WorldWideScience

Sample records for advanced crew escape

  1. Cooling Properties of the Shuttle Advanced Crew Escape Spacesuit: Results of an Environmental Chamber Experiment

    Science.gov (United States)

    Hamilton, Douglas; Gillis, David; Bue, Grant; Son, Chan; Norcross, Jason; Kuznetz, Larry; Chapman, Kirt; Chhipwadia, Ketan; McBride, Tim

    2008-01-01

    The shuttle crew wears the Advanced Crew Escape Spacesuit (ACES) to protect themselves from cabin decompression and to support bail out during landing. ACES is cooled by a liquid-cooled garment (LCG) that interfaces to a heat exchanger that dumps heat into the cabin. The ACES outer layer is made of Gore-Tex(Registered TradeMark), permitting water vapor to escape while containing oxygen. The crew can only lose heat via insensible water losses and the LCG. Under nominal landing operations, the average cabin temperature rarely exceeds 75 F, which is adequate for the ACES to function. Problem A rescue shuttle will need to return 11 crew members if the previous mission suffers a thermal protection system failure, preventing it from returning safely to Earth. Initial analysis revealed that 11 crew members in the shuttle will increase cabin temperature at wheel stop above 80 F, which decreases the ACES ability to keep crew members cool. Air flow in the middeck of the shuttle is inhomogeneous and some ACES may experience much higher temperatures that could cause excessive thermal stress to crew members. Methods A ground study was conducted to measure the cooling efficiency of the ACES at 75 F, 85 F, and 95 F at 50% relative humidity. Test subjects representing 5, 50, and 95 percentile body habitus of the astronaut corps performed hand ergometry keeping their metabolic rate at 400, 600, and 800 BTU/hr for one hour. Core temperature was measured by rectal probe and skin, while inside and outside the suit. Environmental chamber wall and cooling unit inlet and outlet temperatures were measured using high-resolution thermistors ( 0.2 C). Conclusions Under these test conditions, the ACES was able to protect the core temperature of all test subjects, however thermal stress due to high insensible losses and skin temperature and skin heat flow may impact crew performance. Further research should be performed to understand the impact on cognitive performance.

  2. Modified Advanced Crew Escape Suit Intravehicular Activity Suit for Extravehicular Activity Mobility Evaluations

    Science.gov (United States)

    Watson, Richard D.

    2014-01-01

    The use of an intravehicular activity (IVA) suit for a spacewalk or extravehicular activity (EVA) was evaluated for mobility and usability in the Neutral Buoyancy Laboratory (NBL) environment at the Sonny Carter Training Facility near NASA Johnson Space Center in Houston, Texas. The Space Shuttle Advanced Crew Escape Suit was modified to integrate with the Orion spacecraft. The first several missions of the Orion Multi-Purpose Crew Vehicle will not have mass available to carry an EVA-specific suit; therefore, any EVA required will have to be performed by the Modified Advanced Crew Escape Suit (MACES). Since the MACES was not designed with EVA in mind, it was unknown what mobility the suit would be able to provide for an EVA or whether a person could perform useful tasks for an extended time inside the pressurized suit. The suit was evaluated in multiple NBL runs by a variety of subjects, including crewmembers with significant EVA experience. Various functional mobility tasks performed included: translation, body positioning, tool carrying, body stabilization, equipment handling, and tool usage. Hardware configurations included with and without Thermal Micrometeoroid Garment, suit with IVA gloves and suit with EVA gloves. Most tasks were completed on International Space Station mock-ups with existing EVA tools. Some limited tasks were completed with prototype tools on a simulated rocky surface. Major findings include: demonstrating the ability to weigh-out the suit, understanding the need to have subjects perform multiple runs prior to getting feedback, determining critical sizing factors, and need for adjusting suit work envelope. Early testing demonstrated the feasibility of EVA's limited duration and limited scope. Further testing is required with more flight-like tasking and constraints to validate these early results. If the suit is used for EVA, it will require mission-specific modifications for umbilical management or Primary Life Support System integration

  3. Advanced Thermal Status Control of Crews in EVA and Escape Suits

    Science.gov (United States)

    Koscheyev, V. S.; Coca, A.; Leon, G. R.

    Over the course of the manned space program, there has been an accumulation of experience on methods to control the thermal status of astronauts in open space. However, there remains a significant need for a simple method to monitor the astronaut's level of heat exchange during EVA, particularly in an emergency period, or during crew escape. The liquid cooling/warming tubing system that covers the body surface creates considerable complexity for evaluating the body's overall thermal response. Moreover, the methods used to monitor core temperature (Tc) are problematic in regard to their invasiveness and accuracy. NASA is currently attempting to develop a unified methodology for protection during EVA and crew escape that would necessarily include the control of astronaut thermal status. The findings from our research program have significant implications for solving this still-vexing problem. Our experimental paradigm centers on the assessment of thermodynamic processes with subjects donned in a specially designed symmetrically divided multi-compartment liquid cooling/warming garment consisting of 16 zones, 8 on each side of the body (hands, forearms, shoulders, torso, head, thighs, calves and feet). This garment configuration enables the study of heat exchange under nonuniform temperatures on the body surface by systematically varying the proportions of nonuniform temperatures (warm/cold) in different experimental conditions. Tc was assessed by rectal (Tr), esophageal (Tes), and ear canal temperature (Tec). Skin temperature (Tsk) was measured by a total of 26 sensors placed symmetrically on the left and right sides of the body, the main magistral vessels (carotid, brachial, femoral), and local vessel networks. We paid particular attention to the thermal status of the fingers by measuring blood perfusion, temperature (Tfing), heat flux, and thermal/comfort perception. The monitoring of Tfing and heat flux in different experimental conditions was highly informative

  4. Comparison of spacecraft crew escape systems through dynamic optimization

    Science.gov (United States)

    Hart, William G., III

    Crew escape systems have been a vital component of ensuring safety onboard manned spacecraft. Although there have been only a few aborts involving their use, their operation helps decrease risk in what is known to be a hazardous field. But despite their high reliability, crew escape systems typically suffer from heavy weight, lack of control and hazardous chemical propellants. Hybrid propulsion systems could be a viable solution to all of these problems. With their inert components, ability to throttle and higher specific impulse than solids, hybrids have obtained interest in recent years. This dissertation presents a method that can be used to compare solid and hybrid propulsion systems for the crew escape systems of spacecraft. The concepts of dynamic optimization, Monte Carlo simulation and propulsion system design are combined to produce a tool which can predict the probability of survival for a given abort scenario. The method can also determine the effect of uncertain variables, such as reaction time or the payload of the vehicle, in the safety of the crew. The method is then used to compare crew escape systems for two separate vehicles: a separable crew cabin proposed for the Space Shuttle Launch Vehicle and the Launch Escape System for the Crew Exploration Vehicle scheduled to begin operation in 2012. The effects of uncertain parameters are also studied. The results show the utility of this method and the objective function, and how it could be used in the design process for future space vehicles.

  5. Serial Escape System For Aircraft Crews

    Science.gov (United States)

    Wood, Kenneth E.

    1990-01-01

    Emergency escape system for aircraft and aerospace vehicles ejects up to seven crewmembers, one by one, within 120 s. Intended for emergencies in which disabled craft still in stable flight at no more than 220 kn (113 m/s) equivalent airspeed and sinking no faster than 110 ft/s (33.5 m/s) at altitudes up to 50,000 ft (15.2 km). Ejection rockets load themselves from magazine after each crewmember ejected. Jumpmaster queues other crewmembers and helps them position themselves on egress ramp. Rockets pull crewmembers clear of aircraft structure. Provides orderly, controlled exit and avoids ditching at sea or landing in rough terrain.

  6. STS-45 payload specialists with crew escape system (CES) mockup at JSC's MAIL

    Science.gov (United States)

    1991-01-01

    STS-45 Atlantis, Orbiter Vehicle (OV) 104, Payload Specialist Dirk D. Frimout (European Space Agency (ESA) Belgian crewmember) (left), backup Payload Specialist Charles R. Chappell (center), and Payload Specialist Byron K. Lichtenberg (right) listen to technician explain the operation of the crew escape system (CES) pole. Frimout is engaging the handle which extends the CES pole out the side hatch. The payload specialists along with the other STS-45 crewmembers are participating in side hatch emergency egress exercises in JSC's Mockup and Integration Laboratory (MAIL) Bldg 9A.

  7. Interim results of the study of control room crew staffing for advanced passive reactor plants

    Energy Technology Data Exchange (ETDEWEB)

    Hallbert, B.P.; Sebok, A.; Haugset, K. [OECD Halden Reactor Project (Norway)

    1996-03-01

    Differences in the ways in which vendors expect the operations staff to interact with advanced passive plants by vendors have led to a need for reconsideration of the minimum shift staffing requirements of licensed Reactor Operators and Senior Reactor Operators contained in current federal regulations (i.e., 10 CFR 50.54(m)). A research project is being carried out to evaluate the impact(s) of advanced passive plant design and staffing of control room crews on operator and team performance. The purpose of the project is to contribute to the understanding of potential safety issues and provide data to support the development of design review guidance. Two factors are being evaluated across a range of plant operating conditions: control room crew staffing; and characteristics of the operating facility itself, whether it employs conventional or advanced, passive features. This paper presents the results of the first phase of the study conducted at the Loviisa nuclear power station earlier this year. Loviisa served as the conventional plant in this study. Data collection from four crews were collected from a series of design basis scenarios, each crew serving in either a normal or minimum staffing configuration. Results of data analyses show that crews participating in the minimum shift staffing configuration experienced significantly higher workload, had lower situation awareness, demonstrated significantly less effective team performance, and performed more poorly as a crew than the crews participating in the normal shift staffing configuration. The baseline data on crew configurations from the conventional plant setting will be compared with similar data to be collected from the advanced plant setting, and a report prepared providing the results of the entire study.

  8. STS-26 crew trains in JSC crew compartment trainer (CCT) shuttle mockup

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, Commander Frederick H. Hauck tests cushion outside the crew compartment trainer (CCT) side hatch. Hauck, wearing new (navy blue) partial pressure suit (launch and entry suit (LES)) and helmet, tumbles out CCT side hatch onto cushion as technicians look on. During Crew Station Review (CSR) #3, the crew donned the new partial pressure suits and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. CCT is located in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A.

  9. Fifty years of chasing lizards: new insights advance optimal escape theory.

    Science.gov (United States)

    Samia, Diogo S M; Blumstein, Daniel T; Stankowich, Theodore; Cooper, William E

    2016-05-01

    Systematic reviews and meta-analyses often examine data from diverse taxa to identify general patterns of effect sizes. Meta-analyses that focus on identifying generalisations in a single taxon are also valuable because species in a taxon are more likely to share similar unique constraints. We conducted a comprehensive phylogenetic meta-analysis of flight initiation distance in lizards. Flight initiation distance (FID) is a common metric used to quantify risk-taking and has previously been shown to reflect adaptive decision-making. The past decade has seen an explosion of studies focused on quantifying FID in lizards, and, because lizards occur in a wide range of habitats, are ecologically diverse, and are typically smaller and differ physiologically from the better studied mammals and birds, they are worthy of detailed examination. We found that variables that reflect the costs or benefits of flight (being engaged in social interactions, having food available) as well as certain predator effects (predator size and approach speed) had large effects on FID in the directions predicted by optimal escape theory. Variables that were associated with morphology (with the exception of crypsis) and physiology had relatively small effects, whereas habitat selection factors typically had moderate to large effect sizes. Lizards, like other taxa, are very sensitive to the costs of flight.

  10. Blowout win : advances in BOP technology cut waste and make work safer for drilling crews

    Energy Technology Data Exchange (ETDEWEB)

    Budd, G.

    2008-03-15

    With the advent of programmable logic controllers (PLCs), there has been significant improvement in the way that blowout prevention (BOP) equipment can be controlled and operated. The accumulator, which provides the energy to operate the BOP, usually includes compressed gas bottles, regulator valves, pumps, a hydraulic reservoir, a manifold, and control valves. PLCs have made the accumulator easier to operate since they have eliminated much of the cable that spans from the control panel to the rig control shack. The control unit currently consists of some computer chips and a printed circuit instead of miles of wires and cables. In addition to providing efficient BOP control, PLCs have enabled rig managers to readily identify and fix problems. Some manufacturers have included remote troubleshooting capability for the accumulator. Advances in BOP technology and controls have been driven by the challenges of drilling in harsh offshore environments. However, some operators in the Western Canadian Sedimentary Basin continue to use BOP systems that have been around for decades because of their reputation for reliability and low-maintenance requirements. 1 fig.

  11. Crew Escape Technologies (CREST) Mission Area Requirements Study Current and Future Crew Escape Requirements

    Science.gov (United States)

    1992-02-01

    anthropometry and the type and location of the equipment worn by the test suboect. Based upon the data taken In the early nineteen sixties it was...3.1.1 of the CREST Specification describes the system as having -Flow stagnation fence to reduce windblast Induced loads on the head, torso and upper

  12. Putting Integrated Systems Health Management Capabilities to Work: Development of an Advanced Caution and Warning System for Next-Generation Crewed Spacecraft Missions

    Science.gov (United States)

    Mccann, Robert S.; Spirkovska, Lilly; Smith, Irene

    2013-01-01

    Integrated System Health Management (ISHM) technologies have advanced to the point where they can provide significant automated assistance with real-time fault detection, diagnosis, guided troubleshooting, and failure consequence assessment. To exploit these capabilities in actual operational environments, however, ISHM information must be integrated into operational concepts and associated information displays in ways that enable human operators to process and understand the ISHM system information rapidly and effectively. In this paper, we explore these design issues in the context of an advanced caution and warning system (ACAWS) for next-generation crewed spacecraft missions. User interface concepts for depicting failure diagnoses, failure effects, redundancy loss, "what-if" failure analysis scenarios, and resolution of ambiguity groups are discussed and illustrated.

  13. STS-26 crew in JSC Shuttle Mockup and Integration Laboratory Bldg 9A

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers model the new (navy blue) partial pressure suits (launch and entry suits (LESs)) for entry and launch phases before a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Pictured (left to right) are Mission Specialist (MS) David C. Hilmers, Commander Frederick H. Hauck, Pilot Richard O. Covey, MS John M. Lounge, and MS George D. Nelson. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  14. STS-26 crew in JSC Shuttle Mockup and Integration Laboratory

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers have donned their new (navy blue) partial pressure suits (launch and entry suits (LESs)) for a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Commander Frederick H. Hauck is in the center foreground. Hauck is flanked by fellow crewmembers (left to right) Mission Specialist (MS) John M. Lounge, MS George D. Nelson, Pilot Richard O. Covey, and MS David C. Hilmers. Astronaut Steven R. Nagel, not assigned as crewmember but assisting in training, is at far right. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  15. STS-26 crew trains in JSC full fuselage trainer (FFT) shuttle mockup

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers are briefed during a training exercise in the Shuttle Mockup and Integration Laboratory Bldg 9A. Seated outside the open side hatch of the full fuselage trainer (FFT) (left to right) are Mission Specialist (MS) George D. Nelson, Commander Frederick H. Hauck, and Pilot Richard O. Covey. Astronaut Steven R. Nagel (left), positioned in the open side hatch, briefs the crew on the pole escape system as he demonstrates some related equipment. During Crew Station Review (CSR) #3, the crew donned the new (navy blue) partial pressure suits (launch and entry suits (LESs)) and checked out crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options. The photograph was taken by Keith Meyers of the NEW YORK TIMES.

  16. Commercial Crew Program Crew Safety Strategy

    Science.gov (United States)

    Vassberg, Nathan; Stover, Billy

    2015-01-01

    The purpose of this presentation is to explain to our international partners (ESA and JAXA) how NASA is implementing crew safety onto our commercial partners under the Commercial Crew Program. It will show them the overall strategy of 1) how crew safety boundaries have been established; 2) how Human Rating requirements have been flown down into programmatic requirements and over into contracts and partner requirements; 3) how CCP SMA has assessed CCP Certification and CoFR strategies against Shuttle baselines; 4) Discuss how Risk Based Assessment (RBA) and Shared Assurance is used to accomplish these strategies.

  17. Methodology and algorithms for railway crew management

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, R.; Gomide, F. [State Univ. of Campinas, SP (Brazil). Faculty of Electrical and Computer Engineering; Lagrimante, R. [MRS Logistica S.A, Juiz de Fora, MG (Brazil)

    2000-07-01

    Crew management problems are highly important for many transportation systems such as airlines, railways and public bus transportation. Despite recent advances, scheduling methodologies and decision support systems still need improvement, especially their computational efficiency, practical feasibility and use. This paper briefly overview classic crew management approaches. It discusses various practical issues concerning classic methods and suggests a new approach and algorithms. Computational results and experience with actual data and real world situations are also reported. (orig.)

  18. Atmospheric escape, redox evolution, and planetary habitability

    Science.gov (United States)

    Catling, D. C.; Zahnle, K. J.

    2011-12-01

    Through the greenhouse effect, the presence and composition of an atmosphere is critical for defining a (conventional) circumstellar habitable zone in terms of planetary surface temperatures suitable for liquid water. Lack of knowledge of planetary atmospheres is likely to frustrate attempts to say with any certainty whether detected terrestrial-sized exoplanets may or may not be habitable. Perhaps an underappreciated role in such considerations is the evolutionary effect of atmospheric escape for determining atmospheric composition or whether an atmosphere exists in the first place. Whether atmospheres exist at all on planets is demonstrably connected to the effect of integrated atmospheric escape. When we observe our own Solar System and transiting exoplanets, the existence of an atmosphere is clearly delineated by a relative vulnerability to thermal escape and impact erosion. The prevalence of thermal escape as a key evolutionary determinant for the presence of planetary atmosphere is shown by a relationship between the relative solar (or stellar) heating and the escape velocity. Those bodies with too much stellar heating and too smaller escape velocity end up devoid of atmospheres. Impact erosion is evident in the relationship between impact velocity and escape velocity. Escape due to impacts is particularly important for understanding the large differences in the atmospheres of giant planet moons, such as Ganymede versus Titan. It is also significant for Mars-sized planets. The oxidation state of atmospheres is important for some theories of the origin of life (where an early reducing atmosphere is helpful for organic synthesis) and the evolution of advanced life (where free molecular oxygen is the best source of high energy metabolism). Surfaces on some relatively small planets and moons are observed to have evolved to an oxidized state, which theory and observation can explain through atmospheric escape. There are several examples in the Solar System where a

  19. STS-47 Crew Briefing

    Science.gov (United States)

    1992-01-01

    The crew of STS-47, Commander Robert L. Gibson, Pilot Curtis L. Brown, Payload Commander Mark C. Lee, Mission Specialists N. Jan Davis, Jay Apt, and Mae C. Jemison, and Payload Specialist Mamoru Mohri answer questions from the press about the upcoming Endeavour mission and the crew's personal views of the mission.

  20. Commercial Crew Medical Ops

    Science.gov (United States)

    Heinbaugh, Randall; Cole, Richard

    2016-01-01

    Provide commercial partners with: center insight into NASA spaceflight medical experience center; information relative to both nominal and emergency care of the astronaut crew at landing site center; a basis for developing and sharing expertise in space medical factors associated with returning crew.

  1. STS-26 crew training in JSC Shuttle Mockup and Integration Laboratory Bldg 9A

    Science.gov (United States)

    1988-01-01

    STS-26 Discovery, Orbiter Vehicle (OV) 103, crewmembers use a bit of orchestrated humor to demonstrate the aft (back) zipper feature on the new (navy blue) partial pressure suits (launch and entry suits (LESs)) before a training exercise in JSC's Shuttle Mockup and Integration Laboratory Bldg 9A. Left to right are Commander Frederick H. Hauck, Mission Specialist (MS) George D. Nelson, MS David C. Hilmers, MS John M. Lounge, and Pilot Richard O. Covey. During Crew Station Review (CSR) #3, the crew is scheduled to check out the new partial pressure suits and crew escape system (CES) configurations to evaluate crew equipment and procedures related to emergency egress methods and proposed crew escape options.

  2. Crew Transportation Plan

    Science.gov (United States)

    Zeitler, Pamela S. (Compiler); Mango, Edward J.

    2013-01-01

    The National Aeronautics and Space Administration (NASA) Commercial Crew Program (CCP) has been chartered to facilitate the development of a United States (U.S.) commercial crew space transportation capability with the goal of achieving safe, reliable, and cost effective access to and from low Earth orbit (LEO) and the International Space Station (ISS) as soon as possible. Once the capability is matured and is available to the Government and other customers, NASA expects to purchase commercial services to meet its ISS crew rotation and emergency return objectives.

  3. GASA Hybird Algorithm Applied in Airline Crew Rostering System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yinghui; RAO Yunbo; ZHOU Mingtian

    2007-01-01

    Crew postering system is a daily grind in the management of both corporation and enterprise. A fair and reasonable rostering method plays a very important role in the arousing worker's enthusiasm and improving the work efficiency. This paper presents a method of building models for automatic crew rostering mode with computer and advancing the multi-objective optimum scheme. The method to build models for crew rostering system is also discussed. The question to crew rostering system model is solved by genetic algorithms and simulated annealing algorithms. Simulation results show the correctness of algorithms. The actual data of the airways have justified its reasonability and efficiency.

  4. Crew Transportation Operations Standards

    Science.gov (United States)

    Mango, Edward J.; Pearson, Don J. (Compiler)

    2013-01-01

    The Crew Transportation Operations Standards contains descriptions of ground and flight operations processes and specifications and the criteria which will be used to evaluate the acceptability of Commercial Providers' proposed processes and specifications.

  5. Escape in Hill's Problem

    CERN Document Server

    Heggie, D C

    2000-01-01

    This didactic paper is motivated by the problem of understanding how stars escape from globular star clusters. One formulation of this problem is known, in dynamical astronomy, as Hill's problem. Originally intended as a model for the motion of the moon around the earth with perturbations by the sun, with simple modifications it also serves as a model for the motion of a star in a star cluster with perturbations by the galaxy. The paper includes introductory sections on the derivation of the equations of motion of Hill's problem, their elementary properties, and extensions to deal with non-point masses and non-circular orbits. We then show how the rate of escape may be calculated numerically and estimated theoretically, and discuss how this simple picture is modified if the stars in a cluster are also undergoing two-body relaxation. Finally we introduce some established ideas for obtaining the distribution of escape times.

  6. Coordination strategies of crew management

    Science.gov (United States)

    Conley, Sharon; Cano, Yvonne; Bryant, Don

    1991-01-01

    An exploratory study that describes and contrasts two three-person flight crews performing in a B-727 simulator is presented. This study specifically attempts to delineate crew communication patterns accounting for measured differences in performance across routine and nonroutine flight patterns. The communication patterns in the two crews evaluated indicated different modes of coordination, i.e., standardization in the less effective crew and planning/mutual adjustment in the more effective crew.

  7. Formulation of consumables management models: Consumables analysis/crew simulator interface requirements

    Science.gov (United States)

    Zamora, M. A.

    1977-01-01

    Consumables analysis/crew training simulator interface requirements were defined. Two aspects were investigated: consumables analysis support techniques to crew training simulator for advanced spacecraft programs, and the applicability of the above techniques to the crew training simulator for the space shuttle program in particular.

  8. Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Launch Abort System (LAS) for the Orion Crew Exploration Vehicle (CEV) will provide a safe escape for the crew in the event of an emergency during launch. A key...

  9. Getting a Crew into Orbit

    Science.gov (United States)

    Riddle, Bob

    2011-01-01

    Despite the temporary setback in our country's crewed space exploration program, there will continue to be missions requiring crews to orbit Earth and beyond. Under the NASA Authorization Act of 2010, NASA should have its own heavy launch rocket and crew vehicle developed by 2016. Private companies will continue to explore space, as well. At the…

  10. Crew decision making under stress

    Science.gov (United States)

    Orasanu, J.

    1992-01-01

    Flight crews must make decisions and take action when systems fail or emergencies arise during flight. These situations may involve high stress. Full-missiion flight simulation studies have shown that crews differ in how effectively they cope in these circumstances, judged by operational errors and crew coordination. The present study analyzed the problem solving and decision making strategies used by crews led by captains fitting three different personality profiles. Our goal was to identify more and less effective strategies that could serve as the basis for crew selection or training. Methods: Twelve 3-member B-727 crews flew a 5-leg mission simulated flight over 1 1/2 days. Two legs included 4 abnormal events that required decisions during high workload periods. Transcripts of videotapes were analyzed to describe decision making strategies. Crew performance (errors and coordination) was judged on-line and from videotapes by check airmen. Results: Based on a median split of crew performance errors, analyses to date indicate a difference in general strategy between crews who make more or less errors. Higher performance crews showed greater situational awareness - they responded quickly to cues and interpreted them appropriately. They requested more decision relevant information and took into account more constraints. Lower performing crews showed poorer situational awareness, planning, constraint sensitivity, and coordination. The major difference between higher and lower performing crews was that poorer crews made quick decisions and then collected information to confirm their decision. Conclusion: Differences in overall crew performance were associated with differences in situational awareness, information management, and decision strategy. Captain personality profiles were associated with these differences, a finding with implications for crew selection and training.

  11. A Lucky Escape

    Institute of Scientific and Technical Information of China (English)

    王道庚

    2009-01-01

    @@ This story concerns(有关)a spider(蜘蛛)and a certain general of ancient times who had lost a battle and,in the company of(在……陪同下)a faithful(忠诚的)servant,was trying to escape(逃脱)from the enemy.Both were extremely(极度,非常)tired,and both were hungry and thirsty,but they did not dare to go into any town for fear of (担心,害怕)being discovered and captured(捉)by the enemy.Toward evening they arrived at a mountain where there was a small cave.

  12. STS-99 Crew Insignia

    Science.gov (United States)

    1999-01-01

    The STS-99 crew members designed the flight insignia for the Shuttle Radar Topography Mission (SRTM), the most ambitious Earth mapping mission to date. Two radar anternas, one located in the Shuttle bay and the other located on the end of a 60-meter deployable mast, was used during the mission to map Earth's features. The goal was to provide a 3-dimensional topographic map of the world's surface up to the Arctic and Antarctic Circles. In the patch, the clear portion of Earth illustrates the radar beams penetrating its cloudy atmosphere and the unique understanding of the home planet that is provided by space travel. The grid on Earth reflects the mapping character of the SRTM mission. The patch depicts the Space Shuttle Endeavour orbiting Earth in a star spangled universe. The rainbow along Earth's horizon resembles an orbital sunrise. The crew deems the bright colors of the rainbow as symbolic of the bright future ahead because of human beings' venturing into space. The crew of six launched aboard the Space Shuttle Endeavor on February 11, 2000 and completed 222 hours of around the clock radar mapping gathering enough information to fill more than 20,000 CDs.

  13. Escape from the Alternative

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2006-12-01

    Full Text Available This paper sets out to elaborate on Romania’s specific agenda regarding the approach to the integration process in the EU as a project of modernization. The focus is on the functional aspects, the type of strategic solutions destined to consolidate the specific transformations belonging to post-communist transition seen as an internal transition, on the one hand and on the other hand to push convergence as the essence of integration, marked by the vision of EU integration as a continuation of change, which is the stage of external transition. Identifying the prominent factors and the pragmatic priorities of the escape from the peripheries of development by engaging in evolution by way of the second modernization constitutes as well a target for analysis. One particularity of the method of analysis is the review if the value-set of the bobsled effect of path dependency – the path of the peripheries – as well as of the set of values of the escape from the peripheries.

  14. Crew Systems Laboratory/Building 7. Historical Documentation

    Science.gov (United States)

    Slovinac, Patricia

    2011-01-01

    Building 7 is managed by the Crew and Thermal Systems Division of the JSC Engineering Directorate. Originally named the Life Systems Laboratory, it contained five major test facilities: two advanced environmental control laboratories and three human-rated vacuum chambers (8 , 11 , and the 20 ). These facilities supported flight crew familiarization and the testing and evaluation of hardware used in the early manned spaceflight programs, including Gemini, Apollo, and the ASTP.

  15. Mars - an escaping planet?

    CERN Document Server

    Dvorak, R

    2005-01-01

    The chaotic behaviour of the motion of the planets in our Solar System is well established. Numerical experiments with a modified Solar System consisting of a more massive Earth have shown, that for special values of an enlargement factor K around 5 the dynamical state of a truncated planetary system (excluding Mercury and the outer planets Uranus and Neptune) is highly chaotic. On the contrary for values of the mass of the Earth up to the mass of Saturn no irregular dynamical behaviour was observed. We extended our investigations to the complete planetary system and showed, that this chaotic window found before still exists. Tests in different 'Solar Systems' showed that only including Jupiter and Saturn with their actual masses together with a 'massive' Earth (between 4 and 6 times more massive) destabilize the orbit of Mars so that even escapes from the system are possible.

  16. The advancement of a new human factors report--'The Unique Report'--facilitating flight crew auditing of performance/operations as part of an airline's safety management system.

    Science.gov (United States)

    Leva, M C; Cahill, J; Kay, A M; Losa, G; McDonald, N

    2010-02-01

    This paper presents the findings of research relating to the specification of a new human factors report, conducted as part of the work requirements for the Human Integration into the Lifecycle of Aviation Systems project, sponsored by the European Commission. Specifically, it describes the proposed concept for a unique report, which will form the basis for all operational and safety reports completed by flight crew. This includes all mandatory and optional reports. Critically, this form is central to the advancement of improved processes and technology tools, supporting airline performance management, safety management, organisational learning and knowledge integration/information-sharing activities. Specifically, this paper describes the background to the development of this reporting form, the logic and contents of this form and how reporting data will be made use of by airline personnel. This includes a description of the proposed intelligent planning process and the associated intelligent flight plan concept, which makes use of airline operational and safety analyses information. Primarily, this new reporting form has been developed in collaboration with a major Spanish airline. In addition, it has involved research with five other airlines. Overall, this has involved extensive field research, collaborative prototyping and evaluation of new reports/flight plan concepts and a number of evaluation activities. Participants have included both operational and management personnel, across different airline flight operations processes. Statement of Relevance: This paper presents the development of a reporting concept outlined through field research and collaborative prototyping within an airline. The resulting reporting function, embedded in the journey log compiled at the end of each flight, aims at enabling employees to audit the operations of the company they work for.

  17. Crew Transportation Technical Management Processes

    Science.gov (United States)

    Mckinnie, John M. (Compiler); Lueders, Kathryn L. (Compiler)

    2013-01-01

    Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document, with its sister documents, International Space Station (ISS) Crew Transportation and Services Requirements Document (CCT-REQ-1130), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), Crew Transportation Operations Standards (CCT STD-1150), and ISS to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase.

  18. Apollo 15 Crew Portrait

    Science.gov (United States)

    1971-01-01

    This is the official three-member crew portrait of the Apollo 15 (SA-510). Pictured from left to right are: David R. Scott, Mission Commander; Alfred M. Worden Jr., Command Module pilot; and James B. Irwin, Lunar Module pilot. The fifth marned lunar landing mission, Apollo 15 (SA-510), lifted off on July 26, 1971. Astronauts Scott and Irwin were the first to use a wheeled surface vehicle, the Lunar Roving Vehicle (LRV), or the Rover, which was designed and developed by the Marshall Space Flight Center, and built by the Boeing Company. The astronauts spent 13 days, nearly 67 hours, on the Moon's surface to inspect a wide variety of its geological features.

  19. Crew Interviews: Treschev

    Science.gov (United States)

    2002-01-01

    Sergei Treschev is a Cosmonaut of the Rocket Space Corporation Energia, (RSC), from Volynsky District, Lipetsk Region (Russia). He graduated from Moscow Energy Institute. After years of intense training with RSC Energia, he was selected as International Space Station (ISS) Increment 5 flight engineer. The Expedition-Five crew (two Russian cosmonauts and one American astronaut) will stay on the station for approximately 5 months. The Multipurpose Logistics Module, or MPLM, will carry experiment racks and three stowage and resupply racks to the station. The mission will also install a component of the Canadian Arm called the Mobile Base System (MBS) to the Mobile Transporter (MT) installed during STS-110. This completes the Canadian Mobile Servicing System, or MSS. The mechanical arm will now have the capability to "inchworm" from the U.S. Lab fixture to the MSS and travel along the Truss to work sites.

  20. STS-69 Crew members display 'Dog Crew' patches

    Science.gov (United States)

    1995-01-01

    Following their arrival at KSC's Shuttle Landing Facility, the five astronauts assigned to Space Shuttle Mission STS-69 display the unofficial crew patch for their upcoming spaceflight: the Dog Crew II patch. Mission Commander David M. Walker (center) and Payload Commander James S. Voss (second from right) previously flew together on Mission STS-53, the final dedicated Department of Defense flight on the Space Shuttle. A close comradery formed among Walker, Voss and the rest of the crew, and they dubbed themselves the 'dogs of war', with each of the STS-53 'Dog Crew' members assigned a 'dog tag' or nickname. When the STS-69 astronauts also became good buddies, they decided it was time for the Dog Crew II to be named. Walker's dog tag is Red Dog, Voss's is Dogface, Pilot Kenneth D. Cockrell (second from left) is Cujo, space rookie and Mission Specialist Michael L. Gernhardt (left) is Under Dog, and Mission Specialist James H. Newman (right) is Pluato. The Dog Crew II patch features a bulldog peering out from a doghouse shaped like the Space Shuttle and lists the five crew member's dog names. The five astronauts are scheduled to lift off on the fifth Shuttle flight of the year at 11:04 a.m. EDT, August 31, aboard the Space Shuttle Endeavour.

  1. An escape from crowding.

    Science.gov (United States)

    Freeman, Jeremy; Pelli, Denis G

    2007-10-26

    Crowding occurs when nearby flankers jumble the appearance of a target object, making it hard to identify. Crowding is feature integration over an inappropriately large region. What determines the size of that region? According to bottom-up proposals, the size is that of an anatomically determined isolation field. According to top-down proposals, the size is that of the spotlight of attention. Intriligator and Cavanagh (2001) proposed the latter, but we show that their conclusion rests on an implausible assumption. Here we investigate the role of attention in crowding using the change blindness paradigm. We measure capacity for widely and narrowly spaced letters during a change detection task, both with and without an interstimulus cue. We find that standard crowding manipulations-reducing spacing and adding flankers-severely impair uncued change detection but have no effect on cued change detection. Because crowded letters look less familiar, we must use longer internal descriptions (less compact representations) to remember them. Thus, fewer fit into working memory. The memory limit does not apply to the cued condition because the observer need remember only the cued letter. Cued performance escapes the effects of crowding, as predicted by a top-down account. However, our most parsimonious account of the results is bottom-up: Cued change detection is so easy that the observer can tolerate feature degradation and letter distortion, making the observer immune to crowding. The change detection task enhances the classic partial report paradigm by making the test easier (same/different instead of identifying one of many possible targets), which increases its sensitivity, so it can reveal degraded memory traces.

  2. Escape rates for Gibbs measures

    CERN Document Server

    Ferguson, Andrew

    2010-01-01

    We study the asymptotic behaviour of the escape rate of a Gibbs measure supported on a conformal repeller through a small hole. There are additional applications to the convergence of Hausdorff dimension of the survivor set.

  3. Direction of escape in reindeer

    OpenAIRE

    Baskin, Leonid M.; Terje Skogland

    1997-01-01

    We tested the hypothesis that reindeer prefer to run uphill and upwind when escaping from man. Groups of wild and feral reindeer in Norway, Svalbard and on Wrangel Island were approached and their behaviour and direction of escape were recorded. Two stages of interaction with man were studied: first flight and final withdrawal. First flights proved to be away from man, upwind and uphill. Most final withdrawals were in the direction reindeer were moving when first observed.

  4. Direction of escape in reindeer

    Directory of Open Access Journals (Sweden)

    Leonid M. Baskin

    1997-04-01

    Full Text Available We tested the hypothesis that reindeer prefer to run uphill and upwind when escaping from man. Groups of wild and feral reindeer in Norway, Svalbard and on Wrangel Island were approached and their behaviour and direction of escape were recorded. Two stages of interaction with man were studied: first flight and final withdrawal. First flights proved to be away from man, upwind and uphill. Most final withdrawals were in the direction reindeer were moving when first observed.

  5. Flight Crew Integration (FCI) ISS Crew Comments Database & Products Summary

    Science.gov (United States)

    Schuh, Susan

    2016-01-01

    This Crew Debrief Data provides support for design and development of vehicles, hardware, requirements, procedures, processes, issue resolution, lessons learned, consolidation and trending for current Programs; and much of the data is also used to support development of future Programs.

  6. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II SBIR proposal is aimed at developing a non-invasive, optical method for monitoring crew member state of awareness in operational environments. All...

  7. Crew Cerebral Oxygen Monitor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase I SBIR proposal is aimed at developing a non-invasive, optical method for monitoring the state of consciousness of crew members in operational...

  8. STS-29 Discovery, OV-103, MS Springer on JSC crew compartment trainer middeck

    Science.gov (United States)

    1989-01-01

    STS-29 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Robert C. Springer, wearing navy blue launch and entry suit (LES) and launch and entry helmet (LEH), participates in JSC crew compartment trainer (CCT) exercises. MS Springer is seated in mission specialist seat on CCT middeck, the position he will occupy during the entry phase of flight. Behind Springer is the closed airlock hatch and stowed treadmill. The crew escape system (CES) pole extends overhead from starboard wall to side hatch. On Springer's left is the galley. CCT is located in JSC Mockup and Integration Laboratory Bldg 9A. Photo was taken by Bill Bowers of JSC.

  9. Submarine Escape Set Test Facilities

    Directory of Open Access Journals (Sweden)

    G.S.N. Murthy

    2009-07-01

    Full Text Available Submarine Escape Set (SES is used by submariners to escape from a sunken submarine. This set caters for breathing needs of the submariner under water, until he reaches the surface. Evaluation of such life-saving equipment is of paramount importance. This paper describes the submarine escape set and various constructional features and schedules of operation of test facilities designed indegenously and which can evaluate the SES. The test facility is divided into two parts: the reducer test facility, and the breathing bag test facility. The equipment has been rigorously tested and accepted by Indian Navy. Two such test facilities have been developed, one of which is installed at INS Satavahana, Visakhapatnam, and are working satisfactorily.

  10. DYNAMICS OF THE ESCAPE RESPONSE.

    Science.gov (United States)

    requirements. It has been shown that force is a lawful response measure under positive reinforcement (Notterman and Mintz, 1965). Subjects will adjust...concluded that response force in an escape situation is a lawful response measure, and that it operates in a manner similar to force under positive reinforcement .

  11. Commercial Crew Development Program Overview

    Science.gov (United States)

    Russell, Richard W.

    2011-01-01

    NASA's Commercial Crew Development Program is designed to stimulate efforts within the private sector that will aid in the development and demonstration of safe, reliable, and cost-effective space transportation capabilities. With the goal of delivery cargo and eventually crew to Low Earth Orbit (LEO) and the International Space Station (ISS) the program is designed to foster the development of new spacecraft and launch vehicles in the commercial sector. Through Space Act Agreements (SAAs) in 2011 NASA provided $50M of funding to four partners; Blue Origin, The Boeing Company, Sierra Nevada Corporation, and SpaceX. Additional, NASA has signed two unfunded SAAs with ATK and United Space Alliance. This paper will give a brief summary of these SAAs. Additionally, a brief overview will be provided of the released version of the Commercial Crew Development Program plans and requirements documents.

  12. STS-88 crew goes through Crew Equipment Interface Testing

    Science.gov (United States)

    1998-01-01

    -- In the Orbiter Processing Facility Bay 1, STS-88 Mission Specialists (left to right) Jerry L. Ross; Sergei Krikalev, a cosmonaut from Russia; and James H. Newman examine equipment that will be on the Space Shuttle Endeavour during their upcoming flight. Launch of Mission STS-88 is targeted for Dec. 3, 1998. The STS-88 crew members are participating in a Crew Equipment Interface Test (CEIT), familiarizing themselves with the orbiter's midbody and crew compartments. Other crew members are Commander Robert D. Cabana, Pilot Frederick W. 'Rick' Sturckow and Mission Specialist Nancy J. Currie. STS-88 will be the first Space Shuttle launch for assembly of the International Space Station (ISS). The primary payload is the Unity connecting module which will be mated to the Russian-built Zarya control module, expected to be already on orbit after a November launch from Russia. The first major U.S.-built component of ISS, Unity will serve as a connecting passageway to living and working areas of the space station. Unity has two attached pressurized mating adapters (PMAs) and one stowage rack installed inside. PMA-1 provides the permanent connection point between Unity and Zarya; PMA-2 will serve as a Space Shuttle docking port. Zarya is a self-supporting active vehicle, providing propulsive control capability and power during the early assembly stages. It also has fuel storage capability.

  13. Cold Ion Escape from Mars

    Science.gov (United States)

    Fränz, M.; Dubinin, E.; Wei, Y.; Morgan, D.; Andrews, D.; Barabash, S.; Lundin, R.; Fedorov, A.

    2013-09-01

    It has always been challenging to observe the flux of ions with energies of less than 10eV escaping from the planetary ionospheres. We here report on new measurements of the ionospheric ion flows at Mars by the ASPERA-3 experiment on board Mars Express in combination with the MARSIS radar experiment. We first compare calculations of the mean ion flux observed by ASPERA-3 alone with previously published results. We then combine observations of the cold ion velocity by ASPERA-3 with observations of the cold plasma density by MARSIS since ASPERA-3 misses the cold core of the ion distribution. We show that the mean density of the nightside plasma observed by MARSIS is about two orders higher than observed by ASPERA-3 (Fig.1). Combining both datasets we show that the main escape channel is along the shadow boundary on the tailside of Mars (Fig. 2). At a distance of about 0.5 R_M the flux settles at a constant value (Fig. 3) which indicates that about half of the transterminator ionospheric flow escapes from the planet. Possible mechanism to generate this flux can be the ionospheric pressure gradient between dayside and nightside or momentum transfer from the solar wind via the induced magnetic field since the flow velocity is in the Alfvénic regime.

  14. 46 CFR 185.420 - Crew training.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Crew training. 185.420 Section 185.420 Shipping COAST...) OPERATIONS Crew Requirements § 185.420 Crew training. (a) The owner, charterer, master or managing operator... duties listed in the station bill required by § 185.514 of this part. (b) Training conducted on a...

  15. ESCAPE AS REINFORCEMENT AND ESCAPE EXTINCTION IN THE TREATMENT OF FEEDING PROBLEMS

    OpenAIRE

    LaRue, Robert H; Stewart, Victoria; Piazza, Cathleen C; Volkert, Valerie M.; Patel, Meeta R; Zeleny, Jason

    2011-01-01

    Given the effectiveness of putative escape extinction as treatment for feeding problems, it is surprising that little is known about the effects of escape as reinforcement for appropriate eating during treatment. In the current investigation, we examined the effectiveness of escape as reinforcement for mouth clean (a product measure of swallowing), escape as reinforcement for mouth clean plus escape extinction (EE), and EE alone as treatment for the food refusal of 5 children. Results were si...

  16. Data link air traffic control and flight deck environments: Experiment in flight crew performance

    Science.gov (United States)

    Lozito, Sandy; Mcgann, Alison; Corker, Kevin

    1993-01-01

    This report describes an experiment undertaken in a full mission simulation environment to investigate the performance impact of, and human/system response to, data-linked Air Traffic Control (ATC) and automated flight deck operations. Subjects were twenty pilots (ten crews) from a major United States air carrier. Crews flew the Advanced Concepts Flight Simulator (ACFS), a generic 'glass cockpit' simulator at NASA Ames. The method of data link used was similar to the data link implementation plans for a next-generation aircraft, and included the capability to review ATC messages and directly enter ATC clearance information into the aircraft systems. Each crew flew experimental scenarios, in which data reflecting communication timing, errors and clarifications, and procedures were collected. Results for errors and clarifications revealed an interaction between communication modality (voice v. data link) and communication type (air/ground v. intracrew). Results also revealed that voice crews initiated ATC contact significantly more than data link crews. It was also found that data link crews performed significantly more extraneous activities during the communication task than voice crews. Descriptive data from the use of the review menu indicate the pilot-not-flying accessing the review menu most often, and also suggest diffulty in accessing the target message within the review menu structure. The overall impact of communication modality upon air/ground communication and crew procedures is discussed.

  17. Photochemical Escape of Oxygen from Early Mars

    CERN Document Server

    Zhao, Jinjin

    2015-01-01

    Photochemical escape is an important process for oxygen escape from present Mars. In this work, a 1-D Monte-Carlo Model is developed to calculate escape rates of energetic oxygen atoms produced from O2+ dissociative recombination reactions (DR) under 1, 3, 10, and 20 times present solar XUV fluxes. We found that although the overall DR rates increase with solar XUV flux almost linearly, oxygen escape rate increases from 1 to 10 times present solar XUV conditions but decreases when increasing solar XUV flux further. Analysis shows that atomic species in the upper thermosphere of early Mars increases more rapidly than O2+ when increasing XUV fluxes. While the latter is the source of energetic O atoms, the former increases the collision probability and thus decreases the escape probability of energetic O. Our results suggest that photochemical escape be a less important escape mechanism than previously thought for the loss of water and/or CO2 from early Mars.

  18. Energy-limited escape revised

    CERN Document Server

    Salz, M; Czesla, S; Schmitt, J H M M

    2016-01-01

    Gas planets in close proximity to their host stars experience photoevaporative mass loss. The energy-limited escape concept is generally used to derive estimates for the planetary mass-loss rates. Our photoionization hydrodynamics simulations of the thermospheres of hot gas planets show that the energy-limited escape concept is valid only for planets with a gravitational potential lower than $\\log_\\mathrm{10}\\left( -\\Phi_{\\mathrm{G}}\\right) < 13.11~$erg$\\,$g$^{-1}$ because in these planets the radiative energy input is efficiently used to drive the planetary wind. Massive and compact planets with $\\log_\\mathrm{10}\\left( -\\Phi_{\\mathrm{G}}\\right) \\gtrsim 13.6~$erg$\\,$g$^{-1}$ exhibit more tightly bound atmospheres in which the complete radiative energy input is re-emitted through hydrogen Ly$\\alpha$ and free-free emission. These planets therefore host hydrodynamically stable thermospheres. Between these two extremes the strength of the planetary winds rapidly declines as a result of a decreasing heating eff...

  19. ISS Crew Transportation and Services Requirements Document

    Science.gov (United States)

    Lueders, Kathryn L. (Compiler)

    2015-01-01

    Under the guidance of processes provided by Crew Transportation Plan (CCT-PLN-1100), this document with its sister documents, Crew Transportation Technical Management Processes (CCT-PLN-1120), Crew Transportation Technical Standards and Design Evaluation Criteria (CCT-STD-1140), and Crew Transportation Operations Standards (CCT-STD-1150), and International Space Station (ISS) to Commercial Orbital Transportation Services Interface Requirements Document (SSP 50808), provides the basis for a National Aeronautics and Space Administration (NASA) certification for services to the ISS for the Commercial Provider. When NASA Crew Transportation System (CTS) certification is achieved for ISS transportation, the Commercial Provider will be eligible to provide services to and from the ISS during the services phase of the NASA Commercial Crew Program (CCP).

  20. Escape as Reinforcement and Escape Extinction in the Treatment of Feeding Problems

    Science.gov (United States)

    LaRue, Robert H.; Stewart, Victoria; Piazza, Cathleen C.; Volkert, Valerie M.; Patel, Meeta R.; Zeleny, Jason

    2011-01-01

    Given the effectiveness of putative escape extinction as treatment for feeding problems, it is surprising that little is known about the effects of escape as reinforcement for appropriate eating during treatment. In the current investigation, we examined the effectiveness of escape as reinforcement for mouth clean (a product measure of…

  1. Kuiper Prize Lecture - Escape of atmospheres, ancient and modern

    Energy Technology Data Exchange (ETDEWEB)

    Hunten, D.M. (Arizona Univ., Tucson (USA))

    1990-05-01

    A development history is presented for theories concerning planetary atmosphere gas-escape phenomena, which although firmly grounded in the kinetics of gases achieved truly productive results only after spacecraft remote sensing data for both the earth atmosphere and the planets became widely available. The most significant initial advances, encompassing diffusion-limited flow, nonthermal escape mechanisms, bound nonthermal coronas, and mass fractionation during early blowoff, followed from sounding rocket studies of the earth upper atmosphere, Mariner 5 results on hydrogen near Venus, and the nitrogen isotopic composition discovered by Viking in Mars. Attention has more recently been given to the xenon isotopic patterns in various atmospheres, as well as to the puzzling behavior of the Io atmosphere and plasma torus. 126 refs.

  2. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    Da Dao-an; Yang Ya-tian

    2005-12-01

    The escape rate of atmospheric molecules on the Moon is calculated.Based on the assumption that the rates of emission and escape of gases attain equilibrium, the ratio of molecular number densities during day and night, 0/0, can be explained. The plausible emission rate of helium and radioactive elements present in the Moon has also been calculated.

  3. Escaping in Literature. Teaching in the Library.

    Science.gov (United States)

    Hurst, Carol Otis

    1993-01-01

    Explores the "escape" genre of children's literature, and recommends and describes several books that deal with such topics as escape from prison camps, from slavery, from the Holocaust, from war, and from Utopian societies. These books should provoke meaningful classroom discussions and allow children to view their own world from different…

  4. Statin escape phenomenon: Fact or fiction?

    Science.gov (United States)

    Barkas, Fotios; Elisaf, Moses; Klouras, Eleftherios; Dimitriou, Theodora; Tentolouris, Nikolaos; Liberopoulos, Evangelos

    2017-01-01

    AIM To evaluate the presence of the so called “statin escape” phenomenon among hyperlipidemic subjects attending a lipid clinic. METHODS This was a retrospective analysis of 1240 hyperlipidemic individuals followed-up for ≥ 3 years. We excluded those individuals meeting one of the following criteria: Use of statin therapy at baseline visit, discontinuation of statin treatment at most recent visit, change in statin treatment during follow-up and poor compliance to treatment. Statin escape phenomenon was defined as an increase in low-density lipoprotein cholesterol (LDL-C) levels at the most recent visit by > 10% compared with the value at 6 mo following initiation of statin treatment. RESULTS Of 181 eligible subjects, 31% exhibited the statin escape phenomenon. No major differences regarding baseline characteristics were found between statin escapers and non-statin escapers. Both escapers and non-escapers had similar baseline LDL-C levels [174 (152-189) and 177 (152-205) mg/dL, respectively]. In comparison with non-escapers, statin escapers demonstrated lower LDL-C levels at 6 mo after treatment initiation [88 (78-97) mg/dL vs 109 (91-129) mg/dL, P statin-treated individuals. The clinical significance of this phenomenon remains uncertain.

  5. Crew Management in Passenger Rail Transport

    NARCIS (Netherlands)

    E.J.W. Abbink (Erwin)

    2014-01-01

    textabstract__Abstract__ Crew management in passenger rail transport is an important factor that contributes to both the quality of service to the railway passengers and to the operational costs of the train operating company. This thesis describes how the (railway) Crew Management process can be i

  6. Optimal escape theory predicts escape behaviors beyond flight initiation distance: risk assessment and escape by striped plateau lizards Sceloporus virgatus

    Institute of Scientific and Technical Information of China (English)

    William E.COOPER Jr

    2009-01-01

    Escape theory predicts that flight initiation distance (FID=distance between predator and prey when escape begins) is longer when risk is greater and shorter when escape is more costly. A few tests suggest that escape theory applies to distance fled. Escape models have not addressed stochastic variables, such as probability of fleeing and of entering refuge, but their economic logic might be applicable. Experiments on several risk factors in the lizard Sceloporus virgatus confirmed all predictions for the above escape variables. FID was greater when approach was faster and more direct, for lizards on ground than on trees, for lizards rarely exposed to humans, for the second of two approaches, and when the predator turned toward lizards rather than away. Lizards fled further during rapid and second consecutive approaches. They were more likely to flee when approached directly, when a predator turned toward them, and during second approaches. They were more likely to enter refuge when approached rapidly. A novel finding is that perch height in trees was unrelated to FID because lizards escaped by moving out of sight, then moving up or down unpredictably. These findings add to a growing body of evidence supporting predictions of escape theory for FID and distance fled. They show that two probabilistic aspects of escape are predictable based on relative predation risk levels. Because individuals differ in boldness, the assessed optimal FID and threshold risks for fleeing and entering refuge are exceeded for an increasing proportion of individuals as risk increases[Current Zoology 55(2):123-131,2009].

  7. Crew Transportation System Design Reference Missions

    Science.gov (United States)

    Mango, Edward J.

    2015-01-01

    Contains summaries of potential design reference mission goals for systems to transport humans to andfrom low Earth orbit (LEO) for the Commercial Crew Program. The purpose of this document is to describe Design Reference Missions (DRMs) representative of the end-to-end Crew Transportation System (CTS) framework envisioned to successfully execute commercial crew transportation to orbital destinations. The initial CTS architecture will likely be optimized to support NASA crew and NASA-sponsored crew rotation missions to the ISS, but consideration may be given in this design phase to allow for modifications in order to accomplish other commercial missions in the future. With the exception of NASA’s mission to the ISS, the remaining commercial DRMs are notional. Any decision to design or scar the CTS for these additional non-NASA missions is completely up to the Commercial Provider. As NASA’s mission needs evolve over time, this document will be periodically updated to reflect those needs.

  8. The Apollo 11 Prime Crew

    Science.gov (United States)

    1969-01-01

    Portrait of the prime crew of the Apollo 11 lunar landing mission. From left to right they are: Commander, Neil A. Armstrong, Command Module Pilot, Michael Collins, and Lunar Module Pilot, Edwin E. Aldrin Jr. On July 20th 1969 at 4:18 PM, EDT the Lunar Module 'Eagle' landed in a region of the Moon called the Mare Tranquillitatis, also known as the Sea of Tranquillity. After securing his spacecraft, Armstrong radioed back to earth: 'Houston, Tranquility Base here, the Eagle has landed'. At 10:56 p.m. that same evening and witnessed by a worldwide television audience, Neil Armstrong stepped off the 'Eagle's landing pad onto the lunar surface and said: 'That's one small step for a man, one giant leap for mankind.' He became the first human to set foot upon the Moon.

  9. STS-112 Crew Interviews: Ashby

    Science.gov (United States)

    2002-01-01

    STS-112 Mission Commander Jeffrey Ashby is seen during this preflight interview, answering questions about his inspiration in becoming an astronaut and his career path and provides an overview of the mission. Ashby outlines his role in the mission in general, and specifically during the docking and extravehicular activities (EVAs). He describes the payload (S1 truss) and the importance that the S1 truss will have in the development of the International Space Station (ISS). Ashby discusses the delivery and installation of the S1 truss scheduled to be done in the planned EVAs in some detail. He touches on the use and operation of the Canadarm 2 robotic arm in this process and outlines what supplies will be exchanged with the resident crew of the ISS during transfer activities. He ends with his thoughts on the value of the ISS in fostering international cooperation.

  10. Biomedical Wireless Ambulatory Crew Monitor

    Science.gov (United States)

    Chmiel, Alan; Humphreys, Brad

    2009-01-01

    A compact, ambulatory biometric data acquisition system has been developed for space and commercial terrestrial use. BioWATCH (Bio medical Wireless and Ambulatory Telemetry for Crew Health) acquires signals from biomedical sensors using acquisition modules attached to a common data and power bus. Several slots allow the user to configure the unit by inserting sensor-specific modules. The data are then sent real-time from the unit over any commercially implemented wireless network including 802.11b/g, WCDMA, 3G. This system has a distributed computing hierarchy and has a common data controller on each sensor module. This allows for the modularity of the device along with the tailored ability to control the cards using a relatively small master processor. The distributed nature of this system affords the modularity, size, and power consumption that betters the current state of the art in medical ambulatory data acquisition. A new company was created to market this technology.

  11. STS-112 Crew Interviews: Yurchikhin

    Science.gov (United States)

    2002-01-01

    A preflight interview with mission specialist Fyodor Yurchikhin is presented. He worked for a long time in Energia in the Russian Mission Control Center (MCC). Yurchikhin discusses the main goal of the STS-112 flight, which is to install the Integrated Truss Assembly S1 (Starboard Side Thermal Radiator Truss) on the International Space Station. He also talks about the three space walks required to install the S1. After the installation of S1, work with the bolts and cameras are performed. Yurchikhin is involved in working with nitrogen and ammonia jumpers. He expresses the complexity of his work, but says that he and the other crew members are ready for the challenge.

  12. FRAMEWORK AND APPLICATION FOR MODELING CONTROL ROOM CREW PERFORMANCE AT NUCLEAR POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    Ronald L Boring; David I Gertman; Tuan Q Tran; Brian F Gore

    2008-09-01

    This paper summarizes an emerging project regarding the utilization of high-fidelity MIDAS simulations for visualizing and modeling control room crew performance at nuclear power plants. The key envisioned uses for MIDAS-based control room simulations are: (i) the estimation of human error associated with advanced control room equipment and configurations, (ii) the investigative determination of contributory cognitive factors for risk significant scenarios involving control room operating crews, and (iii) the certification of reduced staffing levels in advanced control rooms. It is proposed that MIDAS serves as a key component for the effective modeling of cognition, elements of situation awareness, and risk associated with human performance in next generation control rooms.

