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  • facet.materialart.
    Persoonia - Molecular Phylogeny and Evolution of Fungi (1878-9080) vol.38 (2017) p.20
    Publication Date: 2016-08-25
    Description: Anthracnose caused by Colletotrichum species is a serious disease of more than 30 plant genera. Several Colletotrichum species have been reported to infect chili in different countries. Although China is the largest chiliproducing country, little is known about the species that have been infecting chili locally. Therefore, we collected samples of diseased chili from 29 provinces of China, from which 1285 strains were isolated. The morphological characters of all strains were observed and compared, and multi-locus phylogenetic analyses (ITS, ACT, CAL, CHS-1, GAPDH, TUB2, and HIS3) were performed on selected representative strains. Fifteen Colletotrichum species were identified, with C. fioriniae, C. fructicola, C. gloeosporioides, C. scovillei, and C. truncatum being prevalent. Three new species, C. conoides, C. grossum, and C. liaoningense, were recognised and described in this paper. Colletotrichum aenigma, C. cliviae, C. endophytica, C. hymenocallidis, C. incanum, C. karstii, and C. viniferum were reported for the first time from chili. Pathogenicity of all species isolated from chili was confirmed, except for C. endophytica. The current study improves the understanding of species causing anthracnose on chili and provides useful information for the effective control of the disease in China.
    Keywords: DNA phylogeny ; multi-gene analysis ; plant pathogen ; systematics
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • Publication Date: 2016-08-25
    Description: Phialophora as defined by its type species P. verrucosa is a genus of Chaetothyriales, and a member of the group known as ‘black yeasts and relatives’. Phialophora verrucosa has been reported from mutilating human infections such as chromoblastomycosis, disseminated phaeohyphomycosis and mycetoma, while morphologically similar fungi are rather commonly isolated from the environment. Phenotypes are insufficient for correct species identification, and molecular data have revealed significant genetic variation within the complex of species currently identified as P. verrucosa or P. americana. Multilocus analysis of 118 strains revealed the existence of five reproductively isolated species apparently having different infectious potentials. Strains of the sexual morph Capronia semiimmersa cluster within P. americana. The newly defined taxa differ markedly in their predilection for the human host.
    Keywords: Chaetothyriales ; chromoblastomycosis ; phaeohyphomycosis ; Phialophora ; phylogeny ; taxonomy
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • Publication Date: 2016-07-13
    Description: Providing adequate washout of carbon dioxide (CO2) from within a space suit helmet is essential to maintaining a safe operating environment for astronauts using space suits. A valid and reliable method for quantification of inspired CO2 inside space suits is required to ensure the health and performance of suited crewmembers. With this objective, several different methods for measuring the concentration of CO2 in a space suit helmet were evaluated. A nasal cannula was compared with respirator style masks worn by suited test subjects, with air drawn into gas analyzers to measure the concentration of CO2 in the immediate vicinity of the mouth and nose. The respirator style masks, some being commercially available products and some novel designs, did not provide repeatable results based on initial pilot testing in three subjects. Based on the analysis of those studies, the decision was made to down-select to a commercially available nasal cannula as the primary sampling device to be used in follow-on testing in the MKIII (n = 8) and Z2 (n = 6) prototype space suits, with five subjects performing tests in both suits allowing for repeated measures comparisons. Subjects were tasked with achieving target metabolic rates of 293, 586, and 879 Watts (1000, 2000, and 3000 BTU/h) and at air supply flow rates of 3.4, 6.8, and 10.2 Am(sup 3)/hr. (2, 4, and 6 ACFM). Each test condition was performed twice; once with subjects instructed to breathe however they felt comfortable, and once with subjects instructed to breathe only through their nose. Inspired CO2 values were determined by the lowest points, or troughs, within each breath of the respiratory trace. This method provides multiple inspired CO2 samples at known metabolic rates for each test condition and provides a larger data set for analysis than possible through gross averaging of the minimum inspired CO2. Results indicate that reliable measures are achievable under both breathing conditions but that restricting subjects to breathing only through their nose provides for less variable CO2 measurements breath to breath, within +/- 66.7 Pa CO2 (+/- 0.5 mmHg) at a 95% confidence level than when breathing unrestricted, which resulted in +/- 173.3 Pa CO2 (+/- 1.3 mmHg) variability with 95% confidence. However, during normal operation of a space suit it is not realistic to enforce or monitor the breathing style of the crewmember and, although restricted breathing is reliable, it is not known whether measurement of inspired CO2 during nose-only breathing is valid for evaluation of a space suit washout. To verify that one or both of the breathing style nasal cannula sampling methods provide a valid inspired CO2 measurement, testing is planned in an environmental chamber during which the ambient CO2 concentration will be controlled. A nasal cannula will be worn by unsuited subjects and measurements will be taken under both restricted and unrestricted breathing conditions across a range of metabolic rates during which nasal cannula CO2 concentration measures will be compared against the ambient value.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-36598 , IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-07-01
    Description: NASA's human space program has developed considerable experience with near Earth space operations. Although NASA has experience with deep space robotic missions, NASA has little substantive experience with human deep space operations. Even in the Apollo program, the missions lasted only a few weeks and the communication latencies were on the order of seconds. Human missions beyond the relatively close confines of the Earth-Moon system will involve missions with durations measured in months and communications latencies measured in minutes. To minimize crew risk and to maximize mission success, NASA needs to develop a better understanding of the implications of these types of mission durations and communication latencies on vehicle design, mission design and flight controller interaction with the crew. To begin to address these needs, NASA performed a study using a physics-based subsystem simulation to investigate the interactions between spacecraft crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation, built with a subsystem modeling tool developed at NASA's Johnson Space Center, models the life support system of a Mars transit vehicle. The simulation contains models of the cabin atmosphere and pressure control system, electrical power system, drinking and waste water systems, internal and external thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the vehicle subsystems; 2) a mission control center interface with data transport delays up to 15 minutes each way; 3) a real-time simulation test conductor interface that can be use to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission between July 18th and Aug 3rd of year 2016. The NEEMO mission provides ideal conditions for this study with crew in the loop, an active control center, and real-time flow of high latency communications and data. NEEMO crew and ground support will work through procedures including activation of the transit vehicle power system, opening the hatch between the transit vehicle and a Mars ascent vehicle, transferring simulated crewmembers between vehicles, overcoming subsystem malfunctions, sending simulated crewmember on extra-vehicular activities, and other housekeeping activities. This study is enhancing the understanding of high latency operations and the advantages and disadvantages of different communication methods. It is also providing results that will help improve the design of simulation interfaces and inform the design of Mars transit vehicles.
    Keywords: Ground Support Systems and Facilities (Space) ; Space Communications, Spacecraft Communications, Command and Tracking
    Type: JSC-CN-36600 , IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-07-01
    Description: An over-arching goal of the multi-year Biologic Analog Science Associated with Lava Terrains (BASALT) project is to iteratively develop, implement, and evaluate concepts of operations (ConOps) and supporting capabilities intended to enable and enhance human exploration of Mars. Geological and biological scientific fieldwork is being conducted during four total deployments at two high-fidelity Mars analogs, all within simulated Mars mission conditions that are based on current architectural assumptions for Mars exploration missions. Specific capabilities being evaluated include the use of mobile science platforms, extravehicular informatics, communication and navigation packages, advanced science mission planning tools, and scientifically-relevant instrument packages to achieve the project goals. This paper describes the planning, execution, and results of the first field deployment, referred to as BASALT 1, which consisted of a series of 12 simulated extravehicular activities (EVAs) on the lava terrains of Craters of the Moon, Idaho. Scientific objectives of the EVAs related to determination of how microbial communities and habitability correlate with the physical and geochemical characteristics of chemically-altered basalt environments. The concept of operations (ConOps) and capabilities deployed and tested during BASALT 1 were based on extensive data from previous NASA trade studies and analog testing, and the primary research question was whether those ConOps and capabilities would work acceptably when performing real (non-simulated) biological and geological scientific exploration under four different communication scenarios. Specifically, communication latencies of 5 and 15 minutes one-way light time (OWLT) were tested; these delays fall within the range of 4 to 22 minute OWLT delays that would be experienced during a Mars mission. Science operations were also conducted under low bandwidth conditions (0.512 Mb/s uplink, 1.54 Mb/s downlink), representing a conservative and affordable flight data rate, and a higher bandwidth case (5.0 Mb/s uplink, 10.0 Mb/s downlink), representing an upgraded human mission capability that would require additional infrastructure and technology development. In all conditions, two EVA crewmembers communicated with two intravehicular (IV) crewmembers with high bandwidth and near-zero communication latency, simulating communication among crewmembers on Mars. EVA crewmembers wore simulated EVA informatics backpacks including communication systems, position tracking, hand-held field spectrometers, cameras, and sample collection tools. Bidirectional communication between crewmembers ("Mars") and a Mission Support Center ("Earth"), staffed by a team of science and operations experts, was subject to the aforementioned latency and bandwidth constraints. This paper presents the synthesized results of the BASALT 1 deployment with respect to ConOps and capabilities assessment. Evaluation of the ConOps and capabilities was accomplished through a combination of network analytical data, completion of scientific objectives, ethnographic observations, planned versus actual timeline data, and collection of subjective ratings and comments using the same methodology employed during multiple previous NASA analog tests. In addition to assessing the acceptability of the ConOps and capabilities from scientific and operational perspectives, the extent to which specific capabilities enabled or enhanced the science operations was also evaluated. These data will provide a basis for prioritization of capability development for future BASALT deployments and, ultimately, future human exploration missions.
    Keywords: Man/System Technology and Life Support ; Space Transportation and Safety
    Type: JSC-CN-36610 , IEEE Aerospace Conference 2017; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-06-15
    Description: In the proposed paper, the optimal design of reference strain structures (RSS) will be performed targeting for the accurate observation of the dynamic bending and torsion deformation of a flexible rocket. It will provide the detailed description of the finite-element (FE) model of a notional flexible rocket created in MSC.Patran. The RSS will be attached longitudinally along the side of the rocket and to track the deformation of the thin-walled structure under external loads. An integrated surrogate-based multi-objective optimization approach will be developed to find the optimal design of the RSS using the FE model. The Kriging method will be used to construct the surrogate model. For the data sampling and the performance evaluation, static/transient analyses will be performed with MSC.Natran/Patran. The multi-objective optimization will be solved with NSGA-II to minimize the difference between the strains of the launch vehicle and RSS. Finally, the performance of the optimal RSS will be evaluated by checking its strain-tracking capability in different numerical simulations of the flexible rocket.
    Keywords: Structural Mechanics ; Launch Vehicles and Launch Operations
    Type: KSC-E-DAA-TN32305 , AIAA SciTech Conference; 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-08-18
    Description: One of the biggest challenges facing NASA's deep space exploration goals is structural mass. A long duration transit vehicle on a journey to Mars, for example, requires a large internal volume for cargo, supplies and crew support. As with all space structures, a large pressure vessel is not enough. The vehicle also requires thermal, micro-meteoroid, and radiation protection, a navigation and control system, a propulsion system, and a power system, etc. As vehicles get larger, their associated systems also get larger and more complex. These vehicles require larger lift capacities and force the mission to become extremely costly. In order to build large volume habitable vehicles, with only minimal increases in launch volume and mass, NASA is developing lightweight structures. Lightweight structures are made from non-metallic materials including graphite composites and high strength fabrics and could provide similar or better structural capability than metals, but with significant launch volume and mass savings. Fabric structures specifically, have been worked by NASA off and on since its inception, but most notably in the 1990's with the TransHAB program. These TransHAB developed structures use a layered material approach to form a pressure vessel with integrated thermal and micro-meteoroid and orbital debris (MMOD) protection. The flexible fabrics allow the vessel to be packed in a small volume during launch and expand into a much larger volume once in orbit. NASA and Bigelow Aerospace recently installed the first human-rated inflatable module on the International Space Station (ISS), known as the Bigelow Expandable Activity Module (BEAM) in May of 2016. The module provides a similar internal volume to that of an Orbital ATK Cygnus cargo vehicle, but with a 77% launch volume savings. As lightweight structures are developed, testing methods are vital to understanding their behavior and validating analytical models. Common techniques can be applied to fabric materials, such as tensile testing, fatigue testing, and shear testing, but common measurement techniques cannot be used on fabric. Measuring strain in a material and during a test is a critical parameter for an engineer to monitor the structure during the test and correlate to an analytical model. The ability to measure strain in fabric structures is a challenge for NASA. Foil strain gauges, for example, are commonplace on metallic structures testing, but are extremely difficult to interface with a fabric substrate. New strain measuring techniques need to be developed for use with fabric structures. This paper investigates options for measuring strain in fabric structures for both ground testing and in-space structural health monitoring. It evaluates current commercially available options and outlines development work underway to build custom measurement solutions for NASA's fabric structures.
