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1.
PLoS One ; 16(8): e0245642, 2021.
Article in English | MEDLINE | ID: mdl-34375334

ABSTRACT

The study aimed to model and quantify the health burden induced by four non-communicable diseases (NCDs) in Egypt, the first to be conducted in the context of a less developing county. The study used the State-Space model and adopted two Bayesian methods: Particle Filter and Particle Independent Metropolis-Hastings to model and estimate the NCDs' health burden trajectories. We drew on time-series data of the International Health Metric Evaluation, the Central Agency for Public Mobilization and Statistics (CAPMAS) Annual Bulletin of Health Services Statistics, the World Bank, and WHO data. Both Bayesian methods showed that the burden trajectories are on the rise. Most of the findings agreed with our assumptions and are in line with the literature. Previous year burden strongly predicts the burden of the current year. High prevalence of the risk factors, disease prevalence, and the disease's severity level all increase illness burden. Years of life lost due to death has high loadings in most of the diseases. Contrary to the study assumption, results found a negative relationship between disease burden and health services utilization which can be attributed to the lack of full health insurance coverage and the pattern of health care seeking behavior in Egypt. Our study highlights that Particle Independent Metropolis-Hastings is sufficient in estimating the parameters of the study model, in the case of time-constant parameters. The study recommends using state Space models with Bayesian estimation approaches with time-series data in public health and epidemiology research.


Subject(s)
Noncommunicable Diseases/epidemiology , Bayes Theorem , Cost of Illness , Egypt/epidemiology , Global Burden of Disease/methods , Global Health , Health Services , Humans , Patient Acceptance of Health Care , Risk Factors , Space Simulation/methods
3.
Astrobiology ; 20(9): 1029-1047, 2020 09.
Article in English | MEDLINE | ID: mdl-31916858

ABSTRACT

Sulfate and iron oxide deposits in Río Tinto (Southwestern Spain) are a terrestrial analog of early martian hematite-rich regions. Understanding the distribution and drivers of microbial life in iron-rich environments can give critical clues on how to search for biosignatures on Mars. We simulated a robotic drilling mission searching for signs of life in the martian subsurface, by using a 1m-class planetary prototype drill mounted on a full-scale mockup of NASA's Phoenix and InSight lander platforms. We demonstrated fully automated and aseptic drilling on iron and sulfur rich sediments at the Río Tinto riverbanks, and sample transfer and delivery to sterile containers and analytical instruments. As a ground-truth study, samples were analyzed in the field with the life detector chip immunoassay for searching microbial markers, and then in the laboratory with X-ray diffraction to determine mineralogy, gas chromatography/mass spectrometry for lipid composition, isotope-ratio mass spectrometry for isotopic ratios, and 16S/18S rRNA genes sequencing for biodiversity. A ubiquitous presence of microbial biomarkers distributed along the 1m-depth subsurface was influenced by the local mineralogy and geochemistry. The spatial heterogeneity of abiotic variables at local scale highlights the importance of considering drill replicates in future martian drilling missions. The multi-analytical approach provided proof of concept that molecular biomarkers varying in compositional nature, preservation potential, and taxonomic specificity can be recovered from shallow drilling on iron-rich Mars analogues by using an automated life-detection lander prototype, such as the one proposed for NASA's IceBreaker mission proposal.


Subject(s)
Exobiology/methods , Extraterrestrial Environment/chemistry , Geologic Sediments/analysis , Mars , Bacteria/chemistry , Bacteria/metabolism , Biomarkers/analysis , Biomarkers/chemistry , Biomarkers/metabolism , Ferric Compounds/analysis , Ferric Compounds/chemistry , Gas Chromatography-Mass Spectrometry , Geologic Sediments/chemistry , Geologic Sediments/microbiology , Iron Compounds/analysis , Iron Compounds/chemistry , Lipids/analysis , Lipids/chemistry , Minerals/analysis , Minerals/chemistry , Rivers/chemistry , Rivers/microbiology , Robotics , Space Simulation/methods , Spain , Sulfates/analysis , Sulfates/chemistry , X-Ray Diffraction
4.
EMBO Rep ; 20(7): e48541, 2019 07.
Article in English | MEDLINE | ID: mdl-31267713

ABSTRACT

Experiments in space and on free-fall platforms have yielded important insights into plant's reaction to low gravity with potential applications for space research and exploration.