  13. Orion Crew Exploration Vehicle Launch Abort System Guidance and Control Analysis Overview

    Science.gov (United States)

    Davidson, John B.; Kim, Sungwan; Raney, David L.; Aubuchon, Vanessa V.; Sparks, Dean W.; Busan, Ronald C.; Proud, Ryan W.; Merritt, Deborah S.

    2008-01-01

    Aborts during the critical ascent flight phase require the design and operation of Orion Crew Exploration Vehicle (CEV) systems to escape from the Crew Launch Vehicle (CLV) and return the crew safely to the Earth. To accomplish this requirement of continuous abort coverage, CEV ascent abort modes are being designed and analyzed to accommodate the velocity, altitude, atmospheric, and vehicle configuration changes that occur during ascent. Aborts from the launch pad to early in the flight of the CLV second stage are performed using the Launch Abort System (LAS). During this type of abort, the LAS Abort Motor is used to pull the Crew Module (CM) safely away from the CLV and Service Module (SM). LAS abort guidance and control studies and design trades are being conducted so that more informed decisions can be made regarding the vehicle abort requirements, design, and operation. This paper presents an overview of the Orion CEV, an overview of the LAS ascent abort mode, and a summary of key LAS abort analysis methods and results.

  14. Quantifying Distributions of Lyman Continuum Escape Fraction

    CERN Document Server

    Cen, Renyue

    2015-01-01

    Simulations have indicated that most of the escaped Lyman continuum photons escape through a minority of solid angles with near complete transparency, with the remaining majority of the solid angles largely opaque, resulting in a very broad and skewed probability distribution function (PDF) of the escape fraction when viewed at different angles. Thus, the escape fraction of Lyman continuum photons of a galaxy observed along a line of sight merely represents the properties of the interstellar medium along that line of sight, which may be an ill-representation of true escape fraction of the galaxy averaged over its full sky. Here we study how Lyman continuum photons escape from galaxies at $z=4-6$, utilizing high-resolution large-scale cosmological radiation-hydrodynamic simulations. We compute the PDF of the mean escape fraction ($\\left$) averaged over mock observational samples, as a function of the sample size, compared to the true mean (had you an infinite sample size). We find that, when the sample size is...

  15. AMO EXPRESS: A Command and Control Experiment for Crew Autonomy

    Science.gov (United States)

    Stetson, Howard K.; Frank, Jeremy; Cornelius, Randy; Haddock, Angie; Wang, Lui; Garner, Larry

    2015-01-01

    NASA is investigating a range of future human spaceflight missions, including both Mars-distance and Near Earth Object (NEO) targets. Of significant importance for these missions is the balance between crew autonomy and vehicle automation. As distance from Earth results in increasing communication delays, future crews need both the capability and authority to independently make decisions. However, small crews cannot take on all functions performed by ground today, and so vehicles must be more automated to reduce the crew workload for such missions. NASA's Advanced Exploration Systems Program funded Autonomous Mission Operations (AMO) project conducted an autonomous command and control demonstration of intelligent procedures to automatically initialize a rack onboard the International Space Station (ISS) with power and thermal interfaces, and involving core and payload command and telemetry processing, without support from ground controllers. This autonomous operations capability is enabling in scenarios such as a crew medical emergency, and representative of other spacecraft autonomy challenges. The experiment was conducted using the Expedite the Processing of Experiments for Space Station (EXPRESS) rack 7, which was located in the Port 2 location within the U.S Laboratory onboard the International Space Station (ISS). Activation and deactivation of this facility is time consuming and operationally intensive, requiring coordination of three flight control positions, 47 nominal steps, 57 commands, 276 telemetry checks, and coordination of multiple ISS systems (both core and payload). The autonomous operations concept includes a reduction of the amount of data a crew operator is required to verify during activation or de-activation, as well as integration of procedure execution status and relevant data in a single integrated display. During execution, the auto-procedures provide a step-by-step messaging paradigm and a high level status upon termination. This

  16. Asteroid Redirect Crewed Mission Space Suit and EVA System Architecture Trade Study

    Science.gov (United States)

    Blanco, Raul A.; Bowie, Jonathan T.; Watson, Richard D.; Sipila, Stephanie A.

    2014-01-01

    the Advanced Crew Escape Suit (ACES), and the Exploration Z-suit. For this mission, the pressure garment that was selected is the Modified ACES (MACES) with EVA enhancements. Life support options that were considered included short closed-loop umbilicals, long open-loop umbilicals, the currently in-use ISS EMU Portable Life Support System (PLSS), and the currently in development Exploration PLSS. For this mission, the life support option that was selected is the Exploration PLSS. The greatest risk in the proposed architecture is viewed to be the comfort and mobility of the baseline MACES and the delicate balance between adding more mobility features while not compromising landing safety. Feasibility testing was accomplished in low fidelity analogs and in the JSC Neutral Buoyancy Laboratory (NBL) to validate the concept before a final recommendation on the architecture was made. The proposed architecture was found to meet the mission constraints, but much more work is required to determine the details of the required suit upgrades, the integration with the PLSS, and the rest of the tools and equipment required to accomplish the mission. This work and further definition of the remaining kits will be conducted in government fiscal year 14.

  17. Group interaction and flight crew performance

    Science.gov (United States)

    Foushee, H. Clayton; Helmreich, Robert L.

    1988-01-01

    The application of human-factors analysis to the performance of aircraft-operation tasks by the crew as a group is discussed in an introductory review and illustrated with anecdotal material. Topics addressed include the function of a group in the operational environment, the classification of group performance factors (input, process, and output parameters), input variables and the flight crew process, and the effect of process variables on performance. Consideration is given to aviation safety issues, techniques for altering group norms, ways of increasing crew effort and coordination, and the optimization of group composition.

  18. The escape velocity and Schwarzschild metric

    CERN Document Server

    Murzagalieva, A G; Murzagaliev, G Z

    2002-01-01

    The escape velocity value in the terms of general relativity by means Schwarzschild metric is provided to make of the motion equation with Friedman cosmological model behavior build in the terms of Robertson-Worker metric. (author)

  19. Polymer escape from a confining potential

    Energy Technology Data Exchange (ETDEWEB)

    Mökkönen, Harri, E-mail: harri.mokkonen@aalto.fi [Department of Applied Physics and COMP CoE, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo (Finland); Faculty of Physical Sciences, University of Iceland, Reykjavík (Iceland); Ikonen, Timo [Department of Applied Physics and COMP CoE, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo (Finland); VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044 VTT (Finland); Jónsson, Hannes [Department of Applied Physics and COMP CoE, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo (Finland); Faculty of Physical Sciences, University of Iceland, Reykjavík (Iceland); Department of Physics, Brown University, Providence, Rhode Island 02912-1843 (United States); Ala-Nissila, Tapio [Department of Applied Physics and COMP CoE, Aalto University School of Science, P.O. Box 11100, FIN-00076 Aalto, Espoo (Finland); Department of Physics, Brown University, Providence, Rhode Island 02912-1843 (United States)

    2014-02-07

    The rate of escape of polymers from a two-dimensionally confining potential well has been evaluated using self-avoiding as well as ideal chain representations of varying length, up to 80 beads. Long timescale Langevin trajectories were calculated using the path integral hyperdynamics method to evaluate the escape rate. A minimum is found in the rate for self-avoiding polymers of intermediate length while the escape rate decreases monotonically with polymer length for ideal polymers. The increase in the rate for long, self-avoiding polymers is ascribed to crowding in the potential well which reduces the free energy escape barrier. An effective potential curve obtained using the centroid as an independent variable was evaluated by thermodynamic averaging and Kramers rate theory then applied to estimate the escape rate. While the qualitative features are well reproduced by this approach, it significantly overestimates the rate, especially for the longer polymers. The reason for this is illustrated by constructing a two-dimensional effective energy surface using the radius of gyration as well as the centroid as controlled variables. This shows that the description of a transition state dividing surface using only the centroid fails to confine the system to the region corresponding to the free energy barrier and this problem becomes more pronounced the longer the polymer is. A proper definition of a transition state for polymer escape needs to take into account the shape as well as the location of the polymer.

  20. Crew Autonomy Measures and Models (CAMM) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — SA Technologies will employ a two-part solution including measures and models for evaluating crew autonomy in exploratory space missions. An integrated measurement...

  1. Flight Crew State Monitoring Metrics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — eSky will develop specific crew state metrics based on the timeliness, tempo and accuracy of pilot inputs required by the H-mode Flight Control System (HFCS)....

  2. Flight Activity and Crew Tracking System -

    Data.gov (United States)

    Department of Transportation — The Flight Activity and Crew Tracking System (FACTS) is a Web-based application that provides an overall management and tracking tool of FAA Airmen performing Flight...

  3. STS-47 Astronaut Crew Training Clip

    Science.gov (United States)

    1992-01-01

    The crew of STS-47, Commander Robert L. Gibson, Pilot Curtis L. Brown, Payload Commander Mark C. Lee, Mission Specialists N. Jan Davis, Jay Apt, and Mae C. Jemison, and Payload Specialist Mamoru Mohri, is seen during various parts of their training, including SAREX training in the Full Fuselage Trainer (FFT), firefighting training. A familiarization flight in the KC-135, a food tasting, photo training in the Crew Compartment Trainer, and bailout training in the Weightless Environment Training Facility (WETF) are also shown.

  4. 20 CFR 404.1010 - Farm crew leader as employer.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Farm crew leader as employer. 404.1010....1010 Farm crew leader as employer. A farm crew leader furnishes workers to do agricultural labor for another person, usually a farm operator. If the crew leader pays the workers (the money can be the...

  5. International Space Station Crew Return Vehicle: X-38. Educational Brief.

    Science.gov (United States)

    National Aeronautics and Space Administration, Washington, DC.

    The International Space Station (ISS) will provide the world with an orbiting laboratory that will have long-duration micro-gravity experimentation capability. The crew size for this facility will depend upon the crew return capability. The first crews will consist of three astronauts from Russia and the United States. The crew is limited to three…

  6. Crew-Aided Autonomous Navigation

    Science.gov (United States)

    Holt, Greg N.

    2015-01-01

    A sextant provides manual capability to perform star/planet-limb sightings and offers a cheap, simple, robust backup navigation source for exploration missions independent from the ground. Sextant sightings from spacecraft were first exercised in Gemini and flew as the lost-communication backup for all Apollo missions. This study characterized error sources of navigation-grade sextants for feasibility of taking star and planetary limb sightings from inside a spacecraft. A series of similar studies was performed in the early/mid-1960s in preparation for Apollo missions. This study modernized and updated those findings in addition to showing feasibility using Linear Covariance analysis techniques. The human eyeball is a remarkable piece of optical equipment and provides many advantages over camera-based systems, including dynamic range and detail resolution. This technique utilizes those advantages and provides important autonomy to the crew in the event of lost communication with the ground. It can also provide confidence and verification of low-TRL automated onboard systems. The technique is extremely flexible and is not dependent on any particular vehicle type. The investigation involved procuring navigation-grade sextants and characterizing their performance under a variety of conditions encountered in exploration missions. The JSC optical sensor lab and Orion mockup were the primary testing locations. For the accuracy assessment, a group of test subjects took sextant readings on calibrated targets while instrument/operator precision was measured. The study demonstrated repeatability of star/planet-limb sightings with bias and standard deviation around 10 arcseconds, then used high-fidelity simulations to verify those accuracy levels met the needs for targeting mid-course maneuvers in preparation for Earth reen.

  7. Genes that escape from X inactivation.

    Science.gov (United States)

    Berletch, Joel B; Yang, Fan; Xu, Jun; Carrel, Laura; Disteche, Christine M

    2011-08-01

    To achieve a balanced gene expression dosage between males (XY) and females (XX), mammals have evolved a compensatory mechanism to randomly inactivate one of the female X chromosomes. Despite this chromosome-wide silencing, a number of genes escape X inactivation: in women about 15% of X-linked genes are bi-allelically expressed and in mice, about 3%. Expression from the inactive X allele varies from a few percent of that from the active allele to near equal expression. While most genes have a stable inactivation pattern, a subset of genes exhibit tissue-specific differences in escape from X inactivation. Escape genes appear to be protected from the repressive chromatin modifications associated with X inactivation. Differences in the identity and distribution of escape genes between species and tissues suggest a role for these genes in the evolution of sex differences in specific phenotypes. The higher expression of escape genes in females than in males implies that they may have female-specific roles and may be responsible for some of the phenotypes observed in X aneuploidy.

  8. Escape statistics for parameter sweeps through bifurcations.

    Science.gov (United States)

    Miller, Nicholas J; Shaw, Steven W

    2012-04-01

    We consider the dynamics of systems undergoing parameter sweeps through bifurcation points in the presence of noise. Of interest here are local codimension-one bifurcations that result in large excursions away from an operating point that is transitioning from stable to unstable during the sweep, since information about these "escape events" can be used for system identification, sensing, and other applications. The analysis is based on stochastic normal forms for the dynamic saddle-node and subcritical pitchfork bifurcations with a time-varying bifurcation parameter and additive noise. The results include formulation and numerical solution for the distribution of escape events in the general case and analytical approximations for delayed bifurcations for which escape occurs well beyond the corresponding quasistatic bifurcation points. These bifurcations result in amplitude jumps encountered during parameter sweeps and are particularly relevant to nano- and microelectromechanical systems, for which noise can play a significant role.

  9. Thermal escape from extrasolar giant planets.

    Science.gov (United States)

    Koskinen, Tommi T; Lavvas, Panayotis; Harris, Matthew J; Yelle, Roger V

    2014-04-28

    The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres.

  10. Cosmic ray escape from supernova remnants

    CERN Document Server

    Gabici, Stefano

    2011-01-01

    Galactic cosmic rays are believed to be accelerated at supernova remnants via diffusive shock acceleration. Though this mechanism gives fairly robust predictions for the spectrum of particles accelerated at the shock, the spectrum of the cosmic rays which are eventually injected in the interstellar medium is more uncertain and depends on the details of the process of particle escape from the shock. Knowing the spectral shape of these escaping particles is of crucial importance in order to assess the validity of the supernova remnant paradigm for cosmic ray origin. Moreover, after escaping from a supernova remnant, cosmic rays interact with the surrounding ambient gas and produce gamma rays in the vicinity of the remnant itself. The detection of this radiation can be used as an indirect proof of the fact that the supernova remnant was indeed accelerating cosmic rays in the past.

  11. Bacillus anthracis factors for phagosomal escape.

    Science.gov (United States)

    Tonello, Fiorella; Zornetta, Irene

    2012-07-01

    The mechanism of phagosome escape by intracellular pathogens is an important step in the infectious cycle. During the establishment of anthrax, Bacillus anthracis undergoes a transient intracellular phase in which spores are engulfed by local phagocytes. Spores germinate inside phagosomes and grow to vegetative bacilli, which emerge from their resident intracellular compartments, replicate and eventually exit from the plasma membrane. During germination, B. anthracis secretes multiple factors that can help its resistance to the phagocytes. Here the possible role of B. anthracis toxins, phospholipases, antioxidant enzymes and capsules in the phagosomal escape and survival, is analyzed and compared with that of factors of other microbial pathogens involved in the same type of process.

  12. Explosive Fracturing of an F-16 Canopy for Through-Canopy Crew Egress

    Science.gov (United States)

    Bement, Laurence J.

    2000-01-01

    Through-canopy crew egress, such as in the Harrier (AV-8B) aircraft, expands escape envelopes by reducing seat ejection delays in waiting for canopy jettison. Adverse aircraft attitude and reduced forward flight speed can further increase the times for canopy jettison. However, the advent of heavy, high-strength polycarbonate canopies for bird-strike resistance has not only increased jettison times, but has made seat penetration impossible. The goal of the effort described in this paper was to demonstrate a method of explosively fracturing the F-16 polycarbonate canopy to allow through-canopy crew ejection. The objectives of this effort were to: 1. Mount the explosive materials on the exterior of the canopy within the mold line, 2. Minimize visual obstructions, 3. Minimize internal debris on explosive activation, 4. Operate within less than 10 ms, 5. Maintain the shape of the canopy after functioning to prevent major pieces from entering the cockpit, and 6. Minimize the resistance of the canopy to seat penetration. All goals and objectives were met in a full-scale test demonstration. In addition to expanding crew escape envelopes, this canopy fracture approach offers the potential for reducing system complexity, weight and cost, while increasing overall reliability, compared to current canopy jettison approaches. To comply with International Traffic in Arms Regulations (ITAR) and permit public disclosure, this document addresses only the principles of explosive fracturing of the F-16 canopy materials and the end result. ITAR regulations restrict information on improving the performance of weapon systems. Therefore, details on the explosive loads and final assembly of this canopy fracture approach, necessary to assure functional performance, are not included.

  13. Continuous Reliability Enhancement for Wind (CREW) database :

    Energy Technology Data Exchange (ETDEWEB)

    Hines, Valerie Ann-Peters; Ogilvie, Alistair B.; Bond, Cody R.

    2013-09-01

    To benchmark the current U.S. wind turbine fleet reliability performance and identify the major contributors to component-level failures and other downtime events, the Department of Energy funded the development of the Continuous Reliability Enhancement for Wind (CREW) database by Sandia National Laboratories. This report is the third annual Wind Plant Reliability Benchmark, to publically report on CREW findings for the wind industry. The CREW database uses both high resolution Supervisory Control and Data Acquisition (SCADA) data from operating plants and Strategic Power Systems ORAPWindª (Operational Reliability Analysis Program for Wind) data, which consist of downtime and reserve event records and daily summaries of various time categories for each turbine. Together, these data are used as inputs into CREWs reliability modeling. The results presented here include: the primary CREW Benchmark statistics (operational availability, utilization, capacity factor, mean time between events, and mean downtime); time accounting from an availability perspective; time accounting in terms of the combination of wind speed and generation levels; power curve analysis; and top system and component contributors to unavailability.

  14. Implications of Advanced Technologies for Air and Spacecraft Escape

    Science.gov (United States)

    1990-02-01

    Participation in AGARD activities is by invitation only and is normally limited to citizens of the NATO nations. "The content of this publication has been...J.A.Winship, CAF AGARD/’NATO 7, rue Ancelle 92200 Neuilly sur Seine France iv Best Available Copy CONTENTS PREFACE Pg PAM~ AND MEFI1NG OFFICIALS...toldrance cardio- vasculaire et roopirataire ni ia taldrence au:: of Lots vestibulaires does rotations no sont oxcellentes shez lea sojets non entrainda. On

  15. Martian Atmospheric and Ionospheric plasma Escape

    Science.gov (United States)

    Lundin, Rickard

    2016-04-01

    Solar forcing is responsible for the heating, ionization, photochemistry, and erosion processes in the upper atmosphere throughout the lifetime of the terrestrial planets. Of the four terrestrial planets, the Earth is the only one with a fully developed biosphere, while our kin Venus and Mars have evolved into arid inhabitable planets. As for Mars, there are ample evidences for an early Noachian, water rich period on Mars. The question is, what made Mars evolve so differently compared to the Earth? Various hydrosphere and atmospheric evolution scenarios for Mars have been forwarded based on surface morphology, chemical composition, simulations, semi-empiric (in-situ data) models, and the long-term evolution of the Sun. Progress has been made, but the case is still open regarding the changes that led to the present arid surface and tenuous atmosphere at Mars. This presentation addresses the long-term variability of the Sun, the solar forcing impact on the Martian atmosphere, and its interaction with the space environment - an electromagnetic wave and particle interaction with the upper atmosphere that has implications for its photochemistry, composition, and energization that governs thermal and non-thermal escape. Non-thermal escape implies an electromagnetic upward energization of planetary ions and molecules to velocities above escape velocity, a process governed by a combination of solar EUV radiation (ionization), and energy and momentum transfer by the solar wind. The ion escape issue dates back to the early Soviet and US-missions to Mars, but the first more accurate estimates of escape rates came with the Phobos-2 mission in 1989. Better-quality ion composition measurement results of atmospheric/ionospheric ion escape from Mars, obtained from ESA Mars Express (MEX) instruments, have improved our understanding of the ion escape mechanism. With the NASA MAVEN spacecraft orbiting Mars since Sept. 2014, dual in-situ measurement with plasma instruments are now

  16. Do the visual conditions at the point of escape affect European sea bass escape behavior?

    Directory of Open Access Journals (Sweden)

    I.E. PAPADAKIS

    2013-04-01

    Full Text Available European sea bass (Dicentrarchus labrax, an important species for the Mediterranean aquaculture industry, has been reported to escape from sea cage installations. Fish escapes are caused mainly by operational and technical failures that eventually result into a creation of a tear. Escapees may interact with wild stocks through interbreeding, transfer of pathogens and competition for food. The aim of this study was to examine at which extent the presence of a visible obstacle close to a tear on the net have an influence on sea bass propensity to escape. Fish were initially confined into small sea cages, with a tear at one side. The escape behavior was tested under experimental conditions. It is clearly demonstrated that sea bass was able to locate a tear on the net pen, immediately after its appearance. Crossings occurred in all cages, in singles or in a series of up to seven individuals. The presence of an obstacle close to the net tear altered the escape behavior of D. labrax resulting in a delay that eventually reduced the escape rate. Concluding, it is highly recommended that sea bass cages should be kept internally the culture array. Furthermore, the placement of artificial obstacles close to the sea cages could be an efficient practice that mitigates the escape risk after severe environmental conditions.

  17. Space shuttle crew training at CERN

    CERN Multimedia

    Paola Catapano

    From 13 to 16 October, the crew of NASA Space Shuttle mission STS-134 came to CERN for a special physics training programme. Invited here by Samuel Ting, they will deliver the Alpha Magnetic Spectrometer (AMS) detector to the International Space Station (ISS).   The STS134 crew in the Lodge at the Aiguille du Midi wearing CERN fleeces. From left to right: Captain Mark Kelly, US Navy; Pilot Gregory Johnson, USAF ret.; Mission Specialist Andrew Feustel; Mission Specialist Mike Fincke, USAF, Mission Specialist Gregory Chamitoff and Mission Specialist Roberto Vittori, ESA and Italian Air Force. Headed by Commander Mark Kelly, a US Navy captain, the crew included pilot Gregory Johnson, a US Air Force (USAF) colonel, and mission specialists Mike Fincke (also a USAF Colonel), Andrew Feustel, and Gregory Chamitoff of NASA, as well as Colonel Roberto Vittori of the European Space Agency (ESA). Two flight directors, Gary Horlache and Derek Hassmann of NASA, and the engineer responsible for the Ext...

  18. Crew Exploration Vehicle (CEV) (Orion) Occupant Protection

    Science.gov (United States)

    Currie-Gregg, Nancy J.; Gernhardt, Michael L.; Lawrence, Charles; Somers, Jeffrey T.

    2016-01-01

    Dr. Nancy J. Currie, of the NASA Engineering and Safety Center (NESC), Chief Engineer at Johnson Space Center (JSC), requested an assessment of the Crew Exploration Vehicle (CEV) occupant protection as a result of issues identified by the Constellation Program and Orion Project. The NESC, in collaboration with the Human Research Program (HRP), investigated new methods associated with occupant protection for the Crew Exploration Vehicle (CEV), known as Orion. The primary objective of this assessment was to investigate new methods associated with occupant protection for the CEV, known as Orion, that would ensure the design provided minimal risk to the crew during nominal and contingency landings in an acceptable set of environmental and spacecraft failure conditions. This documents contains the outcome of the NESC assessment. NASA/TM-2013-217380, "Application of the Brinkley Dynamic Response Criterion to Spacecraft Transient Dynamic Events." supercedes this document.

  19. Nociception and escape behavior in planarians

    Science.gov (United States)

    Schoetz Collins, Eva-Maria

    2015-03-01

    Planarians are famous and widely studied for their regenerative capabilities. When a moving planarian is cut through the middle, the resulting head and tail pieces instantaneously retract and exhibit a characteristic escape response that differs from normal locomotion. In asexual animals, a similar reaction is observed when the planarian undergoes fission, suggesting that reproduction through self-tearing is a rather traumatic event for the animal. Using a multiscale approach, we unravel the dynamics, mechanics, and functional aspects of the planarian escape response. This musculature-driven gait was found to be a dominating response that supersedes the urge to feed or reproduce and quantitatively differs from other modes of planarian locomotion (gliding, peristalsis). We show that this escape gait constitutes the animal's pain response mediated by TRP like receptors and the neurotransmitter histamine, and that it can be induced through adverse thermal, mechanical, electrical or chemical stimuli. Ultimately, we will examine the neuronal subpopulations involved in mediating escape reflexes in planarians and how they are functionally restored during regeneration, thereby gaining mechanistic insight into the neuronal circuits required for specific behaviors. Supported by BWF CASI and Sloan Foundation.

  20. Net escapement of Antartic krill in trawls

    DEFF Research Database (Denmark)

    Krafft, B.A.; Krag, Ludvig Ahm; Herrmann, Bent;

    This document describes the aims and methodology of a three year project (commenced in 2012) entitled Net Escapement of Antarctic krill in Trawls (NEAT). The study will include a morphology based mathematical modeling (FISHSELECT) of different sex and maturity groups of Antarctic krill (Euphausia...

  1. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    Science.gov (United States)

    Delcourt, Dominique; Seki, K.; Terada, N.; Moore, Thomas E.

    2012-01-01

    We investigate the transport of ions in the low-altitude magnetosphere magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of the E B drift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low-energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low-energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, the E B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.

  2. STS-129 shuttle crew visits Stennis

    Science.gov (United States)

    2010-01-01

    Members of the STS-129 space shuttle crew visited NASA's John C. Stennis Space Center on Jan. 19 to share details of their November visit to the International Space Station. During their 11-day mission aboard shuttle Atlantis, crew members delivered equipment, supplies and spare parts to the ISS. Following their mission report, astronauts visited with Stennis employees during a brief reception. Astronauts visiting Stennis were Pilot Barry Wilmore, Mission Specialist Randy Bresnik, Commander Charles Hobaugh and Mission Specialists Mike Foreman and Robert Satcher.

  3. Temporal and ontogenetic variation in the escape response of Ameiva festiva (Squamata, Teiidae

    Directory of Open Access Journals (Sweden)

    Lattanzio

    2014-08-01

    Full Text Available Several factors have been shown to affect lizard escape behavior (flight initiation distance or FID, the distance between predator and prey when the prey initiates escape. Patterns of daily activity, such as foraging or movement behavior, vary with respect to time of day, supporting that escape responses may vary temporally as well. However, there remains scant information regarding the effects of time of day on FID. During peak activity, FID may decrease due to increased cost of giving up resources (e.g., prey or potential mates. An alternative hypothesis is that FID may increase because lizard activity in general may serve to alert a predator in advance of its approach. A lizard in this scenario may be favored to flee sooner rather than later. Moreover, juvenile and adult lizards of multiple species may differ in behavioral, ecological, and morphological traits that could influence escape decisions. I tested the effects of time of day (in 30-min intervals and age (juvenile or adult on the FID of a tropical whiptail lizard, Ameiva festiva in Costa Rica. I found that A. festiva escape responses varied with time of day such that in general, their FID decreased throughout the day. In addition, I observed a peak in FID from mid to late-morning that matches published estimates of peak activity times for A. festiva. Overall, juvenile A. festiva initiated an escape response sooner than adults, which may be related to differences in perceived risk associated with differences in size and predator experience between the two age groups. I conclude that escape responses may be contingent on both the activity level of the animal at the time of approach and its age.

  4. Crew Transportation Technical Standards and Design Evaluation Criteria

    Science.gov (United States)

    Lueders, Kathryn L.; Thomas, Rayelle E. (Compiler)

    2015-01-01

    Crew Transportation Technical Standards and Design Evaluation Criteria contains descriptions of technical, safety, and crew health medical processes and specifications, and the criteria which will be used to evaluate the acceptability of the Commercial Providers' proposed processes and specifications.

  5. Multifunctional Coating for Crew Cabin Surfaces and Fabrics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's crewed spacecrafts require routine cleaning of particulate, moisture, organic, and salt contaminants on the crew cabin surfaces and fabrics. Self-cleaning...

  6. Cosmic radiation exposure at aircraft crew workplaces

    Energy Technology Data Exchange (ETDEWEB)

    Latocha, M.; Beck, P.; Rollet, S. [ARC Seibersdorf Research, Seibersdorf (Austria); Latocha, M. [Institute of Nuclear Physics Polish Academy of Sciences, Krakow (Poland)

    2006-07-01

    E.U.R.A.D.O.S. working group W.G.5. on air crew dosimetry coordinated research of some 24 international institutes to exchange experimental data and results of calculations of the radiation exposure in aircraft altitudes due to cosmic radiation. The purpose was to provide a data-set for all European Union Member States for the assessment of individual doses, the validity of different approaches, and to provide an input to technical recommendations by the Article 31 group of experts and the European Commission. The results of this work have been recently published and are available for the international community. The radiation protection quantity of interest is effective dose, E (ISO), but the comparison of measurement results and the results of calculations, is done in terms of the operational quantity ambient dose equivalent, H{sup *}(10). This paper gives an overview of the E.U.R.A.D.O.S. Aircraft Crew In-Flight Database which was implemented under the responsibility of A.R.C. Seibersdorf research. It discusses calculation models for air crew dose assessment comparing them with measurements contained in this database. Further it presents current developments using updated information of galactic cosmic radiation proton spectra and new results of the recently finalized European research project D.O.S.M.A.X. on dosimetry of aircraft crew at solar maximum. (authors)

  7. COMMUNICATION PROBLEMS IN A MIXED CREW ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    CARMEN ASTRATINEI

    2016-06-01

    Full Text Available Shipping has become a highly international and multicultural industry due to a globalised labour market of seafarers. About two thirds of the world`s merchant fleets, are manned by a mixed crew, which may include two to three different nationalities. The common language used on board ship is English. So the crewmembers must have a good command of this language. 80% of all maritime accidents are, according to incident reports, caused by human error i.e. negligence, fatigue, incompetence or communication breakdown. Another factor that may affect the safety of crew and cargo is the cultural differences within the mixed nationality crews which, if not appeased in time, may lead to very serious conflicts. This paper proposes to analyse some characteristics of the Asian culture and traditions and suggest some ways of improving the professional relationship among multinational crew members by making them aware of their shipmates identities. A questionnaire, which we intend to use as a research tool, will be provided and explained.

  8. Integrated and Dynamic Vehicle and Crew Scheduling

    NARCIS (Netherlands)

    D. Huisman (Dennis)

    2004-01-01

    textabstractDue to increased competition in the public transport market and the pressure on governments to cut expenses, increasing attention has been paid to cost reductions in public transportation. Since the main resources used in public transportation are vehicles and crews, producing efficient

  9. 19 CFR 122.45 - Crew list.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Crew list. 122.45 Section 122.45 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for...

  10. 26 CFR 31.3121(o)-1 - Crew leader.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Crew leader. 31.3121(o)-1 Section 31.3121(o)-1... Contributions Act (Chapter 21, Internal Revenue Code of 1954) General Provisions § 31.3121(o)-1 Crew leader. The term “crew leader” means an individual who furnishes individuals to perform agricultural labor...

  11. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Lusby, Richard Martin; Ryan, David M.;

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However...

  12. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Ryan, David M.; Lusby, Richard Martin;

    2010-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However...

  13. Subsequence Generation for the Airline Crew Pairing Problem

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Lusby, Richard Martin; Ryan, David;

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However...

  14. 14 CFR 27.805 - Flight crew emergency exits.

    Science.gov (United States)

    2010-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 27.805 Flight crew emergency exits. (a) For rotorcraft with passenger emergency exits that are not convenient to the flight crew, there must be flight crew emergency exits, on both sides of the rotorcraft...

  15. 14 CFR 29.805 - Flight crew emergency exits.

    Science.gov (United States)

    2010-01-01

    ... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Personnel and Cargo Accommodations § 29.805 Flight crew emergency exits. (a) For rotorcraft with passenger emergency exits that are... rotorcraft or as a top hatch, in the flight crew area. (b) Each flight crew emergency exit must be...

  16. Solving the Airline Crew Pairing Problem using Subsequence Generation

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Ryan, David; Lusby, Richard Martin;

    2009-01-01

    Good and fast solutions to the airline crew pairing problem are highly interesting for the airline industry, as crew costs are the biggest expenditure after fuel for an airline. The crew pairing problem is typically modelled as a set partitioning problem and solved by column generation. However...

  17. 14 CFR 121.385 - Composition of flight crew.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Composition of flight crew. 121.385 Section... Composition of flight crew. (a) No certificate holder may operate an airplane with less than the minimum flight crew in the airworthiness certificate or the airplane Flight Manual approved for that...

  18. Latino High School Students' Perceptions of Gangs and Crews

    Science.gov (United States)

    Lopez, Edward M.; Wishard, Alison; Gallimore, Ronald; Rivera, Wendy

    2006-01-01

    Controversies around definitions and perceptions of gangs are heightened by the scarcity of research on crews. In an open-ended interview, 77 Latino 10th graders from a random longitudinal sample provided information about gangs and crews. Although less than 10% reported having been in gangs or crews, 84% reported having personal contact with…

  19. The escape problem for mortal walkers

    CERN Document Server

    Grebenkov, D S

    2016-01-01

    We introduce and investigate the escape problem for random walkers that may eventually die, decay, bleach, or lose activity during their diffusion towards an escape or reactive region on the boundary of a confining domain. In the case of a first-order kinetics (i.e., exponentially distributed lifetimes), we study the effect of the associated death rate onto the survival probability, the exit probability, and the mean first passage time. We derive the upper and lower bounds and some approximations for these quantities. We reveal three asymptotic regimes of small, intermediate and large death rates. General estimates and asymptotics are compared to several explicit solutions for simple domains, and to numerical simulations. These results allow one to account for stochastic photobleaching of fluorescent tracers in bio-imaging, degradation of mRNA molecules in genetic translation mechanisms, or high mortality rates of spermatozoa in the fertilization process. This is also a mathematical ground for optimizing stor...

  20. Escape and Stand of the Pluto Atmosphere

    Institute of Scientific and Technical Information of China (English)

    GAO Chong-Yi

    2002-01-01

    Molar mass μmin of the lightest gas, which will exist "forever" in the atmosphere at the planet surface,can be evaluated by Jeans rule. The μmin of Pluto is 17.3 g@ mol-1. It is evident that both N2 and CO can be major atmospheric composition at the Pluto surface, and will exist "forever". CH4 can only be escaping slowly from Pluto atmosphere, and still holds quite a proportion in current Pluto atmosphere. However, it will not escape from Titan (or Jupiter, Saturn) atmosphere largely, and will exist "forever". Given the quantitylevelof partial pressure of CH4 in Pluto and Titan (or Jupiter, Saturn) original atmosphere is the same, it will be clear that the current partial pressure of CH4 in Pluto surface atmosphere is 10-3 Pa.

  1. Crew Scheduling Considering both Crew Duty Time Difference and Cost on Urban Rail System

    Directory of Open Access Journals (Sweden)

    Wenliang Zhou

    2016-10-01

    Full Text Available Urban rail crew scheduling problem is to allocate train services to crews based on a given train timetable while satisfying all the operational and contractual requirements. In this paper, we present a new mathematical programming model with the aim of minimizing both the related costs of crew duty and the variance of duty time spreads. In addition to iincorporating the commonly encountered crew scheduling constraints, it also takes into consideration the constraint of arranging crews having a meal in the specific meal period of one day rather than after a minimum continual service time. The proposed model is solved by an ant colony algorithm which is built based on the construction of ant travel network and the design of ant travel path choosing strategy. The performances of the model and the algorithm are evaluated by conducting case study on Changsha urban rail. The results indicate that the proposed method can obtain a satisfactory crew schedule for urban rails with a relatively small computational time.

  2. Effects of submarine escape training on the pulmonary function and carbon dioxide retention in the escape

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui-yong; WANG Wen-bo; FANG Yi-qun; XU Ji; XU Lin-jun

    2011-01-01

    Objective Fast buoyancy ascent escape used in submarine escape is the most probable choice of survival in case of a submarine accident.Rate of success for escape depends very much on the extent of training,in spite of the fact that rapid compression and decompression pose great challenges to the human body in terms of enormous stresses.To minimize stresses experienced during sub escape training has always been a research subject for us.Lungs are susceptible to rapid change in pressure during escape.Dynamic pulmonary function and the end-tidal PCO2 ( PETCO2 ) might be the best indicator for its effect on the pulmonary function of the submarine escapee.Methods Five male navy divers received submarine escape trainings,at different depths from 3-60 m.They were compressed at different rates (with pressure doubled every 20 s or 30 s),in the simulated submarine escape tower located in the Naval Medical Research Institute.The gas of end-expiration was collected immediately after escape,respiratory rate (RR) and dynamic pulmonary function were closely monitored,and PETCO2 was determined with the mass spectrometer.Results Experimental results showed that forced expiratory volume in 1 second (FEV1.0) tended to increase with increasing depth,and that it increased significantly at 50 m and 60 m,when compared with the basic data (P < 0.05 ),and it was coupled with a decrease in forced expiratory flow at 25 % ( FEF25% ),indicating that it had certain effect on the function of small airways.PETCO2 and RR all elevated markedly following escapes.No significant differences could be seen in RR following escapes at various depths.PETCO2 and depth ( r =0.387,P < 0.01 ) were positively correlated with compression rate ( r =0.459,P < 0.01 ) and RR ( r =0.467,P < 0.01 ).CO2 retention might be attributed to pulmonary ventilation disorder induced by rapid changes in pressure.PETCO2 was within normal range,following escapes at various depths,suggesting that increased RR might be

  3. Xenon Fractionation and Archean Hydrogen Escape

    Science.gov (United States)

    Zahnle, K. J.

    2015-01-01

    Xenon is the heaviest gas found in significant quantities in natural planetary atmospheres. It would seem the least likely to escape. Yet there is more evidence for xenon escape from Earth than for any element other than helium and perhaps neon. The most straightforward evidence is that most of the radiogenic Xe from the decay of (129)I (half-life 15.7 Myr) and (244)Pu (half-life 81 Myr) that is Earth's birthright is missing. The missing xenon is often attributed to the impact erosion of early atmospheres of Earth and its ancestors. It is obvious that if most of the radiogenic xenon were driven off by impacts, most of the rest of the atmophiles fared the same fate. The other line of evidence is in the nonradiogenic isotopes of xenon and its silent partner, krypton. Atmospheric xenon is strongly mass fractionated (at about 4% per amu) compared to any known solar system source (Figure 1). This is in stark contrast to krypton, which may not be fractionated at all: atmospheric Kr is slightly heavier than solar Kr (at about 0.5% per amu), but it is the same as in carbonaceous chondrites. Nonradiogenic xenon is also under abundant relative to krypton (the so-called "missing xenon" problem). Together these observations imply that xenon has been subject to fractionating escape and krypton not.

  4. 19 CFR 122.75b - Electronic manifest requirement for crew members and non-crew members onboard commercial aircraft...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Electronic manifest requirement for crew members... THE TREASURY AIR COMMERCE REGULATIONS Documents Required for Clearance and Permission To Depart; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members Onboard...

  5. 19 CFR 122.49b - Electronic manifest requirement for crew members and non-crew members onboard commercial aircraft...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Electronic manifest requirement for crew members... HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members Onboard...

  6. A NASA Perspective on Maintenance Activities and Maintenance Crews

    Science.gov (United States)

    Barth Tim

    2007-01-01

    Proactive consideration of ground crew factors enhances the designs of space vehicles and vehicle safety by: (1) Reducing the risk of undetected ground crew errors and collateral damage that compromise vehicle reliability and flight safety (2) Ensuring compatibility of specific vehicle to ground system interfaces (3) Optimizing ground systems. During ground processing and launch operations, public safety, flight crew safety, ground crew safety, and the safety of high-value spacecraft are inter-related. For extended Exploration missions, surface crews perform functions that merge traditional flight and ground operations.

  7. Risks incurred by hydrogen escaping from containers and conduits

    Energy Technology Data Exchange (ETDEWEB)

    Swain, M.R.; Grilliot, E.S. [Univ. of Miami, Coral Gables, FL (United States); Swain, M.N. [Analytical Technologies, Inc., Miami, FL (United States)

    1998-08-01

    This paper is a discussion of a method for hydrogen leak classification. Leaks are classified as; gas escapes into enclosed spaces, gas escapes into partially enclosed spaces (vented), and gas escapes into unenclosed spaces. Each of the three enclosure classifications is further divided into two subclasses; total volume of hydrogen escaped and flow rate of escaping hydrogen. A method to aid in risk assessment determination in partially enclosed spaces is proposed and verified for several enclosure geometries. Examples are discussed for additional enclosure geometries.

  8. Escape from attracting sets in randomly perturbed systems.

    Science.gov (United States)

    Rodrigues, Christian S; Grebogi, Celso; de Moura, Alessandro P S

    2010-10-01

    The dynamics of escape from an attractive state due to random perturbations is of central interest to many areas in science. Previous studies of escape in chaotic systems have rather focused on the case of unbounded noise, usually assumed to have Gaussian distribution. In this paper, we address the problem of escape induced by bounded noise. We show that the dynamics of escape from an attractor's basin is equivalent to that of a closed system with an appropriately chosen "hole." Using this equivalence, we show that there is a minimum noise amplitude above which escape takes place, and we derive analytical expressions for the scaling of the escape rate with noise amplitude near the escape transition. We verify our analytical predictions through numerical simulations of two well-known two-dimensional maps with noise.

  9. The cost of the sword: escape performance in male swordtails.

    Directory of Open Access Journals (Sweden)

    Alex Baumgartner

    Full Text Available The handicap theory of sexual selection posits that male display traits that are favored in mate choice come at a significant cost to performance. We tested one facet of this hypothesis in the green swordtail (Xiphophorus helleri. In this species, the lower ray of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase drag and thus compromise a male's ability to swim effectively. We tested escape performance in this species by eliciting C-start escape responses, an instinctive escape behavior, in males with various sword lengths. We then removed males' swords and retested escape performance. We found no relationship between escape performance and sword length and no effect of sword removal on escape performance. While having a large sword may attract a predator's attention, our results suggest that sword size does not compromise a male's escape performance.

  10. Helicopter crew/passenger vibration sensitivity -

    Science.gov (United States)

    Gabel, R.; Reed, D. A.

    1972-01-01

    Helicopter crew and passenger vibration sensitivity are presented. Pilot subjective ratings are established for discrete frequencies and the impact of combinations of harmonic frequencies is examined. A passenger long term comfort level and a short term limit are defined for discrete frequencies and compared with pilot ratings. The results show reasonable agreement between pilot and passenger. Subjective comfort levels obtained for mixed frequency environments clearly demonstrate the need for a multi-frequency criterion.

  11. The Home Care Crew Scheduling Problem

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Justesen, Tor

    In the Home Care Crew Scheduling Problem (HCCSP) a staff of caretakers has to be assigned a number of visits, such that the total number of assigned visits is maximised. The visits have different locations and positions in time, and travelling time and time windows must be respected. The challenge...... clustering of the visits based on the problem structure. The algorithm is tested on real-life problem instances and we obtain solutions that are better than current practice in all cases....

  12. Crew goal setting for security control

    OpenAIRE

    Wetter, Olive Emil; Hofer, Franziska; Jonas, Klaus

    2013-01-01

    This study investigated the effectiveness, efficiency, and robustness of simple goal setting in airport security control. As outcome, crew performance in terms of productivity (Experiment 1, field setting) was studied. Furthermore, the moderating role of negative and positive priming due to a previous task on the impact of goals (Experiment 2, laboratory setting) was analyzed. This research builds a bridge from goal setting theory to practice and prepares the grounds for its application in se...

  13. Arduino adventures escape from Gemini station

    CERN Document Server

    Kelly, James Floyd

    2013-01-01

    Arduino Adventures: Escape from Gemini Station provides a fun introduction to the Arduino microcontroller by putting you (the reader) into the action of a science fiction adventure story.  You'll find yourself following along as Cade and Elle explore Gemini Station-an orbiting museum dedicated to preserving and sharing technology throughout the centuries. Trouble ensues. The station is evacuated, including Cade and Elle's class that was visiting the station on a field trip. Cade and Elle don't make it aboard their shuttle and are trapped on the station along with a friendly artificial intellig

  14. Evolutionary escape from the prisoner's dilemma.

    Science.gov (United States)

    Worden, Lee; Levin, Simon A

    2007-04-07

    The classic prisoner's dilemma model of game theory is modified by introducing occasional variations on the options available to players. Mutation and selection of game options reliably change the game matrix, gradually, from a prisoner's dilemma game into a byproduct mutualism one, in which cooperation is stable, and "temptation to defect" is replaced by temptation to cooperate. This result suggests that when there are many different potential ways of interacting, exploring those possibilities may make escape from prisoner's dilemmas a common outcome in the world. A consequence is that persistent prisoner's dilemma structures may be less common than one might otherwise expect.

  15. Fast escaping points of entire functions

    CERN Document Server

    Rippon, P J

    2010-01-01

    Let $f$ be a transcendental entire function and let $A(f)$ denote the set of points that escape to infinity `as fast as possible' under iteration. By writing $A(f)$ as a countable union of closed sets, called `levels' of $A(f)$, we obtain a new understanding of the structure of this set. For example, we show that if $U$ is a Fatou component in $A(f)$, then $\\partial U\\subset A(f)$ and this leads to significant new results and considerable improvements to existing results about $A(f)$. In particular, we study functions for which $A(f)$, and each of its levels, has the structure of an `infinite spider's web'. We show that there are many such functions and that they have a number of strong dynamical properties. This new structure provides an unexpected connection between a conjecture of Baker concerning the components of the Fatou set and a conjecture of Eremenko concerning the components of the escaping set.

  16. Molecular Dications in Planetary Atmospheric Escape

    Directory of Open Access Journals (Sweden)

    Stefano Falcinelli

    2016-08-01

    Full Text Available Fundamental properties of multiply charged molecular ions, such as energetics, structure, stability, lifetime and fragmentation dynamics, are relevant to understand and model the behavior of gaseous plasmas as well as ionosphere and astrophysical environments. Experimental determinations of the Kinetic Energy Released (KER for ions originating from dissociations reactions, induced by Coulomb explosion of doubly charged molecular ions (molecular dications produced by double photoionization of CO2, N2O and C2H2 molecules of interest in planetary atmospheres, are reported. The KER measurement as a function of the ultraviolet (UV photon energy in the range of 28–65 eV was extracted from the electron-ion-ion coincidence spectra obtained by using tunable synchrotron radiation coupled with ion imaging techniques at the ELETTRA Synchrotron Light Laboratory Trieste, Italy. These experiments, coupled with a computational analysis based on a Monte Carlo trajectory simulation, allow assessing the probability of escape for simple ionic species in the upper atmosphere of Mars, Venus and Titan. The measured KER in the case of H+, C+, CH+, CH2+, N+, O+, CO+, N2+ and NO+ fragment ions range between 1.0 and 5.5 eV, being large enough to allow these ionic species to participate in the atmospheric escape from such planets into space. In the case of Mars, we suggest a possible explanation for the observed behavior of the O+ and CO22+ ion density profiles.

  17. Escape of water molecular from Carbon Nanotubes

    Science.gov (United States)

    Li, Jiaxi; Li, Wenfeng; Zhang, Jianwei

    2014-03-01

    Understanding and controlling the transport of water molecules through nanopores have attracted great interest due to potential applications for designing novel nanofluidic devices, machines and sensors. In this work, we theoretically investigate the effects of an external nonuniform electric field on the escape of water molecules through single-walled carbon nanotubes (SWNTs) by using of molecular dynamics (MD) simulations. When polar water molecules are placed in the gradient electric field, the electric force is experienced that can drive the water molecules. Molecular dynamics simulations show that the escape probability of water obeys the Boltzmann distribution. Our results show that energy barrier delta E is independent of temperature which indicates that it is a single-barrier system. From the MD results statistics, the key parameters could be determined such that the relationship between energy barrier delta E and diameter of SWNTs and nozzle distance of the charge r would be revealed that could deepen our current theoretical understanding on transport of water molecular inside SWNTs with the nonuniform electric field.

  18. Uremic escape of renal allograft rejection

    Energy Technology Data Exchange (ETDEWEB)

    van Schilfgaarde, R. (Rijksuniversiteit Leiden (Netherlands). Academisch Ziekenhuis); van Breda Vriesman, P.J.C. (Rijksuniversiteit Limburg Maastricht (Netherlands). Dept. of Immunopathology)

    1981-10-01

    It is demonstrated in rats that, in the presence of early postoperative severe but transient uremia, the survival of first set Brown-Norway (BN) renal allografts in Lewis (LEW) recipients is at least three times prolonged when compared to non-uremic controls. This phenomenon is called 'uremic escape of renal allograft rejection'. By means of lethal X-irradiation of donors of BN kidneys transplanted into transiently uremic and non-uremic LEW recipients, the presence of passenger lymphocyte immunocompetence is demonstrated to be obilgatory for this phenomenon to occur. As a result of mobile passenger lymphocyte immunocompetence, a graft-versus-host (GVH) reaction is elicited in the spleens of LEW recipients of BN kidneys which amplifies the host response. The splenomegaly observed in LEW recipients of BN kidneys is caused not only by this GVH reaction, which is shown to be exquisitely sensitive to even mild uremia. It is also contributed to by a proliferative response of the host against the graft (which latter response is equated with an in vivo equivalent of a unilateral mixed lymphocyte reaction (MLR)), since the reduction in spleen weights caused by abrogation of mobile passenger lymphocyte immunocompetence brought about by lethal donor X-irradiation is increased significantly by early postoperative severe but transient uremia. It is concluded that in uremic escape of renal allograft rejection both reactions are suppressed by uremia during the early post-operative period.

  19. Escape from viscosity : the kinematics and hydrodynamics of copepod foraging and escape swimming

    NARCIS (Netherlands)

    van Duren, LA; Videler, JJ

    2003-01-01

    Feeding and escape swimming in adult females of the calanoid copepod. Temora lopgicornis Muller were investigated and compared. Swimming velocities were calculated using a 3-D filming setup., Foraging velocities ranged between 2 and 6 min s(-1), while maximum velocities of up to 80 mm s(-1) were rea

  20. Strong purifying selection at genes escaping X chromosome inactivation.

    Science.gov (United States)

    Park, Chungoo; Carrel, Laura; Makova, Kateryna D

    2010-11-01

    To achieve dosage balance of X-linked genes between mammalian males and females, one female X chromosome becomes inactivated. However, approximately 15% of genes on this inactivated chromosome escape X chromosome inactivation (XCI). Here, using a chromosome-wide analysis of primate X-linked orthologs, we test a hypothesis that such genes evolve under a unique selective pressure. We find that escape genes are subject to stronger purifying selection than inactivated genes and that positive selection does not significantly affect the evolution of these genes. The strength of selection does not differ between escape genes with similar versus different expression levels in males versus females. Intriguingly, escape genes possessing Y homologs evolve under the strongest purifying selection. We also found evidence of stronger conservation in gene expression levels in escape than inactivated genes. We hypothesize that divergence in function and expression between X and Y gametologs is driving such strong purifying selection for escape genes.

  1. High level organizing principles for display of systems fault information for commercial flight crews

    Science.gov (United States)

    Rogers, William H.; Schutte, Paul C.

    1993-01-01

    Advanced fault management aiding concepts for commercial pilots are being developed in a research program at NASA Langley Research Center. One aim of this program is to re-evaluate current design principles for display of fault information to the flight crew: (1) from a cognitive engineering perspective and (2) in light of the availability of new types of information generated by advanced fault management aids. The study described in this paper specifically addresses principles for organizing fault information for display to pilots based on their mental models of fault management.

  2. Cancer incidence among Nordic airline cabin crew.

    Science.gov (United States)

    Pukkala, Eero; Helminen, Mika; Haldorsen, Tor; Hammar, Niklas; Kojo, Katja; Linnersjö, Anette; Rafnsson, Vilhjálmur; Tulinius, Hrafn; Tveten, Ulf; Auvinen, Anssi

    2012-12-15

    Airline cabin crew are occupationally exposed to cosmic radiation and jet lag with potential disruption of circadian rhythms. This study assesses the influence of work-related factors in cancer incidence of cabin crew members. A cohort of 8,507 female and 1,559 male airline cabin attendants from Finland, Iceland, Norway and Sweden was followed for cancer incidence for a mean follow-up time of 23.6 years through the national cancer registries. Standardized incidence ratios (SIRs) were defined as ratios of observed and expected numbers of cases. A case-control study nested in the cohort (excluding Norway) was conducted to assess the relation between the estimated cumulative cosmic radiation dose and cumulative number of flights crossing six time zones (indicator of circadian disruption) and cancer risk. Analysis of breast cancer was adjusted for parity and age at first live birth. Among female cabin crew, a significantly increased incidence was observed for breast cancer [SIR 1.50, 95% confidence interval (95% CI) 1.32-1.69], leukemia (1.89, 95% CI 1.03-3.17) and skin melanoma (1.85, 95% CI 1.41-2.38). Among men, significant excesses in skin melanoma (3.00, 95% CI 1.78-4.74), nonmelanoma skin cancer (2.47, 95% CI 1.18-4.53), Kaposi sarcoma (86.0, 95% CI 41.2-158) and alcohol-related cancers (combined SIR 3.12, 95% CI 1.95-4.72) were found. This large study with complete follow-up and comprehensive cancer incidence data shows an increased incidence of several cancers, but according to the case-control analysis, excesses appear not to be related to the cosmic radiation or circadian disruptions from crossing multiple time zones.

  3. Chromosomal aberrations in ISS crew members

    Science.gov (United States)

    Johannes, Christian; Goedecke, Wolfgang; Antonopoulos, Alexandra

    2012-07-01

    High energy radiation is a major risk factor in manned space missions. Astronauts and cosmonauts are exposed to ionising radiations of cosmic and solar origin, while on the Earth's surface people are well protected by the atmosphere and a deflecting magnetic field. There are now data available describing the dose and the quality of ionising radiation on-board of the International Space Station (ISS). Nonetheless, the effect of increased radiation dose on mutation rates of ISS crew members are hard to predict. Therefore, direct measurements of mutation rates are required in order to better estimate the radiation risk for longer duration missions. The analysis of chromosomal aberrations in peripheral blood lymphocytes is a well established method to measure radiation-induced mutations. We present data of chromosome aberration analyses from lymphocyte metaphase spreads of ISS crew members participating in short term (10-14 days) or long term (around 6 months) missions. From each subject we received two blood samples. The first sample was drawn about 10 days before launch and a second one within 3 days after return from flight. From lymphocyte cultures metaphase plates were prepared on glass slides. Giemsa stained and in situ hybridised metaphases were scored for chromosome changes in pre-flight and post-flight blood samples and the mutation rates were compared. Results obtained in chromosomal studies on long-term flight crew members showed pronounced inter-individual differences in the response to elevated radiation levels. Overall slight but significant elevations of typical radiation induced aberrations, i.e., dicentric chromosomes and reciprocal translocations have been observed. Our data indicate no elevation of mutation rates due to short term stays on-board the ISS.

  4. Interplay and escape in three-body scattering.

    Science.gov (United States)

    Shebalin, J. V.; Tippens, A. L.

    1996-05-01

    The problem of three gravitationally interacting bodies, with total energy less than zero, is investigated numerically. After introducing the concepts of `periastron graphs' and `composite binaries', time-of-escape and interplay are precisely defined. These definitions are useful in characterizing the complete scattering process: escape to t=-{infinity}, interplay, and escape to t=+{infinity}. These definitions are also useful for the efficient and automatic termination of a numerical simulation of interplay.

  5. Crew participating in the ALICE TRD beamtests

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Photo 1: Sitting in front of the experimental setup is part of the crew participating in the ALICE TRD beamtests at pion/electron secondary beams at CERN Proton Synchrotron in October 2002. From left to right: Mircea Ciobanu, Andres Sandoval, Vojtech Petracek, Oliver Busch, Chilo Garabatos, Wilrid Ludolphs and Harald Appelshaeuser. photo 2: Two fierce experimental physicists, Chilo Garabatos (left) and Anton Andronic, guarding their most valuable asset: Transition Radiation Detector prototypes for the ALICE experiment. These detectors are tested in electron/pion secondary beams at CERN Proton Synchrotron.

  6. International Space Station Crew Restraint Design

    Science.gov (United States)

    Whitmore, M.; Norris, L.; Holden, K.

