water distribution patterns in pore spaces of particulate porous media directly control the resulting diffusion pathway for air required for biological activity (e.g., plant root respiration). Motivated by the potential of using plants for future life-support systems in space, the question arises whether fluid behavior in porous media is significantly altered under microgravity (»10−6gearth) conditions. Altered fluid phase distribution has been suspected in the onset of hypoxia in plant root modules under microgravity, yet the exact mechanisms remain uncertain. The Optimization of Root Zone Substrates (ORZS) experiment was the first to directly measure porous-media water retention and oxygen diffusion parameters under prolonged microgravity conditions (sufficient for equilibration of the fluid phases). Porous-ceramic aggregates tested included 1-to 2-mm Turface, 0.25-to 1-mm Profile, and a 50:50 mixture of both. Each porous medium had three replicates in a nine-cell array. The experiment used sealed dual-chamber diffusion cells controlled by an automated measurement system with water-content adjustment. Sensors measured matric potentials and water input or withdrawal in the media, along with oxygen concentrations dynamics in the gas-filled chambers confining the medium. The effective oxygen-diffusion coefficients were determined from temporal variations in measured oxygen-concentrations fitted to a Fickian-type relationship for the dual-chamber geometry. Ground-based determinations of matric potential and diffusion coefficients as a function of air-filled porosity were compared to microgravity data. Results pointed to enhanced hysteresis in the oxygen-diffusion dependency on bulk air-filled porosity in microgravity indicative of altered water-distribution patterns relative to Earth-based measurements. During drying we observed fundamentally different diffusivities in Profile and Mix attributed to nonuniform water distributions forming under drying conditions dominated by capillary and viscous forces in the absence of a hydrostatic force not observed on Earth. Water-retention parameters were not significantly different from Earth-based parameters, although gas diffusion parameters were significantly different for finer particle-sized media. The apparent reduction in the volume-averaged diffusive transport in microgravity may require adjustment in plant-growth system management protocols and model development for reliable response prediction of microgravity porous-medium systems. © Soil Science Society of America. Source

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