Subject(s)
Plant Physiological Phenomena , Weightlessness , Crop Production/methods , Exobiology/methods , Space Simulation/methods
5.
Life Sci Space Res (Amst) ; 21: 65-72, 2019 May.
Article in English | MEDLINE | ID: mdl-31101156

ABSTRACT

Space radiation is one of the main concerns for human space flights. The prediction of the radiation dose for the actual spacecraft geometry is very important for the planning of long-duration missions. We present a numerical method for the fast calculation of the radiation dose rate during a space flight. We demonstrate its application for dose calculations during the first and the second sessions of the MATROSHKA-R space experiment with a spherical tissue-equivalent phantom. The main advantage of the method is the short simulation time, so it can be applied for urgent radiation dose calculations for low-Earth orbit space missions. The method uses depth-dose curve and shield-and-composition distribution functions to calculate a radiation dose at the point of interest. The spacecraft geometry is processed into a shield-and-composition distribution function using a ray-tracing method. Depth-dose curves are calculated using the GEANT4 Monte-Carlo code (version 10.00.P02) for a double-layer aluminum-water shielding. Aluminum-water shielding is a good approximation of the real geometry, as water is a good equivalent for biological tissues, and aluminum is the major material of spacecraft bodies. The method is applied to model the dose distribution on the surface of the spherical phantom in the MATROSHKA-R space experiment. The experiment has been carried out onboard the ISS from 2004 to the present. The absorbed dose was determined in 32 points on the phantom's surface. We find a good agreement between the data obtained in the experiment and our calculation results. The simulation method is thus applicable for future radiation dose predictions for low-Earth orbit missions and experiments.


Subject(s)
Cosmic Radiation , Phantoms, Imaging , Radiation Monitoring/instrumentation , Space Simulation/methods , Spacecraft/instrumentation , Humans , International Agencies , Monte Carlo Method , Radiation Dosage
6.
Astrobiology ; 19(3): 347-368, 2019 03.
Article in English | MEDLINE | ID: mdl-30840500

ABSTRACT

Short-term and long-term science plans were developed as part of the strategic planning process used by the Biologic Analog Science Associated with Lava Terrains (BASALT) science team to conduct two Mars-simulation missions investigating basalt habitability at terrestrial volcanic analog sites in 2016. A multidisciplinary team of scientists generated and codified a range of scientific hypotheses distilled into a Science Traceability Matrix (STM) that defined the set of objectives pursued in a series of extravehicular activity (EVA) campaigns performed across multiple field deployments. This STM was used to guide the pre-deployment selection of sampling stations within the selected Mars analog sites on the Earth based on precursor site information such as multispectral imagery. It also informed selection of hand-held instruments and observational data to collect during EVA to aid sample selection through latency-impacted interaction with an Earth-based Science Support Team. A significant portion of the pre-deployment strategic planning activities were devoted to station selection, ultimately the locations used for sample collection and EVA planning. During development of the EVAs, the BASALT science team identified lessons learned that could be used to inform future missions and analog activities, including the critical need for high-resolution precursor imagery that would enable the selection of stations that could meet the scientific objectives outlined in the STM.


Subject(s)
Exobiology/organization & administration , Extravehicular Activity , Mars , Space Simulation/methods , Strategic Planning , Exobiology/methods , Exobiology/trends , Forecasting
7.
Astrobiology ; 19(3): 478-496, 2019 03.
Article in English | MEDLINE | ID: mdl-30840502

ABSTRACT

There is a synergistic relationship between analog field testing and the deep space telecommunication capabilities necessary for future human exploration. The BASALT (Biologic Analog Science Associated with Lava Terrains) research project developed and implemented a telecommunications architecture that serves as a high-fidelity analog of future telecommunication capabilities for Mars. This paper presents the architecture and its constituent elements. The rationale for the various protocols and radio frequency (RF) link types required to enable an interdisciplinary field mission are discussed, and the performance results from the BASALT field tests are provided. Extravehicular Informatics Backpacks (EVIB) designed for BASALT and tested by human subjects are also discussed, and the proceeding sections show how these prototype extravehicular activity (EVA) information systems can augment future human exploration. The paper concludes with an aggregate analysis of the data product types and data volumes generated, transferred, and utilized by the ground team and explorers over the course of the field deployments.