    2005-01-01

    With permanent human presence onboard the International Space Station (ISS), crews will be living and working in microgravity, dealing with the challenges of a weightless environment. In addition, the confined nature of the spacecraft environment results in ergonomic challenges such as limited visibility and access to the activity areas, as well as prolonged periods of unnatural postures. Without optimum restraints, crewmembers may be handicapped for performing some of the on-orbit tasks. Currently, many of the tasks on ISS are performed with the crew restrained merely by hooking their arms or toes around handrails to steady themselves. This is adequate for some tasks, but not all. There have been some reports of discomfort/calluses on the top of the toes. In addition, this type of restraint is simply insufficient for tasks that require a large degree of stability. Glovebox design is a good example of a confined workstation concept requiring stability for successful use. They are widely used in industry, university, and government laboratories, as well as in the space environment, and are known to cause postural limitations and visual restrictions. Although there are numerous guidelines pertaining to ventilation, seals, and glove attachment, most of the data have been gathered in a 1-g environment, or are from studies that were conducted prior to the early 1980 s. Little is known about how best to restrain a crewmember using a glovebox in microgravity. In 2004, The Usability Testing and Analysis Facility (UTAF) at the NASA Johnson Space Center completed development/evaluation of several design concepts for crew restraints to meet the various needs outlined above. Restraints were designed for general purpose use, for teleoperation (Robonaut) and for use with the Life Sciences Glovebox. All design efforts followed a human factors engineering design lifecycle, beginning with identification of requirements followed by an iterative prototype/test cycle. Anthropometric

  7. STS-104 Crew Interview: Steve Lindsey

    Science.gov (United States)

    2001-01-01

    STS-104 Commander Steve Lindsey is seen being interviewed. He answers questions about his inspiration to become an astronaut and his career path. He gives details on the mission's goals and significance, its payload (the Joint Airlock and the external gas tanks), and the usefulness of the newly installed Canadian Robotic Arm (installed by STS-100 crew). Lindsey describes his role in the rendezvous, docking, undocking, and flyaround of the Atlantis Orbiter and the International Space Station (ISS) and discusses the mission's planned spacewalks.

  8. Crew coordination concepts: Continental Airlines CRM training

    Science.gov (United States)

    Christian, Darryl; Morgan, Alice

    1987-01-01

    The outline of the crew coordination concepts at Continental airlines is: (1) Present relevant theory: Contained in a pre-work package and in lecture/discussion form during the work course, (2) Discuss case examples: Contained in the pre-work for study and use during the course; and (3) Simulate practice problems: Introduced during the course as the beginning of an ongoing process. These concepts which are designed to address the problem pilots have in understanding the interaction between situations and their own theories of practice are briefly discussed.

  9. APOLLO 13: The Crew Makes Emergency Repairs

    Science.gov (United States)

    1974-01-01

    APOLLO 13: Support on the ground design emergency equipment for the crew of Aquarius, and then radio instructions From the film documentary 'APOLLO 13: 'Houston, We've got a problem'', part of a documentary series on the APOLLO missions made in the early '70's and narrated by Burgess Meredith. APOLO 13 : Third manned lunar landing attempt with James A. Lovell, Jr., John L. Swigert, Jr., and Fred w. Haise, Jr. Pressure lost in SM oxygen system; mission aborted; LM used for life support. Mission Duration 142hrs 54mins 41sec

  10. Crew Management Processes Revitalize Patient Care

    Science.gov (United States)

    2009-01-01

    In 2005, two physicians, former NASA astronauts, created LifeWings Partners LLC in Memphis, Tennessee and began using Crew Resource Management (CRM) techniques developed at Ames Research Center in the 1970s to help improve safety and efficiency at hospitals. According to the company, when hospitals follow LifeWings? training, they can see major improvements in a number of areas, including efficiency, employee satisfaction, operating room turnaround, patient advocacy, and overall patient outcomes. LifeWings has brought its CRM training to over 90 health care organizations and annual sales have remained close to $3 million since 2007.

  11. The Fastest Saccadic Responses Escape Visual Masking

    DEFF Research Database (Denmark)

    M. Crouzet, Sébastien; Overgaard, Morten; Busch, Niko A.

    2014-01-01

    , which gives access to very early stages of visual processing, target visibility was reduced either by OSM, conventional backward masking, or low stimulus contrast. A general reduction of performance was observed in all three conditions. However, the fastest saccades did not show any sign of interference......Object-substitution masking (OSM) occurs when a briefly presented target in a search array is surrounded by small dots that remain visible after the target disappears. The reduction of target visibility occurring after OSM has been suggested to result from a specific interference with reentrant...... visual processing while the initial feedforward processing is thought to be left intact. We tested a prediction derived from this hypothesis: the fastest responses, being triggered before the beginning of reentrant processing, should escape the OSM interference. In a saccadic choice reaction time task...

  12. 77 FR 19148 - Special Conditions: Airbus, A350-900 Series Airplane; Crew Rest Compartments

    Science.gov (United States)

    2012-03-30

    ...-900 Series Airplane; Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... separate Crew Rest Compartments: a Flight Crew Rest Compartment (FCRC) intended to be occupied by flight crew members only, and a Cabin Crew Rest Compartment (CCRC) intended to be occupied by cabin...

  13. Risk factors for skin cancer among Finnish airline cabin crew.

    Science.gov (United States)

    Kojo, Katja; Helminen, Mika; Pukkala, Eero; Auvinen, Anssi

    2013-07-01

    Increased incidence of skin cancers among airline cabin crew has been reported in several studies. We evaluated whether the difference in risk factor prevalence between Finnish airline cabin crew and the general population could explain the increased incidence of skin cancers among cabin crew, and the possible contribution of estimated occupational cosmic radiation exposure. A self-administered questionnaire survey on occupational, host, and ultraviolet radiation exposure factors was conducted among female cabin crew members and females presenting the general population. The impact of occupational cosmic radiation dose was estimated in a separate nested case-control analysis among the participating cabin crew (with 9 melanoma and 35 basal cell carcinoma cases). No considerable difference in the prevalence of risk factors of skin cancer was found between the cabin crew (N = 702) and the general population subjects (N = 1007) participating the study. The mean risk score based on all the conventional skin cancer risk factors was 1.43 for cabin crew and 1.44 for general population (P = 0.24). Among the cabin crew, the estimated cumulative cosmic radiation dose was not related to the increased skin cancer risk [adjusted odds ratio (OR) = 0.75, 95% confidence interval (CI): 0.57-1.00]. The highest plausible risk of skin cancer for estimated cosmic radiation dose was estimated as 9% per 10 mSv. The skin cancer cases had higher host characteristics scores than the non-cases among cabin crew (adjusted OR = 1.43, 95% CI: 1.01-2.04). Our results indicate no difference between the female cabin crew and the general female population in the prevalence of factors generally associated with incidence of skin cancer. Exposure to cosmic radiation did not explain the excess of skin cancer among the studied cabin crew in this study.

  14. Stochastic narrow escape in molecular and cellular biology analysis and applications

    CERN Document Server

    Holcman, David

    2015-01-01

    This book covers recent developments in the non-standard asymptotics of the mathematical narrow escape problem in stochastic theory, as well as applications of the narrow escape problem in cell biology. The first part of the book concentrates on mathematical methods, including advanced asymptotic methods in partial equations, and is aimed primarily at applied mathematicians and theoretical physicists who are interested in biological applications. The second part of the book is intended for computational biologists, theoretical chemists, biochemists, biophysicists, and physiologists. It includes a summary of output formulas from the mathematical portion of the book and concentrates on their applications in modeling specific problems in theoretical molecular and cellular biology. Critical biological processes, such as synaptic plasticity and transmission, activation of genes by transcription factors, or double-strained DNA break repair, are controlled by diffusion in structures that have both large and small sp...

  15. The Origins and Underpinning Principles of E-Scape

    Science.gov (United States)

    Kimbell, Richard

    2012-01-01

    In this article I describe the context within which we developed project e-scape and the early work that laid the foundations of the project. E-scape (e-solutions for creative assessment in portfolio environments) is centred on two innovations. The first concerns a web-based approach to portfolio building; allowing learners to build their…

  16. Green Pea Galaxies Reveal Secrets of Lyα Escape

    Science.gov (United States)

    Yang, Huan; Malhotra, Sangeeta; Gronke, Max; Rhoads, James E.; Dijkstra, Mark; Jaskot, Anne; Zheng, Zhenya; Wang, Junxian

    2016-04-01

    We analyze archival Lyα spectra of 12 “Green Pea” galaxies observed with the Hubble Space Telescope, model their Lyα profiles with radiative transfer models, and explore the dependence of the Lyα escape fraction on various properties. Green Pea galaxies are nearby compact starburst galaxies with [O iii] λ5007 equivalent widths (EWs) of hundreds of Å. All 12 Green Pea galaxies in our sample show Lyα lines in emission, with an Lyα EW distribution similar to high-redshift Lyα emitters. Combining the optical and UV spectra of Green Pea galaxies, we estimate their Lyα escape fractions and find correlations between Lyα escape fraction and kinematic features of Lyα profiles. The escape fraction of Lyα in these galaxies ranges from 1.4% to 67%. We also find that the Lyα escape fraction depends strongly on metallicity and moderately on dust extinction. We compare their high-quality Lyα profiles with single H i shell radiative transfer models and find that the Lyα escape fraction anticorrelates with the derived H i column densities. Single-shell models fit most Lyα profiles well, but not the ones with the highest escape fractions of Lyα. Our results suggest that low H i column density and low metallicity are essential for Lyα escape and make a galaxy an Lyα emitter.

  17. Behavioural asymmetry affects escape performance in a teleost fish

    NARCIS (Netherlands)

    Dadda, Marco; Koolhaas, Wouter H.; Domenici, Paolo

    2010-01-01

    Escape performance is fundamental for survival in fish and most other animals. While previous work has shown that both intrinsic (e.g. size, shape) and extrinsic (e.g. temperature, hypoxia) factors can affect escape performance, the possibility that behavioural asymmetry may affect timing and locomo

  18. 46 CFR 169.313 - Means of escape.

    Science.gov (United States)

    2010-10-01

    ... a hold-back to hold the scuttle in an open position. (e) The required means of escape must not have... escape is acceptable provided that— (1) There is no source of fire in the space, such as a galley stove... back of the ladder; and (4) Except when unavoidable obstructions are encountered, there must be...

  19. How many ions have escaped the Martian atmosphere?

    Science.gov (United States)

    Brain, David; McFadden, James; Halekas, Jasper; Connerney, J. E. P.; Eparvier, Frank; Mitchell, David; Bougher, Stephen W.; Bowers, Charlie; Curry, Shannon; Dong, Chuanfei; Dong, Yaxue; Egan, Hilary; Fang, Xiaohua; Harada, Yuki; Jakosky, Bruce; Lillis, Robert; Luhmann, Janet; Ma, Yingjuan; Modolo, Ronan; Weber, Tristan

    2016-10-01

    The Mars Atmosphere and Volatile EvolutioN (MAVEN) mission has been making science measurements of the Martian upper atmosphere and its escape to space since November 2014. A key part of this effort is the measurement of the escape rates of charged particles (ions) at present and over solar system history. The lack of a global dynamo magnetic field at Mars leaves its upper atmosphere more directly exposed to the impinging solar wind than magnetized planets such as Earth. For this reason it is thought that ion escape at Mars may have played a significant role in long term climate change. MAVEN measures escaping planetary ions directly, with high energy, mass, and time resolution.With nearly two years of observations in hand, we will report the average ion escape rate and the spatial distribution of escaping ions as measured by MAVEN and place them in context with previous measurements of ion loss by other spacecraft (e.g. Phobos 2 and Mars Express). We will then report on the measured variability in ion escape rates with different drivers (e.g. solar EUV, solar wind pressure, etc.). Finally, we will use these results to provide an initial estimate of the total ion escape from Mars over billions of years.

  20. Escape response of planktonic protists to fluid mechanical signals

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik

    2001-01-01

    The escape response to fluid mechanical signals was examined in 6 protists, 4 ciliates and 2 dinoflagellates. When exposed to a siphon flow. 3 species of ciliates, Balanion comatum, Strobilidium sp., and Mesodinium pulex, responded with escape jumps. The threshold deformation rates required...

  1. 19 CFR 122.49c - Master crew member list and master non-crew member list requirement for commercial aircraft...

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Master crew member list and master non-crew member... Commercial Aircraft Arriving In, Continuing Within, and Overflying the United States § 122.49c Master crew member list and master non-crew member list requirement for commercial aircraft arriving in,...

  2. Crew coordination issues of EVS approaches

    Science.gov (United States)

    Lorenz, Bernd; Korn, Bernd R.

    2004-08-01

    Enhanced Vision Systems (EVS) are currently developed with the goal to alleviate restrictions in airspace and airport capacity in low visibility conditions. Existing EVS-systems are based on IR-sensors although the penetration of bad weather (dense fog and light rain) by MMW-radar is remarkably better than in the infrared spectrum. But the quality of MMW radar is rather poor compared to IR images. However, the analysis of radar images can be simplified dramatically when simple passive radar retro-reflectors are used to mark the runway. This presentation is the third in a series of studies investigating the use of such simple landing aids. In the first study the feasibility of the radar PAPI concept was determined; the second one provided first promising human performance results in a low-fidelity simulation. The present study examined pilot performance, workload, situation awareness, and crew coordination issues in a high-fidelity simulation of 'Radar-PAPI' visual aids supporting a precision straight-in landing in low visibility (CAT-II). Simulation scenarios were completed in a fixed-base cockpit simulator involving six two-pilot flight-deck crews. Pilots could derive visual cues to correct lateral glide-path deviations from 13 pairs of runway-marking corner reflectors. Vertical deviations were indicated by a set of six diplane reflectors using intensity-coding to provide the PAPI categories needed for the correction of vertical deviations. The study compared three display formats and associated crew coordination issues: (1) PF views a head-down B-scope display and switches to visual landing upon PNF's call-out that runway is in sight; (2) PF views a head-down C-scope display and switches to visual landing upon PNF's call-out that runway is in sight; (3) PF views through a head-up display (HUD) that displays primary flight guidance information and receives vertical and lateral guidance from PNF who views a head-down B-scope. PNF guidance is terminated upon PF

  3. APOLLO SOYUZ TEST PROJECT [ASTP] CREWS ADDRESS PERSONNEL IN LCC

    Science.gov (United States)

    1975-01-01

    The Soviet and American crews for the July Apollo Soyuz Test Project [standing, center] addressed personnel assembled in a firing room at KSC on February 10. The crews for the joint manned space mission toured the Center during their three-day visit which also included inspection of ASTP equipment and facilities and a trip to Disney World.

  4. 14 CFR 91.1061 - Augmented flight crews.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Augmented flight crews. 91.1061 Section 91...) AIR TRAFFIC AND GENERAL OPERATING RULES GENERAL OPERATING AND FLIGHT RULES Fractional Ownership Operations Program Management § 91.1061 Augmented flight crews. (a) No program manager may assign any...

  5. Rowing Crew Coordination Dynamics at Increasing Stroke Rates

    NARCIS (Netherlands)

    Cuijpers, Laura S.; Zaal, Frank T. J. M.; de Poel, Harjo J.

    2015-01-01

    In rowing, perfect synchronisation is important for optimal performance of a crew. Remarkably, a recent study on ergometers demonstrated that antiphase crew coordination might be mechanically more efficient by reducing the power lost to within-cycle velocity fluctuations of the boat. However, couple

  6. High Speed Lunar Navigation for Crewed and Remotely Piloted Vehicles

    Science.gov (United States)

    Pedersen, L.; Allan, M.; To, V.; Utz, H.; Wojcikiewicz, W.; Chautems, C.

    2010-01-01

    Increased navigation speed is desirable for lunar rovers, whether autonomous, crewed or remotely operated, but is hampered by the low gravity, high contrast lighting and rough terrain. We describe lidar based navigation system deployed on NASA's K10 autonomous rover and to increase the terrain hazard situational awareness of the Lunar Electric Rover crew.

  7. 14 CFR 135.99 - Composition of flight crew.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Composition of flight crew. 135.99 Section... REQUIREMENTS: COMMUTER AND ON DEMAND OPERATIONS AND RULES GOVERNING PERSONS ON BOARD SUCH AIRCRAFT Flight Operations § 135.99 Composition of flight crew. (a) No certificate holder may operate an aircraft with...

  8. Split-second escape decisions in blue tits (Parus caeruleus)

    Science.gov (United States)

    Lind, Johan; Kaby, Ulrika; Jakobsson, Sven

    2002-07-01

    Bird mortality is heavily affected by birds of prey. Under attack, take-off is crucial for survival and even minor mistakes in initial escape response can have devastating consequences. Birds may respond differently depending on the character of the predator's attack and these split-second decisions were studied using a model merlin (Falco columbarius) that attacked feeding blue tits (Parus caeruleus) from two different attack angles in two different speeds. When attacked from a low attack angle they took off more steeply than when attacked from a high angle. This is the first study to show that escape behaviour also depends on predator attack speed. The blue tits responded to a high-speed attack by dodging sideways more often than when attacked at a low speed. Escape speed was not significantly affected by the different treatments. Although they have only a split-second before escaping an attack, blue tits do adjust their escape strategy to the prevailing attack conditions.

  9. Escaping in couples facilitates evacuation: Experimental study and modeling

    CERN Document Server

    Guo, Ning; Hu, Mao-Bin; Ding, Jian-Xun; Ding, Zhong-Jun

    2015-01-01

    In this paper, the impact of escaping in couples on the evacuation dynamics has been investigated via experiments and modeling. Two sets of experiments have been implemented, in which pedestrians are asked to escape either in individual or in couples. The experiments show that escaping in couples can decrease the average evacuation time. Moreover, it is found that the average evacuation time gap is essentially constant, which means that the evacuation speed essentially does not depend on the number of pedestrians that have not yet escaped. To model the evacuation dynamics, an improved social force model has been proposed, in which it is assumed that the driving force of a pedestrian cannot be fulfilled when the composition of physical forces exceeds a threshold because the pedestrian cannot keep his/her body balance under this circumstance. To model the effect of escaping in couples, attraction force has been introduced between the partners. Simulation results are in good agreement with the experimental ones.

  10. Application of operational car crew universal speed stenogram

    Directory of Open Access Journals (Sweden)

    Volodymyr Gradusov

    2014-12-01

    Full Text Available Purpose: experimentally to check up possibility and efficiency of application of operative cars of universal speed shorthand records of unknown roads crews. Materials and Methods: theoretical analysis and generalization, pedagogical supervisions, pedagogical experiment, methods of mathematical statistics. In research took part 20 professional crews road patrol State Automobile Inspectorate, in all 40 persons, up-diffused on 2 groups for 10 crews: experimental and control. Results: application of methods of universal speed shorthand record of СД an experimental group allowed to shorten time-of-flight of segment of control distance on 7,37%. Conclusion: the results of pedagogical experiment at participation of professional crews road patrol State Automobile Inspectorate on official cars in the contention terms of the real route testify to possibility and efficiency of application of operative cars of the special setting of universal speed shorthand records of unknown roads crews during their professional activity.

  11. STS-110 Crew Interview: Jerry Ross

    Science.gov (United States)

    2002-01-01

    STS-110 Mission Specialist Jerry Ross is seen during this preflight interview, where he gives a quick overview of the mission before answering questions about his inspiration to become an astronaut and his career path. Ross outlines his role in the mission in general, and specifically during the docking and extravehicular activities (EVAs). He describes the payload (S0 Truss and Mobile Transporter) and the dry run installation of the S0 truss that will take place the day before the EVA for the actual installation. Ross discusses the planned EVAs in detail and outlines what supplies will be left for the resident crew of the International Space Station (ISS). He ends with his thoughts on the most valuable aspect of the ISS.

  12. STS-88 Crew Interview: Jerry Ross

    Science.gov (United States)

    1998-01-01

    Jerry Ross discusses the seven-day mission that will be highlighted by the mating of the U.S.-built Node 1 station element to the Functional Energy Block (FGB) which will already be in orbit, and two spacewalks to connect power and data transmission cables between the Node and the FGB. Node 1 will be the first Space Station hardware delivered by the Space Shuttle. He also disscusses the assembly sequence. The crew will conduct a series of rendezvous maneuvers similar to those conducted on other Shuttle missions to reach the orbiting FGB. Once the two elements are docked, Ross and Newman will conduct two scheduled spacewalks to connect power and data cables between the Node, PMAs and the FGB. The day following the spacewalks, Endeavour will undock from the two components, completing the first Space Station assembly mission.

  13. STS-110 Crew Interviews: Steve Smith

    Science.gov (United States)

    2002-01-01

    STS-110 Mission Specialist Steve Smith is seen during this preflight interview, where he gives a quick overview of the mission before answering questions about his inspiration to become an astronaut and his career path. Smith outlines his role in the mission in general, and specifically during the docking and extravehicular activities (EVAs). He describes the payload (S0 Truss and Mobile Transporter) and the dry run installation of the S0 truss that will take place the day before the EVA for the actual installation. Smith discusses the planned EVAs in detail and outlines what supplies will be left for the resident crew of the International Space Station (ISS). He ends with his thoughts on the most valuable aspect of the ISS.

  14. The Home Care Crew Scheduling Problem:

    DEFF Research Database (Denmark)

    Rasmussen, Matias Sevel; Justesen, Tor; Dohn, Anders

    In the Home Care Crew Scheduling Problem a staff of caretakers has to be assigned a number of visits to patients' homes, such that the overall service level is maximised. The problem is a generalisation of the vehicle routing problem with time windows. Required travel time between visits and time...... windows of the visits must be respected. The challenge when assigning visits to caretakers lies in the existence of soft preference constraints and in temporal dependencies between the start times of visits. We model the problem as a set partitioning problem with side constraints and develop an exact...... branch-and-price solution algorithm, as this method has previously given solid results for classical vehicle routing problems. Temporal dependencies are modelled as generalised precedence constraints and enforced through the branching. We introduce a novel visit clustering approach based on the soft...

  15. STS-96 Crew Training, Mission Animation, Crew Interviews, STARSHINE, Discovery Rollout and Repair of Hail Damage

    Science.gov (United States)

    1999-01-01

    Live footage shows the crewmembers of STS-96, Commander Kent V. Rominger, Pilot Rick D. Husband, Mission Specialists Ellen Ochoa, Tamara E. Jernigan, Daniel T. Barry, Julie Payette and Valery Ivanovich Tokarev during various training activities. Scenes include astronaut suit-up, EVA training in the Virtual Reality Lab, Orbiter space vision training, bailout training, and crew photo session. Footage also shows individual crew interviews, repair activities to the external fuel tank, and Discovery's return to the launch pad. The engineers are seen sanding, bending, and painting the foam used in repairing the tank. An animation of the deployment of the STARSHINE satellite, International Space Station, and the STS-96 Mission is presented. Footage shows the students from Edgar Allen Poe Middle School sanding, polishing, and inspecting the mirrors for the STARSHINE satellite. Live footage also includes students from St. Michael the Archangel School wearing bunny suits and entering the clean room at Goddard Space Flight Center.

  16. An Analysis of Shuttle Crew Scheduling Violations

    Science.gov (United States)

    Bristol, Douglas

    2012-01-01

    From the early years of the Space Shuttle program, National Aeronautics and Space Administration (NASA) Shuttle crews have had a timeline of activities to guide them through their time on-orbit. Planners used scheduling constraints to build timelines that ensured the health and safety of the crews. If a constraint could not be met it resulted in a violation. Other agencies of the federal government also have scheduling constraints to ensure the safety of personnel and the public. This project examined the history of Space Shuttle scheduling constraints, constraints from Federal agencies and branches of the military and how these constraints may be used as a guide for future NASA and private spacecraft. This was conducted by reviewing rules and violations with regard to human aerospace scheduling constraints, environmental, political, social and technological factors, operating environment and relevant human factors. This study includes a statistical analysis of Shuttle Extra Vehicular Activity (EVA) related violations to determine if these were a significant producer of constraint violations. It was hypothesized that the number of SCSC violations caused by EVA activities were a significant contributor to the total number of violations for Shuttle/ISS missions. Data was taken from NASA data archives at the Johnson Space Center from Space Shuttle/ISS missions prior to the STS-107 accident. The results of the analysis rejected the null hypothesis and found that EVA violations were a significant contributor to the total number of violations. This analysis could help NASA and commercial space companies understand the main source of constraint violations and allow them to create constraint rules that ensure the safe operation of future human private and exploration missions. Additional studies could be performed to evaluate other variables that could have influenced the scheduling violations that were analyzed.

  17. Special Purpose Crew Restraints for Teleoperation

    Science.gov (United States)

    Whitmore, Mihriban; Holden, Kritina; Norris, Lena

    2004-01-01

    With permanent human presence onboard the International Space Station (ISS), and long duration space missions being planned for the moon and Mars, humans will be living and working in microgravity over increasingly long periods of time. In addition to weightlessness, the confined nature of a spacecraft environment results in ergonomic challenges such as limited visibility, and access to the activity area. These challenges can result in prolonged periods of unnatural postures for the crew, ultimately causing pain, injury, and loss of productivity. Determining the right set of human factors requirements and providing an ergonomically designed environment is crucial to mission success. While a number of general purpose restraints have been used on ISS (handrails, foot loops), experience has shown that these general purpose restraints may not be optimal, or even acceptable for some tasks that have unique requirements. For example, some onboard activities require extreme stability (e.g., glovebox microsurgery), and others involve the use of arm, torso and foot movements in order to perform the task (e-g. robotic teleoperation); standard restraint systems will not work in these situations. The Usability Testing and Analysis Facility (WAF) at the NASA Johnson Space Center began evaluations of crew restraints for these special situations by looking at NASAs Robonaut. Developed by the Robot Systems Technology Branch, Robonaut is a humanoid robot that can be remotely operated through a tetepresence control system by an operator. It was designed to perform work in hazardous environments (e.g., Extra Vehicular Activities). A Robonaut restraint was designed, modeled for the population, and ultimately tested onboard the KC-135 microgravity aircraft. While in microgravity, participants were asked to get in and out of the restraint from different locations, perform maximum reach exercises, and finally to teleoperate Robonaut while in the restraint. The sessions were videotaped

  18. Theory underlying CRM training: Psychological issues in flight crew performance and crew coordination

    Science.gov (United States)

    Helmreich, Robert L.

    1987-01-01

    What psychological theory and research can reveal about training in Cockpit Resource Management (CRM) is summarized. A framework is provided for the critical analysis of current approaches to CRM training. Background factors and definitions critical to evaluating CRM are reviewed, followed by a discussion of issues directly related to CRM training effectiveness. Some of the things not known about the optimization of crew performance and the research needed to make these efforts as effective as possible are described.

  19. The fastest saccadic responses escape visual masking.

    Directory of Open Access Journals (Sweden)

    Sébastien M Crouzet

    Full Text Available Object-substitution masking (OSM occurs when a briefly presented target in a search array is surrounded by small dots that remain visible after the target disappears. The reduction of target visibility occurring after OSM has been suggested to result from a specific interference with reentrant visual processing while the initial feedforward processing is thought to be left intact. We tested a prediction derived from this hypothesis: the fastest responses, being triggered before the beginning of reentrant processing, should escape the OSM interference. In a saccadic choice reaction time task, which gives access to very early stages of visual processing, target visibility was reduced either by OSM, conventional backward masking, or low stimulus contrast. A general reduction of performance was observed in all three conditions. However, the fastest saccades did not show any sign of interference under either OSM or backward masking, as they did under the low-contrast condition. This finding supports the hypothesis that masking interferes mostly with reentrant processing at later stages, while leaving early feedforward processing largely intact.

  20. Candida albicans escapes from mouse neutrophils.

    Science.gov (United States)

    Ermert, David; Niemiec, Maria J; Röhm, Marc; Glenthøj, Andreas; Borregaard, Niels; Urban, Constantin F

    2013-08-01

    Candida albicans, the most commonly isolated human fungal pathogen, is able to grow as budding yeasts or filamentous forms, such as hyphae. The ability to switch morphology has been attributed a crucial role for the pathogenesis of C. albicans. To mimic disseminated candidiasis in humans, the mouse is the most widely used model organism. Neutrophils are essential immune cells to prevent opportunistic mycoses. To explore potential differences between the rodent infection model and the human host, we compared the interactions of C. albicans with neutrophil granulocytes from mice and humans. We revealed that murine neutrophils exhibited a significantly lower ability to kill C. albicans than their human counterparts. Strikingly, C. albicans yeast cells formed germ tubes upon internalization by murine neutrophils, eventually rupturing the neutrophil membrane and thereby, killing the phagocyte. On the contrary, growth and subsequent escape of C. albicans are blocked inside human neutrophils. According to our findings, this blockage in human neutrophils might be a result of higher levels of MPO activity and the presence of α-defensins. We therefore outline differences in antifungal immune defense between humans and mouse strains, which facilitates a more accurate interpretation of in vivo results.

  1. Immune Escape Strategies of Malaria Parasites

    Science.gov (United States)

    Gomes, Pollyanna S.; Bhardwaj, Jyoti; Rivera-Correa, Juan; Freire-De-Lima, Celio G.; Morrot, Alexandre

    2016-01-01

    Malaria is one of the most life-threatening infectious diseases worldwide. Immunity to malaria is slow and short-lived despite the repeated parasite exposure in endemic areas. Malaria parasites have evolved refined machinery to evade the immune system based on a range of genetic changes that include allelic variation, biomolecular exposure of proteins, and intracellular replication. All of these features increase the probability of survival in both mosquitoes and the vertebrate host. Plasmodium species escape from the first immunological trap in its invertebrate vector host, the Anopheles mosquitoes. The parasites have to pass through various immunological barriers within the mosquito such as anti-microbial molecules and the mosquito microbiota in order to achieve successful transmission to the vertebrate host. Within these hosts, Plasmodium species employ various immune evasion strategies during different life cycle stages. Parasite persistence against the vertebrate immune response depends on the balance among virulence factors, pathology, metabolic cost of the host immune response, and the parasites ability to evade the immune response. In this review we discuss the strategies that Plasmodium parasites use to avoid the vertebrate host immune system and how they promote successful infection and transmission. PMID:27799922

  2. Flight Crew Training: Multi-Crew Pilot License Training versus Traditional Training and Its Relationship with Job Performance

    Science.gov (United States)

    Cushing, Thomas S.

    2013-01-01

    In 2006, the International Civil Aviation Organization promulgated requirements for a Multi-Crew Pilot License for First Officers, in which the candidate attends approximately two years of ground school and trains as part of a two-person crew in a simulator of a Boeing 737 or an Airbus 320 airliner. In the traditional method, a candidate qualifies…

  3. Piloted Simulator Evaluation of Maneuvering Envelope Information for Flight Crew Awareness

    Science.gov (United States)

    Lombaerts, Thomas; Schuet, Stefan; Acosta, Diana; Kaneshige, John; Shish, Kimberlee; Martin, Lynne

    2015-01-01

    The implementation and evaluation of an efficient method for estimating safe aircraft maneuvering envelopes are discussed. A Bayesian approach is used to produce a deterministic algorithm for estimating aerodynamic system parameters from existing noisy sensor measurements, which are then used to estimate the trim envelope through efficient high- fidelity model-based computations of attainable equilibrium sets. The safe maneuverability limitations are extended beyond the trim envelope through a robust reachability analysis derived from an optimal control formulation. The trim and maneuvering envelope limits are then conveyed to pilots through three axes on the primary flight display. To evaluate the new display features, commercial airline crews flew multiple challenging approach and landing scenarios in the full motion Advanced Concepts Flight Simulator at NASA Ames Research Center, as part of a larger research initiative to investigate the impact on the energy state awareness of the crew. Results show that the additional display features have the potential to significantly improve situational awareness of the flight crew.

  4. Efficiently estimating salmon escapement uncertainty using systematically sampled data

    Science.gov (United States)

    Reynolds, Joel H.; Woody, Carol Ann; Gove, Nancy E.; Fair, Lowell F.

    2007-01-01

    Fish escapement is generally monitored using nonreplicated systematic sampling designs (e.g., via visual counts from towers or hydroacoustic counts). These sampling designs support a variety of methods for estimating the variance of the total escapement. Unfortunately, all the methods give biased results, with the magnitude of the bias being determined by the underlying process patterns. Fish escapement commonly exhibits positive autocorrelation and nonlinear patterns, such as diurnal and seasonal patterns. For these patterns, poor choice of variance estimator can needlessly increase the uncertainty managers have to deal with in sustaining fish populations. We illustrate the effect of sampling design and variance estimator choice on variance estimates of total escapement for anadromous salmonids from systematic samples of fish passage. Using simulated tower counts of sockeye salmon Oncorhynchus nerka escapement on the Kvichak River, Alaska, five variance estimators for nonreplicated systematic samples were compared to determine the least biased. Using the least biased variance estimator, four confidence interval estimators were compared for expected coverage and mean interval width. Finally, five systematic sampling designs were compared to determine the design giving the smallest average variance estimate for total annual escapement. For nonreplicated systematic samples of fish escapement, all variance estimators were positively biased. Compared to the other estimators, the least biased estimator reduced bias by, on average, from 12% to 98%. All confidence intervals gave effectively identical results. Replicated systematic sampling designs consistently provided the smallest average estimated variance among those compared.

  5. Lyman-Werner UV escape fractions from primordial haloes

    Science.gov (United States)

    Schauer, Anna T. P.; Whalen, Daniel J.; Glover, Simon C. O.; Klessen, Ralf S.

    2015-12-01

    Population III (Pop III) stars can regulate star formation in the primordial Universe in several ways. They can ionize nearby haloes, and even if their ionizing photons are trapped by their own haloes, their Lyman-Werner (LW) photons can still escape and destroy H2 in other haloes, preventing them from cooling and forming stars. LW escape fractions are thus a key parameter in cosmological simulations of early reionization and star formation but have not yet been parametrized for realistic haloes by halo or stellar mass. To do so, we perform radiation hydrodynamical simulations of LW UV escape from 9-120 M⊙ Pop III stars in 105-107 M⊙ haloes with ZEUS-MP. We find that photons in the LW lines (i.e. those responsible for destroying H2 in nearby systems) have escape fractions ranging from 0 to 85 per cent. No LW photons escape the most massive halo in our sample, even from the most massive star. Escape fractions for photons elsewhere in the 11.18-13.6 eV energy range, which can be redshifted into the LW lines at cosmological distances, are generally much higher, being above 60 per cent for all but the least massive stars in the most massive haloes. We find that shielding of H2 by neutral hydrogen, which has been neglected in most studies to date, produces escape fractions that are up to a factor of 3 smaller than those predicted by H2 self-shielding alone.

  6. Observations of Crew Dynamics during Mars Analog Simulations

    Science.gov (United States)

    Cusack, Stacy L.

    2010-01-01

    This presentation reviews the crew dynamics during two simulations of Mars Missions. Using an analog of a Mars habitat in two locations, Flashline Mars Arctic Research Station (FMARS) which is located on Devon Island at 75 deg North in the Canadian Arctic, and the Mars Desert Research Station (MDRS) which is located in the south of Utah, the presentation examines the crew dynamics in relation to the leadership style of the commander of the mission. The difference in the interaction of the two crews were shown to be related to the leadership style and the age group in the crew. As much as possible the habitats and environment was to resemble a Mars outpost. The difference between the International Space Station and a Mars missions is reviewed. The leadership styles are reviewed and the contrast between the FMARS and the MDRS leadership styles were related to crew productivity, and the personal interactions between the crew members. It became evident that leadership styles and interpersonal skill had more affect on mission success and crew dynamics than other characteristics.

  7. The European space suit, a design for productivity and crew safety

    Science.gov (United States)

    Skoog, A. Ingemar; Berthier, S.; Ollivier, Y.

    In order to fulfil the two major mission objectives, i.e. support planned and unplanned external servicing of the COLUMBUS FFL and support the HERMES vehicle for safety critical operations and emergencies, the European Space Suit System baseline configuration incorporates a number of design features, which shall enhance the productivity and the crew safety of EVA astronauts. The work in EVA is today - and will be for several years - a manual work. Consequently, to improve productivity, the first challenge is to design a suit enclosure which minimizes movement restrictions and crew fatigue. It is covered by the "ergonomic" aspect of the suit design. Furthermore, it is also necessary to help the EVA crewmember in his work, by giving him the right information at the right time. Many solutions exist in this field of Man-Machine Interface, from a very simple system, based on cuff check lists, up to advanced systems, including Head-Up Displays. The design concept for improved productivity encompasses following features: • easy donning/doffing thru rear entry, • suit ergonomy optimisation, • display of operational information in alpha-numerical and graphical from, and • voice processing for operations and safety critical information. Concerning crew safety the major design features are: • a lower R-factor for emergency EVA operations thru incressed suit pressure, • zero prebreath conditions for normal operations, • visual and voice processing of all safety critical functions, and • an autonomous life support system to permit unrestricted operations around HERMES and the CFFL. The paper analyses crew safety and productivity criteria and describes how these features are being built into the design of the European Space Suit System.

  8. Constraints on Bounded Motion and Mutual Escape for the Full 3-Body Problem

    CERN Document Server

    Scheeres, D J

    2016-01-01

    When gravitational aggregates are spun to fission they can undergo complex dynamical evolution, including escape and reconfiguration. Previous work has shown that a simple analysis of the full 2-body problem provides physically relevant insights for whether a fissioned system can lead to escape of the components and the creation of asteroid pairs. In this paper we extend the analysis to the full 3-body problem, utilizing recent advances in the understanding of fission mechanics of these systems. Specifically, we find that the full 3-body problem can eject a body with as much as 0.31 of the total system mass, significantly larger than the 0.17 mass limit previously calculated for the full 2-body problem. This paper derives rigorous limits on a fissioned 3-body system with regards to whether fissioned system components can physically escape from each other and what other stable relative equilibria they could settle in. We explore this question with a narrow focus on the Spherical Full Three Body Problem studied...

  9. The Single Crew Module Concept for Exploration

    Science.gov (United States)

    Chambliss, Joe

    2012-01-01

    Many concepts have been proposed for exploring space. In early 2010 presidential direction called for reconsidering the approach to address changes in exploration destinations, use of new technologies and development of new capabilities to support exploration of space. Considering the proposed new technology and capabilities that NASA was directed to pursue, the single crew module (SCM) concept for a more streamlined approach to the infrastructure and conduct of exploration missions was developed. The SCM concept combines many of the new promising technologies with a central concept of mission architectures that uses a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them prior to departure of the vicinity of Earth provides the capability of using the single habitat both in transit to an exploration destination and while exploring the destination. The concept employs the capability to return the habitat and interplanetary propulsion system to Earth vicinity so that those elements can be reused on subsequent exploration missions. This paper describes the SCM concept, provides a top level mass estimate for the elements needed and trades the concept against Many concepts have been proposed for exploring space. In early 2010 presidential direction called for reconsidering the approach to address changes in exploration destinations, use of new technologies and development of new capabilities to support exploration of space. Considering the proposed new technology and capabilities that NASA was directed to pursue, the single crew module (SCM) concept for a more streamlined approach to the infrastructure and conduct of exploration missions was developed. The SCM concept combines many of the new promising technologies with a central concept of mission architectures that uses a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them

  10. Can we escape from the big rip in the achronal cosmic future?

    CERN Document Server

    Yurov, A V; Vereshchagin, S D

    2005-01-01

    Recently Pedro F. Gonzalez-Diaz had shown that phantom energy can results in achronal cosmic future where the wormholes become infinite before the occurrence of the big rip singularity. After that, while the phantom energy continues its accretion, any wormhole becomes the Einstein-Rosen bridge. Pedro F. Gonzalez-Diaz has suggested that such objects can be used by an advanced civilization as the means of escape from the big rip. Using the Bekenstein Bound we'll show that it is impossible due to the very strong upper bound laid on the total amount of information which can be sent through this bridge.

  11. On the large escape of ionizing radiation from GEHRs

    CERN Document Server

    Castellanos, M; Tenorio-Tagle, G

    2001-01-01

    A thorough analysis of well studied giant HII regions on galactic discs for which we know the ionizing stellar population, the gas metallicity and the Wolf-Rayet population, leads to photoionization models which can only match all observed line intensity ratios ([OIII], [OII], [NII], [SII] and [SIII] with respect to the intensity of H$\\beta$), as well as the H$\\beta$ luminosity and equivalent width if one allows for an important escape of energetic ionizing radiation. For the three regions presented here, the fractions of escaping Lyman continuum photons amount to 10 to 73 % and, in all cases, the larger fraction of escaping photons has energies between 13.6 and 24.4 eV. These escaping photons clearly must have an important impact as a source of ionization of the diffuse ionized gas (DIG) found surrounding many galaxies, as well as of the intergalactic medium (IGM).

  12. Behavior of the Escape Rate Function in Hyperbolic Dynamical Systems

    CERN Document Server

    Demers, Mark

    2011-01-01

    For a fixed initial reference measure, we study the dependence of the escape rate on the hole for a smooth or piecewise smooth hyperbolic map. First, we prove the existence and Holder continuity of the escape rate for systems with small holes admitting Young towers. Then we consider general holes for Anosov diffeomorphisms, without size or Markovian restrictions. We prove bounds on the upper and lower escape rates using the notion of pressure on the survivor set and show that a variational principle holds under generic conditions. However, we also show that the escape rate function forms a devil's staircase with jumps along sequences of regular holes and present examples to elucidate some of the difficulties involved in formulating a general theory.

  13. Amplitude modulation control of escape from a potential well

    Energy Technology Data Exchange (ETDEWEB)

    Chacón, R. [Departamento de Física Aplicada, Escuela de Ingenierías Industriales, Universidad de Extremadura, Apartado Postal 382, E-06006 Badajoz (Spain); Martínez García-Hoz, A. [Departamento de Física Aplicada, Escuela Universitaria Politécnica, Universidad de Castilla-La Mancha, E-13400 Almadén (Ciudad Real) (Spain); Miralles, J.J. [Departamento de Física Aplicada, Escuela de Ingenieros Industriales, Universidad de Castilla-La Mancha, E-02071 Albacete (Spain); Martínez, P.J. [Departamento de Física Aplicada, E.I.N.A., Universidad de Zaragoza, E-50018 Zaragoza (Spain); Instituto de Ciencia de Materiales de Aragón, CSIC – Universidad de Zaragoza, E-50009 Zaragoza (Spain)

    2014-03-01

    We demonstrate the effectiveness of periodic amplitude modulations in controlling (suppressing and enhancing) escape from a potential well through the universal model of a damped Helmholtz oscillator subjected to an external periodic excitation (the escape-inducing excitation) whose amplitude is periodically modulated (the escape-controlling excitation). Analytical and numerical results show that this multiplicative control works reliably for different subharmonic resonances between the two periodic excitations involved, and that its effectiveness is comparable to those of different methods of additive control. Additionally, we demonstrate the robustness of the multiplicative control against the presence of low-intensity Gaussian noise. -- Highlights: •Multiplicative control of escape from a potential well has been demonstrated. •Theoretical predictions are obtained from a Melnikov analysis. •It has been shown the robustness of the multiplicative control against noise.

  14. Theoretical Study on Ion Escape in Martian Atmosphere

    Institute of Scientific and Technical Information of China (English)

    SHI Jian-Kui; LIU Zhen-Xing; Klaus TORKAR; Tielong ZHANG

    2007-01-01

    @@ Based on the observation that Martian magnetic moment is gradually reducing from the ancient to the present,we investigate the O+ ion flux distribution along magnetic field lines and the ion escaping flux in Martian tail with different assumed Martian magnetic moments. The results show that the O+ ion flux along magnetic field lines decreases with distance from Mars; the ion flux along the field line decreases more quickly if the magnetic moment is larger; the larger the magnetic moment, the smaller the ion escaping flux in the Martian tail. The ion escaping flux depends on Z-coordinate in the Martian tail. With decrease of the magnetic moment, the ion escaping flux in the Martian tail increases. The results are significant for studying the water loss from Mars surface.

  15. Oxygen Escape from Venus During High Dynamic Pressure ICMEs

    Science.gov (United States)

    McEnulty, Tess; Luhmann, J. G.; Brain, D. A.; Fedorov, A.; Jian, L. K.; Russell, C. T.; Zhang, T.; Möstl, C.; Futaana, Y.; de Pater, I.

    2013-10-01

    Previous studies using data from Pioneer Venus suggested that oxygen ion escape flux may be enhanced by orders of magnitude during Interplanetary Coronal Mass Ejections. However, this large enhancement has been ambiguous in Venus Express ion data - with some analyses showing no flux enhancement or a small enhancement (within 2 times undisturbed cases). One possible explanation is that high escape flux may be due to high dynamic pressure in the solar wind, and the dynamic pressure has been lower during the VEX time period. So, we focus on ICMEs with the largest dynamic pressure and with VEX sampling of the escaping ions during the sheath of the ICMEs (during which the highest dynamic pressures in the solar wind occur). We will show the characteristics of these large events measured by VEX, and compare them to the largest ICMEs measured by PVO. We will then discuss estimates of the oxygen ion escape flux during these events.

  16. Experimental Analysis and Extinction of Self-Injurious Escape Behavior.

    Science.gov (United States)

    Iwata, Brian A.; And Others

    1990-01-01

    Three studies investigated environmental correlates of self-injurious behavior in seven developmentally disabled children and adolescents which were then later used for treatment. Correlates investigated included positive reinforcement, negative reinforcement, automatic reinforcement, and control. "Escape extinction" was successfully…

  17. Pioneer Venus Orbiter (PVO) Ionosphere Evidence for Atmospheric Escape

    Science.gov (United States)

    Grebowsky, J. M.; Hoegy, W. R.

    2009-12-01

    An early estimate of escape of H2O from Venus [McElroy et al., 1982] using observed hot oxygen densities inferred by Nagy et al. [1981] from PVO OUVS 1304 Å dayglow and using ionization rates from photoionization and electron impact. This resulted in an estimated oxygen ionization rate planet-wide above the plasmapause of 3x1025 atoms/s. Based on the energetic O+ being swept up and removed by solar wind, McElroy et al. [1982] gave an estimate of a loss rate for O of 6x106 atoms/cm2/s. Using a different method of estimating escape based data in the ionotail of Venus, Brace et al. [1987] estimated a total planetary O+ escape rate of 5x1025 ions/s. Their estimate was based on PVO measurements of superthermal O+ (energy range 9-16 eV) in the tail ray plasma between 2000 and 3000 km. Their estimated global mean flux was 107 atoms/cm2/s. The two escape rates are remarkably close considering all the errors involved in such estimates of escape. A study of escape by Luhmann et al. [2008] using VEX observations at low solar activity finds modest escape rates, prompting the authors to reconsider the evidence from both PVO and VEX of the possibility of enhanced escape during extreme interplanetary conditions. We reexamine the variation of escape under different solar wind conditions using ion densities and plasma content in the dayside and nightside of Venus using PVO ionosphere density during times of high solar activity. Citations: Brace, L.H., W. T. Kasprzak, H.A. Taylor, R. F. Theis, C. T. Russess, A. Barnes, J. D. Mihalov, and D. M. Hunten, "The Ionotail of Venus: Its Configuration and Evidence for Ion Escape", J. Geophys. Res. 92, 15-26, 1987. Luhmann, J.G., A. Fedorov, S. Barabash, E. Carlsson, Y. Futaana, T.L. Zhang, C.T. Russell, J.G. Lyon, S.A. Ledvina, and D.A. Brain, “Venus Express observations of atmospheric oxygen escape during the passage of several coronal mass ejections”, J. Geophys. Res., 113, 2008. McElroy, M. B., M. J. Prather, J. M. Rodiquez, " Loss

  18. STS-41-D Crew Enjoying Space

    Science.gov (United States)

    1984-01-01

    Crewmembers of NASA's 41-D mission take a group shot displaying their fun moments in space aboard the orbiter Discovery. Crewmembers are (counter-clockwise from center) crew commander Henry W. Harsfield Jr., pilot Michael L. Coats, mission specialist Steven A. Hawley, mission specialist Judith A. Resnik, payload specialist Charles D. Walker, and mission specialist Richard M. Mullane. Dr. Judith Resnik is shown enjoying the weightlessness of space during her first mission. Born on April 5, 1949 in Akron, Ohio, she received a Bachelor of Science degree in Electrical Engineering from Carnegie-Mellon University in 1970, and a Doctorate in Electrical Engineering from University of Maryland in 1977. Dr. Resnik joined NASA in 1978 as a senior systems engineer in product development with Xerox Corporation at El Segundo, California. NASA later selected her as an astronaut candidate in January 1978; she completed a 1-year training and evaluation period in August 1979. Dr. Resnik died on January 28, 1986 on her second mission, during the failed launch of Challenger STS-51 L.

  19. Purinergic Inhibition of ENaC Produces Aldosterone Escape

    OpenAIRE

    Stockand, James D.; Mironova, Elena; Bugaj, Vladislav; Rieg, Timo; Insel, Paul A.; Vallon, Volker; Peti-Peterdi, Janos; Pochynyuk, Oleh

    2010-01-01

    The mechanisms underlying “aldosterone escape,” which refers to the excretion of sodium (Na+) during high Na+ intake despite inappropriately increased levels of mineralocorticoids, are incompletely understood. Because local purinergic tone in the aldosterone-sensitive distal nephron downregulates epithelial Na+ channel (ENaC) activity, we tested whether this mechanism mediates aldosterone escape. Here, urinary ATP concentration increased with dietary Na+ intake in mice. Physiologic concentrat...

  20. GREEN PEA GALAXIES REVEAL SECRETS OF Lyα ESCAPE

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huan; Wang, Junxian [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China (China); Malhotra, Sangeeta; Rhoads, James E. [Arizona State University, School of Earth and Space Exploration (United States); Gronke, Max; Dijkstra, Mark [Institute of Theoretical Astrophysics, University of Oslo (Norway); Jaskot, Anne [Smith College, Northampton, MA (United States); Zheng, Zhenya, E-mail: yanghuan@mail.ustc.edu.cn, E-mail: huan.y@asu.edu, E-mail: Sangeeta.Malhotra@asu.edu, E-mail: James.Rhoads@asu.edu [Pontificia Universidad Católica de Chile, Santiago (Chile)

    2016-04-01

    We analyze archival Lyα spectra of 12 “Green Pea” galaxies observed with the Hubble Space Telescope, model their Lyα profiles with radiative transfer models, and explore the dependence of the Lyα escape fraction on various properties. Green Pea galaxies are nearby compact starburst galaxies with [O iii] λ5007 equivalent widths (EWs) of hundreds of Å. All 12 Green Pea galaxies in our sample show Lyα lines in emission, with an Lyα EW distribution similar to high-redshift Lyα emitters. Combining the optical and UV spectra of Green Pea galaxies, we estimate their Lyα escape fractions and find correlations between Lyα escape fraction and kinematic features of Lyα profiles. The escape fraction of Lyα in these galaxies ranges from 1.4% to 67%. We also find that the Lyα escape fraction depends strongly on metallicity and moderately on dust extinction. We compare their high-quality Lyα profiles with single H i shell radiative transfer models and find that the Lyα escape fraction anticorrelates with the derived H i column densities. Single-shell models fit most Lyα profiles well, but not the ones with the highest escape fractions of Lyα. Our results suggest that low H i column density and low metallicity are essential for Lyα escape and make a galaxy an Lyα emitter.

  1. Group chase and escape with sight-limited chasers

    Science.gov (United States)

    Wang, Huodong; Han, Wenchen; Yang, Junzhong

    2017-01-01

    We study group chase and escape with sight-limited chasers. Two search strategies, random-walk-strategy and relocation-strategy, are introduced for chasers when escapers are out of their fields of vision. There exist two regimes for the group lifetime of escapers. In the narrow sight regime, the group lifetime is a decreasing function of chasers' sight range. In the wide sight regime, the group lifetime stays at a constant when chasers adopting random-walk-strategy while increases with the sight range when chasers adopting relocation-strategy. The impacts of the two search strategies on group chase and escape are studied by investigating the lifetime distribution of all escapers and the dependence of the minimum lifetime on the number of chasers. We also find that, to reach the most efficient and the lowest energy cost chase for chasers, the ratio between the number of chasers and escapers stays at around 6 under random-walk-strategy. However, the optimal number of chasers vanishes and the energy cost monotonically increases with increasing the number of chasers under relocation-strategy.

  2. Dynamics of immune escape during HIV/SIV infection.

    Directory of Open Access Journals (Sweden)

    Christian L Althaus

    Full Text Available Several studies have shown that cytotoxic T lymphocytes (CTLs play an important role in controlling HIV/SIV infection. Notably, the observation of escape mutants suggests a selective pressure induced by the CTL response. However, it remains difficult to assess the definite role of the cellular immune response. We devise a computational model of HIV/SIV infection having a broad cellular immune response targeting different viral epitopes. The CTL clones are stimulated by viral antigen and interact with the virus population through cytotoxic killing of infected cells. Consequently, the virus population reacts through the acquisition of CTL escape mutations. Our model provides realistic virus dynamics and describes several experimental observations. We postulate that inter-clonal competition and immunodominance may be critical factors determining the sequential emergence of escapes. We show that even though the total killing induced by the CTL response can be high, escape rates against a single CTL clone are often slow and difficult to estimate from infrequent sequence measurements. Finally, our simulations show that a higher degree of immunodominance leads to more frequent escape with a reduced control of viral replication but a substantially impaired replicative capacity of the virus. This result suggests two strategies for vaccine design: Vaccines inducing a broad CTL response should decrease the viral load, whereas vaccines stimulating a narrow but dominant CTL response are likely to induce escape but may dramatically reduce the replicative capacity of the virus.

  3. Lyman-Werner UV Escape Fractions from Primordial Halos

    CERN Document Server

    Schauer, Anna T P; Glover, Simon C O; Klessen, Ralf S

    2015-01-01

    Population III stars can regulate star formation in the primordial Universe in several ways. They can ionize nearby halos, and even if their ionizing photons are trapped by their own halos, their Lyman-Werner (LW) photons can still escape and destroy H$_2$ in other halos, preventing them from cooling and forming stars. LW escape fractions are thus a key parameter in cosmological simulations of early reionization and star formation but have not yet been parametrized for realistic halos by halo or stellar mass. To do so, we perform radiation hydrodynamical simulations of LW UV escape from 9--120 M$_{\\odot}$ Pop III stars in $10^5$ to $10^7$ M$_{\\odot}$ halos with ZEUS-MP. We find that photons in the LW lines (i.e. those responsible for destroying H$_{2}$ in nearby systems) have escape fractions ranging from 0% to 85%. No LW photons escape the most massive halo in our sample, even from the most massive star. Escape fractions for photons elsewhere in the 11.18--13.6~eV energy range, which can be redshifted into t...

  4. Green Pea Galaxies Reveal Secrets of Ly$\\alpha$ Escape

    CERN Document Server

    Yang, Huan; Gronke, Max; Rhoads, James E; Jaskot, Anne; Zheng, Zhenya; Dijkstra, Mark

    2015-01-01

    Star-formation in galaxies generates a lot of Ly$\\alpha$ photons. Understanding the escape of Ly$\\alpha$ photons from galaxies is a key issue in studying high redshift galaxies and probing cosmic reionization with Ly$\\alpha$. To understand Ly$\\alpha$ escape, it is valuable to study analogs of high redshift Ly$\\alpha$ emitters in nearby universe. However, most nearby analogs have too small a Ly$\\alpha$ equivalent width and escape fraction compared to high redshift Ly$\\alpha$ emitters. One different group of nearby analogs are "Green Pea" galaxies, selected by their high equivalent width optical emission lines. Here we show that Green Pea galaxies have strong Ly$\\alpha$ emission lines and high Ly$\\alpha$ escape fraction (see also Henry et al. 2015), providing an opportunity to solve Ly$\\alpha$ escape problem. Green Peas have a Ly$\\alpha$ equivalent width distribution similar to high redshift Ly$\\alpha$ emitters. The Ly$\\alpha$ escape fraction correlates with many quantities of Ly$\\alpha$ profile, especially the...

  5. Escape dynamics and fractal basin boundaries in Seyfert galaxies

    CERN Document Server

    Zotos, Euaggelos E

    2015-01-01

    The escape dynamics in a simple analytical gravitational model which describes the motion of stars in a Seyfert galaxy is investigated in detail. We conduct a thorough numerical analysis distinguishing between regular and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. In order to distinguish safely and with certainty between ordered and chaotic motion, we apply the Smaller ALingment Index (SALI) method. It is of particular interest to locate the escape basins through the openings around the collinear Lagrangian points $L_1$ and $L_2$ and relate them with the corresponding spatial distribution of the escape times of the orbits. Our exploration takes place both in the physical $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the galactic system. Our numerical analysis reveals the strong dependence of the properties of the considered escape basins with the...

  6. Cosmic rays score direct hits with Apollo crew

    CERN Multimedia

    1971-01-01

    Apollo 14 astronauts conduted experiments during the spaceflight to help scientists to understand why previous crews have seen flashes of light during missions, believed to be caused by cosmic rays (1 page).

  7. Crew Health And Recreation Gear Exercise Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A magneto-Rheological (MR) fluid based exoskeleton leg demonstrator was developed to help long duration exploration mission crews obtain exercise with entertainment...

  8. Avatar Robot for Crew Performance and Behavioral Health Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project investigates the effectiveness of using an avatar robotic platform as a crew assistant and a family member substitute. This type of avatar robot is...