    Keywords: Instrumentation and Photography
    Type: JSC-CN-36506 , AIAA SciTech; 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-07-13
    Description: Human exploration of Mars will involve both crewed and robotic systems. Many mission concepts involve the deployment and assembly of mission support assets prior to crew arrival on the surface. Some of these deployment and assembly activities will be performed autonomously while others will be performed using teleoperations. However, significant communications latencies between the Earth and Mars make teleoperations challenging. Alternatively, low latency teleoperations are possible from locations in Mars orbit like Mars' moons Phobos and Deimos. To explore these latency opportunities, NASA is conducting a series of studies to investigate the effects of latency on telerobotic deployment and assembly activities. These studies are being conducted in laboratory environments at NASA's Johnson Space Center (JSC), the Human Exploration Research Analog (HERA) at JSC and the NASA Extreme Environment Mission Operations (NEEMO) underwater habitat off the coast of Florida. The studies involve two human-in-the-loop interactive simulations developed by the NASA Exploration Systems Simulations (NExSyS) team at JSC. The first simulation investigates manipulation related activities while the second simulation investigates mobility related activities. The first simulation provides a simple real-time operator interface with displays and controls for a simulated 6 degree of freedom end effector. The initial version of the simulation uses a simple control mode to decouple the robotic kinematic constraints and a communications delay to model latency effects. This provides the basis for early testing with more detailed manipulation simulations planned for the future. Subjects are tested using five operating latencies that represent teleoperation conditions from local surface operations to orbital operations at Phobos, Deimos and ultimately high Martian orbit. Subject performance is measured and correlated with three distance-to-target zones of interest. Each zone represents a target distance ranging from beyond 10m in Zone 1, through 1 cm to contact in Zone 5 with a step size factor of 10. Collected data consists of both objective simulation data (time, distance, hand controller inputs, velocity) and subjective questionnaire data. The second simulation provides a simple real-time operator interface with displays and control of a simulated surface rover. The rover traverses a synthetic Mars-like terrain and must be maneuvered to avoid obstacles while progressing to its destination. Like the manipulator simulation, subjects are tested using five operating latencies that represent teleoperation conditions from local surface operations to orbital operations at Phobos, Deimos and ultimately high Martian orbit. The rover is also operated at three different traverse speeds to assess the correlation between latency and speed. Collected data consisted of both objective simulation data (time, distance, hand controller inputs, braking) and subjective questionnaire data. These studies are exploring relationships between task complexity, operating speeds, operator efficiencies, and communications latencies for low latency teleoperations in support of human planetary exploration. This paper presents early results from these studies along with the current observations and conclusions. These and planned future studies will help to inform NASA on the potential for low latency teleoperations to support human exploration of Mars and inform the design of robotic systems and exploration missions.
    Keywords: Ground Support Systems and Facilities (Space) ; Lunar and Planetary Science and Exploration
    Type: JSC-CN-36630 , IEEE Aerospace Conference 2017; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-06-09
    Description: Flying a mission in space requires a massive commitment of resources, and without the talent and commitment of the people involved in this effort we would never leave the atmosphere of Earth. When we use the phrase "humans in the loop", it could apply to almost any endeavor since everything starts with humans developing a concept, completing the design process, building or implementing a product and using the product to achieve a goal or purpose. Narrowing the focus to spaceflights, there are a variety of individuals involved throughout the preparations for flight and the flight itself. All of the humans involved add value and support for program success. The purpose of this paper focuses on how a Probabilistic Risk Assessment (PRA) accounts for the human in the loop for potential missions using a technique called Human Reliability Analysis (HRA). Human actions can increase or decrease the overall risk via initiating events or mitigating them, thus removing the human from the loop doesn't always lower the risk.
    Keywords: Quality Assurance and Reliability
    Type: JSC-CN-36503 , AIAA Science & Technology Forum & Exposition (SciTech 2017); 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-07-15
    Description: NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. A mission was undertaken in 2016, NEEMO 21. The mission was performed at the Aquarius undersea research habitat. During the mission, the effects of varying operations concepts on representative communication latencies associated with Mars missions were studied. Six subjects were weighed out to simulate near-zero or partial gravity and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) to provide input and direction during exploration activities. Exploration traverses were planned in advance based on precursor data collected. Subjects completed science-related tasks including pre-sampling surveys and marine science-based sampling as a portion of their tasks on saturation dives up to 4 hours in duration that were to simulate extravehicular activity (EVA) on Mars. A one-way communication latency of 15 minutes between space and mission control was simulated throughout the missions. Objective data included task completion times, total EVA times, crew idle time, translation time, SBT assimilation time (defined as time available for ST to discuss data/imagery after it has been collected, in addition to the time taken to watch imagery and listen to audio streaming over latency). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. Results were collected and will be presented on the acceptability of the operations concepts studied and which capabilities are the most enabling/enhancing in the operations concept. Discussion is presented on the importance of designing EVA timelines to account for the length of the task, level of interaction with the ground that is required/desired, and communication latency.
    Keywords: Lunar and Planetary Science and Exploration
    Type: JSC-CN-36634 , IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT ; United States
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  • Publication Date: 2016-04-19
    Description: NASA uses two HRA assessment methodologies. The first is a simplified method which is based on how much time is available to complete the action, with consideration included for environmental and personal factors that could influence the human's reliability. This method is expected to provide a conservative value or placeholder as a preliminary estimate. This preliminary estimate is used to determine which placeholder needs a more detailed assessment. The second methodology is used to develop a more detailed human reliability assessment on the performance of critical human actions. This assessment needs to consider more than the time available, this would include factors such as: the importance of the action, the context, environmental factors, potential human stresses, previous experience, training, physical design interfaces, available procedures/checklists and internal human stresses. The more detailed assessment is still expected to be more realistic than that based primarily on time available. When performing an HRA on a system or process that has an operational history, we have information specific to the task based on this history and experience. In the case of a PRA model that is based on a new design and has no operational history, providing a "reasonable" assessment of potential crew actions becomes more problematic. In order to determine what is expected of future operational parameters, the experience from individuals who had relevant experience and were familiar with the system and process previously implemented by NASA was used to provide the "best" available data. Personnel from Flight Operations, Flight Directors, Launch Test Directors, Control Room Console Operators and Astronauts were all interviewed to provide a comprehensive picture of previous NASA operations. Verification of the assumptions and expectations expressed in the assessments will be needed when the procedures, flight rules and operational requirements are developed and then finalized.
    Keywords: Quality Assurance and Reliability
    Type: JSC-CN-36101 , Annual Reliability and Maintainability Symposium; 23-26 Jan. 2017; Orlando, FL; United States
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  • Publication Date: 2016-07-26
    Description: Unstructured grid solvers have well-known issues predicting surface heat fluxes when strong shocks are present. Various efforts have been made to address the underlying numerical issues that cause the erroneous predictions. The present work addresses some of the shortcomings of unstructured grid solvers, not by addressing the numerics, but by applying structured grid best practices to unstructured grids. A methodology for robust shock detection and shock fitting is outlined and applied to production relevant cases. Results achieved by using the Loci-CHEM Computational Fluid Dynamics solver are provided.
    Keywords: Fluid Mechanics and Thermodynamics
    Type: JSC-CN-36483 , AIAA SciTech 2017; 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-09-16
    Description: Based on molecular and morphological data we investigated the taxonomy and phylogeny of the ectomycorrhizal genus Tricholoma in northern Europe. Our phylogenetic tree confirmed the presence of at least 72 well circumscribed species within the region. Of these, three species, viz. T. boreosulphurescens, T. bryogenum and T. ilkkae are described as new to science, based on morphological, distributional, ecological and molecular data. Several other terminal branches represent putative cryptic taxa nested within classical species or species groups. Molecular type studies and/or designation of sequenced neotypes are needed in these groups, before the taxonomy can be settled. In general our phylogenetic analysis supported previous suprageneric classification systems, but with some substantial changes. Most notably, T. virgatum and allies were found to belong to sect. Tricholoma rather than sect. Atrosquamosa, while T. focale was found to be clearly nested in sect. Genuina rather than in sect. Caligata. In total, ten sections are accepted, with five species remaining unassigned. The combination of morphological and molecular data showed pileus colour, pileipellis structure, presence of clamp connections and spore size to be rather conservative characters within accepted sections, while the presence of a distinct ring, and especially host selection were highly variable within these.
    Keywords: Agarics ; biogeography ; cryptic species ; ectomycorrhizal fungi ; host selection ; morphological traits ; phylogeny ; Tricholomataceae
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • Publication Date: 2016-09-16
    Description: Infrageneric relations of the genetically diverse milkcap genus Lactifluus (Russulales, Basidiomycota) are poorly known. Currently used classification systems still largely reflect the traditional, mainly morphological, characters used for infrageneric delimitations of milkcaps. Increased sampling, combined with small-scale molecular studies, show that this genus is underexplored and in need of revision. For this study, we assembled an extensive dataset of the genus Lactifluus, comprising 80 % of all known species and 30 % of the type collections. To unravel the infrageneric relationships within this genus, we combined a multi-gene molecular phylogeny, based on nuclear ITS, LSU, RPB2 and RPB1, with a morphological study, focussing on five important characteristics (fruit body type, presence of a secondary velum, colour reaction of the latex/context, pileipellis type and presence of true cystidia). Lactifluus comprises four supported subgenera, each containing several supported clades. With extensive sampling, ten new clades and at least 17 new species were discovered, which highlight the high diversity in this genus. The traditional infrageneric classification is only partly maintained and nomenclatural changes are proposed. Our morphological study shows that the five featured characteristics are important at different evolutionary levels, but further characteristics need to be studied to find morphological support for each clade. This study paves the way for a more detailed investigation of biogeographical history and character evolution within Lactifluus.
    Keywords: milkcaps ; molecular evolution ; morphology ; taxonomy
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • Publication Date: 2016-09-23
    Description: This paper presents the design and development of a friction-based coupling device for a fiber-optic monitoring system that can be deployed on existing subsea structures. This paper provides a summary of the design concept, prototype development, prototype performance testing, and design refinements of the device. The results of the laboratory testing of the first prototype performed at the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) are included in this paper. Limitations of the initial design were identified and future design improvements were proposed. These new features will enhance the coupling of the device and improve the monitoring system measurement capabilities. A major challenge of a post-installed instrumentation monitoring system is to ensure adequate coupling between the instruments and the structure of interest for reliable measurements. Friction-based coupling devices have the potential to overcome coupling limitations caused by marine growth and soil contamination on subsea structures, flowlines or risers. The work described in this paper investigates the design of a friction-based coupling device (friction clamp), which is applicable for pipelines and structures that are suspended in the water column and those that are resting on the seabed. The monitoring elements consist of fiber-optic sensors that are bonded to a metal clamshell with a high-friction coating. The friction clamp has a single hinge design to facilitate the operation of the clamp and dual rows of opposing fasteners to distribute the clamping force on the structure. The friction clamp can be installed by divers in shallow depths or by remotely operated vehicles in deep-water applications. NASA-JSC was involved in the selection and testing of the friction coating, and in the design and testing of the prototype clamp device. Four-inch diameter and eight-inch diameter sub-scale friction clamp prototypes were built and tested to evaluate the strain measuring capabilities of the design under different loading scenarios. The testing revealed some limitations of the initial design concept, and subsequent refinements were explored to improve the measurement performance of the system. This study was part of a collaboration between NASA-JSC and Astro Technology, Inc. within a study called Clear Gulf. The primary objective of the Clear Gulf study is to develop advanced instrumentation technologies that will improve operational safety and reduce the risk of hydrocarbon spillage. NASA provided unique insights, expansive test facilities, and technical expertise to advance these technologies that would benefit the environment, the public, and commercial industries.
    Keywords: Mechanical Engineering
    Type: JSC-CN-37503 , International Conference on Ocean Offshore & Artic Engineering (OMAE); 25-30 Jun. 2017; Trondheim; Norway
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  • Publication Date: 2016-09-17
    Description: The astronaut community is unique, and may be disproportionately exposed to occupational hazards not commonly seen in other communities. The extent to which the demands of the astronaut occupation and exposure to spaceflight-related hazards affect the health of the astronaut population over the life course is not completely known. A better understanding of the individual, population, and mission impacts of astronaut occupational exposures is critical to providing clinical care, targeting occupational surveillance efforts, and planning for future space exploration. The ability to characterize the risk of latent health conditions is a significant component of this understanding. Provision of health screening services to active and former astronauts ensures individual, mission, and community health and safety. Currently, the NASA-Johnson Space Center (JSC) Flight Medicine Clinic (FMC) provides extensive medical monitoring to active astronauts throughout their careers. Upon retirement, astronauts may voluntarily return to the JSC FMC for an annual preventive exam. However, current retiree monitoring includes only selected screening tests, representing an opportunity for augmentation. The potential long-term health effects of spaceflight demand an expanded framework of testing for former astronauts. The need is two-fold: screening tests widely recommended for other aging populations are necessary to rule out conditions resulting from the natural aging process (e.g., colonoscopy, mammography); and expanded monitoring will increase NASA's ability to better characterize conditions resulting from astronaut occupational exposures. To meet this need, NASA has begun an extensive exploration of the overall approach, cost, and policy implications of e an Astronaut Occupational Health program to include expanded medical monitoring of former NASA astronauts. Increasing the breadth of monitoring services will ultimately enrich the existing evidence base of occupational health risks to astronauts. Such an expansion would therefore improve the understanding of the health of the astronaut population as a whole, and the ability to identify, mitigate, and manage such risks in preparation for deep space exploration missions.