Subject(s)
Exobiology/organization & administration , Extraterrestrial Environment , Mars , Space Flight/organization & administration , Telecommunications/organization & administration , Exobiology/trends , Forecasting , Humans , Information Systems/organization & administration , Information Systems/trends , Space Flight/trends , Space Simulation/methods , Telecommunications/trends , United States , United States National Aeronautics and Space Administration
8.
Astrobiology ; 19(3): 440-461, 2019 03.
Article in English | MEDLINE | ID: mdl-30840505

ABSTRACT

Future human missions to Mars are expected to emphasize scientific exploration. While recent Mars rover missions have addressed a wide range of science objectives, human extravehicular activities (EVAs), including the Apollo missions, have had limited experience with science operations. Current EVAs are carefully choreographed and guided continuously from Earth with negligible delay in communications between crew and flight controllers. Future crews on Mars will be expected to achieve their science objectives while operating and coordinating with a science team back on Earth under communication latency and bandwidth restrictions. The BASALT (Biologic Analog Science Associated with Lava Terrains) research program conducted Mars analog science on Earth to understand the concept of operations and capabilities needed to support these new kinds of EVAs. A suite of software tools (Minerva) was used for planning and executing all BASALT EVAs, supporting text communication across communication latency, and managing the collection of operational and scientific EVA data. This paper describes the support capabilities provided by Minerva to cope with various geospatial and temporal constraints to support the planning and execution phases of the EVAs performed during the BASALT research program. The results of this work provide insights on software needs for future science-driven planetary EVAs.


Subject(s)
Exobiology/organization & administration , Extraterrestrial Environment , Mars , Space Flight/organization & administration , Space Simulation/methods , Astronauts , Communication , Earth, Planet , Exobiology/methods , Exobiology/trends , Forecasting , Humans , Satellite Communications , Software , Space Flight/trends , Strategic Planning , Time Factors
9.
Astrobiology ; 19(3): 321-346, 2019 03.
Article in English | MEDLINE | ID: mdl-30840507

ABSTRACT

The Biologic Analog Science Associated with Lava Terrains (BASALT) research project is investigating tools, techniques, and strategies for conducting Mars scientific exploration extravehicular activity (EVA). This has been accomplished through three science-driven terrestrial field tests (BASALT-1, BASALT-2, and BASALT-3) during which the iterative development, testing, assessment, and refinement of concepts of operations (ConOps) and capabilities were conducted. ConOps are the instantiation of operational design elements that guide the organization and flow of personnel, communication, hardware, software, and data products to enable a mission concept. Capabilities include the hardware, software, data products, and protocols that comprise and enable the ConOps. This paper describes the simulation quality and acceptability of the Mars-forward ConOps evaluated during BASALT-2. It also presents the level of mission enhancement and acceptability of the associated Mars-forward capabilities. Together, these results inform science operations for human planetary exploration.


Subject(s)
Exobiology/methods , Extravehicular Activity , Mars , Operations Research , Space Simulation/methods , Exobiology/instrumentation , Humans , Space Simulation/instrumentation
10.
Astrobiology ; 19(3): 387-400, 2019 03.
Article in English | MEDLINE | ID: mdl-30840508

ABSTRACT

During the BASALT research program, real (nonsimulated) geological and biological science was accomplished through a series of extravehicular activities (EVAs) under simulated Mars mission conditions. These EVAs were supported by a Mission Support Center (MSC) that included an on-site, colocated Science Support Team (SST). The SST was composed of scientists from a variety of disciplines and operations researchers who provided scientific and technical expertise to the crew while each EVA was being conducted (intra-EVA). SST management and organization developed under operational conditions that included Mars-like communication latencies, bandwidth constraints, and EVA plans that were infused with Mars analog field science objectives. This paper focuses on the SST workspace considerations such as science team roles, physical layout, communication interactions, operational techniques, and work support technology. Over the course of BASALT field deployments to Idaho and Hawai'i, the SST team made several changes of note to increase both productivity and efficiency. For example, new roles were added for more effective management of technical discussions, and the layout of the SST workspace evolved multiple times during the deployments. SST members' reflexive adjustments resulted in a layout that prioritized face-to-face discussions over face-to-data displays, highlighting the importance of interpersonal communication during SST decision-making. In tandem with these workspace adjustments, a range of operational techniques were developed to help the SST manage discussions and information flow under time pressure.