  9. Planning for Crew Exercise for Deep Space Mission Scenarios

    Science.gov (United States)

    Moore, E. Cherice; Ryder, Jeff

    2015-01-01

    Exercise which is necessary for maintaining crew health on-orbit and preparing the crew for return to 1G can be challenging to incorporate into spaceflight vehicles. Deep space missions will require further understanding of the physiological response to microgravity, understanding appropriate mitigations, and designing the exercise systems to effectively provide mitigations, and integrating effectively into vehicle design with a focus to support planned mission scenarios. Recognizing and addressing the constraints and challenges can facilitate improved vehicle design and exercise system incorporation.

  10. Definition of essence of concept approaches to crewing business conduct

    OpenAIRE

    Лукашевич, Виталий Матвеевич

    2014-01-01

    It is a research of conceptual approaches to crewing business conduct. It is ascertained that their essential basements are determined by the interests of ship owner as principal and crewing company acting as servant on seaman labor market. Seaman is object in this business process though which principal and servant performing the service pursue their own interests. They treat the seaman interests as secondary and limited to assigning of salary. On the other hand, seaman maximizing behavior i...

  11. Mars Conjunction Crewed Missions With a Reusable Hybrid Architecture

    Science.gov (United States)

    Merrill, Raymond G.; Strange, Nathan J.; Qu, Min; Hatten, Noble

    2015-01-01

    A new crew Mars architecture has been developed that provides many potential benefits for NASA-led human Mars moons and surface missions beginning in the 2030s or 2040s. By using both chemical and electric propulsion systems where they are most beneficial and maintaining as much orbital energy as possible, the Hybrid spaceship that carries crew round trip to Mars is pre-integrated before launch and can be delivered to orbit by a single launch. After check-out on the way to cis-lunar space, it is refueled and can travel round trip to Mars in less than 1100 days, with a minimum of 300 days in Mars vicinity (opportunity dependent). The entire spaceship is recaptured into cis-lunar space and can be reused. The spaceship consists of a habitat for 4 crew attached to the Hybrid propulsion stage which uses long duration electric and chemical in-space propulsion technologies that are in use today. The hybrid architecture's con-ops has no in-space assembly of the crew transfer vehicle and requires only rendezvous of crew in a highly elliptical Earth orbit for arrival at and departure from the spaceship. The crew transfer vehicle does not travel to Mars so it only needs be able to last in space for weeks and re-enter at lunar velocities. The spaceship can be refueled and resupplied for multiple trips to Mars (every other opportunity). The hybrid propulsion stage for crewed transits can also be utilized for cargo delivery to Mars every other opportunity in a reusable manner to pre-deploy infrastructure required for Mars vicinity operations. Finally, the Hybrid architecture provides evolution options for mitigating key long-duration space exploration risks, including crew microgravity and radiation exposure.

  12. Three STS 26 astronauts training in the Crew Compartment trainer

    Science.gov (United States)

    1986-01-01

    Three astronauts named in January 1987 as part of a five-member crew for NASA's first flight since the Challenger accident are shown in a photo session of July 1986. Left to right are Astronauts John M. (Mike) Lounge, Richard O. Covey and David C. Hilmers. Lounge and Hilmers will serve as Mission specialists for the STS 26 flight and Covey will serve as pilot. The three are on the middeck of JSC's one-G Crew Compartment Trainer (CCT).

  13. AMO EXPRESS: A Command and Control Experiment for Crew Autonomy Onboard the International Space Station

    Science.gov (United States)

    Stetson, Howard K.; Haddock, Angie T.; Frank, Jeremy; Cornelius, Randy; Wang, Lui; Garner, Larry

    2015-01-01

    NASA is investigating a range of future human spaceflight missions, including both Mars-distance and Near Earth Object (NEO) targets. Of significant importance for these missions is the balance between crew autonomy and vehicle automation. As distance from Earth results in increasing communication delays, future crews need both the capability and authority to independently make decisions. However, small crews cannot take on all functions performed by ground today, and so vehicles must be more automated to reduce the crew workload for such missions. NASA's Advanced Exploration Systems Program funded Autonomous Mission Operations (AMO) project conducted an autonomous command and control experiment on-board the International Space Station that demonstrated single action intelligent procedures for crew command and control. The target problem was to enable crew initialization of a facility class rack with power and thermal interfaces, and involving core and payload command and telemetry processing, without support from ground controllers. This autonomous operations capability is enabling in scenarios such as initialization of a medical facility to respond to a crew medical emergency, and representative of other spacecraft autonomy challenges. The experiment was conducted using the Expedite the Processing of Experiments for Space Station (EXPRESS) rack 7, which was located in the Port 2 location within the U.S Laboratory onboard the International Space Station (ISS). Activation and deactivation of this facility is time consuming and operationally intensive, requiring coordination of three flight control positions, 47 nominal steps, 57 commands, 276 telemetry checks, and coordination of multiple ISS systems (both core and payload). Utilization of Draper Laboratory's Timeliner software, deployed on-board the ISS within the Command and Control (C&C) computers and the Payload computers, allowed development of the automated procedures specific to ISS without having to certify

  14. 14 CFR 1214.403 - Code of Conduct for the International Space Station Crew.

    Science.gov (United States)

    2010-01-01

    ... Station Crew. 1214.403 Section 1214.403 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION SPACE FLIGHT International Space Station Crew § 1214.403 Code of Conduct for the International Space Station Crew. The Code of Conduct for the International Space Station Crew, which sets...

  15. Design/Development of Spacecraft and Module Crew Compartments

    Science.gov (United States)

    Goodman, Jerry R.

    2010-01-01

    This slide presentation reviews the design and development of crew compartments for spacecraft and for modules. The Crew Compartment or Crew Station is defined as the spacecraft interior and all other areas the crewman interfaces inside the cabin, or may potentially interface.It uses examples from all of the human rated spacecraft. It includes information about the process, significant drivers for the design, habitability, definitions of models, mockups, prototypes and trainers, including pictures of each stage in the development from Apollo, pictures of the space shuttle trainers, and International Space Station trainers. It further reviews the size and shape of the Space Shuttle orbiter crew compartment, and the Apollo command module and the lunar module. It also has a chart which reviews the International Space Station (ISS) internal volume by stage. The placement and use of windows is also discussed. Interestingly according to the table presented, the number 1 rated piece of equipment for recreation was viewing windows. The design of crew positions and restraints, crew translation aids and hardware restraints is shown with views of the restraints and handholds used from the Apollo program through the ISS.

  16. Intercultural crew issues in long-duration spaceflight

    Science.gov (United States)

    Kraft, Norbert O.; Lyons, Terence J.; Binder, Heidi

    2003-01-01

    Before long-duration flights with international crews can be safely undertaken, potential interpersonal difficulties will need to be addressed. Crew performance breakdown has been recognized by the American Institute of Medicine, in scientific literature, and in popular culture. However, few studies of human interaction and performance in confined, isolated environments exist, and the data pertaining to those studies are mostly anecdotal. Many incidents involving crew interpersonal dynamics, those among flight crews, as well as between flight crews and ground controllers, are reported only in non-peer reviewed books and newspapers. Consequently, due to this lack of concrete knowledge, the selection of astronauts and cosmonauts has focused on individual rather than group selection. Additional selection criteria such as interpersonal and communication competence, along with intercultural training, will have a decisive impact on future mission success. Furthermore, industrial psychological research has demonstrated the ability to select a group based on compatibility. With all this in mind, it is essential to conduct further research on heterogeneous, multi-national crews including selection and training for long-duration space missions.

  17. Adaptive coordination and heedfulness make better cockpit crews.

    Science.gov (United States)

    Grote, G; Kolbe, M; Zala-Mezö, E; Bienefeld-Seall, N; Künzle, B

    2010-02-01

    Team coordination during a simulated clean approach performed by 42 civil aviation cockpit crews was analysed. Several hypotheses regarding the adaptive use of implicit and explicit coordination, leadership and heedful interrelating were tested. The results indicate the adaptiveness of coordination to different levels of standardisation and task load and the general importance of explicit coordination for good performance. Leadership seems to be required mainly for work phases with little standardisation. In exploratory lag sequential analyses, heedful behaviour in the seven best and six worst performing crews was examined. The coordination sequences in high performance crews were found to be more succinct and well balanced, indicating that a shared sense of heedfulness is crucial for effectiveness. Theoretical implications for the conceptualisation of adaptive coordination and heedfulness and practical implications for improving crew training are discussed. Statement of Relevance: Analyses of team coordination during a simulated clean approach performed by civil aviation cockpit crews demonstrated the occurrence and effectiveness of adaptive coordination in response to different levels of task load and standardisation. Results also indicated the importance of heedful interrelating, both as a form of coordination and as a way of regulating the adaptiveness of coordination efforts. These findings have important implications for improving crew training, leadership practices and possibly also standard operating procedures.

  18. Development of capacity for measuring ionizing radiation in aircraft crew; Desenvolvimento da capacitacao para efetuar medicoes de radiacao ionizante em tripulacoes de aeronaves

    Energy Technology Data Exchange (ETDEWEB)

    Federico, C.A.; Goncalez, O.L., E-mail: claudiofederico@ieav.cta.b, E-mail: odairl@ieav.cta.b [Centro Tecnico Aeroespacial (CTA/ITA), Sao Jose dos Campos, SP (Brazil). Inst. Tecnologico de Aeronautica; Caldas, L.V.E., E-mail: lcaldas@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    This paper describes the activities performed in a research program of the Institute of Advanced Studies, Brazil, belonging to the Brazilian Air Force, joining to researches from Brazilian Nuclear Energy Commission, in order to bring to Brazil the capacity and acknowledge necessary to the evaluation of dose from ionizing radiation originated in the cosmic radiation and its by products which fall on aircraft crews

  19. Various Lifestyle Factors of Flight Crew Members

    Directory of Open Access Journals (Sweden)

    Marta Bon

    2015-03-01

    Full Text Available Various Lifestyle Factors of Flight Crew Members The main aim of the research was to analyze certain lifestyle factors of flight crew members. This profession has rather high demands relating to body type, basic skills, as well as good mental and physical condition. The sample of respondents included 76 members of the Adria Airways d. d. cabin crew (19.7% men and 80.3% women with the average age of 30.3 years (SD = 9.88, most of them (74.1% finished high school and only one third had a full-time work contract. Using a questionnaire, we investigated the amount of exercise they get during work and in their free time, as well as their health conditions. Results show that in their free time most of the respondents participate in sports, with outdoor sports being the most popular form of exercise (running and walking, hiking, skiing, and swimming. The respondents spend most of their time at work standing up (18.4% and walking (27.6%. Many of them (35% find that they have to maintain postures that are uncomfortable. Most of them experience a combination of all the above. Most (38.2% do sports at least twice a week, and as many as 84.2% 3 to 5 times a week. Only 4% of the respondents participate in sports activities organized by their employer. Most (77.6% believe themselves to be in good health and only 6.6% believe themselves to be often under stress. Relatively many smoke. Among health problems, the highest percentage (46.1% of respondents list fatigue, followed by back pain (34.2% and neck pain (30.3%. Considering the characteristics of this profession, we recommend cabin crew members do aerobic exercise as well as more complex and preventative sport exercises intended to prevent back pain, and also to do more exercises for strength, core stability and flexibility. Různé faktory životního stylu členů letové posádky Hlavním cílem výzkumu bylo analyzovat některé faktory životního stylu členů letových posádek. Tato profese klade

  20. 78 FR 54585 - Safety Zone; Escape to Miami Triathlon, Biscayne Bay, Miami, FL

    Science.gov (United States)

    2013-09-05

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA00 Safety Zone; Escape to Miami Triathlon, Biscayne Bay... during the Publix Escape to Miami Triathlon. The Publix Escape to Miami Triathlon is scheduled to take... of life on navigable waters of the United States during the Publix Escape to Miami Triathlon....

  1. Planning for Crew Exercise for Future Deep Space Mission Scenarios

    Science.gov (United States)

    Moore, Cherice; Ryder, Jeff

    2015-01-01

    Providing the necessary exercise capability to protect crew health for deep space missions will bring new sets of engineering and research challenges. Exercise has been found to be a necessary mitigation for maintaining crew health on-orbit and preparing the crew for return to earth's gravity. Health and exercise data from Apollo, Space Lab, Shuttle, and International Space Station missions have provided insight into crew deconditioning and the types of activities that can minimize the impacts of microgravity on the physiological systems. The hardware systems required to implement exercise can be challenging to incorporate into spaceflight vehicles. Exercise system design requires encompassing the hardware required to provide mission specific anthropometrical movement ranges, desired loads, and frequencies of desired movements as well as the supporting control and monitoring systems, crew and vehicle interfaces, and vibration isolation and stabilization subsystems. The number of crew and operational constraints also contribute to defining the what exercise systems will be needed. All of these features require flight vehicle mass and volume integrated with multiple vehicle systems. The International Space Station exercise hardware requires over 1,800 kg of equipment and over 24 m3 of volume for hardware and crew operational space. Improvements towards providing equivalent or better capabilities with a smaller vehicle impact will facilitate future deep space missions. Deep space missions will require more understanding of the physiological responses to microgravity, understanding appropriate mitigations, designing the exercise systems to provide needed mitigations, and integrating effectively into vehicle design with a focus to support planned mission scenarios. Recognizing and addressing the constraints and challenges can facilitate improved vehicle design and exercise system incorporation.

  2. Extreme hydrodynamic atmospheric loss near the critical thermal escape regime

    CERN Document Server

    Erkaev, N V; Odert, P; Kulikov, Yu N; Kislyakova, K G

    2015-01-01

    By considering martian-like planetary embryos inside the habitable zone of solar-like stars we study the behavior of the hydrodynamic atmospheric escape of hydrogen for small values of the Jeans escape parameter $\\beta < 3$, near the base of the thermosphere, that is defined as a ratio of the gravitational and thermal energy. Our study is based on a 1-D hydrodynamic upper atmosphere model that calculates the volume heating rate in a hydrogen dominated thermosphere due to the absorption of the stellar soft X-ray and extreme ultraviolet (XUV) flux. We find that when the $\\beta$ value near the mesopause/homopause level exceeds a critical value of $\\sim$2.5, there exists a steady hydrodynamic solution with a smooth transition from subsonic to supersonic flow. For a fixed XUV flux, the escape rate of the upper atmosphere is an increasing function of the temperature at the lower boundary. Our model results indicate a crucial enhancement of the atmospheric escape rate, when the Jeans escape parameter $\\beta$ decr...

  3. Single-File Escape of Colloidal Particles from Microfluidic Channels

    Science.gov (United States)

    Locatelli, Emanuele; Pierno, Matteo; Baldovin, Fulvio; Orlandini, Enzo; Tan, Yizhou; Pagliara, Stefano

    2016-07-01

    Single-file diffusion is a ubiquitous physical process exploited by living and synthetic systems to exchange molecules with their environment. It is paramount to quantify the escape time needed for single files of particles to exit from constraining synthetic channels and biological pores. This quantity depends on complex cooperative effects, whose predominance can only be established through a strict comparison between theory and experiments. By using colloidal particles, optical manipulation, microfluidics, digital microscopy, and theoretical analysis we uncover the self-similar character of the escape process and provide closed-formula evaluations of the escape time. We find that the escape time scales inversely with the diffusion coefficient of the last particle to leave the channel. Importantly, we find that at the investigated microscale, bias forces as tiny as 10-15 N determine the magnitude of the escape time by drastically reducing interparticle collisions. Our findings provide crucial guidelines to optimize the design of micro- and nanodevices for a variety of applications including drug delivery, particle filtering, and transport in geometrical constrictions.

  4. Escape dynamics in a binary system of interacting galaxies

    CERN Document Server

    Zotos, Euaggelos E

    2016-01-01

    The escape dynamics in an analytical gravitational model which describes the motion of stars in a binary system of interacting dwarf spheroidal galaxies is investigated in detail. We conduct a numerical analysis distinguishing between regular and chaotic orbits as well as between trapped and escaping orbits, considering only unbounded motion for several energy levels. In order to distinguish safely and with certainty between ordered and chaotic motion, we apply the Smaller ALingment Index (SALI) method. It is of particular interest to locate the escape basins through the openings around the collinear Lagrangian points $L_1$ and $L_2$ and relate them with the corresponding spatial distribution of the escape times of the orbits. Our exploration takes place both in the configuration $(x,y)$ and in the phase $(x,\\dot{x})$ space in order to elucidate the escape process as well as the overall orbital properties of the galactic system. Our numerical analysis reveals the strong dependence of the properties of the con...

  5. Enhancing Endosomal Escape for Intracellular Delivery of Macromolecular Biologic Therapeutics.

    Science.gov (United States)

    Lönn, Peter; Kacsinta, Apollo D; Cui, Xian-Shu; Hamil, Alexander S; Kaulich, Manuel; Gogoi, Khirud; Dowdy, Steven F

    2016-09-08

    Bioactive macromolecular peptides and oligonucleotides have significant therapeutic potential. However, due to their size, they have no ability to enter the cytoplasm of cells. Peptide/Protein transduction domains (PTDs), also called cell-penetrating peptides (CPPs), can promote uptake of macromolecules via endocytosis. However, overcoming the rate-limiting step of endosomal escape into the cytoplasm remains a major challenge. Hydrophobic amino acid R groups are known to play a vital role in viral escape from endosomes. Here we utilize a real-time, quantitative live cell split-GFP fluorescence complementation phenotypic assay to systematically analyze and optimize a series of synthetic endosomal escape domains (EEDs). By conjugating EEDs to a TAT-PTD/CPP spilt-GFP peptide complementation assay, we were able to quantitatively measure endosomal escape into the cytoplasm of live cells via restoration of GFP fluorescence by intracellular molecular complementation. We found that EEDs containing two aromatic indole rings or one indole ring and two aromatic phenyl groups at a fixed distance of six polyethylene glycol (PEG) units from the TAT-PTD-cargo significantly enhanced cytoplasmic delivery in the absence of cytotoxicity. EEDs address the critical rate-limiting step of endosomal escape in delivery of macromolecular biologic peptide, protein and siRNA therapeutics into cells.

  6. Immunosuppressive cells in tumor immune escape and metastasis.

    Science.gov (United States)

    Liu, Yang; Cao, Xuetao

    2016-05-01

    Tumor immune escape and the initiation of metastasis are critical steps in malignant progression of tumors and have been implicated in the failure of some clinical cancer immunotherapy. Tumors develop numerous strategies to escape immune surveillance or metastasize: Tumors not only modulate the recruitment and expansion of immunosuppressive cell populations to develop the tumor microenvironment or pre-metastatic niche but also switch the phenotype and function of normal immune cells from a potentially tumor-reactive state to a tumor-promoting state. Immunosuppressive cells facilitate tumor immune escape by inhibiting antitumor immune responses and furthermore promote tumor metastasis by inducing immunosuppression, promoting tumor cell invasion and intravasation, establishing a pre-metastatic niche, facilitating epithelial-mesenchymal transition, and inducing angiogenesis at primary tumor or metastatic sites. Numerous translational studies indicate that it is possible to inhibit tumor immune escape and prevent tumor metastasis by blocking immunosuppressive cells and eliminating immunosuppressive mechanisms that are induced by either immunosuppressive cells or tumor cells. Furthermore, many clinical trials targeting immunosuppressive cells have also achieved good outcome. In this review, we focus on the underlying mechanisms of immunosuppressive cells in promoting tumor immune escape and metastasis, discuss our current understanding of the interactions between immunosuppressive cells and tumor cells in the tumor microenvironment, and suggest future research directions as well as potential clinical strategies in cancer immunotherapy.

  7. Enhancing endosomal escape for nanoparticle mediated siRNA delivery

    Science.gov (United States)

    Ma, Da

    2014-05-01

    Gene therapy with siRNA is a promising biotechnology to treat cancer and other diseases. To realize siRNA-based gene therapy, a safe and efficient delivery method is essential. Nanoparticle mediated siRNA delivery is of great importance to overcome biological barriers for systemic delivery in vivo. Based on recent discoveries, endosomal escape is a critical biological barrier to be overcome for siRNA delivery. This feature article focuses on endosomal escape strategies used for nanoparticle mediated siRNA delivery, including cationic polymers, pH sensitive polymers, calcium phosphate, and cell penetrating peptides. Work has been done to develop different endosomal escape strategies based on nanoparticle types, administration routes, and target organ/cell types. Also, enhancement of endosomal escape has been considered along with other aspects of siRNA delivery to ensure target specific accumulation, high cell uptake, and low toxicity. By enhancing endosomal escape and overcoming other biological barriers, great progress has been achieved in nanoparticle mediated siRNA delivery.

  8. Application of Human-Autonomy Teaming (HAT) Patterns to Reduced Crew Operations (RCO)

    Science.gov (United States)

    Shively, R. Jay; Brandt, Summer L.; Lachter, Joel; Matessa, Mike; Sadler, Garrett; Battiste, Henri

    2016-01-01

    As part of the Air Force - NASA Bi-Annual Research Council Meeting, slides will be presented on recent Reduced Crew Operations (RCO) work. Unmanned aerial systems, robotics, advanced cockpits, and air traffic management are all examples of domains that are seeing dramatic increases in automation. While automation may take on some tasks previously performed by humans, humans will still be required, for the foreseeable future, to remain in the system. The collaboration with humans and these increasingly autonomous systems will begin to resemble cooperation between teammates, rather than simple task allocation. It is critical to understand this human-autonomy teaming (HAT) to optimize these systems in the future. One methodology to understand HAT is by identifying recurring patterns of HAT that have similar characteristics and solutions. A methodology for identifying HAT patterns to an advanced cockpit project is discussed.

  9. STS-47 crew and backups at MSFC's Payload Crew Training Complex

    Science.gov (United States)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Spacelab Japan (SLJ) crewmembers and backup payload specialists stand outside SLJ module mockup at the Payload Crew Training Complex at Marshall SpaceFlight Center (MSFC) in Huntsville, Alabama. From left to right are Payload Specialist Mamoru Mohri, backup Payload Specialist Takao Doi, backup Payload Specialist Chiaki Naito-Mukai, Mission Specialist (MS) Mae C. Jemison, MS N. Jan Davis, backup Payload Specialist Stan Koszelak, and MS and Payload Commander (PLC) Mark C. Lee. The MSFC-managed mission is a joint venture in space-based research between the United States and Japan. Mohri, Doi, and Mukai represent Japan's National Space Development Agency (NASDA). View provided with alternate number 92P-142.

  10. Escape rate and diffusion of a Stochastically Driven particle

    Science.gov (United States)

    Piscitelli, Antonio; Pica Ciamarra, Massimo

    2017-01-01

    The dynamical properties of a tracer repeatedly colliding with heat bath particles can be described within a Langevin framework provided that the tracer is more massive than the bath particles, and that the collisions are frequent. Here we consider the escape of a particle from a potential well, and the diffusion coefficient in a periodic potential, without making these assumptions. We have thus investigated the dynamical properties of a Stochastically Driven particle that moves under the influence of the confining potential in between successive collisions with the heat bath. In the overdamped limit, both the escape rate and the diffusion coefficient coincide with those of a Langevin particle. Conversely, in the underdamped limit the two dynamics have a different temperature dependence. In particular, at low temperature the Stochastically Driven particle has a smaller escape rate, but a larger diffusion coefficient. PMID:28120904

  11. Escape probability of the super-Penrose process

    CERN Document Server

    Ogasawara, Kota; Miyamoto, Umpei; Igata, Takahisa; Patil, Mandar

    2016-01-01

    We consider a head-on collision of two massive particles that move in the equatorial plane of an extremal Kerr black hole, which results in the production of two massless particles. Focusing a typical case, where both of the colliding particles have zero angular momenta, we show that a massless particle produced in such a collision can escape to infinity with arbitrarily large energy in the near-horizon limit of the collision point. Furthermore, if we assume that the emission of the produced massless particles is isotropic in the center-of-mass frame but confined to the equatorial plane, the escape probability of the produced massless particle approaches $5/12$ and almost all escaping massless particles have arbitrarily large energy at infinity and an impact parameter approaching $2M$.

  12. Crew Roles and Interactions in Scientific Space Exploration

    Science.gov (United States)

    Love, Stanley G.; Bleacher, Jacob E.

    2013-01-01

    Future piloted space exploration missions will focus more on science than engineering, a change which will challenge existing concepts for flight crew tasking and demand that participants with contrasting skills, values, and backgrounds learn to cooperate as equals. In terrestrial space flight analogs such as Desert Research And Technology Studies, engineers, pilots, and scientists can practice working together, taking advantage of the full breadth of all team members training to produce harmonious, effective missions that maximize the time and attention the crew can devote to science. This paper presents, in a format usable as a reference by participants in the field, a successfully tested crew interaction model for such missions. The model builds upon the basic framework of a scientific field expedition by adding proven concepts from aviation and human spaceflight, including expeditionary behavior and cockpit resource management, cooperative crew tasking and adaptive leadership and followership, formal techniques for radio communication, and increased attention to operational considerations. The crews of future spaceflight analogs can use this model to demonstrate effective techniques, learn from each other, develop positive working relationships, and make their expeditions more successful, even if they have limited time to train together beforehand. This model can also inform the preparation and execution of actual future spaceflights.

  13. Operational considerations for a crewed nuclear powered space transportation vehicle

    Science.gov (United States)

    Borrer, Jerry L.; Hoffman, Stephen J.

    1993-01-01

    Applying nuclear propulsion technology to human space travel will require new approaches to conducting human operations in space. Due to the remoteness of these types of missions, the crew and their vehicle must be capable of operating independent from Earth-based support. This paper discusses current operational studies which address methods for performing these types of remote and autonomous missions. Methods of managing the hazards to humans who will operate these high-energy nuclear-powered transportation vehicles also is reviewed. Crew training for both normal and contingency operations is considered. Options are evaluated on how best to train crews to operate and maintain the systems associated with a nuclear engine. Methods of maintaining crew proficiency during the long months of space travel are discussed. Vehicle health maintenance also will be a primary concern during these long missions. A discussion is presented on how on-board vehicle health maintenance systems will monitor system trends, identified system weaknesses, and either isolate critical failures or provide the crew with adequate warning of impending problems.

  14. Crew roles and interactions in scientific space exploration

    Science.gov (United States)

    Love, Stanley G.; Bleacher, Jacob E.

    2013-10-01

    Future piloted space exploration missions will focus more on science than engineering, a change which will challenge existing concepts for flight crew tasking and demand that participants with contrasting skills, values, and backgrounds learn to cooperate as equals. In terrestrial space flight analogs such as Desert Research And Technology Studies, engineers, pilots, and scientists can practice working together, taking advantage of the full breadth of all team members' training to produce harmonious, effective missions that maximize the time and attention the crew can devote to science. This paper presents, in a format usable as a reference by participants in the field, a successfully tested crew interaction model for such missions. The model builds upon the basic framework of a scientific field expedition by adding proven concepts from aviation and human space flight, including expeditionary behavior and cockpit resource management, cooperative crew tasking and adaptive leadership and followership, formal techniques for radio communication, and increased attention to operational considerations. The crews of future space flight analogs can use this model to demonstrate effective techniques, learn from each other, develop positive working relationships, and make their expeditions more successful, even if they have limited time to train together beforehand. This model can also inform the preparation and execution of actual future space flights.

  15. Escape of protists in predator-generated feeding currents

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik

    2002-01-01

    The ciliate Strobilidium sp. and 2 flagellates, Chrysochromulina simplex and Gymnodinium sp., were exposed to predator-generated feeding currents, and their escape responses were quantified using 2- and 3-dimensional video techniques. All 3 studied organisms responded by escaping at a defined...... of Strobilidium sp. to the copepod Temora longicornis. The predicted reaction distance fit closely that measured, When the flagellates were exposed to the flow field of the ciliate Uronema filificum, they both responded up-stream to the feeding current. From the distance at which the flagellates responded...

  16. Escape probability based routing for ad hoc networks

    Institute of Scientific and Technical Information of China (English)

    Zhang Xuanping; Qin Zheng; Li Xin

    2006-01-01

    Routes in an ad hoc network may fail frequently because of node mobility. Stability therefore can be an important element in the design of routing protocols. The node escape probability is introduced to estimate the lifetime and stability of link between neighboring nodes and the escape probability based routing (EPBR) scheme to discover stable routes is proposed. Simulation results show that the EPBR can discover stable routes to reduce the number of route rediscovery, and is applicable for the situation that has highly dynamic network topology with broad area of communication.

  17. Rapid endosomal escape of prickly nanodiamonds: implications for gene delivery

    Science.gov (United States)

    Chu, Zhiqin; Miu, Kaikei; Lung, Pingsai; Zhang, Silu; Zhao, Saisai; Chang, Huan-Cheng; Lin, Ge; Li, Quan

    2015-06-01

    The prickly nanodiamonds easily entered cells via endocytosis followed by unique intracellular translocation characteristics—quick endosomal escape followed by stable residence in cytoplasm. Endosomal membrane rupturing is identified as the major route of nanodiamonds’ escaping the vesicle confinement and to the cytoplasm. Little cytotoxicity is observed to associate with the nanodiamonds’ cytosolic release. Such features enable its application for gene delivery, which requires both effective cellular uptake and cytosolic release of the gene. Taking green fluorescent protein gene as an example, we demonstrate the successful cytosolic delivery and expression of such a gene using the prickly nanodiamonds as carrier.

  18. Occupational cosmic radiation exposure and cancer in airline cabin crew.

    Energy Technology Data Exchange (ETDEWEB)

    Kojo, K.

    2013-03-15

    Cosmic radiation dose rates are considerably higher at cruising altitudes of airplanes than at ground level. Previous studies have found increased risk of certain cancers among aircraft cabin crew, but the results are not consistent across different studies. Despite individual cosmic radiation exposure assessment is important for evaluating the relation between cosmic radiation exposure and cancer risk, only few previous studies have tried to develop an exposure assessment method. The evidence for adverse health effects in aircrews due to ionizing radiation is inconclusive because quantitative dose estimates have not been used. No information on possible confounders has been collected. For an occupational group with an increased risk of certain cancers it is very important to assess if the risk is related to occupational exposure. The goal of this thesis was to develop two separate retrospective exposure assessment methods for occupational exposure to cosmic radiation. The methods included the assessment based on survey on flight histories and based on company flight timetables. Another goal was to describe the cancer incidence among aircraft cabin crew with a large cohort in four Nordic countries, i.e., Finland, Iceland, Norway, and Sweden. Also the contribution of occupational as well as non-occupational factors to breast and skin cancer risk among the cabin crew was studied with case-control studies. Using the survey method of cosmic radiation exposure assessment, the median annual radiation dose of Finnish airline cabin crew was 0.6 milliSievert (mSv) in the 1960s, 3.3 mSv in the 1970s, and 3.6 mSv in the 1980s. With the flight timetable method, the annual radiation dose increased with time being 0.7 mSv in the 1960 and 2.1 mSv in the 1995. With the survey method, the median career dose was 27.9 mSv and with the timetable method 20.8 mSv. These methods provide improved means for individual cosmic radiation exposure assessment compared to studies where cruder

  19. Crew Exploration Vehicle (CEV) (Orion) Occupant Protection. Part 1; Appendices

    Science.gov (United States)

    Currie-Gregg, Nancy J.; Gernhardt, Michael L.; Lawrence, Charles; Somers, Jeffrey T.

    2016-01-01

    Dr. Nancy J. Currie, of the NASA Engineering and Safety Center (NESC), Chief Engineer at Johnson Space Center (JSC), requested an assessment of the Crew Exploration Vehicle (CEV) occupant protection as a result of issues identified by the Constellation Program and Orion Project. The NESC, in collaboration with the Human Research Program (HRP), investigated new methods associated with occupant protection for the Crew Exploration Vehicle (CEV), known as Orion. The primary objective of this assessment was to investigate new methods associated with occupant protection for the CEV, known as Orion, that would ensure the design provided minimal risk to the crew during nominal and contingency landings in an acceptable set of environmental and spacecraft failure conditions. This documents contains the appendices to the NESC assessment report. NASA/TM-2013-217380, Application of the Brinkley Dynamic Response Criterion to Spacecraft Transient Dynamic Events supersedes this document.

  20. Autologous HIV-1 neutralizing antibodies: emergence of neutralization-resistant escape virus and subsequent development of escape virus neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Nielsen, C; Hansen, J E;

    1992-01-01

    The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development of ...... escape virus may be part of the explanation of the apparent failure of the immune system to control HIV infection.......The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development...... of neutralizing antibodies to the primary virus isolates was detected 13-45 weeks after seroconversion. Emergence of escape virus with reduced sensitivity to neutralization by autologous sera was demonstrated. The patients subsequently developed neutralizing antibodies against the escape virus but after a delay...

  1. Space biology initiative program definition review. Trade study 1: Automation costs versus crew utilization

    Science.gov (United States)

    Jackson, L. Neal; Crenshaw, John, Sr.; Hambright, R. N.; Nedungadi, A.; Mcfayden, G. M.; Tsuchida, M. S.

    1989-01-01

    A significant emphasis upon automation within the Space Biology Initiative hardware appears justified in order to conserve crew labor and crew training effort. Two generic forms of automation were identified: automation of data and information handling and decision making, and the automation of material handling, transfer, and processing. The use of automatic data acquisition, expert systems, robots, and machine vision will increase the volume of experiments and quality of results. The automation described may also influence efforts to miniaturize and modularize the large array of SBI hardware identified to date. The cost and benefit model developed appears to be a useful guideline for SBI equipment specifiers and designers. Additional refinements would enhance the validity of the model. Two NASA automation pilot programs, 'The Principal Investigator in a Box' and 'Rack Mounted Robots' were investigated and found to be quite appropriate for adaptation to the SBI program. There are other in-house NASA efforts that provide technology that may be appropriate for the SBI program. Important data is believed to exist in advanced medical labs throughout the U.S., Japan, and Europe. The information and data processing in medical analysis equipment is highly automated and future trends reveal continued progress in this area. However, automation of material handling and processing has progressed in a limited manner because the medical labs are not affected by the power and space constraints that Space Station medical equipment is faced with. Therefore, NASA's major emphasis in automation will require a lead effort in the automation of material handling to achieve optimal crew utilization.

  2. NASA Ares I Crew Launch Vehicle Upper Stage Overview

    Science.gov (United States)

    Davis, Daniel J.

    2008-01-01

    By incorporating rigorous engineering practices, innovative manufacturing processes and test techniques, a unique multi-center government/contractor partnership, and a clean-sheet design developed around the primary requirements for the International Space Station (ISS) and Lunar missions, the Upper Stage Element of NASA's Crew Launch Vehicle (CLV), the "Ares I," is a vital part of the Constellation Program's transportation system. Constellation's exploration missions will include Ares I and Ares V launch vehicles required to place crew and cargo in low-Earth orbit (LEO), crew and cargo transportation systems required for human space travel, and transportation systems and scientific equipment required for human exploration of the Moon and Mars. Early Ares I configurations will support ISS re-supply missions. A self-supporting cylindrical structure, the Ares I Upper Stage will be approximately 84' long and 18' in diameter. The Upper Stage Element is being designed for increased supportability and increased reliability to meet human-rating requirements imposed by NASA standards. The design also incorporates state-of-the-art materials, hardware, design, and integrated logistics planning, thus facilitating a supportable, reliable, and operable system. With NASA retiring the Space Shuttle fleet in 2010, the success of the Ares I Project is essential to America's continued leadership in space. The first Ares I test flight, called Ares 1-X, is scheduled for 2009. Subsequent test flights will continue thereafter, with the first crewed flight of the Crew Exploration Vehicle (CEV), "Orion," planned for no later than 2015. Crew transportation to the ISS will follow within the same decade, and the first Lunar excursion is scheduled for the 2020 timeframe.

  3. STS-103 crew practice emergency egress in the slidewire basket

    Science.gov (United States)

    1999-01-01

    In the slidewire basket on Launch Pad 39B, STS-103 Mission Specialist C. Michael Foale (Ph.D.) gets ready to pull the lever, which will release the basket. With Foale are fellow crew members Mission Specialists Claude Nicollier of Switzerland and John M. Grunsfeld (Ph.D.). The baskets are part of the emergency egress system for persons in the Shuttle vehicle or on the Rotating Service Structure. Seven slidewires extend from the orbiter access arm, with a netted, flatbottom basket suspended from each wire. The STS-103 crew are taking part in Terminal Countdown Demonstration Test (TCDT) activities in preparation for launch. The other crew members taking part are Commander Curtis L. Brown Jr., Pilot Scott J. Kelly, and Mission Specialists Steven L. Smith, and Jean-Frangois Clervoy of France. Clervoy and Nicollier are with the European Space Agency. The TCDT provides the crew with the emergency egress training, opportunities to inspect their mission payloads in the orbiter's payload bay, and simulated countdown exercises. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  4. Mechanical properties of the cuticles of three cockroach species that differ in their wind-evoked escape behavior

    Directory of Open Access Journals (Sweden)

    Andrew J. Clark

    2014-07-01

    Full Text Available The structural and material properties of insect cuticle remain largely unexplored, even though they comprise the majority (approximately 80% of animals. Insect cuticle serves many functions, including protection against predatory attacks, which is especially beneficial to species failing to employ effective running escape responses. Despite recent advances in our understanding of insect escape behaviors and the biomechanics of insect cuticle, there are limited studies on the protective qualities of cuticle to extreme mechanical stresses and strains imposed by predatory attacks, and how these qualities vary between species employing different escape responses. Blattarians (cockroaches provide an appropriate model system for such studies. Wind-evoked running escape responses are strong in Periplaneta americana, weak in Blaberus craniifer and absent in Gromphodorhina portentosa, putting the latter two species at greater risk of being struck by a predator. We hypothesized that the exoskeletons in these two larger species could provide more protection from predatory strikes relative to the exoskeleton of P. americana. We quantified the protective qualities of the exoskeletons by measuring the puncture resistance, tensile strength, strain energy storage, and peak strain in fresh samples of thoracic and abdominal cuticles from these three species. We found a continuum in puncture resistance, tensile strength, and strain energy storage between the three species, which were greatest in G. portentosa, moderate in B. craniifer, and smallest in P. americana. Histological measurements of total cuticle thickness followed this same pattern. However, peak strain followed a different trend between species. The comparisons in the material properties drawn between the cuticles of G. portentosa, B. craniifer, and P. americana demonstrate parallels between cuticular biomechanics and predator running escape responses.

  5. Adaptive Attitude Control of the Crew Launch Vehicle

    Science.gov (United States)

    Muse, Jonathan

    2010-01-01

    An H(sub infinity)-NMA architecture for the Crew Launch Vehicle was developed in a state feedback setting. The minimal complexity adaptive law was shown to improve base line performance relative to a performance metric based on Crew Launch Vehicle design requirements for all most all of the Worst-on-Worst dispersion cases. The adaptive law was able to maintain stability for some dispersions that are unstable with the nominal control law. Due to the nature of the H(sub infinity)-NMA architecture, the augmented adaptive control signal has low bandwidth which is a great benefit for a manned launch vehicle.

  6. The evolution of Crew Resource Management training in commercial aviation

    Science.gov (United States)

    Helmreich, R. L.; Merritt, A. C.; Wilhelm, J. A.

    1999-01-01

    In this study, we describe changes in the nature of Crew Resource Management (CRM) training in commercial aviation, including its shift from cockpit to crew resource management. Validation of the impact of CRM is discussed. Limitations of CRM, including lack of cross-cultural generality are considered. An overarching framework that stresses error management to increase acceptance of CRM concepts is presented. The error management approach defines behavioral strategies taught in CRM as error countermeasures that are employed to avoid error, to trap errors committed, and to mitigate the consequences of error.

  7. Skylab 3 crew during training in Orbital Workshop trainer

    Science.gov (United States)

    1973-01-01

    The three prime crewmen of the Skylab 3 mission check over flight data during a training session in the crew quarters of the Orbital Workshop (OWS) trainer in the Mission Simulation and Training Facility at JSC. They are from left to right, Scientist-Astronaut Owen K. Garriott, science pilot; and Astronauts Alan L. bean, commander, and Jack R. Lousma, pilot (28419); Skylab 3 crew work with Inflight Medical Support System (IMSS) resupply container atop the food table in the OWS. From left to right are Garriott, Lousma and Bean (28420).

  8. Mutations That Alter Use of Hepatitis C Virus Cell Entry Factors Mediate Escape From Neutralizing Antibodies

    Science.gov (United States)

    FAUVELLE, CATHERINE; ZAHID, MUHAMMAD NAUMAN; TUREK, MARINE; HEYDMANN, LAURA; CURY, KARINE; HAYER, JULIETTE; COMBET, CHRISTOPHE; COSSET, FRANÇOIS–LOÏC; PIETSCHMANN, THOMAS; HIET, MARIE–SOPHIE; BARTENSCHLAGER, RALF; HABERSETZER, FRANÇOIS; DOFFOËL, MICHEL; KECK, ZHEN–YONG; FOUNG, STEVEN K. H.; ZEISEL, MIRJAM B.; STOLL–KELLER, FRANÇOISE; BAUMERT, THOMAS F.

    2017-01-01

    BACKGROUND & AIMS The development of vaccines and other strategies to prevent hepatitis C virus (HCV) infection is limited by rapid viral evasion. HCV entry is the first step of infection; this process involves several viral and host factors and is targeted by host-neutralizing responses. Although the roles of host factors in HCV entry have been well characterized, their involvement in evasion of immune responses is poorly understood. We used acute infection of liver graft as a model to investigate the molecular mechanisms of viral evasion. METHODS We studied factors that contribute to evasion of host immune responses using patient-derived antibodies, HCV pseudoparticles, and cell culture–derived HCV that express viral envelopes from patients who have undergone liver transplantation. These viruses were used to infect hepatoma cell lines that express different levels of HCV entry factors. RESULTS By using reverse genetic analyses, we identified altered use of host-cell entry factors as a mechanism by which HCV evades host immune responses. Mutations that alter use of the CD81 receptor also allowed the virus to escape neutralizing antibodies. Kinetic studies showed that these mutations affect virus–antibody interactions during postbinding steps of the HCV entry process. Functional studies with a large panel of patient-derived antibodies showed that this mechanism mediates viral escape, leading to persistent infection in general. CONCLUSIONS We identified a mechanism by which HCV evades host immune responses, in which use of cell entry factors evolves with escape from neutralizing antibodies. These findings advance our understanding of the pathogenesis of HCV infection and might be used to develop antiviral strategies and vaccines. PMID:22503792

  9. Spatial and Nonspatial Escape Strategies in the Barnes Maze

    Science.gov (United States)

    Harrison, Fiona E.; Reiserer, Randall S.; Tomarken, Andrew J.; McDonald, Michael P.

    2006-01-01

    The Barnes maze is a spatial memory task that requires subjects to learn the position of a hole that can be used to escape the brightly lit, open surface of the maze. Two experiments assessed the relative importance of spatial (extra-maze) versus proximal visible cues in solving the maze. In Experiment 1, four groups of mice were trained either…

  10. Entrapment and escape of liquid lubricant in metal forming

    DEFF Research Database (Denmark)

    Bech, Jakob Ilsted; Bay, Niels; Eriksen, Morten

    1999-01-01

    with Varying viscosity, speed, reduction, workpiece material, back tension and friction. The mechanisms are influenced by all these parameters in an explicable way. Theoretical models of the escape mechanisms are established combining continuum mechanic analyses of the die pressure distribution with a fluid...

  11. Enuresis Control through Fading, Escape, and Avoidance Training.

    Science.gov (United States)

    Hansen, Gordon D.

    1979-01-01

    A twin signal device that provides both escape and avoidance conditioning in enuresis control was documented with case studies of two enuretic children (eight and nine years old). In addition, a technique of fading as an adjunct to the process was utilized with one subject. (Author/SBH)

  12. Brain size as a driver of avian escape strategy.

    Science.gov (United States)

    Samia, Diogo S M; Pape Møller, Anders; Blumstein, Daniel T

    2015-07-03

    After detecting an approaching predator, animals make a decision when to flee. Prey will initiate flight soon after detecting a predator so as to minimize attentional costs related to on-going monitoring of the whereabouts of the predator. Such costs may compete with foraging and other maintenance activities and hence be larger than the costs of immediate flight. The drivers of interspecific variation in escape strategy are poorly known. Here we investigated the morphological, life history and natural history traits that correlate with variation in avian escape strategy across a sample of 96 species of birds. Brain mass, body size, habitat structure and group size were the main predictors of escape strategy. The direction of the effect of these traits was consistent with selection for a reduction of monitoring costs. Therefore, attentional costs depend on relative brain size, which determines the ability to monitor the whereabouts of potential predators and the difficulty of this task as reflected by habitat and social complexity. Thus brain size, and the cognitive functions associated with it, constitute a general framework for explaining the effects of body size, habitat structure and sociality identified as determinants of avian escape strategy.

  13. The spectrum of Cosmic Rays escaping from relativistic shocks

    CERN Document Server

    Katz, Boaz; Waxman, Eli

    2010-01-01

    We derive expressions for the time integrated spectrum of Cosmic Rays (CRs) that are accelerated in a decelerating relativistic shock wave and escape ahead of the shock. It is assumed that at any given time the CRs have a power law form, carry a constant fraction of the energy E_tot of the shocked plasma, and escape continuously at the maximal energy attainable. The spectrum of escaping particles is highly sensitive to the instantaneous spectral index due to the fact that the minimal energy, E_min ~ \\Gamma^2 m_pc^2 where \\Gamma is the shock Lorentz factor, changes with time. In particular, the escaping spectrum may be considerably harder than the canonical N(E)\\propto E^-2 spectrum. For a shock expanding into a plasma of density n, a spectral break is expected at the maximal energy attainable at the transition to non relativistic velocities, E ~ 10^19 (\\epsilon_B/0.1)(n/1 cm^-3)^(1/6)(E_tot/10^51 erg)^(1/3) eV where \\epsilon_B is the fraction of the energy flux carried by the magnetic field. If ultra-high ene...

  14. Entropy, Lyapunov Exponents and Escape Rates in Open Systems

    CERN Document Server

    Demers, Mark; Young, Lai-Sang

    2011-01-01

    We study the relation between escape rates and pressure in general dynamical systems with holes, where pressure is defined to be the difference between entropy and the sum of positive Lyapunov exponents. Central to the discussion is the formulation of a class of invariant measures supported on the survivor set over which we take the supremum to measure the pressure. Upper bounds for escape rates are proved for general diffeomorphisms of manifolds, possibly with singularities, for arbitrary holes and natural initial distributions including Lebesgue and SRB measures. Lower bounds do not hold in such generality, but for systems admitting Markov tower extensions with spectral gaps, we prove the equality of the escape rate with the absolute value of the pressure and the existence of an invariant measure realizing the escape rate, i.e. we prove a full variational principle. As an application of our results, we prove a variational principle for the billiard map associated with a planar Lorentz gas of finite horizon ...

  15. Escaping Embarrassment: Face-Work in the Rap Cipher

    Science.gov (United States)

    Lee, Jooyoung

    2009-01-01

    How do individuals escape embarrassing moments in interaction? Drawing from ethnographic fieldwork, in-depth interviews, and video recordings of weekly street corner ciphers (impromptu rap sessions), this paper expands Goffman's theory of defensive and protective face-work. The findings reveal formulaic and indirect dimensions of face-work. First,…

  16. Purinergic inhibition of ENaC produces aldosterone escape.

    Science.gov (United States)

    Stockand, James D; Mironova, Elena; Bugaj, Vladislav; Rieg, Timo; Insel, Paul A; Vallon, Volker; Peti-Peterdi, Janos; Pochynyuk, Oleh

    2010-11-01

    The mechanisms underlying "aldosterone escape," which refers to the excretion of sodium (Na(+)) during high Na(+) intake despite inappropriately increased levels of mineralocorticoids, are incompletely understood. Because local purinergic tone in the aldosterone-sensitive distal nephron downregulates epithelial Na(+) channel (ENaC) activity, we tested whether this mechanism mediates aldosterone escape. Here, urinary ATP concentration increased with dietary Na(+) intake in mice. Physiologic concentrations of ATP decreased ENaC activity in a dosage-dependent manner. P2Y(2)(-/-) mice, which lack the purinergic receptor, had significantly less increased Na(+) excretion than wild-type mice in response to high-Na(+) intake. Exogenous deoxycorticosterone acetate and deletion of the P2Y(2) receptor each modestly increased the resistance of ENaC to changes in Na(+) intake; together, they markedly increased resistance. Under the latter condition, ENaC could not respond to changes in Na(+) intake. In contrast, as a result of aldosterone escape, wild-type mice had increased Na(+) excretion in response to high-Na(+) intake regardless of the presence of high deoxycorticosterone acetate. These data suggest that control of ENaC by purinergic signaling is necessary for aldosterone escape.

  17. The Dutch approach to the escape from large compartments

    NARCIS (Netherlands)

    Janse, E.W.; Leur, P.H.E. van de

    1999-01-01

    In the Netherlands, the building regulations have no design mies for large fire compartments (over 1000 m2). With respect to the ability of people to escape from a fire in such large spaces, the Centre for Fire Research of TNO Building and Construction Research has developed a guideline that integra

  18. Plasma-induced Escape and Alterations of Planetary Atmospheres

    Science.gov (United States)

    Johnson, R. E.; Tucker, O. J.; Ewrin, J.; Cassidy, T. A.; Leblanc, F.

    2009-12-01

    The atmospheres of planets and planetary satellites are typically imbedded in space plasmas. Depending on the interaction with the induced or intrinsic fields energetic ions can have access to the thermosphere and the corona affecting their composition and thermal structure and causing loss to space. These processes are often lumped together as ‘atmospheric sputtering’ (Johnson 1994). In this talk I will review the results of simulations of the plasma bombardment at a number of solar system bodies and use those data to describe the effect on the upper atmosphere and on escape. Of considerable recent interest is the modeling of escape from Titan. Prior to Cassini’s tour of the Saturnian system, plasma-induced escape was suggested to be the dominant loss process, but recent models of enhanced thermal escape, often referred to as ‘slow hydrodynamic’ escape, have been suggested to lead to much larger Titan atmospheric loss rates (Strobel 2008; Cui et al. 2008). Such a process has been suggested to be active at some point in time on a number of solar system bodies. I will present hybrid fluid/ kinetic models of the upper atmosphere of certain bodies in order to test both the plasma-induced and thermal escape processes. Preliminary results suggest that the loss rates estimated using the ‘slow hydrodynamic’ escape process can be orders of magnitude too large. The implications for Mars, Titan and Pluto will be discussed. Background for this talk is contained in the following papers (Johnson 2004; 2009; Chaufray et al. 2007; Johnson et al. 2008; 2009; Tucker and Johnson 2009). References: Chaufray, J.Y., R. Modolo, F. Leblanc, G. Chanteur, R.E. Johnson, and J.G. Luhmann, Mars Solar Wind interaction: formation of the Martian corona and atmosphric loss to space, JGR 112, E09009, doi:10.1029/2007JE002915 (2007) Cui, J., Yelle, R. V., Volk, K. Distribution and escape of molecular hydrogen in Titan's thermosphere and exosphere. J. Geophys. Res. 113, doi:10

  19. Escape chambers in the German coal mining industry. Fluchtkammern im deutschen Steinkohlenbergbau

    Energy Technology Data Exchange (ETDEWEB)

    Kock, F.J.; Langer, G. (Bergbau-Forschung G.m.b.H. - Forschungsinstitut des Steinkohlenbergbauvereins, Essen (Germany, F.R.). Hauptstelle fuer das Grubenrettungswesen); Velsen-Zerweck, R. von; Boettcher, K. (Bergbau AG Westfalen, Dortmund (Germany, F.R.). Hauptabteilung Sicherheitswesen)

    1989-08-17

    Escape chambers are used in special cases in German mines for self-rescue of the work force. On the basis of the newly laid down requirements concerning escape chambers a specification for mobile escape chambers was drawn up. The Safety Department of Bergbau AG Westfalen purchased two escape chambers of different manufacturers for 10 persons in each case, which are curently being tested at collieries of Bergbau AG Westfalen. The German coal mining industry thus has escape chambers at its disposal to make self-rescue of the work force even safer in the event of difficult and long escape routes. (orig.).

  20. Formulation of a Cooperative-Confinement-Escape problem of multiple cooperative defenders against an evader escaping from a circular region

    Science.gov (United States)

    Li, Wei

    2016-10-01

    In this paper, we propose and formulate the Cooperative-Confinement-Escape (CCE) problem of multiple cooperative defenders against an evader escaping from a circular region, in which the defenders are moving on the circle with attempt to prevent possible escape of a single evader who is initially located inside the circle. The main contributions are summarized as follows: (1) we first provide an effective formulation of the CCE problem, which is an emphasis of this paper, with design of two nonlinear control strategies for the cooperative defenders and the adversarial evader, respectively. Particularly, we consider to include a proper interaction between each pair of the nearest-neighbor defenders, and an adaptive trajectory prediction mechanism in the strategies of the defenders to increase the chance of successful confinement. (2) For the first attempt on analyzing the CCE dynamics which is unavoidably strongly nonlinear, we analyze the minimum energy of the evader for possible escape. (3) For understanding of the behaviors of the system under different parameters, (i) we illustrate the effectiveness of the confinement strategy using the adaptive trajectory prediction mechanism, and (ii) the physical roles of the system parameters with respect to the system dynamics, some of which may be unexpected or not straightforward. A separate paper will be presented for systematic analysis of the agents' behaviors with respect to the large intervals of the parameter settings.

  1. An Empirical Investigation of Time-Out with and without Escape Extinction to Treat Escape-Maintained Noncompliance

    Science.gov (United States)

    Everett, Gregory E.; Olmi, D. Joe; Edwards, Ron P.; Tingstrom, Daniel H.; Sterling-Turner, Heather E.; Christ, Theodore J.

    2007-01-01

    The present study evaluates the effectiveness of two time-out (TO) procedures in reducing escape-maintained noncompliance of 4 children. Noncompliant behavioral function was established via a functional assessment (FA), including indirect and direct descriptive procedures and brief confirmatory experimental analyses. Following FA, parents were…

  2. Integrating Timetabling and Crew Scheduling at a Freight Railway Operator

    NARCIS (Netherlands)

    L. Bach (Lucas); T.A.B. Dollevoet (Twan); D. Huisman (Dennis)

    2014-01-01

    markdownabstract__Abstract__ We investigate to what degree we can integrate a Train Timetabling / Engine Scheduling Problem with a Crew Scheduling Problem. In the Timetabling Problem we design a timetable for the desired lines by fixing the departure and arrival times. Also, we allocate time-slots

  3. Ergonomic and anthropometric issues of the forward Apache crew station

    NARCIS (Netherlands)

    Oudenhuijzen, A.J.K.

    1999-01-01

    This paper describes the anthropometric accommodation in the Apache crew systems. These activities are part of a comprehensive project, in a cooperative effort from the Armstrong Laboratory at Wright Patterson Air Force Base (Dayton, Ohio, USA) and TNO Human Factors Research Institute (TNO HFRI) in

  4. Bullying 101: The Club Crew's Guide to Bullying Prevention

    Science.gov (United States)

    PACER Center, 2013

    2013-01-01

    "Bullying 101" is the Club Crew's Guide to Bullying Prevention. A visually-friendly, age-appropriate, 16-page colorful guide for students to read or for parents to use when talking with children, this guide describes and explains what bullying is and is not, the roles of other students, and tips on what each student can do to prevent…

  5. SCOPE : an intelligent maintenance system for supporting crew operations

    NARCIS (Netherlands)

    Bos, A.; Breebaart, L.; Neerincx, M.A.; Wolff, M.

    2004-01-01

    This paper describes an intelligent maintenance system for Supporting Crew OPErations (SCOPE). SCOPE supports the astronauts onboard the ISS and helps them to maximize the availability of complex payload systems. SCOPE detects system failures, guides the isolation of the root causes of failure, and

  6. Routing helicopters for crew exchanges on off-shore locations

    NARCIS (Netherlands)

    Sierksma, G.; Tijssen, G.A.

    1998-01-01

    This paper deals with a vehicle routing problem with split demands, namely the problem of determining a flight schedule for helicopters to off-shore platform locations for exchanging crew people employed on these platforms. The problem is formulated as an LP model and solved by means of a column-gen

  7. 19 CFR 122.46 - Crew purchase list.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Crew purchase list. 122.46 Section 122.46 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements...

  8. 19 CFR 122.44 - Crew baggage declaration.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Crew baggage declaration. 122.44 Section 122.44 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Entry and Entry Documents; Electronic Manifest Requirements...