    Keywords: Aerospace Medicine ; Life Sciences (General)
    Type: JSC-CN-37271 , International Conference on Occupational Health and Safety (ICOHS 2017); 9-10 Mar. 2017; Miami, FL; United States
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  • Publication Date: 2016-09-28
    Description: INTRODUCTION: The increase in the alveolar-arterial oxygen (O2) partial pressure gradient during increasing hypoxia may further increase in microgravity (microG). METHODS: Four male astronauts on STS-69 (1995) and 4 on STS-72 (1996) submitted to an acute sequential hypoxic challenge by breathing for 4 minutes at 18.0%, 14.9%, 13.5%, 12.9%, and 12.2% O2 - balance nitrogen at sea level. The 18.0% O2 mixture was equivalent to an inspired O2 partial pressure (PIO2) of 127 mm Hg when exposed to 527 mm Hg while breathing 26.5% O2 for several days in G. A Novametrix CO2SMO Model 7100 recorded heart rate (HR, beats min-1) and hemoglobin (Hb) O2 saturation through finger pulse oximetry (SpO2, %), end-tidal carbon dioxide partial pressure (PETCO2, mm Hg), and respiration rate (RR, breaths/min) through an infrared capnograph positioned in a mouthpiece. Measurements were also taken the day of return to Earth (R+0) and at R+2. Linear mixed effects models assessed changes in SpO2 after exposure to microG. Interactions between measurement condition and available physiologic measurements were also explored. RESULTS: Astronaut SpO2 levels at baseline, R+0, and R+2 were not significantly different from in flight, about 97% given a PIO2 of 127 mm Hg. There was no difference in astronaut SpO2 levels between baseline and R+0 or R+2 over the hypoxic challenge. Additionally, no significant interactions were identified. CONCLUSIONS: While microG did not affect astronaut Hb O2 saturation in this study, large within- and between-subject variability in SpO2 at increasingly hypoxic doses require a deeper understanding of subject-specific factors that influence O2 transfer onto Hb.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37563 , AsMA Annual Scientific Meeting ; 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-10-05
    Description: No abstract available
    Keywords: Quality Assurance and Reliability
    Type: JSC-CN-37493-2 , RAMS 2014: The Annual Reliability and Maintainability Symposium ; 23-27 Jan 2017; Orlando, FL; United States
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  • Publication Date: 2016-10-05
    Description: Management guidelines were created to screen and manage asymptomatic renal stones in U.S. astronauts. The true risk for renal stone formation in astronauts due to the space flight environment is unknown. Proper management of this condition is crucial to mitigate health and mission risks. The NASA Flight Medicine Clinic electronic medical record and the Lifetime Surveillance of Astronaut Health databases were reviewed. An extensive review of the literature and current aeromedical standards for the monitoring and management of renal stones was also done. This work was used to develop a screening and management protocol for renal stones in astronauts that is relevant to the spaceflight operational environment. In the proposed guidelines all astronauts receive a yearly screening and post-flight renal ultrasound using a novel ultrasound protocol. The ultrasound protocol uses a combination of factors, including: size, position, shadow, twinkle and dispersion properties to confirm the presence of a renal calcification. For mission-assigned astronauts, any positive ultrasound study is followed by a low-dose renal computed tomography scan and urologic consult. Other specific guidelines were also created. A small asymptomatic renal stone within the renal collecting system may become symptomatic at any time, and therefore affect launch and flight schedules, or cause incapacitation during a mission. Astronauts in need of definitive care can be evacuated from the International Space Station, but for deep space missions evacuation is impossible. The new screening and management algorithm has been implemented and the initial round of screening ultrasounds is under way. Data from these exams will better define the incidence of renal stones in U.S. astronauts, and will be used to inform risk mitigation for both short and long duration spaceflights.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37560 , Aerospace Medical Association Scientific Meeting (AsMA); 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-10-05
    Description: NASA (National Aeronautics and Space Administration) Johnson Space Center (JSC) Safety and Mission Assurance (S&MA) uses two human reliability analysis (HRA) methodologies. The first is a simplified method which is based on how much time is available to complete the action, with consideration included for environmental and personal factors that could influence the human's reliability. This method is expected to provide a conservative value or placeholder as a preliminary estimate. This preliminary estimate or screening value is used to determine which placeholder needs a more detailed assessment. The second methodology is used to develop a more detailed human reliability assessment on the performance of critical human actions. This assessment needs to consider more than the time available, this would include factors such as: the importance of the action, the context, environmental factors, potential human stresses, previous experience, training, physical design interfaces, available procedures/checklists and internal human stresses. The more detailed assessment is expected to be more realistic than that based primarily on time available. When performing an HRA on a system or process that has an operational history, we have information specific to the task based on this history and experience. In the case of a Probabilistic Risk Assessment (PRA) that is based on a new design and has no operational history, providing a "reasonable" assessment of potential crew actions becomes more challenging. To determine what is expected of future operational parameters, the experience from individuals who had relevant experience and were familiar with the system and process previously implemented by NASA was used to provide the "best" available data. Personnel from Flight Operations, Flight Directors, Launch Test Directors, Control Room Console Operators, and Astronauts were all interviewed to provide a comprehensive picture of previous NASA operations. Verification of the assumptions and expectations expressed in the assessments will be needed when the procedures, flight rules, and operational requirements are developed and then finalized.
    Keywords: Quality Assurance and Reliability
    Type: JSC-CN-37493-1 , RAMS 2017: The Annual Reliability and Maintainability Symposium; 23-26 Jan. 2017; Orlando, FL; United States
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  • facet.materialart.
    Persoonia - Molecular Phylogeny and Evolution of Fungi (1878-9080) vol.38 (2017) p.81
    Publication Date: 2016-10-07
    Description: Isolates of Teratosphaeriaceae have frequently been found in the integument of attine ants, proving to be common and diverse in this microenvironment. The LSU phylogeny of the ant-isolated strains studied revealed that they cluster in two main lineages. The first was associated with the genus Xenopenidiella whereas the other represented two ant-isolated lineages sister to the taxa Penidiella aggregata and P. drakensbergensis, which are allocated to the new genus Penidiellomyces. The genus Penidiella is limited to the lineage containing P. columbiana, which is not congeneric with Penidiellomyces or Penidiellopsis, nor with Simplicidiella, a novel genus introduced here to accommodate a strain isolated from ants. For species level analysis, the final 26 aligned sequences of the ITS (498 characters), cmdA (389 characters), tef1 (342 characters) and tub2 (446 characters) gene regions lead to the introduction of six new species in Xenopenidiella, and one in respectively Penidiellopsis and Simplicidiella. The species described in this study were distinguished by the combination of morphological and phylogenetic data. Novelties on the integument of leaf-cutting ants from Brazil include: Penidiellopsis ramosus, Xenopenidiella clavata, X. formica, X. inflata, X. laevigata, X. nigrescens, X. tarda spp. nov., and Simplicidiella nigra gen. & sp. nov. Beta-tubulin is recommended as primary barcode for the distinction of species in Penidiellopsis, whereas ITS was sufficient to distinguish species of Xenopenidiella.
    Keywords: Attini tribe ; leaf-cutting ants ; multi-gene analyses ; systematics ; Xenopenidiella
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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    Communications in Nonlinear Science and Numerical Simulation
    Publication Date: 2016-10-06
    Description: We study synchronization properties of three nonlinearly coupled chaotic maps. Coupling is introduced in such a way, that it cannot be reduced to pairwise terms, but includes combined action of all interacting units. For two models of nonlinear coupling we characterize the transition to complete synchrony, as well as partially synchronized states. Relation to hypernetworks of chaotic units is also discussed.
    Language: English
    Type: http://purl.org/escidoc/metadata/ves/publication-types/article
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  • Publication Date: 2016-10-11
    Description: Erosion can be observed in many arable soil landscapes such as those of the hummocky ground moraine. The topsoil removal by water erosion in combination with tillage operations (e.g., ploughing) is leading to truncated soil profiles along slopes with reduced solum thickness and modified properties of soil horizons. The objectives were to identify and quantify effects of erosion-induced soil modifications on the water balance and the leaching of dissolved organic and inorganic carbon (DOC, DIC), considering complex soil-crop interactions. The idea was to compare lysimeter-based water and solute balances of eroded Luvisols that differed in solum depth. The six high precision weighing lysimeters (1.0 m2 surface, 1.5 m high; UMS Science-Lysimeter) had a resolution of 10 g (=0.01 mm). The cylindrical steel rings of the lysimeters were filled with undisturbed soil monoliths from two fields. Lysimeter soils were cultivated with maize, winter rye, Sudangrass, triticale, alfalfa, and Persian clover during the observation period April 2011 to March 2014. Cumulative drainage of the six lysimeter soils ranged from 57 for the least to 104 mm y−1 for the most eroded Luvisols; the differences of about 83% indicated that the erosional profile modifications in combination with differences in crop development affected the water balance components. Soil-crop interactions depending on properties of differently-truncated soil profiles caused varying amounts of precipitation and evapotranspiration for the 3-years. Since lysimeter effluent concentrations of DOC (5 ± 0.5 mg L−1) and DIC (62 ± 5 mg L−1) were relatively constant in time, the DOC and DIC leaching was mainly controlled by the water fluxes. Thus, the leaching rates ranged from 0.3 (Luvisol) to 0.5 g m−2 yr−1 (eroded Luvisol) for DOC and 3.3 (Luvisol) to 7.1 g m−2 yr−1 (eroded Luvisol) for DIC. Because of the complex soil crop interactions, a clear relation between erosion-induced soil profile modification and the water balance and DOC and DIC leaching could not be identified. Nevertheless, when transferring lysimeter results to the arable soil landscape the erosion-induced modifications even within the same pedogenetic soil type should be considered.
    Language: English
    Type: http://purl.org/escidoc/metadata/ves/publication-types/article
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  • Publication Date: 2016-10-15
    Description: Exploration Mission 1 (EM-1) will be the first mission to send an uncrewed Orion vehicle to cislunar space in 2018, targeted to a Distant Retrograde Orbit (DRO). Analysis of EM-1 DRO mission opportunities in 2018 help characterize mission parameters that are of interest to other subsystems (e.g., power, thermal, communications, flight operations, etc). Subsystems request mission design trades which include: landing lighting, addition of an Orion main engine checkout burn, and use of auxiliary thruster only cases. This paper examines the evolving trade studies that incorporate subsystem feedback and demonstrate the feasibility of these constrained mission trajectory designs and contingencies.
    Keywords: Astrodynamics
    Type: JSC-CN-37610 , AAS/AIAA Space Flight Mechanics Meeting; 5-9 Feb. 2017; San Antonio, TX; United States
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  • Publication Date: 2016-10-15
    Description: While Ocular Coherence Tomography (OCT) is not a first-line modality to evaluate anterior eye structures terrestrially, it is a resource already available on the International Space Station (ISS) that can be used in medical contingencies that involve the anterior eye. With remote guidance and subject matter expert (SME) support from the ground, a minimally trained crewmember can now use OCT to evaluate anterior eye pathologies on orbit. OCT utilizes low-coherence interferometry to produce detailed cross-sectional and 3D images of the eye in real time. Terrestrially, it has been used to evaluate macular pathologies and glaucoma. Since 2013, OCT has been used onboard the ISS as one part of a suite of hardware to evaluate the Visual Impairment/Intracranial Pressure risk faced by astronauts, specifically assessing changes in the retina and choroid during space flight. The Anterior Segment Module (ASM), an add-on lens, was also flown for research studies, providing an opportunity to evaluate the anterior eye in real time if clinically indicated. Anterior eye pathologies that could be evaluated using OCT were identified. These included corneal abrasions and ulcers, scleritis, and acute angle closure glaucoma. A remote guider script was written to provide ground specialists with step-by-step instructions to guide ISS crewmembers, who do not get trained on the ASM, to evaluate the anterior eye. The instructions were tested on novice subjects and/or operators, whose feedback was incorporated iteratively. The final remote guider script was reviewed by SME optometrists and NASA flight surgeons. The novel application of OCT technology to space flight allows for the acquisition of objective data to diagnose anterior eye pathologies when other modalities are not available. This demonstrates the versatility of OCT and highlights the advantages of using existing hardware and remote guidance skills to expand clinical capabilities in space flight.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37608 , Aerospace Medical Association Scientific Meeting (AsMA); 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-10-24
    Description: During a survey of Phytophthora diversity in natural ecosystems in Taiwan six new species were detected. Multigene phylogeny based on the nuclear ITS, ß-tubulin and HSP90 and the mitochondrial cox1 and NADH1 gene sequences demonstrated that they belong to ITS Clade 7a with P. europaea, P. uniformis, P. rubi and P. cambivora being their closest relatives. All six new species differed from each other and from related species by a unique combination of morphological characters, the breeding system, cardinal temperatures and growth rates. Four homothallic species, P. attenuata, P. flexuosa, P. formosa and P. intricata, were isolated from rhizosphere soil of healthy forests of Fagus hayatae, Quercus glandulifera, Q. tarokoensis, Castanopsis carlesii, Chamaecyparis formosensis and Araucaria cunninghamii. Two heterothallic species, P. xheterohybrida and P. xincrassata, were exclusively detected in three forest streams. All P. xincrassata isolates belonged to the A2 mating type while isolates of P. xheterohybrida represented both mating types with oospore abortion rates according to Mendelian ratios (4–33 %). Multiple heterozygous positions in their ITS, ß-tubulin and HSP90 gene sequences indicate that P. xheterohybrida, P. xincrassata and P. cambivora are interspecific hybrids. Consequently, P. cambivora is redescribed as P. xcambivora without nomenclatural act. Pathogenicity trials on seedlings of Castanea sativa, Fagus sylvatica and Q. suber indicate that all six new species might pose a potential threat to European forests.
    Keywords: biosecurity ; breeding systems ; evolution ; flow cytometry ; phylogeny ; Phytophthora cambivora ; radiation
    Repository Name: National Museum of Natural History, Netherlands
    Type: Article / Letter to the editor
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  • Publication Date: 2016-10-25
    Description: To provide multi-centennial, annually-resolved records of climate for arid and semi-arid areas of Australia it is necessary to investigate the potential climate signals in tree species in this large region. Using a stable isotope and x-ray fluorescence approach to dendrochronology in Acacia cambagei, this study demonstrates short (10 years) proxies of temperature and precipitation are possible. Because rings in A. cambagei are difficult to see, precluding traditional dendrochronology, we used elemental abundances of Ca and Sr as an annual chronometer back to 1962. Radiocarbon analysis confirmed that our dating of wood from two trees. We compared δ13C and δ18O from the α-cellulose of the dated wood over the most recent 10 years (n = 10) to local climate records demonstrating significant relationships between δ18O and precipitation (r = −0.85, p < 0.002); mean monthly maximum temperature (r = 0.69, p < 0.03); and drought indexes (CRU scPDSI 0.5°, r = −0.89, p < 0.001) for February and March. Acacia cambagei may be useful in developing regional networks of climate proxies for drought. Using modern trees, in combination with architectural timbers, it may be possible to construct a multi-century, annually-resolved proxy-record of rainfall and temperature for semi-arid north-eastern Australia.