Subject(s)
Astronauts/psychology , Extravehicular Activity , Mars , Space Simulation/methods , Communication , Decision Making , Decision Support Techniques , Efficiency , Hawaii , Humans , Idaho , Interpersonal Relations , Satellite Communications , Space Simulation/psychology
11.
Astrobiology ; 19(6): 730-756, 2019 06.
Article in English | MEDLINE | ID: mdl-30810338

ABSTRACT

The surface conditions on the Moon are extremely harsh with high doses of ultraviolet (UV) irradiation (26.8 W · m-2 UVC/UVB), wide temperature extremes (-171°C to 140°C), low pressure (10-10 Pa), and high levels of ionizing radiation. External spacecraft surfaces on the Moon are generally >100°C during daylight hours and can reach as high as 140°C at local noon. A Lunar Microbial Survival (LMS) model was developed that estimated (1) the total viable bioburden of all spacecraft landed on the Moon as ∼4.57 × 1010 microbial cells/spores at contact, (2) the inactivation kinetics of Bacillus subtilis spores to vacuum as approaching -2 logs per 2107 days, (3) the inactivation of spores on external surfaces due to concomitant low-pressure and high-temperature conditions as -6 logs per 8 h for local noon conditions, and (4) the ionizing radiation by solar wind particles as approaching -3 logs per lunation on external surfaces only. When the biocidal factors of solar UV, vacuum, high-temperature, and ionizing radiation were combined into an integrated LMS model, a -231 log reduction in viable bioburden was predicted for external spacecraft surfaces per lunation at the equator. Results indicate that external surfaces of landed or crashed spacecraft are unlikely to harbor viable spores after only one lunation, that shallow internal surfaces will be sterilized due to the interactive effects of vacuum and thermal cycling from solar irradiation, and that deep internal surfaces would be affected only by vacuum with a degradation rate of -0.02 logs per lunation.


Subject(s)
Bacillus subtilis/physiology , Microbial Viability/radiation effects , Models, Biological , Moon , Space Simulation/methods , Bacillus subtilis/radiation effects , Cosmic Radiation/adverse effects , Extraterrestrial Environment , Hot Temperature , Spacecraft , Spores, Bacterial/physiology , Spores, Bacterial/radiation effects , Ultraviolet Rays/adverse effects , Vacuum
12.
Astrobiology ; 18(7): 934-954, 2018 07.
Article in English | MEDLINE | ID: mdl-30035643

ABSTRACT

Ancient hydrothermal systems are a high-priority target for a future Mars sample return mission because they contain energy sources for microbes and can preserve organic materials (Farmer, 2000 ; MEPAG Next Decade Science Analysis Group, 2008 ; McLennan et al., 2012 ; Michalski et al., 2017 ). Characterizing these large, heterogeneous systems with a remote explorer is difficult due to communications bandwidth and latency; such a mission will require significant advances in spacecraft autonomy. Science autonomy uses intelligent sensor platforms that analyze data in real-time, setting measurement and downlink priorities to provide the best information toward investigation goals. Such automation must relate abstract science hypotheses to the measurable quantities available to the robot. This study captures these relationships by formalizing traditional "science traceability matrices" into probabilistic models. This permits experimental design techniques to optimize future measurements and maximize information value toward the investigation objectives, directing remote explorers that respond appropriately to new data. Such models are a rich new language for commanding informed robotic decision making in physically grounded terms. We apply these models to quantify the information content of different rover traverses providing profiling spectroscopy of Cuprite Hills, Nevada. We also develop two methods of representing spatial correlations using human-defined maps and remote sensing data. Model unit classifications are broadly consistent with prior maps of the site's alteration mineralogy, indicating that the model has successfully represented critical spatial and mineralogical relationships at Cuprite. Key Words: Autonomous science-Imaging spectroscopy-Alteration mineralogy-Field geology-Cuprite-AVIRIS-NG-Robotic exploration. Astrobiology 18, 934-954.