  9. Crew Endurance Management Practices: A Guide for Maritime Operations

    Science.gov (United States)

    2003-01-01

    Watchkeeping for Seafarers ( STCW ) regarding hours of work and rest. The fundamental purpose of this guide is to provide managers, captains, department...should use this information, along with the guidelines provided in OPA 90 and STCW : • To identify risk factors affecting crew endurance in specific

  10. STS-103 crew wait inside Discovery for simulated countdown exercise

    Science.gov (United States)

    1999-01-01

    STS-103 Mission Commander Curtis L. Brown Jr. sits inside orbiter Discovery waiting for the start of a simulated countdown exercise. The simulation is part of Terminal Countdown Demonstration Test (TCDT) activities. The TCDT also provides the crew with emergency egress training and opportunities to inspect their mission payload in the orbiter's payload bay. Other crew members taking part in the TCDT are Pilot Scott J. Kelly, and Mission Specialists Steven L. Smith, C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.), Jean-Fran'''ois Clervoy of France, and Claude Nicollier of Switzerland. Clervoy and Nicollier are with the European Space Agency. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  11. Asteroid Redirect Crewed Mission Nominal Design and Performance

    Science.gov (United States)

    Condon, Gerald; williams, Jacob

    2014-01-01

    In 2010, the President announced that, in 2025, the U.S. intended to launch a human mission to an asteroid [1]. This announcement was followed by the idea of a Capability Driven Framework (CDF) [2], which is based on the idea of evolving capabilities from less demanding to more demanding missions to multiple possible destinations and with increased flexibility, cost effectiveness and sustainability. Focused missions, such as a NASA inter-Center study that examined the viability and implications of sending a crew to a Near Earth Asteroid (NEA) [3], provided a way to better understand and evaluate the utility of these CDF capabilities when applied to an actual mission. The long duration of the NEA missions were contrasted with a concept described in a study prepared for the Keck Institute of Space Studies (KISS) [4] where a robotic spacecraft would redirect an asteroid to the Earth-Moon vicinity, where a relatively short duration crewed mission could be conducted to the captured asteroid. This mission concept was included in the National Aeronautics and Space Administration (NASA) fiscal year 2014 budget request, as submitted by the NASA Administrator [5]. NASA studies continued to examine the idea of a crewed mission to a captured asteroid in the Earth-Moon vicinity. During this time was an announcement of NASA's Asteroid Grand Challenge [6]. Key goals for the Asteroid Grand Challenge are to locate, redirect, and explore an asteroid, as well as find and plan for asteroid threats. An Asteroid Redirect Mission (ARM) study was being conducted, which supports this Grand Challenge by providing understanding in how to execute an asteroid rendezvous, capture it, and redirect it to Earth-Moon space, and, in particular, to a distant retrograde orbit (DRO). Subsequent to the returning of the asteroid to a DRO, would be the launch of a crewed mission to rendezvous with the redirected asteroid. This report examines that crewed mission by assessing the Asteroid Redirect Crewed

  12. Crew Exploration Vehicle (CEV) Potable Water System Verification Description

    Science.gov (United States)

    Peterson, Laurie; DeVera, Jean; Vega, Leticia; Adam, Nik; Steele, John; Gazda, Daniel; Roberts, Michael

    2009-01-01

    The Crew Exploration Vehicle (CEV), also known as Orion, will ferry a crew of up to six astronauts to the International Space Station (ISS), or a crew of up to four astronauts to the moon. The first launch of CEV is scheduled for approximately 2014. A stored water system on the CEV will supply the crew with potable water for various purposes: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain quality of the water transferred from the Orbiter to the ISS and stored in Contingency Water Containers (CWCs). In the CEV water system, the ionic silver biocide is expected to be depleted from solution due to ionic silver plating onto the surfaces of the materials within the CEV water system, thus negating its effectiveness as a biocide. Since the biocide depletion is expected to occur within a short amount of time after loading the water into the CEV water tanks at the Kennedy Space Center (KSC), an additional microbial control is a 0.1 micron point of use filter that will be used at the outlet of the Potable Water Dispenser (PWD). Because this may be the first time NASA is considering a stored water system for longterm missions that does not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point of use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform testing to help alleviate those concerns related to the CEV water system. Results from the test plans laid out in the paper presented to SAE last year (Crew Exploration Vehicle (CEV) Potable Water System Verification Coordination, 2008012083) will be detailed in this paper. Additionally, recommendations for the CEV verification will be described for risk mitigation in meeting the physicochemical and microbiological requirements on the CEV PWS.

  13. STS-103 crew look over payload inside Discovery

    Science.gov (United States)

    1999-01-01

    Members of the STS-103 crew, with representatives from Goddard Space Flight Center, look over the Hubble servicing cargo in the payload bay of Space Shuttle Discovery at Launch Pad 39B. From left are Mission Specialist Steven L. Smith and Claude Nicollier of Switzerland; Steve Pataki and Dave Southwick, with Goddard; and Mission Commander Curtis L. Brown Jr. Inspecting the payload is part of the Terminal Countdown Demonstration Test (TCDT), which also provides the crew with emergency egress training and a simulated countdown exercise. Other crew members taking part in the TCDT are Pilot Scott J. Kelly, and Mission Specialists C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.), and Jean- Fran'''ois Clervoy of France. Clervoy and Nicollier are with the European Space Agency. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  14. 75 FR 18825 - Advantage Electronic Product Development Incorporated/Utility Crew Safety LLC

    Science.gov (United States)

    2010-04-13

    ... Advantage Electronic Product Development Incorporated/Utility Crew Safety LLC AGENCY: Department of Energy... intent to grant to: Advantage Electronic Product Development Incorporated/Utility Crew Safety LLC, of... enhanced. Advantage Electronic Product Development Incorporated/Utility Crew Safety LLC, of...

  15. 20 CFR 404.1074 - Farm crew leader who is self-employed.

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Farm crew leader who is self-employed. 404.1074 Section 404.1074 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND... § 404.1074 Farm crew leader who is self-employed. If you are a farm crew leader and are deemed...

  16. 75 FR 75 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Crew Rest Compartment

    Science.gov (United States)

    2010-01-04

    ... Model 787-8 Airplane; Overhead Crew Rest Compartment AGENCY: Federal Aviation Administration (FAA), DOT... installation of an overhead crew rest compartment. The applicable airworthiness regulations do not contain... Design Features Crew rest compartments have been installed and certificated on several Boeing...

  17. 76 FR 10476 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Crew-Rest Compartment

    Science.gov (United States)

    2011-02-25

    ... Crew- Rest Compartment AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special... will have novel or unusual design features associated with installation of an overhead crew-rest (OCR... Sec. 21.101. Novel or Unusual Design Features Crew-rest compartments have been installed...

  18. 14 CFR 417.311 - Flight safety crew roles and qualifications.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Flight safety crew roles and qualifications... crew roles and qualifications. (a) A flight safety crew must operate the flight safety system hardware... must include: (1) Mission specific training programs to ensure team readiness. (2) Launch...

  19. Stream life of spawning pink salmon and the method of escapement enumeration by aerial survey: Draft

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Aerial surveys are currently used as the method tor escapement enumeration of pink salmon throughout Alaska. Other escapement enumeration methods cannot be...

  20. Parameter Optimization on Experimental Study to Reduce Ammonia Escape in CO2 Absorption by Ammonia Scrubbing

    Institute of Scientific and Technical Information of China (English)

    Hao Leng; Jianmin Gao; Mingyue He; Min Xie; Qian Du; Rui Sun; Shaohua Wu

    2016-01-01

    In order to research ammonia escape in CO2 absorption by ammonia scrubbing, ammonia escape was studied in CO2 absorption process using the bubbling reactor in different conditions as gas flow rate, CO2 ratio, absorbent temperature and ammonia concentration and quantity of escaped ammonia was measured by chemical titration. The results indicated that, the amount of ammonia escape can be around 20% of original amount in 90 min and the escaped amount will increase with the rise of gas flow rate, absorbent temperature, concentration of ammonia while decrease as CO2 ratio goes up. Through the analysis of the law of ammonia escape, at the same time, combined with ammonia escape and the influence of the relationship between the CO2 absorption efficiency, reducing ammonia escape working condition parameter optimization is given.

  1. Designing institutions for global democracy: flexibility through escape clauses and sunset provisions

    Directory of Open Access Journals (Sweden)

    Jonathan W. Kuyper

    2013-12-01

    Full Text Available How can advocates of global democracy grapple with the empirical conditions that constitute world politics? I argue that flexibility mechanisms—;commonly used to advance international cooperation—should be employed to make the institutional design project of global democracy more tractable. I highlight three specific reasons underpinning this claim. First, flexibility provisions make bargaining over different institutional designs more manageable. Second, heightened flexibility takes seriously potential concerns about path-dependent institutional development. Finally, deliberately shortening the time horizons of agents by employing flexibility provisions has cognitive benefits as it forces designers to focus specifically on issues of feasibility as well as desirability. I discuss a range of flexibility mechanisms and highlight the utility of sunset provisions and escape clauses. From this analysis, I build an argument for the usage of small-scale democratic experiments through which citizens (or their representatives have a say in global policy making.

  2. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling System for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Wilkes, Robert; Kuehnel, Eric

    2014-01-01

    Development of the Advanced Extravehicular Mobility Unit (AEMU) portable life support subsystem (PLSS) is currently under way at NASA Johnson Space Center. The AEMU PLSS features a new evaporative cooling system, the Generation 4 Spacesuit Water Membrane Evaporator (Gen4 SWME). The SWME offers several advantages when compared with prior crewmember cooling technologies, including the ability to reject heat at increased atmospheric pressures, reduced loop infrastructure, and higher tolerance to fouling. Like its predecessors, Gen4 SWME provides nominal crew member and electronics cooling by flowing water through porous hollow fibers. Water vapor escapes through the hollow fiber pores, thereby cooling the liquid water that remains inside of the fibers. This cooled water is then recirculated to remove heat from the crew member and PLSS electronics. Test results from the backup cooling system which is based on a similar design and the subject of a companion paper, suggested that further volume reductions could be achieved through fiber density optimization. Testing was performed with four fiber bundle configurations ranging from 35,850 fibers to 41,180 fibers. The optimal configuration reduced the Gen4 SWME envelope volume by 15% from that of Gen3 while dramatically increasing the performance margin of the system. A rectangular block design was chosen over the Gen3 cylindrical design, for packaging configurations within the AEMU PLSS envelope. Several important innovations were made in the redesign of the backpressure valve which is used to control evaporation. A twin-port pivot concept was selected from among three low profile valve designs for superior robustness, control and packaging. The backpressure valve motor, the thermal control valve, delta pressure sensors and temperature sensors were incorporated into the manifold endcaps, also for packaging considerations. Flight-like materials including a titanium housing were used for all components. Performance testing

  3. Escape rate of active particles in the effective equilibrium approach

    Science.gov (United States)

    Sharma, A.; Wittmann, R.; Brader, J. M.

    2017-01-01

    The escape rate of a Brownian particle over a potential barrier is accurately described by the Kramers theory. A quantitative theory explicitly taking the activity of Brownian particles into account has been lacking due to the inherently out-of-equilibrium nature of these particles. Using an effective equilibrium approach [Farage et al., Phys. Rev. E 91, 042310 (2015), 10.1103/PhysRevE.91.042310] we study the escape rate of active particles over a potential barrier and compare our analytical results with data from direct numerical simulation of the colored noise Langevin equation. The effective equilibrium approach generates an effective potential that, when used as input to Kramers rate theory, provides results in excellent agreement with the simulation data.

  4. Partial control of chaotic transients using escape times

    Energy Technology Data Exchange (ETDEWEB)

    Sabuco, Juan; Zambrano, Samuel; Sanjuan, Miguel A F, E-mail: juan.sabuco@urjc.e [Departamento de Fisica, Universidad Rey Juan Carlos, Tulipan s/n, 28933 Mostoles, Madrid (Spain)

    2010-11-15

    The partial control technique allows one to keep the trajectories of a dynamical system inside a region where there is a chaotic saddle and from which nearly all the trajectories diverge. Its main advantage is that this goal is achieved even if the corrections applied to the trajectories are smaller than the action of environmental noise on the dynamics, a counterintuitive result that is obtained by using certain safe sets. Using the Henon map as a paradigm, we show here the deep relationship between the safe sets and the sets of points with different escape times, the escape time sets. Furthermore, we show that it is possible to find certain extended safe sets that can be used instead of the safe sets in the partial control technique. Numerical simulations confirm our findings and show that in some situations, the use of extended safe sets can be more advantageous.

  5. Behavioral analysis of the escape response in larval zebrafish

    Science.gov (United States)

    Feng, Ruopei; Girdhar, Kiran; Chemla, Yann; Gruebele, Martin

    The behavior of larval zebrafish is of great interest because the limited number of locomotor neurons in larval zebrafish couples with its rich repertoire of movements as a vertebrate animal. Current research uses a priori-selected parameters to describe their swimming behavior while our lab has built a parameter-free model based on singular value decomposition analysis to characterize it. Our previous work has analyzed the free swimming of larval zebrafish and presented a different picture from the current classification of larval zebrafish locomotion. Now we are extending this work to the studies of their escape response to acoustic stimulus. Analysis has shown intrinsic difference in the locomotion between escape response and free swimming.

  6. Bacillus anthracis Factors for Phagosomal Escape

    Directory of Open Access Journals (Sweden)

    Irene Zornetta

    2012-07-01

    Full Text Available The mechanism of phagosome escape by intracellular pathogens is an important step in the infectious cycle. During the establishment of anthrax, Bacillus anthracis undergoes a transient intracellular phase in which spores are engulfed by local phagocytes. Spores germinate inside phagosomes and grow to vegetative bacilli, which emerge from their resident intracellular compartments, replicate and eventually exit from the plasma membrane. During germination, B. anthracis secretes multiple factors that can help its resistance to the phagocytes. Here the possible role of B. anthracis toxins, phospholipases, antioxidant enzymes and capsules in the phagosomal escape and survival, is analyzed and compared with that of factors of other microbial pathogens involved in the same type of process.

  7. Dynamics of the verge and foliot clock escapement

    CERN Document Server

    Hoyng, P

    2016-01-01

    The verge and foliot escapement has received relatively little attention in horology, despite the fact that it has been used in clocks for ages. We analyse the operation of a verge and foliot escapement in stationary swing. It is driven by a torque $m=\\pm\\mu$, switching sign at fixed swing angles $\\pm\\phi_0$, and $\\mu$ is taken to be constant. Friction is assumed to exert a torque proportional to the angular speed. We determine the shape of the swing angle $\\varphi(t)$, and compute the period and the swing amplitude of the foliot as a function of the model parameters. We find that the period of the foliot scales as $P\\propto\\mu^{-1}$ for weak driving, gradually changing into $P\\propto\\mu^{-1/3}$ for strong driving (large $\\mu$), which underlines that the motion of the foliot is not isochonous.

  8. Quantum and thermal phase escape in extended Josephson systems

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, A.

    2006-07-12

    In this work I examine phase escape in long annular Josephson tunnel junctions. The sine-Gordon equation governs the dynamics of the phase variable along the junction. This equation supports topological soliton solutions, which correspond to quanta of magnetic flux trapped in the junction barrier. For such Josephson vortices an effective potential is formed by an external magnetic field, while a bias current acts as a driving force. Both together form a metastable potential well, which the vortex is trapped in. When the driving force exceeds the pinning force of the potential, the vortex escapes and the junction switches to the voltage state. At a finite temperature the driving force fluctuates. If the junction's energy scale is small, the phase variable can undergo a macroscopic quantum tunneling (MQT) process at temperatures below the crossover temperature. Without a vortex trapped, the metastable state is not a potential minimum in space, but a potential minimum at zero phase difference. (orig.)

  9. Escape Time of Josephson Junctions for Signal Detection

    CERN Document Server

    Addesso, P; Pierro, V

    2014-01-01

    In this Chapter we investigate with the methods of signal detection the response of a Josephson junction to a perturbation to decide if the perturbation contains a coherent oscillation embedded in the background noise. When a Josephson Junction is irradiated by an external noisy source, it eventually leaves the static state and reaches a steady voltage state. The appearance of a voltage step allows to measure the time spent in the metastable state before the transition to the running state, thus defining an escape time. The distribution of the escape times depends upon the characteristics of the noise and the Josephson junction. Moreover, the properties of the distribution depends on the features of the signal (amplitude, frequency and phase), which can be therefore inferred through the appropriate signal processing methods. Signal detection with JJ is interesting for practical purposes, inasmuch as the superconductive elements can be (in principle) cooled to the absolute zero and therefore can add (in practi...

  10. Escape of Mars atmospheric carbon through time by photochemical means

    Science.gov (United States)

    Luhmann, J. G.; Kim, J.; Nagy, A. F.

    Luhmann et al. recently suggested that sputtering of the Martian atmosphere by re-entering O(+) pickup ions could have provided a significant route of escape for CO2 and its products throughout Mars' history. They estimated that the equivalent of C in an approximately 140-mbar CO2 atmosphere should have been lost this way if the Sun and solar wind evolved according to available models. Another source of escaping C (and O) that is potentially important is the dissociative recombination of ionospheric CO(+) near the exobase. We have evaluated the loss rates due to this process for 'ancient' solar EUV radiation fluxes of 1, 3, and 6 times the present flux in order to calculate the possible cumulative loss over the last 3.5 Gyr.

  11. The Biomolecule Sequencer Project: Nanopore Sequencing as a Dual-Use Tool for Crew Health and Astrobiology Investigations

    Science.gov (United States)

    John, K. K.; Botkin, D. S.; Burton, A. S.; Castro-Wallace, S. L.; Chaput, J. D.; Dworkin, J. P.; Lehman, N.; Lupisella, M. L.; Mason, C. E.; Smith, D. J.; Stahl, S; Switzer, C.

    2016-01-01

    Human missions to Mars will fundamentally transform how the planet is explored, enabling new scientific discoveries through more sophisticated sample acquisition and processing than can currently be implemented in robotic exploration. The presence of humans also poses new challenges, including ensuring astronaut safety and health and monitoring contamination. Because the capability to transfer materials to Earth will be extremely limited, there is a strong need for in situ diagnostic capabilities. Nucleotide sequencing is a particularly powerful tool because it can be used to: (1) mitigate microbial risks to crew by allowing identification of microbes in water, in air, and on surfaces; (2) identify optimal treatment strategies for infections that arise in crew members; and (3) track how crew members, microbes, and mission-relevant organisms (e.g., farmed plants) respond to conditions on Mars through transcriptomic and genomic changes. Sequencing would also offer benefits for science investigations occurring on the surface of Mars by permitting identification of Earth-derived contamination in samples. If Mars contains indigenous life, and that life is based on nucleic acids or other closely related molecules, sequencing would serve as a critical tool for the characterization of those molecules. Therefore, spaceflight-compatible nucleic acid sequencing would be an important capability for both crew health and astrobiology exploration. Advances in sequencing technology on Earth have been driven largely by needs for higher throughput and read accuracy. Although some reduction in size has been achieved, nearly all commercially available sequencers are not compatible with spaceflight due to size, power, and operational requirements. Exceptions are nanopore-based sequencers that measure changes in current caused by DNA passing through pores; these devices are inherently much smaller and require significantly less power than sequencers using other detection methods

  12. The C. elegans touch response facilitates escape from predacious fungi

    OpenAIRE

    Maguire, Sean M.; Clark, Christopher M.; Nunnari, John; Pirri, Jennifer K.; Alkema, Mark J.

    2011-01-01

    Predator-prey interactions are vital determinants in the natural selection of behavioral traits. However, we have few insights into both the neural mechanisms and the selective advantage of specific behavioral traits. Gentle touch to the anterior half of the body of Caenorhabditis elegans elicits an escape response in which the animal quickly reverses and suppresses exploratory head movements [1]. Even though the C. elegans touch response has provided one of the rare examples of how neural ne...

  13. Escape Geography--Developing Middle-School Students' Sense of Place.

    Science.gov (United States)

    Allen, Rodney F.; Molina, Laurie E. S.

    1992-01-01

    Suggests a social studies unit on escaping geography. Examines escape from dangerous places including an airliner, hotel fire, or war zone or from a social situation such as a boring speech or party. Describes historic escapes such as the Underground Railroad and the Berlin Wall. Lists learning strategies such as awareness of space and cognitive…

  14. On the Relative Contributions of Noncontingent Reinforcement and Escape Extinction in the Treatment of Food Refusal

    Science.gov (United States)

    Reed, Gregory K.; Piazza, Cathleen C.; Patel, Meeta R.; Layer, Stacy A.; Bachmeyer, Melanie H.; Bethke, Stephanie D.; Gutshall, Katharine A.

    2004-01-01

    In the current investigation, we evaluated the relative effects of noncontingent reinforcement (NCR), escape extinction, and a combination of NCR and escape extinction as treatment for the feeding problems exhibited by 4 children. For each participant, consumption increased only when escape extinction was implemented, independent of whether NCR…

  15. 46 CFR 56.50-25 - Safety and relief valve escape piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Safety and relief valve escape piping. 56.50-25 Section 56.50-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-25 Safety and relief valve escape piping. (a) Escape piping...

  16. MAVEN in situ measurements of photochemical escape of oxygen from Mars

    Science.gov (United States)

    Lillis, Robert; Deighan, Justin; Fox, Jane; Bougher, Stephen; Lee, Yuni; Cravens, Thomas; Rahmati, Ali; Mahaffy, Paul; Benna, Mehdi; Groller, Hannes; Jakosky, Bruce

    2016-04-01

    One of the primary goals of the MAVEN mission is to characterize rates of atmospheric escape from Mars at the present epoch and relate those escape rates to solar drivers. One of the known escape processes is photochemical escape, where a) an exothermic chemical reaction in the atmosphere results in an upward-traveling neutral particle whose velocity exceeds planetary escape velocity and b) the particle is not prevented from escaping through subsequent collisions. At Mars, photochemical escape of oxygen is expected to be a significant channel for atmospheric escape, particularly in the early solar system when extreme ultraviolet (EUV) fluxes were much higher. Thus characterizing this escape process and its variability with solar drivers is central to understanding the role escape to space has played in Mars' climate evolution. We use near-periapsis (atoms. The second is a Monte Carlo hot atom transport model that takes that distribution of initial O energies and the measured neutral density profiles and calculates the probability that a hot atom born at that altitude will escape. The third takes the measured electron and ion densities and electron temperatures and calculates the production rate of hot O atoms. We then multiply together the profiles of hot atom production and escape probability to get profiles of the production rate of escaping atoms. We integrate with respect to altitude to give us the escape flux of hot oxygen atoms for that periapsis pass. We have sufficient coverage in solar zenith angle (SZA) to estimate total escape rates for two intervals with the obvious assumption that escape rates are the same at all points with the same SZA. We estimate total escape rates of 3.5-5.8 x 1025 s-1 for Ls = 289° to 319° and 1.6-2.6 x 1025 s-1 for Ls = 326° to 348°. The latter is the most directly comparable to previous model-based estimates and is roughly in line with several of them. Total photochemical loss over Mars history is not very useful to

  17. Understanding the International Space Station Crew Perspective following Long-Duration Missions through Data Analytics & Visualization of Crew Feedback

    Science.gov (United States)

    Bryant, Cody; Meza, David; Schoenstein, Nicole; Schuh, Susan

    2017-01-01

    The International Space Station (ISS) first became a home and research laboratory for NASA and International Partner crewmembers over 16 years ago. Each ISS mission lasts approximately 6 months and consists of three to six crewmembers. After returning to Earth, most crewmembers participate in an extensive series of 30+ debriefs intended to further understand life onboard ISS and allow crews to reflect on their experiences. Examples of debrief data collected include ISS crew feedback about sleep, dining, payload science, scheduling and time planning, health & safety, and maintenance. The Flight Crew Integration (FCI) Operational Habitability (OpsHab) team, based at Johnson Space Center (JSC), is a small group of Human Factors engineers and one stenographer that has worked collaboratively with the NASA Astronaut office and ISS Program to collect, maintain, disseminate and analyze this data. The database provides an exceptional and unique resource for understanding the "crew perspective" on long duration space missions. Data is formatted and categorized to allow for ease of search, reporting, and ultimately trending, in order to understand lessons learned, recurring issues and efficiencies gained over time. Recently, the FCI OpsHab team began collaborating with the NASA JSC Knowledge Management team to provide analytical analysis and visualization of these over 75,000 crew comments in order to better ascertain the crew's perspective on long duration spaceflight and gain insight on changes over time. In this initial phase of study, a text mining framework was used to cluster similar comments and develop measures of similarity useful for identifying relevant topics affecting crew health or performance, locating similar comments when a particular issue or item of operational interest is identified, and providing search capabilities to identify information pertinent to future spaceflight systems and processes for things like procedure development and training. In addition

  18. Reduced Crew Operations Research at NASA Ames Research Center

    Science.gov (United States)

    Brandt, Summer L.; Lachter, Joel

    2017-01-01

    In 2012, NASA began exploring the feasibility of single pilot reduced crew operations (SPORCO) in the context of scheduled passenger air carrier operations (i.e., Parts 121 and 135). This research was spurred by two trends in aviation research: the trend toward reducing costs and a shortage of pilots. A series of simulations were conducted to develop tools and a concept of operations to support RCO. This slide deck is a summary of the NASA Ames RCO research prepared for an R T team at Airbus. Airbus is considering moving forward with reducing crew during the cruise phase of flight with long-haul flights and is interested in the work we have completed.

  19. Preflight and postflight microbiological results from 25 space shuttle crews

    Science.gov (United States)

    Pierson, Duane L.; Bassinger, Virginia J.; Molina, Thomas C.; Gunter, Emelie G.; Groves, Theron O.; Cioletti, Louis J.; Mishra, S. K.

    1993-01-01

    Clinical-microbiological investigations are an important aspect of the crew health stabilization program. To ensure that space crews have neither active nor latent infections, clinical specimens, including throat and nasal swabs and urine samples, are collected at 10 days (L-10) and 2days (L-2) before launch, and immediately after landing (L+0). All samples are examined for the presence of bacteria and fungi. In addition, fecal samples are collected at L-10 and examined for bacteria, fungi and parasites. This paper describes clinical-microbiological findings from 144 astronauts participating in 25 Space Shuttle missions spanning Space Transportation System (STS)-26 to STS-50. The spectrum of microbiological findings from the specimens included 25 bacterial and 11 fungal species. Among the bacteria isolated most frequently were Staphylococcus aureus, Enterobacter aerogenes, Enterococcus faecalis, Escherichia coli, Proteus mirabilis and Streptococcus agalactiae. Candida albicans was the most frequently isolated fungal pathogen.

  20. Croatian Airports as Potential European Flight Crew Training Centres

    Directory of Open Access Journals (Sweden)

    Tomislav Gradišar

    2012-10-01

    Full Text Available The paper deals with the possibilities of offering Croatianailports as potential flight crew training centres on the Europeanmarket of se!Vices. With her available ai1port capacities,mainly those located on the Adriatic coast, Croatia has significantadvantages compared to other countries of Westem andCentral Europe. The most important condition for establishinga specialised training centre for the European market is the harmonisationof the national aviation regulations i.e. the implementationof global and European standards of flight crewtraining, as well as conditions that have to be met by a specialisedtraining centre from the aspect of the necessary infrastructure.The study has evaluated the potential airports of Rijeka,Pula and Losinj, acc01ding to the basic criteria of their geo-Lraffic location, infrastructure resources (technical elements ofrunway, navigation equipment, abport se1vices, availability ofspecial equipment for flight crew training on the ground and inthe ail; as well as climate conditions.

  1. Reentry Thermal Analysis of a Generic Crew Exploration Vehicle Structure

    Science.gov (United States)

    Ko, William L.; Gong, Leslie; Quinn, Robert D.

    2007-01-01

    Comparative studies were performed on the heat-shielding characteristics of honeycomb-core sandwich panels fabricated with different materials for possible use as wall panels for the proposed crew exploration vehicle. Graphite/epoxy sandwich panel was found to outperform aluminum sandwich panel under the same geometry due to superior heat-shielding qualities and lower material density. Also, representative reentry heat-transfer analysis was performed on the windward wall structures of a generic crew exploration vehicle. The Apollo low Earth orbit reentry trajectory was used to calculate the reentry heating rates. The generic crew exploration vehicle has a graphite/epoxy composite honeycomb sandwich exterior wall and an aluminum honeycomb sandwich interior wall, and is protected with the Apollo thermal protection system ablative material. In the thermal analysis computer program used, the TPS ablation effect was not yet included; however, the results from the nonablation heat-transfer analyses were used to develop a "virtual ablation" method to estimate the ablation heat loads and the thermal protection system recession thicknesses. Depending on the severity of the heating-rate time history, the virtual ablation period was found to last for 87 to 107 seconds and the ablation heat load was estimated to be in the range of 86 to 88 percent of the total heat load for the ablation time period. The thermal protection system recession thickness was estimated to be in the range of 0.08 to 0.11 inches. For the crew exploration vehicle zero-tilt and 18-degree-tilt stagnation points, thermal protection system thicknesses of h = {0.717, 0.733} inches were found to be adequate to keep the substructural composite sandwich temperature below the limit of 300 F.

  2. Flashline Mars Arctic Research Station (FMARS) 2009 Expedition Crew Perspectives

    Science.gov (United States)

    Cusack, Stacy; Ferrone, Kristine; Garvin, Christy; Kramer, W. Vernon; Palaia, Joseph, IV; Shiro, Brian

    2009-01-01

    The Flashline Mars Arctic Research Station (FMARS), located on the rim of the Haughton Crater on Devon Island in the Canadian Arctic, is a simulated Mars habitat that provides operational constraints similar to those which will be faced by future human explorers on Mars. In July 2009, a six-member crew inhabited the isolated habitation module and conducted the twelfth FMARS mission. The crew members conducted frequent EVA operations wearing mock space suits to conduct field experiments under realistic Mars-like conditions. Their scientific campaign spanned a wide range of disciplines and included many firsts for Mars analog research. Among these are the first use of a Class IV medical laser during a Mars simulation, helping to relieve crew stress injuries during the mission. Also employed for the first time in a Mars simulation at FMARS, a UAV (Unmanned Aerial Vehicle) was used by the space-suited explorers, aiding them in their search for mineral resources. Sites identified by the UAV were then visited by geologists who conducted physical geologic sampling. For the first time, explorers in spacesuits deployed passive seismic equipment to monitor earthquake activity and characterize the planet's interior. They also conducted the first geophysical electromagnetic survey as analog Mars pioneers to search for water and characterize geological features under the surface. The crew collected hydrated minerals and attempted to produce drinkable water from the rocks. A variety of equipment was field tested as well, including new cameras that automatically geotag photos, data-recording GPS units, a tele-presence rover (operated from Florida), as well as MIT-developed mission planning software. As plans develop to return to the Moon and go on to Mars, analog facilities like FMARS can provide significant benefit to NASA and other organizations as they prepare for robust human space exploration. The authors will present preliminary results from these studies as well as their

  3. Crew resource management training--clinicians' reactions and attitudes.

    Science.gov (United States)

    France, Daniel J; Stiles, Renee; Gaffney, E Andrew; Seddon, Margaret R; Grogan, Eric L; Nixon, William R; Speroff, Theodore

    2005-08-01

    Many health care organizations are adopting crew resource management (CRM) training from the aviation industry as a patient safety practice. Although CRM has high face validity, its effects have not been thoroughly evaluated in aviation or health care. Its potential to improve team communication, coordination, and patient safety, however, makes efforts to study CRM necessary and worthwhile. This article evaluates clinicians' attitudes about and reactions to CRM after they participated in an eight-hour, commercially developed training program.

  4. Determining the Optimal C-130 Deployed Crew Ratio

    Science.gov (United States)

    2014-06-13

    factors such as circadian rhythm and sleep cycle disruption cannot be ignored. The target audience for Fundamentals of Shiftwork Scheduling is not...planning factors, intratheater airlift demand and less quantifiable aspects of crew ratio planning such as circadian rhythm disruption. The initial review...necessarily aircrews, but the principles are similar. Topics covered by Dr. Miller include “fatigue, safety, calendar arithmetic, circadian stability

  5. STS-97 Crew Interview: Carlos Noriega, MS3

    Science.gov (United States)

    2000-01-01

    The STS-97 Mission Specialist Carlos Noriega is seen being interviewed. He answers questions about his inspiration to become an astronaut, his career path, and his training. He gives details on the mission's goals and significance, its payload, the rendez-vous with the International Space Station (ISS), and what it will be like to work knowing there is already a crew on board the ISS.

  6. Real-Time Simulation of Ship Impact for Crew Training

    DEFF Research Database (Denmark)

    Simonsen, Bo Cerup

    2003-01-01

    Real-time simulation of marine accidents and representation in a realistic, virtual environment may be an efficient way to train emergency procedures for ship?s crews and thus improve safety at sea. However, although various fast, simplified methods have been presented over the past decades...... be advantageous to use in other types of time simulation where it is desirable to switch between direct time integration and some other known, stabilized solution, without a major redesign of the program architecture....

  7. STS-103 crew pose in front of Pad 39B

    Science.gov (United States)

    1999-01-01

    During Terminal Countdown Demonstration Test (TDCT) activities at Launch Pad 39B, the STS-103 crew pose in front of the flame trench, which is situated underneath the Mobile Launcher Platform holding Space Shuttle Discovery. Standing left to right are Mission Specialists Claude Nicollier of Switzerland, who is with the European Space Agency (ESA), C. Michael Foale (Ph.D.), John M. Grunsfeld (Ph.D.), Pilot Scott J. Kelly, Commander Curtis L. Brown Jr., and Mission Specialists Jean-Frangois Clervoy of France, also with ESA, and Steven L. Smith. One of the solid rocket boosters and the external tank that are attached to Discovery can be seen in the photo. The flame trench is made of concrete and refractory brick, and contains an orbiter flame deflector on one side and solid rocket booster flame deflector on the other. The deflectors protect the flame trench floor and pad surface from the intense heat of launch. The TCDT provides the crew with emergency egress training, opportunities to inspect their mission payloads in the orbiter's payload bay, and simulated countdown exercises. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  8. Effects of checklist interface on non-verbal crew communications

    Science.gov (United States)

    Segal, Leon D.

    1994-01-01

    The investigation looked at the effects of the spatial layout and functionality of cockpit displays and controls on crew communication. Specifically, the study focused on the intra-cockpit crew interaction, and subsequent task performance, of airline pilots flying different configurations of a new electronic checklist, designed and tested in a high-fidelity simulator at NASA Ames Research Center. The first part of this proposal establishes the theoretical background for the assumptions underlying the research, suggesting that in the context of the interaction between a multi-operator crew and a machine, the design and configuration of the interface will affect interactions between individual operators and the machine, and subsequently, the interaction between operators. In view of the latest trends in cockpit interface design and flight-deck technology, in particular, the centralization of displays and controls, the introduction identifies certain problems associated with these modern designs and suggests specific design issues to which the expected results could be applied. A detailed research program and methodology is outlined and the results are described and discussed. Overall, differences in cockpit design were shown to impact the activity within the cockpit, including interactions between pilots and aircraft and the cooperative interactions between pilots.

  9. Mars Hybrid Propulsion System Trajectory Analysis. Part I; Crew Missions

    Science.gov (United States)

    Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

    2015-01-01

    NASAs Human spaceflight Architecture team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single space- ship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper provides the analysis of the interplanetary segments of the three Evolvable Mars Campaign crew missions to Mars using the hybrid transportation architecture. The trajectory analysis provides departure and arrival dates and propellant needs for the three crew missions that are used by the campaign analysis team for campaign build-up and logistics aggregation analysis. Sensitivity analyses were performed to investigate the impact of mass growth, departure window, and propulsion system performance on the hybrid transportation architecture. The results and system analysis from this paper contribute to analyses of the other human spaceflight architecture team tasks and feed into the definition of the Evolvable Mars Campaign.

  10. Broad CTL Response in Early HIV Infection Drives Multiple Concurrent CTL Escapes.

    Science.gov (United States)

    Leviyang, Sivan; Ganusov, Vitaly V

    2015-10-01

    Recent studies have highlighted the ability of HIV to escape from cytotoxic T lymphocyte (CTL) responses that concurrently target multiple viral epitopes. Yet, the viral dynamics involved in such escape are incompletely understood. Previous analyses have made several strong assumptions regarding HIV escape from CTL responses such as independent or non-concurrent escape from individual CTL responses. Using experimental data from evolution of HIV half genomes in four patients we observe concurrent viral escape from multiple CTL responses during early infection (first 100 days of infection), providing confirmation of a recent result found in a study of one HIV-infected patient. We show that current methods of estimating CTL escape rates, based on the assumption of independent escapes, are biased and perform poorly when CTL escape proceeds concurrently at multiple epitopes. We propose a new method for analyzing longitudinal sequence data to estimate the rate of CTL escape across multiple epitopes; this method involves few parameters and performs well in simulation studies. By applying our novel method to experimental data, we find that concurrent multiple escapes occur at rates between 0.03 and 0.4 day(-1), a relatively broad range that reflects uncertainty due to sparse sampling and wide ranges of parameter values. However, we show that concurrent escape at rates 0.1-0.2 day(-1) across multiple epitopes is consistent with our patient datasets.

  11. A comparison of positive and negative reinforcement for compliance to treat problem behavior maintained by escape.

    Science.gov (United States)

    Slocum, Sarah K; Vollmer, Timothy R

    2015-09-01

    Previous research has shown that problem behavior maintained by escape can be treated using positive reinforcement. In the current study, we directly compared functional (escape) and nonfunctional (edible) reinforcers in the treatment of escape-maintained problem behavior for 5 subjects. In the first treatment, compliance produced a break from instructions. In the second treatment, compliance produced a small edible item. Neither treatment included escape extinction. Results suggested that the delivery of a positive reinforcer for compliance was effective for treating escape-maintained problem behavior for all 5 subjects, and the delivery of escape for compliance was ineffective for 3 of the 5 subjects. Implications and future directions related to the use of positive reinforcers in the treatment of escape behavior are discussed.

  12. In-flight dose estimates for aircraft crew and pregnant female crew members in military transport missions.

    Science.gov (United States)

    Alves, J G; Mairos, J C

    2007-01-01

    Aircraft fighter pilots may experience risks other than the exposure to cosmic radiation due to the characteristics of a typical fighter flight. The combined risks for fighter pilots due to the G-forces, hypobaric hypoxia, cosmic radiation exposure, etc. have determined that pregnant female pilots should remain on ground. However, several military transport missions can be considered an ordinary civil aircraft flight and the question arises whether a pregnant female crew member could still be part of the aircraft crew. The cosmic radiation dose received was estimated for transport missions carried out on the Hercules C-130 type of aircraft by a single air squad in 1 month. The flights departed from Lisboa to areas such as: the Azores, several countries in central and southern Africa, the eastern coast of the USA and the Balkans, and an estimate of the cosmic radiation dose received on each flight was carried out. A monthly average cosmic radiation dose to the aircraft crew was determined and the dose values obtained were discussed in relation to the limits established by the European Union Council Directive 96/29/Euratom. The cosmic radiation dose estimates were performed using the EPCARD v3.2 and the CARI-6 computing codes. EPCARD v3.2 was kindly made available by GSF-National Research Centre for Environment and Health, Institute of Radiation Protection (Neuherberg, Germany). CARI-6 (version July 7, 2004) was downloaded from the web site of the Civil Aerospace Medical Institute, Federal Aviation Administration (USA). In this study an estimate of the cosmic radiation dose received by military aircraft crew on typical transport missions is made.

  13. Experimental analysis and extinction of self-injurious escape behavior.

    Science.gov (United States)

    Iwata, B A; Pace, G M; Kalsher, M J; Cowdery, G E; Cataldo, M F

    1990-01-01

    Three studies are presented in which environmental correlates of self-injurious behavior were systematically examined and later used as the basis for treatment. In Study 1, 7 developmentally disabled subjects were exposed to a series of conditions designed to identify factors that maintain self-injurious behavior: attention contingent on self-injurious behavior (positive reinforcement), escape from or avoidance of demands contingent on self-injurious behaviour (negative reinforcement), alone (automatic reinforcement), and play (control). Results of a multielement design showed that each subject's self-injurious behavior occurred more frequently in the demand condition, suggesting that the behavior served an avoidance or escape function. Six of the 7 subjects participated in Study 2. During educational sessions, "escape extinction" was applied as treatment for their self-injurious behavior in a multiple baseline across subjects design. Results showed noticeable reduction or elimination of self-injurious behavior for each subject and an increase in compliance with instructions in all subjects for whom compliance data were taken. The 7th subject, whose self-injurious behavior during Study 1 occurred in response to medical demands (i.e., physical examinations), participated in Study 3. Treatment was comprised of extinction, as in Study 2, plus reinforcement for tolerance of the examination procedure, and was evaluated in a multiple baseline across settings design. Results showed that the treatment was successful in eliminating self-injurious behavior and that its effects transferred across eight new therapists and three physicians. General implications for the design, interpretation, and uses of assessment studies are discussed.

  14. First-passage and escape problems in the Feller process

    CERN Document Server

    Masoliver, Jaume

    2012-01-01

    The Feller process is an one-dimensional diffusion process with linear drift and state-dependent diffusion coefficient vanishing at the origin. The process is positive definite and it is this property along with its linear character that have made Feller process a convenient candidate for the modeling of a number of phenomena ranging from single neuron firing to volatility of financial assets. While general properties of the process are well known since long, less known are properties related to level crossing such as the first-passage and the escape problems. In this work we thoroughly address these questions.

  15. First-passage and escape problems in the Feller process

    Science.gov (United States)

    Masoliver, Jaume; Perelló, Josep

    2012-10-01

    The Feller process is an one-dimensional diffusion process with linear drift and state-dependent diffusion coefficient vanishing at the origin. The process is positive definite and it is this property along with its linear character that have made Feller process a convenient candidate for the modeling of a number of phenomena ranging from single-neuron firing to volatility of financial assets. While general properties of the process have long been well known, less known are properties related to level crossing such as the first-passage and the escape problems. In this work we thoroughly address these questions.

  16. Chases and escapes the mathematics of pursuit and evasion

    CERN Document Server

    Nahin, Paul J

    2012-01-01

    We all played tag when we were kids. What most of us don't realize is that this simple chase game is in fact an application of pursuit theory, and that the same principles of games like tag, dodgeball, and hide-and-seek are also at play in military strategy, high-seas chases by the Coast Guard, and even romantic pursuits. In Chases and Escapes, Paul Nahin gives us the first complete history of this fascinating area of mathematics, from its classical analytical beginnings to the present day. Drawing on game theory, geometry, linear algebra, target-tracking algorithms, and much

  17. Experimental study of subsonic microjet escaping from a rectangular nozzle

    Science.gov (United States)

    Aniskin, V. M.; Maslov, A. A.; Mukhin, K. A.

    2016-10-01

    The first experiments on the subsonic laminar microjets escaping from the nozzles of rectangular shape are carried out. The nozzle size is 83.3x3823 microns. Reynolds number calculated by the nozzle height and the average flow velocity at the nozzle exit ranged from 58 to 154. The working gas was air at room temperature. The velocity decay and velocity fluctuations along the center line of the jet are determined. The fundamental difference between the laminar microjets characteristics and subsonic turbulent jets of macro size is shown. Based on measurements of velocity fluctuations it is shown the presence of laminar-turbulent transition in microjets and its location is determined.

  18. The mirror of the escaped God – Alejandra Pizarnik

    Directory of Open Access Journals (Sweden)

    Mariano Carou

    2015-04-01

    Full Text Available Alejandra Pizarnik (1936-1972 shows many different stands regarding to “God’s escape” in her poetry and his diaries: from the psalmist’s request to the more combative atheism. There is, however, a constant development of a symbolic constellation to speak about God’s mistery, and the certitude –inherited from German romanticism– that the poet has always something to say about God’s escape, searching for a new hope in which is maybe a new form of mysticism.

  19. Test of time: what if little Albert had escaped?

    Science.gov (United States)

    Field, Andy P; Nightingale, Zoë C

    2009-04-01

    Watson and Rayner's (1920) ;Little Albert' experiment has become one of the most famous studies in psychology. It is a staple of many general psychology textbooks and is part of the very fabric of the discipline's folklore. Despite this fame, the study has been widely criticized in the nearly 90 years since it was published for its lack of methodological rigour. This article attempts to evaluate the contribution of the ;little Albert' study to modern clinical psychology by speculating on what theories and treatments of child anxiety would look like in a parallel universe in which the study never took place because ;little Albert' escaped from the hospital in which Watson tested him.

  20. Desert Rats 2010 Operations Tests: Insights from the Geology Crew Members

    Science.gov (United States)

    Bleacher, J. E.; Hurtado, J. M., Jr.; Young, K. E.; Rice, J.; Garry, W. B.; Eppler, D.

    2011-01-01

    Desert Research and Technology Studies (Desert RATS) is a multi-year series of tests of NASA hardware and operations deployed in the high desert of Arizona. Conducted annually since 1997, these activities exercise planetary surface hardware and operations in relatively harsh conditions where long-distance, multi-day roving is achievable. Such activities not only test vehicle subsystems, they also stress communications and operations systems and enable testing of science operations approaches that advance human and robotic surface exploration capabilities. Desert RATS 2010 tested two crewed rovers designed as first-generation prototypes of small pressurized vehicles, consistent with exploration architecture designs. Each rover provided the internal volume necessary for crewmembers to live and work for periods up to 14 days, as well as allowing for extravehicular activities (EVAs) through the use of rear-mounted suit ports. The 2010 test was designed to simulate geologic science traverses over a 14-day period through a volcanic field that is analogous to volcanic terrains observed throughout the Solar System. The test was conducted between 31 August and 13 September 2010. Two crewmembers lived in and operated each rover for a week with a "shift change" on day 7, resulting in a total of eight test subjects for the two-week period. Each crew consisted of an engineer/commander and an experienced field geologist. Three of the engineer/commanders were experienced astronauts with at least one Space Shuttle flight. The field geologists were drawn from the scientific community, based on funded and published field expertise.

  1. Escape of Hydrogen from the Exosphere of Mars

    Science.gov (United States)

    Bhattacharyya, Dolon; Clarke, John T.; Bertaux, Jean-Loup; Chaufray, Jean-Yves; Mayyasi-Matta, Majd A.

    2016-10-01

    After decades of exploration, the martian neutral hydrogen exosphere has remained largely uncharacterized even today. In my dissertation I have attempted to constrain the characteristics of the martian hydrogen exosphere using Hubble Space Telescope observations obtained during October-November 2007 and 2014. These observations reveal short-term seasonal changes exhibited by the martian hydrogen exosphere that are inconsistent with the diffusion-limited escape scenario. This seasonal behavior adds a new element towards backtracking the history of water loss from Mars. Modeling of the data also indicates the likely presence of a superthermal population of hydrogen created by non-thermal processes at Mars, another key element to understand the present-day escape. Exploration of the latitudinal symmetry of the martian exosphere indicates that it is symmetric above 2.5 martian radii and asymmetric below this altitude, which could be due to temperature differences between the day and night sides. Finally, the large uncertainties in determining the characteristics of the martian exosphere after decades of exploration is due to various assumptions about the intrinsic characteristics of the martian exosphere in the modeling process, degeneracy in the two modeling parameters temperature and density of the hydrogen atoms, unaccounted seasonal effects, and uncertainties introduced from spacecraft instrumentation as well as their viewing geometry.

  2. Metastatic Tumor Dormancy in Cutaneous Melanoma: Does Surgery Induce Escape?

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, William W. [Department of Surgery, University of California at San Francisco, 513 Parnassus Avenue, Room S-321, San Francisco, CA 94143 (United States); Fadaki, Niloofar; Leong, Stanley P., E-mail: leongsx@cpmcri.org [Department of Surgery and Center for Melanoma Research and Treatment, California Pacific Medical Center and Research Institute, 2340 Clay Street, 2nd floor, San Francisco, CA 94115 (United States)

    2011-02-21

    According to the concept of tumor dormancy, tumor cells may exist as single cells or microscopic clusters of cells that are clinically undetectable, but remain viable and have the potential for malignant outgrowth. At metastatic sites, escape from tumor dormancy under more favorable local microenvironmental conditions or through other, yet undefined stimuli, may account for distant recurrence after supposed “cure” following surgical treatment of the primary tumor. The vast majority of evidence to date in support of the concept of tumor dormancy originates from animal studies; however, extensive epidemiologic data from breast cancer strongly suggests that this process does occur in human disease. In this review, we aim to demonstrate that metastatic tumor dormancy does exist in cutaneous melanoma based on evidence from mouse models and clinical observations of late recurrence and occult transmission by organ transplantation. Experimental data underscores the critical role of impaired angiogenesis and immune regulation as major mechanisms for maintenance of tumor dormancy. Finally, we examine evidence for the role of surgery in promoting escape from tumor dormancy at metastatic sites in cutaneous melanoma.

  3. Metastatic Tumor Dormancy in Cutaneous Melanoma: Does Surgery Induce Escape?

    Directory of Open Access Journals (Sweden)

    William W. Tseng

    2011-02-01

    Full Text Available According to the concept of tumor dormancy, tumor cells may exist as single cells or microscopic clusters of cells that are clinically undetectable, but remain viable and have the potential for malignant outgrowth. At metastatic sites, escape from tumor dormancy under more favorable local microenvironmental conditions or through other, yet undefined stimuli, may account for distant recurrence after supposed “cure” following surgical treatment of the primary tumor. The vast majority of evidence to date in support of the concept of tumor dormancy originates from animal studies; however, extensive epidemiologic data from breast cancer strongly suggests that this process does occur in human disease. In this review, we aim to demonstrate that metastatic tumor dormancy does exist in cutaneous melanoma based on evidence from mouse models and clinical observations of late recurrence and occult transmission by organ transplantation. Experimental data underscores the critical role of impaired angiogenesis and immune regulation as major mechanisms for maintenance of tumor dormancy. Finally, we examine evidence for the role of surgery in promoting escape from tumor dormancy at metastatic sites in cutaneous melanoma.

  4. Random fluctuation leads to forbidden escape of particles.

    Science.gov (United States)

    Rodrigues, Christian S; de Moura, Alessandro P S; Grebogi, Celso

    2010-08-01

    A great number of physical processes are described within the context of Hamiltonian scattering. Previous studies have rather been focused on trajectories starting outside invariant structures, since the ones starting inside are expected to stay trapped there forever. This is true though only for the deterministic case. We show however that, under finitely small random fluctuations of the field, trajectories starting inside Kolmogorov-Arnold-Moser (KAM) islands escape within finite time. The nonhyperbolic dynamics gains then hyperbolic characteristics due to the effect of the random perturbed field. As a consequence, trajectories which are started inside KAM curves escape with hyperboliclike time decay distribution, and the fractal dimension of a set of particles that remain in the scattering region approaches that for hyperbolic systems. We show a universal quadratic power law relating the exponential decay to the amplitude of noise. We present a random walk model to relate this distribution to the amplitude of noise, and investigate these phenomena with a numerical study applying random maps.

  5. Ultra-fast Escape of a Octopus-inspired Rocket

    Science.gov (United States)

    Weymouth, Gabriel; Triantafyllou, Michael

    2013-11-01

    The octopus, squid, and other cephalopods inflate with water and then release a jet to accelerate in the opposite direction. This escape mechanism is particularly interesting in the octopus because they become initially quite bluff, yet this does not hinder them in achieving impressive bursts of speed. We examine this somewhat paradoxical maneuver using a simple deflating spheroid model in both potential and viscous flow. We demonstrate that the dynamic reduction of the width of the body completely changes the flow and forces acting on the escaping rocket in three ways. First, a body which reduces in size can generate an added mass thrust which counteracts the added mass inertia. Second, the motion of the shrinking wall acts similar to suction on a static wall, reducing separation and drag forces in a viscous fluid, but that this effects depends on the rate of size change. Third, using a combination of these two features it is possible to initially load the fluid with kinetic energy when heavy and bluff and then recover that energy when streamlined and light, enabling ultra-fast accelerations. As a notable example, these mechanisms allow a shrinking spheroid rocket in a heavy inviscid fluid to achieve speeds greater than an identical rocket in the vacuum of space. Southampton Marine and Maritime Institute.

  6. Slow and Fast Escape for Open Intermittent Maps

    Science.gov (United States)

    Demers, Mark F.; Todd, Mike

    2017-04-01

    If a system mixes too slowly, putting a hole in it can completely destroy the richness of the dynamics. Here we study this instability for a class of intermittent maps with a family of slowly mixing measures. We show that there are three regimes: (1) standard hyperbolic-like behavior where the rate of mixing is faster than the rate of escape through the hole, there is a unique limiting absolutely continuous conditionally invariant measure (accim) and there is a complete thermodynamic description of the dynamics on the survivor set; (2) an intermediate regime, where the rate of mixing and escape through the hole coincide, limiting accims exist, but much of the thermodynamic picture breaks down; (3) a subexponentially mixing regime where the slow mixing means that mass simply accumulates on the parabolic fixed point. We give a complete picture of the transitions and stability properties (in the size of the hole and as we move through the family) in this class of open systems. In particular, we are able to recover a form of stability in the third regime above via the dynamics on the survivor set, even when no limiting accim exists.

  7. The C. elegans touch response facilitates escape from predacious fungi.

    Science.gov (United States)

    Maguire, Sean M; Clark, Christopher M; Nunnari, John; Pirri, Jennifer K; Alkema, Mark J

    2011-08-09

    Predator-prey interactions are vital determinants in the natural selection of behavioral traits. Gentle touch to the anterior half of the body of Caenorhabditis elegans elicits an escape response in which the animal quickly reverses and suppresses exploratory head movements [1, 2]. Here, we investigate the ecological significance of the touch response in predator-prey interactions between C. elegans and predacious fungi that catch nematodes using constricting hyphal rings. We show that the constricting rings of Drechslerella doedycoides catch early larval stages with a diameter similar to the trap opening. There is a delay between the ring entry and ring closure, which allows the animal to withdraw from the trap before being caught. Mutants that fail to suppress head movements in response to touch are caught more efficiently than the wild-type. This demonstrates that the coordination of motor programs allows C. elegans to smoothly retract from a fungal noose and evade capture. Our results suggest that selective pressures imposed by predacious fungi have shaped the evolution of C. elegans escape behavior.

  8. Tectonic escape in the evolution of the continental crust

    Science.gov (United States)

    Burke, K.; Sengor, C.

    1986-01-01

    The continental crust originated by processes similar to those operating today and continents consist of material most of which originated long ago in arc-systems that have later been modified, especially at Andean margins and in continental collisions where crustal thickening is common. Collision-related strike-slip motion is a general process in continental evolution. Because buoyant continental (or arc) material generally moves during collision toward a nearby oceanic margin where less buoyant lithosphere crops out, the process of major strike-slip dominated motion toward a 'free-face' is called 'tectonic escape'. Tectonic escape is and has been an element in continental evolution throughout recorded earth-history. It promotes: (1) rifting and the formation of rift-basins with thinning of thickened crust; (2) pervasive strike-slip faulting late in orogenic history which breaks up mountain belts across strike and may juxtapose unrelated sectors in cross-section; (3) localized compressional mountains and related foreland-trough basins.

  9. NASA's Commercial Crew Program, The Next Step in U.S. Space Transportation

    Science.gov (United States)

    Mango, Edward J.; Thomas, Rayelle E.

    2013-01-01

    The Commercial Crew Program (CCP) is leading NASA's efforts to develop the next U.S. capability for crew transportation and rescue services to and from the International Space Station (ISS) by the mid-decade timeframe. The outcome of this capability is expected to stimulate and expand the U.S. space transportation industry. NASA is relying on its decades of human space flight experience to certify U.S. crewed vehicles to the ISS and is doing so in a two phase certification approach. NASA Certification will cover all aspects of a crew transportation system, including development, test, evaluation, and verification; program management and control; flight readiness certification; launch, landing, recovery, and mission operations; sustaining engineering and maintenance/upgrades. To ensure NASA crew safety, NASA Certification will validate technical and performance requirements, verify compliance with NASA requirements, validate the crew transportation system operates in appropriate environments, and quantify residual risks.

  10. Nutrititional Status Assessment of International Space Station Crew Members

    Science.gov (United States)

    Smith, S. M.; Zwart, S. R.; Block, G.; Rice, B. I.; Davis-Street, J. F.

    2005-01-01

    Defining optimal nutrient requirements is imperative to ensure crew health on long-duration space exploration missions. To date, nutrient requirement data have been extremely limited because of small sample sizes and difficulties associated with collecting biological samples. In this study, we examined changes in body composition, bone metabolism, hematology, general blood chemistry, and blood levels of selected vitamins and minerals after long-duration (128-195 d) space flight aboard the International Space Station. Crew members consumed an average of 80% of the recommended energy intakes, and on landing day their body weight had decreased (P=0.051). After flight, hematocrit was less, and serum femtin was greater than before flight (Pretinol binding protein, transthyretin, and albumin were not changed after flight suggests that the changes in iron metabolism may not be strictly due to an inflammatory response. Urinary 8- hydroxy-2'-deoxyguanosine concentration was greater and superoxide dismutase was less after flight, indicating that oxidative damage had increased (P<0.05). Despite the reported use of vitamin D supplements during flight, serum 25-hydroxyvitamin D was significantly decreased after flight (P<0.01). Bone resorption was increased after flight, as indicated by several urinary markers of bone resorption. Bone formation, assessed by serum concentration of bone-specific alkaline phosphatase, was elevated only in crew members who landed in Russia, probably because of the longer time lapse between landing and sample collection. These data provide evidence that bone loss, compromised vitamin D status, and oxidative damage remain critical concerns for long-duration space flight.