    Type: http://purl.org/escidoc/metadata/ves/publication-types/article
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  • Publication Date: 2016-10-31
    Description: Numerical ice sheet models constrained by theory and refined by comparisons with observational data are a central component of work to address the interactions between the cryosphere and changing climate, at a wide range of scales. Although there continue to be significant advances in modelling, major challenges still exist, in particular in terms of downscaling global climate model output to estimate regional and local climate patterns that are critical controls for the dynamics of glaciers and ice sheets. Ice sheet models are tested and refined by comparing model predictions of past ice geometries with field-based reconstructions from geological, geomorphological, and ice core data. However, on the East Antarctic Ice sheet, there is a critical gap in the empirical data required to reconstruct changes in ice sheet geometry in the Dronning Maud Land (DML) region. In addition, there is poor control on the regional climate history of the ice sheet margin, because ice core locations, where detailed reconstructions of climate history exist, are located on high inland domes. This leaves numerical models of regional glaciation history in this near-coastal area largely unconstrained. MAGIC-DML is an ongoing Swedish-US-Norwegian-German-UK collaboration with a focus on improving ice sheet models by combining advances in modeling with filling critical data gaps that exist in our knowledge of the timing and pattern of ice surface changes on the western Dronning Maud Land margin. A combination of geomorphological mapping using remote sensing data, field investigations, cosmogenic nuclide surface exposure dating, and numerical ice-sheet modelling are being used in an iterative manner to produce a comprehensive reconstruction of the glacial history of western Dronning Maud Land. We present an overview of the project, as well as results of the initial mapping and modelling that has been used to identify high potential sites for field sampling in 2016/17 and 2017/18.
    Repository Name: EPIC Alfred Wegener Institut
    Type: Conference , NonPeerReviewed
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  • Publication Date: 2016-11-02
    Description: Congestion is commonly reported during spaceflight, and most crewmembers have reported using medications for congestion during International Space Station (ISS) missions. Although congestion has been attributed to fluid shifts during spaceflight, fluid status reaches equilibrium during the first week after launch while congestion continues to be reported throughout long duration missions. Congestion complaints have anecdotally been reported in relation to ISS CO2 levels; this evaluation was undertaken to determine whether or not an association exists. METHODS: Reported headaches, congestion symptoms, and CO2 levels were obtained for ISS expeditions 2-31, and time-weighted means and single-point maxima were determined for 24-hour (24hr) and 7-day (7d) periods prior to each weekly private medical conference. Multiple imputation addressed missing data, and logistic regression modeled the relationship between probability of reported event of congestion or headache and CO2 levels, adjusted for possible confounding covariates. The first seven days of spaceflight were not included to control for fluid shifts. Data were evaluated to determine the concentration of CO2 required to maintain the risk of congestion below 1% to allow for direct comparison with a previously published evaluation of CO2 concentrations and headache. RESULTS: This study confirmed a previously identified significant association between CO2 and headache and also found a significant association between CO2 and congestion. For each 1-mm Hg increase in CO2, the odds of a crew member reporting congestion doubled. The average 7-day CO2 would need to be maintained below 1.5 mmHg to keep the risk of congestion below 1%. The predicted probability curves of ISS headache and congestion curves appear parallel when plotted against ppCO2 levels with congestion occurring at approximately 1mmHg lower than a headache would be reported. DISCUSSION: While the cause of congestion is multifactorial, this study showed congestion is associated with CO2 levels on ISS. Data from additional expeditions could be incorporated to further assess this finding. CO2 levels are also associated with reports of headaches on ISS. While it may be expected for astronauts with congestion to also complain of headaches, these two symptoms are commonly mutually exclusive. Furthermore, it is unknown if a temporal CO2 relationship exists between congestion and headache on ISS. CO2 levels were time-weighted for 24hr and 7d, and thus the time course of congestion leading to headache was not assessed; however, congestion could be an early CO2-related symptom when compared to headache. Future studies evaluating the association of CO2-related congestion leading to headache would be difficult due to the relatively stable daily CO2 levels on ISS currently, but a systematic study could be implemented on-orbit if desired.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37736 , Aerospace Medical Association Meeting; 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-11-01
    Description: The surface of Mars once had abundant water flowing on its surface, but now there is a general perception that this surface is completely dry. Several lines of research have shown that there are sources of potentially large quantities of water at many locations on the surface, including regions considered as candidates for future human missions. Traditionally, system designs for these human missions are constrained to tightly recycle water and oxygen, and current resource utilization strategies involve ascent vehicle oxidizer production only. But the assumption of relatively abundant extant water may change this. Several scenarios were constructed to evaluate water requirements for human Mars expeditions to assess the impact to system design if locally produced water is available. Specifically, we have assessed water resources needed for 1) ascent vehicle oxidizer and fuel production, 2) open-loop water and oxygen life support requirements along with more robust usage scenarios, and 3) crew radiation protection augmentation. In this assessment, production techniques and the associated chemistry to transform Martian water and atmosphere into these useful commodities are identified, but production mass and power requirements are left to future analyses. The figure below illustrates the type of water need assessment performed and that will be discussed. There have been several sources of feedstock material discussed in recent literature that could be used to produce these quantities of water. This paper will focus on Mars surface features that resemble glacier-like forms on Earth. Several lines of evidence indicate that some of these features are in fact buried ice, likely remnants from an earlier ice age on Mars. This paper examines techniques and hardware systems used in the polar regions of Earth to access this buried ice and withdraw water from it. These techniques and systems will be described to illustrate options available. A technique known as a Rodriguez Well is assessed as a likely method for extracting water from these bodies of ice. The figure below is a sample of results from this assessment that will be discussed.
    Keywords: Lunar and Planetary Science and Exploration
    Type: JSC-CN-36635-1 , IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-11-01
    Description: In the last few years, radio technologies for unmanned aircraft vehicle (UAV) have advanced very rapidly. The increasing need to fly unmanned aircraft systems (UAS) in the national airspace system (NAS) to perform missions of vital importance to national security, defense, and science has pushed ahead the design and implementation of new radio platforms. However, a lot still has to be done to improve those radios in terms of performance and capabilities. In addition, an important aspect to account for is hardware cost and the feasibility to implement these radios using commercial off-the-shelf (COTS) components. UAV radios come with numerous technical challenges and their development involves contributions at different levels of the design. Cognitive algorithms need to be developed in order to perform agile communications using appropriate frequency allocation while maintaining safe and efficient operations in the NAS and, digital reconfigurable architectures have to be designed in order to ensure a prompt response to environmental changes. Command and control (C2) communications have to be preserved during "standard" operations while crew operations have to be minimized. It is clear that UAV radios have to be software-defined systems, where size, weight and power consumption (SWaP) are critical parameters. This paper provides preliminary results of the efforts performed to design a fully digital radio architecture as part of a NASA Phase I STTR. In this paper, we will explain the basic idea and technical principles behind our dynamic/adaptive frequency hopping radio for UAVs. We will present our Simulink model of the dynamic FH radio transmitter design for UAV communications and show simulation results and FPGA system analysis.
    Keywords: Air Transportation and Safety ; Space Sciences (General) ; Communications and Radar
    Type: GRC-E-DAA-TN30791 , Integrated Communication Navigation Systems (ICNS 2016); 19-21 Apr. 2017; Herndon, VA; United States
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  • Publication Date: 2016-11-04
    Description: Enhanced screening for the Visual Impairment/Intracranial Pressure (VIIP) syndrome has been implemented to better characterize the ocular and vision changes observed in some long-duration crewmembers. This includes implementation of in-flight ultrasound in 2010 and optical coherence tomography (OCT) in 2013. Potential risk factors for VIIP include cardiovascular health, diet, anatomical and genetic factors, and environmental conditions. Carbon dioxide (CO2), a potent vasodilator, is chronically elevated on the International Space Station (ISS) relative to ambient levels on Earth, and is a plausible risk factor for VIIP. In an effort to understand the possible associations between CO2 and VIIP, this study explores the relationship of ambient CO2 levels on ISS compared to inflight ultrasound and OCT measures of the eye obtained from ISS crewmembers. CO2 measurements were aggregated from Operational Data Reduction Complex and Node 3 major constituent analyzers (MCAs) on ISS or from sensors located in the European Columbus module, as available. CO2 levels in the periods between each ultrasound and OCT session are summarized using timeseries metrics, including time-weighted means and variances. Partial least squares regression analyses are used to quantify the complex relationship between specific ultrasound and OCT measures and the CO2 metrics simulataneously. These analyses will enhance our understanding of the possible associations between CO2 levels and structural changes to the eye which will in turn inform future analysis of inflight VIIP data.
    Keywords: Life Sciences (General) ; Aerospace Medicine
    Type: JSC-CN-37739 , Human Research Program Investigators' Workshop (2017 HRP IWS); 23-27 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-03
    Description: NASA, in planning for long-duration missions, has an imperative to provide a food system with the necessary nutrition, acceptability, and safety to ensure sustainment of crew health and performance. The Orion Multi-Purpose Crew Vehicle (MPCV) and future exploration missions are mass constrained; therefore the team is challenged to reduce the mass of the food system by 10% while maintaining product safety, nutrition, and acceptability. Commercially available products do not meet the nutritional requirements for a full meal replacement in the spaceflight food system, and it is currently unknown if daily meal replacements will impact crew food intake and psychosocial health over time. The purpose of this study was to develop a variety of nutritionally balanced breakfast replacement bars that meet spaceflight nutritional, microbiological, sensorial, and shelf-life requirements, while enabling a 10% savings in food mass. To date, six nutrient-dense meal replacement bars (approximately 700 calories per bar) have been developed, using traditional methods of compression as well as novel ultrasonic compression technologies developed by Creative Resonance Inc. (Phoenix, AZ). The four highest rated bars were evaluated in the Human Exploration Research Analog (HERA) to assess the frequency with which actual meal replacement options may be implemented. Specifically, overall impact of bars on mood, satiety, digestive discomfort, and satisfaction with food. These factors are currently being analyzed to inform successful implementation strategies where crew maintain adequate food intake. In addition, these bars are currently undergoing shelf-life testing to determine long-term sensory acceptability, nutritional stability, qualitative stability of analytical measurements (i.e. water activity and texture), and microbiological compliance over two years of storage at room temperature and potential temperature abuse conditions to predict long-term acceptability. It is expected that this work will enable a successful meal replacement strategy to be implemented that will maintain crew food consumption and health, while informing exploration missions with appropriate mass savings expectations.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-37796 , 2017 Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-03
    Description: As spaceflight durations have increased over the last four decades, the effects of microgravity on the human body have become far better understood, as have the exercise countermeasures. Through use of a combination of aerobic and resistive exercise devices, today's astronauts and cosmonauts are able to partially counter the losses in muscle strength, aerobic fitness, and bone strength that otherwise might occur during their missions on the International Space Station (ISS). Since 2000, the ISS has employed a variety of exercise equipment used as countermeasures to these risks. Providing reliable and available exercise systems has presented significant challenges due to the unique environment. In solving these, lessons have been learned that can inform development of future systems.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37633 , JETS-JE11-15-SAIP-DOC-0084 , 2017 IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-11-03
    Description: This panel presents recent updates to and a comprehensive overview of the operational medical support provided to ISS crewmembers in Star City, Russia and Kazakhstan as part of UTMB/KBRwyle's Human Health & Performance contract. With the current Soyuz training flow, physician support is required for nominal training evolutions involving pressure changes or other potential physical risks detailed in this presentation. In addition, full-time physician presence in Star City helps to address the disparity in access to health care in these relatively remote practice areas, while also developing and maintaining relationships with host nation resources. A unique part of standard training in Russia also involves survival training in both winter and water environments; logistic details and medical impacts of each of these training scenarios will be discussed. Following support of a successful training flow, UTMB/KBRwyle's Star City Medical Support Group (SCMSG) is also responsible for configuring medical packs in support of Soyuz launches and landings; we will present the rationale for current pack contents within the context of specific operational needs. With respect to contingency events, the group will describe their preparedness to respond appropriately by activating both local and global resources as necessary, detailing a specialized subset of the group who continually work and update these assets, given changes in international infrastructure and other impacts.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37623 , AsMA Annual Scientific Meeting; 29 Apr. - 4 May 2017 ; Denvor, CO; United States
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  • Publication Date: 2016-11-05
    Description: Cross-system studies on the response of different ecosystems to global change will support our understanding of ecological changes. Synoptic views on the planet's two main realms, the marine and terrestrial, however, are rare, owing to the development of rather disparate research communities.We combined questionnaires and a literature review to investigate howthe importance of anthropogenic drivers of biodiversity change differs amongmarine and terrestrial systems and whether differences perceived by marine vs. terrestrial researchers are reflected by the scientific literature. This included asking marine and terrestrial researchers to rate the relevance of different drivers of global change for either marine or terrestrial biodiversity. Land use and the associated loss of natural habitatswere rated as most important in the terrestrial realm,while the exploitation of the sea by fishing was rated as most important in the marine realm. The relevance of chemicals, climate change and the increasing atmospheric concentration of CO2 were rated differently for marine and terrestrial biodiversity respectively. Yet, our literature review provided less evidence for such differences leading to the conclusion that while the history of the use of land and sea differs, impacts of global change are likely to become increasingly similar.