Subject(s)
Exobiology/methods , Mars , Space Simulation/methods , Exobiology/instrumentation , Models, Statistical , Robotics , Space Flight , Spacecraft , Spectrum Analysis/instrumentation , Spectrum Analysis/methods
13.
Pediatrics ; 140(1)2017 Jul.
Article in English | MEDLINE | ID: mdl-28759391

ABSTRACT

Patients with severe cystic lung disease are considered to be at risk for cyst rupture during air travel because of the possibility of increase in cyst size and impaired equilibration of pressure between the cysts and other parts of the lung. This may have clinically devastating consequences for the patient but may also result in significant costs for emergency alteration of flight schedule. We report the use of a hypobaric chamber to simulate cabin pressure changes encountered on a commercial flight to assess the safety to fly of a child with severe cystic lung disease secondary to Langerhans cell histiocytosis. The test did not result in an air leak, and the child subsequently undertook air travel without mishap. This is the first reported use of a hypobaric chamber test in a child with severe cystic lung disease. This test has the potential to be used as a fitness to fly test in children at risk for air leak syndromes who are being considered for air travel.


Subject(s)
Aerospace Medicine/methods , Histiocytosis, Langerhans-Cell/complications , Lung Diseases/complications , Space Simulation/methods , Aircraft , Child , Cysts , Humans , Hypoxia , Lung Diseases/diagnosis , Male , Risk Factors , Tomography, X-Ray Computed , Travel
14.
Aerosp Med Hum Perform ; 88(7): 641-650, 2017 Jul 01.
Article in English | MEDLINE | ID: mdl-28641681

ABSTRACT

INTRODUCTION: In commercial spaceflight, anxiety could become mission-impacting, causing negative experiences or endangering the flight itself. We studied layperson response to four varied-length training programs (ranging from 1 h-2 d of preparation) prior to centrifuge simulation of launch and re-entry acceleration profiles expected during suborbital spaceflight. We examined subject task execution, evaluating performance in high-stress conditions. We sought to identify any trends in demographics, hemodynamics, or similar factors in subjects with the highest anxiety or poorest tolerance of the experience. METHODS: Volunteers participated in one of four centrifuge training programs of varied complexity and duration, culminating in two simulated suborbital spaceflights. At most, subjects underwent seven centrifuge runs over 2 d, including two +Gz runs (peak +3.5 Gz, Run 2) and two +Gx runs (peak +6.0 Gx, Run 4) followed by three runs approximating suborbital spaceflight profiles (combined +Gx and +Gz, peak +6.0 Gx and +4.0 Gz). Two cohorts also received dedicated anxiety-mitigation training. Subjects were evaluated on their performance on various tasks, including a simulated emergency. RESULTS: Participating in 2-7 centrifuge exposures were 148 subjects (105 men, 43 women, age range 19-72 yr, mean 39.4 ± 13.2 yr, body mass index range 17.3-38.1, mean 25.1 ± 3.7). There were 10 subjects who withdrew or limited their G exposure; history of motion sickness was associated with opting out. Shorter length training programs were associated with elevated hemodynamic responses. Single-directional G training did not significantly improve tolerance. DISCUSSION: Training programs appear best when high fidelity and sequential exposures may improve tolerance of physical/psychological flight stressors. The studied variables did not predict anxiety-related responses to these centrifuge profiles.Blue RS, Bonato F, Seaton K, Bubka A, Vardiman JL, Mathers C, Castleberry TL, Vanderploeg JM. The effects of training on anxiety and task performance in simulated suborbital spaceflight. Aerosp Med Hum Perform. 2017; 88(7):641-650.