  11. Microbiology and Crew Medical Events on the International Space Station

    Science.gov (United States)

    Oubre, Cherie; Charvat, Jacqueline M.; Kadwa, Biniafer; Taiym, Wafa; Ott, C. Mark; Pierson, Duane; Baalen, Mary Van

    2014-01-01

    The closed environment of the International Space Station (ISS) creates an ideal environment for microbial growth. Previous studies have identified the ubiquitous nature of microorganisms throughout the space station environment. To ensure safety of the crew, microbial monitoring of air and surface within ISS began in December 2000 and continues to be monitored on a quarterly basis. Water monitoring began in 2009 when the potable water dispenser was installed on ISS. However, it is unknown if high microbial counts are associated with inflight medical events. The microbial counts are determined for the air, surface, and water samples collected during flight operations and samples are returned to the Microbiology laboratory at the Johnson Space Center for identification. Instances of microbial counts above the established microbial limit requirements were noted and compared inflight medical events (any non-injury event such as illness, rashes, etc.) that were reported during the same calendar-quarter. Data were analyzed using repeated measures logistic regression for the forty-one US astronauts flew on ISS between 2000 and 2012. In that time frame, instances of microbial counts being above established limits were found for 10 times for air samples, 22 times for surface samples and twice for water. Seventy-eight inflight medical events were reported among the astronauts. A three times greater risk of a medical event was found when microbial samples were found to be high (OR = 3.01; p =.007). Engineering controls, crew training, and strict microbial limits have been established to mitigate the crew medical events and environmental risks. Due to the timing issues of sampling and the samples return to earth, identification of particular microorganisms causing a particular inflight medical event is difficult. Further analyses are underway.

  12. First direct exposure to lunar material for Crew Reception personnel

    Science.gov (United States)

    1969-01-01

    The first direct exposure to lunar material for Crew Reception personnel probably happened late Friday, July 25, 1969. Terry Slezak (displaying moon dust on his left hand fingers), Manned Spacecraft Center (MSC) photographic technician, was removing film magazines from the first of two containers when the incident occurred. As he removed the plastic seal from Magazine S, one of the 70mm magazines taken during Apollo 11 Extravehicular Activity (EVA), it was apparent that the exterior of the cassette displayed traces of a black powdery substance. Apollo 11 Commander Neil Armstrong reported during the mission that he had retrieved a 70mm cassette which had dropped to the lunar surface.

  13. The influence of the noise environment on crew communications

    Science.gov (United States)

    Leverton, J. W.

    1978-01-01

    The noise environment and how it affects crew communications in helicopters is considered. The signal to noise (S/N) ratio at the microphone and the effect of the attenuation provided by the helmet is discussed. This shows that the most important aspect is the S/N ratio at the microphone, particularly when helmets with improved attenuation characteristics are considered. Evidence is presented which shows that in high noise environments, the system S/N ratio is well below that required and hence there is an urgent need to reduce the cabin noise levels and improve the microphone rejection properties. Emphasis is placed on environmental/acoustic considerations.

  14. Multipurpose Crew Restraints for Long Duration Space Flights

    Science.gov (United States)

    Whitmore, Mihriban; Baggerman, Susan; Ortiz, M. R.; Hua, L.; Sinnott, P.; Webb, L.

    2004-01-01

    With permanent human presence onboard the International Space Station (ISS), a crew will be living and working in microgravity, interfacing with their physical environment. Without optimum restraints and mobility aids (R&MA' s), the crewmembers may be handicapped for perfonning some of the on-orbit tasks. In addition to weightlessness, the confined nature of a spacecraft environment results in ergonomic challenges such as limited visibility and access to the activity area and may cause prolonged periods of unnatural postures. Thus, determining the right set of human factors requirements and providing an ergonomically designed environment are crucial to astronauts' well-being and productivity. The purpose of this project is to develop requirements and guidelines, and conceptual designs, for an ergonomically designed multi-purpose crew restraint. In order to achieve this goal, the project would involve development of functional and human factors requirements, design concept prototype development, analytical and computer modeling evaluations of concepts, two sets of micro gravity evaluations and preparation of an implementation plan. It is anticipated that developing functional and design requirements for a multi-purpose restraint would facilitate development of ergonomically designed restraints to accommodate the off-nominal but repetitive tasks, and minimize the performance degradation due to lack of optimum setup for onboard task performance. In addition, development of an ergonomically designed restraint concept prototype would allow verification and validation of the requirements defined. To date, we have identified "unique" tasks and areas of need, determine characteristics of "ideal" restraints, and solicit ideas for restraint and mobility aid concepts. Focus group meetings with representatives from training, safety, crew, human factors, engineering, payload developers, and analog environment representatives were key to assist in the development of a restraint

  15. Scanning transmission electron microscopy: Albert Crewe's vision and beyond.

    Science.gov (United States)

    Krivanek, Ondrej L; Chisholm, Matthew F; Murfitt, Matthew F; Dellby, Niklas

    2012-12-01

    Some four decades were needed to catch up with the vision that Albert Crewe and his group had for the scanning transmission electron microscope (STEM) in the nineteen sixties and seventies: attaining 0.5Å resolution, and identifying single atoms spectroscopically. With these goals now attained, STEM developments are turning toward new directions, such as rapid atomic resolution imaging and exploring atomic bonding and electronic properties of samples at atomic resolution. The accomplishments and the future challenges are reviewed and illustrated with practical examples.

  16. 45130-Drilling Crew First Enter into the International Drilling Market

    Institute of Scientific and Technical Information of China (English)

    Song Zhixian; Drilling

    1995-01-01

    @@ 45130-Drilling Crew subordinate to the Fourth Drilling Company of Zhongyuan Petroleum Exploration Bureau, won the two bids of risk exploration drilling projects, respectively for China Ltd. Co. of New Zealand Petroleum Exploration Company worked in the Dongtinghu Basin in 1992 and Amoco Orient Oil Co.worked in the Fuyang area, Anhui Province in November of 1993.According to the two contracts that have been signed, the two drilling wells were successfully completed,all drilling parameters are in accordance with the requirements of both contracts.

  17. [Style of communication between mission control centers and space crews].

    Science.gov (United States)

    Iusupova, A K; Gushchin, V I; Shved, D M; Cheveleva, L M

    2011-01-01

    The article deals with a pilot investigation into the audio communication of cosmonauts with ground controllers. The purpose was to verify in space flight the patterns and trends revealed in model tests of intergroup communication, and to pinpoint the signature of multinational crew communication with 2 national mission control centers (MCCs). The investigation employed authors' content-analysis adapted to the scenario of long-duration mission. The investigation resulted in a phenomenon of double-loop ground-orbit communication, divergence, difference in opinion predictable from the concept formulated by G.T.Beregovoi. Also, there was a notable difference of expressions used by controllers of 2 MCCs.

  18. Dynamic posture analysis of Spacelab-1 crew members.

    Science.gov (United States)

    Anderson, D J; Reschke, M F; Homick, J E; Werness, S A

    1986-01-01

    Dynamic posture testing was conducted on the science crew of the Spacelab-1 mission on a single axis linear motion platform. Tests took place in pre- and post-flight sessions lasting approximately 20 min each. The pre-flight tests were widely spaced over the several months prior to the mission while the post-flight tests were conducted over the first, second, fourth, and sixth days after landing. Two of the crew members were also tested on the day of landing. Consistent with previous postural testing conducted on flight crews, these crew members were able to complete simple postural tasks to an acceptable level even in the first few hours after landing. Our tests were designed to induce dynamic postural responses using a variety of stimuli and from these responses, evaluate subtle changes in the postural control system which had occurred over the duration of the flight. Periodic sampling post-flight allowed us to observe the time course of readaptation to terrestrial life. Our observations of hip and shoulder position, when subjected to careful analysis, indicated modification of the postural response from pre- to post-flight and that demonstrable adjustments in the dynamic control of their postural systems were taking place in the first few days after flight. For transient stimuli where the platform on which they were asked to stand quickly moved a few centimeters fore or aft then stopped, ballistic or open loop 'programs' would closely characterize the response. During these responses the desired target position was not always achieved and of equal importance not always properly corrected some 15 seconds after the platform ceased to move. The persistent observation was that the subjects had a much stronger dependence on visual stabilization post-flight than pre-flight. This was best illustrated by a slow or only partial recovery to an upward posture after a transient base-of-support movement with eyes open. Postural responses to persistent wideband pseudorandom

  19. American ASTP prime crew participate in photography mission briefing

    Science.gov (United States)

    1975-01-01

    The three American ASTP prime crew astronauts participate in a photography mission briefing in bldg 5 with Dr. Farouk El-Baz (wearing face mask) during Apollo Soyuz Test Project (ASTP) pre-flight activity at JSC. They are, left to right, Thomas P. Stafford, commander; Vance D. Brand, command module pilot; Dr. El-Baz; and Donald K. Slayton, docking module pilot. Dr. El-Baz is with the Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution. The face mask is to protect the crewmen from possible exposure to disease prior to launch time.

  20. Vaccination and timing influence SIV immune escape viral dynamics in vivo.

    Directory of Open Access Journals (Sweden)

    Liyen Loh

    2008-01-01

    Full Text Available CD8+ cytotoxic T lymphocytes (CTL can be effective at controlling HIV-1 in humans and SIV in macaques, but their utility is partly offset by mutational escape. The kinetics of CTL escape and reversion of escape mutant viruses upon transmission to MHC-mismatched hosts can help us understand CTL-mediated viral control and the fitness cost extracted by immune escape mutation. Traditional methods for following CTL escape and reversion are, however, insensitive to minor viral quasispecies. We developed sensitive quantitative real-time PCR assays to track the viral load of SIV Gag164-172 KP9 wild-type (WT and escape mutant (EM variants in pigtail macaques. Rapid outgrowth of EM virus occurs during the first few weeks of infection. However, the rate of escape plateaued soon after, revealing a prolonged persistence of WT viremia not detectable by standard cloning and sequencing methods. The rate of escape of KP9 correlated with levels of vaccine-primed KP9-specific CD8+ T cells present at that time. Similarly, when non-KP9 responder (lacking the restricting Mane-A*10 allele macaques were infected with SHIVmn229 stock containing a mixture of EM and WT virus, rapid reversion to WT was observed over the first 2 weeks following infection. However, the rate of reversion to WT slowed dramatically over the first month of infection. The serial quantitation of escape mutant viruses evolving during SIV infection shows that rapid dynamics of immune escape and reversion can be observed in early infection, particularly when CD8 T cells are primed by vaccination. However, these early rapid rates of escape and reversion are transient and followed by a significant slowing in these rates later during infection, highlighting that the rate of escape is significantly influenced by the timing of its occurrence.

  1. On the relative contributions of positive reinforcement and escape extinction in the treatment of food refusal.

    OpenAIRE

    Piazza, Cathleen C; Patel, Meeta R; Gulotta, Charles S; Sevin, Bari M; Layer, Stacy A

    2003-01-01

    We compared the effects of positive reinforcement alone, escape extinction alone, and positive reinforcement with escape extinction in the treatment of the food and fluid refusal of 4 children who had been diagnosed with a pediatric feeding disorder. Consumption did not increase when positive reinforcement was implemented alone. By contrast, consumption increased for all participants when escape extinction was implemented, independent of the presence or absence of positive reinforcement. Howe...

  2. Momentum versus extinction effects in the treatment of self-injurious escape behavior.

    OpenAIRE

    Zarcone, J R; Iwata, B A; Hughes, C.E; Vollmer, T R

    1993-01-01

    An individual's self-injurious escape behavior was treated using a high-probability instructional sequence with and without extinction. When presented alone, the high-probability sequence did not reduce self-injurious behavior. When escape extinction was implemented either alone or in combination with the high-probability sequence, self-injury decreased and compliance increased, suggesting that extinction may be a necessary component of the treatment for behavior problems maintained by escape.

  3. Characterization of escape times of Josephson junctions for signal detection.

    Science.gov (United States)

    Addesso, Paolo; Filatrella, Giovanni; Pierro, Vincenzo

    2012-01-01

    The measurement of the escape time of a Josephson junction might be used to detect the presence of a sinusoidal signal embedded in noise when use of standard signal processing tools can be prohibitive due to the extreme weakness of the source or to the huge amount of data. In this paper we show that the prescriptions for the experimental setup and some physical behaviors depend on the detection strategy. More specifically, by exploitation of the sample mean of escape times to perform detection, two resonant regions are identified. At low frequencies there is a stochastic resonance or activation phenomenon, while near the plasma frequency a geometric resonance appears. Furthermore, detection performance in the geometric resonance region is maximized at the prescribed value of the bias current. The naive sample mean detector is outperformed, in terms of error probability, by the optimal likelihood ratio test. The latter exhibits only geometric resonance, showing monotonically increasing performance as the bias current approaches the junction critical current. In this regime the escape times are vanishingly small and therefore performance is essentially limited by measurement electronics. The behavior of the likelihood ratio and sample mean detector for different values of incoming signal to noise ratio is discussed, and a relationship with the error probability is found. Detectors based on the likelihood ratio test could be employed also to estimate unknown parameters in the applied input signal. As a prototypical example we study the phase estimation problem of a sinusoidal current, which is accomplished by using the filter bank approach. Finally we show that for a physically feasible detector the performances are found to be very close to the Cramer-Rao theoretical bound. Applications might be found, for example, in some astronomical detection problems (where the all-sky gravitational and/or radio wave search for pulsars requires the analysis of nearly sinusoidal

  4. On the relative contributions of positive reinforcement and escape extinction in the treatment of food refusal.

    Science.gov (United States)

    Piazza, Cathleen C; Patel, Meeta R; Gulotta, Charles S; Sevin, Bari M; Layer, Stacy A

    2003-01-01

    We compared the effects of positive reinforcement alone, escape extinction alone, and positive reinforcement with escape extinction in the treatment of the food and fluid refusal of 4 children who had been diagnosed with a pediatric feeding disorder. Consumption did not increase when positive reinforcement was implemented alone. By contrast, consumption increased for all participants when escape extinction was implemented, independent of the presence or absence of positive reinforcement. However, the addition of positive reinforcement to escape extinction was associated with beneficial effects (e.g., greater decreases in negative vocalizations and inappropriate behavior) for some participants.

  5. Experiment for Development of Simple Escape Countermeasures for Frogs Falling into Concrete Canals

    Science.gov (United States)

    Watabe, Keiji; Mori, Atsushi; Koizumi, Noriyuki; Takemura, Takeshi; Park, Myeong Soo

    Three prototype escape countermeasures for frogs that can be easily installed in U-shaped canals with widths of 30-50 cm and depths of 30-50 cm were experimentally produced because frogs cannot escape from agricultural canals with deep concrete walls after falling into the canal. The differences of effectiveness of the 3 prototypes in places for the countermeasures (1 and 2) and flow conditions (dry and water running) were investigated for 2 frog species (Tokyo Daruma Pond Frog and Japanese Brown Frog). The brown frogs escaped from the canals more easily than the pond frogs. The brown frogs escaped regardless of their body size, but the small pond frogs escaped more easily than the large pond frogs. The prototype with slopes beside both canal walls and a net spread across the center line of the canal enabled frogs to escape from the canal more easily than the prototypes with only slopes or nets beside both canal walls. Increasing the number of places for the countermeasures enhanced frog escape. The differences in frog escape between dry canals and canals with water running were not significant. Therefore, the prototypes were confirmed sufficient as escape countermeasures that is inexpensive and can be easily placed in and removed from agricultural canals.

  6. Improving escape panel selectivity in Nephrops directed fisheries by actively stimulating fish behaviour

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Herrmann, Bent; Feekings, Jordan P.

    2016-01-01

    with it. To increase the efficiency of such panels, the contact probability needs to be improved. In this study, we investigate to what extent the efficiency of escape panels can be improved by actively stimulating the escape behaviour of fish. The performance of two identical panel sections was compared...... in a twin-trawl system, one with and one without a stimulation device. A new coupled analysis method was used to explicitly quantify the improvements in contact probability and release efficiency for the escape panel. The results demonstrate that by actively stimulating escape behaviour, the contact...

  7. Sharks modulate their escape behavior in response to predator size, speed and approach orientation.

    Science.gov (United States)

    Seamone, Scott; Blaine, Tristan; Higham, Timothy E

    2014-12-01

    Escape responses are often critical for surviving predator-prey interactions. Nevertheless, little is known about how predator size, speed and approach orientation impact escape performance, especially in larger prey that are primarily viewed as predators. We used realistic shark models to examine how altering predatory behavior and morphology (size, speed and approach orientation) influences escape behavior and performance in Squalus acanthias, a shark that is preyed upon by apex marine predators. Predator models induced C-start escape responses, and increasing the size and speed of the models triggered a more intense response (increased escape turning rate and acceleration). In addition, increased predator size resulted in greater responsiveness from the sharks. Among the responses, predator approach orientation had the most significant impact on escapes, such that the head-on approach, as compared to the tail-on approach, induced greater reaction distances and increased escape turning rate, speed and acceleration. Thus, the anterior binocular vision in sharks renders them less effective at detecting predators approaching from behind. However, it appears that sharks compensate by performing high-intensity escapes, likely induced by the lateral line system, or by a sudden visual flash of the predator entering their field of view. Our study reveals key aspects of escape behavior in sharks, highlighting the modulation of performance in response to predator approach.

  8. Crew Exploration Vehicle Potable Water System Verification Description

    Science.gov (United States)

    Tuan, George; Peterson, Laurie J.; Vega, Leticia M.

    2010-01-01

    A stored water system on the crew exploration vehicle (CEV) will supply the crew with potable water for: drinking and food rehydration, hygiene, medical needs, sublimation, and various contingency situations. The current baseline biocide for the stored water system is ionic silver, similar in composition to the biocide used to maintain the quality of the water, transferred from the orbiter to the International Space Station, stored in contingency water containers. In the CEV water system, a depletion of the ionic silver biocide is expected due to ionic silver-plating onto the surfaces of materials within the CEV water system, thus negating its effectiveness as a biocide. Because this may be the first time NASA is considering a stored water system for long-term missions that do not maintain a residual biocide, a team of experts in materials compatibility, biofilms and point-of-use filters, surface treatment and coatings, and biocides has been created to pinpoint concerns and perform the testing that will help alleviate concerns related to the CEV water system.

  9. Identification of Crew-Systems Interactions and Decision Related Trends

    Science.gov (United States)

    Jones, Sharon Monica; Evans, Joni K.; Reveley, Mary S.; Withrow, Colleen A.; Ancel, Ersin; Barr, Lawrence

    2013-01-01

    NASA Vehicle System Safety Technology (VSST) project management uses systems analysis to identify key issues and maintain a portfolio of research leading to potential solutions to its three identified technical challenges. Statistical data and published safety priority lists from academic, industry and other government agencies were reviewed and analyzed by NASA Aviation Safety Program (AvSP) systems analysis personnel to identify issues and future research needs related to one of VSST's technical challenges, Crew Decision Making (CDM). The data examined in the study were obtained from the National Transportation Safety Board (NTSB) Aviation Accident and Incident Data System, Federal Aviation Administration (FAA) Accident/Incident Data System and the NASA Aviation Safety Reporting System (ASRS). In addition, this report contains the results of a review of safety priority lists, information databases and other documented references pertaining to aviation crew systems issues and future research needs. The specific sources examined were: Commercial Aviation Safety Team (CAST) Safety Enhancements Reserved for Future Implementation (SERFIs), Flight Deck Automation Issues (FDAI) and NTSB Most Wanted List and Open Recommendations. Various automation issues taxonomies and priority lists pertaining to human factors, automation and flight design were combined to create a list of automation issues related to CDM.

  10. STS-114 Crew Interviews: 1. Eileen Collins 2. Wendy Lawrence

    Science.gov (United States)

    2005-01-01

    1) STS-114 Commander Eileen Collins emphasized her love for teaching, respect for teachers, and her plan to go back to teaching again someday. Her solid background in Math and Science, focus on her interests, with great support from her family, and great training and support during her career with the Air Force gave her confidence in pursuing her dream to become an astronaut. Commander Collins shares her thoughts on the Columbia, details the various flight operations and crew tasks that will take place during the mission and the importance of Shuttle missions to the International Space Station and space exploration. 2) STS-114 Mission Specialist Wendy Lawrence first dreamed of becoming an astronaut when she watched Neil Armstrong walk on the moon from their black and white TV set. She majored in Engineering and became a Navy pilot. She shares her thoughts on the Columbia, details her major role as the crew in charge of all the transfer operations; getting the MPLM unpacked and repacked; and the importance of Shuttle missions to the International Space Station and space exploration.

  11. Holographic Weapons Sight as Crew Optical Alignment Sight

    Science.gov (United States)

    Merancy, Nujoud; Dehmlow, Brian; Brazzel, Jack P.

    2011-01-01

    Crew Optical Alignment Sights (COAS) are used by spacecraft pilots to provide a visual reference to a target spacecraft for lateral relative position during rendezvous and docking operations. NASA s Orion vehicle, which is currently under development, has not included a COAS in favor of automated sensors, but the crew office has requested such a device be added for situational awareness and contingency support. The current Space Shuttle COAS was adopted from Apollo heritage, weighs several pounds, and is no longer available for procurement which would make re-use difficult. In response, a study was conducted to examine the possibility of converting a commercially available weapons sight to a COAS for the Orion spacecraft. The device used in this study was the XPS series Holographic Weapon Sight (HWS) procured from L-3 EOTech. This device was selected because the targeting reticule can subtend several degrees, and display a graphic pattern tailored to rendezvous and docking operations. Evaluations of the COAS were performed in both the Orion low-fidelity mockup and rendezvous simulations in the Reconfigurable Operational Cockpit (ROC) by crewmembers, rendezvous engineering experts, and flight controllers at Johnson Space Center. These evaluations determined that this unit s size and mounting options can support proper operation and that the reticule visual qualities are as good as or better than the current Space Shuttle COAS. The results positively indicate that the device could be used as a functional COAS and supports a low-cost technology conversion solution.

  12. STS-114: Crew Interviews 1. Andy Thomas 2. Steve Robinson

    Science.gov (United States)

    2005-01-01

    STS-114 Mission Specialists, Andy Thomas and Steve Robinson, are seen in this pre-flight interview. Andy Thomas begins by talking about his interest in spaceflight as a young boy growing up in Australia. He expresses that the chances of an Australian boy studying to eventually become an astronaut was very remote. His Mechanical Engineering Degree in Australia and a Doctorate enabled him to acquire unique skills to come to the United States to work for Lockheed Martin. On the topic of return to flight, he reflects on experiences that he had working with the Michael Anderson and Kalpana Chawla of the ill-fated Space Shuttle Columbia. He also talks about the safety of the Space Shuttle Discovery and repairs to its Thermal Protection system. He explains in detail the Logistics Flight (LF) 1, spacewalks, Multipurpose Logistics Module (MPLM) and the External Stowage Platform (ESP)-2. Steve Robinson expresses that he had many interests as a child and becoming an astronaut was one of them. He was fascinated with things that fly and wanted to find out how they flew. He also designed hang gliders as a teenager. He expresses how his family feels about the risky business of spaceflight. He talks about how the space shuttle discovery crew will remember the Columbia crew by including seven stars on their patch so that they can bring them into orbit and then back home. Robinson also talks about his primary job, and the spacewalks that he and Soichi Noguchi will be performing.

  13. STS-103 crew on Pad 39-B during TCDT activities

    Science.gov (United States)

    1999-01-01

    Taking a break during emergency egress training at Launch Pad 39B are (left to right) STS-103 Mission Specialists Jean-Frangois Clervoy of France, Claude Nicollier of Switzerland, Commander Curtis L. Brown Jr., Pilot Scott J. Kelly, and Mission Specialists John M. Grunsfeld (Ph.D.), C. Michael Foale (Ph.D.) and Steven L. Smith. Clervoy and Nicollier are with the European Space Agency. The training is part of Terminal Countdown Demonstration Test (TCDT) activities that also include opportunities to inspect the mission payloads in the orbiter's payload bay and simulated countdown exercises. STS-103 is a 'call-up' mission due to the need to replace and repair portions of the Hubble Space Telescope, including the gyroscopes that allow the telescope to point at stars, galaxies and planets. The STS-103 crew will be replacing a Fine Guidance Sensor, an older computer with a new enhanced model, an older data tape recorder with a solid-state digital recorder, a failed spare transmitter with a new one, and degraded insulation on the telescope with new thermal insulation. The crew will also install a Battery Voltage/Temperature Improvement Kit to protect the spacecraft batteries from overcharging and overheating when the telescope goes into a safe mode. Four EVA's are planned to make the necessary repairs and replacements on the telescope. The mission is targeted for launch Dec. 6 at 2:37 a.m. EST.

  14. The structure of spider's web fast escaping sets

    CERN Document Server

    Osborne, J W

    2010-01-01

    Building on recent work by Rippon and Stallard, we explore the intricate structure of the spider's web fast escaping sets associated with certain transcendental entire functions. Our results are expressed in terms of the components of the complement of the set (the 'holes' in the web). We describe the topology of such components and give a characterisation of their possible orbits under iteration. We show that there are uncountably many components having each of a number of orbit types, and we prove that components with bounded orbits are quasiconformally homeomorphic to components of the filled Julia set of a polynomial. We also show that there are singleton periodic components and that these are dense in the Julia set.

  15. Bacillus cereus immune escape: a journey within macrophages.

    Science.gov (United States)

    Tran, Seav-Ly; Ramarao, Nalini

    2013-10-01

    During bacterial infection, professional phagocytes are attracted to the site of infection, where they constitute a first line of host cell defense. Their function is to engulf and destroy the pathogens. Thus, bacteria must withstand the bactericidal activity of professional phagocytes, including macrophages to counteract the host immune system. Bacillus cereus infections are characterized by bacteremia despite the accumulation of inflammatory cells at the site of infection. This implies that the bacteria have developed means of resisting the host immune system. Bacillus cereus spores survive, germinate, and multiply in contact with macrophages, eventually producing toxins that kill these cells. However, the exact mechanism by which B. cereus evades immune attack remains unclear. This review addresses the interaction between B. cereus and macrophages, highlighting, in particular, the ways in which the bacteria escape the microbicidal activities of professional phagocytes.

  16. Escape and avoidance learning in the earthworm Eisenia hortensis

    Directory of Open Access Journals (Sweden)

    W. Jeffrey Wilson

    2014-01-01

    Full Text Available Interest in instrumental learning in earthworms dates back to 1912 when Yerkes concluded that they can learn a spatial discrimination in a T-maze. Rosenkoetter and Boice determined in the 1970s that the “learning” that Yerkes observed was probably chemotaxis and not learning at all. We examined a different form of instrumental learning: the ability to learn both to escape and to avoid an aversive stimulus. Freely moving “master” worms could turn off an aversive white light by increasing their movement; the behavior of yoked controls had no effect on the light. We demonstrate that in as few as 12 trials the behavior of the master worms comes under the control of this contingency.

  17. Escaping Antiangiogenic Therapy: Strategies Employed by Cancer Cells

    Directory of Open Access Journals (Sweden)

    Mauricio P. Pinto

    2016-09-01

    Full Text Available Tumor angiogenesis is widely recognized as one of the “hallmarks of cancer”. Consequently, during the last decades the development and testing of commercial angiogenic inhibitors has been a central focus for both basic and clinical cancer research. While antiangiogenic drugs are now incorporated into standard clinical practice, as with all cancer therapies, tumors can eventually become resistant by employing a variety of strategies to receive nutrients and oxygen in the event of therapeutic assault. Herein, we concentrate and review in detail three of the principal mechanisms of antiangiogenic therapy escape: (1 upregulation of compensatory/alternative pathways for angiogenesis; (2 vasculogenic mimicry; and (3 vessel co-option. We suggest that an understanding of how a cancer cell adapts to antiangiogenic therapy may also parallel the mechanisms employed in the bourgeoning tumor and isolated metastatic cells delivering responsible for residual disease. Finally, we speculate on strategies to adapt antiangiogenic therapy for future clinical uses.

  18. On Escaping a Galaxy Cluster in an Accelerating Universe

    CERN Document Server

    Stark, Alejo; Gifford, Daniel

    2016-01-01

    We derive the escape velocity profile for an Einasto density field in an accelerating universe and demonstrate its physical viability by comparing theoretical expectations to both light-cone data generated from N-body simulations and archival data on 20 galaxy clusters. We demonstrate that the projection function ($g(\\beta )$) is deemed physically viable only for the theoretical expectation that includes a cosmology-dependent term. Using simulations, we show that the inferred velocity anisotropy is more than 6{\\sigma} away from the expected value for the theoretical profile that ignores the acceleration of the universe. In the archival data, we constrain the average velocity anisotropy parameter of a sample of 20 clusters to be $\\beta ={0.248}_{-0.360}^{+0.164}$ at the 68% confidence level. Lastly, we briefly discuss how our analytic model may be used as a novel cosmological probe based on galaxy clusters.

  19. An Introduction to Survival, Evasion, Resistance, and Escape (SERE) Medicine.

    Science.gov (United States)

    Smith, Michael B

    2013-01-01

    When an individual finds himself/herself in a survival, evasion, resistance, or escape (SERE) scenario, the ability to treat injuries/illnesses can be the difference between life and death. SERE schools are responsible for preparing military members for these situations, but the concept of SERE medicine is not particularly well defined. To provide a comprehensive working description of SERE medicine, operational and training components were examined. Evidence suggests that SERE medicine is diverse, injury/illness patterns are situationally dependent, and treatment options often differ from conventional clinical medicine. Ideally, medical lessons taught in SERE training are based on actual documented events. Unfortunately, the existing body of literature is dated and does not appear to be expanding. In this article, four distinct facets of SERE medicine are presented to establish a basis for future discussion and research. Recommendations to improve SERE medical curricula and data-gathering processes are also provided.

  20. Will 3552 Don Quixote escape from the Solar System?

    Directory of Open Access Journals (Sweden)

    Suryadi Siregar

    2011-05-01

    Full Text Available Asteroid 1983 SA, well known as 3552 Don Quixote, is one of Near Earth Asteroids (NEAs which is the most probable candidate for the cometary origin, or otherwise as Jupiter-Family-Comets (JFCs. The aim of this study is to investigate the possibility of 3552 Don Quixote to be ejected from the Solar System. This paper presents an orbital evolution of 100 hypothetical asteroids generated by cloning 3552 Don Quixote. Investigation of its orbital evolution is conducted by using the SWIFT subroutine package, where the gravitational perturbations of eight major planets in the Solar System are considered. Over very short time scales (220 kyr relative to the Solar System life time (10 Gyr, the asteroid 3552 Don Quixote gave an example of chaotic motion that can cause asteroid to move outward and may be followed by escaping from the Solar System. Probability of ejection within the 220 kyr time scale is 50%.

  1. Escape of Mycobacterium tuberculosis from oxidative killing by neutrophils.

    Science.gov (United States)

    Corleis, Björn; Korbel, Daniel; Wilson, Robert; Bylund, Johan; Chee, Ronnie; Schaible, Ulrich E

    2012-07-01

    Neutrophils enter sites of infection, where they can eliminate pathogenic bacteria in an oxidative manner. Despite their predominance in active tuberculosis lesions, the function of neutrophils in this important human infection is still highly controversial. We observed that virulent Mycobacterium tuberculosis survived inside human neutrophils despite prompt activation of these defence cells' microbicidal effectors. Survival of M. tuberculosis was accompanied by necrotic cell death of infected neutrophils. Necrotic cell death entirely depended on radical oxygen species production since chronic granulomatous disease neutrophils were protected from M. tuberculosis-triggered necrosis. More, importantly, the M. tuberculosis ΔRD1 mutant failed to induce neutrophil necrosis rendering this strain susceptible to radical oxygen species-mediated killing. We conclude that this virulence function is instrumental for M. tuberculosis to escape killing by neutrophils and contributes to pathogenesis in tuberculosis.

  2. Novel Anti-Melanoma Immunotherapies: Disarming Tumor Escape Mechanisms

    Directory of Open Access Journals (Sweden)

    Sivan Sapoznik

    2012-01-01

    Full Text Available The immune system fights cancer and sometimes temporarily eliminates it or reaches an equilibrium stage of tumor growth. However, continuous immunological pressure also selects poorly immunogenic tumor variants that eventually escape the immune control system. Here, we focus on metastatic melanoma, a highly immunogenic tumor, and on anti-melanoma immunotherapies, which recently, especially following the FDA approval of Ipilimumab, gained interest from drug development companies. We describe new immunomodulatory approaches currently in the development pipeline, focus on the novel CEACAM1 immune checkpoint, and compare its potential to the extensively described targets, CTLA4 and PD1. This paper combines multi-disciplinary approaches and describes anti-melanoma immunotherapies from molecular, medical, and business angles.

  3. Fast Escape from Quantum Mazes in Integrated Photonics

    CERN Document Server

    Caruso, Filippo; Ciriolo, Anna Gabriella; Sciarrino, Fabio; Osellame, Roberto

    2015-01-01

    Escaping from a complex maze, by exploring different paths with several decision-making branches in order to reach the exit, has always been a very challenging and fascinating task. Wave field and quantum objects may explore a complex structure in parallel by interference effects, but without necessarily leading to more efficient transport. Here, inspired by recent observations in biological energy transport phenomena, we demonstrate how a quantum walker can efficiently reach the output of a maze by partially suppressing the presence of interference. In particular, we show theoretically an unprecedented improvement in transport efficiency for increasing maze size with respect to purely quantum and classical approaches. In addition, we investigate experimentally these hybrid transport phenomena, by mapping the maze problem in an integrated waveguide array, probed by coherent light, hence successfully testing our theoretical results. These achievements may lead towards future bio-inspired photonics technologies...

  4. Integrating Human Factors into Crew Exploration Vehicle Design

    Science.gov (United States)

    Whitmore, Mihriban; Baggerman, Susan; Campbell, paul

    2007-01-01

    With NASA's new Vision for Exploration to send humans beyond Earth orbit, it is critical to consider the human as a system that demands early and continuous user involvement, and an iterative prototype/test/redesign process. Addressing human-system interface issues early on can be very cost effective even cost reducing when performed early in the design and development cycle. To achieve this goal within Crew Exploration Vehicle (CEV) Project Office, human engineering (HE) team is formed. Key tasks are to apply HE requirements and guidelines to hardware/software, and provide HE design, analysis and evaluation of crew interfaces. Initial activities included many practice-orientated evaluations using low-fidelity CEV mock-ups. What follows is a description of such evaluations that focused on a HE requirement regarding Net Habitable Volume (NHV). NHV is defined as the total remaining pressurized volume available to on-orbit crew after accounting for the loss of volume due to deployed hardware and structural inefficiencies which decrease functional volume. The goal of the NHV evaluations was to develop requirements providing sufficient CEV NHV for crewmembers to live and perform tasks in support of mission goals. Efforts included development of a standard NHV calculation method using computer models and physical mockups, and crew/ stakeholder evaluations. Nine stakeholders and ten crewmembers participated in the unsuited evaluations. Six crewmembers also participated in a suited evaluation. The mock-up was outfitted with volumetric representation of sub-systems such as seats, and stowage bags. Thirteen scenarios were developed to represent mission/crew tasks and considered to be primary volume drivers (e.g., suit donning) for the CEV. Unsuited evaluations included a structured walkthrough of these tasks. Suited evaluations included timed donning of the existing launch and entry suit to simulate a contingency scenario followed by doffing/ stowing of the suits. All mockup

  5. Escaped and Trapped Emission of Organic Light-Emitting Diodes

    Institute of Scientific and Technical Information of China (English)

    LIANG Shi-Xiong; WU Zhao-Xin; ZHAO Xuan-Ke; HOU Xun

    2012-01-01

    By locating the emitters around the first and second antinode of the metal electrode, the escaped and trapped emission of small molecule based bottom emission organic light-emitting diodes is investigated by using an integrating sphere, a fiber spectrometer and a glass hemisphere. It is found that the external coupling ratio by locating the emitters at the second antinode (at a distance of 220 nm from the cathode) is 70%, which is higher than that of an emitter at the first antinode (60 nm from the cathode) in theory and experiment. Extending the "half-space" dipole model by taking the dipole radiation pattern into account, we also calculate the optical coupling efficiency for the emitter at both the first and second antinode. Our experimental and theoretical results will benefit the optimization of device structures for the higher out-coupling efficiency.%By locating the emitters around the first and second antinode of the metal electrode,the escaped and trapped emission of small molecule based bottom emission organic light-emitting diodes is investigated by using an integrating sphere,a fiber spectrometer and a glass hemisphere.It is found that the external coupling ratio by locating the emitters at the second antinode (at a distance of 220 nm from the cathode) is 70%,which is higher than that of an emitter at the first antinode (60nm from the cathode) in theory and experiment.Extending the "half-space" dipole model by taking the dipole radiation pattern into account,we also calculate the optical coupling efficiency for the emitter at both the first and second antinode.Our experimental and theoretical results will benefit the optimization of device structures for the higher out-coupling efficiency.

  6. ESCAP holds expert group meeting on population issues facing adolescents.

    Science.gov (United States)

    1997-01-01

    This article summarizes the activities at the ESCAP Population Division Expert Group Meeting on Adolescents that was held during September-October 1997 in Bangkok, Thailand. The meeting was a follow-up to the 1994 International Conference on Population and Development (ICPD). The meeting considered 1) the ICPD recommendations; 2) the recommendations contained in the Jakarta Plan of Action on Human Resource Development; and 3) the Proposals for Action on Human Resources Development for Youth in Asia and the Pacific. Participants included about 25 people from Australia, Bangladesh, China, India, Indonesia, Philippines, Sri Lanka, and Thailand. The conference relied on 8 invited experts, two resource persons, advisors from the UNFPA Country Support Team for East and Southeast Asia, and representatives of UNFPA, the Population Council, and the East-West Center. A concern was the declining age of menarche of girls in the ESCAP region and the increasing age of marriage. During the time of menarche and marriage, girls are migrating and moving away from their family and community in rural areas. Family structure and relationships are changing. Increases are observed in adolescent premarital sexual activity, the incidence of sexually transmitted diseases, substance abuse, teenage pregnancy, and abortion. The mass media and information technologies have both a positive and a negative influence on adolescents. Parent-child communication exchanges and teacher-student exchanges are "less than ideal." Old traditions and practices change slower than people change. Boys and girls are affected differently by the sociocultural and economic environment. The societal norms set expectations for behavior that may conflict with individual beliefs and practices. Changes brought by globalization and rapid economic growth provide greater opportunity for young girls and women to obtain employment and autonomy.

  7. RpoS controls the Vibrio cholerae mucosal escape response.

    Directory of Open Access Journals (Sweden)

    Alex Toftgaard Nielsen

    2006-10-01

    Full Text Available Vibrio cholerae causes a severe diarrhoeal disease by secreting a toxin during colonization of the epithelium in the small intestine. Whereas the initial steps of the infectious process have been intensively studied, the last phases have received little attention. Confocal microscopy of V. cholerae O1-infected rabbit ileal loops captured a distinctive stage in the infectious process: 12 h post-inoculation, bacteria detach from the epithelial surface and move into the fluid-filled lumen. Designated the "mucosal escape response," this phenomenon requires RpoS, the stationary phase alternative sigma factor. Quantitative in vivo localization assays corroborated the rpoS phenotype and showed that it also requires HapR. Expression profiling of bacteria isolated from ileal loop fluid and mucus demonstrated a significant RpoS-dependent upregulation of many chemotaxis and motility genes coincident with the emigration of bacteria from the epithelial surface. In stationary phase cultures, RpoS was also required for upregulation of chemotaxis and motility genes, for production of flagella, and for movement of bacteria across low nutrient swarm plates. The hapR mutant produced near-normal numbers of flagellated cells, but was significantly less motile than the wild-type parent. During in vitro growth under virulence-inducing conditions, the rpoS mutant produced 10- to 100-fold more cholera toxin than the wild-type parent. Although the rpoS mutant caused only a small over-expression of the genes encoding cholera toxin in the ileal loop, it resulted in a 30% increase in fluid accumulation compared to the wild-type. Together, these results show that the mucosal escape response is orchestrated by an RpoS-dependent genetic program that activates chemotaxis and motility functions. This may furthermore coincide with reduced virulence gene expression, thus preparing the organism for the next stage in its life cycle.

  8. Initiating a watch list for Ebola virus antibody escape mutations

    Directory of Open Access Journals (Sweden)

    Craig R. Miller

    2016-02-01

    Full Text Available The 2014 Ebola virus (EBOV outbreak in West Africa is the largest in recorded history and resulted in over 11,000 deaths. It is essential that strategies for treatment and containment be developed to avoid future epidemics of this magnitude. With the development of vaccines and antibody-based therapies using the envelope glycoprotein (GP of the 1976 Mayinga strain, one important strategy is to anticipate how the evolution of EBOV might compromise these efforts. In this study we have initiated a watch list of potential antibody escape mutations of EBOV by modeling interactions between GP and the antibody KZ52. The watch list was generated using molecular modeling to estimate stability changes due to mutation. Every possible mutation of GP was considered and the list was generated from those that are predicted to disrupt GP-KZ52 binding but not to disrupt the ability of GP to fold and to form trimers. The resulting watch list contains 34 mutations (one of which has already been seen in humans at six sites in the GP2 subunit. Should mutations from the watch list appear and spread during an epidemic, it warrants attention as these mutations may reflect an evolutionary response from the virus that could reduce the effectiveness of interventions such as vaccination. However, this watch list is incomplete and emphasizes the need for more experimental structures of EBOV interacting with antibodies in order to expand the watch list to other epitopes. We hope that this work provokes experimental research on evolutionary escape in both Ebola and other viral pathogens.

  9. Phenotypic mismatches reveal escape from arms-race coevolution.

    Directory of Open Access Journals (Sweden)

    Charles T Hanifin

    2008-03-01

    Full Text Available Because coevolution takes place across a broad scale of time and space, it is virtually impossible to understand its dynamics and trajectories by studying a single pair of interacting populations at one time. Comparing populations across a range of an interaction, especially for long-lived species, can provide insight into these features of coevolution by sampling across a diverse set of conditions and histories. We used measures of prey traits (tetrodotoxin toxicity in newts and predator traits (tetrodotoxin resistance of snakes to assess the degree of phenotypic mismatch across the range of their coevolutionary interaction. Geographic patterns of phenotypic exaggeration were similar in prey and predators, with most phenotypically elevated localities occurring along the central Oregon coast and central California. Contrary to expectations, however, these areas of elevated traits did not coincide with the most intense coevolutionary selection. Measures of functional trait mismatch revealed that over one-third of sampled localities were so mismatched that reciprocal selection could not occur given current trait distributions. Estimates of current locality-specific interaction selection gradients confirmed this interpretation. In every case of mismatch, predators were "ahead" of prey in the arms race; the converse escape of prey was never observed. The emergent pattern suggests a dynamic in which interacting species experience reciprocal selection that drives arms-race escalation of both prey and predator phenotypes at a subset of localities across the interaction. This coadaptation proceeds until the evolution of extreme phenotypes by predators, through genes of large effect, allows snakes to, at least temporarily, escape the arms race.

  10. Phenotypic mismatches reveal escape from arms-race coevolution.

    Science.gov (United States)

    Hanifin, Charles T; Brodie, Edmund D; Brodie, Edmund D

    2008-03-11

    Because coevolution takes place across a broad scale of time and space, it is virtually impossible to understand its dynamics and trajectories by studying a single pair of interacting populations at one time. Comparing populations across a range of an interaction, especially for long-lived species, can provide insight into these features of coevolution by sampling across a diverse set of conditions and histories. We used measures of prey traits (tetrodotoxin toxicity in newts) and predator traits (tetrodotoxin resistance of snakes) to assess the degree of phenotypic mismatch across the range of their coevolutionary interaction. Geographic patterns of phenotypic exaggeration were similar in prey and predators, with most phenotypically elevated localities occurring along the central Oregon coast and central California. Contrary to expectations, however, these areas of elevated traits did not coincide with the most intense coevolutionary selection. Measures of functional trait mismatch revealed that over one-third of sampled localities were so mismatched that reciprocal selection could not occur given current trait distributions. Estimates of current locality-specific interaction selection gradients confirmed this interpretation. In every case of mismatch, predators were "ahead" of prey in the arms race; the converse escape of prey was never observed. The emergent pattern suggests a dynamic in which interacting species experience reciprocal selection that drives arms-race escalation of both prey and predator phenotypes at a subset of localities across the interaction. This coadaptation proceeds until the evolution of extreme phenotypes by predators, through genes of large effect, allows snakes to, at least temporarily, escape the arms race.

  11. Whole-body volume regulation and escape from antidiuresis.

    Science.gov (United States)

    Verbalis, Joseph G

    2006-07-01

    Both individual cells and organs regulate their volume in response to sustained hypo-osmolality via solute and water losses. Similar processes occur in the whole body to regulate the volumes of extracellular fluid (ECF) and intravascular spaces toward normal levels. Body water losses occur via the phenomena "escape from antidiuresis"; solute losses occur through the secondary natriuresis induced by water retention. As a result of resistance to arginine vasopressin (AVP) signaling, escape from antidiuresis is caused by downregulation of kidney aquaporin-2 expression despite high AVP plasma levels. Recent data have implicated downregulation of vasopressin V2R as a potential mechanism of resistance, and suggest that this may be a result of decreased intrarenal angiotensin II signaling in combination with increased intrarenal nitric oxide and prostaglandin E2 signaling. The natriuresis that results in volume regulation of the ECF and vascular spaces is the result of intrarenal hemodynamic changes produced by volume expansion, but the degree to which these effects are modulated by aldosterone secretion and the activity of distal sodium cotransporters and channels remains to be elucidated. The clinical implication of these volume-regulatory processes is that the chronic hyponatremic state is one of water retention and solute losses from intracellular fluid and ECF compartments. The degree to which solute losses versus water retention contribute to hyponatremia will vary in association with many factors, including the etiology of the hyponatremia, the rapidity of development of the hyponatremia, the chronicity of the hyponatremia, the volume of daily water loading, and individual variability. Understanding these volume-regulatory processes allows a better understanding of many aspects of the conundrum of patients with "clinical euvolemia" and dilutional hyponatremia from AVP-induced water retention.

  12. Development of Countermeasures to Aid Functional Egress from the Crew Exploration Vehicle Following Long Duration Spaceflight

    Science.gov (United States)

    Mulavara, Ajitkumar; Fiedler, Matthew; Kofman, Igor; Fisher, Elizabeth; Wood, Scott; Serrador, Jorge; Peters, Brian; Cohen, Helen; Reschke, Millard; Bloomberg, Jacob

    2009-01-01

    Astronauts experience disturbances in sensorimotor function following their return to Earth due to adaptive responses that occur during exposure to the microgravity conditions of space flight. As part of the Crew Exploration Vehicle design requirements, the crewmember adapted to the microgravity state may need to egress the vehicle within a few minutes for safety and operational reasons in various sea state conditions following a water landing. The act of emergency egress includes and is not limited to rapid motor control tasks (including both fine motor such as object manipulation and gross motor such as opening a hatch) and visual acuity tasks while maintaining spatial orientation and postural stability in time to escape safely. Exposure to even low frequency motions (0.2-2.0 Hz) induced by sea conditions surrounding a vessel can cause significant fine and gross motor control problems affecting critical functions. These motion frequencies coupled with the varying sea state conditions (frequencies ranging from 0.125-0.5 Hz) cause performance deficits by affecting the efficacy of motor and visual acuity dependent skills in tasks critical to emergency egress activities such as visual monitoring of displays, actuating discrete controls, operating auxiliary equipment and communicating with Mission Control and recovery teams. Thus, during exploration class missions the sensorimotor disturbances due to the crewmember's adaptation to microgravity may lead to disruption in the ability to maintain postural stability and perform functional egress tasks during the initial introduction to the Earth's gravitational environment. At present, the functional implication of the interactions between a debilitated crewmember during readaptation to Earth s gravity and the environmental constraints imposed by a water landing scenario is not defined and no operational countermeasure has been implemented to mitigate this risk. Stochastic resonance (SR) is a mechanism whereby noise can

  13. Don't Rock the Boat : How Antiphase Crew Coordination Affects Rowing

    NARCIS (Netherlands)

    de Brouwer, Anouk J.; de Poel, Harjo J.; Hofmijster, Mathijs J.

    2013-01-01

    It is generally accepted that crew rowing requires perfect synchronization between the movements of the rowers. However, a long-standing and somewhat counterintuitive idea is that out-of-phase crew rowing might have benefits over in-phase (i.e., synchronous) rowing. In synchronous rowing, 5 to 6% of

  14. 76 FR 9806 - Agency Information Collection Activities: Passenger List/Crew List (CBP Form I-418)

    Science.gov (United States)

    2011-02-22

    ... List (CBP Form I-418) AGENCY: U.S. Customs and Border Protection, Department of Homeland Security... review and approval in accordance with the Paperwork Reduction Act: Passenger List/Crew List (CBP Form I... forms of information. Title: Passenger List/Crew List. OMB Number: 1651-0103. Form Number: CBP Form...

  15. 77 FR 2561 - Agency Information Collection Activities: Passenger List/Crew List (CBP Form I-418)

    Science.gov (United States)

    2012-01-18

    ... List (CBP Form I-418) AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland Security... concerning the Passenger List/Crew List (CBP Form I-418). This request for comment is being made pursuant to...: Passenger List/Crew List. OMB Number: 1651-0103. Form Number: CBP Form I-418. Abstract: CBP Form I-418...

  16. 78 FR 26648 - Agency Information Collection Activities: Passenger List/Crew List (CBP Form I-418)

    Science.gov (United States)

    2013-05-07

    ... List (CBP Form I-418) AGENCY: U.S. Customs and Border Protection (CBP), Department of Homeland Security... concerning the Passenger List/Crew List (CBP Form I-418). This request for comment is being made pursuant to...: Passenger List/Crew List. OMB Number: 1651-0103. Form Number: CBP Form I-418. Abstract: CBP Form I-418...

  17. 49 CFR 230.65 - Steam blocking view of engine crew.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Leaks § 230.65 Steam blocking view of engine crew. The steam locomotive owner and/or... 49 Transportation 4 2010-10-01 2010-10-01 false Steam blocking view of engine crew. 230.65...

  18. More explicit communication after classroom-based crew resource management training: results of a pragmatic trial.

    NARCIS (Netherlands)

    Verbeek-van Noord, I.; Bruijne, M.C. de; Twisk, J.W.R.; Dyck, C. van; Wagner, C.

    2015-01-01

    Rationale, aims and objectives: Aviation-based crew resource management trainings to optimize non-technical skills among professionals are often suggested for health care as a way to increase patient safety. Our aim was to evaluate the effect of a 2-day classroom-based crew resource management (CRM)

  19. Spoon Distance Fading with and without Escape Extinction as Treatment for Food Refusal

    Science.gov (United States)

    Rivas, Kristi D.; Piazza, Cathleen C.; Patel, Meeta R.; Bachmeyer, Melanie H.

    2010-01-01

    Little is known about the characteristics of meals that serve as motivating operations (MOs) for escape behavior. In the current investigation, we showed that the distance at which a therapist held a spoon from a child's lips served as an MO for escape behavior. Based on these results, we implemented spoon distance fading, compared fading with and…

  20. Hepatitis A Virus Vaccine Escape Variants and Potential New Serotype Emergence

    Science.gov (United States)

    Pérez-Sautu, Unai; Costafreda, M. Isabel; Caylà, Joan; Tortajada, Cecilia; Lite, Josep; Bosch, Albert

    2011-01-01

    Six hepatitis A virus antigenic variants that likely escaped the protective effect of available vaccines were isolated, mostly from men who have sex with men. The need to complete the proper vaccination schedules is critical, particularly in the immunocompromised population, to prevent the emergence of vaccine-escaping variants. PMID:21470474

  1. Computer Self-Efficacy, Competitive Anxiety and Flow State: Escaping from Firing Online Game

    Science.gov (United States)

    Hong, Jon-Chao; Pei-Yu, Chiu; Shih, Hsiao-Feng; Lin, Pei-Shin; Hong, Jon-Chao

    2012-01-01

    Flow state in game playing affected by computer self-efficacy and game competitive anxiety was studied. In order to examine the effect of those constructs with high competition, this study select "Escaping from firing online game" which require college students to escape from fire and rescue people and eliminate the fire damage along the way of…

  2. Treatment of Escape-Maintained Behavior with Positive Reinforcement: The Role of Reinforcement Contingency and Density

    Science.gov (United States)

    Ingvarsson, Einar T.; Hanley, Gregory P.; Welter, Katherine M.

    2009-01-01

    Functional analyses suggested that the disruptive behavior of three preschool children was maintained by escape from demands. While keeping the escape contingency intact, we conducted (a) a density analysis in which the children earned preferred items for task completion according to two schedules that varied in reinforcement density, and (b) a…

  3. The Effects of Fixed-Time Escape on Inappropriate and Appropriate Classroom Behavior

    Science.gov (United States)

    Waller, Rachael D.; Higbee, Thomas S.

    2010-01-01

    Few studies have explored the effects of fixed-time (FT) reinforcement on escape-maintained behavior of students in a classroom setting. We measured the effects of an FT schedule on the disruptive and appropriate academic behaviors of 2 junior high students in a public school setting. Results demonstrated that FT escape from tasks resulted in a…

  4. Competing Contingencies for Escape Behavior: Effects of Negative Reinforcement Magnitude and Quality

    Science.gov (United States)

    Hammond, Jennifer L.

    2009-01-01

    Previous research has shown that problem behavior maintained by social-negative reinforcement can be treated without escape extinction by enhancing the quality of positive reinforcement for an appropriate alternative response such as compliance. By contrast, negative reinforcement (escape) for compliance generally has been ineffective in the…

  5. Hepatitis A Virus Vaccine Escape Variants and Potential New Serotype Emergence

    OpenAIRE

    Pérez-Sautu, Unai; Costafreda, M. Isabel; Caylà, Joan; Tortajada, Cecilia; Lite, Josep; Bosch, Albert; Pintó, Rosa M.

    2011-01-01

    Six hepatitis A virus antigenic variants that likely escaped the protective effect of available vaccines were isolated, mostly from men who have sex with men. The need to complete the proper vaccination schedules is critical, particularly in the immunocompromised population, to prevent the emergence of vaccine-escaping variants.

  6. Identification of genes escaping X inactivation by allelic expression analysis in a novel hybrid mouse model.

    Science.gov (United States)

    Berletch, Joel B; Ma, Wenxiu; Yang, Fan; Shendure, Jay; Noble, William S; Disteche, Christine M; Deng, Xinxian

    2015-12-01

    X chromosome inactivation (XCI) is a female-specific mechanism that serves to balance gene dosage between the sexes whereby one X chromosome in females is inactivated during early development. Despite this silencing, a small portion of genes escape inactivation and remain expressed from the inactive X (Xi). Little is known about the distribution of escape from XCI in different tissues in vivo and about the mechanisms that control tissue-specific differences. Using a new binomial model in conjunction with a mouse model with identifiable alleles and skewed X inactivation we are able to survey genes that escape XCI in vivo. We show that escape from X inactivation can be a common feature of some genes, whereas others escape in a tissue specific manner. Furthermore, we characterize the chromatin environment of escape genes and show that expression from the Xi correlates with factors associated with open chromatin and that CTCF co-localizes with escape genes. Here, we provide a detailed description of the experimental design and data analysis pipeline we used to assay allele-specific expression and epigenetic characteristics of genes escaping X inactivation. The data is publicly available through the GEO database under ascension numbers GSM1014171, GSE44255, and GSE59779. Interpretation and discussion of these data are included in a previously published study (Berletch et al., 2015) [1].

  7. Psychosocial issues affecting crews during long-duration international space missions

    Science.gov (United States)

    Kanas, N.

    1998-01-01

    Psychosocial issues can negatively impact on crew performance and morale during long-duration international space missions. Major psychosocial factors that have been described in anecdotal reports from space and in studies from analog situations on Earth include: 1) crew heterogeneity due to gender differences, cultural issues, and work experiences and motivations; 2) language and dialect variations; and 3) task versus supportive leadership roles. All of these factors can lead to negative sequelae, such as intra-crew tension and cohesion disruptions. Specific sequelae that can result from single factors include subgrouping and scapegoating due to crew heterogeneity; miscommunication due to major or subtle language differences; and role confusion, competition, and status leveling due to inappropriate leadership role definition. It is time to conduct research exploring the impact of these psychosocial factors and their sequelae on space crews during actual long-duration international space missions.