    Repository Name: EPIC Alfred Wegener Institut
    Language: en
    Type: Article , NonPeerReviewed
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  • Publication Date: 2016-11-05
    Description: For the past four years, the Air Quality Monitor (AQM) has been the operational instrument for measuring trace volatile organic compounds on the International Space Station (ISS). The key components of the AQM are the inlet preconcentrator, the gas chromatograph (GC), and the differential mobility spectrometer. Most importantly, the AQM operates at atmospheric pressure and uses air as the GC carrier gas, which translates into a small reliable instrument. Onboard ISS there are two AQMs, with different GC columns that detect and quantify 22 compounds. The AQM data contributes valuable information to the assessment of air quality aboard ISS for each crew increment. The U.S. Navy is looking to update its submarine air monitoring suite of instruments, and the success of the AQM on ISS has led to a jointly planned submarine sea trial of a NASA AQM. In addition to the AQM, the Navy is also interested in the Multi-Gas Monitor (MGM), which was successfully flown on ISS as a technology demonstration to measure major constituent gases (oxygen, carbon dioxide, water vapor, and ammonia). A separate paper will present the MGM sea trial results. A prototype AQM, which is virtually identical to the operational AQM, has been readied for the sea trial. Only one AQM will be deployed during the sea trial, but it is sufficient to detect the compounds of interest to the Navy for the purposes of this trial. A significant benefit of the AQM is that runs can be scripted for pre-determined intervals and no crew intervention is required. The data from the sea trial will be compared to archival samples collected prior to and during the trial period. This paper will give a brief overview of the AQM technology and protocols for the submarine trial. After a quick review of the AQM preparation, the main focus of the paper will be on the results of the submarine trial. Of particular interest will be the comparison of the contaminants found in the ISS and submarine atmospheres, as both represent closed environments. In U.K. submarine trials in the early 2000s, the submarine and ISS atmospheres were found to be remarkably similar.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-37932 , International Conference on Environmental Systems (ICES); 16-20 Jul. 2017; Charleston, SC; United States
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  • Publication Date: 2016-11-05
    Description: INTRODUCTION: Long-duration missions beyond low Earth orbit introduce new constraints to the space medical system. Beyond the traditional limitations in mass, power, and volume, consideration must be given to other factors such as the inability to evacuate to Earth, communication delays, and limitations in clinical skillsets. As NASA develops the medical system for an exploration mission, it must have an ability to evaluate the trade space of what resources will be most important. The Medical Optimization Network for Space Telemedicine Resources (MONSTR) was developed over the past year for this reason, and is now a system for managing data pertaining to medical resources and their relative importance when addressing medical conditions. METHODS: The MONSTR web application with a Microsoft SQL database backend was developed and made accessible to Tableau v9.3 for analysis and visualization. The database was initially populated with a list of medical conditions of concern for an exploration mission taken from the Integrated Medical Model (IMM), a probabilistic model designed to quantify in-flight medical risk. A team of physicians working within the Exploration Medical Capability Element of NASA's Human Research Program compiled a list diagnostic and treatment medical resources required to address best- and worst-case scenarios of each medical condition using a terrestrial standard of care and entered this data into the system. This list included both tangible resources (e.g. medical equipment, medications) and intangible resources (e.g. clinical skills required to perform a procedure). The physician team then assigned criticality values to each instance of a resource, representing the importance of that resource to diagnosing or treating its associated condition(s). Medical condition probabilities of occurrence during a Mars mission were pulled from the IMM and imported into the MONSTR database for use within a resource criticality-weighting algorithm. DISCUSSION: The MONSTR tool is a novel approach to assess the relative value of individual resources needed for the diagnosis and treatment of medical conditions. Future work will add resources for prevention and long term care of these conditions. Once data collection is complete, MONSTR will provide the operational and research communities at NASA with information to support informed decisions regarding areas of research investment, future crew training, and medical supplies manifested as part of any exploration medical system.
    Keywords: Aerospace Medicine ; Computer Programming and Software
    Type: JSC-CN-37819 , NASA Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2016; Galveston, TX; United States
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  • Publication Date: 2016-11-05
    Description: Future exploration missions will be the first time humanity travels beyond Low Earth Orbit (LEO) since the Apollo program, taking us to cis-lunar space, interplanetary space, and Mars. These long-duration missions will cover vast distances, severely constraining opportunities for emergency evacuation to Earth and cargo resupply opportunities. Communication delays and blackouts between the crew and Mission Control will eliminate reliable, real-time telemedicine consultations. As a result, compared to current LEO operations onboard the International Space Station, exploration mission medical care requires an integrated medical system that provides additional in-situ capabilities and a significant increase in crew autonomy. The Medical System Concept of Operations for Mars Exploration Missions illustrates how a future NASA Mars program could ensure appropriate medical care for the crew of this highly autonomous mission. This Concept of Operations document, when complete, will document all mission phases through a series of mission use case scenarios that illustrate required medical capabilities, enabling the NASA Human Research Program (HRP) Exploration Medical Capability (ExMC) Element to plan, design, and prototype an integrated medical system to support human exploration to Mars.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37894 , Human Research Program Investigators' Workshop (HRP IWS 2017 ); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-05
    Description: Back by popular demand, the JSC Biostatistics Laboratory and LSAH statisticians are offering an opportunity to discuss your statistical challenges and needs. Take the opportunity to meet the individuals offering expert statistical support to the JSC community. Join us for an informal conversation about any questions you may have encountered with issues of experimental design, analysis, or data visualization. Get answers to common questions about sample size, repeated measures, statistical assumptions, missing data, multiple testing, time-to-event data, and when to trust the results of your analyses.
    Keywords: Statistics and Probability
    Type: JSC-CN-37884 , 2017 Human Research Program Investigators' Workshop (HRP IWS) ; 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-05
    Description: NASA has demonstrated an interest in improving astronaut health and performance through the installment of a new lighting countermeasure on the International Space Station. The Solid State Lighting Assembly (SSLA) system is designed to positively influence astronaut health by providing a daily change to light spectrum to improve circadian entrainment. Unfortunately, existing NASA standards and requirements define ambient light level requirements for crew sleep and other tasks, yet the number of light-emitting diode (LED) indicators and displays within a habitable volume is currently uncontrolled. Because each of these light sources has its own unique spectral properties, the additive lighting environment ends up becoming something different from what was planned or researched. Restricting the use of displays and indicators is not a solution because these systems provide beneficial feedback to the crew. The research team for this grant used computer-based computational modeling and real-world lighting mockups to document the impact that light sources other than the ambient lighting system contribute to the ambient spectral lighting environment. In particular, the team was focused on understanding the impacts of long-term tasks located in front of avionics or computer displays. The team also wanted to understand options for mitigating the changes to the ambient light spectrum in the interest of maintaining the performance of a lighting countermeasure. The project utilized a variety of physical and computer-based simulations to determine direct relationships between system implementation and light spectrum. Using real-world data, computer models were built in the commercially available optics analysis software Zemax Optics Studio(c). The team also built a mockup test facility that had the same volume and configuration as one of the Zemax models. The team collected over 1200 spectral irradiance measurements, each representing a different configuration of the mockup. Analysis of the data showed a measurable impact on ambient light spectrum. This data showed that obvious design techniques exist that can be used to bind the ambient light spectrum closer to the planned spectral operating environment for the observer's eye point. The following observations should be considered when designing an operational environment that is dominated by computer displays. When more light is directed into the field of view of the observer, the greater the impact it will make on various human factors issues that depend on spectral shape and intensity. Because viewing angle has a large part to play in the amount of light flux on the crewmember's retina, beam shape, combined with light source location is an important factor for determining percent probable incident flux on the observer from any combination of light sources. Computer graphics design and display lumen output are major factors influencing the amount of spectrally intense light projected into the environment and in the viewer's direction. Use of adjustable white point display software was useful only if the predominant background color was white and if it matched the ambient light system's color. Display graphics that used a predominantly black background had the least influence on unplanned spectral energy projected into the environment. Percent reflectance makes a difference in total energy reflected back into an environment, and within certain architectural geometries, reflectance can be used to control the amount of a light spectrum that is allowed to perpetuate in the environment. Data showed that room volume and distance from significant light sources influence the total spectrum in a room. Smaller environments had a homogenizing effect on total light spectrum, whereas light from multiple sources in larger environments was less mixed. The findings indicated above should be considered when making recommendations for practice or standards for architectural systems. The ambient lighting system, surface reflectance, and display and indicator implementation all factor into the users' spectral environment. A variety of low-cost solutions exist to mitigate the impact of light from non-architectural lighting systems, and much potential for system automation and integration of display systems with the ambient environment. This team believes that proper planning can be used to avoid integration problems and also believes that human-in-the-loop evaluations, real-world test and measurement, and computer modeling can be used to determine how changes to a process, display graphics, and architecture will help maintain the planned spectral operating lighting environment.
    Keywords: Spacecraft Design, Testing and Performance ; Man/System Technology and Life Support
    Type: JSC-CN-37891 , Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Glaveston, TX; United States
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  • Publication Date: 2016-11-08
    Description: Human missions to Mars may require radical changes in the approach to extra-vehicular (EVA) suit design. A major challenge is the balance of building a suit robust enough to complete multiple EVAs under intense ultraviolet (UV) light exposure without losing mechanical strength or compromising the suit's mobility. To study how the materials degrade on Mars in-situ, the Jet Propulsion Laboratory (JPL) invited the Advanced Space Suit team at NASA's Johnson Space Center (JSC) to place space suit materials on the Scanning Habitable Environments with Raman & Luminescence for Organics and Chemicals (SHERLOC) instrument's calibration target of the Mars 2020 rover. In order to select materials for the rover and understand the effects from Mars equivalent UV exposure, JSC conducted ground testing on both current and new space suit materials when exposed to 2500 hours of Mars mission equivalent UV. To complete this testing, JSC partnered with NASA's Marshall Space Flight Center to utilize their UV vacuum chambers. Materials tested were Orthofabric, polycarbonate, Teflon, Dacron, Vectran, spectra, bladder, nGimat coated Teflon, and nGimat coated Orthofabric. All samples were measured for mass, tensile strength, and chemical composition before and after radiation. Mass loss was insignificant (less than 0.5%) among the materials. Most materials loss tensile strength after radiation and became more brittle with a loss of elongation. Changes in chemical composition were seen in all radiated materials through Spectral Analysis. Results from this testing helped select the materials that will fly on the Mars 2020 rover. In addition, JSC can use this data to create a correlation to the chemical changes after radiation-which is what the rover will send back while on Mars-to the mechanical changes, such as tensile strength.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-37805 , International Conference on Environmental Systems (ICES 2017); 16-20 Jul. 2017; Charleston, SC; United States
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  • facet.materialart.
    Springer
    , ed. by Brasseur, G. P., Jacob, D. and Schuck-Zöller, S. Springer, Berlin, Germany, 348 pp. ISBN 978-3-662-50397-3
    Publication Date: 2016-11-11
    Description: Erstmals trägt dieses nationale Assessment den Forschungsstand zum Klimawandel umfassend für alle Themenbereiche und gesellschaftlichen Sektoren zusammen. Womit müssen wir in Deutschland rechnen, welche Auswirkungen werden die Klimaveränderungen auf Wirtschaft und Gesellschaft haben, und wie können wir uns wappnen? 126 Autoren aus ganz Deutschland äußern sich zu Themen wie bereits beobachtete und zukünftige Veränderungen, Wetterkatastrophen und deren Folgen, den Projektionen für die Zukunft, den Risiken sowie möglichen Anpassungsstrategien. Die Autoren stellen in verständlicher Sprache den aktuellen Forschungsstand dar und veranschaulichen die wichtigsten Gedanken in Grafiken und Tabellen. Alle Texte wurden mehrfach wissenschaftlich begutachtet. Klimawandel in Deutschland ist die erste Gesamtschau zu dem Themenkomplex, benennt offene Fragestellungen und liefert eine Grundlage für Entscheidungen im Zusammenhang mit dem Klimawandel. Deutschland reiht sich damit ein in die Liste von Ländern wie die Vereinigten Staaten, Österreich und Großbritannien, in denen derartige Berichte bereits vorliegen. Die Herausgeber: Prof. Dr. Guy Brasseur und Prof. Dr. Daniela Jacob, ehemaliger Direktor und gegenwärtige Direktorin des Climate Center Germany/Helmholtz-Zentrum Geesthacht, und Susanne Schuck-Zöller, die auch die Projektleitung übernommen hat, werden bei diesem Buch unterstützt von einem Editorial Board, dem elf herausragende Wissenschaftler aus den wichtigsten Klimaforschungseinrichtungen in Deutschland angehören
    Repository Name: Oceanrep Geomar
    Type: Book , NonPeerReviewed
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  • Publication Date: 2016-11-11
    Description: This study was the first in a series of planned tests to use physics-based subsystem simulations to investigate the interactions between a spacecraft's crew and a ground-based mission control center for vehicle subsystem operations across long communication delays. The simulation models the life support system of a deep space habitat. It contains models of an environmental control and life support system, an electrical power system, an active thermal control systems, and crew metabolic functions. The simulation has three interfaces: 1) a real-time crew interface that can be use to monitor and control the subsystems; 2) a mission control center interface with data transport delays up to 15 minute each way; and 3) a real-time simulation test conductor interface used to insert subsystem malfunctions and observe the interactions between the crew, ground, and simulated vehicle. The study was conducted at the 21st NASA Extreme Environment Mission Operations (NEEMO) mission. The NEEMO crew and ground support team performed a number of relevant deep space mission scenarios that included both nominal activities and activities with system malfunctions. While this initial test sequence was focused on test infrastructure and procedures development, the data collected in the study already indicate that long communication delays have notable impacts on the operation of deep space systems. For future human missions beyond cis-lunar, NASA will need to design systems and support tools to meet these challenges. These will be used to train the crew to handle critical malfunctions on their own, to predict malfunctions and assist with vehicle operations. Subsequent more detailed and involved studies will be conducted to continue advancing NASA's understanding of space systems operations across long communications delays.