Subject(s)
Anxiety/psychology , Space Flight , Space Simulation/methods , Task Performance and Analysis , Adult , Aerospace Medicine , Aged , Centrifugation , Cohort Studies , Female , Hemodynamics , Humans , Male , Middle Aged , Motion Sickness , Prospective Studies , Space Simulation/psychology , Young Adult
15.
Aviat Space Environ Med ; 85(4): 414-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24754202

ABSTRACT

INTRODUCTION: In this study we compare two models [head-up tilt (HUT) vs. body unweighting using lower body positive pressure (LBPP)] to simulate Moon, Mars, and Earth gravities. A literature search did not reveal any comparisons of this type performed previously. We hypothesized that segmental fluid volume shifts (thorax, abdomen, upper and lower leg), cardiac output, and blood pressure (BP), heart rate (HR), and total peripheral resistance to standing would be similar in the LBPP and HUT models. METHODS: There were 21 subjects who were studied while supine (simulation of spaceflight) and standing at 100% (Earth), 40% (Mars), and 20% (Moon) bodyweight produced by LBPP in Alter-G and while supine and tilted at 80 degrees, 20 degrees, and 10 degrees HUT (analogues of Earth, Mars, and Moon gravities, respectively). RESULTS: Compared to supine, fluid shifts from the chest to the abdomen, increases in HR, and decreases in stroke volume were greater at 100% bodyweight than at reduced weights in response to both LBPP and HUT. Differences between the two models were found for systolic BP, diastolic BP, mean arterial BP, stroke volume, total peripheral resistance, and thorax and abdomen impedances, while HR, cardiac output, and upper and lower leg impedances were similar. CONCLUSIONS: Bodyweight unloading via both LBPP and HUT resulted in cardiovascular changes similar to those anticipated in actual reduced gravity environments. The LBPP model/Alter-G has the advantage of providing an environment that allows dynamic activity at reduced bodyweight; however, the significant increase in blood pressures in the Alter-GC may favor the HUT model.


Subject(s)
Cardiovascular Physiological Phenomena , Gravity, Altered , Space Simulation/methods , Adult , Blood Pressure/physiology , Cardiac Output/physiology , Female , Heart Rate/physiology , Humans , Male , Mars , Models, Cardiovascular , Moon , Orthostatic Intolerance , Posture/physiology , Space Flight , Stroke Volume/physiology , Vascular Resistance/physiology , Young Adult
16.
Aviakosm Ekolog Med ; 45(3): 24-9, 2011.
Article in Russian | MEDLINE | ID: mdl-21916247

ABSTRACT

Six male volunteers (aged 25 to 40 years) were subjects in all-round psychophysiological, hormonal and immunological studies before, in and after 105-day isolation and confinement. Blood was drawn and the 16-factorial Cattell personality inventory was filled out every 30 days. Concentrations of blood hormones, neurospecific proteins and cytokines point to a close interrelation between antibody titers to myelin-associated glycoprotein and changes in the parameters of metabolism and reproduction-related hormones, as well as cytokines and individual psychophysiology (extra-introversion, dominance, intropunitiveness, social contact selectivity, etc.), and suggest a minimum risk of demyelinizing neuropathy due to exposure to the conditions of isolation and confinement.


Subject(s)
Demyelinating Diseases/blood , Demyelinating Diseases/immunology , Myelin-Associated Glycoprotein/biosynthesis , Polyneuropathies/blood , Polyneuropathies/immunology , Social Isolation/psychology , Space Simulation/methods , Adult , Antibodies/blood , Antibodies/immunology , Cytokines/biosynthesis , Cytokines/blood , Demyelinating Diseases/diagnosis , Demyelinating Diseases/prevention & control , Hormones/biosynthesis , Hormones/blood , Humans , Immunochemistry , Male , Myelin-Associated Glycoprotein/blood , Polyneuropathies/diagnosis , Polyneuropathies/prevention & control , Regression Analysis , Risk Factors , Social Behavior , Space Flight , Surveys and Questionnaires
17.
Aviakosm Ekolog Med ; 45(1): 46-9, 2011.
Article in Russian | MEDLINE | ID: mdl-21675193

ABSTRACT

Dynamics of the gastrointestinal functioning was reconstructed by analysis of the scatological data from volunteered subjects before, on days 16, 35, 45, 60, 90 and after completion of 105-day isolation experiment. The analysis showed that scatological investigations performed in the conditions imitating life in an exploration vehicle environment are instrumental in detecting deviations in the GI function indicative of pancreas excretory and hepar biliary excretion and synthetic hypofunction that can be responsible for intestinal dysfunction. Normalization of scatological parameters following the experiment witnesses to functional genesis of the changes observed during the exploration mission simulation.