  8. Display Techniques for Advanced Crew Stations (DTACS). Phase 1. Display Techniques Study.

    Science.gov (United States)

    1984-03-01

    34" " """- " -"" "-""’ " * - " ." " " -"~ ’ " ..... . . .. . . . . STRI PU4HT FEGA RADA SITE Figure 14. Intercept Mission BMW~ AIR.TOAIR I? L A -W PIGHTS"GCAOUNO RADAR SITE % Figure 15. Combat Air

  9. Advanced Tactical Crew System (ATACS) Issues and Options: Impacts on Aircrew Selection and Training.

    Science.gov (United States)

    1981-10-01

    differiing iiiflt- e’\\ ielt of their cee’tralizat inn (flthIoic inion vand w4here prolemtis). si i de’se-ri li inand ispec-i fi~at ionare Ii ot limajor... trainer aircralt nol haitw Ille ;16ollic req Ili rvlnefll of Ow loll iiii-ion aircrall. thie derkalilf. collco-Ill mIlich hil not bvvn Ilientioni-d i- that

  10. Cross-cultural attitudes of flight crew regarding CRM

    Science.gov (United States)

    Merritt, Ashleigh

    1993-01-01

    This study asks if the Cockpit Management Attitude Questionnaire (CMAQ) can detect differences across countries, and/or across occupations. And if so, can those differences be interpreted? Research has shown that the CMAQ is sensitive to attitude differences between and within organizations, thereby demonstrating its effectiveness with American populations. But the CMAQ was originally designed by American researchers and psychometrically refined for American pilots. The items in the questionnaire, though general in nature, still reflect the ubiquitous Western bias, because the items were written by researchers from and for the one culture. Recognizing this constraint, this study is nonetheless interested in attitudes toward crew behavior, and how those attitudes may vary across country and occupation.

  11. Experimental Evaluation of the Hydrodynamic Response of Crew Boat Hulls

    DEFF Research Database (Denmark)

    Pecher, Arthur; Kofoed, Jens Peter

    This report presents the results of an experimental study on 3 different hulls of crew boats intended for service to offshore wind turbines. Their hydrodynamic behaviour has been tested in various sea states representing general wave conditions that could be expected at offshore wind farms. Two...... main setups were used during the tests, corresponding to the hulls being connected to an offshore windmill and being free floating. The following aspects were the main subjects of investigation: • The Response Amplitude Operators of the hulls in two different configurations and with waves coming from 3...... the supervision of Jens Peter Kofoed in the deep wave basin in the Hydraulics and Coastal Engineering laboratory at Aalborg University during spring 2012....

  12. STS-65 Columbia, Orbiter Vehicle (OV) 102, crew insignia

    Science.gov (United States)

    1994-01-01

    STS-65 Columbia, Orbiter Vehicle (OV) 102, crew insignia (logo), the Official insignia of the NASA STS-65 International Microgravity Laboratory 2 (IML-2) mission. Designed by the crewmembers, the STS-65 insignia features the IML-2 mission and its Spacelab module which will fly aboard the Space Shuttle Columbia. IML-2 is reflected in the emblem by two gold stars shooting toward the heavens behind the IML lettering. The Space Shuttle Columbia is depicted orbiting the logo and reaching off into space, with Spacelab on an international quest for a better understanding of the effects of space flight on materials processing and life sciences. The STS-65 flight crewmembers are Commander Robert D. Cabana, Pilot James D. Halsell, Jr, Mission Specialist (MS) and Payload Commander (PLC) Richard J. Hieb, MS Carl E. Walz, MS Leroy Chiao, MS Donald A. Thomas, and Japanese Payload Specialist Chiaki Mukai.

  13. Farming-up coastal fish assemblages through a massive aquaculture escape event.

    Science.gov (United States)

    Toledo-Guedes, Kilian; Sanchez-Jerez, Pablo; Benjumea, María E; Brito, Alberto

    2014-07-01

    We investigated the changes on the mean trophic level of fish assemblages across different spatiotemporal scales, before and after a massive escape event occurred off La Palma (Canary Islands), which resulted in the release of 1.5 million fish (mostly Dicentrarchus labrax) into the wild. The presence of escaped fish altered significantly the mean trophic level of fish assemblages in shallow coastal waters. This alteration was exacerbated by the massive escape. A nearby marine protected area buffered the changes in mean trophic level but exhibited the same temporal patterns as highly fished areas. Moreover, escaped fish exploited natural resources according to their total length and possibly, time since escapement. New concerns arise as a "farming up" process is detected in shallow coastal fish assemblages where marine aquaculture is established.

  14. Flight Crew Responses to the Interval Management Alternative Clearances (IMAC) Experiment

    Science.gov (United States)

    Baxley, Brian T.; Wilson, Sara R.; Swieringa, Kurt A.; Roper, Roy D.

    2016-01-01

    Interval Management Alternative Clearances (IMAC) was a human-in-the-loop simulation experiment conducted to explore the efficacy and acceptability of three IM operations: CAPTURE, CROSS, and MAINTAIN. Two weeks of data collection were conducted, with each week using twelve subject pilots and four subject controllers flying ten high-density arrival scenarios into the Denver International Airport. Overall, both the IM operations and procedures were rated very favorably by the flight crew in terms of acceptability, workload, and pilot head down time. However, several critical issues were identified requiring resolution prior to real-world implementation, including the high frequency of IM speed commands, IM speed commands requiring changes to aircraft configuration, and ambiguous IM cockpit displays that did not trigger the intended pilot reaction. The results from this experiment will be used to prepare for a flight test in 2017, and to support the development of an advanced IM concept of operations by the FAA (Federal Aviation Agency) and aviation industry.

  15. Requirements for Designing Life Support System Architectures for Crewed Exploration Missions Beyond Low-Earth Orbit

    Science.gov (United States)

    Howard, David; Perry,Jay; Sargusingh, Miriam; Toomarian, Nikzad

    2016-01-01

    NASA's technology development roadmaps provide guidance to focus technological development on areas that enable crewed exploration missions beyond low-Earth orbit. Specifically, the technology area roadmap on human health, life support and habitation systems describes the need for life support system (LSS) technologies that can improve reliability and in-situ maintainability within a minimally-sized package while enabling a high degree of mission autonomy. To address the needs outlined by the guiding technology area roadmap, NASA's Advanced Exploration Systems (AES) Program has commissioned the Life Support Systems (LSS) Project to lead technology development in the areas of water recovery and management, atmosphere revitalization, and environmental monitoring. A notional exploration LSS architecture derived from the International Space has been developed and serves as the developmental basis for these efforts. Functional requirements and key performance parameters that guide the exploration LSS technology development efforts are presented and discussed. Areas where LSS flight operations aboard the ISS afford lessons learned that are relevant to exploration missions are highlighted.

  16. DR-induced escape of O and C from early Mars

    Science.gov (United States)

    Zhao, Jinjin; Tian, Feng; Ni, Yufang; Huang, Xiaomeng

    2017-03-01

    Energetic particles produced in Dissociative recombination (DR) reactions could escape planets with low gravity, such as Mars, if they could overcome collisions with the surrounding background gases. In this work, a 3-D Monte Carlo model is developed to study these photochemical escape processes on early Mars. Although the DR reaction rates of O2+, CO2+, and CO+ increase monotonically with solar soft X-ray and extreme ultraviolet (XUV) flux, the peak of the calculated DR-induced escape rates of O is near 3 × XUV, and the DR-induced escape rates of C increase with XUV until 10 × XUV. The non-monotonic behavior can be explained by the increased column densities of background species in high XUV conditions, which can deflect energetic particles through collisions more efficiently. At 20 × XUV, CO+ DR is the main source of escaping O and C, and the escape of secondary particles could contribute to 30∼40% and 10% of the total escape of O and C respectively. The time-integrated DR-induced escape of O and C is equivalent to 1 m of H2O and 20 mbar of CO2 escaping early Mars since 4.5 billion years ago. The accumulated CO2 loss is much lower than what's needed to explain the carbon isotopic ratios on Mars and much lower than the total CO2 needed to warm up early Mars. If more vigorous escape mechanisms were absent on early Mars, substantial inventories of volatiles have not been detected yet.

  17. Photochemical escape of oxygen from the Martian atmosphere: new insights from MAVEN

    Science.gov (United States)

    Lillis, R. J.; Deighan, J.; Bougher, S. W.; Cravens, T.; Fox, J. L.; Lee, Y.; Rahmati, A.; McFadden, J. P.; Benna, M.; Mahaffy, P. R.; Elrod, M. K.; Andersson, L.; Fowler, C. M.; Curry, S.; Gröller, H.; Jakosky, B. M.

    2015-12-01

    One of the primary goals of the MAVEN mission is to characterize rates of atmospheric escape from Mars at the present epoch and relate those escape rates to solar drivers. One of the known escape processes is photochemical escape, where a) an exothermic chemical reaction in the atmosphere results in an upward-traveling neutral particle whose velocity exceeds planetary escape velocity and b) the particle is not prevented from escaping through any subsequent collisions. Because escaping hot atoms are not directly measured, models of production and transport (through the atmosphere) of such atoms must be used to constrain photochemical escape rates. These models require altitude profiles of neutral densities and electron and ion densities and temperatures, as well as compositional information, all of which are measured by MAVEN instruments at the relevant altitudes (150-300 km). For every altitude profile: Profiles of O2+ dissociative recombination (DR) rates will be calculated from electron temperature, electron density and O2+ density. Profiles of energy distributions of hot O atoms will be calculated from profiles of electron and ion temperatures. Profiles of all neutral densities will be input into models of hot O transport in order to calculate photochemical escape fluxes from DR of O2+. We will present photochemical escape fluxes as a function of several factors, in particular solar zenith angle and EUV flux. This, combined with further simulations with progressively higher EUV fluxes, will eventually enable a total integrated loss estimate over the course of Martian history and hence a determination of the impact of this loss process on the evolution of the Martian climate.

  18. Functional Modelling, Scenario Development, and Options Analysis to Support Optimized Crewing for Damage Control. Phase 1: Functional Modelling

    Science.gov (United States)

    2006-05-18

    3.1 3.2.2.1 Beevis, Vallerand, and Greenley (2001). Technologies for workload and crewing reduction: Phase I project report (Defence R&D Canada... Greenley (2001)), an American report to congress reviewing recent efforts in crewing reductions (United States General Accounting Office, 2003), and...Review of the Optimized Crewing Literature 3.2.2.1 Beevis, Vallerand, and Greenley (2001). Technologies for workload and crewing reduction: Phase I

  19. Advanced construction management for lunar base construction - Surface operations planner

    Science.gov (United States)

    Kehoe, Robert P.

    1992-01-01

    The study proposes a conceptual solution and lays the framework for developing a new, sophisticated and intelligent tool for a lunar base construction crew to use. This concept integrates expert systems for critical decision making, virtual reality for training, logistics and laydown optimization, automated productivity measurements, and an advanced scheduling tool to form a unique new planning tool. The concept features extensive use of computers and expert systems software to support the actual work, while allowing the crew to control the project from the lunar surface. Consideration is given to a logistics data base, laydown area management, flexible critical progress scheduler, video simulation of assembly tasks, and assembly information and tracking documentation.

  20. Advanced Solid State Lighting for AES Deep Space Hab Project

    Science.gov (United States)

    Holbert, Eirik

    2015-01-01

    The advanced Solid State Lighting (SSL) assemblies augmented 2nd generation modules under development for the Advanced Exploration Systems Deep Space Habitat in using color therapy to synchronize crew circadian rhythms. Current RGB LED technology does not produce sufficient brightness to adequately address general lighting in addition to color therapy. The intent is to address both through a mix of white and RGB LEDs designing for fully addressable alertness/relaxation levels as well as more dramatic circadian shifts.

  1. Complex Economies Have a Lateral Escape from the Poverty Trap

    Science.gov (United States)

    Pugliese, Emanuele; Chiarotti, Guido L.; Zaccaria, Andrea; Pietronero, Luciano

    2017-01-01

    We analyze the decisive role played by the complexity of economic systems at the onset of the industrialization process of countries over the past 50 years. Our analysis of the input growth dynamics, considering a further dimension through a recently introduced measure of economic complexity, reveals that more differentiated and more complex economies face a lower barrier (in terms of GDP per capita) when starting the transition towards industrialization. As a consequence, we can extend the classical concept of a one-dimensional poverty trap, by introducing a two-dimensional poverty trap: a country will start the industrialization process if it is rich enough (as in neo-classical economic theories), complex enough (using this new dimension and laterally escaping from the poverty trap), or a linear combination of the two. This naturally leads to the proposal of a Complex Index of Relative Development (CIRD) which shows, when analyzed as a function of the growth due to input, a shape of an upside down parabola similar to that expected from the standard economic theories when considering only the GDP per capita dimension. PMID:28072867

  2. Modified guidance laws to escape microbursts with turbulence

    Directory of Open Access Journals (Sweden)

    Atilla Dogan

    2002-01-01

    Full Text Available This paper introduces Modified Altitude- and Dive-Guidance laws for escaping a microburst with turbulence. The goal is to develop a procedure to estimate the highest altitude at which an aircraft can fly through a microburst without running into stall. First, a new metric is constructed that quantifies the aircraft upward force capability in a microburst encounter. In the absence of turbulence, the metric is shown to be a decreasing function of altitude. This suggests that descending to a low altitude may improve safety in the sense that the aircraft will have more upward force capability to maintain its altitude. In the presence of stochastic turbulence, the metric is treated as a random variable and its probability distribution function is analytically approximated as a function of altitude. This approximation allows us to determine the highest safe altitude at which the aircraft may descend, hence avoiding to descend too low. This highest safe altitude is used as the commanded altitude in Modified Altitude- and Dive-Guidance. Monte Carlo simulations show that these Modified Altitude- and Dive-Guidance strategies can decrease the probability of minimum altitude being lower than a given value without significantly increasing the probability of crash.

  3. Escape of the martian protoatmosphere and initial water inventory

    CERN Document Server

    Erkaev, N V; Elkins-Tanton, L; Stökl, A; Odert, P; Marcq, E; Dorfi, E A; Kislyakova, K G; Kulikov, Yu N; Leitzinger, M; Güdel, M

    2013-01-01

    Latest research in planet formation indicate that Mars formed within a few million years (Myr) and remained a planetary embryo that never grew to a more massive planet. It can also be expected from dynamical models, that most of Mars' building blocks consisted of material that formed in orbital locations just beyond the ice line which could have contained ~0.1-0.2 wt. % of H2O. By using these constraints, we estimate the nebula-captured and catastrophically outgassed volatile contents during the solidification of Mars' magma ocean and apply a hydrodynamic upper atmosphere model for the study of the soft X-ray and extreme ultraviolet (XUV) driven thermal escape of the martian protoatmosphere during the early active epoch of the young Sun. The amount of gas that has been captured from the protoplanetary disk into the planetary atmosphere is calculated by solving the hydrostatic structure equations in the protoplanetary nebula. Depending on nebular properties such as the dust grain depletion factor, planetesimal...

  4. Dynamical correlations in the escape strategy of Influenza A virus

    Science.gov (United States)

    Taggi, L.; Colaiori, F.; Loreto, V.; Tria, F.

    2013-03-01

    The evolutionary dynamics of human Influenza A virus presents a challenging theoretical problem. An extremely high mutation rate allows the virus to escape, at each epidemic season, the host immune protection elicited by previous infections. At the same time, at each given epidemic season a single quasi-species, that is a set of closely related strains, is observed. A non-trivial relation between the genetic (i.e., at the sequence level) and the antigenic (i.e., related to the host immune response) distances can shed light into this puzzle. In this paper we introduce a model in which, in accordance with experimental observations, a simple interaction rule based on spatial correlations among point mutations dynamically defines an immunity space in the space of sequences. We investigate the static and dynamic structure of this space and we discuss how it affects the dynamics of the virus-host interaction. Interestingly we observe a staggered time structure in the virus evolution as in the real Influenza evolutionary dynamics.

  5. Nosema Tolerant Honeybees (Apis mellifera) Escape Parasitic Manipulation of Apoptosis

    Science.gov (United States)

    Kurze, Christoph; Le Conte, Yves; Dussaubat, Claudia; Erler, Silvio; Kryger, Per; Lewkowski, Oleg; Müller, Thomas; Widder, Miriam; Moritz, Robin F. A.

    2015-01-01

    Apoptosis is not only pivotal for development, but also for pathogen defence in multicellular organisms. Although numerous intracellular pathogens are known to interfere with the host’s apoptotic machinery to overcome this defence, its importance for host-parasite coevolution has been neglected. We conducted three inoculation experiments to investigate in the apoptotic respond during infection with the intracellular gut pathogen Nosema ceranae, which is considered as potential global threat to the honeybee (Apis mellifera) and other bee pollinators, in sensitive and tolerant honeybees. To explore apoptotic processes in the gut epithelium, we visualised apoptotic cells using TUNEL assays and measured the relative expression levels of subset of candidate genes involved in the apoptotic machinery using qPCR. Our results suggest that N. ceranae reduces apoptosis in sensitive honeybees by enhancing inhibitor of apoptosis protein-(iap)-2 gene transcription. Interestingly, this seems not be the case in Nosema tolerant honeybees. We propose that these tolerant honeybees are able to escape the manipulation of apoptosis by N. ceranae, which may have evolved a mechanism to regulate an anti-apoptotic gene as key adaptation for improved host invasion. PMID:26445372

  6. Nosema Tolerant Honeybees (Apis mellifera Escape Parasitic Manipulation of Apoptosis.

    Directory of Open Access Journals (Sweden)

    Christoph Kurze

    Full Text Available Apoptosis is not only pivotal for development, but also for pathogen defence in multicellular organisms. Although numerous intracellular pathogens are known to interfere with the host's apoptotic machinery to overcome this defence, its importance for host-parasite coevolution has been neglected. We conducted three inoculation experiments to investigate in the apoptotic respond during infection with the intracellular gut pathogen Nosema ceranae, which is considered as potential global threat to the honeybee (Apis mellifera and other bee pollinators, in sensitive and tolerant honeybees. To explore apoptotic processes in the gut epithelium, we visualised apoptotic cells using TUNEL assays and measured the relative expression levels of subset of candidate genes involved in the apoptotic machinery using qPCR. Our results suggest that N. ceranae reduces apoptosis in sensitive honeybees by enhancing inhibitor of apoptosis protein-(iap-2 gene transcription. Interestingly, this seems not be the case in Nosema tolerant honeybees. We propose that these tolerant honeybees are able to escape the manipulation of apoptosis by N. ceranae, which may have evolved a mechanism to regulate an anti-apoptotic gene as key adaptation for improved host invasion.

  7. Breakdown of the escape dynamics in Josephson junctions

    Science.gov (United States)

    Massarotti, D.; Stornaiuolo, D.; Lucignano, P.; Galletti, L.; Born, D.; Rotoli, G.; Lombardi, F.; Longobardi, L.; Tagliacozzo, A.; Tafuri, F.

    2015-08-01

    We have identified anomalous behavior of the escape rate out of the zero-voltage state in Josephson junctions with a high critical current density Jc. For this study we have employed YBa2Cu3O7 -x grain boundary junctions, which span a wide range of Jc and have appropriate electrodynamical parameters. Such high Jc junctions, when hysteretic, do not switch from the superconducting to the normal state following the expected stochastic Josephson distribution, despite having standard Josephson properties such as a Fraunhofer magnetic field pattern. The switching current distributions (SCDs) are consistent with nonequilibrium dynamics taking place on a local rather than a global scale. This means that macroscopic quantum phenomena seem to be practically unattainable for high Jc junctions. We argue that SCDs are an accurate means to measure nonequilibrium effects. This transition from global to local dynamics is of relevance for all kinds of weak links, including the emergent family of nanohybrid Josephson junctions. Therefore caution should be applied in the use of such junctions in, for instance, the search for Majorana fermions.

  8. A decision support system for crew planning in passenger transportation using a flexible branch-and-price algorithm

    NARCIS (Netherlands)

    R. Freling (Richard); R.M. Lentink (Ramon); A.P.M. Wagelmans (Albert)

    2001-01-01

    textabstractThis paper discusses a decision support system for airline and railway crew planning. The system is a state-of-the-art branch-and-price solver that is used for crew scheduling and crew rostering. We briefly discuss the mathematical background of the solver, of which most part is covered

  9. 78 FR 25846 - Special Conditions: Airbus, Model A340-600 Series Airplanes; Lower Deck Crew Rest Compartments

    Science.gov (United States)

    2013-05-03

    ...; Lower Deck Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final... unusual design feature associated with the installation of lower deck crew rest (LDCR) compartments. The... certificate to install a lower deck crew rest (LDCR) compartment in Airbus Model A340-600 series...

  10. 78 FR 21037 - Special Conditions: Airbus Model A330-200 Airplanes; Bulk Cargo Lower Deck Crew Rest Compartments

    Science.gov (United States)

    2013-04-09

    ... Cargo Lower Deck Crew Rest Compartments AGENCY: Federal Aviation Administration (FAA), DOT. ACTION... unusual design feature associated with the installation of bulk cargo lower deck crew rest compartments... supplemental type certificate to install a bulk cargo lower deck crew rest compartment in the Airbus Model...

  11. 8 CFR 231.2 - Electronic manifest and I-94 requirement for passengers and crew onboard departing vessels and...

    Science.gov (United States)

    2010-01-01

    ... section 231 of the Act are set forth in 19 CFR 4.64 (passengers and crew members onboard vessels) and in 19 CFR 122.75a (passengers onboard aircraft) and 122.75b (crew members onboard aircraft). (b... for passengers and crew onboard departing vessels and aircraft. 231.2 Section 231.2 Aliens...

  12. 8 CFR 231.1 - Electronic manifest and I-94 requirement for passengers and crew onboard arriving vessels and...

    Science.gov (United States)

    2010-01-01

    ... section 231 of the Act are set forth in 19 CFR 4.7b (passengers and crew members onboard vessels) and in 19 CFR 122.49a (passengers onboard aircraft) and 122.49b (crew members onboard aircraft). (b... for passengers and crew onboard arriving vessels and aircraft. 231.1 Section 231.1 Aliens...

  13. Crew Factors in Flight Operations XII: A Survey of Sleep Quantity and Quality in On-Board Crew Rest Facilities

    Science.gov (United States)

    Rosekind, Mark R.; Gregory, Kevin B.; Co, Elizabeth L.; Miller, Donna L.; Dinges, David F.

    2000-01-01

    Many aircraft operated on long-haul commercial airline flights are equipped with on-board crew rest facilities, or bunks, to allow crewmembers to rest during the flight. The primary objectives of this study were to gather data on how the bunks were used, the quantity and quality of sleep obtained by flight crewmembers in the facilities, and the factors that affected their sleep. A retrospective survey comprising 54 questions of varied format addressed demographics, home sleep habits, and bunk sleep habits. Crewmembers from three airlines with long-haul fleets carrying augmented crews consisting of B747-100/200, B747-400, and MD-11 aircraft equipped with bunks returned a total of 1404 completed surveys (a 37% response rate). Crewmembers from the three carriers were comparable demographically, although one carrier had older, more experienced flight crewmembers. Each group, on average, rated themselves as "good" or "very good" sleepers at home, and all groups obtained about the same average amount of sleep each night. Most were able to sleep in the bunks, and about two thirds indicated that these rest opportunities benefited their subsequent flight deck alertness and performance. Comfort, environment, and physiology (e.g., being ready for sleep) were identified as factors that most promoted sleep. Factors cited as interfering with sleep included random noise, thoughts, heat, and the need to use the bathroom. These factors, in turn, suggest potential improvements to bunk facilities and their use. Ratings of the three aircraft types suggested differences among facilities. Bunks in the MD-11 were rated significantly better than either of the B747 types, and the B747-400 bunks received better ratings than did the older, B747-100/200 facilities.

  14. Review of One Illness Away: Why People Become Poor and How They Escape Poverty

    OpenAIRE

    Afia B. Yamoah

    2011-01-01

    Afia B. Yamoah reviews One Illness Away: Why People Become Poor and How They Escape Poverty, by Anirudh Krishna. Krishna argues that poverty policy needs to address reasons why people become poor and how they can escape poverty.

  15. Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization.

    Science.gov (United States)

    Chung, Sai Ho; Ma, Hoi Lam; Chan, Hing Kai

    2016-12-09

    This article concerns the assignment of buffer time between two connected flights and the number of reserve crews in crew pairing to mitigate flight disruption due to flight arrival delay. Insufficient crew members for a flight will lead to flight disruptions such as delays or cancellations. In reality, most of these disruption cases are due to arrival delays of the previous flights. To tackle this problem, many research studies have examined the assignment method based on the historical flight arrival delay data of the concerned flights. However, flight arrival delays can be triggered by numerous factors. Accordingly, this article proposes a new forecasting approach using a cascade neural network, which considers a massive amount of historical flight arrival and departure data. The approach also incorporates learning ability so that unknown relationships behind the data can be revealed. Based on the expected flight arrival delay, the buffer time can be determined and a new dynamic reserve crew strategy can then be used to determine the required number of reserve crews. Numerical experiments are carried out based on one year of flight data obtained from 112 airports around the world. The results demonstrate that by predicting the flight departure delay as the input for the prediction of the flight arrival delay, the prediction accuracy can be increased. Moreover, by using the new dynamic reserve crew strategy, the total crew cost can be reduced. This significantly benefits airlines in flight schedule stability and cost saving in the current big data era.

  16. Advanced lipoxidation end-products.

    Science.gov (United States)

    Pamplona, Reinald

    2011-06-30

    Chemical and nonenzymatic molecular modifications induced by reactive carbonyl species (RCS) generated by peroxidation of membrane phospholipids acyl chains play a dual role as signaling molecules and as mediators of the aging process. Cytotoxic effects of RCS are due to their capacity to react with cellular constituents, forming advanced lipoxidation end-products (ALEs). Reactive carbonyl compounds are stable and can diffuse within or even escape from the cell and attack targets far from the site of formation. The consequent loss of function and structural integrity of modified biomolecules can have a wide range of downstream functional consequences and may be the cause of subsequent cellular dysfunctions and tissue damage.

  17. Reporter assay for endo/lysosomal escape of toxin-based therapeutics.

    Science.gov (United States)

    Gilabert-Oriol, Roger; Thakur, Mayank; von Mallinckrodt, Benedicta; Bhargava, Cheenu; Wiesner, Burkhard; Eichhorst, Jenny; Melzig, Matthias F; Fuchs, Hendrik; Weng, Alexander

    2014-05-22

    Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters-horseradish peroxidase (HRP), Alexa Fluor 488 (Alexa) and ricin A-chain (RTA)-were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates-saporin-HRP, (Alexa)saporin and saporin-KQ-RTA-were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release) or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape) was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of (Alexa)saporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10-1000 nM.

  18. Failure of rats to escape from a potentially lethal microwave field

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, D.R.; Levinson, D.M.; Justesen, D.R.; Clarke, R.L.

    1980-01-01

    Ocularly pigmented rats, all mature females of the Long-Evans strain, were repeatedly presented an opportunity to escape from an intense 918-MHz field (whole-body dose rate . 60 mW/g) to a field of lower intensity (40, 30, 20, or 2 mW/g) by performing a simple locomotor response. Other rats could escape 800-microamperemeter faradic shock to the feet and tail by performing the same response in the same milieu, a multimode cavity. None of 20 irradiated rats learned to associate entry into a visually well-demarcated area of the cavity with immediate reduction of dose rate, in spite of field-induced elevations of body temperature to levels that exceeded 41 degrees C and would have been lethal but for a limit on durations of irradiation. In contrast, all of ten rats motivated by faradic shock rapidly learned to escape. The failure of escape learning by irradiated animals probably arose from deficiencies of motivation and, especially, sensory feedback. Whole-body hyperthermia induced by a multipath field may lack the painful or directional sensory properties that optimally promote the motive to escape. Moreover, a decline of body temperature after an escape-response-contingent reduction of field strength will be relatively slow because of the large thermal time constants of mammalian tissues. Without timely sensory feedback, which is an essential element of negative reinforcement, stimulus-response associability would be imparied, which could retard or preclude learning of an escape response.

  19. H Escape Rates Inferred from MAVEN/IUVS Observations of the Mars Hydrogen Corona

    Science.gov (United States)

    Chaffin, Michael S.; Chaufray, Jean-Yves; Deighan, Justin; Schneider, Nicholas M.; McClintock, William; Stewart, A. Ian F.; Thiemann, E. M.; Clarke, John T.; Holsclaw, Gregory; Jain, Sonal Kumar; Crismani, Matteo; Stiepen, Arnaud; Montmessin, Franck; Eparvier, Francis; Jakosky, Bruce

    2016-10-01

    H escape oxidizes and dessicates the Mars atmosphere and surface, providing a key control on the present-day chemistry and long-term evolution of the planet. Recently, large variations in the escape rate of H as a function of season have been reported by several studies, making continued observation of the variation a high priority. We present escape rates derived from Mars Atmosphere and Volatile EvolutioN (MAVEN) mission Imaging UltraViolet Spectrograph (IUVS) observations of the extended atmosphere of Mars at H Lyman alpha (121.6 nm), which must be interpreted with a coupled density/radiative transfer model owing to the optically thick nature of the emission and the small fraction of H present in the corona on escaping trajectories. We recover densities, temperatures, and escape rates under the assumption of spherical symmetry for multiple periods across MAVEN's mission so far, beginning in December 2014 (escape rates ~4e8/cm2/s). We describe the observed variation and compare it with previously observed seasonal variation in retrieved H escape rates, providing a necessary input for future photochemical modeling studies and estimates of water loss from Mars over its history.

  20. Reporter Assay for Endo/Lysosomal Escape of Toxin-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Roger Gilabert-Oriol

    2014-05-01

    Full Text Available Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters—horseradish peroxidase (HRP, Alexa Fluor 488 (Alexa and ricin A-chain (RTA—were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates—saporin-HRP, Alexasaporin and saporin-KQ-RTA—were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of Alexasaporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10–1000 nM.

  1. Do malaria parasites manipulate the escape behaviour of their avian hosts? An experimental study.

    Science.gov (United States)

    Garcia-Longoria, Luz; Møller, Anders P; Balbontín, Javier; de Lope, Florentino; Marzal, Alfonso

    2015-12-01

    Escape behaviour is the behaviour that birds and other animals display when already caught by a predator. An individual exhibiting higher intensity of such anti-predator behaviour could have greater probabilities of escape from predators. Parasites are known to affect different aspects of host behaviour to increase their own fitness. Vector-transmitted parasites such as malaria parasites should gain by manipulating their hosts to enhance the probability of transmission. Several studies have shown that malaria parasites can manipulate their vectors leading to increased transmission success. However, little is known about whether malaria parasites can manipulate escape behaviour of their avian hosts thereby increasing the spread of the parasite. Here we used an experimental approach to explore if Plasmodium relictum can manipulate the escape behaviour of one of its most common avian hosts, the house sparrow Passer domesticus. We experimentally tested whether malaria parasites manipulate the escape behaviour of their avian host. We showed a decrease in the intensity of biting and tonic immobility after removal of infection with anti-malaria medication compared to pre-experimental behaviour. These outcomes suggest that infected sparrows performed more intense escape behaviour, which would increase the likelihood of individuals escaping from predators, but also benefit the parasite by increasing its transmission opportunities.

  2. Heart rate and core temperature responses of elite pit crews during automobile races.

    Science.gov (United States)

    Ferguson, David P; Bowen, Robert S; Lightfoot, J Timothy

    2011-08-01

    There is limited information regarding the physiological and psychological demands of the racing environment, and the subsequent effect on the performance of pit crew athletes. The purpose of this study was to evaluate heart rates (HRs) and core body temperatures (CTs) of pit crew athletes in the race environment. The HR and CT of pit crew athletes (n = 7) and control subjects were measured during 6 National Association for Stock Car Automobile Racing Sprint Cup races using ingestible sensors (HQ Inc, Palmetto, FL, USA). The HR and CT were measured before each race, at 15-minute intervals during the race, and upon completion of each pit stop. Compared to the control subject at each race, the pit crew athletes had significantly (p = 0.014) lower core temperatures (CTs). The pit crew athletes displayed higher HRs on the asphalt tracks than on concrete tracks (p = 0.011), and HR responses of the crew members were significantly (p = 0.012) different between pit crew positions, with the tire changers and jackman exhibiting higher HRs than the tire carriers. Unexpectedly, the CTs of the pit crew athletes were not elevated in the race environment, despite high ambient temperatures and the extensive fire-protection equipment (e.g., helmet, suit, gloves) each pit crew athlete wore. The lack of CT change is possibly the result of the increased HR more efficiently shunting blood to the skin and dissipating heat as a consequence of the athletes' extensive training regimen and ensuing heat acclimation. Additionally, it is possible that psychological stress unique to several of the tracks provided an additive effect resulting in increased heart rates.

  3. Utilization of the International Space Station for Crew Autonomous Scheduling Test (CAST)

    Science.gov (United States)

    Healy, Matthew; Marquez, Jesica; Hillenius, Steven; Korth, David; Bakalyar, Laure Rush; Woodbury, Neil; Larsen, Crystal M.; Bates, Shelby; Kockler, Mikayla; Rhodes, Brooke; Moore, William E., III; Deliz, Ivonne; Kanefsky, Bob; Zheng, Jimin; Henninger, Ashley; Edhlund, Isabelle; Smith, Kate; Kockler, William; Silva-Martinez, Jackelynne

    2017-01-01

    The United States space policy is evolving toward missions beyond low Earth orbit. In an effort to meet that policy, NASA has recognized Autonomous Mission Operations (AMO) as a valuable capability. Identified within AMO capabilities is the potential for autonomous planning and replanning during human spaceflight operations. That is allowing crew members to collectively or individually participate in the development of their own schedules. Currently, dedicated mission operations planners collaborate with international partners to create daily plans for astronauts aboard the International Space Station (ISS), taking into account mission requirements, ground rules, and various vehicle and payload constraints. In future deep space operations the crew will require more independence from ground support due to communication transmission delays. Furthermore, crew members who are provided with the capability to schedule their own activities are able to leverage direct experience operating in the space environment, and possibly maximize their efficiency. CAST (Crew Autonomous Scheduling Test) is an ISS investigation designed to analyze three important hypotheses about crew autonomous scheduling. First, given appropriate inputs, the crew is able to create and execute a plan in a reasonable period of time without impacts to mission success. Second, the proximity of the planner, in this case the crew, to the planned operations increases their operational efficiency. Third, crew members are more satisfied when given a role in plan development. This paper presents the results from a single astronaut test subject who participated in five CAST sessions. The details on the operational philosophy of CAST are discussed, including the approach to crew training, selection criteria for test days, and data collection methods. CAST is a technology demonstration payload sponsored by the ISS Research Science and Technology Office, and performed by experts in Mission Operations Planning from

  4. Quantifying the impact of human immunodeficiency virus-1 escape from cytotoxic T-lymphocytes.

    Directory of Open Access Journals (Sweden)

    Ulrich D Kadolsky

    Full Text Available HIV-1 escape from the cytotoxic T-lymphocyte (CTL response leads to a weakening of viral control and is likely to be detrimental to the patient. To date, the impact of escape on viral load and CD4(+ T cell count has not been quantified, primarily because of sparse longitudinal data and the difficulty of separating cause and effect in cross-sectional studies. We use two independent methods to quantify the impact of HIV-1 escape from CTLs in chronic infection: mathematical modelling of escape and statistical analysis of a cross-sectional cohort. Mathematical modelling revealed a modest increase in log viral load of 0.051 copies ml(-1 per escape event. Analysis of the cross-sectional cohort revealed a significant positive association between viral load and the number of "escape events", after correcting for length of infection and rate of replication. We estimate that a single CTL escape event leads to a viral load increase of 0.11 log copies ml(-1 (95% confidence interval: 0.040-0.18, consistent with the predictions from the mathematical modelling. Overall, the number of escape events could only account for approximately 6% of the viral load variation in the cohort. Our findings indicate that although the loss of the CTL response for a single epitope results in a highly statistically significant increase in viral load, the biological impact is modest. We suggest that this small increase in viral load is explained by the small growth advantage of the variant relative to the wildtype virus. Escape from CTLs had a measurable, but unexpectedly low, impact on viral load in chronic infection.

  5. The impact of escaped farmed Atlantic salmon (Salmo salar L. on catch statistics in Scotland.

    Directory of Open Access Journals (Sweden)

    Darren M Green

    Full Text Available In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L. may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed and sea trout (Salmo trutta L.. This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible.

  6. Bol d'Or success for all-women crew from CERN

    CERN Multimedia

    2001-01-01

    The boat 'Mic Mac' and its CERN's all-woman crew (left to right), Christine Theurillat, Ursula Haenger , Paola Catapano, Petra Riedler, and skipper Cristina Morone. Spectacular highlight of the Lake Leman sailing calendar is the annual Bol d'Or race. Held this year on 16 and 17 June, the event attracted nearly 500 teams who competed under extreme weather conditions for the honours. Among the competitors was an all-woman crew from the CERN Yachting Club, sailing their Surprise boat, Mic Mac. The team was not only among the 397 boats to finish, but also the first all-woman crewed single hull boat to cross the line.

  7. Liaison-Supplemented Navigation of a Crewed Vehicle in a Lunar Halo Orbit

    Science.gov (United States)

    Parker, Jeffrey S.; Leonard, Jason M.; Anderson, Rodney L.; Born, George H.

    2013-01-01

    This paper offers an early examination of the challenges of navigating a crewed vehicle, with all of the associated unmodeled accelerations that arise from the crew's activities, in an orbit about the Earth-Moon L2 point. The combination of the unstable nature of libration orbits with the lack of acceleration knowledge makes the station keeping strategy challenging. It is found that a combination of ground tracking and satellite-to-satellite tracking produces the most favorable navigation accuracy. This paper examines the costs and benefits of applying LiAISON (Linked Autonomous Interplanetary Satellite Orbit Navigation) to a crewed mission in an unstable L2 orbit.

  8. Turning pain into cues for goal-directed behavior : Implementation intentions reduce escape-avoidance behavior on a painful task

    NARCIS (Netherlands)

    Karsdorp, P.A.; Geenen, R.; Kroese, F.M.; Vlaeyen, J.W.S.

    2016-01-01

    Pain automatically elicits escape-avoidance behavior to avert bodily harm. In patients with chronic pain, long-term escape-avoidance behavior may increase the risk of chronic disability. The aim of the presents study was to examine whether implementation intentions reduce escape-avoidance behavior d

  9. Optimal search and ambush for a hider who can escape the search region

    OpenAIRE

    Alpern, Steve; Fokkink, Robbert; Simanjuntak, Martin

    2016-01-01

    Search games for a mobile or immobile hider traditionally have the hider permanently confined to a compact ‘search region’ making eventual capture inevitable. Hence the payoff can be taken as time until capture. However in many real life search problems it is possible for the hider to escape an area in which he was known to be located (e.g. Bin Laden from Tora Bora) or for a prey animal to escape a predator’s hunting territory. We model and solve such continuous time problems with escape wher...

  10. Mean Exit Time and Escape Probability for a Tumor Growth System under Non-Gaussian Noise

    CERN Document Server

    Ren, Jian; Gao, Ting; Kan, Xingye; Duan, Jinqiao

    2011-01-01

    Effects of non-Gaussian $\\alpha-$stable L\\'evy noise on the Gompertz tumor growth model are quantified by considering the mean exit time and escape probability of the cancer cell density from inside a safe or benign domain. The mean exit time and escape probability problems are formulated in a differential-integral equation with a fractional Laplacian operator. Numerical simulations are conducted to evaluate how the mean exit time and escape probability vary or bifurcates when $\\alpha$ changes. Some bifurcation phenomena are observed and their impacts are discussed.

  11. Occupant Protection during Orion Crew Exploration Vehicle Landings

    Science.gov (United States)

    Gernhardt, Michael L.; Jones, J. A.; Granderson, B. K.; Somers, J. T.

    2009-01-01

    The constellation program is evaluating current vehicle design capabilities for nominal water landings and contingency land landings of the Orion Crew Exploration vehicle. The Orion Landing Strategy tiger team was formed to lead the technical effort for which associated activities include the current vehicle design, susceptibility to roll control and tip over, reviewing methods for assessing occupant injury during ascent / aborts /landings, developing an alternate seat/attenuation design solution which improves occupant protection and operability, and testing the seat/attenuation system designs to ensure valid results. The EVA physiology, systems and Performance (EPSP) project is leading the effort under the authority of the Tiger Team Steering committee to develop, verify, validate and accredit biodynamics models using a variety of crash and injury databases including NASCAR, Indy Car and military aircraft. The validated biodynamics models will be used by the Constellation program to evaluate a variety of vehicle, seat and restraint designs in the context of multiple nominal and off-nominal landing scenarios. The models will be used in conjunction with Acceptable Injury Risk definitions to provide new occupant protection requirements for the Constellation Program.

  12. Simulation Development and Analysis of Crew Vehicle Ascent Abort

    Science.gov (United States)

    Wong, Chi S.

    2016-01-01

    NASA's Commercial Crew Program is an integral step in its journey to Mars as it would expedite development of space technologies and open up partnership with U.S. commercial companies. NASA reviews and independent assessment of Commercial Crew Program is fundamental to its success, and being able to model a commercial crew vehicle in a simulation rather than conduct a live test would be a safer, faster, and less expensive way to assess and certify the capabilities of the vehicle. To this end, my project was to determine the feasibility of using a simulation tool named SOMBAT version 2.0 to model a multiple parachute system for Commercial Crew Program simulation. The main tasks assigned to me were to debug and test the main parachute system model, (capable of simulating one to four main parachute bodies), and to utilize a graphical program to animate the simulation results. To begin tackling the first task, I learned how to use SOMBAT by familiarizing myself with its mechanics and by understanding the methods used to tweak its various parameters and outputs. I then used this new knowledge to set up, run, and analyze many different situations within SOMBAT in order to explore the limitations of the parachute model. Some examples of parameters that I varied include the initial velocity and orientation of the falling capsule, the number of main parachutes, and the location where the parachutes were attached to the capsule. Each parameter changed would give a different output, and in some cases, would expose a bug or limitation in the model. A major bug that I discovered was the inability of the model to handle any number of parachutes other than three. I spent quite some time trying to debug the code logically, but was unable to figure it out until my mentor taught me that digital simulation limitations can occur when some approximations are mistakenly assumed for certain in a physical system. This led me to the realization that unlike in all of the programming classes

  13. Acoustic and Vibration Environment for Crew Launch Vehicle Mobile Launcher

    Science.gov (United States)

    Vu, Bruce T.

    2007-01-01

    A launch-induced acoustic environment represents a dynamic load on the exposed facilities and ground support equipment (GSE) in the form of random pressures fluctuating around the ambient atmospheric pressure. In response to these fluctuating pressures, structural vibrations are generated and transmitted throughout the structure and to the equipment items supported by the structure. Certain equipment items are also excited by the direct acoustic input as well as by the vibration transmitted through the supporting structure. This paper presents the predicted acoustic and vibration environments induced by the launch of the Crew Launch Vehicle (CLV) from Launch Complex (LC) 39. The predicted acoustic environment depicted in this paper was calculated by scaling the statistically processed measured data available from Saturn V launches to the anticipated environment of the CLV launch. The scaling was accomplished by using the 5-segment Solid Rocket Booster (SRB) engine parameters. Derivation of vibration environment for various Mobile Launcher (ML) structures throughout the base and tower was accomplished by scaling the Saturn V vibration environment.

  14. The Single Crew Module Concept a Streamlined Way to Explore

    Science.gov (United States)

    Chambliss, Joe

    2012-01-01

    Many concepts have been proposed for exploring space. In early 2010 presidential direction called for reconsidering the approach to address changes in exploration destinations, use of new technologies and development of new capabilities to support exploration of space. Considering the proposed new technology and capabilities that NASA was directed to pursue, the single crew module (SCM) concept for a more streamlined approach to the infrastructure and conduct of exploration missions was developed. The SCM concept combines many of the new promising technologies with a central concept of mission architectures that uses a single habitat module for all phases of an exploration mission. Integrating mission elements near Earth and fully fueling them prior to departure of the vicinity of Earth provides the capability of using the single habitat both in transit to an exploration destination and while exploring the destination. The concept employs the capability to return the habitat and interplanetary propulsion system to Earth vicinity so that those elements can be reused on subsequent exploration missions. This paper describes the SCM concept, and the advantages it provides to accomplish exploration objectives.

  15. rHEALTH X with Non-Invasive Capabilities for Science and Crew Health Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is an extraordinary need for a universal biomedical analyzer that has broadly flexible capabilities for cell studies, small animal experiments, and crew member...

  16. A Model for Bus Crew Scheduling Problem with Multiple Duty Types

    Directory of Open Access Journals (Sweden)

    Mingming Chen

    2012-01-01

    Full Text Available This paper presents an approach for solving the bus crew scheduling problem which considers early, day, and late duty modes with time shift and work intensity constraints. Furthermore, the constraint with the least crew number of a certain duty (e.g., day duty has also been considered. An optimization model is formulated as a 0-1 integer programming problem to improve the efficiency of crew scheduling at the minimum expense of total idle time of crew for a circle bus line. Correspondingly, a heuristic algorithm utilizing the tabu search algorithm has been proposed to solve the model. Finally, the proposed model and algorithm are successfully tested by a case study.

  17. 78 FR 73876 - Agency Information Collection Activities: Passenger and Crew Manifest

    Science.gov (United States)

    2013-12-09

    ... about passengers and crew onboard inbound and outbound international flights before their arrival in or... Total Annual Burden Hours: 307,245. Estimated Costs: $68,361,719. Commercial Airline Passengers...

  18. The Integrated Medical Model: A Decision Support Tool for In-flight Crew Health Care

    Science.gov (United States)

    Butler, Doug

    2009-01-01

    This viewgraph presentation reviews the development of an Integrated Medical Model (IMM) decision support tool for in-flight crew health care safety. Clinical methods, resources, and case scenarios are also addressed.

  19. Crew interface analysis: Selected articles on space human factors research, 1987 - 1991

    Science.gov (United States)

    Bagian, Tandi (Compiler)

    1993-01-01

    As part of the Flight Crew Support Division at NASA, the Crew Interface Analysis Section is dedicated to the study of human factors in the manned space program. It assumes a specialized role that focuses on answering operational questions pertaining to NASA's Space Shuttle and Space Station Freedom Programs. One of the section's key contributions is to provide knowledge and information about human capabilities and limitations that promote optimal spacecraft and habitat design and use to enhance crew safety and productivity. The section provides human factors engineering for the ongoing missions as well as proposed missions that aim to put human settlements on the Moon and Mars. Research providing solutions to operational issues is the primary objective of the Crew Interface Analysis Section. The studies represent such subdisciplines as ergonomics, space habitability, man-computer interaction, and remote operator interaction.

  20. Socio-economic Survey of Commercial Fishing Crew in the Northeast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Northeast Fisheries Science Center's Social Sciences Branch (SSB) completed a survey of crew, including hired captains, participating in commercial fisheries in...

  1. Nonflammable Crew Clothing Utilizing Phosphorus-Based Fire-Retardant Materials Project

    Data.gov (United States)

    National Aeronautics and Space Administration — For maintaining U.S. leadership in space exploration, there is an urgent need to develop nonflammable crew clothing with the requirements of comfort, ease of...

  2. Escaping the poverty trap: modeling the interplay between economic growth and the ecology of infectious disease

    CERN Document Server

    Goerg, Georg M; Hébert-Dufresne, Laurent; Althouse, Benjamin M

    2013-01-01

    The dynamics of economies and infectious disease are inexorably linked: economic well-being influences health (sanitation, nutrition, treatment capacity, etc.) and health influences economic well-being (labor productivity lost to sickness and disease). Often societies are locked into ``poverty traps'' of poor health and poor economy. Here, using a simplified coupled disease-economic model with endogenous capital growth we demonstrate the formation of poverty traps, as well as ways to escape them. We suggest two possible mechanisms of escape both motivated by empirical data: one, through an influx of capital (development aid), and another through changing the percentage of GDP spent on healthcare. We find that a large influx of capital is successful in escaping the poverty trap, but increasing health spending alone is not. Our results demonstrate that escape from a poverty trap may be possible, and carry important policy implications in the world-wide distribution of aid and within-country healthcare spending.

  3. Escape dynamics in collinear atomic-like three mass point systems

    CERN Document Server

    Pasca, Daniel; Stoica, Cristina

    2009-01-01

    The present paper studies the escape mechanism in collinear three point mass systems with small-range-repulsive/large-range-attractive pairwise-interaction. Specifically, we focus on systems with non-negative total energy. We show that on the zero energy level set, most of the orbits lead to binary escape configurations and the set of initial conditions leading to escape configurations where all three separations infinitely increase as $t \\to \\infty 1$ has zero Lebesgue measure. We also give numerical evidence of the existence of a periodic orbit for the case when the two outer masses are equal. For positive energies, we prove that the set of initial conditions leading to escape configurations where all three separations infinitely increase as $t \\to \\infty$ has positive Lebesgue measure. Keywords: linear three point

  4. Unsteady motion: escape jumps in planktonic copepods, their kinematics and energetics

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Andersen, Anders Peter; Langlois, Vincent J.;

    2010-01-01

    estimate the force and power output needed to accelerate and overcome drag. Both are very high compared with those of other organisms, as are the escape velocities in comparison to startle velocities of other aquatic animals. Thus, the maximum weight-specific force, which for muscle motors of other animals...... has been found to be near constant at 57 N (kg muscle)−1, is more than an order of magnitude higher for the escaping copepods. We argue that this is feasible because most copepods have different systems for steady propulsion (feeding appendages) and intensive escapes (swimming legs), with the muscular...... arrangement of the latter probably adapted for high force production during short-lasting bursts. The resulting escape velocities scale with body length to power 0.65, different from the size-scaling of both similar sized and larger animals moving at constant velocity, but similar to that found for startle...

  5. Pizza or Pancake? Formation Models of Gas Escape Biosignatures in Terrestrial and Martian Sediments

    Science.gov (United States)

    Bonaccorsi, R.; Fairen, A. G.; Baker, L.; McKay, C. P.; Willson, D.

    2016-05-01

    Fine-grained sedimentary hollowed structures were imaged in Gale Crater, but no biomarkers identified to support biology. Our observation-based (gas escape) terrestrial model could inform on possible martian paleoenvironments at time of formation.

  6. STS-93: Columbia, Flight Crew Training with M-113 for Chandra

    Science.gov (United States)

    1999-01-01

    Live footage shows the crewmembers, Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley, Catherine G. Coleman, and Michel Tognini, standing in front of an M-113 armored personnel carrier vehicle, and posing for photographs. Footage also includes the crew inside the vehicle getting quick instructions on how to operate the vehicle. They are also seen taking turns in driving the vehicle, and taking photographs and recording each other as one member of the crew drives the vehicle.

  7. Whither CRM? Future directions in Crew Resource Management training in the cockpit and elsewhere

    Science.gov (United States)

    Helmreich, Robert L.

    1993-01-01

    The past decade has shown worldwide adoption of human factors training in civil aviation, now known as Crew Resource Management (CRM). The shift in name from cockpit to crew reflects a growing trend to extend the training to other components of the aviation system including flight attendants, dispatchers, maintenance personnel, and Air Traffic Controllers. The paper reports findings and new directions in research into human factors.

  8. Probability of illness definition for the Skylab flight crew health stabilization program

    Science.gov (United States)

    1974-01-01

    Management and analysis of crew and environmental microbiological data from SMEAT and Skylab are discussed. Samples were collected from ten different body sites on each SMEAT and Skylab crew-member on approximately 50 occasions and since several different organisms could be isolated from each sample, several thousand lab reports were generated. These lab reports were coded and entered in a computer file and from the file various tabular summaries were constructed.

  9. STS-47 Astronaut Crew at Pad B for TCDT, Emergency Egress Training, and Photo Opportunity

    Science.gov (United States)

    1992-01-01

    The crew of STS-47, Commander Robert L. Gibson, Pilot Curtis L. Brown, Payload Commander Mark C. Lee, Mission Specialists N. Jan Davis, Jay Apt, and Mae C. Jemison, and Payload Specialist Mamoru Mohri are seen during emergency egress training. Then Commander Gibson introduces the members of the crew and they each give a brief statement about the mission and answer questions from the press.

  10. Effectiveness improvement of psycho-physiological support of professional activity of navy ship crews

    OpenAIRE

    K.A. Bervitsky; I.A. Shevtchuk; A.N. Onishchenko

    2010-01-01

    The results of study of body functional status of members of Navy ship crews during sea campaigns and in the process of military professional adaptation have been analyzed. Psycho-physiological specificity of professional activity and regularity in changes of psycho-physiological parameters of military seamen have been estimated. Organization-staff and assessment-corrective measures of effectiveness improvement of psycho-physiological support of Navy ship crews' professional activity hav...

  11. Space Weather Monitoring for ISS Space Environments Engineering and Crew Auroral Observations

    Science.gov (United States)

    Minow, Joseph; Pettit, Donald R.; Hartman, William A.

    2012-01-01

    Today s presentation describes how real time space weather data is used by the International Space Station (ISS) space environments team to obtain data on auroral charging of the ISS vehicle and support ISS crew efforts to obtain auroral images from orbit. Topics covered include: Floating Potential Measurement Unit (FPMU), . Auroral charging of ISS, . Real ]time space weather monitoring resources, . Examples of ISS auroral charging captured from space weather events, . ISS crew observations of aurora.

  12. Occupational Health Screenings of Aeromedical Evacuation and Critical Care Air Transport Team Crew Members

    Science.gov (United States)

    2015-08-01

    concerning mental health problems. 3.2.2 Physical Exercise Behaviors. Participants were asked the following: how often do you engage in physical... depression ) as a reason for an increase in mental health supp01i utilization. CCATT crew members did not rep01i any other reasons for an increase...health care. However, AE crew members also endorsed emotional distress, such as depression , leading to their increase in seeking mental health care

  13. Influence of throat configuration and fish density on escapement of channel catfish from hoop nets

    Science.gov (United States)

    Porath, Mark T.; Pape, Larry D.; Richters, Lindsey K.

    2011-01-01

    In recent years, several state agencies have adopted the use of baited, tandemset hoop nets to assess lentic channel catfish Ictalurus punctatus populations. Some level of escapement from the net is expected because an opening exists in each throat of the net, although factors influencing rates of escapement from hoop nets have not been quantified. We conducted experiments to quantify rates of escapement and to determine the influence of throat configuration and fish density within the net on escapement rates. An initial experiment to determine the rate of escapement from each net compartment utilized individually tagged channel catfish placed within the entrance (between the two throats) and cod (within the second throat) compartments of a single hoop net for overnight sets. From this experiment, the mean rate (±SE) of channel catfish escaping was 4.2% (±1.5) from the cod (cod throat was additionally restricted from the traditionally manufactured product), and 74% (±4.2) from the entrance compartments. In a subsequent experiment, channel catfish were placed only in the cod compartment with different throat configurations (restricted or unrestricted) and at two densities (low [6 fish per net] and high [60 fish per net]) for overnight sets to determine the influence of fish density and throat configuration on escapement rates. Escapement rates between throat configurations were doubled at low fish density (13.3 ± 5.4% restricted versus 26.7 ± 5.6% unrestricted) and tripled at high fish density (14.3 ± 4.9% restricted versus 51.9 ± 5.0% unrestricted). These results suggest that retention efficiency is high from cod compartments with restricted throat entrances. However, managers and researchers need to be aware that modification to the cod throats (restrictions) is needed for hoop nets ordered from manufacturers. Managers need to be consistent in their use and reporting of cod end throat configurations when using this gear.

  14. Solution of the boundary value problem for optimal escape in continuous stochastic systems and maps.

    OpenAIRE

    S; Beri; Mannella, R.; Luchinsky, Dmitry G.; Silchenko, A. N.; McClintock, Peter V. E.

    2005-01-01

    Topologies of invariant manifolds and optimal trajectories are investigated in stochastic continuous systems and maps. A topological method is introduced that simplifies the solution of boundary value problems: The activation energy is calculated as a function of a set of parameters characterizing the initial conditions of the escape path. The method is applied explicitly to compute the optimal escape path and the activation energy for a variety of dynamical systems and maps.

  15. Choices between positive and negative reinforcement during treatment for escape-maintained behavior.

    Science.gov (United States)

    DeLeon, I G; Neidert, P L; Anders, B M; Rodriguez-Catter, V

    2001-01-01

    Positive reinforcement was more effective than negative reinforcement in promoting compliance and reducing escape-maintained problem behavior for a child with autism. Escape extinction was then added while the child was given a choice between positive or negative reinforcement for compliance and the reinforcement schedule was thinned. When the reinforcement requirement reached 10 consecutive tasks, the treatment effects became inconsistent and reinforcer selection shifted from a strong preference for positive reinforcement to an unstable selection pattern.

  16. THE EFFECTS OF FIXED-TIME ESCAPE ON INAPPROPRIATE AND APPROPRIATE CLASSROOM BEHAVIOR

    OpenAIRE

    Waller, Rachael D; Higbee, Thomas S.

    2010-01-01

    Few studies have explored the effects of fixed-time (FT) reinforcement on escape-maintained behavior of students in a classroom setting. We measured the effects of an FT schedule on the disruptive and appropriate academic behaviors of 2 junior high students in a public school setting. Results demonstrated that FT escape from tasks resulted in a substantial decrease in disruptive behavior and an increase in time engaged in tasks for both participants.