    Keywords: Ground Support Systems and Facilities (Space) ; Space Communications, Spacecraft Communications, Command and Tracking
    Type: JSC-CN-37700 , 2017 IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-11-15
    Description: In this study, we report an extensive paleomagnetic study (76 sites) carried out in the Alborz Mts. (northern Iran), with the aim of reconstructing the rotation history and the origin of curvature of this orogenic chain. The analyzed deposits are the sedimentary successions of the Upper Red Formation (Miocene), Lower Red Formation (Oligocene) and Eocene clastic units. Paleomagnetic results indicate that the Alborz Mts. can be considered a secondary arc that originated as a linearmountain belt that progressively acquired its present day curvature through opposite vertical axis rotations along its strike. The curvature of the arc was entirely acquired after the middlelate Miocene,which is the age of the youngest investigated sediments (Upper Red Formation). Overall, our paleomagnetic data indicate that the Alborz Mts. can be considered an orocline. Our results define, for the first time, the rotational history of the entire Alborz curved mountain belt, and enable us to reconstruct the paleogeographic and tectonic evolution of northern Iran in the framework of Arabia-Eurasia continental deformation. The kinematics inferred by the pattern of paleomagnetic rotations is at odds with the present day kinematics of northern Iran, characterized by the westward extrusion of the South Caspian block, and by a left lateral shear between Central Iran and the central and western sectors of the Alborz Mts. By integrating paleomagnetic datawith stratigraphic, thermochronological, structural and GPS information,we propose that the initiation of South Caspian subduction and the activation of westward extrusion of South Caspian block occurred diachronously and that the initiation of the present-day kinematics of northern Iran was quite recent (Lower Pleistocene, b2 Ma).
    Keywords: Paleomagnetism Alborz Iran orocline ; 04. Solid Earth::04.05. Geomagnetism::04.05.06. Paleomagnetism
    Repository Name: Istituto Nazionale di Geofisica e Vulcanologia (INGV)
    Language: English
    Type: article
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  • Publication Date: 2016-11-18
    Description: This paper presents the results of a NASA initiated Agency-wide assessment to better characterize the risks and potential mitigation approaches associated with landing human class Entry, Descent, and Landing (EDL) systems on Mars. Due to the criticality and long-lead nature of advancing EDL techniques, it is necessary to determine an appropriate strategy to improve the capability to land large payloads. A key focus of this study was to understand the key EDL risks and with a focus on determining what "must" be tested at Mars. This process identified the various risks and potential risk mitigation strategies along with the key near term technology development efforts required and in what environment those technology demonstrations were best suited. The study identified key risks along with advantages to each entry technology. In addition, it was identified that provided the EDL concept of operations (con ops) minimized large scale transition events, there was no technology requirement for a Mars pre-cursor demonstration. Instead, NASA should take a direct path to a human-scale lander.
    Keywords: Spacecraft Design, Testing and Performance
    Type: JSC-CN-37782 , IEEE Aerospace Conference; 4-11 Mar. 2017; Big Sky, MT; United States
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  • Publication Date: 2016-11-22
    Description: The hypothesis of this work was that exposure to diverse abiotic factors in two sites with different sediment and iron input (Peñón de Pesca: low impact; Island D: high impact, both areas in Potter Cove, King George Island, Antarctica) affects the physiological and oxidative profile of Gigartina skottsbergii and Himantothallus grandifolius. Daily metabolic carbon balance was significantly lower in both macroalgae from Island D compared to Peñón de Pesca. Lipid radical (LRradical dot) content was significantly higher in G. skottsbergii collected from Island D compared to Peñón de Pesca. In contrast, H. grandifolius showed significantly lower values in Island D compared to Peñón de Pesca. The β-carotene (β-C) content was significantly lower in G. skottsbergii from Island D compared to Peñón de Pesca, and the ratio LRradical dot/β-C showed a 6-fold increase in Island D samples compared to Peñón de Pesca. On the other hand, β-C content in H. grandifolius showed no significant differences between both areas. The LRradical dot/β-C content ratio in this alga was significantly lower (26%) in Island D as compared to Peñón de Pesca. Total iron content was significantly higher in both macroalgae from Island D compared to samples from Peñón de Pesca. Results with G. skottsbergii suggested changes in the oxidative cellular balance, probably related to the higher environmental iron in Island D as compared to Peñón de Pesca. The species H. grandifolius seems to be better adapted to the environmental conditions especially through a higher antioxidant capacity to cope with oxidative stress.
    Repository Name: EPIC Alfred Wegener Institut
    Language: en
    Type: Article , NonPeerReviewed , info:eu-repo/semantics/article
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  • Publication Date: 2016-11-24
    Description: Long-term models, such as NASA's LEGEND (LEO (Low-Earth Orbit)-to-GEO (Geosynchrous Earth Orbit) Environment Debris) model, are used to make predictions about how space activities will affect the long-term evolution of the debris environment. Part of this process is to predict how spacecraft and rocket bodies will be launched and left in the environment in the future. This has usually been accomplished by repeating past launch history to simulate future launches. It was partially upon the basis of the results of such models that both national and international orbital debris mitigation guidelines - especially the "25-year rule" for post-mission disposal - were determined. The proliferation of Cubesat launches in recent years, however, has raised concerns that we are seeing a fundamental shift in how humans launch satellites into space that may alter the assumptions upon which our current mitigation guidelines are based. The large number of Cubesats, and their short lifetime and general inability to perform collision avoidance, potentially makes them an important new source of debris. The NASA Orbital Debris Program Office (ODPO) has conducted a series of LEGEND computations to investigate the long-term effects of adding Cubesats to the environment. Several possible future scenarios were simulated to investigate the effects of the size of future Cubesat launches and the efficiency of post-mission disposal on the proliferation of catastrophic collisions over the next 200 years. These results are compared to a baseline "business-as-usual" scenario where launches are assumed to continue as in the past without major Cubesat deployments. Using these results, we make observations about the continued use of the 25-year rule and the importance of the universal application of post-mission disposal. We also discuss how the proliferation of Cubesats may affect satellite traffic at lower altitudes.
    Keywords: Space Transportation and Safety ; Spacecraft Design, Testing and Performance
    Type: JSC-CN-38135 , European Conference on Space Debris; 18-21 Apr. 2017; Darmstadt; Germany
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  • Publication Date: 2016-11-24
    Description: Spectra or similar Ultra-high-molecular-weight polyethylene (UHMWPE) fabric is the likely choice for future structural space suit restraint materials due to its high strength-to-weight ratio, abrasion resistance, and dimensional stability. During long duration space missions, space suits will be subjected to significant amounts of high-energy radiation from several different sources. To insure that pressure garment designs properly account for effects of radiation, it is important to characterize the mechanical changes to structural materials after they have been irradiated. White Sands Test Facility (WSFTF) collaborated with the Crew and Thermal Systems Division at the Johnson Space Center (JSC) to irradiate and test various space suit materials by examining their tensile properties through blunt probe puncture testing and single fiber tensile testing after the materials had been dosed at various levels of simulated GCR and SPE Iron and Proton beams at Brookhaven National Laboratories. The dosages were chosen based on a simulation developed by the Structural Engineering Division at JSC for the expected radiation dosages seen by space suit softgoods seen on a Mars reference mission. Spectra fabric tested in the effort saw equivalent dosages at 2x, 10x, and 20x the predicted dose as well as a simulated 50 year exposure to examine the range of effects on the material and examine whether any degradation due to GCR would be present if the suit softgoods were stored in deep space for a long period of time. This paper presents the results of this work and outlines the impact on space suit pressure garment design for long duration deep space missions.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-37904 , International Conference on Environmental Systems; 16-20 Jul. 2017; Charleston, SC; United States
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  • Publication Date: 2016-11-23
    Description: INTRODUCTION: Among otherwise healthy astronauts undertaking deep space missions, the risks for acute appendicitis (AA) and cholecystitis (AC) are not zero. If these conditions were to occur during spaceflight they may require surgery for definitive care. The proposed study quantifies and compares the risks of developing de novo AA and AC in-flight to the surgical risks of prophylactic laparoscopic appendectomy (LA) and cholecystectomy (LC) using NASA's Integrated Medical Model (IMM). METHODS: The IMM is a Monte Carlo simulation that forecasts medical events during spaceflight missions and estimates the impact of these medical events on crew health. In this study, four Design Reference Missions (DRMs) were created to assess the probability of an astronaut developing in-flight small-bowel obstruction (SBO) following prophylactic 1) LA, 2) LC, 3) LA and LC, or 4) neither surgery (SR# S-20160407-351). Model inputs were drawn from a large, population-based 2011 Swedish study that examined the incidence and risks of post-operative SBO over a 5-year follow-up period. The study group included 1,152 patients who underwent LA, and 16,371 who underwent LC. RESULTS: Preliminary results indicate that prophylactic LA may yield higher mission risks than the control DRM. Complete analyses are pending and will be subsequently available. DISCUSSION: The risk versus benefits of prophylactic surgery in astronauts to decrease the probability of acute surgical events during spaceflight has only been qualitatively examined in prior studies. Within the assumptions and limitations of the IMM, this work provides the first quantitative guidance that has previously been lacking to this important question for future deep space exploration missions.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37914 , Annual Scientific Meeting of the Aerospace Medical Association; 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-11-23
    Description: Astronauts and cosmonauts may experience symptoms of orthostatic intolerance during re-entry, landing, and for several days post-landing following short- and long-duration spaceflight. Presyncopal symptoms have been documented in approximately 20% of short-duration and greater than 60% of long-duration flyers on landing day specifically during 5-10 min of controlled (no countermeasures employed at the time of testing) stand tests or 80 deg head-up tilt tests. Current operational countermeasures to orthostatic intolerance include fluid loading prior to and whole body cooling during re-entry as well as compression garments that are worn during and for up to several days after landing. While both NASA and the Russian space program have utilized compression garments to protect astronauts and cosmonauts traveling on their respective vehicles, a "next-generation" gradient compression garment (GCG) has been developed and tested in collaboration with a commercial partner to support future space flight missions. Unlike previous compression garments used operationally by NASA that provide a single level of compression across only the calves, thighs, and lower abdomen, the GCG provides continuous coverage from the feet to below the pectoral muscles in a gradient fashion (from approximately 55 mm Hg at the feet to approximately 16 mmHg across the abdomen). The efficacy of the GCG has been demonstrated previously after a 14-d bed rest study without other countermeasures and after short-duration Space Shuttle missions. Currently the GCG is being tested during a stand test following long-duration missions (~6 months) to the International Space Station. While results to date have been promising, interactions of the GCG with other space suit components have not been examined. Specifically, it is unknown whether wearing the GCG over NASA's Maximum Absorbency Garment (MAG; absorbent briefs worn for the collection of urine and feces while suited during re-entry and landing) will interfere with the effectiveness of the GCG or conversely whether the GCG will reduce the fluid absorption capabilities of the MAG. Methods: This operational, directed study, will (1) determine whether the effectiveness of the GCG is affected by the MAG with regard to cardiovascular responses to head-up tilt, the standard orthostatic intolerance test employed for astronauts and bed rest subjects; (2) determine whether the effectiveness of the MAG is compromised by the GCG tested by injecting a standard fluid volume (950 ml in 3 separate simulated "urine voids") at a standardized rate (30 ml/sec); and (3) determine whether comfort is affected by wearing the MAG under the GCG using a standardized questionnaire. Results from this study will guide future development and operational use of the GCG and MAG to maximize crew health, safety, and comfort.
    Keywords: Aerospace Medicine
    Type: JSC-CN-38003 , 2017 Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-23
    Description: We will address the Human Factors and Performance Team, "Risk of performance errors due to training deficiencies" by improving the JIT training materials for ultrasound and OCT imaging by providing advanced guidance in a detailed, timely, and user-friendly manner. Specifically, we will (1) develop an audio-visual tutorial using AR that guides non-experts through an abdominal trauma ultrasound protocol; (2) develop an audio-visual tutorial using AR to guide an untrained operator through the acquisition of OCT images; (3) evaluate the quality of abdominal ultrasound and OCT images acquired by untrained operators using AR guidance compared to images acquired using traditional JIT techniques (laptop-based training conducted before image acquisition); and (4) compare the time required to complete imaging studies using AR tutorials with images acquired using current JIT practices to identify areas for time efficiency improvements. Two groups of subjects will be recruited to participate in this study. Operator-subjects, without previous experience in ultrasound or OCT, will be asked to perform both procedures using either the JIT training with AR technology or the traditional JIT training via laptop. Images acquired by inexperienced operator-subjects will be scored by experts in that imaging modality for diagnostic and research quality; experts will be blinded to the form of JIT used to acquire the images. Operator-subjects also will be asked to submit feedback to improve the training modules used during the scans to improve future training modules. Scanned-subjects will be a small group individuals from whom all images will be acquired.
    Keywords: Instrumentation and Photography ; Aerospace Medicine
    Type: JSC-CN-38004 , Human Research Program Investigators' Workshop ; 23-26 Jan. 2017; Galveston, TX ; United States
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  • Publication Date: 2016-11-24
    Description: The purpose of the NASA Institutional Review Board (IRB) is to review research activities involving human subjects to ensure that ethical standards for the care and protection of human subjects have been met and research activities are in compliance with all pertinent federal, state and local regulations as well as NASA policies. NASA IRB's primary role is the protection of human subjects in research studies. Protection of human subjects is the shared responsibility of NASA, the IRB, and the scientific investigators. Science investigators who plan to conduct NASA-funded human research involving NASA investigators, facilities, or funds must submit and coordinate their research studies for review and approval by the NASA IRB prior to initiation. The IRB has the authority to approve, require changes in, or disapprove research involving human subjects. Better knowledge of the NASA IRB policies, procedures and guidelines should help facilitate research protocol applications and approvals. In this presentation, the myths and truths of NASA IRB policies and procedures will be discussed. We will focus on the policies that guide a protocol through the NASA IRB and the procedures that principal investigators must take to obtain required IRB approvals for their research studies. In addition, tips to help ensure a more efficient IRB review will be provided. By understanding the requirements and processes, investigators will be able to more efficiently prepare their protocols and obtain the required NASA IRB approval in a timely manner.