Subject(s)
Feces/chemistry , Gastrointestinal Tract/metabolism , Space Flight , Space Simulation/methods , Adult , Humans , Male , Time Factors
18.
Optom Vis Sci ; 88(9): 1119-26, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21623249

ABSTRACT

PURPOSE: To develop a model that will accurately predict the distance spherical lens correction needed to be worn by National Aeronautics and Space Administration astronauts while training underwater. The replica space suit's helmet contains curved visors that induce refractive power when submersed in water. METHODS: Anterior surface powers and thicknesses were measured for the helmet's protective and inside visors. The impact of each visor on the helmet's refractive power in water was analyzed using thick lens calculations and Zemax optical design software. Using geometrical optics approximations, a model was developed to determine the optimal distance spherical power needed to be worn underwater based on the helmet's total induced spherical power underwater and the astronaut's manifest spectacle plane correction in air. The validity of the model was tested using data from both eyes of 10 astronauts who trained underwater. RESULTS: The helmet's visors induced a total power of -2.737 D when placed underwater. The required underwater spherical correction (FW) was linearly related to the spectacle plane spherical correction in air (FAir): FW = FAir + 2.356 D. The mean magnitude of the difference between the actual correction worn underwater and the calculated underwater correction was 0.20 ± 0.11 D. The actual and calculated values were highly correlated (r = 0.971) with 70% of eyes having a difference in magnitude of <0.25 D between values. CONCLUSIONS: We devised a model to calculate the spherical spectacle lens correction needed to be worn underwater by National Aeronautics and Space Administration astronauts. The model accurately predicts the actual values worn underwater and can be applied (more generally) to determine a suitable spectacle lens correction to be worn behind other types of masks when submerged underwater.


Subject(s)
Astronauts/education , Diving , Eyeglasses/standards , Head Protective Devices , Refraction, Ocular , Space Simulation/methods , Visual Acuity , Equipment Design , Humans , Reproducibility of Results , Space Suits
19.
Aviakosm Ekolog Med ; 45(5): 24-8, 2011.
Article in Russian | MEDLINE | ID: mdl-22312857

ABSTRACT

Effect of adaptive biocontrol on efficiency of the operator possessing stable skills in simulating manual control of Soyuz hang-up and berthing to the International space station (ISS) was studied. Job quality was evaluated by the time, energy and precision parameters. The investigation used an ISS computer model and mock-ups of the board operating controls.


Subject(s)
Adaptation, Psychological , Software , Space Simulation/psychology , Spacecraft , Algorithms , Electroencephalography , Humans , Male , Middle Aged , Psychological Tests/statistics & numerical data , Space Simulation/methods
20.
Aviakosm Ekolog Med ; 45(5): 28-33, 2011.
Article in Russian | MEDLINE | ID: mdl-22312858

ABSTRACT

Light and scanning electron microscopy was used to study the morphological parameters and ultrastructure of Helix lucorum statocysts and statoliths in Pomatias rivulare statocysts after 56, 93 and 110-day exposure to microgravity aboard the ISS. Increased gravity was simulated by 30-d centrifugation at 6 g. On the first day of recovery, many statoconia and statoliths were found to carry numerous warts. Moreover, statoconia grew in number significantly as compared with the ground control. On the contrary centrifugation caused massive destruction of statoconia. In a month after orbital flight and centrifugation morphology of both statoconia and stastoliths was nearly normal. These results evidence, that the gravitational field is an important factor for the abiotic medium responsible for building up the inertial mass in the equilibrium organ of animals.


Subject(s)
Adaptation, Physiological , Gastropoda/ultrastructure , Otolithic Membrane/ultrastructure , Space Flight , Space Simulation/methods , Animals , Centrifugation/adverse effects , Female , Gastropoda/physiology , Hypergravity/adverse effects , Male , Microscopy, Electron, Scanning , Microscopy, Phase-Contrast , Otolithic Membrane/physiology , Space Simulation/instrumentation , Weightlessness/adverse effects
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