  17. Choices between positive and negative reinforcement during treatment for escape-maintained behavior.

    OpenAIRE

    DeLeon, I G; Neidert, P L; Anders, B M; Rodriguez-Catter, V

    2001-01-01

    Positive reinforcement was more effective than negative reinforcement in promoting compliance and reducing escape-maintained problem behavior for a child with autism. Escape extinction was then added while the child was given a choice between positive or negative reinforcement for compliance and the reinforcement schedule was thinned. When the reinforcement requirement reached 10 consecutive tasks, the treatment effects became inconsistent and reinforcer selection shifted from a strong prefer...

  18. The relationship between migration and development in the ESCAP region.

    Science.gov (United States)

    Skeldon, R

    1991-01-01

    The relationship between migration and development in the ESCAP region including southeast and south Asian countries and the Pacific island of Fiji, Papua New Guinea, Vanuatu, Kiribati, Samoa, and the Solomon Islands is discussed in terms of mobility transition and origin and destination factors. The changing patterns of mobility in Asia are further delineated in the discussion of internal movements and international movement. Emigration in the smaller countries of the Pacific are treated separately. Future predictions are that the Asia Pacific region will experience continued fertility decline and stabilization of low rates over the next 20 years. The declines will result in slow labor force growth, and increased demand for labor in traditional core and neocore countries as defined and presented in table form by Friedman will be heightened. International movements are likely to increase in large urban areas within destination countries. Tokyo and Singapore are the principal cities in Asia. Tokyo by restrictive government policy has limited immigration, but future labor shortages of unskilled labor from southeast Asia and China are expected. Singapore is already dependent on foreign labor by 10%. Current labor shortages have led to the creation of a growth triangle between Singapore, Indonesia, and Malaysia. Other cities expected to emerge as primary cities in international regional complexes with spillover into the hinterlands include the Hong Kong, Guangzhou, and Macau triangle in the Pearl River delta, Taipei and Seoul, and possibly Kuala Lumpur. Internal migration is expected to increase in the capital cities of Bangkok, Manila,j and centers such as Shanghai, Beijing, and other large cities of southeast Asia. These cities will be linked through the flows of skilled international migrants, which began in the 1960s and is expected to become a future major flow. Recreational and resource niches will be left in much of the Pacific, the Himalayan Kingdoms, and

  19. Quantifying the Escape Mortality of Trawl Caught Antarctic Krill (Euphausia superba)

    Science.gov (United States)

    Krafft, Bjørn A.; Krag, Ludvig A.; Engås, Arill; Nordrum, Sigve; Bruheim, Inge; Herrmann, Bent

    2016-01-01

    Antarctic krill (Euphausia superba) is an abundant fishery resource, the harvest levels of which are expected to increase. However, many of the length classes of krill can escape through commonly used commercial trawl mesh sizes. A vital component of the overall management of a fishery is to estimate the total fishing mortality and quantify the mortality rate of individuals that escape from fishing gear. The methods for determining fishing mortality in krill are still poorly developed. We used a covered codend sampling technique followed by onboard observations made in holding tanks to monitor mortality rates of escaped krill. Haul duration, hydrological conditions, maximum fishing depth and catch composition all had no significant effect on mortality of krill escaping 16 mm mesh size nets, nor was any further mortality associated with the holding tank conditions. A non- parametric Kaplan-Meier analysis was used to model the relationship between mortality rates of escapees and time. There was a weak tendency, though not significant, for smaller individuals to suffer higher mortality than larger individuals. The mortality of krill escaping the trawl nets in our study was 4.4 ± 4.4%, suggesting that krill are fairly tolerant of the capture-and-escape process in trawls. PMID:27622510

  20. Escape of Mars' CO2 atmosphere by suprathermal atoms during the past 4 Gyrs

    Science.gov (United States)

    Amerstorfer, Ute; Gröller, Hannes; Lichtenegger, Herbert; Lammer, Helmut; Tian, Feng

    2016-04-01

    The escape of atmospheric particles plays a crucial role in the evolution of the atmosphere of Mars. Especially, the escape of oxygen and carbon is thought to have influenced its amount of CO2. With a Monte-Carlo model we investigate the escape of hot oxygen and carbon from the martian atmosphere for three points in time in its history corresponding to 3, 10, and 20 times the present EUV level. We study and discuss different possible sources of hot oxygen and carbon atoms in the thermosphere and their changing importance with the EUV flux. We find that the escape due to photodissociation increases with increasing EUV level, as is a commonly assumed opinion. However, for the escape via other reactions, e.g. dissociative recombination, this is only true until the EUV level reaches 10 times the present EUV flux, but then the rates start to decrease. Our results thus suggest that some escape mechanisms related to the loss of CO2 are less important than previously thought for atmospheres exposed to higher EUV radiation. This work receives funding from the Austrian Science Fund (FWF): P 24247-N16.

  1. Hot oxygen escape from Mars: Simple scaling with solar EUV irradiance

    Science.gov (United States)

    Cravens, T. E.; Rahmati, A.; Fox, Jane L.; Lillis, R.; Bougher, S.; Luhmann, J.; Sakai, S.; Deighan, J.; Lee, Yuni; Combi, M.; Jakosky, B.

    2017-01-01

    The evolution of the atmosphere of Mars and the loss of volatiles over the lifetime of the solar system is a key topic in planetary science. An important loss process for atomic species, such as oxygen, is ionospheric photochemical escape. Dissociative recombination of O2+ ions (the major ion species) produces fast oxygen atoms, some of which can escape from the planet. Many theoretical hot O models have been constructed over the years, although a number of uncertainties are present in these models, particularly concerning the elastic cross sections of O atoms with CO2. Recently, the Mars Atmosphere and Volatile Evolution mission has been rapidly improving our understanding of the upper atmosphere and ionosphere of Mars and its interaction with the external environment (e.g., solar wind), allowing a new assessment of this important loss process. The purpose of the current paper is to take a simple analytical approach to the oxygen escape problem in order to (1) study the role that variations in solar radiation or solar wind fluxes could have on escape in a transparent fashion and (2) isolate the effects of uncertainties in oxygen cross sections on the derived oxygen escape rates. In agreement with several more elaborate numerical models, we find that the escape flux is directly proportional to the incident solar extreme ultraviolet irradiance and is inversely proportional to the backscatter elastic cross section. The amount of O lost due to ion transport in the topside ionosphere is found to be about 5-10% of the total.

  2. Lobelia siphilitica plants that escape herbivory in time also have reduced latex production.

    Directory of Open Access Journals (Sweden)

    Amy L Parachnowitsch

    Full Text Available Flowering phenology is an important determinant of a plant's reproductive success. Both assortative mating and niche construction can result in the evolution of correlations between phenology and other reproductive, functional, and life history traits. Correlations between phenology and herbivore defence traits are particularly likely because the timing of flowering can allow a plant to escape herbivory. To test whether herbivore escape and defence are correlated, we estimated phenotypic and genetic correlations between flowering phenology and latex production in greenhouse-grown Lobelia siphilitica L. (Lobeliaceae. Lobelia siphilitica plants that flower later escape herbivory by a specialist pre-dispersal seed predator, and thus should invest fewer resources in defence. Consistent with this prediction, we found that later flowering was phenotypically and genetically correlated with reduced latex production. To test whether herbivore escape and latex production were costly, we also measured four fitness correlates. Flowering phenology was negatively genetically correlated with three out of four fitness estimates, suggesting that herbivore escape can be costly. In contrast, we did not find evidence for costs of latex production. Generally, our results suggest that herbivore escape and defence traits will not evolve independently in L. siphilitica.

  3. CD4 binding site broadly neutralizing antibody selection of HIV-1 escape mutants.

    Science.gov (United States)

    Dreja, Hanna; Pade, Corinna; Chen, Lei; McKnight, Áine

    2015-07-01

    All human immunodeficiency virus type-1 (HIV-1) viruses use CD4 to enter cells. Consequently, the viral envelope CD4-binding site (CD4bs) is relatively conserved, making it a logical neutralizing antibody target. It is important to understand how CD4-binding site variation allows for escape from neutralizing antibodies. Alanine scanning mutagenesis identifies residues in antigenic sites, whereas escape mutant selection identifies viable mutants. We selected HIV-1 to escape CD4bs neutralizing mAbs b12, A12 and HJ16. Viruses that escape from A12 and b12 remained susceptible to HJ16, VRC01 and J3, whilst six different viruses that escape HJ16 remained sensitive to A12, b12 and J3. In contrast, their sensitivity to VRC01 was variable. Triple HJ16/A12/b12-resistant virus proved that HIV-1 could escape multiple broadly neutralizing monoclonal antibodies, but still retain sensitivity to VRC01 and the llama-derived J3 nanobody. This antigenic variability may reflect that occurring in circulating viruses, so studies like this can predict immunologically relevant antigenic forms of the CD4bs for inclusion in HIV-1 vaccines.

  4. Orbital and escape dynamics in barred galaxies - I. The 2D system

    CERN Document Server

    Jung, Christof

    2016-01-01

    In this paper we use the two-dimensional (2D) version of a new analytical gravitational model in order to explore the orbital as well as the escape dynamics of the stars in a barred galaxy composed of a spherically symmetric central nucleus, a bar, a flat disk and a dark matter halo component. A thorough numerical investigation is conducted for distinguishing between bounded and escaping motion. Furthermore bounded orbits are further classified into non-escaping regular and trapped chaotic using the Smaller ALingment Index (SALI) method. Our aim is to determine the basins of escape through the two symmetrical escape channels around the Lagrange points $L_2$ and $L_3$ and also to relate them with the corresponding distribution of the escape rates of the orbits. We integrate initial conditions of orbits in several types of planes so as to obtain a more complete view of the overall orbital properties of the dynamical system. We also present evidence that the unstable manifolds which guide the orbits in and out t...

  5. Escape-Route Planning of Underground Coal Mine Based on Improved Ant Algorithm

    Directory of Open Access Journals (Sweden)

    Guangwei Yan

    2013-01-01

    Full Text Available When a mine disaster occurs, to lessen disaster losses and improve survival chances of the trapped miners, good escape routes need to be found and used. Based on the improved ant algorithm, we proposed a new escape-route planning method of underground mines. At first, six factors which influence escape difficulty are evaluated and a weight calculation model is built to form a weighted graph of the underground tunnels. Then an improved ant algorithm is designed and used to find good escape routes. We proposed a tunnel network zoning method to improve the searching efficiency of the ant algorithm. We use max-min ant system method to optimize the meeting strategy of ants and improve the performance of the ant algorithm. In addition, when a small part of the mine tunnel network changes, the system may fix the optimal routes and avoid starting a new processing procedure. Experiments show that the proposed method can find good escape routes efficiently and can be used in the escape-route planning of large and medium underground coal mines.

  6. Fundamental Experiment to Determine Escape Countermeasures for Frogs Falling into Agricultural Canals

    Science.gov (United States)

    Watabe, Keiji; Mori, Atsushi; Koizumi, Noriyuki; Takemura, Takeshi

    Frogs often drown in agricultural canals with deep concrete walls, which are installed commonly in paddy fields after land improvement projects in Japan, because they cannot escape after falling into the canal. Therefore, countermeasures that enable frogs to escape from canals are required in some rural areas. An experimental canal with partially sloped walls was used as an escape countermeasure to investigate the preferable angle of slope for the walls, water depth and flow velocity that enables Tokyo Daruma Pond Frogs (Rana porosa porosa), which have no adhesive discs, to easily escape. Walls with slopes of 30-45 degrees allowed 50-60% of frogs to escape from the experimental canals, frogs especially easily climbed the 30 degree sloped walls. When the water depth was 5 cm or flow velocity was greater than 20 cm/s, approximately 80% of the frogs moved downstream and reached the sloped walls because the frogs' toes did not reach the bottom of the canal. However, if the depth was 2 cm and the flow velocity was 5 cm/s, only 4% of the frogs climbed the sloped walls because they could move freely. The frogs appeared to not be good at long-distance swimming and could not remain a long-time under running water. Therefore, walls sloped less than 30 degrees and control of both water depth and flow velocity appears important for enabling frogs to easily escape from canals.

  7. Effects of Serotonergic and Opioidergic Drugs on Escape Behaviors and Social Status of Male Crickets

    Science.gov (United States)

    Dyakonova, V. E.; Schürmann, F.-W.; Sakharov, D. A.

    We examined the effects of selective serotonin depletion and opioid ligands on social rank and related escape behavior of the cricket Gryllus bimaculatus. Establishment of social rank in a pair of males affected their escape reactions. Losers showed a lower and dominants a higher percentage of jumps in response to tactile cercal stimulation than before a fight. The serotonin-depleting drug α-methyltryptophan (AMTP) caused an activation of the escape reactivity in socially naive crickets. AMTP-treated animals also showed a lower ability to become dominants. With an initial 51.6+/-3.6% of wins in the AMTP group, the percentage decreased to 26+/-1.6% on day 5 after injection. The opiate receptor antagonist naloxone affected fight and escape similarly as AMTP. In contrast to naloxone, the opioid agonist [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin decreased escape responsiveness to cercal stimulation in naive and subordinate crickets. We suggest that serotonergic and opioid systems are involved in the dominance induced depression of escape behavior.

  8. Chaotic escape from an open vase-shaped cavity. I. Numerical and experimental results

    Science.gov (United States)

    Novick, Jaison; Keeler, Matthew L.; Giefer, Joshua; Delos, John B.

    2012-01-01

    We present part I in a two-part study of an open chaotic cavity shaped as a vase. The vase possesses an unstable periodic orbit in its neck. Trajectories passing through this orbit escape without return. For our analysis, we consider a family of trajectories launched from a point on the vase boundary. We imagine a vertical array of detectors past the unstable periodic orbit and, for each escaping trajectory, record the propagation time and the vertical detector position. We find that the escape time exhibits a complicated recursive structure. This recursive structure is explored in part I of our study. We present an approximation to the Helmholtz equation for waves escaping the vase. By choosing a set of detector points, we interpolate trajectories connecting the source to the different detector points. We use these interpolated classical trajectories to construct the solution to the wave equation at a detector point. Finally, we construct a plot of the detector position versus the escape time and compare this graph to the results of an experiment using classical ultrasound waves. We find that generally the classical trajectories organize the escaping ultrasound waves.

  9. Chaotic escape from an open vase-shaped cavity. II. Topological theory.

    Science.gov (United States)

    Novick, Jaison; Delos, John B

    2012-01-01

    We present part II of a study of chaotic escape from an open two-dimensional vase-shaped cavity. A surface of section reveals that the chaotic dynamics is controlled by a homoclinic tangle, the union of stable and unstable manifolds attached to a hyperbolic fixed point. Furthermore, the surface of section rectifies escape-time graphs into sequences of escape segments; each sequence is called an epistrophe. Some of the escape segments (and therefore some of the epistrophes) are forced by the topology of the dynamics of the homoclinic tangle. These topologically forced structures can be predicted using the method called homotopic lobe dynamics (HLD). HLD takes a finite length of the unstable manifold and a judiciously altered topology and returns a set of symbolic dynamical equations that encode the folding and stretching of the unstable manifold. We present three applications of this method to three different lengths of the unstable manifold. Using each set of dynamical equations, we compute minimal sets of escape segments associated with the unstable manifold, and minimal sets associated with a burst of trajectories emanating from a point on the vase's boundary. The topological theory predicts most of the early escape segments that are found in numerical computations.

  10. Location Tracking of Moving Crew Members for Effective Damage Control in an Emergency

    Directory of Open Access Journals (Sweden)

    Hee Jin Kang

    2011-01-01

    Full Text Available In an emergency, the commanding officer may have limited information, and crew members may behave differently compared to how they behaved during training. In an emergency situation, if the commanding officer is aware of each crew member's location and role in that situation, he can disseminate orders expeditiously and precisely. To realise a faster and more precise dissemination of orders through better awareness of each crew member's location and role, real-time crew member tracking is needed. The technical feasibility of a real time crew-tracking system based on a wireless sensor network has been studied, with the intent to improve effective commanding in an emergency. Herein, location tracking was achieved using instrumentation consisting of ZigBee tags, routers, and gateways, which were used to record the location and role data of moving crew members on a full-scale ship.Defence Science Journal, 2011, 61(1, pp.57-61, DOI:http://dx.doi.org/10.14429/dsj.61.503

  11. STS-69 Crew DEPARTs from O&C Building to Launch pad

    Science.gov (United States)

    1995-01-01

    Looking excited about their upcoming spaceflight, the Dog Crew II departs the Operations and Checkout Building. Leading the way is . While they are wearing the traditional crew emblem designed for each Shuttle mission, the STS-69 astronauts are also sporting a special patch denoting them as the Dog Crew I, continuing a tradition of comaraderie that began on an earlier flight, STS-53, on which both Walker and Voss were crew members. Each of the STS- 69 crew members took on a dog-theme name, and the patch, showing a bulldog peering from a doghouse shaped like the Space Shuttle, was designed to capture their sense of esprit de corps. Awaiting the crew at Launch Pad 39A is the Space Shuttle Endeavour, undergoing final preparations for liftoff on the fifth Shuttle flight of 1995. Launch is scheduled during a two and a half hour window opening at 11:09 a.m. EDT. This will be the second try to get STS-69 off the ground; a first attempt on Aug. 31 was scrubbed due to a faulty fuel cell.

  12. Access to enterntainment and information programming for the crew as part of the communication system of future Mars mission or Lunar Base

    Science.gov (United States)

    Hargitai, H.

    other problem. The opportunity of escaping from interpersonal problems can sometimes help, but have to handle with care since it can also keep the crew members from disuss and solve their problems in personal interaction. REFERENCES [1] Budden N. A., ed. (1999) Mars Field Geology, Biology, and Paleontology Workshop LPI No. 968 [2] Kanas, N. Psychological issues during long duration space missions. In 12th MIS Symposium, June 8 13, 1997, Washington,- 1997. [3] R. KASS and J. KASS: Psycho -social Training for man in space. Acta Astronautica Vol. 45, No. 2, pp. 115-118, 1999.

  13. Towards Curative Cancer Immunotherapy: Overcoming Posttherapy Tumor Escape

    Directory of Open Access Journals (Sweden)

    Gang Zhou

    2012-01-01

    Full Text Available The past decade has witnessed the evolvement of cancer immunotherapy as an increasingly effective therapeutic modality, evidenced by the approval of two immune-based products by the FDA, that is, the cancer vaccine Provenge (sipuleucel-T for prostate cancer and the antagonist antibody against cytotoxic T-lymphocyte antigen-4 (CTLA-4 ipilimumab for advanced melanoma. In addition, the clinical evaluations of a variety of promising immunotherapy drugs are well under way. Benefiting from more efficacious immunotherapeutic agents and treatment strategies, a number of recent clinical studies have achieved unprecedented therapeutic outcomes in some patients with certain types of cancers. Despite these advances, however, the efficacy of most cancer immunotherapies currently under clinical development has been modest. A recurring scenario is that therapeutic maneuvers initially led to measurable antitumor immune responses in cancer patients but ultimately failed to improve patient outcomes. It is increasingly recognized that tumor cells can antagonize therapy-induced immune attacks through a variety of counterregulation mechanisms, which represent a fundamental barrier to the success of cancer immunotherapy. Herein we summarize the findings from some recent preclinical and clinical studies, focusing on how tumor cells advance their survival and expansion by hijacking therapy-induced immune effector mechanisms that would otherwise mediate their destruction.

  14. Analysis and Design of Crew Sleep Station for ISS

    Science.gov (United States)

    Keener, John F.; Paul, Thomas; Eckhardt, Bradley; Smith, Fredrick

    2002-01-01

    This paper details the analysis and design of the Temporary Sleep Station (TeSS) environmental control system for International Space Station (ISS). The TeSS will provide crewmembers with a private and personal space, to accommodate sleeping, donning and doffing of clothing, personal communication and performance of recreational activities. The need for privacy to accommodate these activities requires adequate ventilation inside the TeSS. This study considers whether temperature, carbon dioxide, and humidity within the TeSS remain within crew comfort and safety levels for various expected operating scenarios. Evaluation of these scenarios required the use and integration of various simulation codes. An approach was adapted for this study, whereby results from a particular code were integrated with other codes when necessary. Computational Fluid Dynamics (CFD) methods were used to evaluate the flow field inside the TeSS, from which local gradients for temperature, velocity, and species concentration such as CO (sub 2) could be determined. A model of the TeSS, containing a human, as well as equipment such as a laptop computer, was developed in FLUENT, a finite-volume code. Other factors, such as detailed analysis of the heat transfer through the structure, radiation, and air circulation from the TeSS to the US Laboratory Aisle, where the TeSS is housed, were considered in the model. A complementary model was developed in G189A, a code which has been used by NASA/JSC for environmental control systems analyses since the Apollo program. Boundary conditions were exchanged between the FLUENT and G189A TeSS models. G189A provides human respiration rates to the FLUENT model, while the FLUENT model provides local convective heat transfer coefficients to G189A model. An additional benefit from using an approach with both a systems simulation and CFD model, is the capability to verify the results of each model by comparison to the results of the other model. The G189A and

  15. Interpersonal and group processes in long-term spaceflight crews: perspectives from social and organizational psychology.

    Science.gov (United States)

    Dion, Kenneth L

    2004-07-01

    The issues of interpersonal and group processes in long-term spacecrews from the perspectives of social and organizational psychology are considered here. A contrast between the Amundsen vs. Scott expeditions to the South Pole 90 yrs. ago highlights the importance of personnel selection and attention to interpersonal and group dynamics in expeditions to extreme and dangerous environments, such as long-term spaceflights today. Under the rubric of personnel selection, some further psychological "select-in" and "select-out" criteria are suggested, among them implicit measures of human motivation, intergroup attitudes ("implicit" and "explicit" measures of prejudice, social dominance orientation, and right-wing authoritarianism), attachment styles, and dispositional hardiness. The situational interview and the idea of "selection for teams," drawn from current advances in organizational psychology, are recommended for selecting members for future spacecrews. Under the rubrics of interpersonal and group processes, the social relations model is introduced as a technique for modeling and understanding interdependence among spacecrew members and partialling out variance in behavioral and perceptual data into actor/perceiver, partner/target, and relationship components. Group cohesion as a multidimensional construct is introduced, along with a consideration of the groupthink phenomenon and its controversial link to cohesion. Group composition issues are raised with examples concerning cultural heterogeneity and gender composition. Cultural value dimensions, especially power distance and individual-collectivism, should be taken into account at both societal and psychological levels in long-term space missions. Finally, intergroup processes and language issues in crews are addressed. The recategorization induction from the common ingroup identity model is recommended as a possible intervention for overcoming and inhibiting intergroup biases within spacecrews and between space

  16. Adhesion of Silicone Elastomer Seals for NASA's Crew Exploration Vehicle

    Science.gov (United States)

    deGroh, Henry C., III; Miller, Sharon K. R.; Smith, Ian M.; Daniels, Christopher C.; Steinetz, Bruce M

    2008-01-01

    Silicone rubber seals are being considered for a number of interfaces on NASA's Crew Exploration Vehicle (CEV). Some of these joints include the docking system, hatches, and heat shield-to-back shell interface. A large diameter molded silicone seal is being developed for the Low Impact Docking System (LIDS) that forms an effective seal between the CEV and International Space Station (ISS) and other future Constellation Program spacecraft. Seals between the heat shield and back shell prevent high temperature reentry gases from leaking into the interface. Silicone rubber seals being considered for these locations have inherent adhesive tendencies that would result in excessive forces required to separate the joints if left unchecked. This paper summarizes adhesion assessments for both as-received and adhesion-mitigated seals for the docking system and the heat shield interface location. Three silicone elastomers were examined: Parker Hannifin S0899-50 and S0383-70 compounds, and Esterline ELA-SA-401 compound. For the docking system application various levels of exposure to atomic oxygen (AO) were evaluated. Moderate AO treatments did not lower the adhesive properties of S0899-50 sufficiently. However, AO pretreatments of approximately 10(exp 20) atoms/sq cm did lower the adhesion of S0383-70 and ELA-SA-401 to acceptable levels. For the heat shield-to-back shell interface application, a fabric covering was also considered. Molding Nomex fabric into the heat shield pressure seal appreciably reduced seal adhesion for the heat shield-to-back shell interface application.

  17. Damping Effects of Drogue Parachutes on Orion Crew Module Dynamics

    Science.gov (United States)

    Aubuchon, Vanessa V.; Owens, D. Bruce

    2016-01-01

    Because simulations of the Orion Crew Module (CM) dynamics with drogue parachutes deployed were under-predicting the amount of damping seen in free-flight tests, an attach-point damping model was applied to the Orion system. A key hypothesis in this model is that the drogue parachutes' net load vector aligns with the CM drogue attachment point velocity vector. This assumption seems reasonable and has historically produced good results, but has never been experimentally verified. The wake of the CM influences the drogue parachutes, which makes performance predictions of the parachutes difficult. Many of these effects are not currently modeled in the simulations. A forced oscillation test of the CM with parachutes was conducted in the NASA LaRC 20-Ft Vertical Spin Tunnel (VST) to gather additional data to validate and refine the attach-point damping model. A second loads balance was added to the original Orion VST model to measure the drogue parachute loads independently of the CM. The objective of the test was to identify the contribution of the drogues to CM damping and provide additional information to quantify wake effects and the interactions between the CM and parachutes. The drogue parachute force vector was shown to be highly dependent on the CM wake characteristics. Based on these wind tunnel test data, the attach-point damping model was determined to be a sufficient approximation of the parachute dynamics in relationship to the CM dynamics for preliminary entry vehicle system design. More wake effects should be included to better model the system.

  18. A One-year, Short-Stay Crewed Mars Mission Using Bimodal Nuclear Thermal Electric Propulsion (BNTEP) - A Preliminary Assessment

    Science.gov (United States)

    Burke, Laura A.; Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

    2013-01-01

    A crewed mission to Mars poses a signi cant challenge in dealing with the physiolog- ical issues that arise with the crew being exposed to a near zero-gravity environment as well as signi cant solar and galactic radiation for such a long duration. While long sur- face stay missions exceeding 500 days are the ultimate goal for human Mars exploration, short round trip, short surface stay missions could be an important intermediate step that would allow NASA to demonstrate technology as well as study the physiological e ects on the crew. However, for a 1-year round trip mission, the outbound and inbound hy- perbolic velocity at Earth and Mars can be very large resulting in a signi cant propellant requirement for a high thrust system like Nuclear Thermal Propulsion (NTP). Similarly, a low thrust Nuclear Electric Propulsion (NEP) system requires high electrical power lev- els (10 megawatts electric (MWe) or more), plus advanced power conversion technology to achieve the lower speci c mass values needed for such a mission. A Bimodal Nuclear Thermal Electric Propulsion (BNTEP) system is examined here that uses three high thrust Bimodal Nuclear Thermal Rocket (BNTR) engines allowing short departure and capture maneuvers. The engines also generate electrical power that drives a low thrust Electric Propulsion (EP) system used for ecient interplanetary transit. This combined system can help reduce the total launch mass, system and operational requirements that would otherwise be required for equivalent NEP or Solar Electric Propulsion (SEP) mission. The BNTEP system is a hybrid propulsion concept where the BNTR reactors operate in two separate modes. During high-thrust mode operation, each BNTR provides 10's of kilo- Newtons of thrust at reasonably high speci c impulse (Isp) of 900 seconds for impulsive trans-planetary injection and orbital insertion maneuvers. When in power generation / EP mode, the BNTR reactors are coupled to a Brayton power conversion system allowing each

  19. A One-year, Short-Stay Crewed Mars Mission Using Bimodal Nuclear Thermal Electric Propulsion (BNTEP) - A Preliminary Assessment

    Science.gov (United States)

    Burke, Laura M.; Borowski, Stanley K.; McCurdy, David R.; Packard, Thomas W.

    2013-01-01

    A crewed mission to Mars poses a significant challenge in dealing with the physiological issues that arise with the crew being exposed to a near zero-gravity environment as well as significant solar and galactic radiation for such a long duration. While long surface stay missions exceeding 500 days are the ultimate goal for human Mars exploration, short round trip, short surface stay missions could be an important intermediate step that would allow NASA to demonstrate technology as well as study the physiological effects on the crew. However, for a 1-year round trip mission, the outbound and inbound hyperbolic velocity at Earth and Mars can be very large resulting in a significant propellant requirement for a high thrust system like Nuclear Thermal Propulsion (NTP). Similarly, a low thrust Nuclear Electric Propulsion (NEP) system requires high electrical power levels (10 megawatts electric (MWe) or more), plus advanced power conversion technology to achieve the lower specific mass values needed for such a mission. A Bimodal Nuclear Thermal Electric Propulsion (BNTEP) system is examined here that uses three high thrust Bimodal Nuclear Thermal Rocket (BNTR) engines allowing short departure and capture maneuvers. The engines also generate electrical power that drives a low thrust Electric Propulsion (EP) system used for efficient interplanetary transit. This combined system can help reduce the total launch mass, system and operational requirements that would otherwise be required for equivalent NEP or Solar Electric Propulsion (SEP) mission. The BNTEP system is a hybrid propulsion concept where the BNTR reactors operate in two separate modes. During high-thrust mode operation, each BNTR provides 10's of kilo-Newtons of thrust at reasonably high specific impulse (Isp) of 900 seconds for impulsive transplanetary injection and orbital insertion maneuvers. When in power generation/EP mode, the BNTR reactors are coupled to a Brayton power conversion system allowing each

  20. Harmonious Co-Existence between Green and Black——Story about GW106 Drilling Crew "The Best Environment-Friendly Crew"

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ Stepping into the well site of Rig Crew GW106 from GreatWall Drilling Company Venezuela) in Venezuela, you will be amazed by what you see. No splashing sludge or muddy roads, instead, what before you are spotless drilling equipment. All the workers in clean and glaring uniforms work busily yet in an orderly way.

  1. Two cases of atmospheric escape in the Solar System: Titan and Earth

    Science.gov (United States)

    Dandouras, I.

    2012-01-01

    Escape into space of the constituents of a planetary upper atmosphere can occur either in the form of neutral gas (thermal escape or non-thermal escape), or in the form of plasma. The long-term stability of an atmosphere results from the balance between source and escape rates. Two cases will be examined: Titan and Earth. Titan is the second largest planetary satellite in the Solar System and is the only one that has an atmosphere as substantial as that of the Earth. Titan's nitrogen rich atmosphere is embedded within Saturn's magnetosphere, and is directly bombarded by energetic ions due to Titan's lack of a significant intrinsic magnetic field. In addition to thermal escape, energy input from Saturn's magnetosphere and from Solar UV radiation can drive several non-thermal escape mechanisms in Titan's upper atmosphere: sputtering, dissociation and dissociative ionization of molecular nitrogen producing pick-up ions, photochemical production of fast neutrals etc. Earth also constantly loses matter, mostly in the form of H+ and O+ ions, through various outflow processes from the upper atmosphere and ionosphere. Most of the ions are low-energy (plasma reservoir is the plasmasphere, which is a toroidal region encircling the Earth and containing cold and dense plasma. Plasma plumes, forming in the outer plasmasphere and released outwards, constitute a well-established mode for plasmaspheric material release to the magnetosphere. They are associated to geomagnetically active periods and the related electric field change. In 1992 Lemaire and Shunk proposed the existence of an additional mode for plasmaspheric material release and escape: a plasmaspheric wind, steadily transporting cold plasmaspheric plasma outwards across the geomagnetic field lines. This has been proposed on a theoretical basis. Direct detection of this wind has, however, eluded observation in the past. Analysis of ion measurements, acquired in the outer plasmasphere by the CIS experiment onboard the

  2. Exosomes as a tumor immune escape mechanism: possible therapeutic implications

    Directory of Open Access Journals (Sweden)

    Hanley Harold H

    2008-07-01

    Full Text Available Abstract Advances in cancer therapy have been substantial in terms of molecular understanding of disease mechanisms, however these advances have not translated into increased survival in the majority of cancer types. One unsolved problem in current cancer therapeutics is the substantial immune suppression seen in patients. Conventionally, investigations in this area have focused on antigen-nonspecific immune suppressive molecules such as cytokines and T cell apoptosis inducing molecules such as Fas ligand. More recently, studies have demonstrated nanovesicle particles termed exosomes are involved not only in stimulation but also inhibition of immunity in physiological conditions. Interestingly, exosomes secreted by cancer cells have been demonstrated to express tumor antigens, as well as immune suppressive molecules such as PD-1L and FasL. Concentrations of exosomes from plasma of cancer patients have been associated with spontaneous T cell apoptosis, which is associated in some situations with shortened survival. In this paper we place the "exosome-immune suppression" concept in perspective of other tumor immune evasion mechanisms. We conclude by discussing a novel therapeutic approach to cancer immune suppression by extracorporeal removal of exosomes using hollow fiber filtration technology

  3. 1985 NASA-Rockwell Space Station Crew Safety Study: results from Mir.

    Science.gov (United States)

    Dudley-Rowley, M; Cohen, M M; Flores, P

    2004-01-01

    In 1985, Rockwell International (now Boeing--North American) completed the Space Station Crew Safety Alternatives Study for NASA. This five-volume study identified a wide range of potential safety threats and hazards that the crew might encounter on the future International Space Station. These threats included fire, explosion, collision, decompression, contamination, and radiation, among many others. One volume focused on the human factors aspects of safety, featuring the Crew Safety-Human Factors Interaction Model. In this model, a stressor (such as one of the threats) can lead to degraded performance, which can contribute to human error, unless appropriate and effective countermeasures are available to the crew. In 1986, the Soviet Union launched the Mir Space Station, the "second generation" that followed the Salyut series of space stations. The Mir was designed for a five-year life on orbit. It remained in use for fourteen years. During the first ten years, it performed well, with few safety issues. However, during the last four years, the aging station--operating at more than two times beyond its design lifetime--encountered a variety of safety hazards and human factors issues. Despite these often serious problems, the Mir crews always found a way to save the station, and no crew member was seriously injured or killed. This paper evaluates the safety record on Mir, and compares it to the NASA-Rockwell study, that was contemporaneous with the construction and launch of Mir. This comparison and analysis can provide a foundation for future space crew safety and related human factors support.

  4. Use of Data Comm by Flight Crew to Conduct Interval Management Operations to Parallel Dependent Runways

    Science.gov (United States)

    Baxley, Brian T.; Hubbs, Clay; Shay, Rick; Karanian, James

    2011-01-01

    The Interval Management (IM) concept is being developed as a method to maintain or increase high traffic density airport arrival throughput while allowing aircraft to conduct near idle thrust descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR1) experiment at NASA Langley Research Center used 24 commercial pilots to examine IM procedures to conduct parallel dependent runway arrival operations while maintaining safe but efficient intervals behind the preceding aircraft. The use of IM procedures during these operations requires a lengthy and complex clearance from Air Traffic Control (ATC) to the participating aircraft, thereby making the use of Controller Pilot Data Link Communications (CPDLC) highly desirable as the communication method. The use of CPDLC reduces the need for voice transmissions between controllers and flight crew, and enables automated transfer of IM clearance elements into flight management systems or other aircraft avionics. The result is reduced crew workload and an increase in the efficiency of crew procedures. This paper focuses on the subset of data collected related to the use of CPDLC for IM operations into a busy airport. Overall, the experiment and results were very successful, with the mean time under 43 seconds for the flight crew to load the clearance into the IM spacing tool, review the calculated speed, and respond to ATC. An overall mean rating of Moderately Agree was given when the crews were asked if the use of CPDLC was operationally acceptable as simulated in this experiment. Approximately half of the flight crew reported the use of CPDLC below 10,000 for IM operations was unacceptable, with 83% reporting below 5000 was unacceptable. Also described are proposed modifications to the IM operations that may reduce CPDLC Respond time to less than 30 seconds and should significantly reduce the complexity of crew procedures, as well as follow-on research issues for operational use of CPDLC during IM

  5. Modeling the endosomal escape of cell-penetrating peptides: transmembrane pH gradient driven translocation across phospholipid bilayers.

    Science.gov (United States)

    Magzoub, Mazin; Pramanik, Aladdin; Gräslund, Astrid

    2005-11-15

    Cell-penetrating peptides (CPPs) are able to mediate the efficient cellular uptake of a wide range of cargoes. Internalization of a number of CPPs requires uptake by endocytosis, initiated by binding to anionic cell surface heparan sulfate (HS), followed by escape from endosomes. To elucidate the endosomal escape mechanism, we have modeled the process for two CPPs: penetratin (pAntp) and the N-terminal signal peptide of the unprocessed bovine prion protein (bPrPp). Large unilamellar phospholipid vesicles (LUVs) were produced encapsulating either peptide, and an ionophore, nigericin, was used to create a transmembrane pH gradient (DeltapH(mem), inside acidic) similar to the one arising in endosomes in vivo. In the absence of DeltapH(mem), no pAntp escape from the LUVs is observed, while a fraction of bPrPp escapes. In the presence of DeltapH(mem), a significant amount of pAntp escapes and an even higher degree of bPrPp escape takes place. These results, together with the differences in kinetics of escape, indicate different escape mechanisms for the two peptides. A minimum threshold peptide concentration exists for the escape of both peptides. Coupling of the peptides to a cargo reduces the fraction escaping, while complexation with HS significantly hinders the escape. Fluorescence correlation spectroscopy results show that during the escape process the LUVs are intact. Taken together, these results suggest a model for endosomal escape of CPPs: DeltapH(mem)-mediated mechanism, following dissociation from HS of the peptides, above a minimum threshold peptide concentration, in a process that does not involve lysis of the vesicles.

  6. Providing Oxygen for the Crew of a Lunar Outpost

    Science.gov (United States)

    Ewert, Michael K.; Jeng, Frank; Conger, Bruce; Anderson, Molly S.

    2009-01-01

    Oxygen (O2) is obviously essential for human space missions, but it is important to examine all the different ways it will be used and the potential sources that it may come from. This effort will lead to storage and delivery requirements and help to determine the optimum architecture from an overall systems engineering point of view. Accounting for all the oxygen in a Lunar Outpost mission includes meeting the metabolic needs of the crew while in the surface Habitat, leakage through the Habitat or Pressurized Rover walls, recharge of the space suit backpack and emergency situations. Current plans indicate that both primary and secondary O2 bottles for the space suit will be filled to a pressure of 20.7 MPa (3000 psia). Other uses of O2 require much lower pressure. Sources of O2 at a Lunar Outpost include compressed or liquefied O2 brought along specifically for life support, scavenged O2 from the Lander propulsion system, recovered O2 from waste water or exhaled carbon dioxide and O2 mined from the moon itself. Previously, eight technology options were investigated to provide the high pressure space suit O2. High pressure O2 storage was treated as the baseline technology and compared to the other seven. The other seven were cryogenic storage followed by high pressure vaporization, scavenging liquid oxygen (LOX) from Lander followed by vaporization, LOX delivery followed by sorption compression, low pressure water electrolysis followed by mechanical compression, high pressure water electrolysis, sharing a high pressure electrolyzer with a regenerative fuel cell power system, and making use of In- Situ Resource Utilization (ISRU). This system-level analysis was conducted by comparing equivalent system mass of the eight technologies in open and closed loop life support architectures. The most promising high pressure O2 generation technologies were recommended for development. Updates and an expansion of the earlier study have been made and the results are reported in

  7. IMF-induced escape of molecular ions from the Martian ionosphere

    Directory of Open Access Journals (Sweden)

    Y. Kubota

    2013-08-01

    Full Text Available Since Mars does not possess a significant global intrinsic magnetic field, the solar wind interacts directly with the Martian ionosphere and can induce ion escapes from it. Phobos-2 and recent Mars Express (MEX observations have shown that the escaping ions are O+ as well as molecular O2+ and CO2+. While O+ escape can be understood by the ion pick-up of non-thermal O corona extended around the planet, regarding the heavy molecular O2+ and CO2+, which are buried in the lower ionosphere, a novel escape mechanism needs to considered. Here we attack this problem by global magnetohydrodynamic (MHD simulations. First, we clarify the global structure of the streamlines that result from the interaction with the solar wind. Then, by focusing on the streamlines that dip into the low-altitude part of the dayside ionosphere, we investigate the escape path of the molecular ions. The effects of the interplanetary magnetic field (IMF on the molecular ion escape process are investigated by comparing the results with and without IMF. IMF has little effect on O+ escape via ion pick-up mediated by solar wind electron impact ionization of the O corona. O2+ and CO2+ are shoveled from the low-altitude regions of the dayside ionosphere by magnetic tension in the presence of IMF. These ions are pulled by the U-shaped field lines to the north and south poles, and at the terminator, they are concentrated in the noon–midnight meridian plane. These ions remain confined to the noon–midnight plane as they are transported to the nightside to form the tail ray. Then they escape along the streamlines open to the interplanetary space. Under a typical solar wind and IMF condition expected at Mars, O+, O2+ and CO2+ escape fluxes are 8.0 × 1023, 3.5 × 1023 and 5.0 × 1022 ion s−1, respectively, which are in good agreement with the MEX observations.

  8. Extinction Correction Significantly Influences the Estimate of the Lyα Escape Fraction

    Science.gov (United States)

    An, Fang Xia; Zheng, Xian Zhong; Hao, Cai-Na; Huang, Jia-Sheng; Xia, Xiao-Yang

    2017-02-01

    The Lyα escape fraction is a key measure to constrain the neutral state of the intergalactic medium and then to understand how the universe was fully reionized. We combine deep narrowband imaging data from the custom-made filter NB393 and the {{{H}}}2S1 filter centered at 2.14 μm to examine the Lyα emitters and Hα emitters at the same redshift z = 2.24. The combination of these two populations allows us to determine the Lyα escape fraction at z = 2.24. Over an area of 383 arcmin2 in the Extended Chandra Deep Field South (ECDFS), 124 Lyα emitters are detected down to NB393 = 26.4 mag at the 5σ level, and 56 Hα emitters come from An et al. Of these, four have both Lyα and Hα emissions (LAHAEs). We also collect the Lyα emitters and Hα emitters at z = 2.24 in the COSMOS field from the literature, and increase the number of LAHAEs to 15 in total. About one-third of them are AGNs. We measure the individual/volumetric Lyα escape fraction by comparing the observed Lyα luminosity/luminosity density to the extinction-corrected Hα luminosity/luminosity density. We revisit the extinction correction for Hα emitters using the Galactic extinction law with color excess for nebular emission. We also adopt the Calzetti extinction law together with an identical color excess for stellar and nebular regions to explore how the uncertainties in extinction correction affect the estimate of individual and global Lyα escape fractions. In both cases, an anti-correlation between the Lyα escape fraction and dust attenuation is found among the LAHAEs, suggesting that dust absorption is responsible for the suppression of the escaping Lyα photons. However, the estimated Lyα escape fraction of individual LAHAEs varies by up to ∼3 percentage points between the two methods of extinction correction. We find the global Lyα escape fraction at z = 2.24 to be (3.7 ± 1.4)% in the ECDFS. The variation in the color excess of the extinction causes a discrepancy of ∼1 percentage

  9. Methodology and Assumptions of Contingency Shuttle Crew Support (CSCS) Calculations Using ISS Environmental Control and Life Support Systems

    Science.gov (United States)

    Prokhorov, Kimberlee; Shkedi, Brienne

    2006-01-01

    The current International Space Station (ISS) Environmental Control and Life Support (ECLS) system is designed to support an ISS crew size of three people. The capability to expand that system to support nine crew members during a Contingency Shuttle Crew Support (CSCS) scenario has been evaluated. This paper describes how the ISS ECLS systems may be operated for supporting CSCS, and the durations expected for the oxygen supply and carbon dioxide control subsystems.

  10. The Escape of Ionizing Photons from OB Associations in Disk Galaxies Radiation Transfer Through Superbubbles

    CERN Document Server

    Dove, J B; Ferrara, A; Dove, James B.; Ferrara, Andrea

    1999-01-01

    By solving the time-dependent radiation transfer problem of stellar radiation through evolving superbubbles within a smoothly varying H I distribution, we have estimated the fraction of ionizing photons emitted by OB associations that escapes the H I disk of our Galaxy. We considered a coeval star-formation history and a Gaussian star-formation history with a time spread sigma_t = 2 Myr. We find that the shells of the expanding superbubbles quickly trap or attenuate the ionizing flux, such that most of the escaping radiation escapes shortly after the formation of the superbubble. Superbubbles of large associations can blowout of the H I disk and form dynamic chimneys, which allow the ionizing radiation directly to escape the H I disk. However, blowout occurs when the ionizing photon luminosity has dropped well below the association's maximum luminosity. For the coeval star-formation history, the fraction of photons that escape each side of the disk in the solar vicinity is f_esc approx 6% (the total fraction ...

  11. Sputtering at Mars: MAVEN observations of precipitating and escaping oxygen during nominal and extreme conditions

    Science.gov (United States)

    Curry, Shannon; Luhmann, Janet; Dong, Chuanfei; Ma, Yingjuan; Leblanc, Francois; Modolo, Ronan; Brain, David; Gruesbeck, Jacob; Hara, Takuya; Halekas, Jasper; Dong, Yaxue; Williamson, Hayley N.; Johnson, Robert E.; McFadden, James; Espley, Jared R.; Mitchell, David; Connerney, Jack; Eparvier, Frank; Lillis, Robert J.; Jakosky, Bruce

    2016-10-01

    Sputtering is believed to be one of the dominant escape mechanisms during the early epochs of our solar system when the solar activity and EUV intensities were much higher than the present day. Mars lacks a global dynamo magnetic field, which creates a scenario where the solar wind directly interacts with the upper atmosphere and newly created ions can be picked up and swept away by the background convection electric field. These pick-up ions can directly escape or precipitate back into the atmosphere and induce atmospheric sputtering of neutrals.The MAVEN spacecraft has observed the Mars upper atmosphere, ionosphere, magnetic topology and interactions with the Sun and solar wind during numerous Interplanetary Coronal Mass Ejection (ICME) impacts spanning from March 2015 to June 2016. ICMEs are associated with enhanced solar wind velocities, densities and magnetic field strength, and often drive heavy ion precipitation at much higher rates than during nominal conditions. Thus, ICMEs provide a unique environment for observing sputtering. We will compare MAVEN observations of heavy ion precipitation during nominal conditions as well as during ICMEs. Additionally, we will present global MHD and test particle simulations of the ICMEs in order to calculate sputtering escape rates for oxygen. Finally, we will use the observed and modeled sputtering escape rates to provide an initial estimate of the total sputtered atmospheric escape from Mars over billions of years.

  12. How Hospitable Are Space Weather Affected Habitable Zones? The Role of Ion Escape

    Science.gov (United States)

    Airapetian, Vladimir S.; Glocer, Alex; Khazanov, George V.; Loyd, R. O. P.; France, Kevin; Sojka, Jan; Danchi, William C.; Liemohn, Michael W.

    2017-02-01

    Atmospheres of exoplanets in the habitable zones around active young G-K-M stars are subject to extreme X-ray and EUV (XUV) fluxes from their host stars that can initiate atmospheric erosion. Atmospheric loss affects exoplanetary habitability in terms of surface water inventory, atmospheric pressure, the efficiency of greenhouse warming, and the dosage of the UV surface irradiation. Thermal escape models suggest that exoplanetary atmospheres around active K-M stars should undergo massive hydrogen escape, while heavier species including oxygen will accumulate forming an oxidizing atmosphere. Here, we show that non-thermal oxygen ion escape could be as important as thermal, hydrodynamic H escape in removing the constituents of water from exoplanetary atmospheres under supersolar XUV irradiation. Our models suggest that the atmospheres of a significant fraction of Earth-like exoplanets around M dwarfs and active K stars exposed to high XUV fluxes will incur a significant atmospheric loss rate of oxygen and nitrogen, which will make them uninhabitable within a few tens to hundreds of Myr, given a low replenishment rate from volcanism or cometary bombardment. Our non-thermal escape models have important implications for the habitability of the Proxima Centauri’s terrestrial planet.

  13. Escape from Telomere-Driven Crisis Is DNA Ligase III Dependent

    Directory of Open Access Journals (Sweden)

    Rhiannon E. Jones

    2014-08-01

    Full Text Available Short dysfunctional telomeres are capable of fusion, generating dicentric chromosomes and initiating breakage-fusion-bridge cycles. Cells that escape the ensuing cellular crisis exhibit large-scale genomic rearrangements that drive clonal evolution and malignant progression. We demonstrate that there is an absolute requirement for fully functional DNA ligase III (LIG3, but not ligase IV (LIG4, to facilitate the escape from a telomere-driven crisis. LIG3- and LIG4-dependent alternative (A and classical (C nonhomologous end-joining (NHEJ pathways were capable of mediating the fusion of short dysfunctional telomeres, both displaying characteristic patterns of microhomology and deletion. Cells that failed to escape crisis exhibited increased proportions of C-NHEJ-mediated interchromosomal fusions, whereas those that escaped displayed increased proportions of intrachromosomal fusions. We propose that the balance between inter- and intrachromosomal telomere fusions dictates the ability of human cells to escape crisis and is influenced by the relative activities of A- and C-NHEJ at short dysfunctional telomeres.

  14. EFFECT OF ESCAPE DEVICE FOR SUBMERGED FLOATING TUNNEL (SFT) ON HYDRODYNAMIC LOADS APPLIED TO SFT

    Institute of Scientific and Technical Information of China (English)

    DONG Man-sheng; MIAO Guo-ping; YONG Long-chang; NIU Zhong-rong; PANG Huan-ping; HOU Chao-qun

    2012-01-01

    This paper presents a potential approach to settle the problem of surviving major safety accidents in Submerged Floating Tunnel (SFT) that detachable emergency escape devices are set up outside SFT.The Computational Fluid Dynamics (CFD)technology is used to investigate the effect of emergency escape devices on the hydrodynamic load acting on SFT in uniform and oscillatory flows and water waves by numerical test.The governing equations,i.e.,the Reynolds-Averaged Navier-Stokes (RANS)equations and k - ε standard turbulence equations,are solved by the Finite Volume Method (FVM).Analytic solutions for the Airy wave are applied to set boundary conditions to generate water wave.The VOF method is used to trace the free surface.In uniform flow,hydrodynamic loads,applied to SFT with emergency escape device,reduce obviously.But,in oscillatory flow,it has little influence on hydrodynamic loads acting on SFT.Horizontal and vertical wave loads of SFT magnify to some extend due to emergency escape devices so that the influence of emergency escape devices on hydrodynamic loads of SFT should be taken into consideration when designed.

  15. Selectivity of escape-hole size in tube traps for whitespotted conger Conger myriaster

    Institute of Scientific and Technical Information of China (English)

    YANG Bingzhong; TANG Yanli; LIANG Zhenlin

    2011-01-01

    Comparative fishing experiments were carried out in 2010 using tube traps with five hole diameters (8,15,18,20 and 22 mm) to establish the size selectivity of escape holes for white-spotted conger.Selectivity and split parameters of the SELECT model were calculated using the estimated-split and equal-spilt model.From likelihood ratio tests and AIC (Akaike's Information Criterion) values,the estimated-split model was selected as the best-fit model.Size selectivity of escape holes in the tube traps was expressed as a logistic curve,similar to mesh selectivity.The 50% selection length of white-spotted conger in the estimated-split model was 28.26,33.35,39.31 and 47.30 cm for escape-hole diameters of 15,18,20 and 22 mm,respectively.The optimum escape-hole size is discussed with respect to management of the white-spotted conger fishery.The results indicate that tube traps with escape holes of 18 mm in diameter would benefit this fishery.

  16. Orion Pad Abort 1 Crew Module Mass Properties Test Approach and Results

    Science.gov (United States)

    Herrera, Claudia; Harding, Adam

    2012-01-01

    The Flight Loads Laboratory at the Dryden Flight Research Center conducted tests to measure the inertia properties of the Orion Pad Abort 1 (PA-1) Crew Module (CM). These measurements were taken to validate analytical predictions of the inertia properties of the vehicle and assist in reducing uncertainty for derived aero performance coefficients to be calculated post-launch. The first test conducted was to determine the Ixx of the Crew Module. This test approach used a modified torsion pendulum test setup that allowed the suspended Crew Module to rotate about the x axis. The second test used a different approach to measure both the Iyy and Izz properties. This test used a Knife Edge fixture that allowed small rotation of the Crew Module about the y and z axes. Discussions of the techniques and equations used to accomplish each test are presented. Comparisons with the predicted values used for the final flight calculations are made. Problem areas, with explanations and recommendations where available, are addressed. Finally, an evaluation of the value and success of these techniques to measure the moments of inertia of the Crew Module is provided.

  17. Influence of the helicopter environment on patient care capabilities: flight crew perceptions

    Science.gov (United States)

    Myers, K. J.; Rodenberg, H.; Woodard, D.

    1995-01-01

    INTRODUCTION: Flight crew perceptions of the effect of the rotary-wing environment on patient-care capabilities have not been subject to statistical analysis. We hypothesized that flight crew members perceived significant difficulties in performing patient-care tasks during air medical transport. METHODS: A survey was distributed to a convenience sample of flight crew members from 20 flight programs. Respondents were asked to compare the difficulty of performing patient-care tasks in rotary-wing and standard (emergency department or intensive care unit) settings. Demographic data collected on respondents included years of flight experience, flights per month, crew duty position and primary aircraft in which the respondent worked. Statistical analysis was performed as appropriate using Student's t-test, type III sum of squares, and analysis of variance. Alpha was defined as p responded. All tasks were significantly rated more difficult in the rotary-wing environment. Ratings were not significantly correlated with flight experience, duty position, flights per month or aircraft used. CONCLUSIONS: We conclude that the performance of patient-care tasks are perceived by air medical flight crew to be significantly more difficult during rotary-wing air medical transport than in hospital settings.

  18. Personal values and crew compatibility: Results from a 105 days simulated space mission

    Science.gov (United States)

    Sandal, Gro M.; Bye, Hege H.; van de Vijver, Fons J. R.

    2011-08-01

    On a mission to Mars the crew will experience high autonomy and inter-dependence. "Groupthink", known as a tendency to strive for consensus at the cost of considering alternative courses of action, represents a potential safety hazard. This paper addresses two aspects of "groupthink": the extent to which confined crewmembers perceive increasing convergence in personal values, and whether they attribute less tension to individual differences over time. It further examines the impact of personal values for interpersonal compatibility. These questions were investigated in a 105-day confinement study in which a multinational crew ( N=6) simulated a Mars mission. The Portrait of Crew Values Questionnaire was administered regularly to assess personal values, perceived value homogeneity, and tension attributed to value disparities. Interviews were conducted before and after the confinement. Multiple regression analysis revealed no significant changes in value homogeneity over time; rather the opposite tendency was indicated. More tension was attributed to differences in hedonism, benevolence and tradition in the last 35 days when the crew was allowed greater autonomy. Three subgroups, distinct in terms of personal values, were identified. No evidence for "groupthink" was found. The results suggest that personal values should be considered in composition of crews for long duration missions.

  19. Inter- vs intra-individual variation and temporal repeatability of escape responses in the coral reef fish Amblyglyphidodon curacao

    Directory of Open Access Journals (Sweden)

    Maïwenn Jornod

    2015-11-01

    Full Text Available Fast-start escape responses are critical behaviours used by fishes during predator-prey encounters and some interactions with hetero- and conspecifics. In experimental studies, escape responses are often measured once per individual and considered representative of maximum performance. However, few studies have compared variability and repeatability in escape performances within and among individuals. Using the tropical damselfish Amblyglyphidodon curacao, we quantified inter- and intra-individual variation in behavioural and kinematic components of escape performance during repeated presentations of a stimulus at 15 min intervals. Individual maximum escape performance was repeatable through time, but there was considerable variation in the magnitude of responses both among and within fish. We found no evidence of habituation or fatigue due to repeated stimulations, suggesting that fish can be stimulated multiple times to ensure that an accurate estimate of maximum escape performance is obtained.

  20. 3D Simulations of the variability of the atmospheric escape at Mars with the EUV solar flux

    Science.gov (United States)

    Chaufray, J.-Y.; Leblanc, F.; Modolo, R.; Gonzalez-Galindo, F.; Lopez-Valverde, M.; Forget, F.

    2014-04-01

    The exosphere is the collisionless region surrounding a planetary atmosphere. The exosphere of Mars is an important region to characterize the escape processes. It is mainly formed from processes responsible of the atmospheric escape in the underlying atmosphere/ionosphere. The Martian exosphere is mainly composed of atomic hydrogen, molecular hydrogen and atomic oxygen. Atomic and molecular hydrogen escape is dominated by the thermal escape while the oxygen escape is dominated by the O2+ dissociative recombination in the Martian upper ionosphere. Therefore their escape rates are expected to vary strongly with the EUV solar flux which is the main driver of the heating and ionization of the Martian upper atmosphere. In this presentation, we will present simulations obtained from a 3D Martian exospheric model, coupled to the 3D GCM-LMD model for different solar UV conditions representative of current and past conditions.