    Keywords: Law, Political Science and Space Policy
    Type: JSC-CN-37908 , Human Research Program Investigator's Workshop; 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-24
    Description: During a successful 2 year technology demonstration of the tunable diode laser spectroscopy (TDLS) based Multi-Gas Monitor (MGM) on the International Space Station (ISS), we began discussing with the US Navy the possibility of conducting a sea trial of an MGM on a submarine. The sea trial would also include a gas chromatography/differential mobility spectrometer based Air Quality Monitor (AQM), which is used operationally on ISS for select volatile organic compounds. AQM results will be the subject of a separate paper. The Navys interest in testing NASA equipment is in a planned update to the environmental monitoring equipment used aboard submarines. NASAs goal is studying submarines as closed environment analogs to spacecraft. MGMs core technology was developed by Vista Photonics Inc using Small Business Innovation Research (SBIR) grants and expanded for various applications using NASA program funding. The MGM measures oxygen, carbon dioxide, ammonia and water vapor in ambient air, displays concentrations with temperature and pressure, and stores 30 second moving averages. The sea trial involves colocating the instrument with the Central Air Monitor (CAM) and connecting it to rack power prior to departure, and letting it run during the entire sea trial of a few months duration. All data stored is inside MGM, with no connection to the vessel data bus. Crew intervention is limited to checking MGM periodically to see that it is working and power cycling if the display is OFF. After the trial is over, the unit with its data will be retrieved. Post sea trial calibration check and data analysis are planned and results will be compared with both CAM data and results from MGMs ISS technology demonstration.
    Keywords: Environment Pollution
    Type: JSC-CN-37909 , International Conference on Environmental Systems (ICES); 16-20 Jul. 2017; Charleston, SC; United States
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  • Publication Date: 2016-11-24
    Description: We have recently completed a long duration head down tilt bed rest (HDBR) study in which we performed structural and functional magnetic resonance brain imaging to identify the relationships between changes in neurocognitive function and neural structural alterations in a spaceflight analog environment. We are also collecting the same measures in crewmembers prior to and following a six month International Space Station mission. We will present data demonstrating that bed rest resulted in functional mobility and balance deterioration with recovery post-HDBR. We observed numerous changes in brain structure, function, and connectivity relative to a control group which were associated with pre to post bed rest changes in sensorimotor function. For example, gray matter volume (GMv) increased in posterior parietal areas and decreased in frontal regions. GMv increases largely overlapped with fluid decreases and vice versa. Larger increases in precentral gyrus (M1)/ postcentral gyrus (S1+2) GMv and fluid decreases were associated with smaller balance decrements. Vestibular activation in the bilateral insular cortex increased with bed rest and subsequently recovered. Larger increases in vestibular activation in multiple brain regions were associated with greater decrements in balance and mobility. We found connectivity increases between left M1 with right S1+2 and the superior parietal lobule, and right vestibular cortex with the cerebellum. Decreases were observed between right Lobule VIII with right S1+2 and the supramarginal gyrus, right posterior parietal cortex (PPC) with occipital regions, and the right superior posterior fissure with right Crus I and II. Connectivity strength between left M1 and right S1+2/superior parietal lobule increased the most in individuals that exhibited the least balance impairments. In sum, we observed HDBR-related changes in measures of brain structure, function, and network connectivity, which correlated with indices of sensorimotor function. Recovery was observed post HDBR but remained incomplete at 12 days post-HDBR. Preliminary findings from our parallel ongoing flight study will be compared and contrasted with bed rest results during this presentation.
    Keywords: Aerospace Medicine ; Behavioral Sciences
    Type: JSC-CN-38007 , 2017 Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-23
    Description: Background: Carotid Intima Media Thickness (CIMT) has been demonstrated to be predictive of future cardiovascular events. Within various populations, radiation exposure, stress, and physical confinement have all been linked to an increased CIMT. Recent research discovered CIMT was significantly increased in ten long duration astronauts from pre-flight to four days post flight. The relationship between spaceflight and CIMT is not understood and trends in CIMT within the larger astronaut population are unknown. Methods: In 2010, CIMT was offered as part of the astronaut annual exam at the JSC Flight Medicine Clinic using a standardized CIMT screening protocol and professional sonographers. Between 2010 and 2016, CIMT measurements were collected on 213 NASA astronauts and payload specialists. The values used in this retrospective chart review are the mean of the CIMT from the right and left. Spaceflight exposure was categorized based on the total number of days spent in space at the time of the ground-based ultrasound (0, 1-29, 30-100, 101-200, 200). Linear regression with generalized estimating equations were used to estimate the association between spaceflight exposures and CIMT. Results: 530 studies were completed among 213 astronauts with a mean of 2.5 studies (range 1-6) per astronaut over the six year period. As in other populations, CIMT was significantly associated with age; however, gender was not. While there was no significant direct correlation between total spaceflight exposure and CIMT found, astronauts with 30-100 spaceflight days and astronauts with greater than 100 spaceflight days had significantly increased CIMT over astronauts who had never flown (p=0.002 and p=<0.0001 respectively) after adjustment for age. Conclusion: Further work is needed to fully understand CIMT and its association to spaceflight. Current occupational surveillance activities are under way to study CIMT values in conjunction with other cardiovascular risk factors among astronauts as compared to the general population.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37929 , Annual Scientific Meeting of the Aerospace Medical Association; 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-11-23
    Description: Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing, the vestibular system and the central nervous system, responsible for coordinating head and eye movements via the vestibulo-occular reflex (VOR), are adapted to microgravity and must re-adapt to the Earth's gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. These effects are caused by retinal slip, or the inability to keep an image focused on their retina, which is thought to drive motion sickness symptoms experienced upon landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Peters et al. (2011) find that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. Previously, the use of stroboscopic goggles has shown to be effective in minimizing motion sickness symptoms due to retinal slip (Reschke et al. 2007). In this study, we simulated the decrement in DVA caused by sensorimotor re-adaptation by using minifying lenses and then testing the efficacy of stroboscopic goggles in preventing retinal slip and improving DVA. Dynamic visual acuity is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is motor-driven and oscillates vertically at 2 Hz with a vertical displacement of +/- 2 cm to simulate the vertical translations that occur while walking. As the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous responses of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. We found that healthy subjects (n=20) have a significantly impaired DVA while wearing the minifying lenses, demonstrating that the VOR is in an adaptive state and retinal slip is occurring. When subjects' acuity was tested wearing the stroboscopic goggles with the minifying lenses, there was no significant difference in their DVA compared to their baseline DVA. This suggests that stroboscopic goggles are preventing retinal slip and would function as an efficient countermeasure for VOR adaptations and thus help mitigate landing sickness symptoms experienced by long-duration crewmembers. These goggles might also be used to counter blurred vision (caused by retinal slip) experienced by crewmembers during launch where the vehicle vibrations are greatest. The stroboscopic effect could be built into a section of their head mounted displays on the visor of their helmets to be used in these high vibration situation if a mission critical task is necessary.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37995 , Human Research Program Investigators' Workshop; 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-23
    Description: Astronauts experience sensorimotor disturbances during their initial exposure to microgravity and during the re-adaptation phase following a return to an Earth-gravitational environment. These alterations may disrupt crewmembers' ability to perform mission critical functional tasks requiring ambulation, manual control and gaze stability. Interestingly, astronauts who return from spaceflight show substantial differences in their abilities to readapt to a gravitational environment. The ability to predict the manner and degree to which individual astronauts are affected will improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. For such an approach to succeed, we must develop predictive measures of sensorimotor adaptability that will allow us to foresee, before actual spaceflight, which crewmembers are likely to experience greater challenges to their adaptive capacities. The goals of this project are to identify and characterize this set of predictive measures. Our approach includes: 1) behavioral tests to assess sensory bias and adaptability quantified using both strategic and plastic-adaptive responses; 2) imaging to determine individual brain morphological and functional features, using structural magnetic resonance imaging (MRI), diffusion tensor imaging, resting state functional connectivity MRI, and sensorimotor adaptation task-related functional brain activation; and 3) assessment of genetic polymorphisms in the catechol-O-methyl transferase, dopamine receptor D2, and brain-derived neurotrophic factor genes and genetic polymorphisms of alpha2-adrenergic receptors that play a role in the neural pathways underlying sensorimotor adaptation. We anticipate that these predictive measures will be significantly correlated with individual differences in sensorimotor adaptability after long-duration spaceflight and exposure to an analog bed rest environment. We will be conducting a retrospective study, leveraging data already collected from relevant ongoing or completed bed rest and spaceflight studies. This data will be combined with predictor metrics that will be collected prospectively (as described for behavioral, brain imaging and genomic measures) from these returning subjects to build models for predicting post spaceflight and bed rest adaptive capability. In this presentation we will discuss the optimized set of tests for predictive metrics to be used for evaluating post mission adaptive capability as manifested in their outcome measures. Comparisons of model performance will allow us to better design and implement sensorimotor adaptability training countermeasures against decrements in post-mission adaptive capability that are customized for each crewmember's sensory biases, adaptive ability, brain structure, brain function, and genetic predispositions. The ability to customize adaptability training will allow more efficient use of crew time during training and will optimize training prescriptions for astronauts to mitigate the deleterious effects of spaceflight.
    Keywords: Behavioral Sciences ; Aerospace Medicine
    Type: JSC-CN-38005 , Human Research Program Investigators' Workshop ; 23-27 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-24
    Description: No abstract available
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-38103-2 , AIAA Non-Deterministic Approaches Conference; 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-11-24
    Description: Flying a mission in space requires a massive commitment of resources, and without the talent and commitment of the people involved in this effort we would never leave the atmosphere of Earth as safely as we have. When we use the phrase "humans in the loop", it could apply to almost any endeavor since everything starts with humans developing a concept, completing the design process, building or implementing a product and using the product to achieve a goal or purpose. Narrowing the focus to spaceflight, there are a variety of individuals involved throughout the preparations for flight and the flight itself. All of the humans involved add value and support for program success. The paper discusses the concepts of human involvement in technological programs, how a Probabilistic Risk Assessment (PRA) accounts for the human in the loop for potential missions using a technique called Human Reliability Analysis (HRA) and the tradeoffs between having a human in the loop or not. Human actions can increase or decrease the overall risk via initiating events or mitigating them, thus removing the human from the loop doesn't always lowers the risk.
    Keywords: Quality Assurance and Reliability ; Man/System Technology and Life Support
    Type: JSC-CN-38103-1 , AIAA Non-Deterministic Approaches Conference; 9-13 Jan. 2017; Grapevine, TX; United States
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  • Publication Date: 2016-11-24
    Description: Introduction: Microgravity exposure may alter the likelihood that astronauts will experience renal stones. The potential risk includes both acute and chronic health issues, with the potential for significant impact on mission objectives. Methods: To understand the role of the NASA's Human Research Program (HRP) research agenda in both preventing and addressing renal stones in spaceflight, current astronaut epidemiologic data and a summary of programmatic considerations are reviewed. Results: Although there has never been a symptomatic renal stone event in a U.S. crewmember during spaceflight, urine chemistry has been altered - likely due to induced changes in renal physiology as a result of exposure to microgravity. This may predispose astronauts to stone formation, leading the HRP to conduct and sponsor research to: 1) understand the risk of stone formation in space; 2) prevent stones from forming; and 3) address stones that may form by providing novel diagnostic and therapeutic approaches. Discussion: The development of a renal stone during spaceflight is a significant medical concern that requires the HRP to minimize this risk by providing the ability to prevent, diagnose, monitor and treat the condition during spaceflight. A discussion of the risk as NASA understands it is followed by an overview of the multiple mitigations currently under study, including novel ultrasound techniques for stone detection and manipulation, and how they may function as part of a larger exploration medical system.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37866 , Aerospace Medical Association (AsMA) Annual Scientific Meeting; 29 Apr. - 4 May 2017; Denver, CO; United States
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  • Publication Date: 2016-11-24
    Description: NASA astronauts on active status require medical certification for aircraft flying duties as well as readiness for long duration spaceflight training, launch to the International Space Station (ISS), and mission continuation during spaceflight operations. Behavioral fitness and adaptability is an inherent component of medical certification at NASA and requires a unique approach that spans the professional life-span of all active astronauts. TOPIC: This presentation will address the Behavioral Health and Performance (BHP) operations program at the Johnson Space Center. Components of BHP operations include astronaut selection, as well as annual, elective, preflight, inflight, and postflight BHP assessments. Each aspect of the BHP operations program will be discussed, with a focus on behavioral fitness determination and resultant outcomes. Specifically, astronaut selection generates a rating of suitability for long duration spaceflight as well as psychiatric qualification; annual, preflight and postflight BHP assessments provoke a decision regarding the presence of any aeromedical concerns; and inflight assessment requires a conclusion pertaining to mission impact. The combination of these elements provide for a unique, comprehensive approach to flight and spaceflight adaptability. APPLICATIONS: Attendees will understand the differing facets of NASA's comprehensive BHP operations program that occurs over the course of an astronaut's career and be able to compare and contrast this to the Adaptability Rating for Military Aviation (ARMA) and proposed models presented by others on this panel.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37844 , Aerospace Medical Association's 2017 Annual Scientific Meeting; 29 Apr. - 4 May 2017 ; Denver, CO; United States
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  • Publication Date: 2016-11-24
    Description: PURPOSE: Exploration space missions pose several challenges to providing a comprehensive medication formulary designed to accommodate the size and space limitations of the spacecraft; while addressing the individual medications needs and preferences of the Crew; the negative outcome of a degrading inventory over time, the inability to resupply before expiration dates; and the need to properly forecast the best possible medication candidates to treat conditions that will occur in the future. METHODS: The Pharmacotherapeutics Discipline has partnered with the Exploration Medical Capabilities (ExMC) Element to develop and propose a research pathway that is comprehensively focused on evidence-based models and theories, as well as on new diagnostic tools and treatments or preventive measures aimed at closure of the Med02 Pharmacy Gap; defined in the Human Research Programs (HRP) risk-based research strategy. The Med02 Gap promotes the challenge to identify a strategy to ensure that medications used to treat medical conditions during exploration space missions are available, safe, and effective. It is abundantly clear that pharmaceutical intervention is an essential component of risk management planning for astronaut healthcare during exploration space. However, the quandary still remains of how to assemble a formulary that is comprehensive enough to prevent or treat anticipated medical events; and is also chemically stable, safe, and robust enough to have sufficient potency to last for the duration of an exploration space mission. In cases where that is not possible, addressing this Gap requires exploration of novel drug development techniques, dosage forms, and dosage delivery platforms that enhance chemical stability as well as therapeutic effectiveness. RESULTS: The proposed research pathway outlines the steps, processes, procedures, and a research portfolio aimed at identifying a capability that will provide a safe and effective pharmacy for any specific exploration Design Reference Mission (DRM). The proposed approach to building this research portfolio is to seek research projects that concentrate on four major focus areas; (1) Formulary selection, (2) Formulary potency and shelf life, (3) Formulary safety and toxicity, and (4) Novel technology and innovation such as portable real-time chemical analysis innovative drug therapies and dosage and delivery platforms. CONCLUSION: The research pathway has been completed and presented to the HRP. In spring 2017, it is scheduled to be reviewed by a panel of pharmaceutical and clinical experts that will evaluate the scientific merit and operational feasibility of the research pathway, as well as make suggestions for any warranted additions or improvements. Once finalized, the ExMC Element will proceed with the execution of this research pathway with the goal of gathering as much data, and learning as much as possible, to provide a safe and effective pharmaceutical formulary for use during exploration missions.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37907 , Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-24
    Description: Over the past two years, the High Performance EVA Glove (HPEG) project under NASA's Space Technology Mission Directorate (STMD) funded an effort to develop an electromechanically-assisted space suit glove. The project was a collaboration between the Johnson Space Center's Software, Robotics, and Simulation Division and the Crew and Thermal Systems division. The project sought to combine finger actuator technology developed for Robonaut 2 with the softgoods from the ILC Phase VI EVA glove. The Space Suit RoboGlove (SSRG) uses a system of three linear actuators to pull synthetic tendons attached to the glove's fingers to augment flexion of the user's fingers. To detect the user's inputs, the system utilizes a combination of string potentiometers along the back of the fingers and force sensitive resistors integrated into the fingertips of the glove cover layer. This paper discusses the development process from initial concepts through two major phases of prototypes, and the results of initial human testing. Initial work on the project focused on creating a functioning proof of concept, designing the softgoods integration, and demonstrating augmented grip strength with the actuators. The second year of the project focused on upgrading the actuators, sensors, and software with the overall goal of creating a system that moves with the user's fingers in order to reduce fatigue associated with the operation of a pressurized glove system. This paper also discusses considerations for a flight system based on this prototype development and address where further work is required to mature the technology.
    Keywords: Cybernetics, Artificial Intelligence and Robotics ; Man/System Technology and Life Support
    Type: JSC-CN-37902 , 2017 International Conference on Environmental Systems; 16-20 Jul. 2017; Charleston, SC; United States
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  • Publication Date: 2016-11-24
    Description: Long-duration spaceflight results in sensorimotor adaptations, which cause functional deficits during gravitational transitions, such as landing on a planetary surface after long-duration microgravity exposure. Both the vestibular system and the central nervous system are affected by gravitational transitions. These systems are responsible for coordinating head and eye movements via the vestibulo-ocular reflex (VOR) and go through an adaptation period upon exposure to microgravity. Consequently, they must also re-adapt to Earth's gravitational environment upon landing. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with crewmembers reporting oscillopsia and blurred vision caused by retinal slip, or the inability to keep an image focused on their retina. This is thought to drive motion sickness symptoms experienced by most crewmembers following landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Previously, DVA has been assessed in the laboratory where subjects walked at 6.4 km/hr on a motorized treadmill. Using this method, Peters et al. (2011) found that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. However, it is believed that re-adaptation occurs quickly and that DVA might be worse immediately upon re-exposure to a gravitational environment. Since many crewmembers are unable to walk safely upon landing, it was necessary to develop a method for replicating the vertical head movements associated with walking. In addition, the use of a chair to imitate the head displacement caused by walking isolates eye-head interactions without allowing for trunk and lower-body compensation, as seen with treadmill walking (Mulavara & Bloomberg 2003). Therefore, a modality for assessing DVA in the field within a few hours of landing was developed. In this study, we validated the ability of a manually operated oscillating chair to reproduce the oscillatory frequency of walking on a treadmill. Healthy non-astronaut subjects (n=14) participated in one test session and completed three static (seated) and three dynamic (walking/oscillated) visual acuity tests. DVA was assessed using a motorized treadmill, an automated oscillating chair, and a manually operated chair, both developed in the Neuroscience Laboratory at JSC. The automated chair was motor-driven and set to oscillate vertically at 2 Hz with a vertical displacement of +/- 5 cm to simulate vertical translation while walking. The manually operated chair was oscillated vertically by a test operator to the beat of a metronome at 120 beats/min (2 Hz) and a vertical displacement of approximately +/- 5 cm. As the subject was oscillated, they were asked to discern the direction gap of Landolt-C optotypes of varying sizes and verbally reported the direction while an operator recorded their response using a gamepad. Subjects were outfitted with accelerometers (sampling rate = 128 Hz) on their head, trunk and lumbar spine. A fast Fourier transform was performed on the vertical trunk acceleration to compare the peak and spread of the distribution of oscillation frequencies for each oscillating condition. The spread of the frequency distribution for the manual chair was not significantly different from either the treadmill or the automated chair. However, all three conditions had similar non-zero standard error values, suggesting a variance in head movement frequency which may affect DVA. The average oscillation frequency of the manual chair (1.85 Hz) was significantly different (=0.05) from that of treadmill walking (2.24 Hz), but not significantly different from that of the automated chair (1.85 Hz) and all three conditions had small standard errors (SEM = 0.04, 0.06, and 0.08 Hz for manual, treadmill, and automated respectively). This implies that both chairs oscillate at a frequency below that of treadmill walking, but are comparable to each other and reproducible across sessions. Additionally, DVA scores did not vary significantly across conditions. The smaller spread values of the oscillating chairs' frequencies indicated mitigation of variation induced by locomotor strategies, which enables better examination of the issue of VOR adaptation. Furthermore, due to the deconditioned state of crewmembers in the initial hours after landing, it is easier to transport a manual bouncing chair into the field and safer to perform a vision test while seated in a chair versus walking on a treadmill. Therefore, the manually oscillating chair has been deemed to meet and exceed the DVA testing capabilities previously obtained by treadmill walking.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37992 , Human Research Program Investigators' Workshop; 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-23
    Description: This paper continues the annual tradition of summarizing at this conference the results of chemical analyses performed on archival potable water samples returned from the International Space Station (ISS). 2016 represented a banner year for life on board the ISS, including the successful conclusion for two crew members of a record one-year mission. Water reclaimed from urine and/or humidity condensate remained the primary source of potable water for the crew members of ISS Expeditions 46-50. The year 2016 was also marked by the end of a long-standing tradition of U.S. sampling and monitoring of Russian Segment potable water sources. Two water samples taken during Expedition 46 in February 2016 and returned on Soyuz 44, represented the final Russian Segment samples to be collected and analyzed by the U.S. side. Although anticipated for 2016, a rise in the total organic carbon (TOC) concentration of the product water from the U.S. water processor assembly due to breakthrough of organic contaminants from the system did not materialize, as evidenced by the onboard TOC analyzer and archive sample results.
    Keywords: Man/System Technology and Life Support
    Type: JSC-CN-37969 , International Conference on Environmental Systems ; 16-20 Apr. 2017; Charleston, SC; United States
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  • Publication Date: 2016-11-23
    Description: Introduction. This joint European Space Agency/NASA pre- and post-flight study investigates the influence of exposure to microgravity on the subjective straight ahead (SSA) in crewmembers returning from long-duration expeditions to the International Space Station (ISS). The SSA is a measure of the internal representation of body orientation and to be influenced by stimulation of sensory systems involved in postural control. The use of a vibrotactile sensory aid to correct the representation of body tilted relative to gravity is also tested as a countermeasure. This study addresses the sensorimotor research gap to "determine the changes in sensorimotor function over the course of a mission and during recovery after landing." Research Plans. The ISS study will involve eight crewmembers who will participate in three pre-flight sessions (between 120 and 60 days before launch) and then three post-flight sessions on R plus 0/1 day, R plus 4 days, and R plus 8 days. Sixteen control subjects were also tested during three sessions to evaluate the effects of repeated testing and to establish normative values. The experimental protocol includes measurements of gaze and arm movements during the following tasks: (1) Near & Far Fixation: The subject is asked to look at actual targets in the true straight-ahead direction or to imagine these targets in the dark. Targets are located at near distance (arm's length) and far distance (beyond 2 meters). This task is successively performed with the subject's body aligned with the gravitational vertical, and with the subject's body tilted in pitch relative to the gravitational vertical using a tilt chair. Measures are then compared with and without a vibrotactile sensory aid that indicates how far one has tilted relative to the vertical; (2) Eye and Arm Movements: The subject is asked to look and point in the SSA direction in darkness and then make horizontal and vertical eye or arm movements, relative to Earth coordinates (allocentric) and to the subject's head/body reference (egocentric). This task is successively performed with the subject's body aligned with the gravitational vertical, and with subject's body tilted in roll using a tilt chair; (3) Linear Vestibulo-Ocular Reflex: The subject is asked to fixate actual visual targets at near and far distances in the true straight-ahead direction, and to evaluate the distance of these targets. The subject is asked to continue fixating the same imagined targets in darkness while he/she is passively accelerated up and down on a spring-loaded vertical linear accelerator. Results. In the control subject population, the perceived tilt angles, translations, and distances were remarkably close to the actual values. The pointing tasks indicated that the orientation of arm saccades was influenced by both the gravitational vertical and the body idiotropic vector. Repeating the testing did not reveal any significant changes. Preliminary results obtained in three crewmembers before and after flight will also be presented. Applications. A change in an individual's egocentric reference might have negative consequences on evaluating the direction of an approaching object or on the accuracy of reaching movements or locomotion. Consequently, investigating how microgravity affects the target location will have theoretical, operational, and even clinical implications for future space exploration missions. The use of vibrotactile feedback as a sensorimotor countermeasure is applicable to balance therapy applications for patients with vestibular loss and the elderly to mitigate risks due to loss of spatial orientation.
    Keywords: Aerospace Medicine
    Type: JSC-CN-37991 , 2017 NASA Human Research Program Investigators' Workshop (HRP IWS 2017); 23-26 Jan. 2017; Galveston, TX; United States
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  • Publication Date: 2016-11-23
    Description: BACKGROUND: Future human space travel will consist primarily of long-duration missions onboard the International Space Station (ISS) or exploration-class missions to Mars, its moons, or nearby asteroids. Astronauts participating in long-duration missions may be at an increased risk of oxidative stress and inflammatory damage due to radiation, psychological stress, altered physical activity, nutritional insufficiency, and hyperoxia during extravehicular activity. By studying one identical twin during his 1-year ISS mission and his ground-based twin, this work extends a current NASA-funded investigation to determine whether these spaceflight factors contribute to an accelerated progression of atherosclerosis. This study of twins affords a unique opportunity to examine spaceflight-related atherosclerosis risk that is independent of the confounding factors associated with different genotypes. PURPOSE: The purpose of this investigation was to determine whether biomarkers of oxidative and inflammatory stress are elevated during and after long-duration spaceflight and determine if a relation exists between levels of these biomarkers and structural and functional indices of atherosclerotic risk measured in the carotid and brachial arteries. These physiological and biochemical data will be extended by using an exploratory approach to investigate the relationship between intermediate phenotypes and risk factors for atherosclerosis and the metabolomic signature from plasma and urine samples. Since metabolites are often the indirect products of gene expression, we simultaneously assessed gene expression and DNA methylation in leukocytes. HYPOTHESIS: We predict that, compared to the ground-based twin, the space-flown twin will experience elevated biomarkers of oxidative stress and inflammatory damage, altered arterial structure and function, accelerated telomere shortening, dysregulation of genes associated with oxidative stress and inflammation, and a metabolic profile shift that is associated with elevated atherosclerosis risk factors. METHODS: In the space-flown twin, a panel of biomarkers of oxidative and inflammatory stress were measured in venous blood samples and in 24-h (in-flight) and 48-h (pre- and post-flight) urine pools collected twice before flight, six times during the mission (~FD15, 75, 180, 240, 300, 335), and early in the post-flight recovery phase (3-5 days after landing). We also measured metabolomic (targeted and untargeted approaches) and genomic markers (DNA methylation, mRNA gene expression, telomere length) in these samples. Arterial structure, assessed from measures of intima-media thickness, also were measured using standard clinical ultrasound at the same time points. Arterial function was assessed using brachial flow-mediated dilation, a well-validated measure used to assess endothelium-dependent vasodilation and a sensitive predictor of atherosclerotic risk, only before and after spaceflight. All of the same measures were obtained in the ground-based twin, but less frequently. DISCUSSION: All data collection has been completed for both the space-flown twin and the ground-based twin. Vascular structure and function measures have been analyzed, blood and urine samples have been batch-processed. Results from these individuals will be compared to each other, to data from other Twin Study investigations, and to the larger complement of subjects participating in the companion study currently ongoing in ISS astronauts.
    Keywords: Aerospace Medicine